Reject oversized step-repeat expansions

Applies github PR #1. Thanks to @SaumyaShah08 on github!

.coveragerc

@@ -1,8 +0,0 @@
-[run]
-branch = True
-source = gerber
-
-[report]
-ignore_errors = True
-omit =
-    gerber/tests/*

.github/workflows/pcb-tools.yml

@@ -1,45 +0,0 @@
-name: pcb-tools
-
-on: [push, pull_request]
-
-jobs:
-  test:
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version: [3.5, 3.6, 3.7, 3.8]
-
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v1
-      - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v1
-        with:
-          python-version: ${{ matrix.python-version }}
-      - name: Install dependencies
-        run: |
-          pip install -r requirements-dev.txt
-      - name: Test with pytest
-        run: |
-          pytest
-  coverage:
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v1
-      - name: Set up Python 3.8
-        uses: actions/setup-python@v1
-        with:
-          python-version: 3.8
-      - name: Install dependencies
-        run: |
-          pip install -r requirements-dev.txt
-      - name: Run coverage
-        run: |
-          make test-coverage
-      - uses: codecov/codecov-action@v1
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          file: ./coverage.xml
-          flags: unittest

.gitignore

@@ -3,3 +3,5 @@ gerbonara_test_failures
 __pycache__
 .tox
 docs/_build/
+build
+dist

.gitlab-ci.yml

@@ -13,32 +13,62 @@ build:archlinux:
   variables:
     GIT_SUBMODULE_STRATEGY: none
   script:
-    - pip3 install --user wheel
-    - python3 setup.py bdist_wheel
+    - git config --global --add safe.directory "$CI_PROJECT_DIR"
+    - uv build
   artifacts:
     name: "gerbolyze-$CI_COMMIT_REF_NAME-gerbonara"
     paths:
-      - dist/*.whl
+      - dist/*
 
-test:archlinux:
-  stage: test
-  image: "registry.gitlab.com/gerbolyze/build-containers/archlinux:latest"
-  script:
-    - pip3 install --user pytest
-    - ~/.local/bin/pytest -o 'testpaths=gerbonara/tests' -o 'norecursedirs=*'
-  dependencies:
-    - build:archlinux
-  artifacts:
-    name: "gerbolyze-$CI_COMMIT_REF_NAME-gerbonara"
-    when: on_failure
-    paths:
-      - gerbonara_test_failures/*
+# FIXME: disable tests since (a) currenty kicad-cli is broken (aborts on start), and the workaround of using an older
+# version from the KiCad project's kicad-cli containers does not work in gitlab CI. Pain.
+#test:archlinux:
+#  stage: test
+#  image: "registry.gitlab.com/gerbolyze/build-containers/archlinux:latest"
+#  script:
+#    - git clone --depth 1 https://gitlab.com/kicad/libraries/kicad-symbols
+#    - git clone --depth 1 https://gitlab.com/kicad/libraries/kicad-footprints
+#    - env KICAD_SYMBOLS=kicad-symbols KICAD_FOOTPRINTS=kicad-footprints pytest -o 'testpaths=gerbonara/tests' -o 'norecursedirs=*'
+#  dependencies:
+#    - build:archlinux
+#  cache:
+#    key: test-image-cache
+#    paths:
+#      - gerbonara/tests/image_cache/*.svg
+#      - gerbonara/tests/image_cache/*.png
+#  artifacts:
+#    name: "gerbolyze-$CI_COMMIT_REF_NAME-gerbonara"
+#    when: on_failure
+#    paths:
+#      - gerbonara_test_failures/*
+#
+#test:ubuntu-rolling:
+#  stage: test
+#  image: "registry.gitlab.com/gerbolyze/build-containers/ubuntu:rolling"
+#  script:
+#    - python3 -m pip install --break-system-packages pytest beautifulsoup4 pillow numpy slugify lxml click scipy
+#    - git clone --depth 1 https://gitlab.com/kicad/libraries/kicad-symbols
+#    - git clone --depth 1 https://gitlab.com/kicad/libraries/kicad-footprints
+#    - env KICAD_SYMBOLS=kicad-symbols KICAD_FOOTPRINTS=kicad-footprints python3 -m pytest -o 'testpaths=gerbonara/tests' -o 'norecursedirs=*'
+#  dependencies:
+#    - build:archlinux
+#  cache:
+#    key: test-image-cache
+#    paths:
+#      - gerbonara/tests/image_cache/*.svg
+#      - gerbonara/tests/image_cache/*.png
+#  artifacts:
+#    name: "gerbolyze-$CI_COMMIT_REF_NAME-gerbonara"
+#    when: on_failure
+#    paths:
+#      - gerbonara_test_failures/*
 
 docs:archlinux:
   stage: test
   image: "registry.gitlab.com/gerbolyze/build-containers/archlinux:latest"
   script:
-    - ~/.local/bin/sphinx-build -E docs docs/_build
+    - git config --global --add safe.directory "$CI_PROJECT_DIR"
+    - sphinx-build -E docs docs/_build
   dependencies:
     - build:archlinux
   artifacts:
@@ -54,7 +84,8 @@ publish:gerbonara:
   cache: {}
   script:
     - export TWINE_USERNAME TWINE_PASSWORD
-    - ~/.local/bin/twine upload dist/*
+    - pip3 install --user --break-system-packages twine rich
+    - twine upload dist/*
   dependencies:
     - build:archlinux
   only:
@@ -66,12 +97,13 @@ pages:
     GIT_SUBMODULE_STRATEGY: none
   image: "registry.gitlab.com/gerbolyze/build-containers/archlinux:latest"
   script:
-    - ~/.local/bin/sphinx-build -E docs docs/_build
+    - git config --global --add safe.directory "$CI_PROJECT_DIR"
+    - sphinx-build -E docs public
   dependencies:
     - build:archlinux
   artifacts:
     paths:
-      - docs/_build
+      - public
   only:
     - /^v.*$/
 

.pypirc

@@ -1,12 +0,0 @@
-[distutils]
-index-servers =
-    pypi
-    testpypi
-
-[pypi]
-username = __token__
-password = ${env.PYPI_TOKEN}
-
-[testpypi]
-username = __token__
-password = ${env.TESTPYPI_TOKEN}

MANIFEST.in

@@ -0,0 +1,11 @@
+include README.md
+include LICENSE
+include MANIFEST.in
+include setup.py
+graft gerbonara
+graft docs
+graft examples
+
+prune gerbonara/tests
+prune **/__pycache__
+prune docs/_build

Makefile

@@ -1,45 +1,45 @@
+PYTHON ?= python
+PYTEST ?= pytest
+SPHINX_BUILD ?= sphinx-build
 
-PYTHON 			?= python
-PYTEST 			?= pytest
-SPHINX_BUILD	?= sphinx-build
+.DEFAULT_GOAL := help
+
+.PHONY: clean docs test test-coverage install sdist bdist_wheel upload testupload help
 
 all: docs sdist bdist_wheel
 
-.PHONY: clean
-clean:
+clean:  ## Clean up project directory
 	find . -name '*.pyc' -delete
 	rm -rf *.egg-info
 	rm -f .coverage
 	rm -f coverage.xml
 	rm -rf docs/_build
 
-.PHONY: docs
-docs:
+docs:  ## Generate documentation
 	sphinx-build -E docs docs/_build
 
-.PHONY: test
-test:
+test:  ## Run tests
 	$(PYTEST)
 
-.PHONY: test-coverage
-test-coverage:
+test-coverage:  ## Generate coverage
 	rm -f .coverage
 	rm -f coverage.xml
 	$(PYTEST) --cov=./ --cov-report=xml 
 
-.PHONY: install
-install:
+install:  ## Install locally
 	PYTHONPATH=. $(PYTHON) setup.py install
 
-sdist:
+sdist:  ## Build source distribution
 	python3 setup.py sdist
 
-bdist_wheel:
+bdist_wheel:  ## Build binary distribution
 	python3 setup.py bdist_wheel
 
-upload: sdist bdist_wheel
+upload: sdist bdist_wheel  ## Upload Python package to PyPI
 	twine upload -s -i gerbonara@jaseg.de --config-file ~/.pypirc --skip-existing --repository pypi dist/*
 
-testupload: sdist bdist_wheel
+testupload: sdist bdist_wheel  ## Upload Python package to test PyPI
 	twine upload --config-file ~/.pypirc --skip-existing --repository testpypi dist/*
 
+help:  ## Display this help
+	@grep -h -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'

README.md

@@ -1,5 +1,5 @@
-[![pipeline status](https://gitlab.com/gerbonara/gerbonara/badges/master/pipeline.svg)](https://gitlab.com/gerbonara/gerbonara/commits/master)
-[![coverage report](https://gitlab.com/gerbonara/gerbonara/badges/master/coverage.svg)](https://gitlab.com/gerbonara/gerbonara/commits/master)
+[![pipeline status](https://gitlab.com/gerbolyze/gerbonara/badges/master/pipeline.svg)](https://gitlab.com/gerbolyze/gerbonara/commits/master)
+[![coverage report](https://gitlab.com/gerbolyze/gerbonara/badges/master/coverage.svg)](https://gitlab.com/gerbolyze/gerbonara/commits/master)
 [![pypi](https://img.shields.io/pypi/v/gerbonara)](https://pypi.org/project/gerbonara/)
 [![aur](https://img.shields.io/aur/version/python-gerbonara)](https://aur.archlinux.org/packages/python-gerbonara/)
 
@@ -23,28 +23,20 @@ yay -S python-gerbonara
 Python:
 
 ```
-pip install gerbonara
+pipx install gerbonara
 ```
 
-# Usage
+# Documentation and Examples
 
-Here's a simple example:
+Documentation can be found at:
 
-```python
-import gerbonara
-from gerbonara.render import GerberCairoContext
+https://gerbolyze.gitlab.io/gerbonara
 
-# Read gerber and Excellon files
-top_copper = gerbonara.read('example.GTL')
-nc_drill = gerbonara.read('example.txt')
+# Issues
 
-# Rendering context
-ctx = GerberCairoContext()
+Please file any bugs at our issue tracker:
 
-# Create SVG image
-top_copper.render(ctx)
-nc_drill.render(ctx, 'composite.svg')
-```
+https://gitlab.com/gerbolyze/gerbonara/-/issues
 
 ---
 

docs/cli.rst

@@ -0,0 +1,373 @@
+.. _cli-doc:
+
+Gerbonara's Command-Line Interface
+==================================
+
+Gerbonara comes with a built-in command-line interface that has functions for analyzing, rendering, modifying, and
+merging Gerber files.
+
+Invocation
+----------
+
+There are two ways to call gerbonara's command-line interface:
+
+.. :code:
+
+   $ gerbonara
+   $ python -m gerbonara
+
+For the first to work, make sure the installation's ``bin`` dir is in your ``$PATH``. If you installed gerbonara
+system-wide, that should be the case already, since the binary should end up in ``/usr/bin``. If you installed gerbonara
+using ``pip install --user``, make sure you have your user's ``~/.local/bin`` in your ``$PATH``.
+
+Commands and their usage
+------------------------
+
+.. code-block:: console
+
+    $ gerbonara --help
+    Usage: gerbonara [OPTIONS] COMMAND [ARGS]...
+
+      The gerbonara CLI allows you to analyze, render, modify and merge both
+      individual Gerber or Excellon files as well as sets of those files
+
+    Options:
+      --version
+      --help     Show this message and exit.
+
+    Commands:
+      bounding-box  Print the bounding box of a gerber file in "[x_min]...
+      layers        Read layers from a directory or zip with Gerber files and...
+      merge         Merge multiple single Gerber or Excellon files, or...
+      meta          Extract layer mapping and print it along with layer...
+      render        Render a gerber file, or a directory or zip of gerber...
+      rewrite       Parse a single gerber file, apply transformations, and...
+      transform     Transform all gerber files in a given directory or zip...
+
+Rendering
+~~~~~~~~~
+
+Gerbonara can render single Gerber (:py:class:`~.rs274x.GerberFile`) or Excellon (:py:class:`~.excellon.ExcellonFile`)
+layers, or whole board stacks (:py:class:`~.layers.LayerStack`) to SVG.
+
+``gerbonara render``
+********************
+.. program:: gerbonara render
+
+.. code-block:: console
+
+    $ gerbonara render [OPTIONS] INPATH [OUTFILE]
+
+``gerbonara render`` renders one or more Gerber or Excellon files as a single SVG file. It can read single files,
+directorys of files, and ZIP files. To read directories or zips, it applies gerbonara's layer filename matching rules.
+These built-in rules should work with common settings in a wide variety of CAD tools.
+
+.. option:: --warnings [default|ignore|once]
+
+    Enable or disable file format warnings during parsing (default: on)
+
+
+.. option:: -m, --input-map <json_file>
+
+   Extend or override layer name mapping with name map from JSON file. The JSON file must contain a single JSON dict
+   with an arbitrary number of string: string entries. The keys are interpreted as regexes applied to the filenames via
+   re.fullmatch, and each value must either be the string ``ignore`` to remove this layer from previous automatic guesses,
+   or a gerbonara layer name such as ``top copper``, ``inner_2 copper`` or ``bottom silk``.
+
+.. option:: --use-builtin-name-rules / --no-builtin-name-rules
+
+    Disable built-in layer name rules and use only rules given by :option:`--input-map`
+
+
+.. option:: --force-zip
+
+   Force treating input path as a zip file (default: guess file type from extension and contents)
+
+.. option:: --top, --bottom
+
+   Which side of the board to render
+
+.. option:: --command-line-units <metric|us-customary>
+
+    Units for values given in other options. Default: millimeter
+
+.. option:: --margin <float>
+
+   Add space around the board inside the viewport
+
+.. option:: --force-bounds <min_x,min_y,max_x,max_y>
+
+   Force SVG bounding box to the given value.
+
+.. option:: --inkscape, --standard-svg
+
+   Export in Inkscape SVG format with layers and stuff instead of plain SVG.
+
+.. option:: --colorscheme <json_file>
+
+    Load colorscheme from given JSON file. The JSON file must contain a single dict with keys ``copper``, ``silk``,
+    ``mask``, ``paste``, ``drill`` and ``outline``. Each key must map to a string containing either a normal 6-digit hex
+    color with leading hash sign, or an 8-digit hex color with leading hash sign, where the last two digits set the
+    layer's alpha value (opacity), with ``ff`` being completely opaque, and ``00`` being invisibly transparent.
+
+Modification
+~~~~~~~~~~~~
+
+``gerbonara rewrite``
+*********************
+
+.. program:: gerbonara rewrite
+
+.. code-block:: console
+   
+    gerbonara rewrite [OPTIONS] INFILE OUTFILE
+
+Parse a single gerber file, apply transformations, and re-serialize it into a new gerber file. Without transformations,
+this command can be used to convert a gerber file to use different settings (e.g. units, precision), but can also be
+used to "normalize" gerber files in a weird format into a more standards-compatible one as gerbonara's gerber parser is
+significantly more robust for weird inputs than others.
+
+.. option:: --warnings <default|ignore|once>
+
+   Enable or disable file format warnings during parsing (default: on)
+
+.. option:: -t, --transform <code>
+
+   Execute python transformation script on input. You have access to the functions ``translate(x, y)``,
+   ``scale(factor)`` and ``rotate(angle, center_x?, center_y?)``, the bounding box variables ``x_min``, ``y_min``,
+   ``x_max``, ``y_max``, ``width`` and ``height``, and everything from python's built-in math module (e.g. ``pi``,
+   ``sqrt``, ``sin``). As convenience methods, ``center()`` and ``origin()`` are provided to center the board
+   respectively move its bottom-left corner to the origin. Coordinates are given in ``--command-line-units``, angles in
+   degrees, and scale as a scale factor (as opposed to a percentage). Example: ``translate(-10, 0); rotate(45, 0, 5)``
+
+.. option:: --command-line-units <metric|us-customary>
+
+    Units for values given in other options. Default: millimeter
+
+.. option:: -n, --number-format <decimal.fractional>
+
+   Override number format to use during export in ``[integer digits].[decimal digits]`` notation, e.g. ``2.6``.
+
+.. option:: -u, --units <metric|us-customary>
+
+   Override export file units
+
+.. option:: -z, --zero-suppression <off|leading|trailing>
+
+   Override export zero suppression setting. Note: The meaning of this value is like in the Gerber spec for both Gerber
+   and Excellon files!
+
+.. option:: --keep-comments, --drop-comments
+
+   Keep gerber comments. Note: Comments will be prepended to the start of file, and will not occur in their old
+   position.
+
+.. option:: --default-settings, --reuse-input-settings
+
+   Use sensible defaults for the output file format settings (default) or use the same export settings as the input file
+   instead of sensible defaults.
+
+.. option:: --input-number-format <decimal.fractional>
+
+   Override number format of input file (mostly useful for Excellon files)
+
+.. option:: --input-units <metric|us-customary>
+
+   Override units of input file
+
+.. option:: --input-zero-suppression <off|leading|trailing>
+
+   Override zero suppression setting of input file
+
+
+``gerbonara transform``
+***********************
+
+.. program:: gerbonara transform
+
+.. code-block:: console
+
+    gerbonara transform [OPTIONS] TRANSFORM INPATH OUTPATH
+
+Transform all gerber files in a given directory or zip file using the given python transformation script.
+
+In the python transformation script you have access to the functions ``translate(x, y)``, ``scale(factor)`` and
+``rotate(angle, center_x?, center_y?)``, the bounding box variables ``x_min``, ``y_min``, ``x_max``, ``y_max``,
+``width`` and ``height``, and everything from python's built-in math module (e.g. ``pi``, ``sqrt``, ``sin``). As
+convenience methods, ``center()`` and ``origin()`` are provided to center the board resp. move its bottom-left corner to
+the origin. Coordinates are given in --command-line-units, angles in degrees, and scale as a scale factor (as opposed to
+a percentage). Example: ``translate(-10, 0); rotate(45, 0, 5)``
+
+.. option:: -m, --input-map <json_file>
+
+   Extend or override layer name mapping with name map from JSON file. The JSON file must contain a single JSON dict
+   with an arbitrary number of string: string entries. The keys are interpreted as regexes applied to the filenames via
+   re.fullmatch, and each value must either be the string ``ignore`` to remove this layer from previous automatic
+   guesses, or a gerbonara layer name such as ``top copper``, ``inner_2 copper`` or ``bottom silk``.
+
+.. option:: --use-builtin-name-rules, --no-builtin-name-rules
+
+    Disable built-in layer name rules and use only rules given by ``--input-map``
+
+.. option:: --warnings <default|ignore|once>
+
+   Enable or disable file format warnings during parsing (default: on)
+
+.. option:: --units <metric|us-customary>
+
+    Units for values given in other options. Default: millimeter
+
+.. option:: -n, --number-format <decimal.fractional>
+
+   Override number format to use during export in ``[integer digits].[decimal digits]`` notation, e.g. ``2.6``.
+
+.. option:: --default-settings, --reuse-input-settings
+
+   Use sensible defaults for the output file format settings (default) or use the same export settings as the input file
+   instead of sensible defaults.
+
+.. option:: --force-zip
+
+   Force treating input path as a zip file (default: guess file type from extension and contents)
+
+.. option:: --output-naming-scheme <altium|kicad>
+
+   Name output files according to the selected naming scheme instead of keeping the old file names.
+
+
+``gerbonara merge``
+*******************
+
+.. program:: gerbonara merge
+
+.. code-block:: console
+   
+    $ gerbonara merge [OPTIONS] [INPATH]... OUTPATH
+
+Merge multiple single Gerber or Excellon files, or multiple stacks of Gerber files, into one.
+
+.. note::
+   When used with only one input, this command *normalizes* the input, converting all files to a well-defined, widely
+   supported Gerber subset with sane settings. When a ``--output-naming-scheme`` is given, it additionally renames all
+   files to a standardized naming convention.
+
+.. option:: --command-line-units <metric|us-customary>
+
+    Units for values given in --transform. Default: millimeter
+
+.. option:: --warnings <default|ignore|once>
+
+   Enable or disable file format warnings during parsing (default: on)
+
+.. option:: --offset <COORDINATE>
+
+   Offset for the n'th file as a ``x,y`` string in unit given by ``--command-line-units`` (default: millimeter). Can be
+   given multiple times, and the first option affects the first input, the second option affects the second input, and
+   so on.
+
+.. option:: --rotation <ROTATION>
+
+   Rotation for the n'th file in degrees clockwise, optionally followed by comma- separated rotation center X and Y
+   coordinates. Can be given multiple times, and the first option affects the first input, the second option affects the
+   second input, and so on.
+
+.. option:: -m, --input-map <json_file>
+
+   Extend or override layer name mapping with name map from JSON file. This option can be given multiple times, in which
+   case the n'th option affects only the n'th input, like with ``--offset`` and ``--rotation``. The JSON file must
+   contain a single JSON dict with an arbitrary number of string: string entries. The keys are interpreted as regexes
+   applied to the filenames via re.fullmatch, and each value must either be the string "ignore" to remove this layer
+   from previous automatic guesses, or a gerbonara layer name such as ``top copper``, ``inner_2 copper`` or ``bottom
+   silk``.
+
+.. option:: --default-settings, --reuse-input-settings
+
+   Use sensible defaults for the output file format settings (default) or use the same export settings as the input file
+   instead of sensible defaults.
+
+.. option:: --output-naming-scheme <altium|kicad>
+
+   Name output files according to the selected naming scheme instead of keeping the old file names of the first input.
+
+.. option:: --output-board-name <TEXT>
+
+    Override board name used with ``--output-naming-scheme``
+
+.. option:: --use-builtin-name-rules, --no-builtin-name-rules
+    
+    Disable built-in layer name rules and use only rules given by --input-map
+
+File analysis
+~~~~~~~~~~~~~
+
+``gerbonara bounding-box``
+**************************
+
+.. program:: gerbonara bounding-box
+
+.. code-block:: console
+
+   gerbonara bounding-box [OPTIONS] INFILE
+
+Print the bounding box of a gerber file in ``[x_min] [y_min] [x_max] [y_max]`` format. The bounding box contains all
+graphic objects in this file, so e.g. a 100 mm by 100 mm square drawn with a 1mm width circular aperture will result in
+an 101 mm by 101 mm bounding box.
+
+.. option:: --warnings <default|ignore|once>
+
+    Enable or disable file format warnings during parsing (default: on)
+
+.. option:: --units <metric|us-customary>
+    
+    Output bounding box in this unit (default: millimeter)
+
+.. option:: --input-number-format <decimal.fractional>
+
+    Override number format of input file (mostly useful for Excellon files)
+    
+.. option:: --input-units <metric|us-customary>
+
+    Override units of input file
+
+.. option:: --input-zero-suppression <off|leading|trailing>
+
+    Override zero suppression setting of input file
+
+
+``gerbonara meta``
+******************
+.. program:: gerbonara meta
+
+.. code-block:: console
+
+    gerbonara meta [OPTIONS] PATH
+
+Read a board from a folder or zip, and print the found layer mapping along with layer metadata as JSON to stdout. A
+machine-readable variant of the :program:`gerbonara render` command. All lengths in the JSON are given in millimeter.
+
+.. option:: --warnings <default|ignore|once>
+
+   Enable or disable file format warnings during parsing (default: on)
+
+.. option:: --force-zip
+
+   Force treating input path as zip file (default: guess file type from extension and contents)
+
+
+``gerbonara layers``
+********************
+.. program:: gerbonara render
+
+.. code-block:: console
+
+    $ gerbonara layers [OPTIONS] PATH
+
+Prints a layer-by-layer description of the board found under the given path. The path can be a directory or zip file.
+
+.. option:: --warnings <default|ignore|once>
+
+   Enable or disable file format warnings during parsing (default: on)
+
+.. option:: --force-zip
+
+   Force treating input path as zip file (default: guess file type from extension and contents)

docs/conf.py

@@ -10,6 +10,12 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 
+import subprocess
+def get_version():
+    res = subprocess.run(['git', 'describe', '--tags', '--match', 'v*'], capture_output=True, check=True, text=True)
+    version, _, _rest = res.stdout.strip()[1:].partition('-')
+    return version
+
 from pathlib import Path
 import sys
 sys.path.insert(0, str(Path(__file__).parent.parent.absolute()))
@@ -21,7 +27,7 @@ copyright = '2022, Jan Götte'
 author = 'jaseg'
 
 # The full version, including alpha/beta/rc tags
-release = '0.9.0'
+release = get_version()
 
 
 # -- General configuration ---------------------------------------------------

docs/examples.rst

@@ -0,0 +1,64 @@
+.. _examples-doc:
+
+Examples
+========
+
+Solder mask rings
+-----------------
+
+This example script takes a board exported with a more recent KiCad version, and removes solder mask everywhere, but
+leaves a thin ring of solder mask around every pad. Might be useful for some artsy boards.
+
+.. image:: ex-mask-islands.png
+
+.. code-block:: python
+    from gerbonara import *
+    from shapely import *
+
+    stack = layers.LayerStack.open('gerber')
+    # Let's work in mm here. Gerbonara will take care to convert units when the file is in US customary units.
+    (x1, y1), (x2, y2) = stack.bounding_box(unit=utils.MM)
+
+    for l in [stack['bottom mask'], stack['top mask']]:
+
+        # The solder mask gerber layer by convention is "negative". That is, a "dark" polarity (drawn) Gerber primitive
+        # will result in an opening in the solder mask. Conversely, an empty gerber file would lead to the entire board
+        # being covered in solder mask.
+        #
+        # Here, we add a rectangle covering the entire board so the entire board is *free* of solder mask.
+
+        new = [graphic_objects.Region(
+            [(x1, y1), (x1, y2), (x2, y2), (x2, y1), (x1, y1)],
+            unit=utils.MM,
+            polarity_dark=True)]
+
+        # Iterate through all objects on the solder mask layer. In later KiCad versions, everything on the solder mask
+        # layer is exported as a Gerber region, which is a really bad idea, but makes things easy for us here.
+        for obj in l.objects:
+            if isinstance(obj, gerbonara.graphic_objects.Region):
+                regions = []
+            else:
+                regions = [gerbonara.graphic_objects.Region.from_arc_poly(prim.to_arc_poly())
+                    for prim in obj.to_primitives(unit=gerbonara.utils.MM)]
+
+            for obj in regions:
+                # Convert the region to a shapely line string
+                ls = LineString(obj.outline).normalize()
+
+                # Ask shapely to offset the line string by 1 mm
+                out = ls.offset_curve(obj.unit(1, 'mm'))
+
+                # For negative offsets, this operation can result in an object being split up into multiple parts, so we
+                # might get back a MultiLineString instead of a LineString.
+                for ls in (out.geoms if hasattr(out, 'geoms') else [out]):
+
+                    # Convert the resulting shapely object back to a Gerber region.
+                    new.append(graphic_objects.Region(
+                        unit=obj.unit,
+                        polarity_dark=not obj.polarity_dark,
+                        outline=list(ls.coords)))
+
+        # Append the new objects to the original layer data
+        l.objects = new + l.objects
+    # Write the modified layer stack to a new Gerber directory
+    stack.save_to_directory('output-gerbers')

docs/file-api.rst

@@ -12,10 +12,6 @@ syntactic hints, and can automatically match all files in a folder to their appr
 
 :py:class:`.CamFile` is the common base class for all layer types.
 
-
-.. autoclass:: gerbonara.layers.LayerStack
-   :members:
-
 .. autoclass:: gerbonara.cam.CamFile
    :members:
 
@@ -28,3 +24,6 @@ syntactic hints, and can automatically match all files in a folder to their appr
 .. autoclass:: gerbonara.ipc356.Netlist
    :members:
 
+.. autoclass:: gerbonara.layers.LayerStack
+   :members:
+

docs/index.rst

@@ -46,7 +46,9 @@ Features
     :maxdepth: 2
     :caption: Contents:
 
+    cli
     api-concepts
+    examples
     file-api
     object-api
     apertures
@@ -57,7 +59,36 @@ Features
 Quick Start
 ===========
 
+First, install gerbonara from PyPI using pip:
 
+.. code-block:: shell
+
+   pip install --user gerbonara
+
+Then, you are ready to read and write gerber files:
+
+.. code-block:: python
+
+    from gerbonara import LayerStack
+
+    stack = LayerStack.open('output/gerber')
+    w, h = stack.outline.size('mm')
+    print(f'Board size is {w:.1f} mm x {h:.1f} mm')
+
+You can find some more elaborate examples in this doc's :ref:`Examples section<examples-doc>`.
+
+Command-Line Interface
+======================
+
+Gerbonara comes with a :ref:`built-in command-line interface<cli-doc>` that has functions for analyzing, rendering,
+modifying, and merging Gerber files. To access it, use either the ``gerbonara`` command that is part of the python
+package, or run ``python -m gerbonara``. For a list of functions or help on their usage, you can use:
+
+.. code:: console
+
+   $ python -m gerbonara --help
+   [...]
+   $ python -m gerbonara render --help
 
 Development
 ===========
@@ -74,7 +105,11 @@ Our issue tracker is also on Gitlab:
 
 https://gitlab.com/gerbolyze/gerbonara/-/issues
 
-With Gebronara, we aim to support as many different format variants as possible. If you have a file that Gerbonara can't
+A copy of this documentation can also be found at gitlab:
+
+https://gerbolyze.gitlab.io/gerbonara/
+
+With Gerbonara, we aim to support as many different format variants as possible. If you have a file that Gerbonara can't
 open, please file an issue on our issue tracker. Even if Gerbonara can open all your files, for regression testing we
 are very interested in example files generated by any CAD or CAM tool that is not already on the list of supported
 tools.

examples/highlight_outline.py

@@ -10,7 +10,7 @@ from gerbonara.utils import MM
 from gerbonara.utils import rotate_point
 
 def highlight_outline(input_dir, output_dir):
-    stack = LayerStack.from_directory(input_dir)
+    stack = LayerStack.open(input_dir)
 
     outline = []
     for obj in stack.outline.objects:
@@ -28,7 +28,6 @@ def highlight_outline(input_dir, output_dir):
     marker_nx, marker_ny = math.sin(marker_angle), math.cos(marker_angle)
 
     ap = CircleAperture(0.1, unit=MM)
-    stack['top silk'].apertures.append(ap)
 
     for line in outline:
         cx, cy = (line.x1 + line.x2)/2, (line.y1 + line.y2)/2

examples/load_directory.py

@@ -7,5 +7,5 @@ if __name__ == '__main__':
     args = parser.parse_args()
 
     import gerbonara
-    print(gerbonara.LayerStack.from_directory(args.input))
+    print(gerbonara.LayerStack.open(args.input))
 

examples/test_arc_approx.py

@@ -2,6 +2,7 @@
 
 import math
 
+from gerbonara.utils import MM
 from gerbonara.graphic_objects import Arc
 from gerbonara.graphic_objects import rotate_point
 
@@ -22,7 +23,8 @@ def approx_test():
                     x1, y1 = rotate_point(0, -1, start_angle*eps)
                     x2, y2 = rotate_point(x1, y1, sweep_angle*eps*(-1 if clockwise else 1))
                     
-                    arc = Arc(x1+cx, y1+cy, x2+cx, y2+cy, -x1, -y1, clockwise=clockwise, aperture=None, polarity_dark=True)
+                    arc = Arc(x1+cx, y1+cy, x2+cx, y2+cy, -x1, -y1, clockwise=clockwise, aperture=None,
+                              polarity_dark=True, unit=MM)
                     lines = arc.approximate(max_error=max_error)
 
                     print(f'<path style="fill: {color}; stroke: none;" d="M {cx} {cy} L {lines[0].x1} {lines[0].y1}', end=' ')

gerbonara/__main__.py

@@ -1,122 +0,0 @@
-#! /usr/bin/env python
-# -*- coding: utf-8 -*-
-
-# Copyright 2013-2014 Paulo Henrique Silva <ph.silva@gmail.com>
-
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-
-#     http://www.apache.org/licenses/LICENSE-2.0
-
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations under
-# the License.
-
-import os
-import argparse
-from .render import available_renderers
-from .render import theme
-from .pcb import PCB
-from . import load_layer
-
-
-def main():
-    parser = argparse.ArgumentParser(
-        description='Render gerber files to image',
-        prog='gerber-render'
-    )
-    parser.add_argument(
-        'filenames', metavar='FILENAME', type=str, nargs='+',
-        help='Gerber files to render. If a directory is provided, it should '
-             'be provided alone and should contain the gerber files for a '
-             'single PCB.'
-    )
-    parser.add_argument(
-        '--outfile', '-o', type=str, nargs='?', default='out',
-        help="Output Filename (extension will be added automatically)"
-    )
-    parser.add_argument(
-        '--backend', '-b', choices=available_renderers.keys(), default='cairo',
-        help='Choose the backend to use to generate the output.'
-    )
-    parser.add_argument(
-        '--theme', '-t', choices=theme.THEMES.keys(), default='default',
-        help='Select render theme.'
-    )
-    parser.add_argument(
-        '--width', type=int, default=1920, help='Maximum width.'
-    )
-    parser.add_argument(
-        '--height', type=int, default=1080, help='Maximum height.'
-    )
-    parser.add_argument(
-        '--verbose', '-v', action='store_true', default=False,
-        help='Increase verbosity of the output.'
-    )
-    # parser.add_argument(
-    #     '--quick', '-q', action='store_true', default=False,
-    #     help='Skip longer running rendering steps to produce lower quality'
-    #          ' output faster. This only has an effect for the freecad backend.'
-    # )
-    # parser.add_argument(
-    #     '--nox', action='store_true', default=False,
-    #     help='Run without using any GUI elements. This may produce suboptimal'
-    #          'output. For the freecad backend, colors, transparancy, and '
-    #          'visibility cannot be set without a GUI instance.'
-    # )
-
-    args = parser.parse_args()
-
-    renderer = available_renderers[args.backend]()
-
-    if args.backend in ['cairo', ]:
-        outext = 'png'
-    else:
-        outext = None
-
-    if os.path.exists(args.filenames[0]) and os.path.isdir(args.filenames[0]):
-        directory = args.filenames[0]
-        pcb = PCB.from_directory(directory)
-
-        if args.backend in ['cairo', ]:
-            top = pcb.top_layers
-            bottom = pcb.bottom_layers
-            copper = pcb.copper_layers
-
-            outline = pcb.outline_layer
-            if outline:
-                top = [outline] + top
-                bottom = [outline] + bottom
-                copper = [outline] + copper + pcb.drill_layers
-
-            renderer.render_layers(
-                layers=top, theme=theme.THEMES[args.theme],
-                max_height=args.height, max_width=args.width,
-                filename='{0}.top.{1}'.format(args.outfile, outext)
-            )
-            renderer.render_layers(
-                layers=bottom, theme=theme.THEMES[args.theme],
-                max_height=args.height, max_width=args.width,
-                filename='{0}.bottom.{1}'.format(args.outfile, outext)
-            )
-            renderer.render_layers(
-                layers=copper, theme=theme.THEMES['Transparent Multilayer'],
-                max_height=args.height, max_width=args.width,
-                filename='{0}.copper.{1}'.format(args.outfile, outext))
-        else:
-            pass
-    else:
-        filenames = args.filenames
-        for filename in filenames:
-            layer = load_layer(filename)
-            settings = theme.THEMES[args.theme].get(layer.layer_class, None)
-            renderer.render_layer(layer, settings=settings)
-        renderer.dump(filename='{0}.{1}'.format(args.outfile, outext))
-
-
-if __name__ == '__main__':
-    main()
-

gerbonara/aperture_macros/expression.py

@@ -1,211 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-# Copyright 2021 Jan Götte <gerbonara@jaseg.de>
-
-import operator
-import re
-import ast
-
-from ..utils import MM, Inch, MILLIMETERS_PER_INCH
-
-
-def expr(obj):
-    return obj if isinstance(obj, Expression) else ConstantExpression(obj)
-
-
-class Expression:
-    def optimized(self, variable_binding={}):
-        return self
-
-    def __str__(self):
-        return f'<{self.to_gerber()}>'
-
-    def __repr__(self):
-        return f'<E {self.to_gerber()}>'
-
-    def converted(self, unit):
-        return self
-
-    def calculate(self, variable_binding={}, unit=None):
-        expr = self.converted(unit).optimized(variable_binding)
-        if not isinstance(expr, ConstantExpression):
-            raise IndexError(f'Cannot fully resolve expression due to unresolved variables: {expr} with variables {variable_binding}')
-        return expr.value
-
-    def __add__(self, other):
-        return OperatorExpression(operator.add, self, expr(other)).optimized()
-
-    def __radd__(self, other):
-        return expr(other) + self
-
-    def __sub__(self, other):
-        return OperatorExpression(operator.sub, self, expr(other)).optimized()
-
-    def __rsub__(self, other):
-        return expr(other) - self
-
-    def __mul__(self, other):
-        return OperatorExpression(operator.mul, self, expr(other)).optimized()
-
-    def __rmul__(self, other):
-        return expr(other) * self
-
-    def __truediv__(self, other):
-        return OperatorExpression(operator.truediv, self, expr(other)).optimized()
-
-    def __rtruediv__(self, other):
-        return expr(other) / self
-
-    def __neg__(self):
-        return 0 - self
-
-    def __pos__(self):
-        return self
-
-class UnitExpression(Expression):
-    def __init__(self, expr, unit):
-        self._expr = expr
-        self.unit = unit
-
-    def to_gerber(self, unit=None):
-        return self.converted(unit).optimized().to_gerber()
-
-    def __eq__(self, other):
-        return type(other) == type(self) and \
-            self.unit == other.unit and\
-            self._expr == other._expr
-
-    def __str__(self):
-        return f'<{self._expr.to_gerber()} {self.unit}>'
-
-    def __repr__(self):
-        return f'<UE {self._expr.to_gerber()} {self.unit}>'
-
-    def converted(self, unit):
-        if self.unit is None or unit is None or self.unit == unit:
-            return self._expr
-
-        elif MM == unit:
-            return self._expr * MILLIMETERS_PER_INCH
-
-        elif Inch == unit:
-            return self._expr / MILLIMETERS_PER_INCH
-
-        else:
-            raise ValueError(f'invalid unit {unit}, must be "inch" or "mm".')
-
-    def __add__(self, other):
-        if not isinstance(other, UnitExpression):
-            raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
-
-        if self.unit == other.unit or self.unit is None or other.unit is None:
-            return UnitExpression(self._expr + other._expr, self.unit)
-
-        if other.unit == 'mm': # -> and self.unit == 'inch'
-            return UnitExpression(self._expr + (other._expr / MILLIMETERS_PER_INCH), self.unit)
-        else: # other.unit == 'inch' and self.unit == 'mm'
-            return UnitExpression(self._expr + (other._expr * MILLIMETERS_PER_INCH), self.unit)
-
-    def __radd__(self, other):
-        # left hand side cannot have been an UnitExpression or __radd__ would not have been called
-        raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
-
-    def __sub__(self, other):
-        return (self + (-other)).optimize()
-
-    def __rsub__(self, other):
-        # see __radd__ above
-        raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
-
-    def __mul__(self, other):
-        return UnitExpression(self._expr * other, self.unit)
-
-    def __rmul__(self, other):
-        return UnitExpression(other * self._expr, self.unit)
-
-    def __truediv__(self, other):
-        return UnitExpression(self._expr / other, self.unit)
-
-    def __rtruediv__(self, other):
-        return UnitExpression(other / self._expr, self.unit)
-
-    def __neg__(self):
-        return UnitExpression(-self._expr, self.unit)
-
-    def __pos__(self):
-        return self
-
-
-class ConstantExpression(Expression):
-    def __init__(self, value):
-        self.value = value
-
-    def __float__(self):
-        return float(self.value)
-
-    def __eq__(self, other):
-        return type(self) == type(other) and self.value == other.value
-
-    def to_gerber(self, _unit=None):
-        return f'{self.value:.6f}'.rstrip('0').rstrip('.')
-
-    
-class VariableExpression(Expression):
-    def __init__(self, number):
-        self.number = number
-
-    def optimized(self, variable_binding={}):
-        if self.number in variable_binding:
-            return ConstantExpression(variable_binding[self.number])
-        return self
-
-    def __eq__(self, other):
-        return type(self) == type(other) and \
-                self.number == other.number
-
-    def to_gerber(self, _unit=None):
-        return f'${self.number}'
-
-
-class OperatorExpression(Expression):
-    def __init__(self, op, l, r):
-        self.op = op
-        self.l = ConstantExpression(l) if isinstance(l, (int, float)) else l
-        self.r = ConstantExpression(r) if isinstance(r, (int, float)) else r
-
-    def __eq__(self, other):
-        return type(self) == type(other) and \
-                self.op == other.op and \
-                self.l == other.l and \
-                self.r == other.r
-
-    def optimized(self, variable_binding={}):
-        l = self.l.optimized(variable_binding)
-        r = self.r.optimized(variable_binding)
-        
-        if self.op in (operator.add, operator.mul):
-            if id(r) < id(l):
-                l, r = r, l
-
-        if isinstance(l, ConstantExpression) and isinstance(r, ConstantExpression):
-            return ConstantExpression(self.op(float(l), float(r)))
-
-        return OperatorExpression(self.op, l, r)
-        
-    def to_gerber(self, unit=None):
-        lval = self.l.to_gerber(unit)
-        rval = self.r.to_gerber(unit)
-
-        if isinstance(self.l, OperatorExpression):
-            lval = f'({lval})'
-        if isinstance(self.r, OperatorExpression):
-            rval = f'({rval})'
-
-        op = {operator.add: '+',
-              operator.sub: '-',
-              operator.mul: 'X',
-              operator.truediv: '/'} [self.op]
-
-        return f'{lval}{op}{rval}'
-

gerbonara/aperture_macros/parse.py

@@ -1,182 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-# Copyright 2021 Jan Götte <gerbonara@jaseg.de>
-
-import operator
-import re
-import ast
-import copy
-import math
-
-from . import primitive as ap
-from .expression import *
-from ..utils import MM
-
-def rad_to_deg(x):
-    return (x / math.pi) * 180
-
-def _map_expression(node):
-    if isinstance(node, ast.Num):
-        return ConstantExpression(node.n)
-
-    elif isinstance(node, ast.BinOp):
-        op_map = {ast.Add: operator.add, ast.Sub: operator.sub, ast.Mult: operator.mul, ast.Div: operator.truediv}
-        return OperatorExpression(op_map[type(node.op)], _map_expression(node.left), _map_expression(node.right))
-
-    elif isinstance(node, ast.UnaryOp):
-        if type(node.op) == ast.UAdd:
-            return _map_expression(node.operand)
-        else:
-            return OperatorExpression(operator.sub, ConstantExpression(0), _map_expression(node.operand))
-
-    elif isinstance(node, ast.Name):
-        return VariableExpression(int(node.id[3:])) # node.id has format var[0-9]+
-
-    else:
-        raise SyntaxError('Invalid aperture macro expression')
-
-def _parse_expression(expr):
-    expr = expr.lower().replace('x', '*')
-    expr = re.sub(r'\$([0-9]+)', r'var\1', expr)
-    try:
-        parsed = ast.parse(expr, mode='eval').body
-    except SyntaxError as e:
-        raise SyntaxError('Invalid aperture macro expression') from e
-    return _map_expression(parsed)
-
-class ApertureMacro:
-    def __init__(self, name=None, primitives=None, variables=None):
-        self._name = name
-        self.comments = []
-        self.variables = variables or {}
-        self.primitives = primitives or []
-
-    @classmethod
-    def parse_macro(cls, name, body, unit):
-        macro = cls(name)
-
-        blocks = re.sub(r'\s', '', body).split('*')
-        for block in blocks:
-            if not (block := block.strip()): # empty block
-                continue
-
-            if block[0:1] == '0 ': # comment
-                macro.comments.append(Comment(block[2:]))
-            
-            if block[0] == '$': # variable definition
-                name, expr = block.partition('=')
-                number = int(name[1:])
-                if number in macro.variables:
-                    raise SyntaxError(f'Re-definition of aperture macro variable {number} inside macro')
-                macro.variables[number] = _parse_expression(expr)
-
-            else: # primitive
-                primitive, *args = block.split(',')
-                args = [ _parse_expression(arg) for arg in args ]
-                primitive = ap.PRIMITIVE_CLASSES[int(primitive)](unit=unit, args=args)
-                macro.primitives.append(primitive)
-
-        return macro
-
-    @property
-    def name(self):
-        if self._name is not None:
-            return self._name
-        else:
-            return f'gn_{hash(self)}'
-
-    @name.setter
-    def name(self, name):
-        self._name = name
-
-    def __str__(self):
-        return f'<Aperture macro {self.name}, variables {str(self.variables)}, primitives {self.primitives}>'
-
-    def __repr__(self):
-        return str(self)
-
-    def __eq__(self, other):
-        return hasattr(other, 'to_gerber') and self.to_gerber() == other.to_gerber()
-
-    def __hash__(self):
-        return hash(self.to_gerber())
-
-    def dilated(self, offset, unit=MM):
-        dup = copy.deepcopy(self)
-        new_primitives = []
-        for primitive in dup.primitives:
-            try:
-                if primitive.exposure.calculate():
-                    primitive.dilate(offset, unit)
-                    new_primitives.append(primitive)
-            except IndexError:
-                warnings.warn('Cannot dilate aperture macro primitive with exposure value computed from macro variable.')
-                pass
-        dup.primitives = new_primitives
-        return dup
-
-    def to_gerber(self, unit=None):
-        comments = [ c.to_gerber() for c in self.comments ]
-        variable_defs = [ f'${var.to_gerber(unit)}={expr}' for var, expr in self.variables.items() ]
-        primitive_defs = [ prim.to_gerber(unit) for prim in self.primitives ]
-        return '*\n'.join(comments + variable_defs + primitive_defs)
-
-    def to_graphic_primitives(self, offset, rotation, parameters : [float], unit=None, polarity_dark=True):
-        variables = dict(self.variables)
-        for number, value in enumerate(parameters, start=1):
-            if number in variables:
-                raise SyntaxError(f'Re-definition of aperture macro variable {i} through parameter {value}')
-            variables[number] = value
-
-        for primitive in self.primitives:
-            yield from primitive.to_graphic_primitives(offset, rotation, variables, unit, polarity_dark)
-
-    def rotated(self, angle):
-        dup = copy.deepcopy(self)
-        for primitive in dup.primitives:
-            # aperture macro primitives use degree counter-clockwise, our API uses radians clockwise
-            primitive.rotation -= rad_to_deg(angle)
-        return dup
-
-
-var = VariableExpression
-deg_per_rad = 180 / math.pi
-
-class GenericMacros:
-
-    _generic_hole = lambda n: [
-            ap.Circle('mm', [0, var(n), 0, 0]),
-            ap.CenterLine('mm', [0, var(n), var(n+1), 0, 0, var(n+2) * -deg_per_rad])]
-
-    # NOTE: All generic macros have rotation values specified in **clockwise radians** like the rest of the user-facing
-    # API.
-    circle = ApertureMacro('GNC', [
-        ap.Circle('mm', [1, var(1), 0, 0, var(4) * -deg_per_rad]),
-        *_generic_hole(2)])
-
-    rect = ApertureMacro('GNR', [
-        ap.CenterLine('mm', [1, var(1), var(2), 0, 0, var(5) * -deg_per_rad]),
-        *_generic_hole(3) ])
-
-    # w must be larger than h
-    obround = ApertureMacro('GNO', [
-        ap.CenterLine('mm', [1, var(1), var(2), 0, 0, var(5) * -deg_per_rad]),
-        ap.Circle('mm', [1, var(2), +var(1)/2, 0, var(5) * -deg_per_rad]),
-        ap.Circle('mm', [1, var(2), -var(1)/2, 0, var(5) * -deg_per_rad]),
-        *_generic_hole(3) ])
-
-    polygon = ApertureMacro('GNP', [
-        ap.Polygon('mm', [1, var(2), 0, 0, var(1), var(3) * -deg_per_rad]),
-        ap.Circle('mm', [0, var(4), 0, 0])])
-
-
-if __name__ == '__main__':
-    import sys
-    #for line in sys.stdin:
-        #expr = _parse_expression(line.strip())
-        #print(expr, '->', expr.optimized())
-
-    for primitive in parse_macro(sys.stdin.read(), 'mm'):
-        print(primitive)
-

gerbonara/aperture_macros/primitive.py

@@ -1,270 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-# Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
-# Copyright 2022 Jan Götte <gerbonara@jaseg.de>
-
-import warnings
-import contextlib
-import math
-
-from .expression import Expression, UnitExpression, ConstantExpression, expr
-
-from .. import graphic_primitives as gp
-
-
-def point_distance(a, b):
-    x1, y1 = a
-    x2, y2 = b
-    return math.sqrt((x2 - x1)**2 + (y2 - y1)**2)
-
-def deg_to_rad(a):
-    return (a / 180) * math.pi
-
-class Primitive:
-    def __init__(self, unit, args):
-        self.unit = unit
-
-        if len(args) > len(type(self).__annotations__):
-            raise ValueError(f'Too many arguments ({len(args)}) for aperture macro primitive {self.code} ({type(self)})')
-
-        for arg, (name, fieldtype) in zip(args, type(self).__annotations__.items()):
-            arg = expr(arg) # convert int/float to Expression object
-
-            if fieldtype == UnitExpression:
-                setattr(self, name, UnitExpression(arg, unit))
-            else:
-                setattr(self, name, arg)
-
-        for name in type(self).__annotations__:
-            if not hasattr(self, name):
-                raise ValueError(f'Too few arguments ({len(args)}) for aperture macro primitive {self.code} ({type(self)})')
-
-    def to_gerber(self, unit=None):
-        return f'{self.code},' + ','.join(
-                getattr(self, name).to_gerber(unit) for name in type(self).__annotations__)
-
-    def __str__(self):
-        attrs = ','.join(str(getattr(self, name)).strip('<>') for name in type(self).__annotations__)
-        return f'<{type(self).__name__} {attrs}>'
-
-    def __repr__(self):
-        return str(self)
-
-    class Calculator:
-        def __init__(self, instance, variable_binding={}, unit=None):
-            self.instance = instance
-            self.variable_binding = variable_binding
-            self.unit = unit
-
-        def __enter__(self):
-            return self
-
-        def __exit__(self, _type, _value, _traceback):
-            pass
-
-        def __getattr__(self, name):
-            return getattr(self.instance, name).calculate(self.variable_binding, self.unit)
-
-        def __call__(self, expr):
-            return expr.calculate(self.variable_binding, self.unit)
-
-
-class Circle(Primitive):
-    code = 1
-    exposure : Expression
-    diameter : UnitExpression
-    # center x/y
-    x : UnitExpression
-    y : UnitExpression
-    rotation : Expression = None
-
-    def __init__(self, unit, args):
-        super().__init__(unit, args)
-        if self.rotation is None:
-            self.rotation = ConstantExpression(0)
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            x, y = gp.rotate_point(calc.x, calc.y, deg_to_rad(calc.rotation) + rotation, 0, 0)
-            x, y = x+offset[0], y+offset[1]
-            return [ gp.Circle(x, y, calc.diameter/2, polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
-
-    def dilate(self, offset, unit):
-        self.diameter += UnitExpression(offset, unit)
-
-class VectorLine(Primitive):
-    code = 20
-    exposure : Expression
-    width : UnitExpression
-    start_x : UnitExpression
-    start_y : UnitExpression
-    end_x : UnitExpression
-    end_y : UnitExpression
-    rotation : Expression
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            center_x = (calc.end_x + calc.start_x) / 2
-            center_y = (calc.end_y + calc.start_y) / 2
-            delta_x = calc.end_x - calc.start_x
-            delta_y = calc.end_y - calc.start_y
-            length = point_distance((calc.start_x, calc.start_y), (calc.end_x, calc.end_y))
-
-            center_x, center_y = center_x+offset[0], center_y+offset[1]
-            rotation += deg_to_rad(calc.rotation) + math.atan2(delta_y, delta_x)
-
-            return [ gp.Rectangle(center_x, center_y, length, calc.width, rotation=rotation,
-                        polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
-
-    def dilate(self, offset, unit):
-        self.width += UnitExpression(2*offset, unit)
-
-
-class CenterLine(Primitive):
-    code = 21
-    exposure : Expression
-    width : UnitExpression
-    height : UnitExpression
-    # center x/y
-    x : UnitExpression
-    y : UnitExpression
-    rotation : Expression
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            rotation += deg_to_rad(calc.rotation)
-            x, y = gp.rotate_point(calc.x, calc.y, rotation, 0, 0)
-            x, y = x+offset[0], y+offset[1]
-            w, h = calc.width, calc.height
-
-            return [ gp.Rectangle(x, y, w, h, rotation, polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
-
-    def dilate(self, offset, unit):
-        self.width += UnitExpression(2*offset, unit)
-            
-
-class Polygon(Primitive):
-    code = 5
-    exposure : Expression
-    n_vertices : Expression
-    # center x/y
-    x : UnitExpression
-    y : UnitExpression
-    diameter : UnitExpression
-    rotation : Expression
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            rotation += deg_to_rad(calc.rotation)
-            x, y = gp.rotate_point(calc.x, calc.y, rotation, 0, 0)
-            x, y = x+offset[0], y+offset[1]
-            return [ gp.ArcPoly.from_regular_polygon(calc.x, calc.y, calc.diameter/2, calc.n_vertices, rotation,
-                        polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
-
-    def dilate(self, offset, unit):
-        self.diameter += UnitExpression(2*offset, unit)
-
-
-class Thermal(Primitive):
-    code = 7
-    exposure : Expression
-    # center x/y
-    x : UnitExpression
-    y : UnitExpression
-    d_outer : UnitExpression
-    d_inner : UnitExpression
-    gap_w : UnitExpression
-    rotation : Expression
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            rotation += deg_to_rad(calc.rotation)
-            x, y = gp.rotate_point(calc.x, calc.y, rotation, 0, 0)
-            x, y = x+offset[0], y+offset[1]
-
-            dark = (bool(calc.exposure) == polarity_dark)
-
-            return [
-                    gp.Circle(x, y, calc.d_outer/2, polarity_dark=dark),
-                    gp.Circle(x, y, calc.d_inner/2, polarity_dark=not dark),
-                    gp.Rectangle(x, y, d_outer, gap_w, rotation=rotation, polarity_dark=not dark),
-                    gp.Rectangle(x, y, gap_w, d_outer, rotation=rotation, polarity_dark=not dark),
-                    ]
-
-    def dilate(self, offset, unit):
-        # I'd rather print a warning and produce graphically slightly incorrect output in these few cases here than
-        # producing macros that may evaluate to primitives with negative values.
-        warnings.warn('Attempted dilation of macro aperture thermal primitive. This is not supported.')
-
-
-class Outline(Primitive):
-    code = 4
-
-    def __init__(self, unit, args):
-        if len(args) < 11:
-            raise ValueError(f'Invalid aperture macro outline primitive, not enough parameters ({len(args)}).')
-        if len(args) > 5004:
-            raise ValueError(f'Invalid aperture macro outline primitive, too many points ({len(args)//2-2}).')
-
-        self.exposure = args.pop(0)
-
-        # length arg must not contain variables (that would not make sense)
-        length_arg = args.pop(0).calculate()
-
-        if length_arg != len(args)//2-1:
-            raise ValueError(f'Invalid aperture macro outline primitive, given size {length_arg} does not match length of coordinate list({len(args)//2-1}).')
-
-        if len(args) % 2 == 1:
-            self.rotation = args.pop()
-        else:
-            self.rotation = ConstantExpression(0.0)
-
-        if args[0] != args[-2] or args[1] != args[-1]:
-            raise ValueError(f'Invalid aperture macro outline primitive, polygon is not closed {args[2:4], args[-3:-1]}')
-
-        self.coords = [(UnitExpression(x, unit), UnitExpression(y, unit)) for x, y in zip(args[0::2], args[1::2])]
-
-    def __str__(self):
-        return f'<Outline {len(self.coords)} points>'
-
-    def to_gerber(self, unit=None):
-        coords = ','.join(coord.to_gerber(unit) for xy in self.coords for coord in xy)
-        return f'{self.code},{self.exposure.to_gerber()},{len(self.coords)-1},{coords},{self.rotation.to_gerber()}'
-
-    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
-        with self.Calculator(self, variable_binding, unit) as calc:
-            rotation += deg_to_rad(calc.rotation)
-            bound_coords = [ gp.rotate_point(calc(x), calc(y), rotation, 0, 0) for x, y in self.coords ]
-            bound_coords = [ (x+offset[0], y+offset[1]) for x, y in bound_coords ]
-            bound_radii = [None] * len(bound_coords)
-            return [gp.ArcPoly(bound_coords, bound_radii, polarity_dark=(bool(calc.exposure) == polarity_dark))]
-
-    def dilate(self, offset, unit):
-        # we would need a whole polygon offset/clipping library here
-        warnings.warn('Attempted dilation of macro aperture outline primitive. This is not supported.')
-
-
-class Comment:
-    code = 0
-
-    def __init__(self, comment):
-        self.comment = comment
-
-    def to_gerber(self, unit=None):
-        return f'0 {self.comment}'
-
-PRIMITIVE_CLASSES = {
-    **{cls.code: cls for cls in [
-        Comment,
-        Circle,
-        VectorLine,
-        CenterLine,
-        Outline,
-        Polygon,
-        Thermal,
-    ]},
-    # alternative codes
-    2: VectorLine,
-}
-

gerbonara/excellon_settings.py

@@ -1,105 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-from argparse import PARSER
-
-# Copyright 2015 Garret Fick <garret@ficksworkshop.com>
-
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-
-#     http://www.apache.org/licenses/LICENSE-2.0
-
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""
-Excellon Settings Definition File module
-====================
-**Excellon file classes**
-
-This module provides Excellon file classes and parsing utilities
-"""
-
-import re
-try:
-    from cStringIO import StringIO
-except(ImportError):
-    from io import StringIO
-    
-from .cam import FileSettings
-    
-def loads(data):
-    """ Read settings file information and return an FileSettings
-    Parameters
-    ----------
-    data : string
-        string containing Excellon settings file contents
-
-    Returns
-    -------
-    file settings: FileSettings
-
-    """
-    
-    return ExcellonSettingsParser().parse_raw(data)
-
-def map_coordinates(value):
-    if value == 'ABSOLUTE':
-        return 'absolute'
-    return 'relative'
-
-def map_units(value):
-    if value == 'ENGLISH':
-        return 'inch'
-    return 'metric'
-
-def map_boolean(value):
-    return value == 'YES'
-
-SETTINGS_KEYS = {
-              'INTEGER-PLACES': (int, 'format-int'),
-              'DECIMAL-PLACES': (int, 'format-dec'),
-              'COORDINATES': (map_coordinates, 'notation'),
-              'OUTPUT-UNITS': (map_units, 'units'),
-              }
-
-class ExcellonSettingsParser(object):
-    """Excellon Settings PARSER
-    
-    Parameters
-    ----------
-    None
-    """
-    
-    def __init__(self):
-        self.values = {}
-        self.settings = None
-    
-    def parse_raw(self, data):
-        for line in StringIO(data):
-            self._parse(line.strip())
-            
-        # Create the FileSettings object
-        self.settings = FileSettings(
-                                     notation=self.values['notation'],
-                                     units=self.values['units'],
-                                     format=(self.values['format-int'], self.values['format-dec'])
-                                     )
-        
-        return self.settings
-            
-    def _parse(self, line):
-        
-        line_items = line.split()
-        if len(line_items) == 2:
-            
-            item_type_info = SETTINGS_KEYS.get(line_items[0])
-            if item_type_info:
-                # Convert the value to the expected type
-                item_value = item_type_info[0](line_items[1])
-                
-                self.values[item_type_info[1]] = item_value

gerbonara/graphic_primitives.py

@@ -1,259 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-#
-# Copyright 2022 Jan Götte <code@jaseg.de>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-import math
-import itertools
-
-from dataclasses import dataclass, KW_ONLY, replace
-
-from .utils import *
-
-
-@dataclass
-class GraphicPrimitive:
-    _ : KW_ONLY
-    polarity_dark : bool = True
-
-    def bounding_box(self):
-        """ Return the axis-aligned bounding box of this feature.
-
-        :returns: ``((min_x, min_Y), (max_x, max_y))``
-        :rtype: tuple
-        """
-
-        raise NotImplementedError()
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        """ Render this primitive into its SVG representation.
-
-        :param str fg: Foreground color. Must be an SVG color name.
-        :param str bg: Background color. Must be an SVG color name.
-        :param function tag: Tag constructor to use.
-
-        :rtype: str
-        """
-
-        raise NotImplementedError()
-
-
-@dataclass
-class Circle(GraphicPrimitive):
-    #: Center X coordinate
-    x : float
-    #: Center y coordinate
-    y : float
-    #: Radius, not diameter like in :py:class:`.apertures.CircleAperture`
-    r : float # Here, we use radius as common in modern computer graphics, not diameter as gerber uses.
-
-    def bounding_box(self):
-        return ((self.x-self.r, self.y-self.r), (self.x+self.r, self.y+self.r))
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        color = fg if self.polarity_dark else bg
-        return tag('circle', cx=self.x, cy=self.y, r=self.r, style=f'fill: {color}')
-
-
-@dataclass
-class ArcPoly(GraphicPrimitive):
-    """ Polygon whose sides may be either straight lines or circular arcs. """
-
-    #: list of (x : float, y : float) tuples. Describes closed outline, i.e. the first and last point are considered
-    #: connected.
-    outline : list
-    #: Must be either None (all segments are straight lines) or same length as outline.
-    #: Straight line segments have None entry.
-    arc_centers : list = None
-
-    @property
-    def segments(self):
-        """ Return an iterator through all *segments* of this polygon. For each outline segment (line or arc), this
-        iterator will yield a ``(p1, p2, center)`` tuple. If the segment is a straight line, ``center`` will be
-        ``None``.
-        """
-        ol = self.outline
-        return itertools.zip_longest(ol, ol[1:] + [ol[0]], self.arc_centers or [])
-
-    def bounding_box(self):
-        bbox = (None, None), (None, None)
-        for (x1, y1), (x2, y2), arc in self.segments:
-            if arc:
-                clockwise, (cx, cy) = arc
-                bbox = add_bounds(bbox, arc_bounds(x1, y1, x2, y2, cx, cy, clockwise))
-
-            else:
-                line_bounds = (min(x1, x2), min(y1, y2)), (max(x1, x2), max(y1, y2))
-                bbox = add_bounds(bbox, line_bounds)
-        return bbox
-
-    @classmethod
-    def from_regular_polygon(kls, x:float, y:float, r:float, n:int, rotation:float=0, polarity_dark:bool=True):
-        """ Convert an n-sided gerber polygon to a normal ArcPoly defined by outline """
-
-        delta = 2*math.pi / n
-
-        return kls([
-                (x + math.cos(rotation + i*delta) * r,
-                 y + math.sin(rotation + i*delta) * r)
-                for i in range(n) ], polarity_dark=polarity_dark)
-
-    def __len__(self):
-        """ Return the number of points on this polygon's outline (which is also the number of segments because the
-        polygon is closed). """
-        return len(self.outline)
-
-    def __bool__(self):
-        """ Return ``True`` if this polygon has any outline points. """
-        return bool(len(self))
-
-    def _path_d(self):
-        if len(self.outline) == 0:
-            return
-
-        yield f'M {self.outline[0][0]:.6} {self.outline[0][1]:.6}'
-
-        for old, new, arc in self.segments:
-            if not arc:
-                yield f'L {new[0]:.6} {new[1]:.6}'
-            else:
-                clockwise, center = arc
-                yield svg_arc(old, new, center, clockwise)
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        color = fg if self.polarity_dark else bg
-        return tag('path', d=' '.join(self._path_d()), style=f'fill: {color}')
-
-
-@dataclass
-class Line(GraphicPrimitive):
-    """ Straight line with round end caps. """
-    #: Start X coordinate. As usual in modern graphics APIs, this is at the center of the half-circle capping off this
-    #: line.
-    x1 : float
-    #: Start Y coordinate
-    y1 : float
-    #: End X coordinate
-    x2 : float
-    #: End Y coordinate
-    y2 : float
-    #: Line width
-    width : float
-
-    @classmethod
-    def from_obround(kls, x:float, y:float, w:float, h:float, rotation:float=0, polarity_dark:bool=True):
-        """ Convert a gerber obround into a :py:class:`~.graphic_primitives.Line`. """
-        if w > h:
-            w, a, b = h, w-h, 0
-        else:
-            w, a, b = w, 0, h-w
-
-        return kls(
-                *rotate_point(x-a/2, y-b/2, rotation, x, y),
-                *rotate_point(x+a/2, y+b/2, rotation, x, y),
-                w, polarity_dark=polarity_dark)
-
-    def bounding_box(self):
-        r = self.width / 2
-        return add_bounds(Circle(self.x1, self.y1, r).bounding_box(), Circle(self.x2, self.y2, r).bounding_box())
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        color = fg if self.polarity_dark else bg
-        width = f'{self.width:.6}' if not math.isclose(self.width, 0) else '0.01mm'
-        return tag('path', d=f'M {self.x1:.6} {self.y1:.6} L {self.x2:.6} {self.y2:.6}',
-                style=f'fill: none; stroke: {color}; stroke-width: {width}; stroke-linecap: round')
-
-@dataclass
-class Arc(GraphicPrimitive):
-    """ Circular arc with line width ``width`` going from ``(x1, y1)`` to ``(x2, y2)`` around center at ``(cx, cy)``. """
-    #: Start X coodinate
-    x1 : float
-    #: Start Y coodinate
-    y1 : float
-    #: End X coodinate
-    x2 : float
-    #: End Y coodinate
-    y2 : float
-    #: Center X coordinate relative to ``x1``
-    cx : float
-    #: Center Y coordinate relative to ``y1``
-    cy : float
-    #: ``True`` if this arc is clockwise from start to end. Selects between the large arc and the small arc given this
-    #: start, end and center
-    clockwise : bool
-    #: Line width of this arc.
-    width : float
-
-    def bounding_box(self):
-        r = self.width/2
-        endpoints = add_bounds(Circle(self.x1, self.y1, r).bounding_box(), Circle(self.x2, self.y2, r).bounding_box())
-
-        arc_r = math.dist((self.cx, self.cy), (self.x1, self.y1))
-
-        # extend C -> P1 line by line width / 2 along radius
-        dx, dy = self.x1 - self.cx, self.y1 - self.cy
-        x1 = self.x1 + dx/arc_r * r
-        y1 = self.y1 + dy/arc_r * r
-
-        # same for C -> P2
-        dx, dy = self.x2 - self.cx, self.y2 - self.cy
-        x2 = self.x2 + dx/arc_r * r
-        y2 = self.y2 + dy/arc_r * r
-
-        arc = arc_bounds(x1, y1, x2, y2, self.cx, self.cy, self.clockwise)
-        return add_bounds(endpoints, arc) # FIXME add "include_center" switch
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        color = fg if self.polarity_dark else bg
-        arc = svg_arc((self.x1, self.y1), (self.x2, self.y2), (self.cx, self.cy), self.clockwise)
-        width = f'{self.width:.6}' if not math.isclose(self.width, 0) else '0.01mm'
-        return tag('path', d=f'M {self.x1:.6} {self.y1:.6} {arc}',
-                style=f'fill: none; stroke: {color}; stroke-width: {width}; stroke-linecap: round; fill: none')
-
-@dataclass
-class Rectangle(GraphicPrimitive):
-    #: **Center** X coordinate
-    x : float
-    #: **Center** Y coordinate
-    y : float
-    #: width
-    w : float
-    #: height
-    h : float
-    #: rotation around center in radians
-    rotation : float
-
-    def bounding_box(self):
-        return self.to_arc_poly().bounding_box()
-
-    def to_arc_poly(self):
-        sin, cos = math.sin(self.rotation), math.cos(self.rotation)
-        sw, cw = sin*self.w/2, cos*self.w/2
-        sh, ch = sin*self.h/2, cos*self.h/2
-        x, y = self.x, self.y
-        return ArcPoly([
-            (x - (cw+sh), y - (ch+sw)),
-            (x - (cw+sh), y + (ch+sw)),
-            (x + (cw+sh), y + (ch+sw)),
-            (x + (cw+sh), y - (ch+sw)),
-            ])
-
-    def to_svg(self, fg='black', bg='white', tag=Tag):
-        color = fg if self.polarity_dark else bg
-        x, y = self.x - self.w/2, self.y - self.h/2
-        return tag('rect', x=x, y=y, width=self.w, height=self.h,
-                transform=svg_rotation(self.rotation, self.x, self.y), style=f'fill: {color}')
-

gerbonara/layers.py

@@ -1,584 +0,0 @@
-#! /usr/bin/env python
-# -*- coding: utf-8 -*-
-#
-# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
-# Copyright 2022 Jan Götte <code@jaseg.de>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-import os
-import re
-import warnings
-import copy
-from collections import namedtuple
-from pathlib import Path
-
-from .excellon import ExcellonFile, parse_allegro_ncparam, parse_allegro_logfile
-from .rs274x import GerberFile
-from .ipc356 import Netlist
-from .cam import FileSettings
-from .layer_rules import MATCH_RULES
-
-
-STANDARD_LAYERS = [
-        'mechanical outline',
-        'top copper',
-        'top mask',
-        'top silk',
-        'top paste',
-        'bottom copper',
-        'bottom mask',
-        'bottom silk',
-        'bottom paste',
-        ]
-
-class NamingScheme:
-    kicad = {
-    'top copper':           '{board_name}-F.Cu.gbr',
-    'top mask':             '{board_name}-F.Mask.gbr',
-    'top silk':             '{board_name}-F.SilkS.gbr',
-    'top paste':            '{board_name}-F.Paste.gbr',
-    'bottom copper':        '{board_name}-B.Cu.gbr',
-    'bottom mask':          '{board_name}-B.Mask.gbr',
-    'bottom silk':          '{board_name}-B.SilkS.gbr',
-    'bottom paste':         '{board_name}-B.Paste.gbr',
-    'inner copper':         '{board_name}-In{layer_number}.Cu.gbr',
-    'mechanical outline':   '{board_name}-Edge.Cuts.gbr',
-    'drill unknown':        '{board_name}.drl',
-    'other netlist':        '{board_name}.d356',
-    }
-
-
-def match_files(filenames):
-    matches = {}
-    for generator, rules in MATCH_RULES.items():
-        gen = {}
-        matches[generator] = gen
-        for layer, regex in rules.items():
-            for fn in filenames:
-                if (m := re.fullmatch(regex, fn.name, re.IGNORECASE)):
-                    if layer == 'inner copper':
-                        target = 'inner_' + ''.join(e or '' for e in m.groups()) + ' copper'
-                    else:
-                        target = layer
-                    gen[target] = gen.get(target, []) + [fn]
-    return matches
-
-
-def best_match(filenames):
-    matches = match_files(filenames)
-    matches = sorted(matches.items(), key=lambda pair: len(pair[1]))
-    generator, files = matches[-1]
-    return generator, files
-
-
-def identify_file(data):
-    if 'M48' in data:
-        return 'excellon'
-
-    if 'G90' in data and ';LEADER:' in data: # yet another allegro special case
-        return 'excellon'
-
-    if 'FSLAX' in data or 'FSTAX' in data:
-        return 'gerber'
-
-    if 'UNITS CUST' in data:
-        return 'ipc356'
-
-    return None
-
-
-def common_prefix(l):
-    out = []
-    for cand in l:
-        score = lambda n: sum(elem.startswith(cand[:n]) for elem in l)
-        baseline = score(1)
-        if len(l) - baseline > 5:
-            continue
-        for n in range(2, len(cand)):
-            if len(l) - score(n) > 5:
-                break
-        out.append(cand[:n-1])
- 
-    if not out:
-        return ''
- 
-    return sorted(out, key=len)[-1]
-
-def autoguess(filenames):
-    prefix = common_prefix([f.name for f in filenames])
-
-    matches = {}
-    for f in filenames:
-        name = layername_autoguesser(f.name[len(prefix):] if f.name.startswith(prefix) else f.name)
-        if name != 'unknown unknown':
-            matches[name] = matches.get(name, []) + [f]
-
-    inner_layers = [ m for m in matches if 'inner' in m ]
-    if len(inner_layers) >= 2 and 'copper top' not in matches and 'copper bottom' not in matches:
-        if 'inner_01 copper' in matches:
-            warnings.warn('Could not find copper layer. Re-assigning outermost inner layers to top/bottom copper.')
-            matches['top copper'] = matches.pop('inner_01 copper')
-            last_inner = sorted(inner_layers, key=lambda name: int(name.partition(' ')[0].partition('_')[2]))[-1]
-            matches['bottom copper'] = matches.pop(last_inner)
-
-    return matches
-
-
-def layername_autoguesser(fn):
-    fn, _, ext = fn.lower().rpartition('.')
-    
-    if ext in ('log', 'err', 'fdl', 'py', 'sh', 'md', 'rst', 'zip', 'pdf', 'svg', 'ps', 'png', 'jpg', 'bmp'):
-        return 'unknown unknown'
-
-    side, use = 'unknown', 'unknown'
-    if re.search('top|front|pri?m?(ary)?', fn):
-        side = 'top'
-        use = 'copper'
-
-    if re.search('bot(tom)?|back|sec(ondary)?', fn):
-        side = 'bottom'
-        use = 'copper'
-
-    if re.search('silks?(creen)?|symbol', fn):
-        use = 'silk'
-
-    elif re.search('(solder)?paste|metalmask', fn):
-        use = 'paste'
-
-    elif re.search('(solder)?(mask|resist)', fn):
-        use = 'mask'
-
-    elif re.search('drill|rout?e?', fn):
-        use = 'drill'
-        side = 'unknown'
-
-        if re.search(r'np(th|lt)?|(non|un)\W*plated|(non|un)\Wgalv', fn):
-            side = 'nonplated'
-
-        elif re.search('pth|plated|galv|plt', fn):
-            side = 'plated'
-
-    elif (m := re.search(r'(la?y?e?r?|in(ner)?|conduct(or|ive)?)\W*(?P<num>[0-9]+)', fn)):
-        use = 'copper'
-        side = f'inner_{int(m["num"]):02d}'
-
-    elif re.search('film', fn):
-        use = 'copper'
-
-    elif re.search('out(line)?', fn):
-        use = 'outline'
-        side = 'mechanical'
-
-    elif 'ipc' in fn and '356' in fn:
-        use = 'netlist'
-        side = 'other'
-
-    elif 'netlist' in fn:
-        use = 'netlist'
-        side = 'other'
-
-    if side == 'unknown':
-        if re.search(r'[^a-z0-9]a', fn):
-            side = 'top'
-        elif re.search(r'[^a-z0-9]b', fn):
-            side = 'bottom'
-
-    return f'{side} {use}'
-
-
-class LayerStack:
-
-    def __init__(self, graphic_layers, drill_layers, netlist=None, board_name=None):
-        self.graphic_layers = graphic_layers
-        self.drill_layers = drill_layers
-        self.board_name = board_name
-        self.netlist = netlist
-
-    @classmethod
-    def from_directory(kls, directory, board_name=None):
-
-        directory = Path(directory)
-        if not directory.is_dir():
-            raise FileNotFoundError(f'{directory} is not a directory')
-
-        files = [ path for path in directory.glob('**/*') if path.is_file() ]
-        generator, filemap = best_match(files)
-
-        if sum(len(files) for files in filemap.values()) < 6:
-            warnings.warn('Ambiguous gerber filenames. Trying last-resort autoguesser.')
-            generator = None
-            filemap = autoguess(files)
-            if len(filemap) < 6:
-                raise ValueError('Cannot figure out gerber file mapping. Partial map is: ', filemap)
-
-        excellon_settings, external_tools = None, None
-        if generator == 'geda':
-            # geda is written by geniuses who waste no bytes of unnecessary output so it doesn't actually include the
-            # number format in files that use imperial units. Unfortunately it also doesn't include any hints that the
-            # file was generated by geda, so we have to guess by context whether this is just geda being geda or
-            # potential user error.
-            excellon_settings = FileSettings(number_format=(2, 4))
-
-        elif generator == 'allegro':
-            # Allegro puts information that is absolutely vital for parsing its excellon files... into another file,
-            # next to the actual excellon file. Despite pretty much everyone else having figured out a way to put that
-            # info into the excellon file itself, even if only as a comment.
-            if 'excellon params' in filemap:
-                excellon_settings = parse_allegro_ncparam(filemap['excellon params'][0].read_text())
-                for file in filemap['excellon params']:
-                    if (external_tools := parse_allegro_logfile(file.read_text())):
-                        break
-                del filemap['excellon params']
-            # Ignore if we can't find the param file -- maybe the user has convinced Allegro to actually put this
-            # information into a comment, or maybe they have made Allegro just use decimal points like XNC does.
-
-            filemap = autoguess([ f for files in filemap.values() for f in files ])
-            if len(filemap) < 6:
-                raise SystemError('Cannot figure out gerber file mapping')
-            # FIXME use layer metadata from comments and ipc file if available
-
-        elif generator == 'zuken':
-            filemap = autoguess([ f for files in filemap.values() for f in files ])
-            if len(filemap) < 6:
-                raise SystemError('Cannot figure out gerber file mapping')
-            # FIXME use layer metadata from comments and ipc file if available
-
-        elif generator == 'altium':
-            if 'mechanical outline' in filemap:
-                # Use lowest-numbered mechanical layer as outline, ignore others.
-                mechs = {}
-                for layer in filemap['mechanical outline']:
-                    if layer.name.lower().endswith('gko'):
-                        filemap['mechanical outline'] = [layer]
-                        break
-
-                    if (m := re.match(r'.*\.gm([0-9]+)', layer.name, re.IGNORECASE)):
-                        mechs[int(m[1])] = layer
-                    else:
-                        break
-                else:
-                    filemap['mechanical outline'] = [sorted(mechs.items(), key=lambda x: x[0])[0][1]]
-
-        else:
-            excellon_settings = None
-
-        ambiguous = [ f'{key} ({", ".join(x.name for x in value)})' for key, value in filemap.items() if len(value) > 1 and not 'drill' in key ]
-        if ambiguous:
-            raise SystemError(f'Ambiguous layer names: {", ".join(ambiguous)}')
-
-        drill_layers = []
-        netlist = None
-        layers = {} # { tuple(key.split()): None for key in STANDARD_LAYERS }
-        for key, paths in filemap.items():
-            if len(paths) > 1 and not 'drill' in key:
-                raise ValueError(f'Multiple matching files found for {key} layer: {", ".join(value)}')
-
-            for path in paths:
-                id_result = identify_file(path.read_text())
-
-                if 'netlist' in key:
-                    layer = Netlist.open(path)
-
-                elif ('outline' in key or 'drill' in key) and id_result != 'gerber':
-                    if id_result is None:
-                        # Since e.g. altium uses ".txt" as the extension for its drill files, we have to assume the
-                        # current file might not be a drill file after all.
-                        continue
-
-                    if 'nonplated' in key:
-                        plated = False
-                    elif 'plated' in key:
-                        plated = True
-                    else:
-                        plated = None
-                    layer = ExcellonFile.open(path, plated=plated, settings=excellon_settings, external_tools=external_tools)
-                else:
-
-                    layer = GerberFile.open(path)
-
-                if key == 'mechanical outline':
-                    layers['mechanical', 'outline'] = layer
-
-                elif 'drill' in key:
-                    drill_layers.append(layer)
-
-                elif 'netlist' in key:
-                    if netlist:
-                        warnings.warn(f'Found multiple netlist files, using only first one. Have: {netlist.original_path.name}, got {path.name}')
-                    else:
-                        netlist = layer
-
-                else:
-                    side, _, use = key.partition(' ')
-                    layers[(side, use)] = layer
-
-                hints = set(layer.generator_hints) | { generator }
-                if len(hints) > 1:
-                    warnings.warn('File identification returned ambiguous results. Please raise an issue on the gerbonara '
-                            'tracker and if possible please provide these input files for reference.')
-
-        board_name = common_prefix([l.original_path.name for l in layers.values() if l is not None])
-        board_name = re.sub(r'^\W+', '', board_name)
-        board_name = re.sub(r'\W+$', '', board_name)
-        return kls(layers, drill_layers, netlist, board_name=board_name)
-
-    def save_to_directory(self, path, naming_scheme={}, overwrite_existing=True):
-        outdir = Path(path)
-        outdir.mkdir(parents=True, exist_ok=overwrite_existing)
-
-        def check_not_exists(path):
-            if path.exists() and not overwrite_existing:
-                raise SystemError(f'Path exists but overwrite_existing is False: {path}')
-
-        def get_name(layer_type, layer):
-            nonlocal naming_scheme, overwrite_existing
-
-            if (m := re.match('inner_([0-9]*) copper', layer_type)):
-                layer_type = 'inner copper'
-                num = int(m[1])
-            else:
-                num = None
-
-            if layer_type in naming_scheme:
-                path = outdir / naming_scheme[layer_type].format(layer_num=num, board_name=self.board_name)
-            else:
-                path = outdir / layer.original_path.name
-
-            check_not_exists(path)
-            return path
-
-        for (side, use), layer in self.graphic_layers.items():
-            outpath = get_name(f'{side} {use}', layer)
-            layer.save(outpath)
-
-        if naming_scheme:
-            self.normalize_drill_layers()
-
-            def save_layer(layer, layer_name):
-                nonlocal self, outdir, drill_layers, check_not_exists
-                path = outdir / drill_layers[layer_name].format(board_name=self.board_name)
-                check_not_exists(path)
-                layer.save(path)
-
-            drill_layers = { key.partition()[2]: value for key, value in naming_scheme if 'drill' in key }
-            if set(drill_layers) == {'plated', 'nonplated', 'unknown'}:
-                save_layer(self.drill_pth, 'plated')
-                save_layer(self.drill_npth, 'nonplated')
-                save_layer(self.drill_unknown, 'unknown')
-
-            elif 'plated' in drill_layers and len(drill_layers) == 2:
-                save_layer(self.drill_pth, 'plated')
-                merged = copy.copy(self.drill_npth)
-                merged.merge(self.drill_unknown)
-                save_layer(merged, list(set(drill_layers) - {'plated'})[0])
-
-            elif 'unknown' in drill_layers:
-                merged = copy.copy(self.drill_pth)
-                merged.merge(self.drill_npth)
-                merged.merge(self.drill_unknown)
-                save_layer(merged, 'unknown')
-
-            else:
-                raise ValueError('Namin scheme does not specify unknown drill layer')
-
-        else:
-            for layer in self.drill_layers:
-                outpath = outdir / layer.original_path.name
-                check_not_exists(outpath)
-                layer.save(outpath)
-
-        if self.netlist:
-            layer.save(get_name('other netlist', self.netlist))
-
-    def __str__(self):
-        names = [ f'{side} {use}' for side, use in self.graphic_layers ]
-        return f'<LayerStack {self.board_name} [{", ".join(names)}] and {len(self.drill_layers)} drill layers>'
-
-    def __repr__(self):
-        return str(self)
-
-    def merge_drill_layers(self):
-        target = ExcellonFile(comments='Drill files merged by gerbonara')
-
-        for layer in self.drill_layers:
-            if isinstance(layer, GerberFile):
-                layer = layer.to_excellon()
-
-            target.merge(layer)
-
-        self.drill_layers = [target]
-
-    def normalize_drill_layers(self):
-        # TODO: maybe also separate into drill and route?
-        drill_pth, drill_npth, drill_aux = [], [], []
-
-        for layer in self.drill_layers:
-            if isinstance(layer, GerberFile):
-                layer = layer.to_excellon()
-
-            if layer.is_plated:
-                drill_pth.append(layer)
-            elif layer.is_nonplated:
-                drill_pth.append(layer)
-            else:
-                drill_aux.append(layer)
-        
-        pth_out, *rest = drill_pth or [ExcellonFile()]
-        for layer in rest:
-            pth_out.merge(layer)
-
-        npth_out, *rest = drill_npth or [ExcellonFile()]
-        for layer in rest:
-            npth_out.merge(layer)
-
-        unknown_out = ExcellonFile()
-        for layer in drill_aux:
-            for obj in layer.objects:
-                if obj.plated is None:
-                    unknown_out.append(obj)
-                elif obj.plated:
-                    pth_out.append(obj)
-                else:
-                    npth_out.append(obj)
-
-        self.drill_pth, self.drill_npth = pth_out, npth_out
-        self.drill_unknown = unknown_out if unknown_out else None
-        self._drill_layers = []
-
-    @property
-    def drill_layers(self):
-        if self._drill_layers:
-            return self._drill_layers
-        if self.drill_pth or self.drill_npth or self.drill_unknown:
-            return [self.drill_pth, self.drill_npth, self.drill_unknown]
-        return []
-
-    @drill_layers.setter
-    def drill_layers(self, value):
-        self._drill_layers = value
-        self.drill_pth = self.drill_npth = self.drill_unknown = None
-
-    def __len__(self):
-        return len(self.layers)
-
-    def get(self, index, default=None):
-        if self.contains(key):
-            return self[key]
-        else:
-            return default
-
-    def __contains__(self, index):
-        if isinstance(index, str):
-            side, _, use = index.partition(' ')
-            return (side, use) in self.layers
-
-        elif isinstance(index, tuple):
-            return index in self.graphic_layers
-
-        return index < len(self.copper_layers)
-
-    def __getitem__(self, index):
-        if isinstance(index, str):
-            side, _, use = index.partition(' ')
-            return self.graphic_layers[(side, use)]
-
-        elif isinstance(index, tuple):
-            return self.graphic_layers[index]
-
-        return self.copper_layers[index]
-
-    @property
-    def copper_layers(self):
-        copper_layers = [ (key, layer) for key, layer in self.layers.items() if key.endswith('copper') ]
-
-        def sort_layername(val):
-            key, _layer = val
-            if key.startswith('top'):
-                return -1
-            if key.startswith('bottom'):
-                return 1e99
-            assert key.startswith('inner_')
-            return int(key[len('inner_'):])
-
-        return [ layer for _key, layer in sorted(copper_layers, key=sort_layername) ]
-
-    @property
-    def top_side(self):
-        return { key: self[key] for key in ('top copper', 'top mask', 'top silk', 'top paste', 'mechanical outline') }
-
-    @property
-    def bottom_side(self):
-        return { key: self[key] for key in ('bottom copper', 'bottom mask', 'bottom silk', 'bottom paste', 'mechanical outline') }
-
-    @property
-    def outline(self):
-        return self['mechanical outline']
-    
-    def _merge_layer(self, target, source):
-        if source is None:
-            return
-        
-        if self[target] is None:
-            self[target] = source
-
-        else:
-            self[target].merge(source)
-
-    def merge(self, other):
-        all_keys = set(self.layers.keys()) | set(other.layers.keys())
-        exclude = { key.split() for key in STANDARD_LAYERS }
-        all_keys = { key for key in all_keys if key not in exclude }
-        if all_keys:
-            warnings.warn('Cannot merge unknown layer types: {" ".join(all_keys)}')
-
-        for side in 'top', 'bottom':
-            for use in 'copper', 'mask', 'silk', 'paste':
-                self._merge_layer((side, use), other[side, use])
-
-        our_inner, their_inner = self.copper_layers[1:-1], other.copper_layers[1:-1]
-
-        if bool(our_inner) != bool(their_inner):
-            warnings.warn('Merging board without inner layers into board with inner layers, inner layers will be empty on first board.')
-
-        elif our_inner and their_inner:
-            warnings.warn('Merging boards with different inner layer counts. Will fill inner layers starting at core.')
-
-        diff = len(our_inner) - len(their_inner)
-        their_inner = ([None] * max(0, diff//2)) + their_inner + ([None] * max(0, diff//2))
-        our_inner = ([None] * max(0, -diff//2)) + their_inner + ([None] * max(0, -diff//2))
-
-        new_inner = []
-        for ours, theirs in zip(our_inner, their_inner):
-            if ours is None:
-                new_inner.append(theirs)
-            elif theirs is None:
-                new_inner.append(ours)
-            else:
-                ours.merge(theirs)
-                new_inner.append(ours)
-
-        for i, layer in enumerate(new_inner, start=1):
-            self[f'inner_{i} copper'] = layer
-
-        self._merge_layer('mechanical outline', other['mechanical outline'])
-
-        self.normalize_drill_layers()
-        other.normalize_drill_layers()
-
-        self.drill_pth.merge(other.drill_pth)
-        self.drill_npth.merge(other.drill_npth)
-        self.drill_unknown.merge(other.drill_unknown)
-        self.netlist.merge(other.netlist)
-

gerbonara/tests/conftest.py

@@ -1,30 +0,0 @@
-
-from pathlib import Path
-
-import pytest
-
-from .image_support import ImageDifference
-
-def pytest_assertrepr_compare(op, left, right):
-    if isinstance(left, ImageDifference) or isinstance(right, ImageDifference):
-        diff = left if isinstance(left, ImageDifference) else right
-        return [
-            f'Image difference assertion failed.',
-            f'    Calculated difference: {diff}',
-            f'    Histogram: {diff.histogram}', ]
-
-# store report in node object so tmp_gbr can determine if the test failed.
-@pytest.hookimpl(tryfirst=True, hookwrapper=True)
-def pytest_runtest_makereport(item, call):
-    outcome = yield
-    rep = outcome.get_result()
-    setattr(item, f'rep_{rep.when}', rep)
-
-fail_dir = Path('gerbonara_test_failures')
-def pytest_sessionstart(session):
-    if not hasattr(session.config, 'workerinput'): # on worker
-        return
-
-    # on coordinator
-    for f in chain(fail_dir.glob('*.gbr'), fail_dir.glob('*.png')):
-        f.unlink()

gerbonara/tests/image_support.py

@@ -1,257 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-#
-# Copyright 2022 Jan Götte <code@jaseg.de>
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-# Based on https://github.com/tracespace/tracespace
-#
-
-import subprocess
-from pathlib import Path
-import tempfile
-import textwrap
-import os
-from functools import total_ordering
-import shutil
-import bs4
-from contextlib import contextmanager
-import hashlib
-
-import numpy as np
-from PIL import Image
-
-cachedir = Path(__file__).parent / 'image_cache'
-cachedir.mkdir(exist_ok=True)
-
-@total_ordering
-class ImageDifference:
-    def __init__(self, value, histogram):
-        self.value = value
-        self.histogram = histogram
-
-    def __float__(self):
-        return float(self.value)
-
-    def __eq__(self, other):
-        return float(self) == float(other)
-
-    def __lt__(self, other):
-        return float(self) < float(other)
-
-    def __str__(self):
-        return str(float(self))
-
-@total_ordering
-class Histogram:
-    def __init__(self, value, size):
-        self.value, self.size = value, size
-
-    def __eq__(self, other):
-        other = np.array(other)
-        other[other == None] = self.value[other == None]
-        return (self.value == other).all()
-
-    def __lt__(self, other):
-        other = np.array(other)
-        other[other == None] = self.value[other == None]
-        return (self.value <= other).all()
-
-    def __getitem__(self, index):
-        return self.value[index]
-
-    def __str__(self):
-        return f'{list(self.value)} size={self.size}'
-
-
-def run_cargo_cmd(cmd, args, **kwargs):
-    if cmd.upper() in os.environ:
-        return subprocess.run([os.environ[cmd.upper()], *args], **kwargs)
-
-    try:
-        return subprocess.run([cmd, *args], **kwargs)
-
-    except FileNotFoundError:
-        return subprocess.run([str(Path.home() / '.cargo' / 'bin' / cmd), *args], **kwargs)
-
-def svg_to_png(in_svg, out_png, dpi=100, bg=None):
-    params = f'{dpi}{bg}'.encode()
-    digest = hashlib.blake2b(Path(in_svg).read_bytes() + params).hexdigest()
-    cachefile = cachedir / f'{digest}.png'
-
-    if not cachefile.is_file():
-        bg = 'black' if bg is None else bg
-        run_cargo_cmd('resvg', ['--background', bg, '--dpi', str(dpi), in_svg, cachefile], check=True, stdout=subprocess.DEVNULL)
-
-    shutil.copy(cachefile, out_png)
-
-to_gerbv_svg_units = lambda val, unit='mm': val*72 if unit == 'inch' else val/25.4*72
-
-def gerbv_export(in_gbr, out_svg, export_format='svg', origin=(0, 0), size=(6, 6), fg='#ffffff', bg='#000000', override_unit_spec=None):
-    params = f'{origin}{size}{fg}{bg}'.encode()
-    digest = hashlib.blake2b(Path(in_gbr).read_bytes() + params).hexdigest()
-    cachefile = cachedir / f'{digest}.svg'
-
-    if not cachefile.is_file():
-        # NOTE: gerbv seems to always export 'clear' polarity apertures as white, irrespective of --foreground, --background
-        # and project file color settings.
-        # TODO: File issue upstream.
-        with tempfile.NamedTemporaryFile('w') as f:
-            if override_unit_spec:
-                units, zeros, digits = override_unit_spec
-                print(f'{Path(in_gbr).name}: overriding excellon unit spec to {units=} {zeros=} {digits=}')
-                units = 0 if units == 'inch' else 1
-                zeros = {None: 0, 'leading': 1, 'trailing': 2}[zeros]
-                unit_spec = textwrap.dedent(f'''(cons 'attribs (list
-                        (list 'autodetect 'Boolean 0)
-                        (list 'zero_suppression 'Enum {zeros})
-                        (list 'units 'Enum {units})
-                        (list 'digits 'Integer {digits})
-                    ))''')
-            else:
-                unit_spec = ''
-
-            r, g, b = int(fg[1:3], 16), int(fg[3:5], 16), int(fg[5:], 16)
-            color = f"(cons 'color #({r*257} {g*257} {b*257}))"
-            f.write(f'''(gerbv-file-version! "2.0A")(define-layer! 0 (cons 'filename "{in_gbr}"){unit_spec}{color})''')
-            f.flush()
-            if override_unit_spec:
-                shutil.copy(f.name, '/tmp/foo.gbv')
-
-            x, y = origin
-            w, h = size
-            cmd = ['gerbv', '-x', export_format,
-                '--border=0',
-                f'--origin={x:.6f}x{y:.6f}', f'--window_inch={w:.6f}x{h:.6f}',
-                f'--background={bg}',
-                f'--foreground={fg}',
-                '-o', str(cachefile), '-p', f.name]
-            subprocess.run(cmd, check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
-    shutil.copy(cachefile, out_svg)
-
-@contextmanager
-def svg_soup(filename):
-    with open(filename, 'r') as f:
-        soup = bs4.BeautifulSoup(f.read(), 'xml')
-
-    yield soup
-
-    with open(filename, 'w') as f:
-        f.write(str(soup))
-
-def cleanup_gerbv_svg(soup):
-    for group in soup.find_all('g'):
-        # gerbv uses Cairo's SVG canvas. Cairo's SVG canvas is kind of broken. It has no support for unit
-        # handling at all, which means the output files just end up being in pixels at 72 dpi. Further, it
-        # seems gerbv's aperture macro rendering interacts poorly with Cairo's SVG export. gerbv renders
-        # aperture macros into a new surface, which for some reason gets clipped by Cairo to the given
-        # canvas size. This is just wrong, so we just nuke the clip path from these SVG groups here.
-        #
-        # Apart from being graphically broken, this additionally causes very bad rendering performance.
-        del group['clip-path']
-
-def gerber_difference(reference, actual, diff_out=None, svg_transform=None, size=(10,10), ref_unit_spec=None):
-    with tempfile.NamedTemporaryFile(suffix='.svg') as act_svg,\
-        tempfile.NamedTemporaryFile(suffix='.svg') as ref_svg:
-
-        gerbv_export(reference, ref_svg.name, size=size, export_format='svg', override_unit_spec=ref_unit_spec)
-        gerbv_export(actual, act_svg.name, size=size, export_format='svg')
-
-        with svg_soup(ref_svg.name) as soup:
-            if svg_transform is not None:
-                soup.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform
-            cleanup_gerbv_svg(soup)
-
-        with svg_soup(act_svg.name) as soup:
-            cleanup_gerbv_svg(soup)
-
-        return svg_difference(ref_svg.name, act_svg.name, diff_out=diff_out)
-
-def gerber_difference_merge(ref1, ref2, actual, diff_out=None, composite_out=None, svg_transform1=None, svg_transform2=None, size=(10,10)):
-    with tempfile.NamedTemporaryFile(suffix='.svg') as act_svg,\
-        tempfile.NamedTemporaryFile(suffix='.svg') as ref1_svg,\
-        tempfile.NamedTemporaryFile(suffix='.svg') as ref2_svg:
-
-        gerbv_export(ref1, ref1_svg.name, size=size, export_format='svg')
-        gerbv_export(ref2, ref2_svg.name, size=size, export_format='svg')
-        gerbv_export(actual, act_svg.name, size=size, export_format='svg')
-
-        with svg_soup(ref1_svg.name) as soup1:
-            if svg_transform1 is not None:
-                soup1.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform1
-            cleanup_gerbv_svg(soup1)
-
-            with svg_soup(ref2_svg.name) as soup2:
-                if svg_transform2 is not None:
-                    soup2.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform2
-                cleanup_gerbv_svg(soup2)
-
-                defs1 = soup1.find('defs')
-                if not defs1:
-                    defs1 = soup1.new_tag('defs')
-                    soup1.find('svg').insert(0, defs1)
-
-                defs2 = soup2.find('defs')
-                if defs2:
-                    defs2 = defs2.extract()
-                    # explicitly convert .contents into list here and below because else bs4 stumbles over itself
-                    # iterating because we modify the tree in the loop body.
-                    for c in list(defs2.contents):
-                        if hasattr(c, 'attrs'):
-                            c['id'] = 'gn-merge-b-' + c.attrs.get('id', str(id(c)))
-                        defs1.append(c)
-
-                for use in soup2.find_all('use', recursive=True):
-                    if (href := use.get('xlink:href', '')).startswith('#'):
-                        use['xlink:href'] = f'#gn-merge-b-{href[1:]}'
-
-                svg1 = soup1.find('svg')
-                for c in list(soup2.find('svg').contents):
-                    if hasattr(c, 'attrs'):
-                        c['id'] = 'gn-merge-b-' + c.attrs.get('id', str(id(c)))
-                    svg1.append(c)
-
-        if composite_out:
-            shutil.copyfile(ref1_svg.name, composite_out)
-
-        with svg_soup(act_svg.name) as soup:
-            cleanup_gerbv_svg(soup)
-
-        return svg_difference(ref1_svg.name, act_svg.name, diff_out=diff_out)
-
-def svg_difference(reference, actual, diff_out=None, background=None):
-    with tempfile.NamedTemporaryFile(suffix='-ref.png') as ref_png,\
-        tempfile.NamedTemporaryFile(suffix='-act.png') as act_png:
-
-        svg_to_png(reference, ref_png.name, bg=background)
-        svg_to_png(actual, act_png.name, bg=background)
-
-        return image_difference(ref_png.name, act_png.name, diff_out=diff_out)
-
-def image_difference(reference, actual, diff_out=None):
-    ref = np.array(Image.open(reference)).astype(float)
-    out = np.array(Image.open(actual)).astype(float)
-
-    ref, out = ref.mean(axis=2), out.mean(axis=2) # convert to grayscale
-    # TODO blur images here before comparison to mitigate aliasing issue
-    delta = np.abs(out - ref).astype(float) / 255
-    if diff_out:
-        Image.fromarray((delta*255).astype(np.uint8), mode='L').save(diff_out)
-
-    hist, _bins = np.histogram(delta, bins=10, range=(0, 1))
-    return (ImageDifference(delta.mean(), hist),
-            ImageDifference(delta.max(), hist),
-            Histogram(hist, out.size))
-
-

gerbonara/tests/resources/zuken-emulated/Gerber/Symbol-B.fph

@@ -1,9 +0,0 @@
-%FSLAX46Y46*%
-%MOMM*%
-%ADD10C,0.150000*%
-%ADD11C,0.100000*%
-%ADD12C,0.600000*%
-%ADD13C,0.120000*%
-
-%LPD*%
-G54D10*X168523809Y-90902380D02*X168523809Y-89902380D01*X168285714Y-89902380D01*X168142857Y-89950000D01*X168047619Y-90045238D01*X168000000Y-90140476D01*X167952380Y-90330952D01*X167952380Y-90473809D01*X168000000Y-90664285D01*X168047619Y-90759523D01*X168142857Y-90854761D01*X168285714Y-90902380D01*X168523809Y-90902380D01*X167571428Y-90616666D02*X167095238Y-90616666D01*X167666666Y-90902380D02*X167333333Y-89902380D01*X167000000Y-90902380D01*X166809523Y-89902380D02*X166238095Y-89902380D01*X166523809Y-90902380D02*X166523809Y-89902380D01*X165904761Y-90378571D02*X165571428Y-90378571D01*X165428571Y-90902380D02*X165904761Y-90902380D01*X165904761Y-89902380D01*X165428571Y-89902380D01*X168509523Y-78304761D02*X168366666Y-78352380D01*X168128571Y-78352380D01*X168033333Y-78304761D01*X167985714Y-78257142D01*X167938095Y-78161904D01*X167938095Y-78066666D01*X167985714Y-77971428D01*X168033333Y-77923809D01*X168128571Y-77876190D01*X168319047Y-77828571D01*X168414285Y-77780952D01*X168461904Y-77733333D01*X168509523Y-77638095D01*X168509523Y-77542857D01*X168461904Y-77447619D01*X168414285Y-77400000D01*X168319047Y-77352380D01*X168080952Y-77352380D01*X167938095Y-77400000D01*X167509523Y-78352380D02*X167509523Y-77352380D01*X166938095Y-78352380D01*X166938095Y-77352380D01*G54D11*G36*X168500000Y-89450000D02*G01X128500000Y-89450000D01*X128500000Y-78950000D01*X168500000Y-78950000D01*X168500000Y-89450000D01*G37*X168500000Y-89450000D02*X128500000Y-89450000D01*X128500000Y-78950000D01*X168500000Y-78950000D01*X168500000Y-89450000D01*G54D12*X131250000Y-58357142D02*X130678571Y-58357142D01*X130392857Y-58500000D01*X130107142Y-58785714D01*X129964285Y-59357142D01*X129964285Y-60357142D01*X130107142Y-60928571D01*X130392857Y-61214285D01*X130678571Y-61357142D01*X131250000Y-61357142D01*X131535714Y-61214285D01*X131821428Y-60928571D01*X131964285Y-60357142D01*X131964285Y-59357142D01*X131821428Y-58785714D01*X131535714Y-58500000D01*X131250000Y-58357142D01*X128678571Y-58357142D02*X128678571Y-60785714D01*X128535714Y-61071428D01*X128392857Y-61214285D01*X128107142Y-61357142D01*X127535714Y-61357142D01*X127250000Y-61214285D01*X127107142Y-61071428D01*X126964285Y-60785714D01*X126964285Y-58357142D01*X125964285Y-58357142D02*X124250000Y-58357142D01*X125107142Y-61357142D02*X125107142Y-58357142D01*X150071428Y-61357142D02*X150071428Y-58357142D01*X148642857Y-61357142D02*X148642857Y-58357142D01*X146928571Y-61357142D01*X146928571Y-58357142D01*G54D13*X117000000Y-76450000D02*X117000000Y-77150000D01*X118200000Y-77150000D02*X118200000Y-76450000D01*G54D10*X120242857Y-77157142D02*X120290476Y-77204761D01*X120433333Y-77252380D01*X120528571Y-77252380D01*X120671428Y-77204761D01*X120766666Y-77109523D01*X120814285Y-77014285D01*X120861904Y-76823809D01*X120861904Y-76680952D01*X120814285Y-76490476D01*X120766666Y-76395238D01*X120671428Y-76300000D01*X120528571Y-76252380D01*X120433333Y-76252380D01*X120290476Y-76300000D01*X120242857Y-76347619D01*X119290476Y-77252380D02*X119861904Y-77252380D01*X119576190Y-77252380D02*X119576190Y-76252380D01*X119671428Y-76395238D01*X119766666Y-76490476D01*X119861904Y-76538095D01*X118338095Y-77252380D02*X118909523Y-77252380D01*X118623809Y-77252380D02*X118623809Y-76252380D01*X118719047Y-76395238D01*X118814285Y-76490476D01*X118909523Y-76538095D01*X0Y0D02*M00*

podman/arch-testenv

@@ -0,0 +1,10 @@
+
+FROM docker.io/archlinux:latest
+MAINTAINER gerbolyze@jaseg.de
+RUN pacman --noconfirm -Syu
+RUN pacman --noconfirm -Sy git python python-pip base-devel python-numpy python-slugify python-lxml python-click python-pillow librsvg python-scipy python-sphinx python-pytest twine python-beautifulsoup4 gerbv rustup cargo rsync
+RUN python3 -m pip install pytest-parallel
+RUN rustup install stable
+RUN rustup default stable
+RUN cargo install usvg resvg
+

podman/debian-testenv

@@ -0,0 +1,11 @@
+
+FROM docker.io/debian:latest
+MAINTAINER gerbolyze@jaseg.de
+RUN env DEBIAN_FRONTEND=noninteractive apt update -y
+RUN env DEBIAN_FRONTEND=noninteractive apt install -y libopencv-dev libpugixml-dev libpangocairo-1.0-0 libpango1.0-dev libcairo2-dev clang make python3 git python3-wheel curl python3-pip python3-venv
+
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+RUN sh -c '. ~/.cargo/env && rustup install stable'
+RUN sh -c '. ~/.cargo/env && rustup default stable'
+RUN sh -c '. ~/.cargo/env && cargo install usvg'
+

podman/fedora-testenv

@@ -0,0 +1,7 @@
+
+FROM docker.io/fedora:latest
+MAINTAINER gerbolyze@jaseg.de
+RUN dnf update --refresh -y
+RUN dnf install -y python3 make clang opencv-devel pugixml-devel pango-devel cairo-devel rust cargo
+RUN cargo install usvg
+

podman/testdata/.gitignore

@@ -0,0 +1 @@
+git

podman/testdata/testscript.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -e 
+rsync -av /data/git git
+cd git
+
+python3 -m pytest $@

podman/ubuntu-testenv

@@ -0,0 +1,8 @@
+
+FROM docker.io/ubuntu:latest
+MAINTAINER gerbolyze@jaseg.de
+RUN env DEBIAN_FRONTEND=noninteractive apt update -y
+RUN env DEBIAN_FRONTEND=noninteractive apt install -y python3 git python3-wheel curl python3-pip python3-venv cargo gerbv
+RUN cargo install usvg resvg
+RUN python3 -m pip install numpy slugify lxml click pillow scipy sphinx pytest beautifulsoup4 pytest-parallel
+RUN env DEBIAN_FRONTEND=noninteractive apt install -y rsync

pyproject.toml

@@ -0,0 +1,72 @@
+[project]
+name = "gerbonara"
+version = "1.6.2"
+description = "Tools to handle Gerber and Excellon files in Python"
+readme = "README.md"
+license = "Apache-2.0"
+requires-python = ">=3.12"
+dependencies = ["click", "rtree", "quart"]
+
+authors = [
+  { name = "jaseg" },
+  { name = "XenGi" },
+]
+
+maintainers = [
+  { name = "Gerbonara maintainers", email = "gerbonara@jaseg.de" },
+]
+
+keywords = ["gerber", "excellon", "pcb", "RS274x", "EDA"]
+
+classifiers = [
+  "Development Status :: 5 - Production/Stable",
+  "Environment :: Console",
+  "Intended Audience :: Developers",
+  "Intended Audience :: Information Technology",
+  "Intended Audience :: Manufacturing",
+  "Intended Audience :: Science/Research",
+  "License :: OSI Approved :: Apache Software License",
+  "Topic :: Artistic Software",
+  "Topic :: Multimedia :: Graphics",
+  "Topic :: Printing",
+  "Topic :: Scientific/Engineering",
+  "Topic :: Scientific/Engineering :: Electronic Design Automation (EDA)",
+  "Topic :: Scientific/Engineering :: Image Processing",
+  "Topic :: Utilities",
+]
+
+[project.urls]
+Homepage = "https://jaseg.de/projects/gerbonara/"
+Documentation = "https://gerbolyze.gitlab.io/gerbonara/"
+Source = "https://git.jaseg.de/gerbonara.git"
+Tracker = "https://gitlab.com/gerbolyze/gerbonara/issues"
+
+[project.scripts]
+gerbonara = "gerbonara.cli:cli"
+protoserve = "gerbonara.cad.protoserve:main"
+
+[dependency-groups]
+dev = [
+    "pytest",
+    "pytest-xdist",
+    "numpy",
+    "scipy",
+    "tqdm",
+    "beautifulsoup4",
+    "lxml",
+    "pillow"
+    ]
+
+[build-system]
+requires = ["uv-build"]
+build-backend = "uv_build"
+
+[tool.pytest]
+testpaths = ["tests"]
+norecursedirs = ["*"]
+kicad_symbols_tag = "9.0.6"
+kicad_footprints_tag = "9.0.6"
+kicad_source_tag = "9.0.6"
+# Tag to use for container for footprint svg export
+# For a list of available tags, see https://hub.docker.com/r/kicad/kicad/tags
+kicad_container_tag = "9.0.6-full"

run-tests.sh

@@ -0,0 +1,33 @@
+#!/bin/sh
+
+set -e
+
+while [ $# -gt 0 ]; do
+    case $1 in
+        --parallel)
+            CONTAINER_ARGS="--workers auto $CONTAINER_ARGS"
+            shift;;
+        -x)
+            CONTAINER_ARGS="-x $CONTAINER_ARGS"
+            shift;;
+        --no-cache)
+            NO_CACHE=--no-cache
+            shift;;
+        *)
+            echo "Unknown argument \"$1\""
+            exit 1
+            shift;;
+    esac
+done
+
+mkdir -p podman/testdata/git
+git ls-tree --full-tree -r HEAD --name-only | rsync -lptgoDv --delete . --files-from - podman/testdata/git/
+#git clone --depth 1 . podman/testdata/git
+
+for distro in ubuntu-old ubuntu arch
+do
+    podman build $NO_CACHE -t gerbonara-$distro-testenv -f podman/$distro-testenv
+    mkdir -p /tmp/gerbonara-test-out
+    podman run --mount type=bind,src=podman/testdata,dst=/data,ro --mount type=bind,src=/tmp/gerbonara-test-out,dst=/out gerbonara-$distro-testenv /data/testscript.sh $CONTAINER_ARGS
+done
+

setup.py

@@ -1,62 +0,0 @@
-#!/usr/bin/env python3
-
-from pathlib import Path
-from setuptools import setup, find_packages
-import subprocess
-
-def version():
-    res = subprocess.run(['git', 'describe', '--tags', '--match', 'v*'], capture_output=True, check=True, text=True)
-    version, _, _rest = res.stdout.strip()[1:].partition('-')
-    return version
-
-setup(
-    name='gerbonara',
-    version=version(),
-    author='jaseg, XenGi',
-    author_email='gerbonara@jaseg.de',
-    description='Tools to handle Gerber and Excellon files in Python',
-    long_description=Path('README.md').read_text(),
-    long_description_content_type='text/markdown',
-    url='https://gitlab.com/gerbolyze/gerbonara',
-    project_urls={
-        # 'Documentation': 'https://packaging.python.org/tutorials/distributing-packages/',
-        # 'Funding': 'https://donate.pypi.org',
-        # 'Say Thanks!': 'http://saythanks.io/to/example',
-        'Source': 'https://gitlab.com/gerbonara/gerbonara',
-        'Tracker': 'https://gitlab.com/gerbonara/gerbonara/issues',
-    },
-    packages=find_packages(exclude=['tests']),
-    install_requires=['click'],
-    entry_points={
-        'console_scripts': [
-            'gerbonara = gerbonara.cli:cli',
-        ],
-    },
-    classifiers=[
-        'Development Status :: 4 - Beta',
-        #'Development Status :: 5 - Production/Stable',
-        'Environment :: Console',
-        'Intended Audience :: Developers',
-        'Intended Audience :: Information Technology',
-        'Intended Audience :: Manufacturing',
-        'Intended Audience :: Science/Research',
-        'License :: OSI Approved :: Apache Software License',
-        'Natural Language :: English',
-        'Operating System :: POSIX :: Linux',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3 :: Only',
-        'Programming Language :: Python :: 3.8',
-        'Programming Language :: Python :: 3.9',
-        'Programming Language :: Python :: 3.10',
-        'Topic :: Artistic Software',
-        'Topic :: Multimedia :: Graphics',
-        'Topic :: Printing',
-        'Topic :: Scientific/Engineering',
-        'Topic :: Scientific/Engineering :: Electronic Design Automation (EDA)',
-        'Topic :: Scientific/Engineering :: Image Processing',
-        'Topic :: Utilities',
-        'Typing :: Typed',
-    ],
-    keywords='gerber excellon pcb',
-    python_requires='>=3.8',
-)

src/gerbonara/NOTES

@@ -13,6 +13,7 @@ To do
 [X] Handle upverter output correctly: Upverter puts drils in a file called "design_export.xln" that actually contains
     Gerber, not Excellon
 [X] Add standard comment/attribute support for Gerber and Excellon
+[ ] Add attribute support to gerber output
 [X] Add file/lineno info to all warnings and syntax errors
 [X] Make sure we handle arcs with co-inciding start/end points correctly (G74: no arc, G75: full circle)
 [ ] Add allegro drill test files with different zero suppression settings
@@ -40,3 +41,4 @@ To do
 [ ] Add "number of parameters" property to ApertureMacro
 [ ] Aperture macro outline: Warn if first and last point are not the same.
 [ ] Make sure incremental mode actually works for gerber import
+[ ] Add text rendering function

src/gerbonara/__init__.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <code@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -20,12 +20,16 @@
 Gerbonara
 =========
 
-gerbonara provides utilities for working with Gerber (RS-274X) and Excellon files in python.
+gerbonara provides utilities for working with PCB artwork files in Gerber/RS274-X, XNC/Excellon and IPC-356 formats. It
+includes convenience functions to match file names to layer types that match the default settings of a number of common
+EDA tools.
 """
 
 from .rs274x import GerberFile
 from .excellon import ExcellonFile
 from .ipc356 import Netlist
 from .layers import LayerStack
+from .utils import MM, Inch
+from importlib.metadata import version
 
-__version__ = '0.9.0'
+__version__ = version('gerbonara')

src/gerbonara/__main__.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+import click
+from zipfile import is_zipfile
+from pathlib import Path
+
+from .layers import LayerStack
+from .rs274x import GerberFile
+
+
+@click.group()
+def cli():
+    pass
+
+@cli.command(help='Render a folder or zip of Gerber and Excellon files to a pretty, semi-photorealistic SVG.')
+@click.option('-t' ,'--top', help='Render board top side.', is_flag=True)
+@click.option('-b' ,'--bottom', help='Render board bottom side.', is_flag=True)
+@click.argument('input_zip_or_dir', type=click.Path(exists=True, path_type=Path))
+@click.argument('output_svg', required=False, default='-', type=click.File('w'))
+def pretty(input_zip_or_dir, output_svg, top, bottom):
+    if (bool(top) + bool(bottom))  != 1:
+        raise click.UsageError('Excactly one of --top or --bottom must be given when rendering a dir or zip of gerbers.')
+
+    stack = LayerStack.open(input_zip_or_dir, lazy=True)
+    print(f'Loaded {stack}')
+
+    svg = stack.to_pretty_svg(side=('top' if top else 'bottom'))
+
+    output_svg.write(str(svg))
+
+@cli.command(help='Render an individual Gerber or Excellon file to SVG')
+@click.option('-f', '--foreground', default='black', help='Foreground color')
+@click.option('-b', '--background', default='white', help='Background color used for "clear" areas.')
+@click.argument('input_gerber', type=click.Path(exists=True, dir_okay=False, path_type=Path))
+@click.argument('output_svg', required=False, default='-', type=click.File('w'))
+def render(input_gerber, output_svg, foreground, background):
+    layer = GerberFile.open(input_gerber)
+    output_svg.write(str(layer.to_svg(fg=foreground, bg=background)))
+
+if __name__ == '__main__':
+    cli()
+

src/gerbonara/aperture_macros/__init__.py

@@ -0,0 +1,18 @@
+
+from .parse import ApertureMacro, GenericMacros
+from .expression import (Expression,
+                        UnitExpression,
+                        ConstantExpression,
+                        VariableExpression,
+                        ParameterExpression,
+                        NegatedExpression,
+                        OperatorExpression)
+from .primitive import (Comment,
+                        Circle,
+                        VectorLine,
+                        CenterLine,
+                        Outline,
+                        Polygon,
+                        Moire,
+                        Thermal)
+

src/gerbonara/aperture_macros/expression.py

@@ -0,0 +1,379 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2021 Jan Sebastian Götte <gerbonara@jaseg.de>
+
+from dataclasses import dataclass
+import operator
+import re
+import ast
+import math
+
+from ..utils import LengthUnit, MM, Inch, MILLIMETERS_PER_INCH
+
+
+def expr(obj):
+    return obj if isinstance(obj, Expression) else ConstantExpression(obj)
+_make_expr = expr
+
+
+@dataclass(frozen=True, slots=True)
+class Expression:
+    def optimized(self, variable_binding={}):
+        return self
+
+    def __str__(self):
+        return f'<{self.to_gerber()}>'
+
+    def __repr__(self):
+        return f'<E {self.to_gerber()}>'
+
+    def converted(self, unit):
+        return self
+
+    def calculate(self, variable_binding={}, unit=None):
+        expr = self.converted(unit).optimized(variable_binding)
+        if not isinstance(expr, ConstantExpression):
+            raise IndexError(f'Cannot fully resolve expression due to unresolved parameters: residual expression {expr} under parameters {variable_binding}')
+        return expr.value
+
+    def __add__(self, other):
+        return OperatorExpression(operator.add, self, expr(other)).optimized()
+
+    def __radd__(self, other):
+        return expr(other) + self
+
+    def __sub__(self, other):
+        return OperatorExpression(operator.sub, self, expr(other)).optimized()
+
+    def __rsub__(self, other):
+        return expr(other) - self
+
+    def __mul__(self, other):
+        return OperatorExpression(operator.mul, self, expr(other)).optimized()
+
+    def __rmul__(self, other):
+        return expr(other) * self
+
+    def __truediv__(self, other):
+        return OperatorExpression(operator.truediv, self, expr(other)).optimized()
+
+    def __rtruediv__(self, other):
+        return expr(other) / self
+
+    def __neg__(self):
+        return NegatedExpression(self).optimized()
+
+    def __pos__(self):
+        return self
+
+    def parameters(self):
+        return tuple()
+
+    @property
+    def _operator(self):
+        return None
+
+
+@dataclass(frozen=True, slots=True)
+class UnitExpression(Expression):
+    expr: Expression
+    unit: LengthUnit
+
+    def __init__(self, expr, unit):
+        expr = _make_expr(expr)
+        if isinstance(expr, UnitExpression):
+            expr = expr.converted(unit)
+        object.__setattr__(self, 'expr', expr)
+        object.__setattr__(self, 'unit', unit)
+
+    def to_gerber(self, register_variable=None, unit=None):
+        return self.converted(unit).optimized().to_gerber(register_variable)
+
+    def __eq__(self, other):
+        return type(other) == type(self) and \
+            self.unit == other.unit and\
+            self.expr == other.expr
+
+    def __str__(self):
+        return f'<{self.expr.to_gerber()} {self.unit}>'
+
+    def __repr__(self):
+        return f'<UE {self.expr.to_gerber()} {self.unit}>'
+
+    def converted(self, unit):
+        if self.unit is None or unit is None or self.unit == unit:
+            return self.expr
+
+        elif MM == unit:
+            return self.expr * MILLIMETERS_PER_INCH
+
+        elif Inch == unit:
+            return self.expr / MILLIMETERS_PER_INCH
+
+        else:
+            raise ValueError(f'invalid unit {unit}, must be "inch" or "mm".')
+
+    def __add__(self, other):
+        if not isinstance(other, UnitExpression):
+            raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
+
+        if self.unit == other.unit or self.unit is None or other.unit is None:
+            return UnitExpression(self.expr + other.expr, self.unit)
+
+        if other.unit == 'mm': # -> and self.unit == 'inch'
+            return UnitExpression(self.expr + (other.expr / MILLIMETERS_PER_INCH), self.unit)
+        else: # other.unit == 'inch' and self.unit == 'mm'
+            return UnitExpression(self.expr + (other.expr * MILLIMETERS_PER_INCH), self.unit)
+
+    def __radd__(self, other):
+        # left hand side cannot have been an UnitExpression or __radd__ would not have been called
+        raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
+
+    def __sub__(self, other):
+        return (self + (-other)).optimized()
+
+    def __rsub__(self, other):
+        # see __radd__ above
+        raise ValueError('Unit mismatch: Can only add/subtract UnitExpression from UnitExpression, not scalar.')
+
+    def __mul__(self, other):
+        return UnitExpression(self.expr * other, self.unit)
+
+    def __rmul__(self, other):
+        return UnitExpression(other * self.expr, self.unit)
+
+    def __truediv__(self, other):
+        return UnitExpression(self.expr / other, self.unit)
+
+    def __rtruediv__(self, other):
+        return UnitExpression(other / self.expr, self.unit)
+
+    def __neg__(self):
+        return UnitExpression(-self.expr, self.unit)
+
+    def __pos__(self):
+        return self
+
+    def parameters(self):
+        return self.expr.parameters()
+
+
+@dataclass(frozen=True, slots=True)
+class ConstantExpression(Expression):
+    value: float
+
+    def __float__(self):
+        return float(self.value)
+
+    def __eq__(self, other):
+        try:
+            return math.isclose(self.value, float(other), abs_tol=1e-9)
+        except TypeError:
+            return False
+
+    def to_gerber(self, register_variable=None, unit=None):
+        if self == 0: # Avoid producing "-0" for negative floating point zeros
+            return '0'
+        return f'{self.value:.6f}'.rstrip('0').rstrip('.')
+
+    
+@dataclass(frozen=True, slots=True)
+class VariableExpression(Expression):
+    ''' An expression that encapsulates some other complex expression and will replace all occurences of it with a newly
+    allocated variable at export time.
+    '''
+    expr: Expression
+
+    def optimized(self, variable_binding={}):
+        opt = self.expr.optimized(variable_binding)
+        if isinstance(opt, OperatorExpression):
+            return self
+        else:
+            return opt
+
+    def __eq__(self, other):
+        return type(self) == type(other) and self.expr == other.expr
+
+    def to_gerber(self, register_variable=None, unit=None):
+        if register_variable is None:
+            return self.expr.to_gerber(None, unit)
+        else:
+            num = register_variable(self.expr.converted(unit).optimized())
+            return f'${num}'
+
+@dataclass(frozen=True, slots=True)
+class ParameterExpression(Expression):
+    ''' An expression that refers to a macro variable or parameter '''
+    number: int
+
+    def optimized(self, variable_binding={}):
+        if self.number in variable_binding:
+            return expr(variable_binding[self.number]).optimized(variable_binding)
+        return self
+
+    def __eq__(self, other):
+        return type(self) == type(other) and \
+                self.number == other.number
+
+    def to_gerber(self, register_variable=None, unit=None):
+        return f'${self.number}'
+
+    def parameters(self):
+        yield self
+
+
+@dataclass(frozen=True, slots=True)
+class NegatedExpression(Expression):
+    value: Expression
+
+    def optimized(self, variable_binding={}):
+        match self.value.optimized(variable_binding):
+            # -(-x) == x
+            case NegatedExpression(inner_value):
+                return inner_value
+            # -(x) == -x
+            case ConstantExpression(inner_value):
+                return ConstantExpression(-inner_value)
+            # -(x-y) == y-x
+            case OperatorExpression(operator.sub, l, r):
+                return OperatorExpression(operator.sub, r, l)
+            # Round very small values and negative floating point zeros to a (positive) zero
+            case 0:
+                return expr(0)
+            # Default case
+            case x:
+                return NegatedExpression(x)
+
+    @property
+    def _operator(self):
+        return self.value._operator
+
+    def __eq__(self, other):
+        return type(self) == type(other) and \
+                self.value == other.value
+
+    def to_gerber(self, register_variable=None, unit=None):
+        val_str = self.value.to_gerber(register_variable, unit)
+        if isinstance(self.value, (VariableExpression, ParameterExpression)):
+            return f'-{val_str}'
+        else:
+            return f'-({val_str})'
+
+
+@dataclass(frozen=True, slots=True)
+class OperatorExpression(Expression):
+    op: str
+    l: Expression
+    r: Expression
+
+    def __init__(self, op, l, r):
+        object.__setattr__(self, 'op', op)
+        object.__setattr__(self, 'l', expr(l))
+        object.__setattr__(self, 'r', expr(r))
+
+    def __eq__(self, other):
+        return type(self) == type(other) and \
+                self.op == other.op and \
+                self.l == other.l and \
+                self.r == other.r
+
+    @property
+    def _operator(self):
+        return self.op
+
+    def optimized(self, variable_binding={}):
+        l = self.l.optimized(variable_binding)
+        r = self.r.optimized(variable_binding)
+        
+        match (l, self.op, r):
+            case (ConstantExpression(), op, ConstantExpression()):
+                return ConstantExpression(self.op(float(l), float(r)))
+
+            # Minimize operations with neutral elements and zeros
+            # 0 + x == x
+            case (0, operator.add, r):
+                return r
+            # x + 0 == x
+            case (l, operator.add, 0):
+                return l
+            # 0 * x == 0
+            case (0, operator.mul, r):
+                return expr(0)
+            # x * 0 == 0
+            case (l, operator.mul, 0):
+                return expr(0)
+            # x * 1 == x
+            case (l, operator.mul, 1):
+                return l
+            # 1 * x == x
+            case (1, operator.mul, r):
+                return r
+            # x * -1 == -x
+            case (l, operator.mul, -1):
+                rv = -l
+            # -1 * x == -x
+            case (-1, operator.mul, r):
+                rv = -r
+            # x - 0 == x
+            case (l, operator.sub, 0):
+                return l
+            # 0 - x == -x (unary minus)
+            case (0, operator.sub, r):
+                rv = -r
+            # x - x == 0
+            case (l, operator.sub, r) if l == r:
+                return expr(0)
+            # x - -y == x + y
+            case (l, operator.sub, NegatedExpression(r)):
+                rv = (l + r)
+            # x / 1 == x
+            case (l, operator.truediv, 1):
+                return l
+            # x / -1 == -x
+            case (l, operator.truediv, -1):
+                rv = -l
+            # x / x == 1
+            case (l, operator.truediv, r) if l == r:
+                return expr(1)
+            # -x [*/] -y == x [*/] y
+            case (NegatedExpression(l), (operator.truediv | operator.mul) as op, NegatedExpression(r)):
+                rv = op(l, r)
+            # -x [*/] y == -(x [*/] y)
+            case (NegatedExpression(l), (operator.truediv | operator.mul) as op, r):
+                rv = NegatedExpression(op(l, r))
+            # x [*/] -y == -(x [*/] y)
+            case (l, (operator.truediv | operator.mul) as op, NegatedExpression(r)):
+                rv = NegatedExpression(op(l, r))
+            # x + -y == x - y
+            case (l, operator.add, NegatedExpression(r)):
+                rv = l-r
+            # -x + y == y - x
+            case (NegatedExpression(l), operator.add, r):
+                rv = r-l
+
+            case _: # default
+                return OperatorExpression(self.op, l, r)
+
+        return expr(rv).optimized(variable_binding)
+
+    def to_gerber(self, register_variable=None, unit=None):
+        lval = self.l.to_gerber(register_variable, unit)
+        rval = self.r.to_gerber(register_variable, unit)
+
+        if isinstance(self.l, OperatorExpression):
+            lval = f'({lval})'
+        if isinstance(self.r, OperatorExpression):
+            rval = f'({rval})'
+
+        op = {operator.add: '+',
+              operator.sub: '-',
+              operator.mul: 'x',
+              operator.truediv: '/'} [self.op]
+
+        return f'{lval}{op}{rval}'
+
+    def parameters(self):
+        yield from self.l.parameters()
+        yield from self.r.parameters()
+

src/gerbonara/aperture_macros/parse.py

@@ -0,0 +1,463 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2021 Jan Sebastian Götte <gerbonara@jaseg.de>
+
+from dataclasses import dataclass, field, replace, fields
+import operator
+import re
+import ast
+import copy
+import warnings
+import math
+
+from . import primitive as ap
+from .expression import *
+from ..apertures import ApertureMacroInstance
+from ..utils import MM
+
+# we make our own here instead of using math.degrees to make sure this works with expressions, too.
+def rad_to_deg(x):
+    return (x / math.pi) * 180
+
+def _map_expression(node, variables={}, parameters=set()):
+    if isinstance(node, ast.Constant):
+        return ConstantExpression(node.value)
+
+    elif isinstance(node, ast.BinOp):
+        op_map = {ast.Add: operator.add, ast.Sub: operator.sub, ast.Mult: operator.mul, ast.Div: operator.truediv}
+        return OperatorExpression(op_map[type(node.op)],
+                                  _map_expression(node.left, variables, parameters),
+                                  _map_expression(node.right, variables, parameters))
+
+    elif isinstance(node, ast.UnaryOp):
+        if type(node.op) == ast.UAdd:
+            return _map_expression(node.operand, variables, parameters)
+        else:
+            return NegatedExpression(_map_expression(node.operand, variables, parameters))
+
+    elif isinstance(node, ast.Name):
+        num = int(node.id[3:]) # node.id has format var[0-9]+
+        if num in variables:
+            return VariableExpression(variables[num])
+        else:
+            parameters.add(num)
+            return ParameterExpression(num)
+
+    else:
+        raise SyntaxError('Invalid aperture macro expression')
+
+def _parse_expression(expr, variables, parameters):
+    expr = expr.lower().replace('x', '*')
+    expr = re.sub(r'\$([0-9]+)', r'var\1', expr)
+    try:
+        parsed = ast.parse(expr, mode='eval').body
+    except SyntaxError as e:
+        raise SyntaxError('Invalid aperture macro expression') from e
+    return _map_expression(parsed, variables, parameters)
+
+@dataclass(frozen=True, slots=True)
+class ApertureMacro:
+    """ Definition of an aperture macro in a Gerber file.
+
+        An aperture macro is a collection of shape primitives that are flashed all at once. The properties of these
+        primitives such as their relative position and size can be given explicitly, or can be given as a basic
+        arithmetic expression (so +/-/*/:, no higher functions) based on parameters. After the macro is defined in the
+        Gerber file, it is *bound* to a particular set of parameter values in an aperture definition. One macro can be
+        used by zero, or by multiple aperture definitions. To flash a macro, you must first bind it in an aperture
+        definition, which can then be flash'ed.
+
+        Gerbonara calls these apertures that bind a macro :py:class:`~..apertures.ApertureMacroInst`. You can bind a
+        macro to a set of parameters by calling it:
+
+        .. code-block: python
+
+            # am is some instance of ApertureMacro
+            aperture_def = am(1, 2, 3)
+            gerber.objects.append(Flash(x=12, y=34, aperture=aperture_def))
+        
+        Internally, the aperture macro API uses millimeters though most functions allow you to pass an unit parameter.
+
+        When you want to programmatically create aperture macros, we recommend using :py:meth:`~.ApertureMacro.map` on a
+        dataclass-like class definition. Have a look at this code from :py:class:`~.GenericMacros`:
+
+        .. code-block: python
+
+            @ApertureMacro.map('GNR')
+            class rect:
+                w: float # width
+                h: float # height
+                hole_dia: float = 0
+                rotation: float = 0
+
+                def draw(self):
+                    yield ap.CenterLine('mm', 1, self.w, self.h, 0, 0, self.rotation * -deg_per_rad)
+                    yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+            # rect now is an instance of ApertureMacro
+
+        After this, you can bind this macro to an aperture by calling it. When you use this dataclass-like syntax,
+        keyword arguments are supported, and default values work like with normal dataclasses:
+            
+        .. code-block: python
+
+            # returns an instance of ApertureMacroInstance containing the given parameters
+            my_rect = GenericMacros.rect(w=12, h=34)
+
+            gerber.objects.append(Flash(x=12, y=34, aperture=my_rect))
+        
+        .. important::
+            Use your own programmatically defined aperture macros sparingly. While support is getting better, many
+            tools, including the expensive, commercial tools that PCB manufacturers use, still have bugs when handling
+            aperture macros. When using advanced macros with many primitives or with complex, embedded arithmetic
+            expressions, make sure to carefully check the manufacturing files provided by your PCB fab.
+
+            gerbonara currently handles embedded arithmetic expressions by *always* calculating them out since we have
+            recently seen high-end commercial tooling failing at issues as basic as operator precedence. This increases
+            file sizes very very slightly, but it makes sure that you get correct results.
+
+            This means that you can use gerbonara to calculate out aperture macros and hard-bake their values into the
+            gerber source. This can be useful if you have a file that includes complex macros that some manufacturer's
+            tooling can't handle on its own.
+            """
+
+    name: str = field(default=None, hash=False, compare=False)
+    num_parameters: int = 0
+    primitives: tuple = ()
+    comments: tuple = field(default=(), hash=False, compare=False)
+    _param_dataclass: object = field(default=None, hash=False, compare=False)
+
+    def __post_init__(self):
+        if self.name is None or re.match(r'GNX[0-9A-F]{16}', self.name):
+            # We can't use field(default_factory=...) here because that factory doesn't get a reference to the instance.
+            self._reset_name()
+
+    def _reset_name(self):
+        object.__setattr__(self, 'name', f'GNX{hash(self)&0xffffffffffffffff:016X}')
+
+    @classmethod
+    def map(our_kls, macro_name=None):
+        def wrapper(kls):
+            nonlocal our_kls, macro_name
+            dc = dataclass(kls)
+            
+            # Construct a mock instance of the dataclass with every field bound to its correpsonding ParameterExpression,
+            # then draw() it to get a list of bound macro primitives.
+            primitives = tuple(dc(*[ParameterExpression(i+1) for i in range(len(fields(dc)))]).draw())
+            name = macro_name if macro_name else f'GNM{kls.__name__}'
+
+            # Python allows a lot more unicode in class names than the Gerber spec allows in aperture macro names
+            if not re.fullmatch('[._$a-zA-Z][._$a-zA-Z0-9]{0,126}', name):
+                raise ValueError(f'Name {name!r} is invalid as an aperture macro name')
+
+            return our_kls(
+                name = name,
+                num_parameters = len(fields(dc)),
+                primitives = primitives,
+                comments = [l.strip() for l in dc.__doc__.strip().splitlines()],
+                _param_dataclass = dc)
+        return wrapper
+
+    def __call__(self, *args, unit=MM, **kwargs):
+        if self._param_dataclass:
+            # Above, in map(), we construct the dataclass with the ParameterExpression(i) as params to draw the macro
+            # primitives. Here, we construct it with the user's supplied concrete numeric parameters instead, and then
+            # extract a list of these parameters. This should work great as long as the user doesn't get too fancy with
+            # dataclass metaprogramming hackery.
+            bound = self._param_dataclass(*args, **kwargs)
+            return ApertureMacroInstance(macro=self, parameters=tuple(getattr(bound, f.name) or 0 for f in fields(bound)), unit=unit)
+
+    @classmethod
+    def parse_macro(kls, macro_name, body, unit):
+        comments = []
+        variables = {}
+        parameters = set()
+        primitives = []
+
+        blocks = body.split('*')
+        for block in blocks:
+            if not (block := block.strip()): # empty block
+                continue
+
+            if block.startswith('0 '): # comment
+                comments.append(block[2:])
+                continue
+            
+            block = re.sub(r'\s', '', block)
+
+            if block[0] == '$': # variable definition
+                try:
+                    name, _, expr = block.partition('=')
+                    number = int(name[1:])
+                    if number in variables:
+                        warnings.warn(f'Re-definition of aperture macro variable ${number} inside aperture macro "{macro_name}". Previous definition of ${number} was ${variables[number]}.')
+                    variables[number] = _parse_expression(expr, variables, parameters)
+                except Exception as e:
+                    raise SyntaxError(f'Error parsing variable definition {block!r}') from e
+
+            else: # primitive
+                primitive, *args = block.split(',')
+                args = [ _parse_expression(arg, variables, parameters) for arg in args ]
+                try:
+                    primitives.append(ap.PRIMITIVE_CLASSES[int(primitive)].from_arglist(unit, args))
+                except KeyError as e:
+                    raise SyntaxError(f'Unknown aperture macro primitive code {int(primitive)}')
+
+        return kls(macro_name, max(parameters, default=0), tuple(primitives), tuple(comments))
+
+    def __str__(self):
+        return f'<Aperture macro {self.name}, primitives {self.primitives}>'
+
+    def __repr__(self):
+        return str(self)
+
+    def dilated(self, offset, unit=MM):
+        new_primitives = []
+        for primitive in self.primitives:
+            try:
+                if primitive.exposure.calculate():
+                    new_primitives += primitive.dilated(offset, unit)
+            except IndexError:
+                warnings.warn('Cannot dilate aperture macro primitive with exposure value computed from macro variable.')
+                pass
+        return replace(self, primitives=tuple(new_primitives))
+
+    def substitute_params(self, params, unit=None, macro_name=None):
+        params = dict(enumerate(params, start=1))
+        return replace(self,
+                       num_parameters=0,
+                       name=macro_name,
+                       primitives=tuple(p.substitute_params(params, unit) for p in self.primitives),
+                       comments=(f'Fully substituted instance of {self.name} macro',
+                                 f'Original parameters: {"X".join(map(str, params.values())) if params else "none"}'))
+
+    def to_gerber(self, settings):
+        """ Serialize this macro's content (without the name) into Gerber using the given file unit """
+        comments = [ f'0 {c.replace("*", "_").replace("%", "_")}' for c in self.comments ]
+
+        subexpression_variables = {}
+        def register_variable(expr):
+            expr_str = expr.to_gerber(register_variable, settings.unit)
+            if expr_str not in subexpression_variables:
+                subexpression_variables[expr_str] = self.num_parameters + 1 + len(subexpression_variables)
+            return subexpression_variables[expr_str]
+
+        primitive_defs = [prim.to_gerber(register_variable, settings) for prim in self.primitives]
+        variable_defs = [f'${num}={expr_str}' for expr_str, num in subexpression_variables.items()]
+        return '*\n'.join(comments + variable_defs + primitive_defs)
+
+    def to_graphic_primitives(self, offset, rotation, parameters : [float], unit=None, polarity_dark=True):
+        parameters = dict(enumerate(parameters, start=1))
+        for primitive in self.primitives:
+            yield from primitive.to_graphic_primitives(offset, rotation, parameters, unit, polarity_dark)
+
+    def rotated(self, angle):
+        # aperture macro primitives use degree counter-clockwise, our API uses radians clockwise
+        return replace(self, primitives=tuple(
+            replace(primitive, rotation=primitive.rotation - rad_to_deg(angle)) for primitive in self.primitives))
+
+    def scaled(self, scale):
+        return replace(self, primitives=tuple(
+            primitive.scaled(scale) for primitive in self.primitives))
+
+
+var = ParameterExpression
+deg_per_rad = 180 / math.pi
+
+class GenericMacros:
+    """NOTE:
+       All generic macros have rotation values specified in **clockwise radians** like the rest of the user-facing API.
+    """
+
+    @ApertureMacro.map('GNC')
+    class circle:
+        """ Filled circle macro with an optional round hole
+        
+        :param float diameter: Diameter of the circle
+        :param hole_dia: Diameter of the hole (optional)
+        """
+        diameter: float
+        hole_dia: float = 0
+
+        def draw(self):
+            yield ap.Circle('mm', 1, self.diameter, 0, 0)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GNR')
+    class rect:
+        """ Axis-aligned rectangle with an optional round center hole.
+
+        :param float w: Width
+        :param float h: Height
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        w: float # width
+        h: float # height
+        hole_dia: float = 0
+        rotation: float = 0
+
+        def draw(self):
+            yield ap.CenterLine('mm', 1, self.w, self.h, 0, 0, self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GRR')
+    class rounded_rect:
+        """ Rectangle with circular arc corners and an optional round center hole.
+
+        :param float w: Width
+        :param float h: Height
+        :param float r: Corner radius
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        w: float # width
+        h: float # height
+        r: float # Corner radius
+        hole_dia: float = 0
+        rotation: float = 0
+
+        def draw(self):
+            yield ap.CenterLine('mm', 1, self.w-2*self.r, self.h, 0, 0, self.rotation * -deg_per_rad)
+            yield ap.CenterLine('mm', 1, self.w, self.h-2*self.r, 0, 0, self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 1, self.r*2, +(self.w/2-self.r), +(self.h/2-self.r), self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 1, self.r*2, +(self.w/2-self.r), -(self.h/2-self.r), self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 1, self.r*2, -(self.w/2-self.r), +(self.h/2-self.r), self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 1, self.r*2, -(self.w/2-self.r), -(self.h/2-self.r), self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GTR')
+    class isosceles_trapezoid:
+        """ Isosceles trapezoid with a wider bottom edge and narrower top edge, with an optional round center hole.
+
+        :param float w: Width of the bottom (wider) edge
+        :param float h: Height
+        :param float d: Length difference between bottom and top edges; top width = w - d
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        w: float # width
+        h: float # height
+        d: float # length difference between narrow side (top) and wide side (bottom)
+        hole_dia: float = 0
+        rotation: float = 0
+        
+        def draw(self):
+            yield ap.Outline('mm', 1, 4,
+                          (self.w/-2,            self.h/-2,
+                          self.w/-2+self.d/2,   self.h/2,
+                          self.w/2-self.d/2,    self.h/2,
+                          self.w/2,             self.h/-2,
+                          self.w/-2,            self.h/-2,),
+                          self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GRTR')
+    class rounded_isosceles_trapezoid:
+        """ Isosceles trapezoid with rounded corners and an optional round center hole. Unlike the rounded rectangle, the shape is defined by first defining a non-rounded trapezoid, which is then offet to the outside by the given margin.
+
+        :param float w: Width of the bottom (wider) edge
+        :param float h: Height
+        :param float d: Length difference between bottom and top edges; top width = w - d
+        :param float margin: Corner rounding radius
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        w: float
+        h: float
+        d: float # length difference between narrow side (top) and wide side (bottom)
+        margin: float
+        hole_dia: float = 0
+        rotation: float = 0
+
+        def draw(self):
+            rot = self.rotation * -deg_per_rad
+            yield ap.Outline('mm', 1, 4,
+                              (self.w/-2,            self.h/-2,
+                               self.w/-2+self.d/2,   self.h/2,
+                               self.w/2-self.d/2,    self.h/2,
+                               self.w/2,             self.h/-2,
+                               self.w/-2,            self.h/-2,),
+                             rot)
+
+            yield ap.VectorLine('mm', 1, self.margin*2, 
+                               self.w/-2,            self.h/-2,
+                               self.w/-2+self.d/2,   self.h/2,
+                               rot)
+            yield ap.VectorLine('mm', 1, self.margin*2, 
+                               self.w/-2+self.d/2,   self.h/2,
+                               self.w/2-self.d/2,    self.h/2,
+                               rot)
+            yield ap.VectorLine('mm', 1, self.margin*2, 
+                                self.w/2-self.d/2,    self.h/2,
+                                self.w/2,             self.h/-2,
+                                rot)
+            yield ap.VectorLine('mm', 1, self.margin*2,
+                                self.w/2,             self.h/-2,
+                                self.w/-2,            self.h/-2,
+                                rot)
+
+            yield ap.Circle('mm', 1, self.margin*2,
+                                self.w/-2,            self.h/-2,
+                            rot)
+            yield ap.Circle('mm', 1, self.margin*2, 
+                                self.w/-2+self.d/2,   self.h/2,
+                            rot)
+            yield ap.Circle('mm', 1, self.margin*2, 
+                                self.w/2-self.d/2,    self.h/2,
+                            rot)
+            yield ap.Circle('mm', 1, self.margin*2, 
+                                self.w/2,             self.h/-2,
+                            rot)
+
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GNO')
+    class obround:
+        """ Rectangle with semicircular end caps (stadium shape), with an optional round center hole. The long axis is along the X axis when rotation is zero.
+
+        :param float w: Total width including end caps; must satisfy w >= h
+        :param float h: Height, equal to the end cap diameter
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        w: float
+        h: float
+        hole_dia: float = 0
+        rotation: float = 0
+
+        def draw(self):
+            rot = self.rotation * -deg_per_rad
+            yield ap.CenterLine('mm', 1, self.w - self.h, self.h, 0, 0, rot)
+            yield ap.Circle('mm', 1, self.h, +(self.w-self.h)/2, 0, rot)
+            yield ap.Circle('mm', 1, self.h, -(self.w-self.h)/2, 0, rot)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+    @ApertureMacro.map('GNP')
+    class polygon:
+        """ Regular n-sided polygon with an optional round center hole.
+
+        :param int n: Number of sides
+        :param float diameter: Diameter of the circumscribed circle
+        :param float hole_dia: Diameter of the round hole (optional)
+        :param float rotation: Rotation in clockwise radians (optional)
+        """
+        n: int
+        diameter: float
+        hole_dia: float = 0
+        rotation: float = 0
+
+        def draw(self):
+            yield ap.Polygon('mm', 1, self.diameter, 0, 0, self.n, self.rotation * -deg_per_rad)
+            yield ap.Circle('mm', 0, self.hole_dia, 0, 0)
+
+
+if __name__ == '__main__':
+    import sys
+    #for line in sys.stdin:
+        #expr = _parse_expression(line.strip())
+        #print(expr, '->', expr.optimized())
+
+    for primitive in parse_macro(sys.stdin.read(), 'mm'):
+        print(primitive)
+

src/gerbonara/aperture_macros/primitive.py

@@ -0,0 +1,446 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
+
+import warnings
+import contextlib
+import math
+from dataclasses import dataclass, fields, replace
+
+from .expression import Expression, UnitExpression, ConstantExpression, expr
+
+from .. import graphic_primitives as gp
+from .. import graphic_objects as go
+from ..utils import rotate_point, LengthUnit, MM
+
+
+def point_distance(a, b):
+    x1, y1 = a
+    x2, y2 = b
+    return math.sqrt((x2 - x1)**2 + (y2 - y1)**2)
+
+
+# we make our own here instead of using math.degrees to make sure this works with expressions, too.
+def deg_to_rad(a):
+    return a * (math.pi / 180)
+
+
+def rad_to_deg(a):
+    return a * (180 / math.pi)
+
+
+@dataclass(frozen=True, slots=True)
+class Primitive:
+    unit: LengthUnit
+
+    def __post_init__(self):
+        for field in fields(self):
+            if field.type == UnitExpression:
+                value = getattr(self, field.name)
+                if not isinstance(value, UnitExpression):
+                    value = UnitExpression(expr(value), self.unit)
+                object.__setattr__(self, field.name, value)
+            elif field.type == Expression:
+                object.__setattr__(self, field.name, expr(getattr(self, field.name)))
+
+    def to_gerber(self, register_variable=None, settings=None):
+        return f'{self.code},' + ','.join(
+                getattr(self, field.name).optimized().to_gerber(register_variable, settings.unit)
+                for field in fields(self) if issubclass(field.type, Expression))
+    
+    def substitute_params(self, binding, unit):
+        out = replace(self, unit=unit, **{
+                       field.name: getattr(self, field.name).calculate(binding, unit)
+                       for field in fields(self) if issubclass(field.type, Expression)})
+        return out
+
+    def __str__(self):
+        attrs = ','.join(str(getattr(self, name)).strip('<>') for name in type(self).__annotations__)
+        return f'<{type(self).__name__} {attrs}>'
+
+    def __repr__(self):
+        return str(self)
+
+    @classmethod
+    def from_arglist(kls, unit, arglist):
+        return kls(unit, *arglist)
+
+    def parameters(self):
+        for field in fields(self):
+            if issubclass(field.type, Expression):
+                yield from getattr(self, field.name).parameters()
+
+    class Calculator:
+        def __init__(self, instance, variable_binding={}, unit=None):
+            self.instance = instance
+            self.variable_binding = variable_binding
+            self.unit = unit
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, _type, _value, _traceback):
+            pass
+
+        def __getattr__(self, name):
+            return getattr(self.instance, name).calculate(self.variable_binding, self.unit)
+
+        def __call__(self, expr):
+            return expr.calculate(self.variable_binding, self.unit)
+
+
+@dataclass(frozen=True, slots=True)
+class Circle(Primitive):
+    code = 1
+    exposure : Expression
+    diameter : UnitExpression
+    # center x/y
+    x : UnitExpression = 0
+    y : UnitExpression = 0
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            x, y = rotate_point(calc.x, calc.y, -(deg_to_rad(calc.rotation) + rotation), 0, 0)
+            x, y = x+offset[0], y+offset[1]
+
+            if math.isclose(calc.diameter, 0):
+                return []
+
+            return [ gp.Circle(x, y, calc.diameter/2, polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
+
+    def substitute_params(self, binding, unit):
+        with self.Calculator(self, binding, unit) as calc:
+            x, y = rotate_point(calc.x, calc.y, -deg_to_rad(calc.rotation), 0, 0)
+            new =  Circle(unit, self.exposure, calc.diameter, x, y)
+            return new
+
+    def dilated(self, offset, unit):
+        return replace(self, diameter=self.diameter + UnitExpression(offset, unit))
+
+    def scaled(self, scale):
+        return replace(self, x=self.x * UnitExpression(scale), y=self.y * UnitExpression(scale),
+                       diameter=self.diameter * UnitExpression(scale))
+
+
+@dataclass(frozen=True, slots=True)
+class VectorLine(Primitive):
+    code = 20
+    exposure : Expression
+    width : UnitExpression
+    start_x : UnitExpression
+    start_y : UnitExpression
+    end_x : UnitExpression
+    end_y : UnitExpression
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            center_x = (calc.end_x + calc.start_x) / 2
+            center_y = (calc.end_y + calc.start_y) / 2
+            delta_x = calc.end_x - calc.start_x
+            delta_y = calc.end_y - calc.start_y
+            length = point_distance((calc.start_x, calc.start_y), (calc.end_x, calc.end_y))
+
+            center_x, center_y = rotate_point(center_x, center_y, -(deg_to_rad(calc.rotation) + rotation), 0, 0)
+            center_x, center_y = center_x+offset[0], center_y+offset[1]
+            rotation += deg_to_rad(calc.rotation) + math.atan2(delta_y, delta_x)
+
+            if math.isclose(calc.width, 0):
+                return []
+
+            return [ gp.Rectangle(center_x, center_y, length, calc.width, rotation=rotation,
+                        polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
+
+    def substitute_params(self, binding, unit):
+        with self.Calculator(self, binding, unit) as calc:
+            x1, y1 = rotate_point(calc.start_x, calc.start_y, -deg_to_rad(calc.rotation), 0, 0)
+            x2, y2 = rotate_point(calc.end_x, calc.end_y, -deg_to_rad(calc.rotation), 0, 0)
+            return VectorLine(unit, calc.exposure, calc.width, x1, y1, x2, y2)
+
+    def dilated(self, offset, unit):
+        return replace(self, width=self.width + UnitExpression(2*offset, unit))
+
+    def scaled(self, scale):
+        return replace(self, 
+                       start_x=self.start_x * UnitExpression(scale),
+                       start_y=self.start_y * UnitExpression(scale),
+                       end_x=self.end_x * UnitExpression(scale),
+                       end_y=self.end_y * UnitExpression(scale))
+
+
+@dataclass(frozen=True, slots=True)
+class CenterLine(Primitive):
+    code = 21
+    exposure : Expression
+    width : UnitExpression
+    height : UnitExpression
+    # center x/y
+    x : UnitExpression = 0
+    y : UnitExpression = 0
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            rotation += deg_to_rad(calc.rotation)
+            x, y = gp.rotate_point(calc.x, calc.y, -rotation, 0, 0)
+            x, y = x+offset[0], y+offset[1]
+            w, h = calc.width, calc.height
+
+            if math.isclose(calc.width, 0) or math.isclose(calc.height, 0):
+                return []
+
+            return [ gp.Rectangle(x, y, w, h, rotation, polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
+
+    def substitute_params(self, binding, unit):
+        with self.Calculator(self, binding, unit) as calc:
+            x1, y1 = rotate_point(calc.x, calc.y-calc.height/2, -deg_to_rad(calc.rotation), 0, 0)
+            x2, y2 = rotate_point(calc.x, calc.y+calc.height/2, -deg_to_rad(calc.rotation), 0, 0)
+            return VectorLine(unit, calc.exposure, calc.width, x1, y1, x2, y2)
+
+    def dilated(self, offset, unit):
+        return replace(self, width=self.width + UnitExpression(2*offset, unit))
+
+    def scaled(self, scale):
+        return replace(self, 
+                       width=self.width * UnitExpression(scale),
+                       height=self.height * UnitExpression(scale),
+                       x=self.x * UnitExpression(scale),
+                       y=self.y * UnitExpression(scale))
+            
+
+@dataclass(frozen=True, slots=True)
+class Polygon(Primitive):
+    code = 5
+    exposure : Expression
+    n_vertices : Expression
+    # center x/y
+    x : UnitExpression
+    y : UnitExpression
+    diameter : UnitExpression
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            rotation += deg_to_rad(calc.rotation)
+            x, y = rotate_point(calc.x, calc.y, -rotation, 0, 0)
+            x, y = x+offset[0], y+offset[1]
+            print('xy', calc.x, calc.y)
+            return [ gp.ArcPoly.from_regular_polygon(x, y, calc.diameter/2, int(calc.n_vertices), rotation,
+                        polarity_dark=(bool(calc.exposure) == polarity_dark)) ]
+
+    def dilated(self, offset, unit):
+        return replace(self, diameter=self.diameter + UnitExpression(2*offset, unit))
+
+    def scale(self, scale):
+        return replace(self,
+                       diameter=self.diameter * UnitExpression(scale),
+                       x=self.x * UnitExpression(scale),
+                       y=self.y * UnitExpression(scale))
+            
+
+@dataclass(frozen=True, slots=True)
+class Moire(Primitive):
+    """ Deprecated, but still found in some really old gerber files. """
+    code = 6
+    # center x/y
+    x : UnitExpression
+    y : UnitExpression
+    d_outer : UnitExpression
+    line_thickness : UnitExpression
+    gap_w : UnitExpression
+    num_circles : Expression
+    crosshair_thickness : UnitExpression = 0
+    crosshair_length : UnitExpression =0
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            rotation += deg_to_rad(calc.rotation)
+            x, y = rotate_point(calc.x, calc.y, -rotation, 0, 0)
+            x, y = x+offset[0], y+offset[1]
+
+            if math.isclose(calc.d_outer, 0):
+                return []
+
+            pitch = calc.line_thickness + calc.gap_w
+            for i in range(int(round(calc.num_circles))):
+                yield gp.Circle(x, y, calc.d_outer/2 - i*pitch, polarity_dark=True)
+                yield gp.Circle(x, y, calc.d_inner/2 - i*pitch - calc.line_thickness, polarity_dark=False)
+
+            if math.isclose(calc.crosshair_thickness, 0, abs_tol=1e-6) or\
+                    math.isclose(calc.crosshair_length, 0, abs_tol=1e-6):
+                return
+
+            yield gp.Rectangle(x, y, crosshair_length, crosshair_thickness, rotation=rotation, polarity_dark=True)
+            yield gp.Rectangle(x, y, crosshair_thickness, crosshair_length, rotation=rotation, polarity_dark=True)
+
+    def dilate(self, offset, unit):
+        # I'd rather print a warning and produce graphically slightly incorrect output in these few cases here than
+        # producing macros that may evaluate to primitives with negative values.
+        warnings.warn('Attempted dilation of macro aperture thermal primitive. This is not supported.')
+
+    def scale(self, scale):
+        return replace(self, 
+                       d_outer=self.d_outer * UnitExpression(scale),
+                       d_inner=self.d_inner * UnitExpression(scale),
+                       gap_w=self.gap_w * UnitExpression(scale),
+                       x=self.x * UnitExpression(scale),
+                       y=self.y * UnitExpression(scale))
+
+
+@dataclass(frozen=True, slots=True)
+class Thermal(Primitive):
+    code = 7
+    # Note: Thermal primitives according to spec don't have an exposure variable
+    # center x/y
+    x : UnitExpression
+    y : UnitExpression
+    d_outer : UnitExpression
+    d_inner : UnitExpression
+    gap_w : UnitExpression
+    rotation : Expression = 0
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            rotation += deg_to_rad(calc.rotation)
+            x, y = rotate_point(calc.x, calc.y, -rotation, 0, 0)
+            x, y = x+offset[0], y+offset[1]
+
+            dark = True
+
+            if math.isclose(calc.d_outer, 0):
+                return []
+
+            return [
+                    gp.Circle(x, y, calc.d_outer/2, polarity_dark=dark),
+                    gp.Circle(x, y, calc.d_inner/2, polarity_dark=not dark),
+                    gp.Rectangle(x, y, calc.d_outer, calc.gap_w, rotation=rotation, polarity_dark=not dark),
+                    gp.Rectangle(x, y, calc.gap_w, calc.d_outer, rotation=rotation, polarity_dark=not dark),
+                    ]
+
+    def dilate(self, offset, unit):
+        # I'd rather print a warning and produce graphically slightly incorrect output in these few cases here than
+        # producing macros that may evaluate to primitives with negative values.
+        warnings.warn('Attempted dilation of macro aperture thermal primitive. This is not supported.')
+
+    def scale(self, scale):
+        return replace(self, 
+                       d_outer=self.d_outer * UnitExpression(scale),
+                       d_inner=self.d_inner * UnitExpression(scale),
+                       gap_w=self.gap_w * UnitExpression(scale),
+                       x=self.x * UnitExpression(scale),
+                       y=self.y * UnitExpression(scale))
+
+
+@dataclass(frozen=True, slots=True)
+class Outline(Primitive):
+    code = 4
+    exposure : Expression
+    length: Expression
+    coords: tuple
+    rotation: Expression = 0
+
+    def __post_init__(self):
+        if self.length is None:
+            object.__setattr__(self, 'length', expr(len(self.coords)//2-1))
+        else:
+            object.__setattr__(self, 'length', expr(self.length))
+        object.__setattr__(self, 'rotation', expr(self.rotation))
+        object.__setattr__(self, 'exposure', expr(self.exposure))
+
+        if self.length.calculate() != len(self.coords)//2-1:
+            raise ValueError('length must exactly equal number of segments, which is the number of points minus one')
+
+        if self.coords[-2:] != self.coords[:2]:
+            raise ValueError('Last point must equal first point')
+
+        object.__setattr__(self, 'coords', tuple(
+            UnitExpression(coord, self.unit) for coord in self.coords))
+
+    @property
+    def points(self):
+        for x, y in zip(self.coords[0::2], self.coords[1::2]):
+            yield x, y
+
+    @classmethod
+    def from_arglist(kls, unit, arglist):
+        if len(arglist[2:]) % 2 == 0:
+            return kls(unit=unit, exposure=arglist[0], length=arglist[1], coords=arglist[2:], rotation=0)
+        else:
+            return kls(unit=unit, exposure=arglist[0], length=arglist[1], coords=arglist[2:-1], rotation=arglist[-1])
+
+    def __str__(self):
+        return f'<Outline {len(self.coords)} points>'
+
+    def to_gerber(self, register_variable=None, settings=None):
+        rotation = self.rotation.optimized()
+        coords = ','.join(coord.optimized().to_gerber(register_variable, settings.unit) for coord in self.coords)
+        return f'{self.code},{self.exposure.optimized().to_gerber(register_variable)},{len(self.coords)//2-1},{coords},{rotation.to_gerber(register_variable)}'
+
+    def substitute_params(self, binding, unit):
+        with self.Calculator(self, binding, unit) as calc:
+            rotation = calc.rotation
+            coords = [ rotate_point(x.calculate(binding, unit), y.calculate(binding, unit), -deg_to_rad(rotation), 0, 0)
+                      for x, y in self.points ]
+            coords = [ e for point in coords for e in point ]
+            return Outline(unit, calc.exposure, calc.length, coords)
+
+    def parameters(self):
+        yield from Primitive.parameters(self)
+
+        for expr in self.coords:
+            yield from expr.parameters()
+
+    def to_graphic_primitives(self, offset, rotation, variable_binding={}, unit=None, polarity_dark=True):
+        with self.Calculator(self, variable_binding, unit) as calc:
+            rotation += deg_to_rad(calc.rotation)
+            bound_coords = [ rotate_point(calc(x), calc(y), -rotation, 0, 0) for x, y in self.points ]
+            bound_coords = [ (x+offset[0], y+offset[1]) for x, y in bound_coords ]
+            bound_radii = [None] * len(bound_coords)
+
+            if len(bound_coords) < 3:
+                return []
+
+            return [gp.ArcPoly(bound_coords, bound_radii, polarity_dark=(bool(calc.exposure) == polarity_dark))]
+
+    def dilated(self, offset, unit):
+        # we would need a whole polygon offset/clipping library here
+        warnings.warn('Attempted dilation of macro aperture outline primitive. This is not supported.')
+
+    def scaled(self, scale):
+        return replace(self, coords=tuple(x*scale for x in self.coords))
+
+
+@dataclass(frozen=True, slots=True)
+class Comment:
+    code = 0
+    comment: str
+
+    def to_gerber(self, register_variable=None, settings=None):
+        return f'0 {self.comment}'
+
+    def dilated(self, offset, unit):
+        return self
+
+    def scaled(self, scale):
+        return self
+
+
+PRIMITIVE_CLASSES = {
+    **{cls.code: cls for cls in [
+        Comment,
+        Circle,
+        VectorLine,
+        CenterLine,
+        Outline,
+        Polygon,
+        Moire,
+        Thermal,
+    ]},
+    # alternative codes
+    2: VectorLine,
+}
+

src/gerbonara/apertures.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,21 +16,18 @@
 # limitations under the License.
 #
 
+import warnings
 import math
 from dataclasses import dataclass, replace, field, fields, InitVar, KW_ONLY
+from functools import lru_cache
 
-from .aperture_macros.parse import GenericMacros
-from .utils import MM, Inch
+from .utils import LengthUnit, MM, Inch, sum_bounds
 
 from . import graphic_primitives as gp
 
 
 def _flash_hole(self, x, y, unit=None, polarity_dark=True):
-    if getattr(self, 'hole_rect_h', None) is not None:
-        w, h = self.unit.convert_to(unit, self.hole_dia), self.unit.convert_to(unit, self.hole_rect_h)
-        return [*self._primitives(x, y, unit, polarity_dark),
-                gp.Rectangle(x, y, w, h, rotation=self.rotation, polarity_dark=(not polarity_dark))]
-    elif self.hole_dia is not None:
+    if self.hole_dia is not None:
         return [*self._primitives(x, y, unit, polarity_dark),
                 gp.Circle(x, y, self.unit.convert_to(unit, self.hole_dia/2), polarity_dark=(not polarity_dark))]
     else:
@@ -40,7 +37,7 @@ def _strip_right(*args):
     args = list(args)
     while args and args[-1] is None:
         args.pop()
-    return args
+    return tuple(args)
 
 def _none_close(a, b):
     if a is None and b is None:
@@ -57,29 +54,14 @@ class Length:
     def __init__(self, obj_type):
         self.type = obj_type
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class Aperture:
     """ Base class for all apertures. """
     _ : KW_ONLY
-    #: :py:class:`gerbonara.utils.LengthUnit` used for all length fields of this aperture.
-    unit : str = None
-    #: GerberX2 attributes of this aperture. Note that this will only contain aperture attributes, not file attributes.
-    #: File attributes are stored in the :py:attr:`~.GerberFile.attrs` of the :py:class:`.GerberFile`.
-    attrs : dict = field(default_factory=dict)
-    #: Aperture index this aperture had when it was read from the Gerber file. This field is purely informational since
-    #: apertures are de-duplicated and re-numbered when writing a Gerber file. For `D10`, this field would be `10`. When
-    #: you programmatically create a new aperture, you do not have to set this.
-    original_number : int = None
-
-    @property
-    def hole_shape(self):
-        """ Get shape of hole based on :py:attr:`hole_dia` and :py:attr:`hole_rect_h`: "rect" or "circle" or None. """
-        if getattr(self, 'hole_rect_h') is not None:
-            return 'rect'
-        elif getattr(self, 'hole_dia') is not None:
-            return 'circle'
-        else:
-            return None
+    unit: LengthUnit = None
+    attrs: tuple = None
+    original_number: int = field(default=None, hash=False, compare=False)
+    _bounding_box: tuple = field(default=None, hash=False, compare=False)
 
     def _params(self, unit=None):
         out = []
@@ -108,6 +90,12 @@ class Aperture:
         """
         return self._primitives(x, y, unit, polarity_dark)
 
+    def bounding_box(self, unit=None):
+        if self._bounding_box is None:
+            object.__setattr__(self, '_bounding_box',
+                               sum_bounds((prim.bounding_box() for prim in self.flash(0, 0, MM, True))))
+        return MM.convert_bounds_to(unit, self._bounding_box)
+
     def equivalent_width(self, unit=None):
         """ Get the width of a line interpolated using this aperture in the given :py:class:`~.LengthUnit`.
 
@@ -120,16 +108,12 @@ class Aperture:
 
         :rtype: str
         """
-        # Hack: The standard aperture shapes C, R, O do not have a rotation parameter. To make this API easier to use,
-        # we emulate this parameter. Our circle, rectangle and oblong classes below have a rotation parameter. Only at
-        # export time during to_gerber, this parameter is evaluated. 
         unit = settings.unit if settings else None
-        actual_inst = self._rotated()
-        params = 'X'.join(f'{float(par):.4}' for par in actual_inst._params(unit) if par is not None)
+        params = 'X'.join(f'{float(par):.4}' for par in self._params(unit) if par is not None)
         if params:
-            return f'{actual_inst._gerber_shape_code},{params}'
+            return f'{self._gerber_shape_code},{params}'
         else:
-            return actual_inst._gerber_shape_code
+            return self._gerber_shape_code
 
     def to_macro(self):
         """ Convert this :py:class:`.Aperture` into an :py:class:`.ApertureMacro` inside an
@@ -137,24 +121,10 @@ class Aperture:
         """
         raise NotImplementedError()
 
-    def __eq__(self, other):
-        """ Compare two apertures. Apertures are compared based on their Gerber representation. Two apertures are
-        considered equal if their Gerber aperture definitions are identical.
-        """
-        # We need to choose some unit here.
-        return hasattr(other, 'to_gerber') and self.to_gerber(MM) == other.to_gerber(MM)
-
-    def _rotate_hole_90(self):
-        if self.hole_rect_h is None:
-            return {'hole_dia': self.hole_dia, 'hole_rect_h': None}
-        else:
-            return {'hole_dia': self.hole_rect_h, 'hole_rect_h': self.hole_dia}
-
-@dataclass(unsafe_hash=True)
+@dataclass(frozen=True, slots=True)
 class ExcellonTool(Aperture):
     """ Special Aperture_ subclass for use in :py:class:`.ExcellonFile`. Similar to :py:class:`.CircleAperture`, but
-    does not have :py:attr:`.CircleAperture.hole_dia` or :py:attr:`.CircleAperture.hole_rect_h`, and has the additional
-    :py:attr:`plated` attribute.
+    does not have :py:attr:`.CircleAperture.hole_dia`, and has the additional :py:attr:`plated` attribute.
     """
     _gerber_shape_code = 'C'
     _human_readable_shape = 'drill'
@@ -170,18 +140,6 @@ class ExcellonTool(Aperture):
     def to_xnc(self, settings):
         return 'C' + settings.write_excellon_value(self.diameter, self.unit)
 
-    def __eq__(self, other):
-        """ Compare two :py:class:`.ExcellonTool` instances. They are considered equal if their diameter and plating
-        match.
-        """
-        if not isinstance(other, ExcellonTool):
-            return False
-
-        if not self.plated == other.plated:
-            return False
-
-        return _none_close(self.diameter, self.unit(other.diameter, other.unit))
-
     def __str__(self):
         plated = '' if self.plated is None else (' plated' if self.plated else ' non-plated')
         return f'<Excellon Tool d={self.diameter:.3f}{plated} [{self.unit}]>'
@@ -192,19 +150,23 @@ class ExcellonTool(Aperture):
     # Internal use, for layer dilation.
     def dilated(self, offset, unit=MM):
         offset = unit(offset, self.unit)
+        if math.isclose(offset, 0, abs_tol=1e-6):
+            return self
         return replace(self, diameter=self.diameter+2*offset)
 
-    def _rotated(self):
+    @lru_cache()
+    def rotated(self, angle=0):
         return self
 
-    def to_macro(self):
-        return ApertureMacroInstance(GenericMacros.circle, self._params(unit=MM))
+    def to_macro(self, rotation=0):
+        from .aperture_macros.parse import GenericMacros
+        return ApertureMacroInstance(GenericMacros.circle, self._params(unit=MM), unit=MM)
 
     def _params(self, unit=None):
-        return [self.unit.convert_to(unit, self.diameter)]
+        return (self.unit.convert_to(unit, self.diameter),)
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class CircleAperture(Aperture):
     """ Besides flashing circles or rings, CircleApertures are used to set the width of a
     :py:class:`~.graphic_objects.Line` or :py:class:`~.graphic_objects.Arc`.
@@ -215,10 +177,6 @@ class CircleAperture(Aperture):
     diameter : Length(float)
     #: float with the hole diameter of this aperture in :py:attr:`unit` units. ``0`` for no hole.
     hole_dia : Length(float) = None
-    #: float or None. If not None, specifies a rectangular hole of size `hole_dia * hole_rect_h` instead of a round hole.
-    hole_rect_h : Length(float) = None
-    # float with radians. This is only used for rectangular holes (as circles are rotationally symmetric).
-    rotation : float = 0
 
     def _primitives(self, x, y, unit=None, polarity_dark=True):
         return [ gp.Circle(x, y, self.unit.convert_to(unit, self.diameter/2), polarity_dark=polarity_dark) ]
@@ -233,26 +191,34 @@ class CircleAperture(Aperture):
 
     def dilated(self, offset, unit=MM):
         offset = self.unit(offset, unit)
-        return replace(self, diameter=self.diameter+2*offset, hole_dia=None, hole_rect_h=None)
-
-    def _rotated(self):
-        if math.isclose(self.rotation % (2*math.pi), 0) or self.hole_rect_h is None:
+        if math.isclose(offset, 0, abs_tol=1e-6):
             return self
-        else:
-            return self.to_macro(self.rotation)
+        return replace(self, diameter=self.diameter+2*offset, hole_dia=None)
 
-    def to_macro(self):
-        return ApertureMacroInstance(GenericMacros.circle, self._params(unit=MM))
+    @lru_cache()
+    def rotated(self, angle=0):
+        return self
+
+    def scaled(self, scale):
+        return replace(self, 
+                       diameter=self.diameter*scale,
+                       hole_dia=None if self.hole_dia is None else self.hole_dia*scale)
+
+    def to_macro(self, rotation=0):
+        from .aperture_macros.parse import GenericMacros
+        return GenericMacros.circle(MM(self.diameter, self.unit),
+                                    MM(self.hole_dia, self.unit))
 
     def _params(self, unit=None):
         return _strip_right(
                 self.unit.convert_to(unit, self.diameter),
-                self.unit.convert_to(unit, self.hole_dia),
-                self.unit.convert_to(unit, self.hole_rect_h))
+                self.unit.convert_to(unit, self.hole_dia))
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class RectangleAperture(Aperture):
+    """ Gerber rectangle aperture. Can only be used for flashes, since the line width of an interpolation of a rectangle
+    aperture is not well-defined and there is no tool that implements it in a geometrically correct way. """
     _gerber_shape_code = 'R'
     _human_readable_shape = 'rect'
     #: float with the width of the rectangle in :py:attr:`unit` units.
@@ -261,14 +227,10 @@ class RectangleAperture(Aperture):
     h : Length(float)
     #: float with the hole diameter of this aperture in :py:attr:`unit` units. ``0`` for no hole.
     hole_dia : Length(float) = None
-    #: float or None. If not None, specifies a rectangular hole of size `hole_dia * hole_rect_h` instead of a round hole.
-    hole_rect_h : Length(float) = None
-    # Rotation in radians. This rotates both the aperture and the rectangular hole if it has one.
-    rotation : float = 0 # radians
 
     def _primitives(self, x, y, unit=None, polarity_dark=True):
         return [ gp.Rectangle(x, y, self.unit.convert_to(unit, self.w), self.unit.convert_to(unit, self.h),
-            rotation=self.rotation, polarity_dark=polarity_dark) ]
+            rotation=0, polarity_dark=polarity_dark) ]
 
     def __str__(self):
         return f'<rect aperture {self.w:.3}x{self.h:.3} [{self.unit}]>'
@@ -280,33 +242,40 @@ class RectangleAperture(Aperture):
 
     def dilated(self, offset, unit=MM):
         offset = self.unit(offset, unit)
-        return replace(self, w=self.w+2*offset, h=self.h+2*offset, hole_dia=None, hole_rect_h=None)
-
-    def _rotated(self):
-        if math.isclose(self.rotation % math.pi, 0):
+        if math.isclose(offset, 0, abs_tol=1e-6):
             return self
-        elif math.isclose(self.rotation % math.pi, math.pi/2):
-            return replace(self, w=self.h, h=self.w, **self._rotate_hole_90(), rotation=0)
-        else: # odd angle
-            return self.to_macro()
+        return replace(self, w=self.w+2*offset, h=self.h+2*offset, hole_dia=None)
 
-    def to_macro(self):
-        return ApertureMacroInstance(GenericMacros.rect,
-                [MM(self.w, self.unit),
-                    MM(self.h, self.unit),
-                    MM(self.hole_dia, self.unit) or 0,
-                    MM(self.hole_rect_h, self.unit) or 0,
-                    self.rotation])
+    @lru_cache()
+    def rotated(self, angle=0):
+        if math.isclose(angle % math.pi, 0, abs_tol=1e-6):
+            return self
+        elif math.isclose(angle % math.pi, math.pi/2, abs_tol=1e-6):
+            return replace(self, w=self.h, h=self.w, hole_dia=self.hole_dia)
+        else: # odd angle
+            return self.to_macro(angle)
+
+    def scaled(self, scale):
+        return replace(self, 
+                       w=self.w*scale,
+                       h=self.h*scale,
+                       hole_dia=None if self.hole_dia is None else self.hole_dia*scale)
+
+    def to_macro(self, rotation=0):
+        from .aperture_macros.parse import GenericMacros
+        return GenericMacros.rect(MM(self.w, self.unit),
+                                  MM(self.h, self.unit),
+                                  MM(self.hole_dia, self.unit),
+                                  rotation)
 
     def _params(self, unit=None):
         return _strip_right(
                 self.unit.convert_to(unit, self.w),
                 self.unit.convert_to(unit, self.h),
-                self.unit.convert_to(unit, self.hole_dia),
-                self.unit.convert_to(unit, self.hole_rect_h))
+                self.unit.convert_to(unit, self.hole_dia))
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class ObroundAperture(Aperture):
     """ Aperture whose shape is the convex hull of two circles of equal radii.
 
@@ -322,14 +291,10 @@ class ObroundAperture(Aperture):
     h : Length(float)
     #: float with the hole diameter of this aperture in :py:attr:`unit` units. ``0`` for no hole.
     hole_dia : Length(float) = None
-    #: float or None. If not None, specifies a rectangular hole of size `hole_dia * hole_rect_h` instead of a round hole.
-    hole_rect_h : Length(float) = None
-    #: Rotation in radians. This rotates both the aperture and the rectangular hole if it has one.
-    rotation : float = 0
 
     def _primitives(self, x, y, unit=None, polarity_dark=True):
         return [ gp.Line.from_obround(x, y, self.unit.convert_to(unit, self.w), self.unit.convert_to(unit, self.h),
-            rotation=self.rotation, polarity_dark=polarity_dark) ]
+            polarity_dark=polarity_dark) ]
 
     def __str__(self):
         return f'<obround aperture {self.w:.3}x{self.h:.3} [{self.unit}]>'
@@ -338,35 +303,47 @@ class ObroundAperture(Aperture):
 
     def dilated(self, offset, unit=MM):
         offset = self.unit(offset, unit)
-        return replace(self, w=self.w+2*offset, h=self.h+2*offset, hole_dia=None, hole_rect_h=None)
-
-    def _rotated(self):
-        if math.isclose(self.rotation % math.pi, 0):
+        if math.isclose(offset, 0, abs_tol=1e-6):
             return self
-        elif math.isclose(self.rotation % math.pi, math.pi/2):
-            return replace(self, w=self.h, h=self.w, **self._rotate_hole_90(), rotation=0)
-        else:
-            return self.to_macro()
+        return replace(self, w=self.w+2*offset, h=self.h+2*offset, hole_dia=None)
 
-    def to_macro(self):
+    @lru_cache()
+    def rotated(self, angle=0):
+        if math.isclose(angle % math.pi, 0, abs_tol=1e-6):
+            return self
+        elif math.isclose(angle % math.pi, math.pi/2, abs_tol=1e-6):
+            return replace(self, w=self.h, h=self.w, hole_dia=self.hole_dia)
+        else:
+            return self.to_macro(angle)
+
+    def scaled(self, scale):
+        return replace(self, 
+                       w=self.w*scale,
+                       h=self.h*scale,
+                       hole_dia=None if self.hole_dia is None else self.hole_dia*scale)
+
+    def to_macro(self, rotation=0):
         # generic macro only supports w > h so flip x/y if h > w
-        inst = self if self.w > self.h else replace(self, w=self.h, h=self.w, **_rotate_hole_90(self), rotation=self.rotation-90)
-        return ApertureMacroInstance(GenericMacros.obround,
-                [MM(inst.w, self.unit),
-                 MM(ints.h, self.unit),
-                 MM(inst.hole_dia, self.unit),
-                 MM(inst.hole_rect_h, self.unit),
-                 inst.rotation])
+        if self.w > self.h:
+            inst = self
+        else:
+            rotation -= -math.pi/2
+            inst = replace(self, w=self.h, h=self.w, hole_dia=self.hole_dia)
+
+        from .aperture_macros.parse import GenericMacros
+        return GenericMacros.obround(MM(inst.w, self.unit),
+                                     MM(inst.h, self.unit),
+                                     MM(inst.hole_dia, self.unit) or 0,
+                                     rotation)
 
     def _params(self, unit=None):
         return _strip_right(
                 self.unit.convert_to(unit, self.w),
                 self.unit.convert_to(unit, self.h),
-                self.unit.convert_to(unit, self.hole_dia),
-                self.unit.convert_to(unit, self.hole_rect_h))
+                self.unit.convert_to(unit, self.hole_dia))
 
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class PolygonAperture(Aperture):
     """ Aperture whose shape is a regular n-sided polygon (e.g. pentagon, hexagon etc.). Note that this only supports
     round holes.
@@ -383,7 +360,7 @@ class PolygonAperture(Aperture):
     hole_dia : Length(float) = None
 
     def __post_init__(self):
-        self.n_vertices = int(self.n_vertices)
+        object.__setattr__(self, 'n_vertices', int(self.n_vertices))
 
     def _primitives(self, x, y, unit=None, polarity_dark=True):
         return [ gp.ArcPoly.from_regular_polygon(x, y, self.unit.convert_to(unit, self.diameter)/2, self.n_vertices,
@@ -394,26 +371,46 @@ class PolygonAperture(Aperture):
 
     def dilated(self, offset, unit=MM):
         offset = self.unit(offset, unit)
+        if math.isclose(offset, 0, abs_tol=1e-6):
+            return self
         return replace(self, diameter=self.diameter+2*offset, hole_dia=None)
 
     flash = _flash_hole
 
-    def _rotated(self):
-        return self
+    @lru_cache()
+    def rotated(self, angle=0):
+        if angle != 0:
+            return replace(self, rotation=self.rotation + angle)
+        else:
+            return self
+
+    def scaled(self, scale):
+        return replace(self, 
+                       diameter=self.diameter*scale,
+                       hole_dia=None if self.hole_dia is None else self.hole_dia*scale)
 
     def to_macro(self):
-        return ApertureMacroInstance(GenericMacros.polygon, self._params(MM))
+        from .aperture_macros.parse import GenericMacros
+        return GenericMacros.polygon(self.n_vertices,
+                                     MM(self.diameter, self.unit),
+                                     MM(self.hole_dia, self.unit),
+                                     self.rotation)
 
     def _params(self, unit=None):
-        rotation = self.rotation % (2*math.pi / self.n_vertices) if self.rotation is not None else None
+        rotation = self.rotation % (2*math.pi / self.n_vertices)
+        if math.isclose(rotation, 0, abs_tol=1e-6):
+            rotation = None
+        else:
+            rotation = math.degrees(rotation)
+
         if self.hole_dia is not None:
             return self.unit.convert_to(unit, self.diameter), self.n_vertices, rotation, self.unit.convert_to(unit, self.hole_dia)
-        elif rotation is not None and not math.isclose(rotation, 0):
+        elif rotation is not None and not math.isclose(rotation, 0, abs_tol=1e-6):
             return self.unit.convert_to(unit, self.diameter), self.n_vertices, rotation
         else:
             return self.unit.convert_to(unit, self.diameter), self.n_vertices
 
-@dataclass
+@dataclass(frozen=True, slots=True)
 class ApertureMacroInstance(Aperture):
     """ One instance of an aperture macro. An aperture macro defined with an ``AM`` statement can be instantiated by
     multiple ``AD`` aperture definition statements using different parameters. An :py:class:`.ApertureMacroInstance` is
@@ -425,10 +422,7 @@ class ApertureMacroInstance(Aperture):
     macro : object
     #: The parameters to the :py:class:`.ApertureMacro`. All elements should be floats or ints. The first item in the
     #: list is parameter ``$1``, the second is ``$2`` etc.
-    parameters : list
-    #: Aperture rotation in radians. When saving, a copy of the :py:class:`.ApertureMacro` is re-written with this
-    #: rotation.
-    rotation : float = 0
+    parameters : tuple = ()
 
     @property
     def _gerber_shape_code(self):
@@ -436,30 +430,39 @@ class ApertureMacroInstance(Aperture):
 
     def _primitives(self, x, y, unit=None, polarity_dark=True):
         out = list(self.macro.to_graphic_primitives(
-                offset=(x, y), rotation=self.rotation,
+                offset=(x, y), rotation=0,
                 parameters=self.parameters, unit=unit, polarity_dark=polarity_dark))
         return out
 
     def dilated(self, offset, unit=MM):
+        if math.isclose(offset, 0, abs_tol=1e-6):
+            return self
         return replace(self, macro=self.macro.dilated(offset, unit))
 
-    def _rotated(self):
-        if math.isclose(self.rotation % (2*math.pi), 0):
+    @lru_cache()
+    def rotated(self, angle=0.0):
+        if math.isclose(angle % (2*math.pi), 0, abs_tol=1e-6):
             return self
         else:
-            return self.to_macro()
+            return self.to_macro(angle)
 
-    def to_macro(self):
-        return replace(self, macro=self.macro.rotated(self.rotation), rotation=0)
+    def to_macro(self, rotation=0.0):
+        return replace(self, macro=self.macro.rotated(rotation))
 
-    def __eq__(self, other):
-        return hasattr(other, 'macro') and self.macro == other.macro and \
-                hasattr(other, 'params') and self.params == other.params and \
-                hasattr(other, 'rotation') and self.rotation == other.rotation
+    def scaled(self, scale):
+        return replace(self, macro=self.macro.scaled(scale))
+
+    def calculate_out(self, unit=None, macro_name=None):
+        return replace(self,
+                       parameters=tuple(),
+                       macro=self.macro.substitute_params(self._params(unit), unit, macro_name))
 
     def _params(self, unit=None):
         # We ignore "unit" here as we convert the actual macro, not this instantiation.
         # We do this because here we do not have information about which parameter has which physical units.
-        return tuple(self.parameters)
-
+        parameters = self.parameters
+        if len(parameters) > self.macro.num_parameters:
+            warnings.warn(f'Aperture definition using macro {self.macro.name} has more parameters than the macro uses.')
+            parameters = parameters[:self.macro.num_parameters]
+        return tuple(parameters)
 

src/gerbonara/cad/breakout.py

@@ -0,0 +1,138 @@
+
+from dataclasses import dataclass
+
+from ..utils import MM
+from .primitives import *
+
+
+@dataclass
+class PadRing(Positioned):
+    w: int
+    h: int
+    pitch: float = 2.54
+    clearance: float = 0.2
+    rows: int = 2
+    trace_width: float = 0.4
+    drill_dia: float = 0.9
+    stagger: bool = False
+
+    def ports(self):
+        x, y, rotation = self.abs_pos
+
+        x += self.pitch/2
+        y += self.pitch/2
+
+        x += self.pitch * self.rows
+        y += self.pitch * self.rows
+
+        pad_dia = self.pitch - 2*self.clearance - self.trace_width
+        offset = pad_dia/2 - self.trace_width/2
+
+        for i in range(1, self.w):
+            yield (x+self.pitch/2 + i*self.pitch, y+offset)
+            yield (x+self.pitch/2 + i*self.pitch, y+(self.h+1)*self.pitch-offset)
+
+        for i in range(0, self.w):
+            yield (x + (i+1)*self.pitch, y+offset)
+            yield (x + (i+1)*self.pitch, y+(self.h+1)*self.pitch-offset)
+
+        for i in range(1, self.h):
+            yield (x+offset, y+self.pitch/2 + i*self.pitch)
+            yield (x+(self.w+1)*self.pitch-offset, y+self.pitch/2 + i*self.pitch)
+
+        for i in range(0, self.h):
+            yield (x+offset, y + (i+1)*self.pitch)
+            yield (x+(self.w+1)*self.pitch-offset, y + (i+1)*self.pitch)
+
+
+    def generate(self, bbox, border_text, unit=MM):
+        x, y, rotation = self.abs_pos
+
+        x += self.pitch/2
+        y += self.pitch/2
+
+        x += self.pitch * self.rows
+        y += self.pitch * self.rows
+
+        pad_dia = self.pitch - 2*self.clearance - self.trace_width
+
+        for i in range(self.w + 2 + 2*(self.rows-1)):
+            for j in range(self.rows):
+                yield THTPad.circle(x + (i - (self.rows - 1))*self.pitch, y - j*self.pitch, self.drill_dia, pad_dia, paste=False)
+                yield THTPad.circle(x + (i - (self.rows - 1))*self.pitch, y + (self.h + 1 + j)*self.pitch, self.drill_dia, pad_dia, paste=False)
+
+            if self.rows >= 2 and 1 <= i < self.w:
+                yield Trace(self.trace_width, start=(x+i*self.pitch, y-self.pitch), end=(x+(i + 0.5)*self.pitch, y+pad_dia/2 - self.trace_width/2))
+                yield Trace(self.trace_width, start=(x+i*self.pitch, y+(self.h+2)*self.pitch), end=(x+(i + 0.5)*self.pitch, y+(self.h+1)*self.pitch -pad_dia/2 + self.trace_width/2), orientation=('cw',))
+
+        for i in range(1, self.h+1):
+            for j in range(self.rows):
+                yield THTPad.circle(x - j*self.pitch, y + i*self.pitch, self.drill_dia, pad_dia, paste=False)
+                yield THTPad.circle(x + (self.w + 1 + j)*self.pitch, y + i*self.pitch, self.drill_dia, pad_dia, paste=False)
+
+        for i in range(1, self.h):
+            yield (x+offset, y+self.pitch/2 + i*self.pitch)
+            yield (x+(self.w+1)*self.pitch-offset, y+self.pitch/2 + i*self.pitch)
+
+
+    def generate(self, bbox, border_text, unit=MM):
+        x, y, rotation = self.abs_pos
+
+        x += self.pitch/2
+        y += self.pitch/2
+
+        x += self.pitch * self.rows
+        y += self.pitch * self.rows
+
+        pad_dia = self.pitch - 2*self.clearance - self.trace_width
+
+        for i in range(self.w + 2 + 2*(self.rows-1)):
+            for j in range(self.rows):
+                yield THTPad.circle(x + (i - (self.rows - 1))*self.pitch, y - j*self.pitch, self.drill_dia, pad_dia, paste=False)
+                yield THTPad.circle(x + (i - (self.rows - 1))*self.pitch, y + (self.h + 1 + j)*self.pitch, self.drill_dia, pad_dia, paste=False)
+
+            if self.rows >= 2 and 1 <= i < self.w:
+                yield Trace(self.trace_width, start=(x+i*self.pitch, y-self.pitch), end=(x+(i + 0.5)*self.pitch, y+pad_dia/2 - self.trace_width/2))
+                yield Trace(self.trace_width, start=(x+i*self.pitch, y+(self.h+2)*self.pitch), end=(x+(i + 0.5)*self.pitch, y+(self.h+1)*self.pitch -pad_dia/2 + self.trace_width/2), orientation=('cw',))
+
+        for i in range(1, self.h+1):
+            for j in range(self.rows):
+                yield THTPad.circle(x - j*self.pitch, y + i*self.pitch, self.drill_dia, pad_dia, paste=False)
+                yield THTPad.circle(x + (self.w + 1 + j)*self.pitch, y + i*self.pitch, self.drill_dia, pad_dia, paste=False)
+
+            if self.rows >= 2 and i < self.h:
+                yield Trace(self.trace_width,
+                            start=(
+                                x-self.pitch,
+                                y+i*self.pitch),
+                            end=(
+                                x+pad_dia/2 - self.trace_width/2,
+                                y+(i + 0.5)*self.pitch),
+                            orientation=('cw',))
+                yield Trace(self.trace_width,
+                            start=(
+                                x+(self.w+2)*self.pitch,
+                                y+i*self.pitch),
+                            end=(
+                                x+(self.w+1)*self.pitch -pad_dia/2 + self.trace_width/2,
+                                y+(i + 0.5)*self.pitch))
+
+
+def _breakout_demo():
+    b = Board(100, 80)
+    
+    ring = PadRing(5, 5, 8, 12)
+    for obj in ring.generate(None, None):
+        b.add(obj)
+
+    for x, y in ring.ports():
+        b.add(Trace(0.1, start=(23, 27), end=(x, y)))
+
+    with open('/tmp/test.svg', 'w') as f:
+        f.write(str(b.pretty_svg()))
+    b.layer_stack().save_to_directory('/tmp/testdir')
+
+
+if __name__ == '__main__':
+    _breakout_demo()
+

src/gerbonara/cad/data/center-pad-spikes.kicad_mod

@@ -0,0 +1,16 @@
+(module center-pad-spikes (layer F.Cu) (tedit 5B6B1C50)
+  (fp_text reference REF** (at 0 -1.4) (layer F.SilkS) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (fp_text value center-pad (at 0.1 -2.7) (layer F.Fab) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (pad 1 smd custom (at -0.06 -0.085) (size 0.47 0.52) (layers *.Cu *.Mask)
+    (options (clearance outline) (anchor rect))
+    (primitives
+      (gr_poly (pts
+         (xy -0.585 0.085) (xy 0.06 -0.56) (xy 0.357 -0.263) (xy 0.583 -0.263) (xy 0.235 0.085)
+         (xy 0.582 0.432) (xy 0.407 0.432) (xy 0.407 0.607) (xy 0.06 0.26) (xy -0.288 0.608)
+         (xy -0.288 0.382)) (width 0.001))
+    ))
+)

src/gerbonara/cad/data/pad-between-spiked.kicad_mod

@@ -0,0 +1,24 @@
+(module pad-between-spiked (layer F.Cu) (tedit 5B6B1D89)
+  (descr "Through hole pin header")
+  (tags "pin header")
+  (fp_text reference REF** (at 0 -5.1) (layer F.SilkS) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (fp_text value pad-between (at 0 -3.1) (layer F.Fab) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (pad 1 smd custom (at 0 -0.06) (size 0.7 0.85) (layers *.Cu *.Mask)
+    (options (clearance outline) (anchor rect))
+    (primitives
+      (gr_poly (pts
+         (xy -0.55 -0.44) (xy -0.325 -0.44) (xy 0 -0.765) (xy 0.325 -0.44) (xy 0.55 -0.44)
+         (xy 0.35 -0.24) (xy 0.35 0.36) (xy 0.55 0.56) (xy 0.338 0.56) (xy 0.338 0.763)
+         (xy 0 0.425) (xy -0.01 0.425) (xy -0.348 0.763) (xy -0.348 0.56) (xy -0.55 0.56)
+         (xy -0.35 0.36) (xy -0.35 -0.24)) (width 0.001))
+    ))
+  (model Pin_Headers.3dshapes/Pin_Header_Straight_1x01.wrl
+    (at (xyz 0 0 0))
+    (scale (xyz 1 1 1))
+    (rotate (xyz 0 0 90))
+  )
+)

src/gerbonara/cad/data/tht-0.8.kicad_mod

@@ -0,0 +1,16 @@
+(module tht-0.8 (layer F.Cu) (tedit 58D96FE6)
+  (descr "Through hole pin header")
+  (tags "pin header")
+  (fp_text reference REF** (at 0 -5.1) (layer F.SilkS) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (fp_text value tht-0.8 (at 0 -3.1) (layer F.Fab) hide
+    (effects (font (size 1 1) (thickness 0.15)))
+  )
+  (pad 1 thru_hole circle (at 0 0) (size 1.4 1.4) (drill 0.8) (layers *.Cu *.Mask))
+  (model Pin_Headers.3dshapes/Pin_Header_Straight_1x01.wrl
+    (at (xyz 0 0 0))
+    (scale (xyz 1 1 1))
+    (rotate (xyz 0 0 90))
+  )
+)

src/gerbonara/cad/kicad/__init__.py

@@ -0,0 +1 @@
+

src/gerbonara/cad/kicad/base_types.py

@@ -0,0 +1,630 @@
+import string
+import time
+from dataclasses import field, replace
+import math
+import uuid
+from contextlib import contextmanager
+from itertools import cycle
+
+from .sexp import *
+from .sexp_mapper import *
+from ...newstroke import Newstroke
+from ...utils import rotate_point, sum_bounds, Tag, MM
+from ...layers import LayerStack
+from ... import apertures as ap
+from ... import graphic_objects as go
+
+
+LAYER_MAP_K2G = {
+        'F.Cu': ('top', 'copper'),
+        'B.Cu': ('bottom', 'copper'),
+        'F.SilkS': ('top', 'silk'),
+        'B.SilkS': ('bottom', 'silk'),
+        'F.Paste': ('top', 'paste'),
+        'B.Paste': ('bottom', 'paste'),
+        'F.Mask': ('top', 'mask'),
+        'B.Mask': ('bottom', 'mask'),
+        'B.CrtYd': ('bottom', 'courtyard'),
+        'F.CrtYd': ('top', 'courtyard'),
+        'B.Fab': ('bottom', 'fabrication'),
+        'F.Fab': ('top', 'fabrication'),
+        'B.Adhes': ('bottom', 'adhesive'),
+        'F.Adhes': ('top', 'adhesive'),
+        'Dwgs.User': ('mechanical', 'drawings'),
+        'Cmts.User': ('mechanical', 'comments'),
+        'Edge.Cuts': ('mechanical', 'outline'),
+        }
+
+LAYER_MAP_G2K = {v: k for k, v in LAYER_MAP_K2G.items()}
+
+
+class BBoxMixin:
+    def bounding_box(self, unit=MM):
+        if not hasattr(self, '_bounding_box'):
+            (min_x, min_y), (max_x, max_y) = sum_bounds(fe.bounding_box(unit) for fe in self.render())
+            # Convert back from gerbonara's coordinates to kicad coordinates.
+            self._bounding_box = (min_x, -max_y), (max_x, -min_y)
+
+        return self._bounding_box
+
+
+@sexp_type('uuid')
+class UUID:
+    value: str = field(default_factory=uuid.uuid4)
+
+    def __deepcopy__(self, memo):
+        return UUID()
+
+    def __after_parse__(self, parent):
+        self.value = str(self.value)
+
+    def before_sexp(self):
+        self.value = str(self.value)
+
+    def bump(self):
+        self.value = uuid.uuid4()
+
+
+@sexp_type('group')
+class Group:
+    locked: Flag() = False
+    name: str = ""
+    id: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    members: Named(Array(str)) = field(default_factory=list)
+
+
+@sexp_type('color')
+class Color:
+    r: int = None
+    g: int = None
+    b: int = None
+    a: float = None
+    
+    def __bool__(self):
+        return self.r or self.b or self.g or not math.isclose(self.a, 0, abs_tol=1e-3)
+
+    def svg(self, default=None):
+        if default and not self:
+            return default
+
+        return f'rgba({self.r} {self.g} {self.b} {self.a})'
+
+
+@sexp_type('stroke')
+class Stroke:
+    width: Named(float) = 0.254
+    type: Named(AtomChoice(Atom.dash, Atom.dot, Atom.dash_dot_dot, Atom.dash_dot, Atom.default, Atom.solid)) = Atom.default
+    color: Color = None
+
+    def svg_color(self, default=None):
+        if self.color:
+            return self.color.svg(default)
+        else:
+            return default
+    
+    def svg_attrs(self, default_color=None):
+        w = self.width
+        if not (color := self.color or default_color):
+            return {}
+
+        attrs = {'stroke': color,
+                'stroke_linecap': 'round',
+                'stroke_linejoin': 'round',
+                'stroke_width': self.width or 0.254}
+
+        if self.type not in (Atom.default, Atom.solid):
+            attrs['stroke_dasharray'] = {
+                    Atom.dash: f'{w*5:.3f},{w*5:.3f}',
+                    Atom.dot: f'{w*2:.3f},{w*2:.3f}',
+                    Atom.dash_dot: f'{w*5:.3f},{w*3:.3f}{w:.3f},{w*3:.3f}',
+                    Atom.dash_dot_dot: f'{w*5:.3f},{w*3:.3f}{w:.3f},{w*3:.3f}{w:.3f},{w*3:.3f}',
+                    }[self.type]
+
+        return attrs
+
+
+@sexp_type('fill')
+class Fill:
+    type: Named(AtomChoice(Atom.none, Atom.outline, Atom.background, Atom.color)) = Atom.none
+    color: Color = None
+
+
+class WidthMixin:
+    def __post_init__(self):
+        if self.width is not None:
+            self.stroke = Stroke(self.width)
+
+
+class Dasher:
+    def __init__(self, obj):
+        if obj.stroke:
+            w = obj.stroke.width if obj.stroke.width not in (None, 0, 0.0) else 0.254
+            t = obj.stroke.type
+        else:
+            w = obj.width or 0
+            t = Atom.solid
+            
+        self.width = w
+        gap = 4*w
+        dot = 0
+        dash = 11*w
+        self.pattern = {
+                Atom.dash: [dash, gap],
+                Atom.dot: [dot, gap],
+                Atom.dash_dot_dot: [dash, gap, dot, gap, dot, gap],
+                Atom.dash_dot: [dash, gap, dot, gap],
+                Atom.default: [1e99],
+                Atom.solid: [1e99]}[t]
+        self.solid = t in (Atom.default, Atom.solid)
+        self.start_x, self.start_y = None, None
+        self.cur_x, self.cur_y = None, None
+        self.segments = []
+
+    def move(self, x, y):
+        if self.cur_x is None:
+            self.start_x, self.start_y = x, y
+        self.cur_x, self.cur_y = x, y
+
+    def line(self, x, y):
+        if x is None or y is None:
+            raise ValueError('line() called before move()')
+        self.segments.append((self.cur_x, self.cur_y, x, y))
+        self.cur_x, self.cur_y = x, y
+
+    def close(self):
+        self.segments.append((self.cur_x, self.cur_y, self.start_x, self.start_y))
+        self.cur_x, self.cur_y = None, None
+
+    @staticmethod
+    def _interpolate(x1, y1, x2, y2, length):
+        dx, dy = x2-x1, y2-y1
+        total = math.hypot(dx, dy)
+        if total == 0:
+            return x2, y2
+        frac = length / total
+        return x1 + dx*frac, y1 + dy*frac
+
+    def __iter__(self):
+        it = iter(self.segments)
+        segment_remaining, segment_pos = 0, 0
+
+        if self.width is None or self.width < 1e-3:
+            return
+
+        for length, stroked in cycle(zip(self.pattern, cycle([True, False]))):
+            length = max(1e-12, length)
+            while length > 0:
+                if segment_remaining == 0:
+                    try:
+                        x1, y1, x2, y2 = next(it)
+                    except StopIteration:
+                        return
+                    dx, dy = x2-x1, y2-y1
+                    lx, ly = x1, y1
+                    segment_remaining = math.hypot(dx, dy)
+                    segment_pos = 0
+
+                if segment_remaining > length:
+                    segment_pos += length
+                    ix, iy = self._interpolate(x1, y1, x2, y2, segment_pos)
+                    segment_remaining -= length
+                    if stroked:
+                        yield lx, ly, ix, iy
+                    lx, ly = ix, iy
+                    break
+
+                else:
+                    length -= segment_remaining
+                    segment_remaining = 0
+                    if stroked:
+                        yield lx, ly, x2, y2
+
+    def svg(self, **kwargs):
+        if 'fill' not in kwargs:
+            kwargs['fill'] = 'none'
+        if 'stroke' not in kwargs:
+            kwargs['stroke'] = 'black'
+        if 'stroke_width' not in kwargs:
+            kwargs['stroke_width'] = 0.254
+        if 'stroke_linecap' not in kwargs:
+            kwargs['stroke_linecap'] = 'round'
+
+        d = ' '.join(f'M {x1:.3f} {y1:.3f} L {x2:.3f} {y2:.3f}' for x1, y1, x2, y2 in self)
+        return Tag('path', d=d, **kwargs)
+
+
+@sexp_type('xy')
+class XYCoord:
+    x: float = 0
+    y: float = 0
+
+    def __init__(self, x=None, y=None):
+        if x is None:
+            self.x, self.y = None, None
+        elif isinstance(x, XYCoord):
+            self.x, self.y = x.x, x.y
+        elif isinstance(x, (tuple, list)):
+            self.x, self.y = x
+        elif hasattr(x, 'abs_pos'):
+            self.x, self.y, _1, _2 = x.abs_pos
+        elif hasattr(x, 'at'):
+            self.x, self.y = x.at.x, x.at.y
+        else:
+            self.x, self.y = x, y
+
+    def __iter__(self):
+        return iter((self.x, self.y))
+
+    def __getitem__(self, index):
+        return (self.x, self.y)[index]
+
+    def __setitem__(self, index, value):
+        if index == 0:
+            self.x = value
+        elif index == 1:
+            self.y = value
+        else:
+            raise IndexError(f'Invalid 2D point coordinate index {index}')
+
+    def within_distance(self, x, y, dist):
+        return math.dist((x, y), (self.x, self.y)) < dist
+
+    def isclose(self, other, tol=1e-3):
+        return math.isclose(self.x, other.x, tol) and math.isclose(self.y, other.y, tol)
+
+    def with_offset(self, x=0, y=0):
+        return replace(self, x=self.x+x, y=self.y+y)
+
+    def with_rotation(self, angle, cx=0, cy=0):
+        x, y = rotate_point(self.x, self.y, angle, cx, cy)
+        return replace(self, x=x, y=y)
+
+
+@sexp_type('pts')
+class PointList:
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        _tag, *values = obj
+        return [map_sexp(XYCoord, elem, parent=parent, path=path) for elem in values]
+
+    @classmethod
+    def __sexp__(kls, value):
+        yield [kls.name_atom, *(e for elem in value for e in elem.__sexp__(elem))]
+
+
+@sexp_type('arc')
+class Arc:
+    start: Rename(XYCoord) = None
+    mid: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+
+
+@sexp_type('pts')
+class ArcPointList:
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        _tag, *values = obj
+        return [map_sexp((XYCoord if elem[0] == 'xy' else Arc), elem, parent=parent, path=path) for elem in values]
+
+    @classmethod
+    def __sexp__(kls, value):
+        yield [kls.name_atom, *(e for elem in value for e in elem.__sexp__(elem))]
+
+
+@sexp_type('net')
+class Net:
+    index: int = 0
+    name: str = ''
+
+
+class NetMixin:
+    def reset_net(self):
+        self.net = Net()
+
+    @property
+    def net_index(self):
+        if self.net is None:
+            return 0
+        return self.net.index
+
+    @property
+    def net_name(self):
+        if self.net is None:
+            return ''
+        return self.net.name
+
+
+@sexp_type('xyz')
+class XYZCoord:
+    x: float = 0
+    y: float = 0
+    z: float = 0
+
+
+@sexp_type('at')
+class AtPos(XYCoord):
+    x: float = 0 # in millimeter
+    y: float = 0 # in millimeter
+    rotation: int = 0  # in degrees, can only be 0, 90, 180 or 270.
+    unlocked: Flag() = True
+
+    def __before_sexp__(self):
+        self.rotation = int(round(self.rotation % 360))
+
+    @property
+    def rotation_rad(self):
+        return math.radians(self.rotation)
+
+    @rotation_rad.setter
+    def rotation_rad(self, value):
+        self.rotation = math.degrees(value)
+
+    def with_rotation(self, angle, cx=0, cy=0):
+        obj = super().with_rotation(angle, cx, cy)
+        return replace(obj, rotation=self.rotation + angle)
+
+
+@sexp_type('font')
+class FontSpec:
+    face: Named(str) = None
+    size: Rename(XYCoord) = field(default_factory=lambda: XYCoord(1.27, 1.27))
+    thickness: Named(float) = None
+    bold: OmitDefault(Named(LegacyCompatibleFlag())) = False
+    italic: OmitDefault(Named(LegacyCompatibleFlag())) = False
+    line_spacing: Named(float) = None
+
+
+@sexp_type('justify')
+class Justify:
+    h: AtomChoice(Atom.left, Atom.right) = None
+    v: AtomChoice(Atom.top, Atom.bottom) = None
+    mirror: Flag() = False
+
+    @property
+    def h_str(self):
+        if self.h is None:
+            return 'center'
+        else:
+            return str(self.h)
+
+    @property
+    def v_str(self):
+        if self.v is None:
+            return 'middle'
+        else:
+            return str(self.v)
+
+
+@sexp_type('effects')
+class TextEffect:
+    font: FontSpec = field(default_factory=FontSpec)
+    justify: OmitDefault(Justify) = field(default_factory=Justify)
+    hide: OmitDefault(Named(LegacyCompatibleFlag())) = False
+
+
+class TextMixin:
+    @property
+    def size(self):
+        return self.effects.font.size.y or 1.27
+
+    @size.setter
+    def size(self, value):
+        self.effects.font.size.x = self.effects.font.size.y = value
+
+    @property
+    def line_width(self):
+        return self.effects.font.thickness or 0.254
+
+    @line_width.setter
+    def line_width(self, value):
+        self.effects.font.thickness = value
+
+    def bounding_box(self, default=None):
+        if not self.text or not self.text.strip():
+            return default
+
+        lines = list(self.render())
+        x1 = min(min(l.x1, l.x2) for l in lines)
+        y1 = min(min(l.y1, l.y2) for l in lines)
+        x2 = max(max(l.x1, l.x2) for l in lines)
+        y2 = max(max(l.y1, l.y2) for l in lines)
+        r = self.effects.font.thickness/2
+        return (x1-r, -(y1-r)), (x2+r, -(y2+r))
+    
+    def svg_path_data(self):
+        for line in self.render():
+            yield f'M {line.x1:.3f} {line.y1:.3f} L {line.x2:.3f} {line.y2:.3f}'
+
+    @property
+    def default_v_align(self):
+        return 'bottom'
+
+    @property
+    def h_align(self):
+        return 'left' if self.effects.justify.h else 'center'
+
+    @property
+    def mirrored(self):
+        return False, False
+
+    def to_svg(self, color='black', variables={}):
+        if not self.effects or self.effects.hide or not self.effects.font:
+            return
+
+        font = Newstroke.load()
+        text = string.Template(self.text).safe_substitute(variables)
+        aperture = ap.CircleAperture(self.line_width or 0.2, unit=MM)
+        rot = self.rotation
+        h_align = self.h_align
+        mx, my = self.mirrored
+        if rot in (90, 270):
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+            rot = (rot+180)%360
+        elif rot == 180:
+            rot = 0
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+
+        if my and rot in (0, 180):
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+            rot = (rot+180)%360
+        if mx and rot in (90, 270):
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+            rot = (rot+180)%360
+        if rot == 180:
+            rot = 0
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+        if rot == 90:
+            rot = 270
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+
+        yield font.render_svg(text,
+                              size=self.size or 1.27,
+                              h_align=h_align,
+                              v_align=self.effects.justify.v or self.default_v_align,
+                              stroke=color,
+                              stroke_width=f'{self.line_width:.3f}',
+                              scale=(1,1),
+                              rotation=0,
+                              transform=f'translate({self.at.x:.3f} {self.at.y:.3f}) rotate({rot})',
+                              )
+
+    @property
+    def _text_offset(self):
+        return (0, 0)
+
+    @property
+    def rotation(self):
+        return self.at.rotation
+
+    def render(self, variables={}):
+        if not self.effects or self.effects.hide or not self.effects.font:
+            return
+
+        font = Newstroke.load()
+        text = string.Template(self.text).safe_substitute(variables)
+        aperture = ap.CircleAperture(self.line_width or 0.2, unit=MM)
+        for stroke in font.render(text, 
+                                  x0=self.at.x, y=self.at.y,
+                                  size=self.size or 1.27,
+                                  h_align=self.effects.justify.h_str,
+                                  v_align=self.effects.justify.v_str,
+                                  rotation=self.at.rotation,
+                                  ):
+
+            points = []
+            for x, y in stroke:
+                x, y = x+offx, y+offy
+                x, y = rotate_point(x, y, math.radians(-rot or 0))
+                x, y = x+self.at.x, y+self.at.y
+                points.append((x, -y))
+
+            for p1, p2 in zip(points[:-1], points[1:]):
+                yield go.Line(*p1, *p2, aperture=aperture, unit=MM)
+
+
+
+@sexp_type('tstamp')
+class Timestamp:
+    value: str = field(default_factory=uuid.uuid4)
+
+    def __deepcopy__(self, memo):
+        return Timestamp()
+
+    def __after_parse__(self, parent):
+        self.value = str(self.value)
+
+    def before_sexp(self):
+        self.value = Atom(str(self.value))
+
+    def bump(self):
+        self.value = uuid.uuid4()
+
+
+@sexp_type('tedit')
+class EditTime:
+    value: str = field(default_factory=time.time)
+
+    def __deepcopy__(self, memo):
+        return EditTime()
+
+    def __after_parse__(self, parent):
+        self.value = int(str(self.value), 16)
+
+    def __before_sexp__(self):
+        self.value = Atom(f'{int(self.value):08X}')
+
+    def bump(self):
+        self.value = time.time()
+
+
+@sexp_type('paper')
+class PageSettings:
+    page_format: str = 'A4'
+    width: float = None
+    height: float = None
+    portrait: Flag() = False
+
+
+@sexp_type('property')
+class Property:
+    key: str = ''
+    value: str = ''
+
+
+@sexp_type('property')
+class DrawnProperty(TextMixin):
+    key: str = None
+    value: str = None
+    id: Named(int) = None
+    at: AtPos = None
+    unlocked: OmitDefault(Named(YesNoAtom())) = True
+    layer: Named(str) = None
+    hide: OmitDefault(Named(YesNoAtom())) = False
+    uuid: UUID = None
+    tstamp: Timestamp = None
+    effects: OmitDefault(TextEffect) = field(default_factory=TextEffect)
+    _ : SEXP_END = None
+    parent: object = None
+
+    def __after_parse(self, parent=None):
+        self.parent = parent
+
+    # Alias value for text mixin
+    @property
+    def text(self):
+        return self.value
+
+    @text.setter
+    def text(self, value):
+        self.value = value
+
+
+@sexp_type('chamfer')
+class Chamfer:
+    top_left: Flag() = False
+    top_right: Flag() = False
+    bottom_left: Flag() = False
+    bottom_right: Flag() = False
+
+
+if __name__ == '__main__':
+    class Foo:
+        pass
+
+    foo = Foo()
+    foo.stroke =  troke(0.01, Atom.dash_dot_dot)
+    d = Dasher(foo)
+    #d = Dasher(Stroke(0.01, Atom.solid))
+    d.move(1, 1)
+    d.line(1, 2)
+    d.line(3, 2)
+    d.line(3, 1)
+    d.close()
+
+    print('<?xml version="1.0" standalone="no"?>')
+    print('<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">')
+    print('<svg version="1.1" width="4cm" height="3cm" viewBox="0 0 4 3" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">')
+    for x1, y1, x2, y2 in d:
+        print(f'<path fill="none" stroke="black" stroke-width="0.01" stroke-linecap="round" d="M {x1},{y1} L {x2},{y2}"/>')
+    print('</svg>')

src/gerbonara/cad/kicad/footprints.py

@@ -0,0 +1,996 @@
+"""
+Library for handling KiCad's footprint files (`*.kicad_mod`).
+"""
+
+import re
+import copy
+import enum
+import string
+import datetime
+import math
+import time
+import fnmatch
+from itertools import chain
+from pathlib import Path
+from dataclasses import field, replace
+
+from .sexp import *
+from .base_types import *
+from .primitives import *
+from . import graphical_primitives as gr
+
+from ..primitives import Positioned
+
+from ... import __version__
+from ... import graphic_primitives as gp
+from ... import graphic_objects as go
+from ... import apertures as ap
+from ...layers import LayerStack
+from ...newstroke import Newstroke
+from ...utils import MM, rotate_point, offset_bounds, sum_bounds
+from ...aperture_macros.parse import GenericMacros, ApertureMacro
+from ...aperture_macros import primitive as amp
+
+
+class _MISSING:
+    pass
+
+def angle_difference(a, b):
+    return (b - a + math.pi) % (2*math.pi) - math.pi
+
+@sexp_type('attr')
+class Attribute:
+    type: AtomChoice(Atom.smd, Atom.through_hole) = None
+    board_only: Flag() = False
+    virtual: Flag() = False # prior to 20208026
+    exclude_from_pos_files: Flag() = False
+    exclude_from_bom: Flag() = False
+    allow_missing_courtyard: Flag() = False
+    allow_soldermask_bridges: Flag() = False
+    dnp: Flag() = False
+
+
+@sexp_type('fp_text')
+class Text:
+    type: AtomChoice(Atom.reference, Atom.value, Atom.user) = Atom.user
+    text: str = ""
+    at: AtPos = field(default_factory=AtPos)
+    unlocked: OmitDefault(Named(YesNoAtom())) = False
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    hide: Flag() = False
+    effects: TextEffect = field(default_factory=TextEffect)
+    tstamp: Timestamp = None
+
+    def render(self, variables={}, cache=None):
+        if self.hide: # why
+            return
+
+        yield from gr.Text.render(self, variables=variables)
+
+
+@sexp_type('fp_text_box')
+class TextBox:
+    locked: Flag() = False
+    text: str = None
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    margins: Rename(gr.Margins) = None
+    pts: PointList = None
+    angle: Named(float) = 0.0
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    effects: TextEffect = field(default_factory=TextEffect)
+    border: Named(YesNoAtom()) = False
+    stroke: Stroke = field(default_factory=Stroke)
+    render_cache: RenderCache = None
+
+    def render(self, variables={}, cache=None):
+        yield from gr.TextBox.render(self, variables=variables)
+
+
+@sexp_type('fp_line')
+class Line:
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    width: Named(float) = None
+    stroke: Stroke = None
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def to_graphical_primitive(self, flip=False):
+        # FIXME flip
+        return gr.Line(self.start, self.end, self.layer, self.width, self.stroke, self.tstamp)
+
+    def render(self, variables=None, cache=None):
+        dasher = Dasher(self)
+        dasher.move(self.start.x, self.start.y)
+        dasher.line(self.end.x, self.end.y)
+
+        for x1, y1, x2, y2 in dasher:
+            yield go.Line(x1, -y1, x2, -y2, aperture=ap.CircleAperture(dasher.width, unit=MM), unit=MM)
+
+
+@sexp_type('fp_rect')
+class Rectangle:
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    width: Named(float) = None
+    stroke: Stroke = None
+    fill: gr.FillMode = None
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def render(self, variables=None, cache=None):
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.end.x, self.end.y
+        x1, x2 = min(x1, x2), max(x1, x2)
+        y1, y2 = min(y1, y2), max(y1, y2)
+        w, h = x2-x1, y2-y1
+
+        if self.fill == Atom.solid:
+            yield go.Region.from_rectangle(x1, -y1, w, h, unit=MM)
+
+        dasher = Dasher(self)
+        dasher.move(x1, y1)
+        dasher.line(x1, y2)
+        dasher.line(x2, y2)
+        dasher.line(x2, y1)
+        dasher.close()
+
+        aperture = ap.CircleAperture(dasher.width, unit=MM)
+        for x1, y1, x2, y2 in dasher:
+            yield go.Line(x1, -y1, x2, -y2, aperture=aperture, unit=MM)
+
+
+@sexp_type('fp_circle')
+class Circle:
+    center: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    width: Named(float) = None
+    stroke: Stroke = None
+    fill: gr.FillMode = None
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def render(self, variables=None, cache=None):
+        x, y = self.center.x, self.center.y
+        r = math.dist((x, y), (self.end.x, self.end.y)) # insane
+
+        dasher = Dasher(self)
+        aperture = ap.CircleAperture(dasher.width or 0, unit=MM)
+
+        circle = go.Arc.from_circle(x, -y, r, aperture=aperture, unit=MM)
+
+        if self.fill == Atom.solid:
+            yield circle.to_region()
+
+        if dasher.solid:
+            yield circle
+
+        else: # pain
+            for line in circle.approximate(): # TODO precision settings
+                dasher.segments.append((line.x1, line.y1, line.x2, line.y2))
+
+            aperture = ap.CircleAperture(dasher.width, unit=MM)
+            for x1, y1, x2, y2 in dasher:
+                yield go.Line(x1, -y1, x2, -y2, aperture=aperture, unit=MM)
+
+
+@sexp_type('fp_arc')
+class Arc:
+    start: Rename(XYCoord) = None
+    mid: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    width: Named(float) = None
+    angle: Named(float) = None
+    stroke: Stroke = None
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def to_graphical_primitive(self, flip=False):
+        # FIXME flip
+        return gr.Arc(self.start, self.mid, self.end, self.layer, self.width, self.stroke, self.tstamp)
+
+    def render(self, variables=None, cache=None):
+        mx, my = self.mid.x, self.mid.y
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.end.x, self.end.y
+        dasher = Dasher(self)
+        aperture = ap.CircleAperture(dasher.width, unit=MM)
+
+        if math.isclose(x1, x2, abs_tol=1e-6) and math.isclose(y1, y2, abs_tol=1e-6):
+            cx = (x1 + mx) / 2
+            cy = (y1 + my) / 2
+            arc = go.Arc(x1, -y1, x2, -y2, cx-x1, -(cy-y1), clockwise=True, aperture=aperture, unit=MM)
+            if dasher.solid:
+                yield arc
+
+            else:
+                # use approximation from graphic object arc class 
+                for line in arc.approximate():
+                    dasher.segments.append((line.x1, line.y1, line.x2, line.y2))
+                
+                for line in dasher:
+                    yield go.Line(x1, -y1, x2, -y2, aperture=ap.CircleAperture(dasher.width, unit=MM), unit=MM)
+
+        else:
+            # https://stackoverflow.com/questions/56224824/how-do-i-find-the-circumcenter-of-the-triangle-using-python-without-external-lib
+            d = 2 * (x1 * (y2 - my) + x2 * (my - y1) + mx * (y1 - y2))
+            cx = ((x1 * x1 + y1 * y1) * (y2 - my) + (x2 * x2 + y2 * y2) * (my - y1) + (mx * mx + my * my) * (y1 - y2)) / d
+            cy = ((x1 * x1 + y1 * y1) * (mx - x2) + (x2 * x2 + y2 * y2) * (x1 - mx) + (mx * mx + my * my) * (x2 - x1)) / d
+
+        # KiCad only has clockwise arcs.
+        arc = go.Arc(x1, -y1, x2, -y2, cx-x1, -(cy-y1), clockwise=True, aperture=aperture, unit=MM)
+        if dasher.solid:
+            yield arc
+
+        else:
+            # use approximation from graphic object arc class 
+            for line in arc.approximate():
+                dasher.segments.append((line.x1, line.y1, line.x2, line.y2))
+            
+            for line in dasher:
+                yield go.Line(x1, -y1, x2, -y2, aperture=ap.CircleAperture(dasher.width, unit=MM), unit=MM)
+
+
+@sexp_type('fp_poly')
+class Polygon:
+    pts: PointList = field(default_factory=list)
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    width: Named(float) = None
+    stroke: Stroke = None
+    fill: gr.FillMode = None
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def render(self, variables=None, cache=None):
+        if len(self.pts) < 2:
+            return
+
+        dasher = Dasher(self)
+        start = self.pts[0]
+        dasher.move(start.x, start.y)
+        for point in self.pts[1:]:
+            dasher.line(point.x, point.y)
+
+        if dasher.width > 0:
+            aperture = ap.CircleAperture(dasher.width, unit=MM)
+            for x1, y1, x2, y2 in dasher:
+                yield go.Line(x1, -y1, x2, -y2, aperture=aperture, unit=MM)
+
+        if self.fill == Atom.solid:
+            yield go.Region([(pt.x, -pt.y) for pt in self.pts], unit=MM)
+
+
+@sexp_type('fp_curve')
+class Curve:
+    pts: PointList = field(default_factory=list)
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    width: Named(float) = None
+    stroke: Stroke = None
+    locked: Flag() = False
+    tstamp: Timestamp = None
+
+    def render(self, variables=None, cache=None):
+        raise NotImplementedError('Bezier rendering is not yet supported. Please raise an issue and provide an example file.')
+
+
+@sexp_type('drill')
+class Drill:
+    oval: Flag() = False
+    diameter: float = 0
+    width: float = None
+    offset: Rename(XYCoord) = None
+
+
+@sexp_type('options')
+class CustomPadOptions:
+    clearance: Named(AtomChoice(Atom.outline, Atom.convexhull)) = Atom.outline
+    anchor: Named(AtomChoice(Atom.rect, Atom.circle)) = Atom.rect
+
+
+@sexp_type('primitives')
+class CustomPadPrimitives:
+    annotation_bboxes: List(gr.AnnotationBBox) = field(default_factory=list)
+    lines: List(gr.Line) = field(default_factory=list)
+    rectangles: List(gr.Rectangle) = field(default_factory=list)
+    circles: List(gr.Circle) = field(default_factory=list)
+    arcs: List(gr.Arc) = field(default_factory=list)
+    polygons: List(gr.Polygon) = field(default_factory=list)
+    curves: List(gr.Curve) = field(default_factory=list)
+    width: Named(float) = None
+    fill: gr.FillMode = True
+
+    def all(self):
+        yield from self.lines
+        yield from self.rectangles
+        yield from self.circles
+        yield from self.arcs
+        yield from self.polygons
+        yield from self.curves
+
+
+@sexp_type('pad')
+class Pad(NetMixin):
+    number: str = None
+    type: AtomChoice(Atom.thru_hole, Atom.smd, Atom.connect, Atom.np_thru_hole) = None
+    shape: AtomChoice(Atom.circle, Atom.rect, Atom.oval, Atom.trapezoid, Atom.roundrect, Atom.custom) = None
+    at: AtPos = field(default_factory=AtPos)
+    locked: Flag() = False
+    size: Rename(XYCoord) = field(default_factory=XYCoord)
+    drill: Drill = None
+    layers: Named(Array(str)) = field(default_factory=list)
+    properties: List(Property) = field(default_factory=list)
+    remove_unused_layers: Named(YesNoAtom()) = False
+    keep_end_layers: Named(YesNoAtom()) = False
+    zone_layer_connections: Named(Array(str)) = field(default_factory=list)
+    uuid: UUID = field(default_factory=UUID)
+    rect_delta: Rename(XYCoord) = None
+    roundrect_rratio: Named(float) = None
+    thermal_bridge_angle: Named(int) = 45
+    thermal_bridge_width: Named(float) = 0.5
+    chamfer_ratio: Named(float) = None
+    chamfer: Chamfer = None
+    net: Net = None
+    tstamp: Timestamp = None
+    pin_function: Named(str) = None
+    pintype: Named(str) = None
+    pinfunction: Named(str) = None
+    teardrops: gr.TeardropSpec = None
+    die_length: Named(float) = None
+    solder_mask_margin: Named(float) = None
+    solder_paste_margin: Named(float) = None
+    solder_paste_margin_ratio: Named(float) = None
+    clearance: Named(float) = None
+    zone_connect: Named(int) = None
+    thermal_width: Named(float) = None
+    thermal_gap: Named(float) = None
+    options: OmitDefault(CustomPadOptions) = None
+    padstack: gr.PadStack = None
+    primitives: OmitDefault(CustomPadPrimitives) = None
+    _: SEXP_END = None
+    footprint: object = field(repr=False, default=None)
+
+    def __after_parse__(self, parent=None):
+        self.layers = unfuck_layers(self.layers)
+
+    def __before_sexp__(self):
+        self.layers = fuck_layers(self.layers)
+
+    @property
+    def abs_pos(self):
+        if self.footprint:
+            px, py, pr = self.footprint.at.x, self.footprint.at.y, self.footprint.at.rotation
+        else:
+            px, py, pr = 0, 0, 0
+
+        x, y = rotate_point(self.at.x, self.at.y, math.radians(pr))
+        return x+px, y+py, self.at.rotation, False
+
+    @property
+    def layer_mask(self):
+        return layer_mask(self.layers)
+
+    def offset(self, x=0, y=0):
+        self.at = self.at.with_offset(x, y)
+
+    def find_connected_footprints(self, **filters):
+        """ Find footprints connected to the same net as this pad """
+        return self.footprint.board.find_footprints(net=self.net.name, **filters)
+
+    def find_same_net(self, include_vias=True):
+        """ Find traces and vias of the same net as this pad. """ 
+        return self.footprint.board.find_traces(self.net.name, include_vias=include_vias)
+
+    def render(self, variables=None, margin=None, cache=None):
+        #if self.type in (Atom.connect, Atom.np_thru_hole):
+        #    return
+        if self.drill and self.drill.offset:
+            ox, oy = rotate_point(self.drill.offset.x, self.drill.offset.y, math.radians(self.at.rotation))
+        else:
+            ox, oy = 0, 0
+
+        cache_key = id(self), margin
+        if cache and cache_key in cache:
+            aperture = cache[cache_key]
+
+        elif cache is not None:
+            aperture = cache[cache_key] = self.aperture(margin)
+
+        else:
+            aperture = self.aperture(margin)
+
+        yield go.Flash(self.at.x+ox, -(self.at.y+oy), aperture, unit=MM)
+
+    def aperture(self, margin=None):
+        rotation = math.radians(self.at.rotation)
+        margin = margin or 0
+
+        if self.shape == Atom.circle:
+            return ap.CircleAperture(self.size.x+2*margin, unit=MM)
+
+        elif self.shape == Atom.rect:
+            if margin > 0:
+                return GenericMacros.rounded_rect(self.size.x+2*margin,
+                                                  self.size.y+2*margin,
+                                                  margin,
+                                                  0, # no hole
+                                                  rotation)
+            else:
+                return ap.RectangleAperture(self.size.x+2*margin, self.size.y+2*margin, unit=MM).rotated(-rotation)
+
+        elif self.shape == Atom.oval:
+            return ap.ObroundAperture(self.size.x+2*margin, self.size.y+2*margin, unit=MM).rotated(-rotation)
+
+        elif self.shape == Atom.trapezoid:
+            # KiCad's trapezoid aperture "rect_delta" param is just weird to the point that I think it's probably
+            # bugged. If you have a size of 2mm by 2mm, and set this param to 1mm, the resulting pad extends past the
+            # original bounding box, and the trapezoid's base and tip length are 3mm and 1mm.
+
+            x, y = self.size.x, self.size.y
+            if self.rect_delta:
+                dx, dy = self.rect_delta.x, self.rect_delta.y
+            else: # RF_Antenna/Pulse_W3011 has trapezoid pads w/o rect_delta, which KiCad renders as plain rects.
+                dx, dy = 0, 0
+
+            if dx != 0:
+                x, y = y, x
+                dy = dx
+                rotation += math.pi/2
+
+            if margin <= 0:
+                # Note: KiCad already uses MM units, so no conversion needed here.
+
+                alpha = math.atan(y / dy) if dy > 0 else 0
+                return GenericMacros.isosceles_trapezoid(x+dy+2*margin*math.cos(alpha),
+                                                         y+2*margin,
+                                                         2*dy,
+                                                         0, # no hole
+                                                         -rotation + math.pi)
+
+            else:
+                return GenericMacros.rounded_isosceles_trapezoid(x+dy,
+                                                                 y,
+                                                                 2*dy,
+                                                                 margin,
+                                                                 0, # no hole
+                                                                 -rotation + math.pi)
+
+        elif self.shape == Atom.roundrect:
+            x, y = self.size.x, self.size.y
+            r = min(x, y) * self.roundrect_rratio
+            if margin > -r:
+                return GenericMacros.rounded_rect(x+2*margin,
+                                                  y+2*margin,
+                                                  r+margin,
+                                                  0, # no hole
+                                                  rotation)
+            else:
+                return ap.RectangleAperture(x+margin, y+margin, unit=MM).rotated(-rotation)
+
+        elif self.shape == Atom.custom:
+            primitives = []
+
+            # One round trip through the Gerbonara APIs, please!
+            for obj in self.primitives.all():
+                for gn_obj in obj.render():
+                    if margin and isinstance(gn_obj, (go.Line, go.Arc)):
+                        gn_obj = replace(gn_obj, aperture=gn_obj.aperture.dilated(margin))
+
+                    if isinstance(gn_obj, go.Region) and margin > 0:
+                        for line in gn_obj.outline_objects(ap.CircleAperture(2*margin, unit=MM)):
+                            primitives += line._aperture_macro_primitives()
+
+                    new_primitives = list(gn_obj._aperture_macro_primitives()) # todo: precision params
+                    primitives += new_primitives
+
+                    # inexact, only works with convex shapes. But whatever, the only other way to do this would require
+                    # an entire polygon clipping/offsetting library. Probably a bad choice to put something this complex
+                    # into a file format.
+                    if isinstance(gn_obj, go.Region) and margin < 0:
+                        for line in gn_obj.outline_objects(ap.CircleAperture(2*margin, unit=MM)):
+                            line.polarity_dark = False
+                            primitives += line._aperture_macro_primitives()
+
+            if self.options:
+                if self.options.anchor == Atom.rect and self.size.x > 0 and self.size.y > 0:
+                    if margin <= 0:
+                        primitives.append(amp.CenterLine(MM, 1, self.size.x+2*margin, self.size.y+2*margin, 0, 0, 0))
+
+                    else: # margin > 0
+                        primitives.append(amp.CenterLine(MM, 1, self.size.x+2*margin, self.size.y, 0, 0, 0))
+                        primitives.append(amp.CenterLine(MM, 1, self.size.x, self.size.y+2*margin, 0, 0, 0))
+                        primitives.append(amp.Circle(MM, 1, 2*margin, -self.size.x/2, -self.size.y/2))
+                        primitives.append(amp.Circle(MM, 1, 2*margin, -self.size.x/2, +self.size.y/2))
+                        primitives.append(amp.Circle(MM, 1, 2*margin, +self.size.x/2, -self.size.y/2))
+                        primitives.append(amp.Circle(MM, 1, 2*margin, +self.size.x/2, +self.size.y/2))
+
+                elif self.options.anchor == Atom.circle and self.size.x > 0:
+                    primitives.append(amp.Circle(MM, 1, self.size.x+2*margin, 0, 0, 0))
+
+            macro = ApertureMacro(primitives=tuple(primitives)).rotated(-rotation)
+            return ap.ApertureMacroInstance(macro, unit=MM)
+
+    def render_drill(self):
+        if not self.drill:
+            return
+
+        plated = self.type != Atom.np_thru_hole
+        if self.drill.oval:
+            dia = self.drill.diameter
+            w = self.drill.width
+
+            if self.drill.offset:
+                ox, oy = self.drill.offset.x, self.drill.offset.y
+            else:
+                ox, oy = 0, 0
+            
+            if w > dia:
+                dx = 0
+                dy = (w-dia)/2
+            else:
+                dx = (dia-w)/2
+                dy = 0
+
+            aperture = ap.ExcellonTool(min(dia, w), plated=plated, unit=MM)
+            l = go.Line(ox-dx, -(oy-dy), ox+dx, -(oy+dy), aperture=aperture, unit=MM) 
+            l.rotate(math.radians(self.at.rotation))
+            l.offset(self.at.x, -self.at.y)
+            yield l
+
+        else:
+            aperture = ap.ExcellonTool(self.drill.diameter, plated=plated, unit=MM)
+            yield go.Flash(self.at.x, -self.at.y, aperture=aperture, unit=MM) 
+
+
+@sexp_type('model')
+class Model:
+    name: str = ''
+    hide: Flag() = False
+    at: Named(XYZCoord) = field(default_factory=XYZCoord)
+    offset: Named(XYZCoord) = field(default_factory=XYZCoord)
+    opacity: Named(float) = None
+    scale: Named(XYZCoord) = field(default_factory=XYZCoord)
+    rotate: Named(XYZCoord) = field(default_factory=XYZCoord)
+
+
+@sexp_type('component_classes')
+class FootprintComponentClasses:
+    classes: List(Named(str, name='class')) = field(default_factory=list)
+
+
+SUPPORTED_FILE_FORMAT_VERSIONS = [20210108, 20211014, 20221018, 20230517]
+@sexp_type('footprint')
+class Footprint:
+    name: str = None
+    _version: Named(int, name='version') = 20221018
+    uuid: UUID = field(default_factory=UUID)
+    generator: Named(str) = Atom.gerbonara
+    generator_version: Named(str) = __version__
+    locked: Flag() = False
+    placed: Flag() = False
+    layer: Named(str) = 'F.Cu'
+    tedit: EditTime = field(default_factory=EditTime)
+    tstamp: Timestamp = None
+    at: AtPos = field(default_factory=AtPos)
+    descr: Named(str) = None
+    tags: Named(str) = None
+    properties: List(DrawnProperty) = field(default_factory=list)
+    component_classes: FootprintComponentClasses = None
+    path: Named(str) = None
+    sheetname: Named(str) = None
+    sheetfile: Named(str) = None
+    autoplace_cost90: Named(float) = None
+    autoplace_cost180: Named(float) = None
+    solder_mask_margin: Named(float) = None
+    solder_paste_margin_ratio: Named(float) = None
+    solder_paste_margin: Named(float) = None
+    solder_paste_ratio: Named(float) = None
+    clearance: Named(float) = None
+    zone_connect: Named(int) = None
+    thermal_width: Named(float) = None
+    thermal_gap: Named(float) = None
+    attributes: Attribute = field(default_factory=Attribute)
+    private_layers: Named(str) = None
+    net_tie_pad_groups: Named(Array(str)) = None
+    texts: List(Text) = field(default_factory=list)
+    text_boxes: List(TextBox) = field(default_factory=list)
+    lines: List(Line) = field(default_factory=list)
+    rectangles: List(Rectangle) = field(default_factory=list)
+    circles: List(Circle) = field(default_factory=list)
+    arcs: List(Arc) = field(default_factory=list)
+    polygons: List(Polygon) = field(default_factory=list)
+    curves: List(Curve) = field(default_factory=list)
+    dimensions: List(gr.Dimension) = field(default_factory=list)
+    pads: List(Pad) = field(default_factory=list)
+    zones: List(Zone) = field(default_factory=list)
+    groups: List(Group) = field(default_factory=list)
+    embedded_fonts: Named(YesNoAtom()) = False
+    models: List(Model) = field(default_factory=list)
+    _ : SEXP_END = None
+    original_filename: str = None
+    board: object = field(repr=False, default=None)
+
+    def __after_parse__(self, parent):
+        for pad in self.pads:
+            pad.footprint = self
+
+    def property_value(self, key, default=_MISSING):
+        for prop in self.properties:
+            if prop.key == key:
+                return prop.value
+
+        if default is not _MISSING:
+            return default
+
+        raise IndexError(f'Footprint has no property named "{key}"')
+
+    def set_property(self, key, value, x=0, y=0, rotation=0, layer='F.Fab', hide=True, effects=None):
+        for prop in self.properties:
+            if prop.key == key:
+                old_value, prop.value = prop.value, value
+                return old_value
+
+        if effects is None:
+            effects = TextEffect()
+
+        self.properties.append(DrawnProperty(key, value, 
+                                             at=AtPos(x, y, rotation, unlocked=True),
+                                             layer=layer,
+                                             hide=hide,
+                                             effects=effects))
+
+    def make_standard_properties(self):
+        if not self.property_value('Reference', None):
+            self.set_property('Reference', 'REF**', 0, 0, 0, 'F.SilkS')
+
+        if not self.property_value('Value', None):
+            self.set_property('Value', self.name or 'VAL**', 0, 0, 0, hide=False)
+
+        if not self.property_value('Footprint', None):
+            self.set_property('Footprint', '', 0, 0, 0)
+
+        if not self.property_value('Datasheet', None):
+            self.set_property('Datasheet', '', 0, 0, 0)
+
+        if not self.property_value('Description', None):
+            self.set_property('Description', self.descr or '', 0, 0, 0)
+
+    def reset_nets(self):
+        for pad in self.pads:
+            pad.reset_net()
+
+    @property
+    def pads_by_number(self):
+        return {(int(pad.number) if pad.number.isnumeric() else pad.number): pad for pad in self.pads if pad.number}
+
+    def find_pads(self, number=None, net=None):
+        for pad in self.pads:
+            if number is not None and pad.number == str(number):
+                yield pad
+            elif isinstance(net, str) and fnmatch.fnmatch(pad.net.name, net):
+                yield pad
+            elif net is not None and pad.net.number == net:
+                yield pad
+
+    def pad(self, number=None, net=None):
+        candidates = list(self.find_pads(number=number, net=net))
+        if not candidates:
+            raise IndexError(f'No such pad "{number or net}"')
+
+        if len(candidates) > 1:
+            raise IndexError(f'Ambiguous pad "{number or net}", {len(candidates)} matching pads.')
+
+        return candidates[0]
+
+    def offset(self, x=0, y=0):
+        self.at = self.at.with_offset(x, y)
+
+    def copy_placement(self, template):
+        # Fix up rotation of pads - KiCad saves each pad's rotation in *absolute* coordinates, not relative to the
+        # footprint. Because we overwrite the footprint's rotation below, we have to first fix all pads to match the
+        # new rotation.
+        self.rotate(math.radians(template.at.rotation - self.at.rotation))
+        self.at = copy.copy(template.at)
+        self.side = template.side
+
+    @property
+    def version(self):
+        return self._version
+
+    @version.setter
+    def version(self, value):
+        if value not in SUPPORTED_FILE_FORMAT_VERSIONS:
+            raise FormatError(f'File format version {value} is not supported. Supported versions are {", ".join(map(str, SUPPORTED_FILE_FORMAT_VERSIONS))}.')
+
+    @property
+    def reference(self):
+        return self.property_value('Reference')
+
+    @reference.setter
+    def reference(self, value):
+        self.set_property('Reference', value)
+
+    @property
+    def parsed_reference(self):
+        ref = self.reference
+        if (m := re.match(r'^.*[^0-9]([0-9]+)$', ref)):
+            return m.group(0), int(m.group(1))
+        else:
+            return ref
+
+    @property
+    def value(self):
+        return self.property_value('Value')
+
+    @value.setter
+    def value(self, value):
+        self.set_property('Value', value)
+
+    def write(self, filename=None):
+        with open(filename or self.original_filename, 'w') as f:
+            f.write(self.serialize())
+
+    def serialize(self):
+        return build_sexp(sexp(type(self), self)[0])
+
+    @classmethod
+    def open_pretty(kls, pretty_dir, fp_name, *args, **kwargs):
+        pretty_dir = Path(pretty_dir) / f'{fp_name}.kicad_mod'
+        return kls.open_mod(pretty_dir / mod_name, *args, **kwargs)
+
+    @classmethod
+    def open_mod(kls, mod_file, *args, **kwargs):
+        return kls.load(Path(mod_file).read_text(), *args, **kwargs, original_filename=mod_file)
+
+    @classmethod
+    def open_system(kls, fp_path):
+        raise NotImplementedError()
+
+    @classmethod
+    def open_download(kls, fp_path):
+        raise NotImplementedError()
+
+    @classmethod
+    def load(kls, data, *args, **kwargs):
+        return kls.parse(data, *args, **kwargs)
+
+    @property
+    def side(self):
+        return 'front' if self.layer == 'F.Cu' else 'back'
+
+    @side.setter
+    def side(self, value):
+        if value not in ('front', 'back'):
+            raise ValueError(f'side must be either "front" or "back", not {side!r}')
+        
+        if self.side != value:
+            self.flip()
+
+    def flip(self):
+        def flip_layer(name):
+            if name.startswith('F.'):
+                return f'B.{name[2:]}'
+            elif name.startswith('B.'):
+                return f'F.{name[2:]}'
+            else:
+                return name
+
+        self.layer = flip_layer(self.layer)
+        for obj in self.objects():
+            if getattr(obj, 'layer', None) is not None:
+                obj.layer = flip_layer(obj.layer)
+
+            if hasattr(obj, 'layers'):
+                obj.layers = [flip_layer(name) for name in obj.layers]
+
+        for obj in chain(self.texts, self.text_boxes):
+            obj.effects.justify.mirror = not obj.effects.justify.mirror
+
+        for obj in self.properties:
+            if obj.layer is not None:
+                obj.effects.justify.mirror = not obj.effects.justify.mirror
+                obj.layer = flip_layer(obj.layer)
+
+    @property
+    def single_sided(self):
+        raise NotImplementedError()
+    
+    def face(self, direction, pad=None, net=None):
+        if not net and not pad:
+            pad = '1'
+
+        candidates = list(self.find_pads(net=net, number=pad))
+        if len(candidates) == 0:
+            raise KeyError(f'Reference pad "{net or pad}" not found.')
+
+        if len(candidates) > 1:
+            raise KeyError(f'Reference pad "{net or pad}" is ambiguous, {len(candidates)} matching pads found.')
+
+        pad = candidates[0]
+        pad_angle = math.atan2(pad.at.y, pad.at.x)
+
+        target_angle = {
+                'right': 0,
+                'top right': math.pi/4,
+                'top': math.pi/2,
+                'top left': 3*math.pi/4,
+                'left': math.pi,
+                'bottom left': -3*math.pi/4,
+                'bottom': -math.pi/2,
+                'bottom right': -math.pi/4}.get(direction, direction)
+        
+        delta = angle_difference(target_angle, pad_angle)
+        adj = round(delta / (math.pi/2)) * math.pi/2
+        self.set_rotation(adj)
+        
+    def rotate(self, angle=None, cx=None, cy=None, **reference_pad):
+        """ Rotate this footprint by the given angle in radians, counter-clockwise. When (cx, cy) are given, rotate
+        around the given coordinates in the global coordinate space. Otherwise rotate around the footprint's origin. """
+        if (cx, cy) != (None, None):
+            x, y = self.at.x-cx, self.at.y-cy
+            self.at.x = math.cos(-angle)*x - math.sin(-angle)*y + cx
+            self.at.y = math.sin(-angle)*x + math.cos(-angle)*y + cy
+
+        self.at.rotation = (self.at.rotation + math.degrees(angle)) % 360
+
+        for pad in self.pads:
+            pad.at.rotation = (pad.at.rotation + math.degrees(angle)) % 360
+
+        for prop in self.properties:
+            if prop.at is not None:
+                prop.at.rotation = (prop.at.rotation + math.degrees(angle)) % 360
+
+        for text in self.texts:
+            text.at.rotation = (text.at.rotation + math.degrees(angle)) % 360
+
+    def set_rotation(self, angle):
+        old_deg = self.at.rotation
+        new_deg = self.at.rotation = -math.degrees(angle)
+        delta = new_deg - old_deg
+
+        for pad in self.pads:
+            pad.at.rotation = (pad.at.rotation + delta) % 360
+
+        for prop in self.properties:
+            if prop.at is not None:
+                prop.at.rotation = (prop.at.rotation + delta) % 360
+
+        for text in self.texts:
+            text.at.rotation = (text.at.rotation + delta) % 360
+
+    def objects(self, text=False, pads=True, groups=True, zones=True):
+        return chain(
+                (self.texts if text else []),
+                (self.text_boxes if text else []),
+                self.lines,
+                self.rectangles,
+                self.circles,
+                self.arcs,
+                self.polygons,
+                self.curves,
+                (self.dimensions if text else []),
+                (self.pads if pads else []),
+                (self.zones if zones else []),
+                self.groups if groups else [])
+
+    def render(self, layer_stack, layer_map=None, x=0, y=0, rotation=0, text=False, flip=False, variables={}, cache=None):
+        x += self.at.x
+        y += self.at.y
+        rotation += math.radians(self.at.rotation)
+
+        if layer_map is None:
+            layer_map = {kc_id: gn_id for kc_id, gn_id in LAYER_MAP_K2G.items() if gn_id in layer_stack}
+
+        for obj in self.objects(pads=False, text=text, zones=False, groups=False):
+            if not (layer := layer_map.get(obj.layer)):
+                continue
+
+            for fe in obj.render(variables=variables):
+                fe.rotate(rotation)
+                fe.offset(x, y, MM)
+                layer_stack[layer].objects.append(fe)
+
+        for obj in self.pads:
+            if self.solder_mask_margin is not None:
+                solder_mask_margin = self.solder_mask_margin
+            elif obj.solder_mask_margin is not None:
+                solder_mask_margin = obj.solder_mask_margin
+            else:
+                solder_mask_margin = None
+
+            if self.solder_paste_margin is not None:
+                solder_paste_margin = self.solder_paste_margin
+            elif obj.solder_paste_margin_ratio is not None:
+                solder_paste_margin = max(obj.size.x, obj.size.y) * obj.solder_paste_margin_ratio
+            elif obj.solder_paste_margin is not None:
+                solder_paste_margin = obj.solder_paste_margin
+            else:
+                solder_paste_margin = None
+
+            for glob in obj.layers or []:
+                for layer in fnmatch.filter(layer_map, glob):
+
+                    if layer.endswith('.Mask'):
+                        margin = solder_mask_margin
+                    elif layer.endswith('.Paste'):
+                        margin = solder_paste_margin
+                    else:
+                        margin = None
+
+                    for fe in obj.render(margin=margin, cache=cache):
+                        fe.rotate(rotation)
+                        fe.offset(x, y, MM)
+                        if isinstance(fe, go.Flash) and fe.aperture:
+                            fe.aperture = fe.aperture.rotated(rotation)
+                        layer_stack[layer_map[layer]].objects.append(fe)
+
+        for obj in self.pads:
+            for fe in obj.render_drill():
+                fe.rotate(rotation)
+                fe.offset(x, y, MM)
+
+                if obj.type == Atom.np_thru_hole:
+                    layer_stack.drill_npth.append(fe)
+                else:
+                    layer_stack.drill_pth.append(fe)
+    
+    def bounding_box(self, unit=MM):
+        if not hasattr(self, '_bounding_box'):
+            stack = LayerStack()
+            self.render(stack, layer_map=None, x=0, y=0, rotation=0, flip=False, text=False, variables={})
+            self._bounding_box = stack.bounding_box(unit)
+        return self._bounding_box
+
+        
+@dataclass
+class FootprintInstance(Positioned):
+    sexp: Footprint = None
+    hide_text: bool = True 
+    reference: str = 'REF**'
+    value: str = None
+    variables: dict = field(default_factory=lambda: {})
+
+    def render(self, layer_stack, cache=None):
+        x, y, rotation, flip= self.abs_pos
+        x, y = MM(x, self.unit), MM(y, self.unit)
+
+        variables = dict(self.variables)
+
+        if self.reference is not None:
+            variables['REFERENCE'] = str(self.reference)
+
+        if self.value is not None:
+            variables['VALUE'] = str(self.value)
+
+        self.sexp.render(layer_stack, layer_map=None,
+                         x=x, y=y, rotation=rotation,
+                         flip=flip,
+                         text=(not self.hide_text),
+                         variables=variables, cache=cache)
+    
+    def bounding_box(self, unit=MM):
+        return offset_bounds(self.sexp.bounding_box(unit), unit(self.x, self.unit), unit(self.y, self.unit))
+
+
+if __name__ == '__main__':
+    import sys
+    from ...layers import LayerStack
+    fp = Footprint.open_mod(sys.argv[1])
+    stack = LayerStack()
+    FootprintInstance(0, 0, fp, unit=MM).render(stack)
+    print(stack.to_pretty_svg())
+    stack.save_to_directory('/tmp/testdir')
+

src/gerbonara/cad/kicad/graphical_primitives.py

@@ -0,0 +1,462 @@
+
+import string
+import math
+import base64
+import textwrap
+
+from .sexp import *
+from .base_types import *
+from .primitives import *
+
+from ... import graphic_objects as go
+from ... import apertures as ap
+from ...newstroke import Newstroke
+from ...utils import rotate_point, MM, arc_bounds
+
+@sexp_type('layer')
+class TextLayer:
+    layer: str = ''
+    knockout: Flag() = False
+
+
+@sexp_type('gr_text')
+class Text(TextMixin, BBoxMixin):
+    locked: Flag() = False
+    text: str = ''
+    at: AtPos = field(default_factory=AtPos)
+    layer: TextLayer = field(default_factory=TextLayer)
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    effects: TextEffect = field(default_factory=TextEffect)
+    render_cache: RenderCache = None
+
+    def offset(self, x=0, y=0):
+        self.at = self.at.with_offset(x, y)
+
+
+@sexp_type('gr_text_box')
+class TextBox(BBoxMixin):
+    locked: Flag() = False
+    text: str = ''
+    start: Named(XYCoord) = None
+    end: Named(XYCoord) = None
+    margins: Margins = None
+    pts: PointList = field(default_factory=list)
+    angle: OmitDefault(Named(float)) = 0.0
+    layer: Named(str) = ""
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    effects: TextEffect = field(default_factory=TextEffect)
+    border: Named(YesNoAtom()) = False
+    stroke: Stroke = field(default_factory=Stroke)
+    render_cache: RenderCache = None
+
+    def render(self, variables={}):
+        text = string.Template(self.text).safe_substitute(variables)
+        if text != self.text:
+            raise ValueError('Rendering of vector font text with variables not yet supported')
+
+        if not render_cache or not render_cache.polygons:
+            raise ValueError('Vector font text with empty render cache')
+
+        for poly in render_cache.polygons:
+            reg = go.Region([(p.x, -p.y) for p in poly.pts], unit=MM)
+
+            if self.stroke:
+                if self.stroke.type not in (None, Atom.default, Atom.solid):
+                    raise ValueError('Dashed strokes are not supported on vector text')
+
+                yield from reg.outline_objects(aperture=ap.CircleAperture(self.stroke.width, unit=MM))
+
+            yield reg
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+
+@sexp_type('gr_line')
+class Line(WidthMixin):
+    locked: Flag() = False
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    angle: Named(float) = None # wat
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def rotate(self, angle, cx=None, cy=None):
+        self.start.x, self.start.y = rotate_point(self.start.x, self.start.y, angle, cx, cy)
+        self.end.x, self.end.y = rotate_point(self.end.x, self.end.y, angle, cx, cy)
+
+    def render(self, variables=None):
+        if self.angle:
+            raise NotImplementedError('Angles on lines are not implemented. Please raise an issue and provide an example file.')
+
+        dasher = Dasher(self)
+        dasher.move(self.start.x, self.start.y)
+        dasher.line(self.end.x, self.end.y)
+
+        for x1, y1, x2, y2 in dasher:
+            yield go.Line(x1, -y1, x2, -y2, aperture=ap.CircleAperture(dasher.width, unit=MM), unit=MM)
+        # FIXME render all primitives using dasher, maybe share code w/ fp_ prefix primitives
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+    def bounding_box(self, unit=MM):
+        x_min, x_max = min(self.start.x, self.end.x), max(self.start.x, self.end.x)
+        y_min, y_max = min(self.start.y, self.end.y), max(self.start.y, self.end.y)
+        w = self.stroke.width if self.stroke else self.width
+        return (x_min-w, y_max-w), (x_max+w, y_max+w)
+
+
+@sexp_type('target')
+class Target(WidthMixin):
+    shape: AtomChoice(Atom.x, Atom.plus) = 'plus'
+    at: AtPos = field(default_factory=AtPos)
+    size: Rename(XYCoord) = field(default_factory=XYCoord)
+    width: Named(float) = None
+    layer: Named(str) = None
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def render(self, variables=None):
+        raise NotImplementedError('Target objects are not implemented yet')
+
+
+@sexp_type('fill')
+class FillMode:
+    # Needed for compatibility with weird files
+    fill: AtomChoice(Atom.solid, Atom.yes, Atom.no, Atom.none) = False
+
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        return obj[1] in (Atom.solid, Atom.yes)
+
+    @classmethod
+    def __sexp__(kls, value):
+        yield [Atom.fill, Atom.solid if value else Atom.none]
+
+@sexp_type('gr_rect')
+class Rectangle(BBoxMixin, WidthMixin):
+    locked: Flag() = False
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: FillMode = False
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def render(self, variables=None):
+        rect = go.Region.from_rectangle(self.start.x, -self.start.y,
+                                       self.end.x-self.start.x, -(self.end.y-self.start.y),
+                                       unit=MM)
+
+        if self.fill:
+            yield rect
+
+        if (w := self.stroke.width if self.stroke else self.width):
+            # FIXME stroke support
+            yield from rect.outline_objects(aperture=ap.CircleAperture(w, unit=MM))
+
+    @property
+    def top_left(self):
+        return ((min(self.start.x, self.end.x), min(self.start.y, self.end.y)),
+                (max(self.start.x, self.end.x), max(self.start.y, self.end.y)))
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+
+@sexp_type('gr_circle')
+class Circle(BBoxMixin, WidthMixin):
+    locked: Flag() = False
+    center: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: FillMode = False
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def render(self, variables=None):
+        r = math.dist((self.center.x, -self.center.y), (self.end.x, -self.end.y))
+        w = self.stroke.width if self.stroke else self.width
+        aperture = ap.CircleAperture(w or 0, unit=MM)
+        arc = go.Arc.from_circle(self.center.x, -self.center.y, r, aperture=aperture, unit=MM)
+
+        if w:
+            # FIXME stroke support
+            yield arc
+
+        if self.fill:
+            yield arc.to_region()
+
+    def offset(self, x=0, y=0):
+        self.center = self.center.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+    def rotate(self, angle, cx=0, cy=0):
+        self.center = self.center.with_rotation(angle, cx, cy)
+        self.end = self.end.with_rotation(angle, cx, cy)
+
+
+@sexp_type('gr_arc')
+class Arc(WidthMixin, BBoxMixin):
+    locked: Flag() = False
+    start: Rename(XYCoord) = None
+    mid: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    angle: Named(float) = None
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    _: SEXP_END = None
+    center: XYCoord = None
+
+    def __post_init__(self):
+        self.start = XYCoord(self.start)
+        self.end = XYCoord(self.end)
+        if self.mid or self.center is None:
+            self.mid = XYCoord(self.mid)
+        elif self.center:
+            self.mid = center_arc_to_kicad_mid(XYCoord(self.center), self.start, self.end)
+            self.center = None
+
+    def render(self, variables=None):
+        if not (w := self.stroke.width if self.stroke else self.width):
+            return
+
+        aperture = ap.CircleAperture(w, unit=MM)
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.end.x, self.end.y
+        (cx, cy), _r, clockwise = kicad_mid_to_center_arc(self.mid, self.start, self.end)
+        yield go.Arc(x1, -y1, x2, -y2, cx-x1, -(cy-y1), aperture=aperture, clockwise=not clockwise, unit=MM)
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.mid = self.mid.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+    def rotate(self, angle, cx=None, cy=None):
+        self.start.x, self.start.y = rotate_point(self.start.x, self.start.y, angle, cx, cy)
+        self.mid.x, self.mid.y = rotate_point(self.mid.x, self.mid.y, angle, cx, cy)
+        self.end.x, self.end.y = rotate_point(self.end.x, self.end.y, angle, cx, cy)
+
+
+@sexp_type('gr_poly')
+class Polygon(BBoxMixin, WidthMixin):
+    pts: ArcPointList = field(default_factory=list)
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: FillMode = True
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def render(self, variables=None):
+        points = []
+        centers = []
+        for point_or_arc in self.pts:
+            if points:
+                centers.append((None, (None, None)))
+
+            if isinstance(point_or_arc, XYCoord):
+                points.append((point_or_arc.x, -point_or_arc.y))
+
+            else: # base_types.Arc
+                points.append((point_or_arc.start.x, -point_or_arc.start.y))
+                points.append((point_or_arc.end.x, -point_or_arc.end.y))
+                (cx, cy), _r, clockwise = kicad_mid_to_center_arc(point_or_arc.mid, point_or_arc.start, point_or_arc.end)
+                centers.append((not clockwise, (cx, -cy)))
+
+        reg = go.Region(points, centers, unit=MM)
+        reg.close()
+        
+        w = self.stroke.width if self.stroke else self.width
+        # FIXME stroke support
+        if w and w >= 0.005:
+            yield from reg.outline_objects(aperture=ap.CircleAperture(w, unit=MM))
+
+        if self.fill:
+            yield reg
+
+    def offset(self, x=0, y=0):
+        self.pts = [pt.with_offset(x, y) for pt in self.pts]
+
+    def rotate(self, angle, cx=0, cy=0):
+        self.pts = [pt.with_rotation(angle, cx, cy) for pt in self.pts]
+
+
+@sexp_type('gr_curve')
+class Curve(BBoxMixin, WidthMixin):
+    locked: Flag() = False
+    pts: PointList = field(default_factory=list)
+    layer: Named(str) = None
+    width: Named(float) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    def render(self, variables=None):
+        raise NotImplementedError('Bezier rendering is not yet supported. Please raise an issue and provide an example file.')
+
+    def offset(self, x=0, y=0):
+        self.pts =[pt.with_offset(x, y) for pt in self.pts]
+
+
+@sexp_type('gr_bbox')
+class AnnotationBBox:
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    width: Named(float) = None
+    fill: FillMode = False
+ 
+    def render(self, variables=None):
+        return []
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+
+@sexp_type('format')
+class DimensionFormat:
+    prefix: Named(str) = None
+    suffix: Named(str) = None
+    units: Named(int) = 2
+    units_format: Named(int) = 1
+    precision: Named(int) = 7
+    override_value: Named(str) = None
+    suppress_zeros: Flag() = False
+    suppress_zeroes: Flag() = False
+    
+
+@sexp_type('style')
+class DimensionStyle:
+    thickness: Named(float) = 0.1
+    arrow_length: Named(float) = 1.27
+    text_position_mode: Named(int) = 0
+    arrow_direction: Named(AtomChoice(Atom.inward, Atom.outward)) = None
+    extension_height: Named(float) = None
+    text_frame: Named(float) = None
+    extension_offset: Named(float) = None
+    keep_text_aligned: Flag() = False
+
+
+@sexp_type('data')
+class Base64Blob:
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        _data, *content = obj
+        for x in content[:10]:
+            print(str(x))
+        return base64.b64decode(''.join(map(str, content)))
+
+    @classmethod
+    def __sexp__(kls, value):
+        encoded = base64.b64encode(value).decode()
+        yield [Atom.data, *textwrap.wrap(encoded, 76)]
+
+
+@sexp_type('image')
+class Image:
+    at: AtPos = field(default_factory=AtPos)
+    scale: Named(float) = None
+    layer: Named(str) = None
+    locked: Flag() = False
+    uuid: UUID = field(default_factory=UUID)
+    data: Base64Blob = ''
+
+    def offset(self, x=0, y=0):
+        self.at = self.at.with_offset(x, y)
+
+
+@sexp_type('dimension')
+class Dimension:
+    value: float = None
+    locked: Flag() = False
+    dimension_type: Named(AtomChoice(Atom.aligned, Atom.leader, Atom.center, Atom.orthogonal, Atom.radial), name='type') = Atom.aligned
+    layer: Named(str) = 'Dwgs.User'
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = field(default_factory=Timestamp)
+    pts: PointList = field(default_factory=list)
+    height: Named(float) = None
+    width: Named(float) = None
+    orientation: Named(int) = None
+    leader_length: Named(float) = None
+    gr_text: Text = None
+    dimension_format: OmitDefault(DimensionFormat) = field(default_factory=DimensionFormat)
+    dimension_style: OmitDefault(DimensionStyle) = field(default_factory=DimensionStyle)
+ 
+    def render(self, variables=None):
+        raise NotImplementedError('Dimension rendering is not yet supported. Please raise an issue.')
+
+    def offset(self, x=0, y=0):
+        self.pts = [pt.with_offset(x, y) for pt in self.pts]
+
+
+@sexp_type('options')
+class PadStackLayerOptions:
+    anchor: AtomChoice(Atom.rect, Atom.circle) = Atom.circle
+
+
+@sexp_type('primitives')
+class PadStackPrimitives:
+    vectors: Rename(Line, name='gr_vector') = field(default_factory=list)
+    lines: List(Line) = field(default_factory=list)
+    bboxes: List(AnnotationBBox) = field(default_factory=list)
+    arcs: List(Arc) = field(default_factory=list)
+    circles: List(Circle) = field(default_factory=list)
+    curves: List(Curve) = field(default_factory=list)
+    polygons:List(Polygon) = field(default_factory=list)
+
+
+@sexp_type('layer')
+class PadStackLayer:
+    layer: str = ''
+    shape: Named(AtomChoice(Atom.circle, Atom.rect, Atom.oval, Atom.trapezoid, Atom.roundrect, Atom.custom)) = Atom.circle
+    size: Rename(XYCoord) = field(default_factory=XYCoord)
+    rect_delta: Rename(XYCoord) = None
+    offset: Rename(XYCoord) = None
+    roundrect_rratio: Named(float) = None
+    chamfer_ratio: Named(float) = None
+    chamfer: Chamfer = None
+    primitives: PadStackPrimitives = None
+    options: PadStackLayerOptions = None
+    thermal_bridge_angle: Named(float) = None
+    thermal_gap: Named(float) = None
+    thermal_bridge_width: Named(float) = None
+    clearance: Named(float) = None
+    zone_connect: Named(int) = None
+
+
+@sexp_type('padstack')
+class PadStack:
+    mode: Named(AtomChoice('front_inner_back', 'custom')) = Atom.front_inner_back
+    layers: List(PadStackLayer) = field(default_factory=list)
+
+
+@sexp_type('teardrops')
+class TeardropSpec:
+    best_length_ratio: Named(float) = 1.0
+    max_length: Named(float) = 2.0
+    best_width_ratio: Named(float) = 1.0
+    max_width: Named(float) = 2.0
+    curve_points: Named(int) = 0
+    filter_ratio: Named(float) = 0.9
+    enabled: Named(YesNoAtom()) = True
+    allow_two_segments: Named(YesNoAtom()) = True
+    prefer_zone_connections: Named(YesNoAtom()) = True
+
+

src/gerbonara/cad/kicad/layer_colors.py

@@ -0,0 +1,70 @@
+
+# Maps KiCad layer IDs to (r, g, b, a) color tuples. R, G, B are ints in [0...255], a is a float in [0...1]
+KICAD_LAYER_COLORS = {
+    'F.Cu': (200, 52,  52,  1),
+    'In1.Cu': (127, 200, 127, 1),
+    'In2.Cu': (206, 125, 44,  1),
+    'In3.Cu': (79,  203, 203, 1),
+    'In4.Cu': (219, 98, 139,  1),
+    'In5.Cu': (167, 165, 198, 1),
+    'In6.Cu': (40,  204, 217, 1),
+    'In7.Cu': (232, 178, 167, 1),
+    'In8.Cu': (242, 237, 161, 1),
+    'In9.Cu': (141, 203, 129, 1),
+    'In10.Cu': (237, 124, 51,  1),
+    'In11.Cu': (91,  195, 235, 1),
+    'In12.Cu': (247, 111, 142, 1),
+    'In13.Cu': (167, 165, 198, 1),
+    'In14.Cu': (40,  204, 217, 1),
+    'In15.Cu': (232, 178, 167, 1),
+    'In16.Cu': (242, 237, 161, 1),
+    'In17.Cu': (237, 124, 51,  1),
+    'In18.Cu': (91,  195, 235, 1),
+    'In19.Cu': (247, 111, 142, 1),
+    'In20.Cu': (167, 165, 198, 1),
+    'In21.Cu': (40,  204, 217, 1),
+    'In22.Cu': (232, 178, 167, 1),
+    'In23.Cu': (242, 237, 161, 1),
+    'In24.Cu': (237, 124, 51,  1),
+    'In25.Cu': (91,  195, 235, 1),
+    'In26.Cu': (247, 111, 142, 1),
+    'In27.Cu': (167, 165, 198, 1),
+    'In28.Cu': (40,  204, 217, 1),
+    'In29.Cu': (232, 178, 167, 1),
+    'In30.Cu': (242, 237, 161, 1),
+    'B.Cu': (77,  127, 196, 1),
+    'B.Adhes': (0,   0, 132,   1),
+    'F.Adhes': (132, 0, 132,   1),
+    'B.Paste': (0,   194, 194, 0.9),
+    'F.Paste': (180, 160, 154, 0.9),
+    'B.SilkS': (232, 178, 167, 1),
+    'F.SilkS': (242, 237, 161, 1),
+    'B.Mask': (2,   255, 238, 0.4),
+    'F.Mask': (216, 100, 255, 0.4),
+    'Dwgs.User': (194, 194, 194, 1),
+    'Cmts.User': (89,  148, 220, 1),
+    'Eco1.User': (180, 219, 210, 1),
+    'Eco2.User': (216, 200, 82,  1),
+    'Edge.Cuts': (208, 210, 205, 1),
+    'Margin': (255, 38,  226, 1),
+    'B.CrtYd': (38,  233,  255, 1),
+    'F.CrtYd': (255, 38,  226, 1),
+    'B.Fab': (88,  93,  132, 1),
+    'F.Fab': (175, 175, 175, 1),
+    'User.1': (194, 194, 194, 1),
+    'User.2': (89,  148, 220, 1),
+    'User.3': (180, 219, 210, 1),
+    'User.4': (216, 200, 82,  1),
+    'User.5': (194, 194, 194, 1),
+    'User.6': (89,  148, 220, 1),
+    'User.7': (180, 219, 210, 1),
+    'User.8': (216, 200, 82,  1),
+    'User.9': (232, 178, 167, 1),
+}
+
+KICAD_DRILL_COLORS = {
+    ('drill', 'pth'): (194, 194, 0, 1),
+    ('drill', 'npth'): (26,  196, 210, 1),
+    ('drill', 'via'): (227, 183, 46, 1),
+}
+

src/gerbonara/cad/kicad/pcb.py

@@ -0,0 +1,848 @@
+"""
+Library for handling KiCad's PCB files (`*.kicad_mod`).
+"""
+
+import math
+from pathlib import Path
+from dataclasses import field, KW_ONLY, fields
+from itertools import chain
+import re
+import fnmatch
+import functools
+
+from .sexp import *
+from .base_types import *
+from .primitives import *
+from .footprints import Footprint, Pad
+from . import graphical_primitives as gr
+import rtree.index
+
+from .. import primitives as cad_pr
+
+from ... import graphic_primitives as gp
+from ... import graphic_objects as go
+from ... import apertures as ap
+from ...layers import LayerStack
+from ...newstroke import Newstroke
+from ...utils import MM, rotate_point
+
+
+def match_filter(f, value):
+    if isinstance(f, str) and re.fullmatch(f, value):
+        return True
+    return value in f
+
+def gn_side_to_kicad(side, layer='Cu'):
+    if side == 'top':
+        return f'F.{layer}'
+    elif side == 'bottom':
+        return f'B.{layer}'
+    elif side.startswith('inner'):
+        return f'In{int(side[5:])}.{layer}'
+    else:
+        raise ValueError(f'Cannot parse gerbonara side name "{side}"')
+
+def gn_layer_to_kicad(layer, flip=False):
+    side = 'B' if flip else 'F'
+    if layer == 'silk':
+        return f'{side}.SilkS'
+    elif layer == 'mask':
+        return f'{side}.Mask'
+    elif layer == 'paste':
+        return f'{side}.Paste'
+    elif layer == 'copper':
+        return f'{side}.Cu'
+    else:
+        raise ValueError('Cannot translate gerbonara layer name "{layer}" to KiCad')
+
+
+@sexp_type('general')
+class GeneralSection:
+    thickness: Named(float) = 1.60
+    legacy_teardrops: Named(YesNoAtom()) = False
+    drawings: Named(int) = None
+    tracks: Named(int) = None
+    zones: Named(int) = None
+    modules: Named(int) = None
+    nets: Named(int) = None
+    links: Named(int) = None
+    no_connects: Named(int) = None
+    area: Named(Array(float)) = None
+
+
+@sexp_type('layers')
+class LayerSettings:
+    index: int = 0
+    canonical_name: str = None
+    layer_type: AtomChoice(Atom.jumper, Atom.mixed, Atom.power, Atom.signal, Atom.user, Atom.auxiliary) = Atom.signal
+    custom_name: str = None
+
+
+@sexp_type('layer')
+class LayerStackupSettings:
+    dielectric: Flag() = False
+    name: str = None
+    index: int = None
+    layer_type: Named(str, name='type') = ''
+    color: Color = None
+    thickness: Named(float) = None
+    material: Named(str) = None
+    epsilon_r: Named(float) = None
+    loss_tangent: Named(float) = None
+
+
+@sexp_type('stackup')
+class StackupSettings:
+    layers: List(LayerStackupSettings) = field(default_factory=list)
+    copper_finish: Named(str) = None
+    dielectric_constraints: Named(YesNoAtom()) = None
+    edge_connector: Named(AtomChoice(Atom.yes, Atom.bevelled)) = None
+    castellated_pads: Named(YesNoAtom()) = None
+    edge_plating: Named(YesNoAtom()) = None
+
+@sexp_type('setup')
+class BoardSetup:
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        return obj
+
+    @classmethod
+    def __sexp__(kls, value):
+        yield value
+
+
+@sexp_type('segment')
+class TrackSegment(BBoxMixin):
+    start: Rename(XYCoord) = field(default_factory=XYCoord)
+    end: Rename(XYCoord) = field(default_factory=XYCoord)
+    width: Named(float) = 0.5
+    locked: Flag() = False
+    layer: Named(str) = 'F.Cu'
+    extra_layers: Named(Array(str), name='layers') = field(default_factory=list)
+    solder_mask_margin: Named(float) = None
+    net: Named(int) = 0
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    @classmethod
+    def from_footprint_line(kls, line, flip=False):
+        # FIXME flip
+        return kls(line.start, line.end, line.width or line.stroke.width, line.layer, line.locked, tstamp=line.tstamp)
+
+    def __post_init__(self):
+        self.start = XYCoord(self.start)
+        self.end = XYCoord(self.end)
+
+    def __after_parse__(self, parent):
+        if self.extra_layers:
+            self.layer, *self.extra_layers = self.extra_layers
+
+    def __before_sexp__(self):
+        if self.extra_layers:
+            self.extra_layers.insert(0, self.layer)
+            self.layer = None
+
+    @property
+    def layer_mask(self):
+        return layer_mask([self.layer])
+
+    def render(self, variables=None, cache=None):
+        if not self.width:
+            return
+
+        aperture = ap.CircleAperture(self.width, unit=MM)
+        yield go.Line(self.start.x, -self.start.y, self.end.x, -self.end.y, aperture=aperture, unit=MM)
+
+    def rotate(self, angle, cx=None, cy=None):
+        if cx is None or cy is None:
+            cx, cy = self.start.x, self.start.y
+
+        self.start.x, self.start.y = rotate_point(self.start.x, self.start.y, angle, cx, cy)
+        self.end.x, self.end.y = rotate_point(self.end.x, self.end.y, angle, cx, cy)
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+
+@sexp_type('arc')
+class TrackArc(BBoxMixin):
+    start: Rename(XYCoord) = field(default_factory=XYCoord)
+    mid: Rename(XYCoord) = field(default_factory=XYCoord)
+    end: Rename(XYCoord) = field(default_factory=XYCoord)
+    width: Named(float) = 0.5
+    layer: Named(str) = 'F.Cu'
+    locked: Flag() = False
+    net: Named(int) = 0
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    _: SEXP_END = None
+    center: XYCoord = None
+
+    def __post_init__(self):
+        self.start = XYCoord(self.start)
+        self.end = XYCoord(self.end)
+        self.mid = XYCoord(self.mid) if self.center is None else center_arc_to_kicad_mid(XYCoord(self.center), self.start, self.end)
+        self.center = None
+
+    @property
+    def layer_mask(self):
+        return layer_mask([self.layer])
+
+    def render(self, variables=None, cache=None):
+        if not self.width:
+            return
+
+        aperture = ap.CircleAperture(self.width, unit=MM)
+        cx, cy = self.mid.x, self.mid.y
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.end.x, self.end.y
+        yield go.Arc(x1, -y1, x2, -y2, cx-x1, -(cy-y1), aperture=aperture, clockwise=True, unit=MM)
+
+    def rotate(self, angle, cx=None, cy=None):
+        self.start.x, self.start.y = rotate_point(self.start.x, self.start.y, angle, cx, cy)
+        self.mid.x, self.mid.y = rotate_point(self.mid.x, self.mid.y, angle, cx, cy)
+        self.end.x, self.end.y = rotate_point(self.end.x, self.end.y, angle, cx, cy)
+
+    def offset(self, x=0, y=0):
+        self.start = self.start.with_offset(x, y)
+        self.mid = self.mid.with_offset(x, y)
+        self.end = self.end.with_offset(x, y)
+
+
+@sexp_type('tenting')
+class Tenting:
+    front: Flag() = False
+    back: Flag() = False
+    none: Flag() = False
+
+
+@sexp_type('via')
+class Via(BBoxMixin):
+    via_type: AtomChoice(Atom.blind, Atom.micro) = None
+    locked: Flag() = False
+    at: Rename(XYCoord) = field(default_factory=XYCoord)
+    size: Named(float) = 0.8
+    drill: Named(float) = 0.4
+    layers: Named(Array(str)) = field(default_factory=lambda: ['F.Cu', 'B.Cu'])
+    teardrops: gr.TeardropSpec = None
+    tenting: Tenting = None
+    padstack: gr.PadStack = None
+    remove_unused_layers: Flag() = False
+    keep_end_layers: Flag() = False
+    free: Named(YesNoAtom()) = False
+    zone_layer_connections: Named(Array(str)) = field(default_factory=list)
+    net: Named(int) = 0
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+
+    @classmethod
+    def from_pad(kls, pad):
+        if pad.type != Atom.thru_hole or pad.shape != Atom.circle:
+            raise ValueError('Can only convert circular through-hole pads to vias.')
+
+        if pad.drill and (pad.drill.oval or pad.drill.offset):
+            raise ValueError('Can only convert pads with centered, circular drills to vias.')
+
+        x, y, rot, _flip = pad.abs_pos
+        return kls(locked=pad.locked,
+                   at=XYCoord(x, y),
+                   size=max(pad.size.x, pad.size.y),
+                   drill=pad.drill.diameter if pad.drill else 0,
+                   layers=[l for l in pad.layers if l.endswith('.Cu')],
+                   free=True,
+                   net=pad.net.number if pad.net else 0,
+                   tstamp=pad.tstamp)
+
+    @property
+    def abs_pos(self):
+        return self.at.x, self.at.y, 0, False
+
+    @property
+    def layer_mask(self):
+        return layer_mask(self.layers)
+
+    @property
+    def width(self):
+        return self.size
+
+    def __post_init__(self):
+        self.at = XYCoord(self.at)
+
+    def render_drill(self):
+        aperture = ap.ExcellonTool(self.drill, plated=True, unit=MM)
+        yield go.Flash(self.at.x, -self.at.y, aperture=aperture, unit=MM) 
+
+    def render(self, variables=None, cache=None):
+        aperture = ap.CircleAperture(self.size, unit=MM)
+        yield go.Flash(self.at.x, -self.at.y, aperture, unit=MM)
+
+    def rotate(self, angle, cx=None, cy=None):
+        if cx is None or cy is None:
+            return
+
+        self.at.x, self.at.y = rotate_point(self.at.x, self.at.y, angle, cx, cy)
+
+    def offset(self, x=0, y=0):
+        self.at = self.at.with_offset(x, y)
+
+
+@sexp_type('net_class')
+class LegacyNetclass:
+    name: str = ''
+    description: str = ''
+    clearance: Named(float) = None
+    trace_width: Named(float) = None
+    via_dia: Named(float) = None
+    via_drill: Named(float) = None
+    uvia_dia: Named(float) = None
+    uvia_drill: Named(float) = None
+    diff_pair_width: Named(float) = None
+    diff_pair_gap: Named(float) = None
+    nets: Rename(List(Named(str)), name='add_net') = field(default_factory=list)
+
+
+@sexp_type('generated')
+class GeneratedPatterns:
+    type: Named(Atom) = ''
+    name: Named(str) = ''
+    layer: Named(str) = ''
+    locked: Flag() = False
+    members: Named(Array(Atom), name='members') = field(default_factory=list)
+    _ : SEXP_END = None
+    params: dict = field(default_factory=dict)
+
+    def __catchall__(self, sexp_value, path=''):
+        key, value = sexp_value
+        self.params[key] = value
+
+    @classmethod
+    def __sexp__(kls, value):
+        return [kls.name_atom,
+             ['type', value.type],
+             ['name', value.name],
+             ['layer', value.layer],
+             ['locked', ('true' if value.locked else 'false')],
+             *[[k, v] for k, v in value.params.items()],
+             ['members', *value.members]]
+
+
+
+SUPPORTED_FILE_FORMAT_VERSIONS = [20200119, 20200512, 20210108, 20211014, 20220621, 20221018, 20230517, 20240706, 20240922, 20241229]
+@sexp_type('kicad_pcb')
+class Board:
+    _version: Named(int, name='version') = 20230517
+    generator: Named(str) = Atom.gerbonara
+    generator_version: Named(str) = Atom.gerbonara
+    legacy_generator: Named(Array(str), name='host') = None
+    general: GeneralSection = None
+    paper: PageSettings = None
+    legacy_page: Rename(PageSettings, 'page') = None
+    title_block: TitleBlock = None
+    layers: Named(Array(Untagged(LayerSettings))) = field(default_factory=list)
+    setup: BoardSetup = field(default_factory=BoardSetup)
+    properties: List(Property) = field(default_factory=list)
+    nets: List(Net) = field(default_factory=list)
+    legacy_netclasses: List(LegacyNetclass) = field(default_factory=list)
+    footprints: List(Footprint) = field(default_factory=list)
+    legacy_footprints: Rename(List(Footprint), 'module') = field(default_factory=list)
+    # Graphical elements
+    texts: List(gr.Text) = field(default_factory=list)
+    text_boxes: List(gr.TextBox) = field(default_factory=list)
+    lines: List(gr.Line) = field(default_factory=list)
+    targets: List(gr.Target) = field(default_factory=list)
+    rectangles: List(gr.Rectangle) = field(default_factory=list)
+    circles: List(gr.Circle) = field(default_factory=list)
+    arcs: List(gr.Arc) = field(default_factory=list)
+    polygons: List(gr.Polygon) = field(default_factory=list)
+    curves: List(gr.Curve) = field(default_factory=list)
+    dimensions: List(gr.Dimension) = field(default_factory=list)
+    images: List(gr.Image) = field(default_factory=list)
+    # Tracks
+    track_segments: List(TrackSegment) = field(default_factory=list)
+    track_arcs: List(TrackArc) = field(default_factory=list)
+    vias: List(Via) = field(default_factory=list)
+    # Other stuff
+    zones: List(Zone) = field(default_factory=list)
+    groups: List(Group) = field(default_factory=list)
+    generated_patterns: List(GeneratedPatterns) = field(default_factory=list)
+    embedded_fonts: Named(YesNoAtom()) = False
+
+    _ : SEXP_END = None
+    original_filename: str = None
+    _trace_index: rtree.index.Index = None
+    _trace_index_map: dict = None
+
+
+    @classmethod
+    def empty_board(kls, inner_layers=0, **kwargs):
+        if 'setup' not in kwargs:
+            kwargs['setup'] = None
+        b = Board(**kwargs)
+        b.init_default_layers(inner_layers)
+        b.__after_parse__(None)
+        return b
+
+
+    def init_default_layers(self, inner_layers=0):
+        inner = [(i, f'In{i}.Cu', 'signal', None) for i in range(1, inner_layers+1)]
+        self.layers = [LayerSettings(idx, name, Atom(ltype)) for idx, name, ltype, cname in [
+            (0, 'F.Cu', 'signal', None),
+            *inner,
+            (31, 'B.Cu', 'signal', None),
+            (32, 'B.Adhes', 'user', 'B.Adhesive'),
+            (33, 'F.Adhes', 'user', 'F.Adhesive'),
+            (34, 'B.Paste', 'user', None),
+            (35, 'F.Paste', 'user', None),
+            (36, 'B.SilkS', 'user', 'B.Silkscreen'),
+            (37, 'F.SilkS', 'user', 'F.Silkscreen'),
+            (38, 'B.Mask', 'user', None),
+            (39, 'F.Mask', 'user', None),
+            (40, 'Dwgs.User', 'user', 'User.Drawings'),
+            (41, 'Cmts.User', 'user', 'User.Comments'),
+            (42, 'Eco1.User', 'user', 'User.Eco1'),
+            (43, 'Eco2.User', 'user', 'User.Eco2'),
+            (44, 'Edge.Cuts', 'user', None),
+            (45, 'Margin', 'user', None),
+            (46, 'B.CrtYd', 'user', 'B.Courtyard'),
+            (47, 'F.CrtYd', 'user', 'F.Courtyard'),
+            (48, 'B.Fab', 'user', None),
+            (49, 'F.Fab', 'user', None),
+            (50, 'User.1', 'auxiliary', None),
+            (51, 'User.2', 'auxiliary', None),
+            (52, 'User.3', 'auxiliary', None),
+            (53, 'User.4', 'auxiliary', None),
+            (54, 'User.5', 'auxiliary', None),
+            (55, 'User.6', 'auxiliary', None),
+            (56, 'User.7', 'auxiliary', None),
+            (57, 'User.8', 'auxiliary', None),
+            (58, 'User.9', 'auxiliary', None)]]
+
+
+    def rebuild_trace_index(self):
+        idx = self._trace_index = rtree.index.Index()
+        id_map = self._trace_index_map = {}
+        for obj in chain(self.track_segments, self.track_arcs):
+            for i, field in enumerate(('start', 'end')):
+                obj_id = id(obj) + i
+                coord = getattr(obj, field)
+                id_map[obj_id] = obj, field, obj.width, obj.layer_mask
+                idx.insert(obj_id, (coord.x, coord.y, coord.x, coord.y))
+
+        for fp in self.footprints:
+            for pad in fp.pads:
+                obj_id = id(pad)
+                id_map[obj_id] = pad, 'at', 0, pad.layer_mask
+                idx.insert(obj_id, (pad.at.x, pad.at.y, pad.at.x, pad.at.y))
+
+        for via in self.vias:
+            obj_id = id(via)
+            id_map[obj_id] = via, 'at', via.size, via.layer_mask
+            idx.insert(obj_id, (via.at.x, via.at.y, via.at.x, via.at.y))
+    
+
+    @staticmethod
+    def _require_trace_index(fun):
+        @functools.wraps(fun)
+        def wrapper(self, *args, **kwargs):
+            if self._trace_index is None:
+                self.rebuild_trace_index()
+
+            return fun(self, *args, **kwargs)
+        return wrapper
+
+
+    @_require_trace_index
+    def query_trace_index_nearest(self, point, layers='*.Cu', n=1):
+        layers = layer_mask(layers)
+
+        x, y = point
+        for obj_id in self._trace_index.nearest((x, y, x, y), n):
+            entry = obj, attr, size, mask = self._trace_index_map[obj_id]
+            if layers & mask:
+                yield entry
+
+
+    @_require_trace_index
+    def query_trace_index_tolerance(self, point, layers='*.Cu', tol=10e-6):
+        layers = layer_mask(layers)
+
+        x, y = point
+        for obj_id in self._trace_index.intersection((x-tol, y-tol, x+tol, y+tol)):
+            entry = obj, attr, size, mask = self._trace_index_map[obj_id]
+            attr = getattr(obj, attr)
+            if layers & mask and math.dist((attr.x, attr.y), (x, y)) <= tol:
+                yield entry
+
+
+    def find_connected_traces(self, obj, layers='*.Cu', tol=10e-6):
+        search_frontier = []
+        visited = set()
+        def enqueue(obj):
+            visited.add(id(obj))
+
+            if isinstance(obj, (TrackSegment, TrackArc)):
+                search_frontier.append((obj.start, obj.width, obj.layer_mask))
+                search_frontier.append((obj.end, obj.width, obj.layer_mask))
+
+            elif isinstance(obj, Via):
+                search_frontier.append((obj.at, obj.size, obj.layer_mask))
+
+            elif isinstance(obj, Pad):
+                search_frontier.append((obj.at, max(obj.size.x, obj.size.y), obj.layer_mask))
+
+            elif isinstance(obj, (Footprint)):
+                for pad in obj.pads:
+                    search_frontier.append((pad.at, max(pad.size.x, pad.size.y), pad.layer_mask))
+
+            else:
+                raise TypeError(f'Finding connected traces for {type(obj)} objects is not (yet) supported.')
+
+        enqueue(obj)
+        yield obj
+
+        filter_layers = layer_mask(layers)
+        while search_frontier:
+            coord, size, layers = search_frontier.pop()
+            x, y = coord.x, coord.y
+
+            # First, find all bounding box intersections
+            found = []
+            for cand, attr, cand_size, cand_mask in self.query_trace_index_tolerance((x, y), layers&filter_layers, size):
+                cand_coord = getattr(cand, attr)
+                dist = math.dist((x, y), (cand_coord.x, cand_coord.y))
+                if dist <= size/2 + cand_size/2 and layers&cand_mask:
+                    found.append((dist, cand))
+
+            if not found:
+                continue
+
+            # Second, filter to match only objects that are within tolerance of closest
+            min_dist = min(e[0] for e in found)
+            for dist, cand in found:
+                if dist < min_dist+tol and id(cand) not in visited:
+                    enqueue(cand)
+                    yield cand
+
+
+    def __after_parse__(self, parent):
+        self.properties = {prop.key: prop.value for prop in self.properties}
+
+        for fp in self.footprints:
+            fp.board = self
+
+        self.nets = {net.index: net.name for net in self.nets}
+        if self.legacy_page:
+            self.paper, self.legacy_page = self.legacy_page, None
+
+
+    def __before_sexp__(self):
+        self.properties = [Property(key, value) for key, value in self.properties.items()]
+        self.nets = [Net(index, name) for index, name in self.nets.items()]
+
+
+    def remove(self, obj):
+        match obj:
+            case gr.Text():
+                self.texts.remove(obj)
+            case gr.TextBox():
+                self.text_boxes.remove(obj)
+            case gr.Line():
+                self.lines.remove(obj)
+            case gr.Rectangle():
+                self.rectangles.remove(obj)
+            case gr.Circle():
+                self.circles.remove(obj)
+            case gr.Arc():
+                self.arcs.remove(obj)
+            case gr.Polygon():
+                self.polygons.remove(obj)
+            case gr.Curve():
+                self.curves.remove(obj)
+            case gr.Dimension():
+                self.dimensions.remove(obj)
+            case gr.Image():
+                self.images.remove(obj)
+            case TrackSegment():
+                self.track_segments.remove(obj)
+            case TrackArc():
+                self.track_arcs.remove(obj)
+            case Via():
+                self.vias.remove(obj)
+            case Zone():
+                self.zones.remove(obj)
+            case Group():
+                self.groups.remove(obj)
+            case Footprint():
+                self.footprints.remove(obj)
+            case _:
+                raise TypeError('Can only remove KiCad objects, cannot map generic gerbonara.cad objects for removal')
+
+
+    def remove_many(self, iterable):
+        iterable = {id(obj) for obj in iterable}
+        for field in fields(self):
+            if field.default_factory is list and field.name not in ('nets', 'properties'):
+                setattr(self, field.name, [obj for obj in getattr(self, field.name) if id(obj) not in iterable])
+
+
+    def add(self, obj):
+        match obj:
+            case gr.Text():
+                self.texts.append(obj)
+            case gr.TextBox():
+                self.text_boxes.append(obj)
+            case gr.Line():
+                self.lines.append(obj)
+            case gr.Rectangle():
+                self.rectangles.append(obj)
+            case gr.Circle():
+                self.circles.append(obj)
+            case gr.Arc():
+                self.arcs.append(obj)
+            case gr.Polygon():
+                self.polygons.append(obj)
+            case gr.Curve():
+                self.curves.append(obj)
+            case gr.Dimension():
+                self.dimensions.append(obj)
+            case gr.Image():
+                self.images.append(obj)
+            case TrackSegment():
+                self.track_segments.append(obj)
+            case TrackArc():
+                self.track_arcs.append(obj)
+            case Via():
+                self.vias.append(obj)
+            case Zone():
+                self.zones.append(obj)
+            case Group():
+                self.groups.append(obj)
+            case Footprint():
+                self.footprints.append(obj)
+                obj.board = self
+            case _:
+                for elem in self.map_gn_cad(obj):
+                    self.add(elem)
+
+
+    def map_gn_cad(self, obj, locked=False, net_name=None):
+        match obj:
+            case cad_pr.Trace():
+                for elem in obj.to_graphic_objects():
+                    elem.convert_to(MM)
+                    match elem:
+                        case go.Arc(x1, y1, x2, y2, xc, yc, cw, ap):
+                            yield TrackArc(
+                                start=XYCoord(x1, y1),
+                                mid=XYCoord(x1+xc, y1+yc),
+                                end=XYCoord(x2, y2),
+                                width=ap.equivalent_width(MM),
+                                layer=gn_side_to_kicad(obj.side),
+                                locked=locked, 
+                                net=self.net_id(net_name))
+
+                        case go.Line(x1, y1, x2, y2, ap):
+                            yield TrackSegment(
+                                start=XYCoord(x1, y1),
+                                end=XYCoord(x2, y2),
+                                width=ap.equivalent_width(MM),
+                                layer=gn_side_to_kicad(obj.side),
+                                locked=locked,
+                                net=self.net_id(net_name))
+
+            case cad_pr.Via(pad_stack=cad_pr.ThroughViaStack(hole, dia, unit=st_unit)):
+                x, y, _a, _f = obj.abs_pos
+                x, y = MM(x, st_unit), MM(y, obj.unit)
+                yield Via(
+                    locked=locked,
+                    at=XYCoord(x, y),
+                    size=MM(dia, st_unit),
+                    drill=MM(hole, st_unit),
+                    layers='*.Cu',
+                    net=self.net_id(net_name))
+
+            case cad_pr.Text(_x, _y, text, font_size, stroke_width, h_align, v_align, layer, dark):
+                x, y, a, flip = obj.abs_pos
+                x, y = MM(x, st_unit), MM(y, st_unit)
+                size = MM(size, unit)
+                yield gr.Text(
+                    text, 
+                    AtPos(x, y, -math.degrees(a)),
+                    layer=gr.TextLayer(gn_layer_to_kicad(layer, flip), not dark),
+                    effects=TextEffect(font=FontSpec(
+                            size=XYCoord(size, size),
+                            thickness=stroke_width),
+                        justify=Justify(h=Atom(h_align) if h_align != 'center' else None,
+                                        v=Atom(v_align) if v_align != 'middle' else None,
+                                        mirror=flip)))
+
+
+    def unfill_zones(self):
+        for zone in self.zones:
+            zone.unfill()
+
+
+    def find_pads(self, net=None):
+        for fp in self.footprints:
+            for pad in fp.pads:
+                if net and not match_filter(net, pad.net.name):
+                    continue
+                yield pad
+
+
+    def find_footprints(self, value=None, reference=None, name=None, net=None, sheetname=None, sheetfile=None):
+        for fp in self.footprints:
+            if name and not match_filter(name, fp.name):
+                continue
+            if value and not match_filter(value, fp.value):
+                continue
+            if reference and not match_filter(reference, fp.reference):
+                continue
+            if net and not any(pad.net and match_filter(net, pad.net.name) for pad in fp.pads):
+                continue
+            if sheetname and not match_filter(sheetname, fp.sheetname):
+                continue
+            if sheetfile and not match_filter(sheetfile, fp.sheetfile):
+                continue
+            yield fp
+
+
+    def find_traces(self, net=None, include_vias=True):
+        net_id = self.net_id(net, create=False)
+        match = lambda obj: obj.net == net_id
+        for obj in chain(self.track_segments, self.track_arcs, self.vias):
+            if obj.net == net_id:
+                yield obj
+
+
+    @property
+    def version(self):
+        return self._version
+
+
+    @version.setter
+    def version(self, value):
+        if value not in SUPPORTED_FILE_FORMAT_VERSIONS:
+            raise FormatError(f'File format version {value} is not supported. Supported versions are {", ".join(map(str, SUPPORTED_FILE_FORMAT_VERSIONS))}.')
+
+
+    def write(self, filename=None):
+        with open(filename or self.original_filename, 'w') as f:
+            f.write(self.serialize())
+
+
+    def serialize(self):
+        return build_sexp(sexp(type(self), self)[0])
+
+
+    @classmethod
+    def open(kls, pcb_file, *args, **kwargs):
+        return kls.load(Path(pcb_file).read_text(), *args, **kwargs, original_filename=pcb_file)
+
+
+    @classmethod
+    def load(kls, data, *args, **kwargs):
+        return kls.parse(data, *args, **kwargs)
+
+
+    @property
+    def single_sided(self):
+        raise NotImplementedError()
+
+
+    def net_id(self, name, create=True):
+        if name is None:
+            return None
+
+        for i, n in self.nets.items():
+            if n == name:
+                return i
+
+        if create:
+            index = max(self.nets.keys()) + 1
+            self.nets[index] = name
+            return index
+
+        else:
+            raise IndexError(f'No such net: "{name}"')
+
+
+# FIXME vvv
+    def graphic_objects(self, text=False, images=False):
+        return chain(
+                (self.texts if text else []),
+                (self.text_boxes if text else []),
+                self.lines,
+                self.rectangles,
+                self.circles,
+                self.arcs,
+                self.polygons,
+                self.curves,
+                (self.dimensions if text else []),
+                (self.images if images else []))
+
+
+    def tracks(self, vias=True):
+        return chain(self.track_segments, self.track_arcs, (self.vias if vias else []))
+
+
+    def objects(self, vias=True, text=False, images=False):
+        return chain(self.graphic_objects(text=text, images=images), self.tracks(vias=vias), self.footprints, self.zones, self.groups)
+
+
+    def render(self, layer_stack, layer_map, x=0, y=0, rotation=0, text=False, flip=False, variables={}, cache=None):
+        for obj in self.objects(images=False, vias=False, text=text):
+            if not (layer := layer_map.get(obj.layer)):
+                continue
+
+            for fe in obj.render(variables=variables):
+                fe.rotate(rotation)
+                fe.offset(x, -y, MM)
+                layer_stack[layer].objects.append(fe)
+
+        for obj in self.vias:
+            for glob in obj.layers or []:
+                for layer in fnmatch.filter(layer_map, glob):
+                    for fe in obj.render(cache=cache):
+                        fe.rotate(rotation)
+                        fe.offset(x, -y, MM)
+                        fe.aperture = fe.aperture.rotated(rotation)
+                        layer_stack[layer_map[layer]].objects.append(fe)
+
+            for fe in obj.render_drill():
+                fe.rotate(rotation)
+                fe.offset(x, -y, MM)
+                layer_stack.drill_pth.append(fe)
+
+@dataclass
+class BoardInstance(cad_pr.Positioned):
+    sexp: Board = None
+    variables: dict = field(default_factory=lambda: {})
+
+    def render(self, layer_stack, cache=None):
+        x, y, rotation, flip = self.abs_pos
+        x, y = MM(x, self.unit), MM(y, self.unit)
+
+        variables = dict(self.variables)
+
+        layer_map = {kc_id: gn_id for kc_id, gn_id in LAYER_MAP_K2G.items() if gn_id in layer_stack}
+
+        self.sexp.render(layer_stack, layer_map,
+                         x=x, y=y, rotation=rotation,
+                         flip=flip,
+                         variables=variables, cache=cache)
+    
+    def bounding_box(self, unit=MM):
+        return offset_bounds(self.sexp.bounding_box(unit), unit(self.x, self.unit), unit(self.y, self.unit))
+
+
+if __name__ == '__main__':
+    import sys
+    from ...layers import LayerStack
+    fp = Board.open(sys.argv[1])
+    stack = LayerStack()
+    BoardInstance(0, 0, fp, unit=MM).render(stack)
+    print(stack.to_pretty_svg())
+    stack.save_to_directory('/tmp/testdir')
+

src/gerbonara/cad/kicad/primitives.py

@@ -0,0 +1,267 @@
+
+import enum
+import math
+import re
+
+from .sexp import *
+from .base_types import *
+
+
+def unfuck_layers(layers):
+    if layers and layers[0] == 'F&B.Cu':
+        return ['F.Cu', 'B.Cu', *layers[1:]]
+    else:
+        return layers
+
+
+def fuck_layers(layers):
+    if layers and 'F.Cu' in layers and 'B.Cu' in layers and not any(re.match(r'^In[0-9]+\.Cu$', l) for l in layers):
+        return ['F&B.Cu', *(l for l in layers if l not in ('F.Cu', 'B.Cu'))]
+    else:
+        return layers
+
+
+def layer_mask(layers):
+    if isinstance(layers, int):
+        return layers
+
+    if isinstance(layers, str):
+        layers = [l.strip() for l in layers.split(',')]
+
+    mask = 0
+    for layer in layers:
+        match layer:
+            case '*.Cu':
+                return 0xffffffff
+            case 'F.Cu':
+                mask |= 1<<0
+            case 'B.Cu':
+                mask |= 1<<31
+            case _:
+                if (m := re.match(fr'In([0-9]+)\.Cu', layer)):
+                    mask |= 1<<int(m.group(1))
+    return mask
+
+
+def center_arc_to_kicad_mid(center, start, end):
+    # Convert normal p1/p2/center notation to the insanity that is kicad's midpoint notation
+    cx, cy = center.x, center.y
+    x1, y1 = start.x - cx, start.y - cy
+    x2, y2 = end.x - cx, end.y - cy
+    # Get a vector pointing from the center to the "mid" point.
+    dx, dy = x1 - x2, y1 - y2 # Get a vector pointing from "end" to "start"
+    dx, dy = -dy, dx # rotate by 90 degrees counter-clockwise
+    # normalize vector, and multiply by radius to get final point
+    r = math.hypot(x1, y1)
+    l = math.hypot(dx, dy)
+    mx = cx + dx / l * r
+    my = cy + dy / l * r
+    return XYCoord(mx, my)
+
+
+def kicad_mid_to_center_arc(mid, start, end):
+    """ Convert kicad's slightly insane midpoint notation to standrad center/p1/p2 notation.
+
+    returns a ((center_x, center_y), radius, clockwise) tuple in KiCad coordinates.
+
+    Returns the center and radius of the circle passing the given 3 points.
+    In case the 3 points form a line, raises a ValueError.
+    """
+    # https://stackoverflow.com/questions/28910718/give-3-points-and-a-plot-circle
+    p1, p2, p3 = start, mid, end
+
+    temp = p2[0] * p2[0] + p2[1] * p2[1]
+    bc = (p1[0] * p1[0] + p1[1] * p1[1] - temp) / 2
+    cd = (temp - p3[0] * p3[0] - p3[1] * p3[1]) / 2
+    det = (p1[0] - p2[0]) * (p2[1] - p3[1]) - (p2[0] - p3[0]) * (p1[1] - p2[1])
+
+    if abs(det) < 1.0e-6:
+        raise ValueError()
+
+    # Center of circle
+    cx = (bc*(p2[1] - p3[1]) - cd*(p1[1] - p2[1])) / det
+    cy = ((p1[0] - p2[0]) * cd - (p2[0] - p3[0]) * bc) / det
+
+    radius = math.sqrt((cx - p1[0])**2 + (cy - p1[1])**2)
+    return (cx, cy), radius, det < 0
+
+
+@sexp_type('hatch')
+class Hatch:
+    style: AtomChoice(Atom.none, Atom.edge, Atom.full) = Atom.edge
+    pitch: float = 0.5
+
+
+@sexp_type('connect_pads')
+class PadConnection:
+    type: AtomChoice(Atom.yes, Atom.thru_hole_only, Atom.full, Atom.no) = None
+    clearance: Named(float) = 0
+
+
+@sexp_type('keepout')
+class ZoneKeepout:
+    tracks_allowed:     Named(YesNoAtom(yes=Atom.allowed, no=Atom.not_allowed), name='tracks')       = True
+    vias_allowed:       Named(YesNoAtom(yes=Atom.allowed, no=Atom.not_allowed), name='vias')         = True
+    pads_allowed:       Named(YesNoAtom(yes=Atom.allowed, no=Atom.not_allowed), name='pads')         = True
+    copperpour_allowed: Named(YesNoAtom(yes=Atom.allowed, no=Atom.not_allowed), name='copperpour')   = True
+    footprints_allowed: Named(YesNoAtom(yes=Atom.allowed, no=Atom.not_allowed), name='footprints')   = True
+
+
+@sexp_type('smoothing')
+class ZoneSmoothing:
+    style: AtomChoice(Atom.chamfer, Atom.fillet) = Atom.chamfer
+    radius: Named(float) = None
+
+
+@sexp_type('fill')
+class ZoneFill:
+    yes: Flag() = False
+    mode: Named(Flag(atom=Atom.hatch)) = False
+    thermal_gap: Named(float) = 0.508
+    thermal_bridge_width: Named(float) = 0.508
+    smoothing: ZoneSmoothing = None
+    radius: Named(float) = 0.125
+    island_removal_mode: Named(int) = None
+    island_area_min: Named(float) = None
+    hatch_thickness: Named(float) = None
+    hatch_gap: Named(float) = None
+    hatch_orientation: Named(int) = None
+    hatch_smoothing_level: Named(int) = None
+    hatch_smoothing_value: Named(float) = None
+    hatch_border_algorithm: Named(AtomChoice(Atom.hatch_thickness, Atom.min_thickness)) = None
+    hatch_min_hole_area: Named(float) = None
+
+
+@sexp_type('filled_polygon')
+class FillPolygon:
+    layer: Named(str) = ""
+    island: Wrap(Flag()) = False
+    pts: ArcPointList = field(default_factory=list)
+
+
+@sexp_type('fill_segments')
+class FillSegment:
+    layer: Named(str) = ""
+    pts: ArcPointList = field(default_factory=list)
+
+
+@sexp_type('polygon')
+class ZonePolygon:
+    pts: ArcPointList = field(default_factory=list)
+
+
+@sexp_type('placement')
+class ZonePlacement:
+    enabled: Named(YesNoAtom()) = False
+    sheetname: Named(str) = ''
+
+
+@sexp_type('teardrop')
+class ZoneTeardropSpec:
+    type: Named(AtomChoice(Atom.padvia, Atom.track_end)) = Atom.padvia
+
+
+@sexp_type('attr')
+class ZoneAttr:
+    teardrop: ZoneTeardropSpec = None
+
+
+@sexp_type('zone')
+class Zone:
+    locked: Flag() = False
+    net: Named(int) = 0
+    net_name: Named(str) = ""
+    layer: Named(str) = None
+    layers: Named(Array(str)) = None
+    uuid: UUID = field(default_factory=UUID)
+    tstamp: Timestamp = None
+    name: Named(str) = None
+    hatch: Hatch = None
+    priority: OmitDefault(Named(int)) = 0
+    attr: ZoneAttr = None
+    connect_pads: PadConnection = field(default_factory=PadConnection)
+    min_thickness: Named(float) = 0.254
+    filled_areas_thickness: Named(YesNoAtom()) = True
+    keepout: ZoneKeepout = None
+    placement: ZonePlacement = None
+    fill: ZoneFill = field(default_factory=ZoneFill)
+    polygon: ZonePolygon = field(default_factory=ZonePolygon)
+    fill_polygons: List(FillPolygon) = field(default_factory=list)
+    fill_segments: List(FillSegment) = field(default_factory=list)
+
+    def __after_parse__(self, parent=None):
+        self.layers = unfuck_layers(self.layers)
+
+    def __before_sexp__(self):
+        self.layers = fuck_layers(self.layers)
+
+    def unfill(self):
+        self.fill.yes = False
+        self.fill_polygons = []
+        self.fill_segments = []
+
+    def rotate(self, angle, cx=None, cy=None):
+        self.unfill()
+        self.polygon.pts = [pt.with_rotation(angle, cx, cy) for pt in self.polygon.pts]
+
+    def offset(self, x=0, y=0):
+        self.unfill()
+        self.polygon.pts = [pt.with_offset(x, y) for pt in self.polygon.pts]
+
+
+    def bounding_box(self):
+        min_x = min(pt.x for pt in self.polygon.pts)
+        min_y = min(pt.y for pt in self.polygon.pts)
+        max_x = max(pt.x for pt in self.polygon.pts)
+        max_y = max(pt.y for pt in self.polygon.pts)
+        return (min_x, min_y), (max_x, max_y)
+
+
+@sexp_type('polygon')
+class RenderCachePolygon:
+    pts: PointList = field(default_factory=list)
+
+
+@sexp_type('render_cache')
+class RenderCache:
+    text: str = None
+    rotation: int = 0
+    polygons: List(RenderCachePolygon) = field(default_factory=list)
+
+
+@sexp_type('margins')
+class Margins:
+    left: float = 0.0
+    top: float = 0.0
+    right: float = 0.0
+    bottom: float = 0.0
+
+
+@sexp_type('comment')
+class TitleComment:
+    @classmethod
+    def __map__(kls, obj, parent=None, path=''):
+        lines = []
+        for lineno, content in zip(obj[1::2], obj[2::2]):
+            while lineno > len(lines):
+                lines.append('')
+            lines[lineno-1] = content
+
+    @classmethod
+    def __sexp__(kls, value):
+        l = [Atom.comment]
+        for i, line in enumerate(value.splitlines(), start=1):
+            l.append(i)
+            l.append(line.rstrip('\n'))
+        return l
+
+
+@sexp_type('title_block')
+class TitleBlock:
+    title: Named(str) = ''
+    date: Named(str) = ''
+    rev: Named(str) = ''
+    company: Named(str) = ''
+    comment: TitleComment = None
+
+

src/gerbonara/cad/kicad/schematic.py

@@ -0,0 +1,867 @@
+"""
+Library for handling KiCad's schematic files (`*.kicad_sch`).
+"""
+
+import math
+import string
+from pathlib import Path
+from dataclasses import field, KW_ONLY
+from itertools import chain
+import re
+import fnmatch
+import os.path
+import warnings
+
+from .sexp import *
+from .base_types import *
+from .primitives import *
+from .symbols import Symbol
+from . import graphical_primitives as gr
+
+from .. import primitives as cad_pr
+from ... import __version__
+
+from ... import graphic_primitives as gp
+from ... import graphic_objects as go
+from ... import apertures as ap
+from ...layers import LayerStack
+from ...newstroke import Newstroke
+from ...utils import MM, rotate_point, Tag, setup_svg
+from .schematic_colors import *
+
+
+KICAD_PAPER_SIZES = {
+    'A5': (210,   148),
+    'A4': (297,   210),
+    'A3': (420,   297),
+    'A2': (594,   420),
+    'A1': (841,   594),
+    'A0': (1189,  841),
+    'A': (11*25.4, 8.5*25.4),
+    'B': (17*25.4, 11*15.4),
+    'C': (22*25.4, 17*25.4),
+    'D': (34*25.4, 22*25.4),
+    'E': (44*25.4, 34*25.4),
+    'USLetter': (11*25.4, 8.5*25.4),
+    'USLegal': (14*25.4, 8.5*25.4),
+    'USLedger': (17*25.4, 11*25.4),
+    }
+
+@sexp_type('path')
+class SheetPath:
+    path: str = '/'
+    page: Named(str) = '1'
+
+
+@sexp_type('junction')
+class Junction:
+    at: Rename(XYCoord) = field(default_factory=XYCoord)
+    diameter: Named(float) = 0
+    color: Color = field(default_factory=lambda: Color(0, 0, 0, 0))
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        r = (self.diameter/2 or 0.5)
+        return (self.at.x - r, self.at.y - r), (self.at.x + r, self.at.y + r)
+    
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield Tag('circle', cx=f'{self.at.x:.3f}', cy=f'{self.at.y:.3f}', r=(self.diameter/2 or 0.5),
+                   fill=self.color.svg(colorscheme.wire))
+
+
+@sexp_type('no_connect')
+class NoConnect:
+    at: Rename(XYCoord) = field(default_factory=XYCoord)
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        r = 0.635
+        return (self.at.x - r, self.at.y - r), (self.at.x + r, self.at.y + r)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        r = 0.635
+        x, y = self.at.x, self.at.y
+        yield Tag('path', d=f'M {x-r:.3f} {y-r:.3f} L {x+r:.3f} {y+r:.3f} M {x-r:.3f} {y+r:.3f} L {x+r:.3f} {y-r:.3f}',
+                   fill='none', stroke_width='0.254', stroke=colorscheme.no_connect)
+
+
+@sexp_type('bus_alias')
+class BusAlias:
+    name: str = ''
+    members: Named(Array(str)) = field(default_factory=list)
+
+
+@sexp_type('bus_entry')
+class BusEntry:
+    at: AtPos = field(default_factory=AtPos)
+    size: Rename(XYCoord) = field(default_factory=lambda: XYCoord(2.54, 2.54))
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        r = math.hypot(self.size.x, self.size.y)
+        x1, y1 = self.at.x, self.at.y
+        x2, y2 = rotate_point(x1+r, y1+r, self.at.rotation or 0)
+        x1, x2 = min(x1, x2), max(x1, x2)
+        y1, y2 = min(y1, y2), max(y1, y2)
+
+        r = (self.stroke.width or 0.254) / 2
+        return (x1-r, y1-r), (x2+r, y2+r)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield Tag('path', d='M {self.at.x} {self.at.y} l {self.size.x} {self.size.y}',
+                   transform=f'rotate({self.at.rotation or 0})',
+                   fill='none', stroke=self.stroke.svg_color(colorscheme.bus), width=self.stroke.width or '0.254')
+
+
+def _polyline_svg(self, default_color):
+    da = Dasher(self)
+    if len(self.points.xy) < 2:
+        warnings.warn(f'Schematic {type(self)} with less than two points')
+
+    p0, *rest = self.points.xy
+    da.move(p0.x, p0.y)
+    for pn in rest:
+        da.line(pn.x, pn.y)
+
+    return da.svg(stroke=self.stroke.svg_color(default_color))
+
+
+def _polyline_bounds(self):
+    x1 = min(pt.x for pt in self.points)
+    y1 = min(pt.y for pt in self.points)
+    x2 = max(pt.x for pt in self.points)
+    y2 = max(pt.y for pt in self.points)
+
+    r = (self.stroke.width or 0.254) / 2
+    return (x1-r, y1-r), (x2+r, y2+r)
+
+
+@sexp_type('wire')
+class Wire:
+    points: PointList = field(default_factory=list)
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        return _polyline_bounds(self)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield _polyline_svg(self, colorscheme.wire)
+
+
+@sexp_type('bus')
+class Bus:
+    points: PointList = field(default_factory=list)
+    stroke: Stroke = field(default_factory=Stroke)
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        return _polyline_bounds(self)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield _polyline_svg(self, colorscheme.bus)
+
+
+@sexp_type('polyline')
+class Polyline:
+    points: PointList = field(default_factory=list)
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: OmitDefault(Fill) = None
+    uuid: UUID = field(default_factory=UUID)
+
+    def bounding_box(self, default=None):
+        return _polyline_bounds(self)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield _polyline_svg(self, colorscheme.lines)
+
+
+@sexp_type('circle')
+class Circle:
+    center: Rename(XYCoord) = field(default_factory=XYCoord)
+    radius: Named(float) = 0.0
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: OmitDefault(Fill) = None
+    uuid: UUID = field(default_factory=UUID)
+
+
+@sexp_type('rectangle')
+class Rectangle:
+    start: Rename(XYCoord) = field(default_factory=XYCoord)
+    end: Rename(XYCoord) = field(default_factory=XYCoord)
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: OmitDefault(Fill) = None
+    uuid: UUID = field(default_factory=UUID)
+
+
+def label_shape_path_d(shape, w, h):
+    l, r = {
+        Atom.input: '<]',
+        Atom.output: '[>',
+        Atom.bidirectional: '<>',
+        Atom.tri_state: '<>',
+        Atom.passive: '[]'}.get(shape, '<]')
+    r = h/2
+
+    if l == '[':
+        d = f'M {r:.3f} {r:.3f} L 0 {r:.3f} L 0 {-r:.3f} L {r:.3f} {-r:.3f}'
+    else:
+        d = f'M {r:.3f} {r:.3f} L 0 0 L {r:.3f} {-r:.3f}'
+
+    e = w+r
+    d += f' L {e:.3f} {-r:.3f}'
+
+    if l == '[':
+        return d + f'L {e+r:.3f} {-r:.3f} L {e+r:.3f} {r:.3f} L {e:.3f} {r:.3f} Z'
+    else:
+        return d + f'L {e+r:.3f} {0:.3f} L {e:.3f} {r:.3f} Z'
+
+
+@dataclass
+class TextLabel(TextMixin):
+    text: str = ''
+    shape: Named(AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive, Atom.dot, Atom.round, Atom.diamond, Atom.rectangle)) = Atom.passive
+    exclude_from_sim: Named(YesNoAtom()) = False
+    at: AtPos = field(default_factory=AtPos)
+    fields_autoplaced: Named(YesNoAtom()) = False
+    effects: TextEffect = field(default_factory=TextEffect)
+    uuid: UUID = field(default_factory=UUID)
+    properties: List(DrawnProperty) = field(default_factory=list)
+
+
+@sexp_type('text')
+class Text(TextLabel):
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield from TextMixin.to_svg(self, colorscheme.text)
+
+
+@sexp_type('label')
+class LocalLabel(TextLabel):
+    @property
+    def _text_offset(self):
+        return (0, -2*self.line_width)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield from TextMixin.to_svg(self, colorscheme.labels)
+
+
+@sexp_type('global_label')
+class GlobalLabel(TextLabel):
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        text = super(TextMixin, self).to_svg(colorscheme.labels),
+        text.attrs['transform'] = f'translate({self.size*0.6:.3f} 0)'
+        (x1, y1), (x2, y2) = self.bounding_box()
+        frame = Tag('path', fill='none', stroke_width=0.254, stroke=colorscheme.lines,
+            d=label_shape_path_d(self.shape, self.size*0.2 + y2-y1, self.size*1.2 + 0.254))
+        yield Tag('g', children=[frame, text])
+
+
+@sexp_type('hierarchical_label')
+class HierarchicalLabel(TextLabel):
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        text, = TextMixin.to_svg(self, colorscheme.labels),
+        text.attrs['transform'] = f'translate({self.size*1.2:.3f} 0)'
+        frame = Tag('path', fill='none', stroke_width=0.254, stroke=colorscheme.lines,
+            d=label_shape_path_d(self.shape, self.size, self.size))
+        yield Tag('g', children=[frame, text])
+
+
+@sexp_type('netclass_flag')
+class NetclassFlag(TextLabel):
+    length: Named(float) = 2.54
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        # FIXME
+        yield from TextMixin.to_svg(self, colorscheme.text)
+
+
+@sexp_type('pin')
+class Pin:
+    name: str = '1'
+    uuid: UUID = field(default_factory=UUID)
+    alternate: Named(str) = None
+
+
+# Suddenly, we're doing syntax like this is yaml or something.
+@sexp_type('path')
+class SymbolCrosslinkSheet:
+    path: str = ''
+    reference: Named(str) = ''
+    unit: Named(int) = 1
+    value: OmitDefault(Named(str)) = None
+    footprint: OmitDefault(Named(str)) = None
+
+
+@sexp_type('project')
+class SymbolCrosslinkProject:
+    project_name: str = ''
+    instances: List(SymbolCrosslinkSheet) = field(default_factory=list)
+
+
+@sexp_type('mirror')
+class MirrorFlags:
+    x: Flag() = False
+    y: Flag() = False
+
+
+@sexp_type('property')
+class DrawnProperty(TextMixin):
+    key: str = None
+    value: str = None
+    id: Named(int) = None
+    at: AtPos = field(default_factory=AtPos)
+    hide: Flag() = False
+    effects: TextEffect = field(default_factory=TextEffect)
+    _: SEXP_END = None
+    parent: object = None
+
+    def __after_parse__(self, parent=None):
+        self.parent = parent
+
+    # Alias value for text mixin
+    @property
+    def text(self):
+        if self.key == 'Reference' and self.parent.unit > 0:
+            return f'{self.value}{string.ascii_uppercase[self.parent.unit-1]}'
+        else:
+            return self.value
+
+    @text.setter
+    def text(self, value):
+        self.value = value
+
+    @property
+    def default_v_align(self):
+        return 'middle'
+
+    @property
+    def h_align(self):
+        align = self.effects.justify.h_str
+        if self.rotation in (90, 270):
+            align = {'left': 'right', 'right': 'left'}.get(align, align)
+        return align
+
+    @property
+    def rotation(self):
+        rot = self.at.rotation
+        rot += getattr(self.parent.at, 'rotation', 0)
+        return rot%360
+
+    @property
+    def mirrored(self):
+        if hasattr(self.parent, 'mirror'):
+            return self.parent.mirror.x, self.parent.mirror.y
+        return False, False
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        if not self.hide:
+            yield from TextMixin.to_svg(self, colorscheme.values)
+
+
+@sexp_type('default_instance')
+class DefaultSymbolInstance:
+    reference: Named(str) = ''
+    unit: Named(int) = 1
+    value: Named(str) = ''
+    footprint: Named(str) = ''
+
+
+@sexp_type('symbol')
+class SymbolInstance:
+    name: str = None
+    lib_name: Named(str) = ''
+    lib_id: Named(str) = ''
+    at: AtPos = field(default_factory=AtPos)
+    mirror: OmitDefault(MirrorFlags) = field(default_factory=MirrorFlags)
+    unit: Named(int) = 1
+    exclude_from_sim: Named(YesNoAtom()) = False
+    in_bom: Named(YesNoAtom()) = True
+    on_board: Named(YesNoAtom()) = True
+    dnp: Named(YesNoAtom()) = True
+    fields_autoplaced: Named(YesNoAtom()) = True
+    uuid: UUID = field(default_factory=UUID)
+    default_instance: DefaultSymbolInstance = None
+    properties: List(DrawnProperty) = field(default_factory=list)
+    # AFAICT this property is completely redundant.
+    pins: List(Pin) = field(default_factory=list)
+    # AFAICT this property, too,  is completely redundant. It ultimately just lists paths and references of at most
+    # three other uses of the same symbol in this schematic.
+    instances: Named(Array(SymbolCrosslinkProject)) = field(default_factory=list)
+    _ : SEXP_END = None
+    schematic: object = field(repr=False, default=None)
+
+    def __after_parse__(self, parent):
+        self.schematic = parent
+
+    @property
+    def reference(self):
+        return self['Reference'].value
+
+    @reference.setter
+    def reference(self, value):
+        self['Reference'].value = value
+
+    @property
+    def value(self):
+        return self['Value'].value
+
+    @value.setter
+    def value(self, value):
+        self['Value'].value = value
+
+    @property
+    def footprint(self):
+        return self['Footprint'].value
+
+    @footprint.setter
+    def footprint(self, value):
+        self['Footprint'].value = value
+
+    def __getitem__(self, key):
+        for prop in self.properties:
+            if prop.key == key:
+                return prop
+
+    @property
+    def rotation(self):
+        return self.at.rotation
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        children = []
+        rot = self.at.rotation
+
+        sym = self.schematic.lookup_symbol(self.lib_name, self.lib_id)
+
+        units = [unit for unit in sym.units if unit.unit_global or unit.unit_index == self.unit]
+
+        at_xform = xform = f'translate({self.at.x:.3f} {self.at.y:.3f})'
+        if self.mirror.y:
+            xform += f'scale(-1 -1)'
+        elif self.mirror.x:
+            xform += f'scale(1 1)'
+        else:
+            xform += f'scale(1 -1)'
+        if rot:
+            xform += f'rotate({rot})'
+
+        children = [foo for unit in units for elem in unit.graphical_elements for foo in elem.to_svg(colorscheme)]
+        yield Tag('g', children=children, transform=xform, fill=colorscheme.fill, stroke=colorscheme.lines)
+
+        children = [foo for unit in units for pin in unit.pins for foo in pin.to_svg(colorscheme, self.mirror, rot)]
+        yield Tag('g', children=children, transform=at_xform, fill=colorscheme.fill, stroke=colorscheme.lines)
+
+        for prop in self.properties:
+            yield from prop.to_svg(colorscheme)
+
+
+@sexp_type('path')
+class SubsheetCrosslinkSheet:
+    path: str = ''
+    page: Named(str) = ''
+
+
+@sexp_type('project')
+class SubsheetCrosslinkProject:
+    project_name: str = ''
+    instances: List(SymbolCrosslinkSheet) = field(default_factory=list)
+
+
+@sexp_type('pin')
+class SubsheetPin:
+    name: str = '1'
+    shape: AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive) = Atom.input
+    at: AtPos = field(default_factory=AtPos)
+    effects: TextEffect = field(default_factory=TextEffect)
+    uuid: UUID = field(default_factory=UUID)
+    _ : SEXP_END = None
+    subsheet: object = None
+
+    def __after_parse__(self, parent):
+        self.subsheet = parent
+
+    def to_svg(self):
+        size = self.effects.font.size.y or 1.27
+        yield Tag('path', fill='none', d=label_shape_path_d(self.shape, 0, size+0.5),
+                  transform=f'translate({self.at.x:.3f} {self.at.y:.3f}) rotate({180-self.at.rotation})')
+
+        lx, ly = self.at.x, self.at.y
+        dx, dy = rotate_point(-(size+1), 0, math.radians(self.at.rotation))
+        lx += dx
+        ly += dy
+        frot = self.at.rotation
+        h_align = 'right'
+        if frot == 180:
+            frot = 0
+            h_align = 'left'
+
+        font = Newstroke.load()
+        yield font.render_svg(self.name,
+                              size=size,
+                              x0=0,
+                              y0=0,
+                              h_align=h_align,
+                              v_align='middle',
+                              rotation=-frot,
+                              transform=f'translate({lx:.3f} {ly:.3f})',
+                              scale=(1, 1),
+                              mirror=(False, False),
+                              )
+
+@sexp_type('fill')
+class SubsheetFill:
+    color: Color = field(default_factory=lambda: Color(0, 0, 0, 0))
+
+
+@sexp_type('sheet')
+class Subsheet:
+    at: Rename(XYCoord) = field(default_factory=XYCoord)
+    size: Rename(XYCoord) = field(default_factory=lambda: XYCoord(2.54, 2.54))
+    exclude_from_sim: Named(YesNoAtom()) = False
+    in_bom: Named(YesNoAtom()) = False
+    on_board: Named(YesNoAtom()) = False
+    dnp: Named(YesNoAtom()) = False
+    fields_autoplaced: Named(YesNoAtom()) = True
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: SubsheetFill = field(default_factory=SubsheetFill)
+    uuid: UUID = field(default_factory=UUID)
+    _properties: List(DrawnProperty) = field(default_factory=list)
+    pins: List(SubsheetPin) = field(default_factory=list)
+    # AFAICT this is completely redundant, just like the one in SymbolInstance
+    instances: Named(List(SubsheetCrosslinkProject)) = field(default_factory=list)
+    _ : SEXP_END = None
+    sheet_name: object = field(default_factory=lambda: DrawnProperty('Sheetname', ''))
+    file_name: object = field(default_factory=lambda: DrawnProperty('Sheetfile', ''))
+    schematic: object = field(repr=False, default=None)
+
+    def __after_parse__(self, parent):
+        self.sheet_name, self.file_name, *_extra_params = self._properties
+        self.schematic = parent
+
+    def __before_sexp__(self):
+        self._properties = [self.sheet_name, self.file_name]
+
+    @property
+    def rotation(self):
+        return 0
+
+    def open(self, search_dir=None, safe=True):
+        if search_dir is None:
+            if not self.schematic.original_filename:
+                raise FileNotFoundError('No search path given and path of parent schematic unknown')
+            else:
+                search_dir = Path(self.schematic.original_filename).parent
+        else:
+            search_dir = Path(search_dir)
+
+        resolved = search_dir / self.file_name.value
+        if safe and os.path.commonprefix((search_dir.parts, resolved.parts)) != search_dir.parts:
+                raise ValueError('Subsheet path traversal to parent directory attempted in Subsheet.open(..., safe=True)')
+
+        return Schematic.open(resolved)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        children = []
+
+        for prop in self._properties:
+            yield from prop.to_svg(colorscheme)
+
+        yield Tag('rect', x=f'{self.at.x:.3f}', y=f'{self.at.y:.3f}',
+                  width=f'{self.size.x:.3f}', height=f'{self.size.y:.3f}',
+                  **self.stroke.svg_attrs(colorscheme.lines), fill=self.fill.color.svg(colorscheme.fill))
+
+        children = []
+        for pin in self.pins:
+            children += pin.to_svg()
+
+        #xform = f'translate({self.at.x:.3f} {self.at.y:.3f})'
+        yield Tag('g', children=children, #transform=xform,
+                  fill=self.fill.color.svg(colorscheme.fill),
+                  **self.stroke.svg_attrs(colorscheme.lines))
+
+
+@sexp_type('rule_area')
+class RuleArea:
+    polyline: Polyline = None
+
+
+@sexp_type('text_box')
+class TextBox(TextMixin):
+    text: str = None
+    exclude_from_sim: Named(YesNoAtom()) = False
+    at: AtPos = field(default_factory=AtPos)
+    size: Rename(XYCoord) = None
+    margins: Rename(gr.Margins) = None
+    effects: TextEffect = field(default_factory=TextEffect)
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: OmitDefault(Fill) = None
+    effects: TextEffect = field(default_factory=TextEffect)
+    uuid: UUID = field(default_factory=UUID)
+
+    def render(self, variables={}, cache=None):
+        yield from gr.TextBox.render(self, variables=variables)
+
+
+@sexp_type('lib_symbols')
+class LocalLibrary:
+    symbols: List(Symbol) = field(default_factory=list)
+
+
+SUPPORTED_FILE_FORMAT_VERSIONS = [20230620]
+@sexp_type('kicad_sch')
+class Schematic:
+    _version: Named(int, name='version') = 20230620
+    generator: Named(str) = 'gerbonara'
+    generator_version: Named(str) = __version__
+    legacy_generator: Named(Array(str), name='host') = None
+    uuid: UUID = field(default_factory=UUID)
+    page_settings: PageSettings = field(default_factory=PageSettings)
+    legacy_page: Named(Array(int), name='page') = None
+    legacy_paper: Named(str, name='paper') = None
+    title_block: TitleBlock = None
+    # The doc says this is expected, but eeschema barfs when it's there.
+    # path: SheetPath = field(default_factory=SheetPath)
+    lib_symbols: LocalLibrary = field(default_factory=list)
+    junctions: List(Junction) = field(default_factory=list)
+    no_connects: List(NoConnect) = field(default_factory=list)
+    rule_areas: List(RuleArea) = field(default_factory=list)
+    netclass_flags: List(NetclassFlag) = field(default_factory=list)
+    bus_aliases: List(BusAlias) = field(default_factory=list)
+    bus_entries: List(BusEntry) = field(default_factory=list)
+    wires: List(Wire) = field(default_factory=list)
+    buses: List(Bus) = field(default_factory=list)
+    images: List(gr.Image) = field(default_factory=list)
+    polylines: List(Polyline) = field(default_factory=list)
+    circles: List(Circle) = field(default_factory=list)
+    rectangles: List(Rectangle) = field(default_factory=list)
+    texts: List(Text) = field(default_factory=list)
+    text_boxes: List(TextBox) = field(default_factory=list)
+    local_labels: List(LocalLabel) = field(default_factory=list)
+    global_labels: List(GlobalLabel) = field(default_factory=list)
+    hierarchical_labels: List(HierarchicalLabel) = field(default_factory=list)
+    symbols: List(SymbolInstance) = field(default_factory=list)
+    subsheets: List(Subsheet) = field(default_factory=list)
+    sheet_instances: Named(Array(SubsheetCrosslinkSheet)) = field(default_factory=list)
+    symbol_instances: Named(Array(SymbolCrosslinkProject)) = field(default_factory=list)
+    embedded_fonts: Named(YesNoAtom()) = False
+    _ : SEXP_END = None
+    original_filename: str = None
+
+    @property
+    def version(self):
+        return self._version
+
+    @version.setter
+    def version(self, value):
+        if value not in SUPPORTED_FILE_FORMAT_VERSIONS:
+            raise FormatError(f'File format version {value} is not supported. Supported versions are {", ".join(map(str, SUPPORTED_FILE_FORMAT_VERSIONS))}.')
+
+
+    def lookup_symbol(self, lib_name, lib_id):
+        key = lib_name or lib_id
+        for sym in self.lib_symbols.symbols:
+            if sym.name == key or sym.raw_name == key:
+                return sym
+        raise KeyError(f'Symbol with {lib_name=} {lib_id=} not found')
+
+    def write(self, filename=None):
+        with open(filename or self.original_filename, 'w') as f:
+            f.write(self.serialize())
+
+    def serialize(self):
+        return build_sexp(sexp(type(self), self)[0])
+
+    @classmethod
+    def open(kls, pcb_file, *args, **kwargs):
+        return kls.load(Path(pcb_file).read_text(), *args, **kwargs, original_filename=pcb_file)
+
+    @classmethod
+    def load(kls, data, *args, **kwargs):
+        return kls.parse(data, *args, **kwargs)
+
+    @property
+    def elements(self):
+        yield from self.subsheets
+        yield from self.images
+        yield from self.polylines
+        yield from self.symbols
+        yield from self.junctions
+        yield from self.no_connects
+        yield from self.bus_entries
+        yield from self.wires
+        yield from self.buses
+        yield from self.texts
+        yield from self.local_labels
+        yield from self.global_labels
+        yield from self.hierarchical_labels
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        children = []
+        for elem in self.elements:
+            children += elem.to_svg(colorscheme)
+        w, h = KICAD_PAPER_SIZES[self.page_settings.page_format]
+        return setup_svg(children, ((0, 0), (w, h)), pagecolor=colorscheme.background)
+
+
+    
+# From: https://jakevdp.github.io/blog/2012/10/07/xkcd-style-plots-in-matplotlib/
+#def xkcd_line(x, y, xlim=None, ylim=None, mag=1.0, f1=30, f2=0.05, f3=15):
+def xkcd_line(x, y, xlim=None, ylim=None, mag=1.0, f1=10, f2=0.05, f3=5):
+    """
+    Mimic a hand-drawn line from (x, y) data
+
+    Parameters
+    ----------
+    x, y : array_like
+        arrays to be modified
+    xlim, ylim : data range
+        the assumed plot range for the modification.  If not specified,
+        they will be guessed from the  data
+    mag : float
+        magnitude of distortions
+    f1, f2, f3 : int, float, int
+        filtering parameters.  f1 gives the size of the window, f2 gives
+        the high-frequency cutoff, f3 gives the size of the filter
+    
+    Returns
+    -------
+    x, y : ndarrays
+        The modified lines
+    """
+    import numpy as np
+    from scipy import interpolate, signal
+
+    x = np.asarray(x)
+    y = np.asarray(y)
+    
+    # get limits for rescaling
+    if xlim is None:
+        xlim = (x.min(), x.max())
+    if ylim is None:
+        ylim = (y.min(), y.max())
+
+    if xlim[1] == xlim[0]:
+        xlim = ylim
+        
+    if ylim[1] == ylim[0]:
+        ylim = xlim
+
+    # scale the data
+    x_scaled = (x - xlim[0]) * 1. / (xlim[1] - xlim[0])
+    y_scaled = (y - ylim[0]) * 1. / (ylim[1] - ylim[0])
+
+    # compute the total distance along the path
+    dx = x_scaled[1:] - x_scaled[:-1]
+    dy = y_scaled[1:] - y_scaled[:-1]
+    dist_tot = np.sum(np.sqrt(dx * dx + dy * dy))
+
+    # number of interpolated points is proportional to the distance
+    Nu = int(50 * dist_tot)
+    u = np.arange(-1, Nu + 1) * 1. / (Nu - 1)
+
+    # interpolate curve at sampled points
+    k = min(3, len(x) - 1)
+    res = interpolate.splprep([x_scaled, y_scaled], s=0, k=k)
+    x_int, y_int = interpolate.splev(u, res[0]) 
+
+    # we'll perturb perpendicular to the drawn line
+    dx = x_int[2:] - x_int[:-2]
+    dy = y_int[2:] - y_int[:-2]
+    dist = np.sqrt(dx * dx + dy * dy)
+
+    # create a filtered perturbation
+    coeffs = mag * np.random.normal(0, 0.01, len(x_int) - 2)
+    b = signal.firwin(f1, f2 * dist_tot, window=('kaiser', f3))
+    response = signal.lfilter(b, 1, coeffs)
+
+    x_int[1:-1] += response * dy / dist
+    y_int[1:-1] += response * dx / dist
+
+    # un-scale data
+    x_int = x_int[1:-1] * (xlim[1] - xlim[0]) + xlim[0]
+    y_int = y_int[1:-1] * (ylim[1] - ylim[0]) + ylim[0]
+    
+    return x_int, y_int
+
+def wonkify(path):
+    out = []
+    for segment in path.attrs['d'].split('M')[1:]:
+        if 'A' in segment:
+            out.append(segment)
+            continue
+
+        points = segment.split('L')
+        if points[-1].rstrip().endswith('Z'):
+            closed = True
+            points[-1] = points[-1].rstrip()[:-1].rstrip()
+            points.append(points[0])
+        else:
+            closed = False
+
+        pts = []
+        lx, ly = None, None
+        for pt in points:
+            x, y = pt.strip().split()
+            x, y = float(x), float(y)
+            if (x, y) == (lx, ly):
+                continue
+
+            lx, ly = x, y
+            pts.append((x, y))
+
+        if len(pts) == 2:
+            segs = [pts]
+
+        else:
+            seg = [pts[0]]
+            segs = [seg]
+            for p0, p1, p2 in zip(pts[0::], pts[1::], pts[2::]):
+                dx1, dy1 = p1[0] - p0[0], p1[1] - p0[1]
+                dx2, dy2 = p2[0] - p1[0], p2[1] - p1[1]
+                l1, l2 = math.hypot(dx1, dy1), math.hypot(dx2, dy2)
+                a1, a2 = math.atan2(dy1, dx1), math.atan2(dy2, dx2)
+                da = (a2 - a1 + math.pi) % (2*math.pi) - math.pi
+                if abs(da) > math.pi/4 and l1+l2 > 3:
+                    seg.append(p1)
+                    seg = [p1, p2]
+                    segs.append(seg)
+                seg.append(p1)
+            seg.append(p2)
+
+        for seg in segs:
+            xs, ys = [x for x, y in seg], [y for x, y in seg]
+            xs, ys = xkcd_line(xs, ys)
+            d = ' L '.join(f'{x:.3f} {y:.3f}' for x, y in zip(xs, ys))
+            if closed:
+                d += ' Z'
+            out.append(d)
+
+    path.attrs['d'] = ' '.join(f'M {seg}' for seg in out)
+
+
+def postprocess(tag):
+    if tag.name == 'path':
+        wonkify(tag)
+    else:
+        for child in tag.children:
+            postprocess(child)
+    return tag
+
+if __name__ == '__main__':
+    import sys
+    from ...layers import LayerStack
+    from .tmtheme import *
+    sch = Schematic.open(sys.argv[1])
+    print('Loaded schematic with', len(sch.wires), 'wires and', len(sch.symbols), 'symbols.')
+    for subsh in sch.subsheets:
+        subsh = subsh.open()
+        print('Loaded sub-sheet with', len(subsh.wires), 'wires and', len(subsh.symbols), 'symbols.')
+
+    sch.write('/tmp/test.kicad_sch')
+    for p in Path('/tmp').glob('*.tmTheme'):
+        cs = TmThemeSchematic(p.read_text())
+        Path(f'/tmp/test-{p.stem}.svg').write_text(str(postprocess(sch.to_svg(cs))))
+    for p in Path('/tmp').glob('*.sublime-color-scheme'):
+        cs = SublimeSchematic(p.read_text())
+        Path(f'/tmp/test-{p.stem}.svg').write_text(str(postprocess(sch.to_svg(cs))))
+

src/gerbonara/cad/kicad/schematic_colors.py

@@ -0,0 +1,13 @@
+
+class Colorscheme:
+    class KiCad:
+        wire = 'black'
+        bus = 'black'
+        lines = 'black'
+        no_connect = 'black'
+        text = 'black'
+        values = 'black'
+        labels = 'black'
+        fill = '#cccccc'
+        background = 'white'
+

src/gerbonara/cad/kicad/sexp.py

@@ -0,0 +1,152 @@
+import math
+import re
+import functools
+from typing import Any, Optional
+import uuid
+from dataclasses import dataclass, fields, field
+from copy import deepcopy
+
+
+class SexpError(ValueError):
+    """ Low-level error parsing S-Expression format """ 
+    pass
+
+
+class FormatError(ValueError):
+    """ Semantic error in S-Expression structure """
+    pass
+
+
+class AtomType(type):
+    def __getattr__(cls, key):
+        return cls(key)
+
+
+@functools.total_ordering
+class Atom(metaclass=AtomType):
+    def __init__(self, obj=''):
+        if isinstance(obj, str):
+            self.value = obj
+        elif isinstance(obj, Atom):
+            self.value = obj.value
+        else:
+            raise TypeError(f'Atom argument must be str, not {type(obj)}')
+
+    def __str__(self):
+        return self.value
+
+    def __repr__(self):
+        return f'@{self.value}'
+
+    def __hash__(self):
+        return hash(self.value)
+
+    def __eq__(self, other):
+        if not isinstance(other, (Atom, str)):
+            return self.value == other
+        return self.value == str(other)
+
+    def __lt__(self, other):
+        if not isinstance(other, (Atom, str)):
+            raise TypeError(f'Cannot compare Atom and {type(other)}')
+        return self.value < str(other)
+
+    def __gt__(self, other):
+        if not isinstance(other, (Atom, str)):
+            raise TypeError(f'Cannot compare Atom and {type(other)}')
+        return self.value > str(other)
+
+
+term_regex = r"""(?mx)
+    \s*(?:
+        "((?:\\\\|\\"|[^"])*)"|
+        (\()|
+        (\))|
+        ([+-]?\d+\.\d+(?=[\s\)]))|
+        (\-?\d+(?=[\s\)]))|
+        ([^"\s()][^"\s)]*)
+       )"""
+
+
+def parse_sexp(sexp: str) -> Any:
+    re_iter = re.finditer(term_regex, sexp)
+    rv = list(_parse_sexp_internal(re_iter))
+
+    for leftover in re_iter:
+        quoted_str, lparen, rparen, *rest = leftover.groups()
+        if quoted_str or lparen or any(rest):
+            raise SexpError(f'Leftover garbage after end of expression at position {leftover.start()}')  # noqa: E501
+
+        elif rparen:
+            raise SexpError(f'Unbalanced closing parenthesis at position {leftover.start()}')
+
+    if len(rv) == 0:
+        raise SexpError('No or empty expression')
+
+    if len(rv) > 1:
+        print(rv[0])
+        print(rv[1])
+        raise SexpError('Missing initial opening parenthesis')
+
+    return rv[0]
+
+
+def _parse_sexp_internal(re_iter) -> Any:
+    for match in re_iter:
+        quoted_str, lparen, rparen, float_num, integer_num, bare_str = match.groups()
+
+        if lparen:
+            yield list(_parse_sexp_internal(re_iter))
+        elif rparen:
+            break
+        elif bare_str is not None:
+            yield Atom(bare_str)
+        elif quoted_str is not None:
+            yield quoted_str.replace('\\"', '"')
+        elif float_num:
+            yield float(float_num)
+        elif integer_num:
+            yield int(integer_num)
+
+
+def build_sexp(exp, indent='  ') -> str:
+    # Special case for multi-values
+    if isinstance(exp, (list, tuple)):
+        joined = '('
+        for i, elem in enumerate(exp):
+            if 1 <= i <= 5 and len(joined) < 120 and not isinstance(elem, (list, tuple)):
+                joined += ' '
+            elif i >= 1:
+                joined += '\n' + indent
+            joined += build_sexp(elem, indent=f'{indent}  ')
+        return joined + ')'
+
+    if exp == '':
+        return '""'
+
+    if isinstance(exp, str):
+        exp = exp.replace('"', r'\"')
+        return f'"{exp}"'
+
+    if isinstance(exp, float):
+        # python whyyyy
+        val = f'{exp:.6f}'
+        val = val.rstrip('0')
+        if val[-1] == '.':
+            val += '0'
+        return val
+    else:
+        return str(exp)
+
+
+if __name__ == "__main__":
+    sexp = """ ( ( Winson_GM-402B_5x5mm_P1.27mm data "quoted data" 123 4.5)
+         (data "with \\"escaped quotes\\"")
+         (data (123 (4.5) "(more" "data)")))"""
+
+    print("Input S-expression:")
+    print(sexp)
+    parsed = parse_sexp(sexp)
+    print("\nParsed to Python:", parsed)
+
+    print("\nThen back to: '%s'" % build_sexp(parsed))

src/gerbonara/cad/kicad/sexp_mapper.py

@@ -0,0 +1,404 @@
+
+import textwrap
+
+import copy
+from dataclasses import MISSING, replace, fields
+from .sexp import *
+
+
+SEXP_END = type('SEXP_END', (), {})
+
+
+class AtomChoice:
+    def __init__(self, *choices):
+        self.choices = choices
+
+    def __contains__(self, value):
+        return value in self.choices
+
+    def __atoms__(self):
+        return self.choices
+
+    def __map__(self, obj, parent=None):
+        obj, = obj
+        if obj not in self:
+            raise TypeError(f'Invalid atom {obj} for {type(self)}, valid choices are: {", ".join(map(str, self.choices))}')
+        return obj
+
+    def __sexp__(self, value):
+        yield value
+
+    def __str__(self):
+        choices = '|'.join(map(str, self.choices))
+        return f'AtomChoice({choices})'
+
+
+class Flag:
+    def __init__(self, atom=None, invert=None):
+        self.atom, self.invert = atom, invert
+
+    def __bind_field__(self, field):
+        if self.atom is None:
+            self.atom = Atom(field.name)
+        if self.invert is None:
+            self.invert = bool(field.default)
+
+    def __atoms__(self):
+        return [self.atom]
+
+    def __map__(self, obj, parent=None):
+        return not self.invert
+
+    def __sexp__(self, value):
+        if bool(value) == (not self.invert):
+            yield self.atom
+    
+    def __str__(self):
+        if self.invert is not None:
+            return f'Flag({self.atom}/{self.invert})'
+        return f'Flag({self.atom})'
+
+
+def sexp(t, v):
+    try:
+        if v is None:
+            return []
+        elif t in (int, float, str, Atom):
+            return [t(v)]
+        elif hasattr(t, '__sexp__'):
+            return list(t.__sexp__(v))
+        elif isinstance(t, list):
+            t, = t
+            return [sexp(t, elem) for elem in v]
+        else:
+            raise TypeError(f'Python type {t} of value {v!r} has no defined s-expression serialization')
+
+    except MappingError as e:
+        raise e
+
+    except Exception as e:
+        raise MappingError(f'Error trying to serialize {textwrap.shorten(str(v), width=120)} into type {t}', t, v) from e
+
+
+class MappingError(TypeError):
+    def __init__(self, msg, t, sexp):
+        super().__init__(msg)
+        self.t, self.sexp = t, sexp
+
+def map_sexp(t, v, parent=None, path=''):
+    try:
+        if t is not Atom and hasattr(t, '__map__'):
+            return t.__map__(v, parent=parent)
+
+        elif t in (int, float, str, Atom):
+            v, = v
+            if not isinstance(v, t):
+                types = set({type(v), t})
+                if types == {int, float} or types == {str, Atom}:
+                    v = t(v)
+                else:
+                    raise TypeError(f'Cannot map s-expression value {v} of type {type(v)} to Python type {t}')
+            return v
+
+        elif isinstance(t, list):
+            t, = t
+            return [map_sexp(t, elem, parent=parent, path=f'{path}/{t}') for elem in v]
+
+        else:
+            raise TypeError(f'Python type {t} has no defined s-expression deserialization')
+
+    except MappingError as e:
+        raise e
+
+    except Exception as e:
+        raise MappingError(f'Error at {path} trying to map {textwrap.shorten(str(v), width=60)} into type {t}', t, v) from e
+
+
+class WrapperType:
+    def __init__(self, next_type):
+        self.next_type = next_type
+
+    def __bind_field__(self, field):
+        self.field = field
+        if self.next_type is not Atom:
+            getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+
+    def __atoms__(self):
+        if hasattr(self, 'name_atom'):
+            return [self.name_atom]
+        elif self.next_type is Atom:
+            return []
+        else:
+            return getattr(self.next_type, '__atoms__', lambda: [])()
+
+class Named(WrapperType):
+    def __init__(self, next_type, name=None, omit_empty=True):
+        super().__init__(next_type)
+        self.name_atom = Atom(name) if name else None
+        self.omit_empty = omit_empty
+
+    def __bind_field__(self, field):
+        if self.next_type is not Atom:
+            getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+        if self.name_atom is None:
+            self.name_atom = Atom(field.name)
+
+    def __map__(self, obj, parent=None, path=''):
+        k, *obj = obj
+        if self.next_type in (int, float, str, Atom) or isinstance(self.next_type, AtomChoice):
+            return map_sexp(self.next_type, [*obj], parent=parent, path=f'{path}/{self.name_atom}')
+        else:
+            return map_sexp(self.next_type, obj, parent=parent, path=f'{path}/{self.name_atom}')
+
+    def __sexp__(self, value):
+        value = sexp(self.next_type, value)
+        if value is None:
+            return
+
+        if self.omit_empty and not value:
+            return
+
+        yield [self.name_atom, *value]
+
+    def __str__(self):
+        return f'Named={self.name_atom}({self.next_type})'
+
+
+class Rename(WrapperType):
+    def __init__(self, next_type, name=None):
+        super().__init__(next_type)
+        self.name_atom = Atom(name) if name else None
+
+    def __bind_field__(self, field):
+        if self.name_atom is None:
+            self.name_atom = Atom(field.name)
+        if hasattr(self.next_type, '__bind_field__'):
+            self.next_type.__bind_field__(field)
+
+    def __map__(self, obj, parent=None, path=''):
+        return map_sexp(self.next_type, obj, parent=parent, path=f'{path}/{self.name_atom}')
+
+    def __sexp__(self, value):
+        value, = sexp(self.next_type, value)
+        if self.next_type in (str, float, int, Atom): 
+            yield [self.name_atom, *value]
+        else:
+            key, *rest = value
+            yield [self.name_atom, *rest]
+
+    def __str__(self):
+        return f'Rename={self.name_atom}({self.next_type})'
+
+
+class OmitDefault(WrapperType):
+    def __bind_field__(self, field):
+        getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+        if field.default_factory != MISSING:
+            self.default = field.default_factory()
+        else:
+            self.default = field.default
+
+    def __map__(self, obj, parent=None, path=''):
+        return map_sexp(self.next_type, obj, parent=parent, path=path)
+
+    def __sexp__(self, value):
+        if value != self.default:
+            yield from sexp(self.next_type, value)
+
+    def __str__(self):
+        return f'OmitDefault({self.field})'
+
+
+class YesNoAtom:
+    def __init__(self, yes=Atom.yes, no=Atom.no):
+        self.yes, self.no = yes, no
+
+    def __map__(self, value, parent=None):
+        if not value: # compatibility with legacy flag style
+            return False
+        value, = value
+        return value == self.yes
+
+    def __sexp__(self, value):
+        yield self.yes if value else self.no
+
+
+class LegacyCompatibleFlag:
+    '''Variant of YesNoAtom that accepts both the `(flag <yes/no>)` variant and the bare `flag` variant for compatibility.'''
+
+    def __init__(self, yes=Atom.yes, no=Atom.no, value_when_empty=True):
+        self.yes, self.no = yes, no
+        self.value_when_empty = value_when_empty
+
+    def __map__(self, value, parent=None):
+        if value == []:
+            return self.value_when_empty
+
+        value, = value
+        return value == self.yes
+
+    def __sexp__(self, value):
+        yield self.yes if value else self.no
+
+
+class Wrap(WrapperType):
+    def __map__(self, value, parent=None, path=''):
+        value, = value
+        return map_sexp(self.next_type, value, parent=parent, path=path)
+
+    def __sexp__(self, value):
+        for inner in sexp(self.next_type, value):
+            yield [inner]
+
+    def __str__(self):
+        return f'Wrap({self.next_type})'
+
+
+class Array(WrapperType):
+    def __map__(self, value, parent=None, path=''):
+        return [map_sexp(self.next_type, [elem], parent=parent, path=path) for elem in value]
+    
+    def __sexp__(self, value):
+        for e in value:
+            yield from sexp(self.next_type, e)
+
+    def __str__(self):
+        return f'Array({self.next_type})'
+
+
+class Untagged(WrapperType):
+    def __map__(self, value, parent=None, path=''):
+        value, = value
+        return self.next_type.__map__([self.next_type.name_atom, *value], parent=parent, path=path)
+    
+    def __sexp__(self, value):
+        for inner in sexp(self.next_type, value):
+            _tag, *rest = inner
+            yield rest
+
+    def __str__(self):
+        return f'Untagged({self.next_type})'
+
+class List(WrapperType):
+    def __bind_field__(self, field):
+        self.attr = field.name
+
+    def __map__(self, value, parent, path=''):
+        l = getattr(parent, self.attr, [])
+        mapped = map_sexp(self.next_type, value, parent=parent, path=f'{path}/{self.attr}')
+        l.append(mapped)
+        setattr(parent, self.attr, l)
+
+    def __sexp__(self, value):
+        for elem in value:
+            yield from sexp(self.next_type, elem)
+
+    def __str__(self):
+        return f'List@{self.attr}({self.next_type})'
+
+
+class _SexpTemplate:
+    @staticmethod
+    def __atoms__(kls):
+        return [kls.name_atom]
+
+    @staticmethod
+    def __map__(kls, value, *args, parent=None, path='', **kwargs):
+        positional = iter(kls.positional)
+        inst = kls(*args, **kwargs)
+
+        for v in value[1:]: # skip key
+            if isinstance(v, Atom) and v in kls.keys:
+                name, etype = kls.keys[v]
+                mapped = map_sexp(etype, [v], parent=inst, path=f'{path}/{kls.name_atom}')
+                if mapped is not None:
+                    setattr(inst, name, mapped)
+
+            elif isinstance(v, list):
+                key = v[0]
+                if key in kls.keys:
+                    name, etype = kls.keys[key]
+                    mapped = map_sexp(etype, v, parent=inst, path=f'{path}/{kls.name_atom}')
+                    if mapped is not None:
+                        setattr(inst, name, mapped)
+
+                elif hasattr(inst, '__catchall__'):
+                    inst.__catchall__(v, path=f'{path}/{kls.name_atom}')
+
+                else:
+                    #print('class has keys:')
+                    #print('\n'.join(map(str, kls.keys)))
+                    raise TypeError(f'Unhandled keyed argument {v!r} while parsing {kls}')
+
+            else:
+                try:
+                    pos_key = next(positional)
+                    setattr(inst, pos_key.name, v)
+                except StopIteration:
+                    raise TypeError(f'Unhandled positional argument {v!r} while parsing {kls}')
+
+        getattr(inst, '__after_parse__', lambda x: None)(parent)
+        return inst
+
+    @staticmethod
+    def __sexp__(kls, value):
+        getattr(value, '__before_sexp__', lambda: None)()
+
+        out = [kls.name_atom]
+        for f in fields(kls):
+            if f.type is SEXP_END:
+                break
+            out += sexp(f.type, getattr(value, f.name))
+        yield out
+
+    @staticmethod
+    def parse(kls, data, *args, **kwargs):
+        return kls.__map__(parse_sexp(data), *args, **kwargs)
+
+    @staticmethod
+    def sexp(self):
+        return next(self.__sexp__(self))
+
+    @staticmethod
+    def __deepcopy__(self, memo):
+        return replace(self, **{f.name: copy.deepcopy(getattr(self, f.name), memo) for f in fields(self) if not f.kw_only})
+
+    @staticmethod
+    def __copy__(self):
+        # Even during a shallow copy, we need to deep copy any fields whose types have a __before_sexp__ method to avoid
+        # those from being called more than once on the same object.
+        return replace(self, **{f.name: copy.copy(getattr(self, f.name)) for f in fields(self) if not f.kw_only and hasattr(f.type, '__before_sexp__')})
+
+def sexp_type(name=None):
+    def register(cls):
+        cls = dataclass(cls)
+        cls.name_atom = Atom(name) if name is not None else None
+        for key in '__sexp__', '__map__', '__atoms__', 'parse':
+            if not hasattr(cls, key):
+                setattr(cls, key, classmethod(getattr(_SexpTemplate, key)))
+
+        for key in 'sexp', '__deepcopy__', '__copy__':
+            if not hasattr(cls, key):
+                setattr(cls, key, getattr(_SexpTemplate, key))
+
+        cls.positional = []
+        cls.keys = {}
+        for f in fields(cls):
+            f_type = f.type
+            if f_type is SEXP_END:
+                break
+
+            if hasattr(f_type, '__bind_field__'):
+                f_type.__bind_field__(f)
+
+            atoms = getattr(f_type, '__atoms__', lambda: [])
+            atoms = list(atoms())
+            for atom in atoms:
+                cls.keys[atom] = (f.name, f_type)
+            if not atoms:
+                cls.positional.append(f)
+
+        return cls
+    return register
+
+

src/gerbonara/cad/kicad/symbols.py

@@ -0,0 +1,631 @@
+"""
+Library for processing KiCad's symbol files.
+"""
+
+import json
+import string
+import math
+import re
+import sys
+import itertools
+from fnmatch import fnmatch
+from collections import defaultdict
+from dataclasses import field
+from pathlib import Path
+from typing import Any, Dict, List, Optional, Tuple
+
+from .sexp import *
+from .sexp_mapper import *
+from .base_types import *
+from ...utils import rotate_point, Tag, arc_bounds
+from ... import __version__
+from ...newstroke import Newstroke
+from .schematic_colors import *
+from .primitives import kicad_mid_to_center_arc, Margins
+
+
+PIN_ETYPE = AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive, Atom.free,
+                       Atom.unspecified, Atom.power_in, Atom.power_out, Atom.open_collector, Atom.open_emitter,
+                       Atom.no_connect, Atom.unconnected)
+
+
+PIN_STYLE = AtomChoice(Atom.line, Atom.inverted, Atom.clock, Atom.inverted_clock, Atom.input_low, Atom.clock_low,
+                       Atom.output_low, Atom.edge_clock_high, Atom.non_logic)
+
+
+@sexp_type('alternate')
+class AltFunction:
+    name: str = None
+    etype: PIN_ETYPE = Atom.unspecified
+    shape: PIN_STYLE = Atom.line
+
+
+@sexp_type('__styled_text')
+class StyledText:
+    value: str = None
+    effects: TextEffect = field(default_factory=TextEffect)
+
+
+@sexp_type('pin')
+class Pin:
+    etype: PIN_ETYPE = Atom.unspecified
+    style: PIN_STYLE = Atom.line
+    at: AtPos = field(default_factory=AtPos)
+    length: Named(float) = 2.54
+    hide: OmitDefault(Named(YesNoAtom())) = False
+    name: Rename(StyledText) = field(default_factory=StyledText)
+    number: Rename(StyledText) = field(default_factory=StyledText)
+    alternates: List(AltFunction) = field(default_factory=list)
+    _: SEXP_END = None
+    unit: object = None
+
+    def __after_parse__(self, parent=None):
+        self.unit = parent
+
+    @property
+    def direction(self):
+        return {0: 'R', 90: 'U', 180: 'L', 270: 'D'}.get(self.at.rotation, 'R')
+
+    @direction.setter
+    def direction(self, value):
+        self.at.rotation = {0: 'R', 90: 'U', 180: 'L', 270: 'D'}[value[0].upper()]
+
+    def bounding_box(self, default=None):
+        font = Newstroke.load()
+        strokes = list(font.render(self.name, size=2.54))
+        min_x = min(x for st in strokes for x, y in st)
+        min_y = min(y for st in strokes for x, y in st)
+        max_x = max(x for st in strokes for x, y in st)
+        max_y = max(y for st in strokes for x, y in st)
+        w, h = max_x - min_x, max_y - min_y
+        l = self.length + 0.2 + w
+
+        x1, y1 = x2, y2 = self.at.x, self.at.y
+        if self.at.rotation == 0:
+            x2 += w
+            y1 -= h/2
+            y2 += h/2
+        if self.at.rotation == 90:
+            y2 += w
+            x1 -= h/2
+            x2 += h/2
+        if self.at.rotation == 180:
+            x1 -= w
+            y1 -= h/2
+            y2 += h/2
+        if self.at.rotation == 270:
+            y1 -= w
+            x1 -= h/2
+            x2 += h/2
+        else:
+            raise ValueError(f'Invalid pin rotation {self.at.rotation}')
+
+        return (x1, y1), (x2, y2)
+
+    def to_svg(self, colorscheme, p_mirror, p_rotation):
+        if self.hide:
+            return
+
+        psx, psy = (-1 if p_mirror.x else 1), (-1 if p_mirror.y else 1)
+        x1, y1 = self.at.x, self.at.y
+        x2, y2 = self.at.x+self.length, self.at.y
+        if p_mirror.y:
+            p_xf = f'scale(-1 -1)'
+        elif p_mirror.x:
+            p_xf = f'scale(1 1)'
+        else:
+            p_xf = f'scale(1 -1)'
+        p_xf += f'rotate({p_rotation})'
+        xform = {'transform': f'{p_xf} translate({self.at.x:.3f} {self.at.y:.3f}) rotate({self.at.rotation})'}
+        style = {'stroke_width': 0.254, 'stroke': colorscheme.lines, 'stroke_linecap': 'round'}
+
+        yield Tag('path', **xform, **style, d=f'M 0 0 L {self.length:.3f} 0')
+
+        eps = 1
+        for tag in {
+                'line': [],
+                'inverted': [
+                    Tag('circle', **xform, **style, cx=x2-eps/3-0.2, cy=y2, r=eps/3)],
+                'clock': [
+                    Tag('path', **xform, **style, d=f'M {x2} {y2-eps/2} L {x2+eps/2} {y2} L {x2} {y2+eps/2}')],
+                'inverted_clock': [
+                    Tag('circle', **xform, **style, cx=x2-eps/3-0.2, cy=y2, r=eps/3),
+                    Tag('path', **xform, **style, d=f'M {x2} {y2-eps/2} L {x2+eps/2} {y2} L {x2} {y2+eps/2}')],
+                'input_low': [
+                    Tag('path', **xform, **style, d=f'M {x2} {y2} L {x2-eps} {y2-eps} L {x2-eps} {y2}')],
+                'clock_low': [
+                    Tag('path', **xform, **style, d=f'M {x2} {y2} L {x2-eps} {y2-eps} L {x2-eps} {y2}'),
+                    Tag('path', **xform, **style, d=f'M {x2} {y2-eps/2} L {x2+eps/2} {y2} L {x2} {y2+eps/2}')],
+                'output_low': [
+                    Tag('path', **xform, **style, d=f'M {x2} {y2-eps} L {x2-eps} {y2}')],
+                'edge_clock_high': [
+                    Tag('path', **xform, **style, d=f'M {x2} {y2} L {x2-eps} {y2-eps} L {x2-eps} {y2}'),
+                    Tag('path', **xform, **style, d=f'M {x2} {y2-eps/2} L {x2+eps/2} {y2} L {x2} {y2+eps/2}')],
+                'non_logic': [
+                    Tag('path', **xform, **style, d=f'M {x2-eps/2} {y2-eps/2} L {x2+eps/2} {y2+eps/2}'),
+                    Tag('path', **xform, **style, d=f'M {x2-eps/2} {y2+eps/2} L {x2+eps/2} {y2-eps/2}')],
+                # FIXME...
+        }.get(self.style, []):
+            yield tag
+
+        rot = self.at.rotation + p_rotation
+        trot = self.at.rotation
+        ax, ay = self.length+0.2, 0
+        ax, ay = rotate_point(ax, ay, math.radians(-self.at.rotation))
+
+        #lx, ly = self.at.x, -self.at.y
+        #lx, ly = rotate_point(lx, ly, math.radians(p_rotation))
+        #if p_mirror.y:
+        #    lx, ly = -lx, ly
+        #elif p_mirror.x:
+        #    lx, ly = lx, -ly
+        #yield Tag('circle', cx=lx, cy=ly, r='0.5', stroke='blue', stroke_width='0.1', fill='none', z_index='100')
+
+        lx, ly = self.at.x + ax, -self.at.y - ay
+        lx, ly = rotate_point(lx, ly, math.radians(p_rotation))
+        if p_mirror.y:
+            lx, ly = -lx, ly
+        elif p_mirror.x:
+            lx, ly = lx, -ly
+        #yield Tag('circle', cx=lx, cy=ly, r='0.5', stroke='red', stroke_width='0.1', fill='none', z_index='100')
+
+        h_align = 'left'
+        if p_mirror.y:
+            if trot in (0, 180):
+                trot = 180 - trot
+        elif p_mirror.x:
+            if p_rotation == 0:
+                if trot in (90, 270):
+                    trot = 360-trot
+            else:
+                if trot in (0, 180):
+                    trot = 180 - trot
+        frot = (trot + p_rotation)%360
+        sx, sy = 1, 1
+
+        if frot == 180:
+            frot = 0
+            h_align = 'right'
+        elif frot == 270:
+            frot = 90
+            h_align = 'right'
+
+        font = Newstroke.load()
+        if self.name.value != '~' and not self.unit.symbol.pin_names.hide:
+            yield font.render_svg(self.name.value,
+                                  size=self.name.effects.font.size.y or 1.27,
+                                  x0=0,
+                                  y0=0,
+                                  h_align=h_align,
+                                  v_align='middle',
+                                  rotation=-frot,
+                                  stroke=colorscheme.pin_names,
+                                  transform=f'translate({lx:.3f} {ly:.3f})',
+                                  scale=(sx, sy),
+                                  mirror=(False, False),
+                                  )
+
+        if self.number.value != '~' and not self.unit.symbol.pin_numbers.hide:
+            yield font.render_svg(self.number.value,
+                                  size=self.number.effects.font.size.y or 1.27,
+                                  x0=-0.4 if h_align == 'left' else 0.4,
+                                  y0=-0.4,
+                                  h_align={'left': 'right', 'right': 'left'}[h_align],
+                                  v_align='bottom',
+                                  rotation=-frot,
+                                  stroke=colorscheme.pin_numbers,
+                                  scale=(sx, sy),
+                                  transform=f'translate({lx:.3f} {ly:.3f})',
+                                  mirror=(False, False),
+                                  )
+
+
+
+@sexp_type('fill')
+class Fill:
+    type: Named(AtomChoice(Atom.none, Atom.outline, Atom.background)) = Atom.none
+
+    def svg(self, fg, bg):
+        if self.type == 'outline':
+            return fg
+        elif self.type == 'background':
+            return bg
+        else:
+            return 'none'
+
+
+@sexp_type('circle')
+class Circle:
+    center: Rename(XYCoord) = field(default_factory=XYCoord)
+    radius: Named(float) = 0.0
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: Fill = field(default_factory=Fill)
+
+    def bounding_box(self, default=None):
+        x, y, r = self.center.x, self.center.y, self.radius
+        return (x-r, y-r), (x+r, y+r)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield Tag('circle', cx=f'{self.center.x:.3f}', cy=f'{self.center.y:.3f}', r=f'{self.radius:.3f}',
+                  fill=self.fill.svg(colorscheme.lines, colorscheme.fill),
+                  **self.stroke.svg_attrs(colorscheme.lines))
+
+
+@sexp_type('radius')
+class ArcRadius:
+    at: AtPos = field(default_factory=AtPos)
+    length: Named(float) = 0.0
+    angles: Rename(XYCoord) = field(default_factory=XYCoord)
+
+
+@sexp_type('arc')
+class Arc:
+    start: Rename(XYCoord) = field(default_factory=XYCoord)
+    mid: Rename(XYCoord) = field(default_factory=XYCoord)
+    end: Rename(XYCoord) = field(default_factory=XYCoord)
+    radius: ArcRadius = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: Fill = field(default_factory=Fill)
+
+    def bounding_box(self, default=None):
+        (cx, cy), r = kicad_mid_to_center_arc(self.mid, self.start, self.end)
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.mid.x-x1, self.mid.y-x2
+        x3, y3 = (self.end.x - x1)/2, (self.end.y - y1)/2
+        clockwise = math.atan2(x2*y3-x3*y2, x2*x3+y2*y3) > 0
+        return arc_bounds(x1, y1, self.end.x, self.end.y, cx, cy, clockwise)
+
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        (cx, cy), r = kicad_mid_to_center_arc(self.mid, self.start, self.end)
+
+        x1r = self.start.x - cx
+        y1r = self.start.y - cy
+        x2r = self.end.x - cx
+        y2r = self.end.y - cy
+        a1 = math.atan2(x1r, y1r)
+        a2 = math.atan2(x2r, y2r)
+        da = (a2 - a1 + math.pi) % (2*math.pi) - math.pi
+
+        large_arc = int(da > math.pi)
+        d = f'M {self.start.x:.3f} {self.start.y:.3f} A {r:.3f} {r:.3f} 0 {large_arc} 0 {self.end.x:.3f} {self.end.y:.3f}'
+        yield Tag('path', d=d, fill=self.fill.svg(colorscheme.lines, colorscheme.fill),
+                  **self.stroke.svg_attrs(colorscheme.lines))
+
+
+@sexp_type('polyline')
+class Polyline:
+    pts: PointList = field(default_factory=PointList)
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: Fill = field(default_factory=Fill)
+
+    @property
+    def points(self):
+        return self.pts.xy
+
+    @points.setter
+    def points(self, value):
+        self.pts.xy = value
+
+    @property
+    def closed(self):
+        # if the last and first point are the same, we consider the polyline closed
+        # a closed triangle will have 4 points (A-B-C-A) stored in the list of points
+        return len(self.points) > 3 and self.points[0].isclose(self.points[-1])
+
+    def bounding_box(self, default=None):
+        if not self.points:
+            return default
+
+        return (min(p.x for p in self.points), min(p.y for p in self.points)), \
+               (max(p.x for p in self.points), max(p.y for p in self.points))
+
+    def as_rectangle(self):
+        (maxx, maxy, minx, miny) = self.bbox()
+        return Rectangle(minx, maxy, maxx, miny, self.stroke, self.fill)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        p0, *rest = self.points
+        if not rest:
+            return
+
+        d = ' '.join([f'M {p0.x:.3f} {p0.y:.3f}', *(f'L {pn.x:.3f} {pn.y:.3f}' for pn in rest)])
+        yield Tag('path', d=d, fill=self.fill.svg(colorscheme.lines, colorscheme.fill), **self.stroke.svg_attrs(colorscheme.lines))
+
+    def is_rectangle(self):
+        # A rectangle has 5 points and is closed
+        if len(self.points) != 5 or not self.is_closed():
+            return False
+            
+        # Check that we have all four corners present
+        (x1, y1), (x2, y2) = self.bbox()
+        if not all(any(cand.isclose(pt) for cand in self.points[:-1]) for pt in
+                   [(x1, y1), (x1, y2), (x2, y2), (x2, y1)]):
+            return False
+
+        # Check that we only have horizontal or vertical lines
+        if any(x2-x1 and y2-y1 for (x1, y1), (x2,  y2) in zip(self.points[:-1], self.points[1:])):
+            return False
+
+        return True
+
+
+@sexp_type('at')
+class TextPos(XYCoord):
+    x: float = 0 # in millimeter
+    y: float = 0 # in millimeter
+    rotation: int = 0  # in degrees
+
+    def __after_parse__(self, parent):
+        self.rotation = self.rotation / 10
+
+    def __before_sexp__(self):
+        self.rotation = round((self.rotation % 360) * 10)
+
+    @property
+    def rotation_rad(self):
+        return math.radians(self.rotation)
+
+    @rotation_rad.setter
+    def rotation_rad(self, value):
+        self.rotation = math.degrees(value)
+
+
+@sexp_type('text')
+class Text(TextMixin):
+    text: str = None
+    at: TextPos = field(default_factory=TextPos)
+    rotation: float = None
+    effects: TextEffect = field(default_factory=TextEffect)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield from TextMixin.to_svg(self, colorscheme.text)
+
+
+@sexp_type('rectangle')
+class Rectangle:
+    # Some v6 symbols use rectangles, newer ones encode them as polylines.
+    # At some point in time we can most likely remove this class since its not used anymore
+
+    start: Rename(XYCoord) = None
+    end: Rename(XYCoord) = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: Fill = field(default_factory=Fill)
+
+    def to_polyline(self):
+        x1, y1 = self.start.x, self.start.y
+        x2, y2 = self.end.x, self.end.y
+        return Polyline(PointList([XYCoord(x1, y1), XYCoord(x2, y1), XYCoord(x2, y2), XYCoord(x1, y2), XYCoord(x1, y1)]),
+                        self.stroke, self.fill)
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        return self.to_polyline().to_svg(colorscheme)
+
+
+@sexp_type('property')
+class Property(TextMixin):
+    private: Flag() = False
+    name: str = None
+    value: str = None
+    id: Named(int) = None
+    at: AtPos = field(default_factory=AtPos)
+    show_name: Flag() = False
+    effects: TextEffect = field(default_factory=TextEffect)
+
+    # Alias value for text mixin
+    @property
+    def text(self):
+        return self.value
+
+    @text.setter
+    def text(self, value):
+        self.value = value
+
+    def to_svg(self, colorscheme=Colorscheme.KiCad):
+        yield from TextMixin.to_svg(self, colorscheme.text)
+
+
+@sexp_type('pin_numbers')
+class PinNumberSpec:
+    hide: Named(YesNoAtom()) = False
+
+
+@sexp_type('pin_names')
+class PinNameSpec:
+    offset: OmitDefault(Named(float)) = 0.508
+    hide: OmitDefault(Named(YesNoAtom())) = False
+
+@sexp_type('text_box')
+class TextBox:
+    text: str = ''
+    exclude_from_sim: OmitDefault(Named(YesNoAtom())) = False
+    at: AtPos = field(default_factory=AtPos)
+    size: Rename(XYCoord) = field(default_factory=XYCoord)
+    margins: Margins = None
+    stroke: Stroke = field(default_factory=Stroke)
+    fill: Fill = field(default_factory=Fill)
+    effects: TextEffect = field(default_factory=TextEffect)
+
+
+@sexp_type('symbol')
+class Unit:
+    name: str = None
+    circles: List(Circle) = field(default_factory=list)
+    arcs: List(Arc) = field(default_factory=list)
+    polylines: List(Polyline) = field(default_factory=list)
+    rectangles: List(Rectangle) = field(default_factory=list)
+    texts: List(Text) = field(default_factory=list)
+    text_boxes: List(TextBox) = field(default_factory=list)
+    pins: List(Pin) = field(default_factory=list)
+    unit_name: Named(str) = None
+    _ : SEXP_END = None
+    unit_global: Flag() = False
+    style_global: Flag() = False
+    demorgan_style: int = 1
+    unit_index: int = 1
+    symbol = None
+
+    def __after_parse__(self, parent):
+        self.symbol = parent
+
+        if not (m := re.fullmatch(r'(.*)_([0-9]+)_([0-9]+)', self.name)):
+            raise FormatError(f'Invalid unit name "{self.name}"')
+        sym_name, unit_index, demorgan_style = m.groups()
+        if sym_name != self.symbol.raw_name.rpartition(':')[2]:
+            raise FormatError(f'Unit name "{self.name}" does not match symbol name "{self.symbol.name}"')
+        self.demorgan_style = int(demorgan_style)
+        self.unit_index = int(unit_index)
+        self.style_global = self.demorgan_style == 0
+        self.unit_global = self.unit_index == 0
+
+    @property
+    def graphical_elements(self):
+        yield from self.rectangles
+        yield from self.polylines
+        yield from self.circles
+        yield from self.arcs
+        yield from self.texts
+
+    def __before_sexp__(self):
+        self.name = f'{self.symbol.name}_{self.unit_index}_{self.demorgan_style}'
+
+    def pin_stacks(self):
+        stacks = defaultdict(lambda: set())
+        for pin in self.all_pins():
+            stacks[(pin.at.x, pin.at.y)].add(pin)
+        return stacks
+
+
+@sexp_type('symbol')
+class Symbol:
+    raw_name: str = None
+    extends: Named(str) = None
+    power: Wrap(Flag()) = False
+    pin_numbers: OmitDefault(PinNumberSpec) = field(default_factory=PinNumberSpec)
+    pin_names: OmitDefault(PinNameSpec) = field(default_factory=PinNameSpec)
+    exclude_from_sim: OmitDefault(Named(YesNoAtom())) = False
+    exclude_from_sim: Named(YesNoAtom()) = False
+    in_bom: Named(YesNoAtom()) = True
+    on_board: Named(YesNoAtom()) = True
+    properties: List(Property) = field(default_factory=list)
+    units: List(Unit) = field(default_factory=list)
+    embedded_fonts: Named(YesNoAtom()) = False
+    _ : SEXP_END = None
+    library = None
+    name: str = None
+    library_name: str = None
+
+    def __after_parse__(self, parent):
+        self.library = parent
+
+        self.library_name, _, self.name = self.raw_name.rpartition(':')
+
+        if self.extends:
+            self.in_bom = None
+            self.on_board = None
+
+        self.properties = {prop.name: prop for prop in self.properties}
+        if (prop := self.properties.get('ki_fp_filters')):
+            prop.value = prop.value.split() if prop.value else []
+
+    def __before_sexp__(self):
+        if (prop := self.properties.get('ki_fp_filters')):
+            if not isinstance(prop.value, str):
+                prop.value = ' '.join(prop.value)
+        self.properties = list(self.properties.values())
+
+    def default_properties(self):
+        for i, (name, value, hide) in enumerate([
+            ('Reference',       'U',        False),
+            ('Value',           None,       False),
+            ('Footprint',       None,       True),
+            ('Datasheet',       None,       True),
+            ('ki_locked',       None,       True),
+            ('ki_keywords',     None,       True),
+            ('ki_description',  None,       True),
+            ('ki_fp_filters',   None,       False),
+            ]):
+            self.properties[name] = Property(name=name, value=value, id=i, effects=TextEffect(hide=hide))
+
+    def resolve(self):
+        if self.extends:
+            return self.library[self.extends]
+        else:
+            return self
+
+    def is_graphic_symbol(self):
+        return self.extends is None and (
+            not self.pins or self.get_property("Reference").value == "#SYM"
+        )
+
+    def pins_by_name(self, demorgan_style=None):
+        pins = defaultdict(lambda: set())
+        for unit in self.units(demorgan_style):
+            for pin in unit.all_pins:
+                pins[pin.name].add(pin)
+        return pins
+
+    def pins_by_number(self, demorgan_style=None):
+        pins = defaultdict(lambda: set())
+        for unit in self.units(demorgan_style):
+            for pin in unit.all_pins:
+                pins[pin.number].add(pin)
+        return pins
+
+    def filter_pins(self, name=None, direction=None, electrical_type=None):
+        for pin in self.all_pins:
+            if name and not fnmatch(pin.name, name):
+                continue
+            if direction and not pin.direction in direction:
+                continue
+            if electrical_type and not pin.etype in electical_type:
+                continue
+            yield pin
+
+    def heuristically_small(self):
+        """ Heuristically try to determine whether this is a "small" component like a resistor, capacitor, LED, diode,
+        or transistor etc. When we have at most two pins, or there is no filled rectangle as symbol outline and we have
+        3 or 4 pins, we assume this is a small symbol.
+        """
+        if len(self.all_pins) <= 2:
+            return True
+        if len(self.all_pins) > 4:
+            return False
+        return bool(self.get_center_rectangle(range(self.unit_count)))
+
+
+SUPPORTED_FILE_FORMAT_VERSIONS = [20211014, 20220914]
+@sexp_type('kicad_symbol_lib')
+class Library:
+    _version: Named(int, name='version') = 20211014
+    generator: Named(str) = Atom.gerbonara
+    generator_version: Named(str) = __version__
+    symbols: List(Symbol) = field(default_factory=list)
+    _ : SEXP_END = None
+    original_filename: str = None
+
+    @property
+    def version(self):
+        return self._version
+
+    @version.setter
+    def version(self, value):
+        if value not in SUPPORTED_FILE_FORMAT_VERSIONS:
+            raise FormatError(f'File format version {value} is not supported. Supported versions are {", ".join(map(str, SUPPORTED_FILE_FORMAT_VERSIONS))}.')
+
+    @classmethod
+    def open(cls, filename: str):
+        with open(filename) as f:
+            return cls.parse(f.read())
+
+    def write(self, filename=None):
+        with open(filename or self.original_filename, 'w') as f:
+            f.write(build_sexp(sexp(self)))
+
+
+if __name__ == "__main__":
+    if len(sys.argv) >= 2:
+        a = Library.open(sys.argv[1])
+        print(build_sexp(sexp(a)))
+    else:
+        print("pass a .kicad_sym file please")

src/gerbonara/cad/kicad/tmtheme.py

@@ -0,0 +1,88 @@
+
+from xml.etree import ElementTree
+import base64
+import json
+from pathlib import Path
+
+def _map_primitive(element):
+    match element.tag:
+        case 'data':
+            return base64.b64decode(element.text)
+        case 'date':
+            return element.text
+        case 'true':
+            return True
+        case 'false':
+            return False
+        case 'real':
+            return float(element.text)
+        case 'integer':
+            return int(element.text)
+        case 'string':
+            return element.text
+        case 'array':
+            return [_map_primitive(child) for child in element]
+        case 'dict':
+            children = list(element)
+            return {k.text: _map_primitive(v) for k, v in zip(children[0::2], children[1::2])}
+
+
+def parse_shitty_json(data):
+    # Parse apple plist XML
+    root = ElementTree.fromstring(data)
+    return _map_primitive(root[0])
+
+
+class _SublimeColorschemeSuper:
+    def __init__(self, s, by_scope):
+        def lookup(default, *scopes):
+            for scope in scopes:
+                if not (elem := by_scope.get(scope)):
+                    continue
+
+                if 'foreground' not in elem:
+                    continue
+
+                return elem['foreground']
+            return default
+
+        self.background = s.get('background', 'white')
+        fg = s.get('foreground', 'black')
+        self.bus = lookup(fg, 'constant.other', 'storage.type')
+        self.wire = self.lines = lookup(fg, 'constant.other')
+        self.no_connect = lookup(fg, 'constant.language', 'variable')
+        self.text = lookup(fg, 'constant.numeric', 'constant.numeric.hex', 'storage.type.number')
+        self.pin_names = lookup(fg, 'constant.character', 'constant.other')
+        self.pin_numbers = fg
+        self.values = lookup(fg, 'constant.character.format.placeholder', 'constant.other.placeholder', 'entity.name.tag', 'support.type', 'support.class', 'entity.other.inherited-class')
+        self.labels = lookup(fg, 'constant.numeric', 'constant.numeric.hex', 'storage.type.number')
+        self.fill = s.get('background')
+
+
+class TmThemeSchematic(_SublimeColorschemeSuper):
+    def __init__(self, data):
+        self.theme = parse_shitty_json(data)
+        s = self.theme['settings'][0]['settings']
+        by_scope = {}
+        for elem in self.theme['settings']:
+            if 'scope' not in elem:
+                continue
+            for scope in elem['scope'].split(','):
+                by_scope[scope.strip()] = elem.get('settings', {})
+        super().__init__(s, by_scope)
+
+
+class SublimeSchematic(_SublimeColorschemeSuper):
+    def __init__(self, data):
+        self.theme = json.loads(data)
+        s = self.theme['globals']
+        by_scope = {}
+        for elem in self.theme['rules']:
+            for scope in elem['scope'].split(','):
+                by_scope[scope.strip()] = elem
+        super().__init__(s, by_scope)
+
+
+if __name__ == '__main__':
+    print(parse_shitty_json(Path('/tmp/witchhazelhypercolor.tmTheme').read_text()))
+

src/gerbonara/cad/primitives.py

@@ -0,0 +1,840 @@
+
+import sys
+import math
+import warnings
+from copy import copy
+from itertools import zip_longest, chain
+from dataclasses import dataclass, field, replace, KW_ONLY
+from collections import defaultdict
+
+from ..utils import LengthUnit, MM, rotate_point, svg_arc, sum_bounds, bbox_intersect, Tag, offset_bounds
+from ..layers import LayerStack
+from ..graphic_objects import Line, Arc, Flash
+from ..apertures import Aperture, CircleAperture, ObroundAperture, RectangleAperture, ExcellonTool
+from ..newstroke import Newstroke
+
+
+class UNDEFINED:
+    pass
+
+def sgn(x):
+    return -1 if x < 0 else 1
+
+
+class KeepoutError(ValueError):
+    def __init__(self, obj, keepout, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.obj = obj
+        self.keepout = keepout
+
+
+newstroke_font = None
+
+
+class Board:
+    def __init__(self, w=None, h=None, corner_radius=1.5, center=False, default_via_hole=0.4, default_via_diameter=0.8, x=0, y=0, rotation=0, unit=MM):
+        self.x, self.y = x, y
+        self.rotation = 0
+        self.objects = []
+        self.outline = []
+        self.extra_silk_top = []
+        self.extra_silk_bottom = []
+        self.keepouts = []
+        self.default_via_hole = MM(default_via_hole, unit)
+        self.default_via_diameter = MM(default_via_diameter, unit)
+        self.unit = unit
+        if w or h:
+            if w and h:
+                self.rounded_rect_outline(w, h, r=corner_radius, center=center)
+                self.w, self.h = w, h
+            else:
+                raise ValueError('Either both, w and h, or neither of them must be given.')
+        else:
+            self.w = self.h = None
+
+    @property
+    def abs_pos(self):
+        return self.x, self.y, self.rotation, False
+
+    def add_silk(self, side, obj):
+        if side not in ('top', 'bottom'):
+            raise ValueError('side must be one of "top" or "bottom".')
+
+        if side == 'top':
+            self.extra_silk_top.append(obj)
+        else:
+            self.extra_silk_bottom.append(obj)
+
+    def add_text(self, *args, **kwargs):
+        self.objects.append(Text(*args, **kwargs))
+
+    def add_keepout(self, bbox, unit=MM):
+        ((_x_min, _y_min), (_x_max, _y_max)) = bbox
+        self.keepouts.append(MM.convert_bounds_from(unit, bbox))
+
+    def add(self, obj, keepout_errors='raise'):
+        if keepout_errors not in ('ignore', 'raise', 'warn', 'skip'):
+            raise ValueError('keepout_errors must be one of "ignore", "raise", "warn" or "skip".')
+
+        if keepout_errors != 'ignore':
+            for ko in self.keepouts:
+                if obj.overlaps(ko, unit=MM):
+                    if keepout_errors == 'warn':
+                        warnings.warn(f'Object with bounds {obj.bounding_box(MM)} [mm] hits one or more keepout areas')
+                    elif keepout_errors == 'raise':
+                        raise KeepoutError(obj, ko, msg)
+                    return
+
+        obj.parent = self
+        self.objects.append(obj)
+
+    def via(self, x, y, diameter=None, hole=None, keepout_errors='raise', unit=MM):
+        diameter = diameter or unit(self.default_via_dia, MM)
+        hole = hole or unit(self.default_via_hole, MM)
+        obj = Via(x, y, diameter, hole, unit=unit, keepout_errors=keepout_errors)
+        self.add(obj)
+        return obj
+
+    def rounded_rect_outline(self, w, h, r=0, x0=None, y0=None, center=False, unit=MM):
+        if x0 is None:
+            x0 = -w/2 if center else 0
+        if y0 is None:
+            y0 = -h/2 if center else 0
+
+        ap = CircleAperture(0.05, unit=MM)
+
+        self.outline.append(Line(x0+r, y0, x0+w-r, y0, ap, unit=unit))
+        if r:
+            self.outline.append(Arc(x0+w-r, y0, x0+w, y0+r, 0, r, False, ap, unit=unit))
+        self.outline.append(Line(x0+w, y0+r, x0+w, y0+h-r, ap, unit=unit))
+        if r:
+            self.outline.append(Arc(x0+w, y0+h-r, x0+w-r, y0+h, -r, 0, False, ap, unit=unit))
+        self.outline.append(Line(x0+w-r, y0+h, x0+r, y0+h, ap, unit=unit))
+        if r:
+            self.outline.append(Arc(x0+r, y0+h, x0, y0+h-r, 0, -r, False, ap, unit=unit))
+        self.outline.append(Line(x0, y0+h-r, x0, y0+r, ap, unit=unit))
+        if r:
+            self.outline.append(Arc(x0, y0+r, x0+r, y0, r, 0, False, ap, unit=unit))
+
+    def layer_stack(self, layer_stack=None):
+        if layer_stack is None:
+            layer_stack = LayerStack(board_name='proto')
+
+        cache = {}
+        for obj in chain(self.objects):
+            obj.render(layer_stack, cache)
+
+        layer_stack['mechanical', 'outline'].objects.extend(self.outline)
+        layer_stack['top', 'silk'].objects.extend(self.extra_silk_top)
+        layer_stack['bottom', 'silk'].objects.extend(self.extra_silk_bottom)
+
+        return layer_stack
+
+    def svg(self, margin=0, arg_unit=MM, svg_unit=MM, force_bounds=None):
+        return self.layer_stack().to_svg(margin=margin, arg_unit=arg_unit, svg_unit=svg_unit,
+                                                 force_bounds=force_bounds)
+
+    def pretty_svg(self, side='top', margin=0, arg_unit=MM, svg_unit=MM, force_bounds=None, inkscape=False, colors=None):
+        return self.layer_stack().to_pretty_svg(side=side, margin=margin, arg_unit=arg_unit, svg_unit=svg_unit,
+                                                   force_bounds=force_bounds, inkscape=inkscape, colors=colors)
+
+
+@dataclass
+class Positioned:
+    x: float
+    y: float
+    _: KW_ONLY
+    rotation: float = 0.0
+    flip: bool = False
+    unit: LengthUnit = MM
+    parent: object = None
+
+    @property
+    def abs_pos(self):
+        if self.parent is None:
+            px, py, pa, pf = 0, 0, 0, False
+        else:
+            px, py, pa, pf = self.parent.abs_pos
+
+        return self.x+px, self.y+py, self.rotation+pa, (bool(self.flip) != bool(pf))
+
+    def bounding_box(self, unit=MM):
+        stack = LayerStack()
+        self.render(stack)
+        objects = chain(*(l.objects for l in stack.graphic_layers.values()),
+                        stack.drill_pth.objects, stack.drill_npth.objects)
+        objects = list(objects)
+        #print('foo', type(self).__name__,
+        #      [(type(obj).__name__, [prim.bounding_box() for prim in obj.to_primitives(unit)]) for obj in objects], file=sys.stderr)
+        return sum_bounds(prim.bounding_box() for obj in objects for prim in obj.to_primitives(unit))
+
+    def overlaps(self, bbox, unit=MM):
+        return bbox_intersect(self.bounding_box(unit), bbox)
+
+    @property
+    def single_sided(self):
+        return True
+
+
+# The dataclass API is slightly idiotic here, so we have to duplicate the entire thing.
+@dataclass(frozen=True)
+class FrozenPositioned:
+    x: float
+    y: float
+    _: KW_ONLY
+    rotation: float = 0.0
+    flip: bool = False
+    unit: LengthUnit = MM
+    parent: object = None
+
+    @property
+    def abs_pos(self):
+        if self.parent is None:
+            px, py, pa, pf = 0, 0, 0, False
+        else:
+            px, py, pa, pf = self.parent.abs_pos
+
+        return self.x+px, self.y+py, self.rotation+pa, (bool(self.flip) != bool(pf))
+
+    def bounding_box(self, unit=MM):
+        stack = LayerStack()
+        self.render(stack)
+        objects = chain(*(l.objects for l in stack.graphic_layers.values()),
+                        stack.drill_pth.objects, stack.drill_npth.objects)
+        objects = list(objects)
+        #print('foo', type(self).__name__,
+        #      [(type(obj).__name__, [prim.bounding_box() for prim in obj.to_primitives(unit)]) for obj in objects], file=sys.stderr)
+        return sum_bounds(prim.bounding_box() for obj in objects for prim in obj.to_primitives(unit))
+
+    def overlaps(self, bbox, unit=MM):
+        return bbox_intersect(self.bounding_box(unit), bbox)
+
+    @property
+    def single_sided(self):
+        return True
+
+
+@dataclass
+class Graphics(Positioned):
+    top_copper: list = field(default_factory=list)
+    top_mask: list = field(default_factory=list)
+    top_silk: list = field(default_factory=list)
+    top_paste: list = field(default_factory=list)
+    bottom_copper: list = field(default_factory=list)
+    bottom_mask: list = field(default_factory=list)
+    bottom_silk: list = field(default_factory=list)
+    bottom_paste: list = field(default_factory=list)
+    drill_npth: list = field(default_factory=list)
+    drill_pth: list = field(default_factory=list)
+
+    def render(self, layer_stack, cache=None):
+        x, y, rotation, flip = self.abs_pos
+        top, bottom = ('bottom', 'top') if flip else ('top', 'bottom')
+
+        for target, source in [
+                (layer_stack[top, 'copper'],    self.top_copper),
+                (layer_stack[top, 'mask'],      self.top_mask),
+                (layer_stack[top, 'silk'],      self.top_silk),
+                (layer_stack[top, 'paste'],     self.top_paste),
+                (layer_stack[bottom, 'copper'], self.bottom_copper),
+                (layer_stack[bottom, 'mask'],   self.bottom_mask),
+                (layer_stack[bottom, 'silk'],   self.bottom_silk),
+                (layer_stack[bottom, 'paste'],  self.bottom_paste),
+                (layer_stack.drill_pth,         self.drill_pth),
+                (layer_stack.drill_npth,        self.drill_npth)]:
+
+            for fe in source:
+                fe = copy(fe)
+                fe.rotate(rotation)
+                fe.offset(x, y, self.unit)
+                target.objects.append(fe)
+
+    def bounding_box(self, unit=MM):
+        if math.isclose(self.rotation, 0, abs_tol=1e-3):
+            return offset_bounds(sum_bounds((obj.bounding_box(unit=unit) for obj in chain(
+                    self.top_copper,
+                    self.top_mask,
+                    self.top_silk,
+                    self.top_paste,
+                    self.bottom_copper,
+                    self.bottom_mask,
+                    self.bottom_silk,
+                    self.bottom_paste,
+                    self.drill_npth,
+                    self.drill_pth,
+                ))), unit(self.x, self.unit), unit(self.y, self.unit))
+        else:
+            return super().bounding_box(unit)
+
+    @property
+    def single_sided(self):
+        any_top = self.top_copper or self.top_mask or self.top_paste or self.top_silk
+        any_bottom = self.bottom_copper or self.bottom_mask or self.bottom_paste or self.bottom_silk
+        any_drill = self.drill_npth or self.drill_pth
+        return not (any_drill or (any_top and any_bottom))
+
+
+@dataclass
+class ObjectGroup(Positioned):
+    objects: list = field(default_factory=list)
+
+    def render(self, layer_stack, cache=None):
+        for obj in self.objects:
+            if not isinstance(obj, Positioned):
+                raise ValueError(f'ObjectGroup members must be children of Positioned, not {type(obj)}')
+
+            obj.parent = self
+            obj.render(layer_stack, cache=cache)
+
+    def bounding_box(self, unit=MM):
+        if math.isclose(self.rotation, 0, abs_tol=1e-3):
+            return offset_bounds(sum_bounds((obj.bounding_box(unit=unit) for obj in self.objects)),
+                                 unit(self.x, self.unit), unit(self.y, self.unit))
+        else:
+            return super().bounding_box(unit)
+
+    @property
+    def single_sided(self):
+        return all(obj.single_sided for obj in self.objects)
+
+
+@dataclass
+class Text(Positioned):
+    text: str
+    font_size: float = 2.5
+    stroke_width: float = 0.25
+    h_align: str = 'left'
+    v_align: str = 'bottom'
+    layer: str = 'silk'
+    polarity_dark: bool = True
+
+    def render(self, layer_stack, cache=None):
+        obj_x, obj_y, rotation, flip = self.abs_pos
+        global newstroke_font
+
+        if newstroke_font is None:
+            newstroke_font = Newstroke()
+
+        strokes = list(newstroke_font.render(self.text, size=self.font_size))
+        if not strokes:
+            return
+
+        xs = [x for points in strokes for x, _y in points]
+        ys = [y for points in strokes for _x, y in points]
+        min_x, min_y, max_x, max_y = min(xs), min(ys), max(xs), max(ys)
+        h = self.font_size + self.stroke_width # (max_y - min_y)
+
+        if self.h_align == 'left':
+            x0 = 0
+        elif self.h_align == 'center':
+            x0 = -max_x/2
+        elif self.h_align == 'right':
+            x0 = -max_x
+        else:
+            raise ValueError('h_align must be one of "left", "center", or "right".')
+
+        if self.v_align == 'bottom':
+            y0 = h
+        elif self.v_align == 'middle':
+            y0 = h/2
+        elif self.v_align == 'top':
+            y0 = 0
+        else:
+            raise ValueError('v_align must be one of "top", "middle", or "bottom".')
+
+        if self.flip:
+            x0 += min_x + max_x
+            x_sign = -1
+        else:
+            x_sign = 1
+
+        ap = CircleAperture(self.stroke_width, unit=self.unit)
+
+        for stroke in strokes:
+            for (x1, y1), (x2, y2) in zip(stroke[:-1], stroke[1:]):
+                obj = Line(x0+x_sign*x1, y0+y1, x0+x_sign*x2, y0+y2, aperture=ap, unit=self.unit, polarity_dark=self.polarity_dark)
+                obj.rotate(rotation)
+                obj.offset(obj_x, obj_y)
+                layer_stack['bottom' if flip else 'top', self.layer].objects.append(obj)
+
+    def bounding_box(self, unit=MM):
+        approx_w = len(self.text)*self.font_size*0.75 + self.stroke_width
+        approx_h = self.font_size + self.stroke_width
+
+        if self.h_align == 'left':
+            x0 = 0
+        elif self.h_align == 'center':
+            x0 = -approx_w/2
+        elif self.h_align == 'right':
+            x0 = -approx_w
+
+        if self.v_align == 'top':
+            y0 = 0
+        elif self.v_align == 'middle':
+            y0 = -approx_h/2
+        elif self.v_align == 'bottom':
+            y0 = -approx_h
+
+        return (self.x+x0, self.y+y0), (self.x+x0+approx_w, self.y+y0+approx_h)
+
+
+@dataclass(frozen=True, slots=True)
+class PadStackAperture:
+    aperture: Aperture
+    side: str
+    layer: str
+    offset_x: float = 0 # in PadStack units
+    offset_y: float = 0
+    rotation: float = 0
+    invert: bool = False
+
+
+@dataclass(frozen=True, slots=True)
+class PadStack:
+    _: KW_ONLY
+    unit: LengthUnit = MM
+
+    @property
+    def apertures(self):
+        raise NotImplementedError()
+
+    def flashes(self, x, y, rotation: float = 0, flip: bool = False):
+        for ap in self.apertures:
+            aperture = ap.aperture.rotated(ap.rotation + rotation)
+            fl = Flash(ap.offset_x, ap.offset_y, aperture, polarity_dark=not ap.invert, unit=self.unit)
+            fl.rotate(rotation)
+            fl.offset(x, y)
+            side = ap.side
+            if flip:
+                side = {'top': 'bottom', 'bottom': 'top'}.get(side, side)
+            yield side, ap.layer, fl
+
+    def render(self, layer_stack, x, y, rotation: float = 0, flip: bool = False):
+        for side, layer, flash in self.flashes(x, y, rotation, flip):
+            if side == 'drill' and layer == 'plated':
+                layer_stack.drill_pth.objects.append(flash)
+
+            elif side == 'drill' and layer == 'nonplated':
+                layer_stack.drill_npth.objects.append(flash)
+
+            elif (side, layer) in layer_stack:
+                layer_stack[side, layer].objects.append(flash)
+
+    @property
+    def single_sided(self):
+        return len({ap.side for ap in self.apertures}) <= 1
+
+
+@dataclass(frozen=True, slots=True)
+class SMDStack(PadStack):
+    aperture: Aperture
+    mask_expansion: float = 0.0
+    paste_expansion: float = 0.0
+    paste: bool = True
+    flip: bool = False
+
+    @property
+    def side(self):
+        return 'bottom' if self.flip else 'top'
+
+    @property
+    def apertures(self):
+        yield PadStackAperture(self.aperture, self.side, 'copper')
+        yield PadStackAperture(self.aperture.dilated(self.mask_expansion, self.unit), self.side, 'mask')
+        if self.paste:
+            yield PadStackAperture(self.aperture.dilated(self.paste_expansion, self.unit), self.side, 'paste')
+
+    @classmethod
+    def rect(kls, w, h, rotation=0, mask_expansion=0.0, paste_expansion=0.0, paste=True, flip=False, unit=MM):
+        ap = RectangleAperture(w, h, unit=unit).rotated(rotation)
+        return kls(ap, mask_expansion, paste_expansion, paste, flip, unit=unit)
+
+    @classmethod
+    def circle(kls, dia, mask_expansion=0.0, paste_expansion=0.0, paste=True, flip=False, unit=MM):
+        return kls(CircleAperture(dia, unit=unit), mask_expansion, paste_expansion, paste, flip, unit=unit)
+    
+
+@dataclass(frozen=True, slots=True)
+class MechanicalHoleStack(PadStack):
+    drill_dia: float
+    mask_expansion: float = 0.0
+    mask_aperture = None
+
+    @property
+    def apertures(self):
+        mask_aperture = self.mask_aperture or CircleAperture(self.drill_dia + self.mask_expansion, unit=self.unit)
+        yield PadStackAperture(mask_aperture, 'top', 'mask')
+        yield PadStackAperture(mask_aperture, 'bottom', 'mask')
+
+    @property
+    def single_sided(self):
+        return False
+
+
+@dataclass(frozen=True, slots=True)
+class THTPad(PadStack):
+    drill_dia: float
+    pad_top: SMDStack
+    pad_bottom: SMDStack = None
+    aperture_inner: Aperture = UNDEFINED
+    plated: bool = True
+
+    def __post_init__(self):
+        if self.pad_bottom is None:
+            object.__setattr__(self, 'pad_bottom', replace(self.pad_top, flip=True))
+        
+        if self.aperture_inner is UNDEFINED:
+            object.__setattr__(self, 'aperture_inner', self.pad_top.aperture)
+
+        if self.pad_top.flip:
+            raise ValueError('top pad cannot be flipped')
+
+    @property
+    def plating(self):
+        return 'plated' if self.plated else 'nonplated'
+
+    @property
+    def apertures(self):
+        yield from self.pad_top.apertures
+        yield from self.pad_bottom.apertures
+        if self.aperture_inner is not None:
+            yield PadStackAperture(self.aperture_inner, 'inner', 'copper')
+        yield PadStackAperture(ExcellonTool(self.drill_dia, plated=self.plated, unit=self.unit), 'drill', self.plating)
+
+    @property
+    def single_sided(self):
+        return False
+
+    @classmethod
+    def rect(kls, drill_dia, w, h, rotation=0, mask_expansion=0.0, paste_expansion=0.0, paste=True, plated=True, unit=MM):
+        pad = SMDStack.rect(w, h, rotation, mask_expansion, paste_expansion, paste, unit=unit)
+        return kls(drill_dia, pad, plated=plated)
+
+    @classmethod
+    def circle(kls, drill_dia, dia, rotation=0, mask_expansion=0.0, paste_expansion=0.0, paste=True, plated=True, unit=MM):
+        pad = SMDStack.circle(dia, mask_expansion, paste_expansion, paste, unit=unit)
+        return kls(drill_dia, pad, plated=plated)
+
+    @classmethod
+    def obround(kls, drill_dia, w, h, rotation=0, mask_expansion=0.0, paste_expansion=0.0, paste=True, plated=True, unit=MM):
+        ap = ObroundAperture(w, h, unit=unit).rotated(rotation)
+        pad = SMDStack(ap, mask_expansion, paste_expansion, paste, unit=unit)
+        return kls(drill_dia, pad, plated=plated)
+
+@dataclass(frozen=True, slots=True)
+class ThroughViaStack(PadStack):
+    hole: float
+    dia: float = None
+    tented: bool = True
+
+    def __post_init__(self):
+        if self.dia == None:
+            object.__setattr__(self, 'dia', self.hole*2)
+
+    @property
+    def single_sided(self):
+        return False
+
+    @property
+    def apertures(self):
+        copper_aperture = CircleAperture(self.dia, unit=self.unit)
+        yield PadStackAperture(copper_aperture, 'top', 'copper')
+        yield PadStackAperture(copper_aperture, 'bottom', 'copper')
+        yield PadStackAperture(copper_aperture, 'inner', 'copper')
+        if self.tented:
+            yield PadStackAperture(copper_aperture, 'top', 'mask')
+            yield PadStackAperture(copper_aperture, 'bottom', 'mask')
+        yield PadStackAperture(ExcellonTool(self.hole, plated=True, unit=self.unit), 'drill', 'plated')
+
+
+@dataclass(frozen=True, slots=True)
+class Via(FrozenPositioned):
+    pad_stack: PadStack
+
+    def render(self, layer_stack, cache=None):
+        x, y, rotation, flip = self.abs_pos
+        self.pad_stack.render(layer_stack, x, y, rotation, flip)
+
+    @classmethod
+    def at(kls, x, y, hole, dia=None, tented=True, unit=MM):
+        return kls(x, y, ThroughViaStack(hole, dia, tented, unit=unit), unit=unit)
+
+
+@dataclass
+class Pad(Positioned):
+    pad_stack: PadStack
+
+    def render(self, layer_stack, cache=None):
+        x, y, rotation, flip = self.abs_pos
+        self.pad_stack.render(layer_stack, x, y, rotation, flip)
+
+    @property
+    def single_sided(self):
+        return self.pad_stack.single_sided
+
+
+@dataclass
+class Trace:
+    width: float
+    start: object = None
+    end: object = None
+    waypoints: [(float, float)] = field(default_factory=list)
+    style: str = 'oblique'
+    orientation: [str] = tuple() # 'cw' or 'ccw'
+    roundover: float = 0
+    side: str = 'top'
+    unit: LengthUnit = MM
+    parent: object = None
+
+    DIRECT = 'direct'
+    OBLIQUE = 'oblique'
+    ORTHO = 'ortho'
+
+    CW = 'cw'
+    CCW = 'ccw'
+
+    def _route(self, p1, p2, orientation):
+        x1, y1 = p1
+        x2, y2 = p2
+        dx = x2-x1
+        dy = y2-y1
+
+        yield p1
+
+        if self.style == 'direct' or \
+                math.isclose(x1, x2, abs_tol=1e-6) or math.isclose(y1, y2, abs_tol=1e-6) or \
+                (self.style == 'oblique' and math.isclose(dx, dy, abs_tol=1e-6)):
+            return
+
+        p = (abs(dy) > abs(dx)) == ((dx >= 0) == (dy >= 0))
+        if self.style == 'oblique':
+            if p == (orientation == 'cw'):
+                if abs(dy) > abs(dx):
+                    yield (x1, y1+sgn(dy)*(abs(dy)-abs(dx)))
+                else:
+                    yield (x1+sgn(dx)*(abs(dx)-abs(dy)), y1)
+            else:
+                if abs(dy) > abs(dx):
+                    yield (x2, y1+sgn(dy)*abs(dx))
+                else:
+                    yield (x1+sgn(dx)*abs(dy), y2)
+
+        else: # self.style == 'ortho'
+            if p == (orientation == 'cw'):
+                if abs(dy) > abs(dx):
+                    yield (x1, y2)
+                else:
+                    yield (x2, y1)
+            else:
+                if abs(dy) > abs(dx):
+                    yield (x2, y1)
+                else:
+                    yield (x1, y2)
+
+    @classmethod
+    def _midpoint(kls, p1, p2):
+        x1, y1 = p1
+        x2, y2 = p2
+        dx = x2 - x1
+        dy = y2 - y1
+        xm = x1 + dx / 2
+        ym = y1 + dy / 2
+        return (xm, ym)
+
+    @classmethod
+    def _point_on_line(kls, p1, p2, dist_from_p1):
+        x1, y1 = p1
+        x2, y2 = p2
+        dx = x2 - x1
+        dy = y2 - y1
+        dist = math.dist(p1, p2)
+        if math.isclose(dist, 0, abs_tol=1e-6):
+            return p2
+        xm = x1 + dx / dist * dist_from_p1
+        ym = y1 + dy / dist * dist_from_p1
+        return (xm, ym)
+
+    @classmethod
+    def _angle_between(kls, p1, p2, p3):
+        x1, y1 = p1
+        x2, y2 = p2
+        x3, y3 = p3
+        x1, y1 = x1 - x2, y1 - y2
+        x3, y3 = x3 - x2, y3 - y2
+        dot_product = x1*x3 + y1*y3
+        l1 = math.hypot(x1, y1)
+        l2 = math.hypot(x3, y3)
+        norm = dot_product / l1 / l2
+        return math.acos(min(1, max(-1, norm)))
+
+    def _round_over(self, points, aperture):
+        if math.isclose(self.roundover, 0, abs_tol=1e-6) or len(points) <= 2:
+            import sys
+            for p1, p2 in zip(points[:-1], points[1:]):
+                yield Line(*p1, *p2, aperture=aperture, unit=self.unit)
+            return
+        # here: len(points) >= 3
+
+        line_b = Line(*points[0], *self._midpoint(points[0], points[1]), aperture=aperture, unit=self.unit)
+
+        for p1, p2, p3 in zip(points[:-2], points[1:-1], points[2:]):
+            x1, y1 = p1
+            x2, y2 = p2
+            x3, y3 = p3
+            xa, ya = pa = self._midpoint(p1, p2)
+            xb, yb = pb = self._midpoint(p2, p3)
+            la = math.dist(pa, p2)
+            lb = math.dist(p2, pb)
+
+            alpha = self._angle_between(p1, p2, p3)
+            if alpha == 0:
+                l = Line(line_b.x1, line_b.y1, *p2, aperture=aperture, unit=self.unit)
+                line_b = Line(*p2, *pb, aperture=aperture, unit=self.unit)
+                yield l
+                continue
+            tr = self.roundover/math.tan(alpha/2)
+            t = min(la, lb, tr)
+            r = t*math.tan(alpha/2)
+
+            xs, ys = ps = self._point_on_line(p2, pa, t)
+            xe, ye = pe = self._point_on_line(p2, pb, t)
+
+            if math.isclose(t, la, abs_tol=1e-6):
+                if not math.isclose(line_b.curve_length(), 0, abs_tol=1e-6):
+                    yield line_b
+                xs, ys = ps = pa
+            else:
+                yield Line(line_b.x1, line_b.y1, xs, ys, aperture=aperture, unit=self.unit)
+
+            if math.isclose(t, lb, abs_tol=1e-6):
+                xe, ye = pe = pb
+            line_b = Line(*pe, *pb, aperture=aperture, unit=self.unit)
+
+            if math.isclose(r, 0, abs_tol=1e-6):
+                continue
+
+            xc = -(y2 - ys) / t * r
+            yc = +(x2 - xs) / t * r
+
+            xsr = xs - x2
+            ysr = ys - y2
+            xer = xe - x2
+            yer = ye - y2
+            cross_product_z = xsr * yer - ysr * xer
+
+            clockwise = cross_product_z > 0
+            if clockwise:
+                xc, yc = -xc, -yc
+            
+            yield Arc(*ps, *pe, xc, yc, clockwise, aperture=aperture, unit=self.unit)
+
+        yield Line(line_b.x1, line_b.y1, x3, y3, aperture=aperture, unit=self.unit)
+        
+    def to_graphic_objects(self):
+        start, end = self.start, self.end
+
+        if not isinstance(start, tuple):
+            *start, _rotation, _flip = start.abs_pos
+        if not isinstance(end, tuple):
+            *end, _rotation, _flip = end.abs_pos
+
+        aperture = CircleAperture(diameter=self.width, unit=self.unit)
+
+        points_in = [start, *self.waypoints, end]
+
+        points = []
+        for p1, p2, orientation in zip_longest(points_in[:-1], points_in[1:], self.orientation):
+            points.extend(self._route(p1, p2, orientation))
+        points.append(p2)
+
+        return self._round_over(points, aperture)
+
+    def render(self, layer_stack, cache=None):
+        layer_stack[self.side, 'copper'].objects.extend(self.to_graphic_objects())
+
+def _route_demo():
+    from ..utils import setup_svg, Tag
+
+    def pd_obj(objs):
+        objs = list(objs)
+        yield f'M {objs[0].x1}, {objs[0].y1}'
+        for obj in objs:
+            if isinstance(obj, Line):
+                yield f'L {obj.x2}, {obj.y2}'
+            else:
+                assert isinstance(obj, Arc)
+                yield svg_arc(obj.p1, obj.p2, obj.center_relative, obj.clockwise)
+
+    pd = lambda points: f'M {points[0][0]}, {points[0][1]} ' + ' '.join(f'L {x}, {y}' for x, y in points[1:])
+
+    font = Newstroke()
+
+    tags = []
+    for n in range(0, 8*6):
+        theta = 2*math.pi / (8*6) * n
+        dx, dy = math.cos(theta), math.sin(theta)
+
+        strokes = list(font.render(f'α={n/(8*6)*360}', size=0.2))
+        xs = [x for st in strokes for x, _y in st]
+        ys = [y for st in strokes for _x, y in st]
+        min_x, min_y, max_x, max_y = min(xs), min(ys), max(xs), max(ys)
+
+        xf = f'translate({n//6*1.1 + 0.1} {n%6*1.3 + 0.3}) scale(0.5 0.5) translate(1 1)'
+        txf = f'{xf} translate(0 -1.2) translate({-(max_x-min_x)/2} {-max_y})'
+
+        tags.append(Tag('circle', cx='0', cy='0', r='1',
+                        fill='none', stroke='black', opacity='0.5', stroke_width='0.01',
+                        transform=xf))
+        tags.append(Tag('path',
+                        fill='none',
+                        stroke='black', opacity='0.5', stroke_width='0.02', stroke_linejoin='round', stroke_linecap='round',
+                        transform=txf, d=' '.join(pd(points) for points in strokes)))
+
+        #for r in [0.0, 0.1, 0.2, 0.3]:
+        for r in [0, 0.2]:
+            #tr = Trace(0.1, style='ortho', roundover=r, start=(0, 0), end=(dx, dy))
+            tr = Trace(0.1, style='oblique', roundover=r, start=(dx, dy), end=(0, 0))
+            #points_cw = list(tr._route((0, 0), (dx, dy), 'cw')) + [(dx, dy)]
+            #points_ccw = list(tr._route((0, 0), (dx, dy), 'ccw')) + [(dx, dy)]
+            tr.orientation = ['cw']
+            objs_cw = tr._to_graphic_objects()
+            tr.orientation = ['ccw']
+            objs_ccw = tr._to_graphic_objects()
+
+            tags.append(Tag('path',
+                            fill='none',
+                            stroke='red', stroke_width='0.01', stroke_linecap='round',
+                            transform=xf, d=' '.join(pd_obj(objs_cw))))
+            tags.append(Tag('path',
+                            fill='none',
+                            stroke='blue', stroke_width='0.01', stroke_linecap='round',
+                            transform=xf, d=' '.join(pd_obj(objs_ccw))))
+            #tags.append(Tag('path',
+            #                fill='none',
+            #                stroke='red', stroke_width='0.01', stroke_linecap='round',
+            #                transform=xf, d=pd(points_cw)))
+            #tags.append(Tag('path',
+            #                fill='none',
+            #                stroke='blue', stroke_width='0.01', stroke_linecap='round',
+            #                transform=xf, d=pd(points_ccw)))
+
+
+    print(setup_svg([Tag('g', tags, transform='scale(20 20)')], [(0, 0), (20*10*1.1 + 0.1, 20*10*1.3 + 0.1)]))
+
+
+def _board_demo():
+    b = Board(100, 80)
+    p1 = THTPad.rect(10, 10, 0.9, 1.8)
+    b.add(p1)
+    p2 = THTPad.rect(20, 15, 0.9, 1.8)
+    b.add(p2)
+    b.add(Trace(0.5, p1, p2, style='ortho', roundover=1.5))
+    b.add_text(50, 50, 'Foobar')
+    print(b.pretty_svg())
+    b.layer_stack().save_to_directory('/tmp/testdir')
+
+
+if __name__ == '__main__':
+    _board_demo()
+    #_route_demo()
+

src/gerbonara/cad/protoserve.py

@@ -0,0 +1,199 @@
+#!/usr/bin/env python
+
+import importlib.resources
+from tempfile import NamedTemporaryFile, TemporaryDirectory
+from pathlib import Path
+
+from quart import Quart, request, Response, send_file, abort
+
+from . import protoboard as pb
+from . import protoserve_data
+from .primitives import SMDStack
+from ..utils import MM, Inch
+
+
+def extract_importlib(package):
+    root = TemporaryDirectory()
+
+    stack = [(importlib.resources.files(package), Path(root.name))]
+    while stack:
+        res, out = stack.pop()
+
+        for item in res.iterdir():
+            item_out = out / item.name
+            if item.is_file():
+                item_out.write_bytes(item.read_bytes())
+            else:
+                assert item.is_dir()
+                item_out.mkdir()
+                stack.append((item, item_out))
+
+    return root
+
+static_folder = extract_importlib(protoserve_data)
+app = Quart(__name__, static_folder=static_folder.name)
+
+@app.route('/')
+async def index():
+    return await app.send_static_file('protoserve.html')
+
+def deserialize(obj, unit):
+    pitch_x = float(obj.get('pitch_x', 1.27))
+    pitch_y = float(obj.get('pitch_y', 1.27))
+    clearance = float(obj.get('clearance', 0.2))
+
+    mil = lambda x: x/1000 if unit == Inch else x
+
+    match obj['type']:
+        case 'layout':
+            if not obj.get('children'):
+                return pb.EmptyProtoArea()
+
+            proportions = [float(child['layout_prop']) for child in obj['children']]
+            content = [deserialize(child, unit) for child in obj['children']]
+            return pb.PropLayout(content, obj['direction'], proportions)
+
+        case 'twoside':
+            top, bottom = obj['children']
+            return pb.TwoSideLayout(deserialize(top, unit), deserialize(bottom, unit))
+
+        case 'placeholder':
+            return pb.EmptyProtoArea()
+
+        case 'smd':
+            match obj['pad_shape']:
+                case 'rect':
+                    stack = SMDStack.rect(pitch_x-clearance, pitch_y-clearance, paste=False, unit=unit)
+                case 'circle':
+                    stack = SMDStack.circle(min(pitch_x, pitch_y)-clearance, paste=False, unit=unit)
+            return pb.PatternProtoArea(pitch_x, pitch_y, obj=stack, unit=unit)
+
+        case 'tht':
+            hole_dia = mil(float(obj['hole_dia']))
+            match obj['plating']:
+                case 'plated':
+                    oneside, plated = False, True
+                case 'nonplated':
+                    oneside, plated = False, False
+                case 'singleside':
+                    oneside, plated = True, False
+
+            match obj['pad_shape']:
+                case 'rect':
+                    pad = pb.THTPad.rect(hole_dia, pitch_x-clearance, pitch_y-clearance, paste=False, plated=plated, unit=unit)
+                case 'circle':
+                    pad = pb.THTPad.circle(hole_dia, min(pitch_x, pitch_y)-clearance, paste=False, plated=plated, unit=unit)
+                case 'obround':
+                    pad = pb.THTPad.obround(hole_dia, pitch_x-clearance, pitch_y-clearance, paste=False, plated=plated, unit=unit)
+
+            if oneside:
+                pad.pad_bottom = None
+
+            return pb.PatternProtoArea(pitch_x, pitch_y, obj=pad, unit=unit)
+
+        case 'manhattan':
+            return pb.PatternProtoArea(pitch_x, pitch_y, obj=pb.ManhattanPads(pitch_x, pitch_y, clearance, unit=unit), unit=unit)
+
+        case 'powered':
+            pitch = mil(float(obj.get('pitch', 2.54)))
+            hole_dia = mil(float(obj['hole_dia']))
+            via_drill = mil(float(obj['via_hole_dia']))
+            via_dia = mil(float(obj['via_dia']))
+            trace_width = mil(float(obj['trace_width']))
+            # Force 1mm margin to avoid shorts when adjacent to planes such as that one in the RF THT proto.
+            return pb.PatternProtoArea(pitch, pitch, pb.PoweredProto(pitch, hole_dia, clearance, via_size=via_drill, power_pad_dia=via_dia, trace_width=trace_width, unit=unit), margin=unit(1.0, MM), unit=unit)
+
+        case 'flower':
+            pitch = mil(float(obj.get('pitch', 2.54)))
+            hole_dia = mil(float(obj['hole_dia']))
+            pattern_dia = mil(float(obj['pattern_dia']))
+            clearance = mil(float(obj['clearance']))
+            return pb.PatternProtoArea(pitch, pitch, pb.THTFlowerProto(pitch, hole_dia, pattern_dia, clearance, unit=unit), unit=unit)
+
+        case 'spiky':
+            return pb.PatternProtoArea(2.54, 2.54, pb.SpikyProto(), unit=unit)
+
+        case 'alio':
+            pitch = mil(float(obj.get('pitch', 2.54)))
+            drill = mil(float(obj.get('hole_dia', 0.9)))
+            clearance = mil(float(obj.get('clearance', 0.3)))
+            link_pad_width = mil(float(obj.get('link_pad_width', 1.1)))
+            link_trace_width = mil(float(obj.get('link_trace_width', 0.5)))
+            via_size = mil(float(obj.get('via_hole_dia', 0.4)))
+            return pb.PatternProtoArea(pitch, pitch, pb.AlioCell(
+                    pitch=pitch,
+                    drill=drill,
+                    clearance=clearance,
+                    link_pad_width=link_pad_width,
+                    link_trace_width=link_trace_width,
+                    via_size=via_size
+                ), margin=unit(1.5, MM), unit=unit)
+
+        case 'breadboard':
+            horizontal = obj.get('direction', 'v') == 'h'
+            drill = float(obj.get('hole_dia', 0.9))
+            return pb.BreadboardArea(clearance=clearance, drill=drill, horizontal=horizontal, unit=unit)
+
+        case 'starburst':
+            trace_width_x = float(obj.get('trace_width_x', 1.8))
+            trace_width_y = float(obj.get('trace_width_y', 1.8))
+            drill = float(obj.get('hole_dia', 0.9))
+            annular_ring = float(obj.get('annular', 1.2))
+            clearance = float(obj.get('clearance', 0.4))
+            mask_width = float(obj.get('mask_width', 0.5))
+            return pb.PatternProtoArea(pitch_x, pitch_y, pb.StarburstPad(pitch_x, pitch_y, trace_width_x, trace_width_y, clearance, mask_width, drill, annular_ring, unit=unit), unit=unit)
+
+        case 'rf':
+            pitch = float(obj.get('pitch', 2.54))
+            hole_dia = float(obj['hole_dia'])
+            via_dia = float(obj['via_dia'])
+            via_drill = float(obj['via_hole_dia'])
+            return pb.PatternProtoArea(pitch, pitch, pb.RFGroundProto(pitch, hole_dia, clearance, via_dia, via_drill, unit=MM), unit=MM)
+
+def to_board(obj):
+    unit = Inch if obj.get('units' == 'us') else MM
+    w = float(obj.get('width', unit(100, MM)))
+    h = float(obj.get('height', unit(80, MM)))
+    corner_radius = float(obj.get('round_corners', {}).get('radius', unit(1.5, MM)))
+    margin = float(obj.get('margin', unit(2.0, MM)))
+    holes = obj.get('mounting_holes', {})
+    mounting_hole_dia = float(holes.get('diameter', unit(3.2, MM)))
+    mounting_hole_offset = float(holes.get('offset', unit(5, MM)))
+
+    if obj.get('children'):
+        try:
+            content = deserialize(obj['children'][0], unit)
+        except ValueError:
+            return abort(400)
+    else:
+        content = [pb.EmptyProtoArea()]
+
+    return pb.ProtoBoard(w, h, content,
+                       corner_radius=corner_radius,
+                       mounting_hole_dia=mounting_hole_dia,
+                       mounting_hole_offset=mounting_hole_offset,
+                       margin=margin,
+                       unit=unit)
+
+@app.route('/preview_<side>.svg', methods=['POST'])
+async def preview(side):
+    obj = await request.get_json()
+    board = to_board(obj)
+    return Response(str(board.pretty_svg(side=side)), mimetype='image/svg+xml')
+
+@app.route('/gerbers.zip', methods=['POST'])
+async def gerbers():
+    obj = await request.get_json()
+    board = to_board(obj)
+    with NamedTemporaryFile(suffix='.zip') as f:
+        f = Path(f.name)
+        board.layer_stack().save_to_zipfile(f)
+        return Response(f.read_bytes(), mimetype='image/svg+xml')
+
+def main():
+    app.run()
+
+
+if __name__ == '__main__':
+    main()
+

src/gerbonara/cam.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -22,8 +22,11 @@ from dataclasses import dataclass
 from copy import deepcopy
 from enum import Enum
 import string
+import shutil
+from pathlib import Path
+from functools import cached_property
 
-from .utils import LengthUnit, MM, Inch, Tag
+from .utils import LengthUnit, MM, Inch, Tag, sum_bounds, setup_svg, convex_hull
 from . import graphic_primitives as gp
 from . import graphic_objects as go
 
@@ -41,17 +44,29 @@ class FileSettings:
     #: (relative) mode is technically still supported, but exceedingly rare in the wild.
     notation : str = 'absolute'
     #: Export unit. :py:attr:`~.utilities.MM` or :py:attr:`~.utilities.Inch`
-    unit : LengthUnit = MM
+    unit : LengthUnit = None
     #: Angle unit. Should be ``'degree'`` unless you really know what you're doing.
     angle_unit : str = 'degree'
-    #: Zero suppression settings. See note at :py:class:`.FileSettings` for meaning.
+    #: Zero suppression settings. Must be one of ``None``, ``'leading'`` or ``'trailing'``. See note at
+    #: :py:class:`.FileSettings` for meaning in Excellon files. ``None`` will produce explicit decimal points, which
+    #: should work for most tools. For Gerber files, the other settings are fine, but for Excellon files, which lack a
+    #: standardized way to indicate number format, explicit decimal points are the best way to avoid mis-parsing.
     zeros : bool = None
     #: Number format. ``(integer, decimal)`` tuple of number of integer and decimal digits. At most ``(6,7)`` by spec.
-    number_format : tuple = (2, 5)
+    number_format : tuple = (None, None)
+    #: At least the aperture macro implementations of gerbv and whatever JLCPCB uses are severely broken and simply
+    #: ignore parentheses in numeric expressions without throwing an error or a warning, leading to broken rendering.
+    #: To avoid trouble with severely broken software like this, we just calculate out all macros by default.
+    #: If you want to export the macros with their original formulaic expressions (which is completely fine by the
+    #: Gerber standard, btw), set this parameter to ``False`` before exporting.
+    calculate_out_all_aperture_macros: bool = True
+    #: Internal field used to communicate if only decimal coordinates were found inside an Excellon file, or if it
+    #: contained at least some coordinates in fixed-width notation.
+    _file_has_fixed_width_coordinates: bool = False
 
     # input validation
     def __setattr__(self, name, value):
-        if name == 'unit' and value not in [MM, Inch]:
+        if name == 'unit' and value not in [None, MM, Inch]:
             raise ValueError(f'Unit must be either Inch or MM, not {value}')
         elif name == 'notation' and value not in ['absolute', 'incremental']:
             raise ValueError(f'Notation must be either "absolute" or "incremental", not {value}')
@@ -72,6 +87,13 @@ class FileSettings:
             num = self.number_format[1 if self.zeros == 'leading' else 0] or 0
             self._pad = '0'*num
 
+    @classmethod
+    def defaults(kls):
+        """ Return a set of good default settings that will work for all gerber or excellon files. These default
+        settings are metric units, 4 integer digits (for up to 10 m by 10 m size), 5 fractional digits (for 10 µm
+        resolution) and :py:obj:`None` zero suppression, meaning that explicit decimal points are going to be used."""
+        return FileSettings(unit=MM, number_format=(4,5), zeros=None)
+
     def to_radian(self, value):
         """ Convert a given numeric string or a given float from file units into radians. """
         value = float(value)
@@ -110,13 +132,16 @@ class FileSettings:
 
     @property
     def is_metric(self):
+        """ Return true if this :py:class:`.FileSettings` has a defined unit, and that unit is :py:attr:`~.utilities.MM` """
         return self.unit == MM
 
     @property
     def is_inch(self):
+        """ Return true if this :py:class:`.FileSettings` has a defined unit, and that unit is :py:attr:`~.utilities.Inch` """
         return self.unit == Inch
 
     def copy(self):
+        """ Create a deep copy of this FileSettings """
         return deepcopy(self)
 
     def __str__(self):
@@ -138,8 +163,8 @@ class FileSettings:
 
         if '.' in value or value == '00':
             return float(value)
-
-        integer_digits, decimal_digits = self.number_format
+ 
+        integer_digits, decimal_digits = self.number_format or (2, 5)
 
         if self.zeros == 'leading':
             value = self._pad + value # pad with zeros to ensure we have enough decimals
@@ -155,7 +180,7 @@ class FileSettings:
         if unit is not None:
             value = self.unit(value, unit)
         
-        integer_digits, decimal_digits = self.number_format
+        integer_digits, decimal_digits = self.number_format or (2, 5)
         if integer_digits is None:
             integer_digits = 3
         if decimal_digits is None:
@@ -185,7 +210,7 @@ class FileSettings:
         if unit is not None:
             value = self.unit(value, unit)
         
-        integer_digits, decimal_digits = self.number_format
+        integer_digits, decimal_digits = self.number_format or (2, 5)
         if integer_digits is None:
             integer_digits = 2
         if decimal_digits is None:
@@ -231,9 +256,11 @@ class Polyline:
             return None
 
         (x0, y0), *rest = self.coords
-        d = f'M {x0:.6} {y0:.6} ' + ' '.join(f'L {x:.6} {y:.6}' for x, y in rest)
-        width = f'{self.width:.6}' if not math.isclose(self.width, 0) else '0.01mm'
-        return tag('path', d=d, style=f'fill: none; stroke: {color}; stroke-width: {width}; stroke-linejoin: round; stroke-linecap: round')
+        d = f'M {float(x0):.6} {float(y0):.6} ' + ' '.join(f'L {float(x):.6} {float(y):.6}' for x, y in rest)
+        width = f'{float(self.width):.6}' if not math.isclose(self.width, 0) else '0.01mm'
+        return tag('path', d=d,
+                   fill='none', stroke=color, stroke_linecap='round', stroke_linejoin='round',
+                   stroke_width=width)
 
 
 class CamFile:
@@ -246,77 +273,57 @@ class CamFile:
         self.layer_name = layer_name
         self.import_settings = import_settings
 
+    @property
+    def is_lazy(self):
+        return False
+
+    @property
+    def instance(self):
+        return self
+
     def to_svg(self, margin=0, arg_unit=MM, svg_unit=MM, force_bounds=None, fg='black', bg='white', tag=Tag):
-
-        if force_bounds is None:
-            (min_x, min_y), (max_x, max_y) = self.bounding_box(svg_unit, default=((0, 0), (0, 0)))
+        if force_bounds:
+            bounds = svg_unit.convert_bounds_from(arg_unit, force_bounds)
         else:
-            (min_x, min_y), (max_x, max_y) = force_bounds
-            min_x = svg_unit(min_x, arg_unit)
-            min_y = svg_unit(min_y, arg_unit)
-            max_x = svg_unit(max_x, arg_unit)
-            max_y = svg_unit(max_y, arg_unit)
+            bounds = self.bounding_box(svg_unit, default=((0, 0), (0, 0)))
 
-        content_min_x, content_min_y = min_x, min_y
-        content_w, content_h = max_x - min_x, max_y - min_y
-        if margin:
-            margin = svg_unit(margin, arg_unit)
-            min_x -= margin
-            min_y -= margin
-            max_x += margin
-            max_y += margin
+        tags = list(self.svg_objects(svg_unit=svg_unit, tag=tag, fg=fg, bg=bg))
 
-        w, h = max_x - min_x, max_y - min_y
-        w = 1.0 if math.isclose(w, 0.0) else w
-        h = 1.0 if math.isclose(h, 0.0) else h
+        # setup viewport transform flipping y axis
+        (content_min_x, content_min_y), (content_max_x, content_max_y) = bounds
+        content_min_x, content_min_y = float(content_min_x), float(content_min_y)
+        content_max_x, content_max_y = float(content_max_x), float(content_max_y)
+        content_w, content_h = content_max_x - content_min_x, content_max_y - content_min_y
+        xform = f'translate({float(content_min_x):.6} {float(content_min_y+content_h):.6}) scale(1 -1) translate({-float(content_min_x):.6} {-float(content_min_y):.6})'
+        tags = [tag('g', tags, transform=xform)]
 
-        view = tag('sodipodi:namedview', [], id='namedview1', pagecolor=bg,
-                inkscape__document_units=svg_unit.shorthand)
+        return setup_svg(tags, bounds, margin=margin, arg_unit=arg_unit, svg_unit=svg_unit,
+                pagecolor=bg, tag=tag)
 
-        tags = []
+    def svg_objects(self, svg_unit=MM, fg='black', bg='white', aperture_map={}, tag=Tag):
         pl = None
         for i, obj in enumerate(self.objects):
-            #if isinstance(obj, go.Flash):
-            #    if pl:
-            #        tags.append(pl.to_svg(tag, fg, bg))
-            #        pl = None
+            if isinstance(obj, go.Flash) and id(obj.aperture) in aperture_map:
+                yield tag('use', href='#'+aperture_map[id(obj.aperture)],
+                          x=f'{svg_unit(obj.x, obj.unit):.3f}',
+                          y=f'{svg_unit(obj.y, obj.unit):.3f}')
 
-            #    mask_tags = [ prim.to_svg(tag, 'white', 'black') for prim in obj.to_primitives(unit=svg_unit) ]
-            #    mask_tags.insert(0, tag('rect', width='100%', height='100%', fill='black'))
-            #    mask_id = f'mask{i}'
-            #    tag('mask', mask_tags, id=mask_id)
-            #    tag('rect', width='100%', height='100%', mask='url(#{mask_id})', fill=fg)
-
-            #else:
+            else:
                 for primitive in obj.to_primitives(unit=svg_unit):
                     if isinstance(primitive, gp.Line):
                         if not pl:
                             pl = Polyline(primitive)
                         else:
                             if not pl.append(primitive):
-                                tags.append(pl.to_svg(fg, bg, tag=tag))
+                                yield pl.to_svg(fg, bg, tag=tag)
                                 pl = Polyline(primitive)
                     else:
                         if pl:
-                            tags.append(pl.to_svg(fg, bg, tag=tag))
+                            yield pl.to_svg(fg, bg, tag=tag)
                             pl = None
-                        tags.append(primitive.to_svg(fg, bg, tag=tag))
+                        yield primitive.to_svg(fg, bg, tag=tag)
         if pl:
-            tags.append(pl.to_svg(fg, bg, tag=tag))
-
-        # setup viewport transform flipping y axis
-        xform = f'translate({content_min_x} {content_min_y+content_h}) scale(1 -1) translate({-content_min_x} {-content_min_y})'
-
-        svg_unit = 'in' if svg_unit == 'inch' else 'mm'
-        # TODO export apertures as <uses> where reasonable.
-        return tag('svg', [view, tag('g', tags, transform=xform)],
-                width=f'{w}{svg_unit}', height=f'{h}{svg_unit}',
-                viewBox=f'{min_x} {min_y} {w} {h}',
-                xmlns="http://www.w3.org/2000/svg",
-                xmlns__xlink="http://www.w3.org/1999/xlink",
-                xmlns__sodipodi='http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd',
-                xmlns__inkscape='http://www.inkscape.org/namespaces/inkscape',
-                root=True)
+            yield pl.to_svg(fg, bg, tag=tag)
 
     def size(self, unit=MM):
         """ Get the dimensions of the file's axis-aligned bounding box, i.e. the difference in x- and y-direction
@@ -342,16 +349,25 @@ class CamFile:
         :rtype: tuple
         """
 
-        bounds = [ p.bounding_box(unit) for p in self.objects ]
-        if not bounds:
-            return default
+        return sum_bounds(( p.bounding_box(unit) for p in self.objects ), default=default)
 
-        min_x = min(x0 for (x0, y0), (x1, y1) in bounds)
-        min_y = min(y0 for (x0, y0), (x1, y1) in bounds)
-        max_x = max(x1 for (x0, y0), (x1, y1) in bounds)
-        max_y = max(y1 for (x0, y0), (x1, y1) in bounds)
+    def convex_hull(self, tol=0.01, unit=None):
+        unit = unit or self.unit
+        points = []
 
-        return ((min_x, min_y), (max_x, max_y))
+        for obj in self.objects:
+            if isinstance(obj, go.Line):
+                line = obj.as_primitive(unit)
+                points.append((line.x1, line.y1))
+                points.append((line.x2, line.y2))
+
+            elif isinstance(obj, go.Arc):
+                for obj in obj.approximate(tol, unit):
+                    line = obj.as_primitive(unit)
+                    points.append((line.x1, line.y1))
+                    points.append((line.x2, line.y2))
+
+        return convex_hull(points)
 
     def to_excellon(self):
         """ Convert to a :py:class:`.ExcellonFile`. Returns ``self`` if it already is one. """
@@ -364,7 +380,7 @@ class CamFile:
     def merge(self, other):
         """ Merge ``other`` into ``self``, i.e. add all objects that are in ``other`` to ``self``. This resets
         :py:attr:`.import_settings` and :py:attr:`~.CamFile.generator`. Units and other file-specific settings are
-        automatically handled.
+        handled automatically.
         """
         raise NotImplementedError()
 
@@ -405,6 +421,16 @@ class CamFile:
         """
         raise NotImplementedError()
 
+    def scale(self, factor, unit=MM):
+        """ Scale all objects in this file by the given factor. Only uniform scaling using a single factor in both
+        directions is supported as for both Gerber and Excellon files, nonuniform scaling would distort circular
+        flashes, which would lead to garbage results.
+
+        :param float factor: Scale factor
+        :param unit: :py:class:`.LengthUnit` or str (``'mm'`` or ``'inch'``). Unit ``cx`` and ``cy`` are passed in. Default: mm
+        """
+        raise NotImplementedError()
+
     @property
     def is_empty(self):
         """ Check if there are any objects in this file. """
@@ -419,3 +445,30 @@ class CamFile:
         """ Test if this file contains any objects """
         return not self.is_empty
 
+class LazyCamFile:
+    """ Helper class for :py:class:`~.layers.LayerStack` that holds a path to an input file without loading it right
+    away. This class'es :py:method:`save` method will just copy the input file instead of parsing and re-serializing
+    it."""
+    def __init__(self, klass, path, *args, **kwargs):
+        self._class = klass
+        self.original_path = Path(path)
+        self._args = args
+        self._kwargs = kwargs
+
+    @cached_property
+    def instance(self):
+        """ Load the input file if necessary, and return the loaded object. Will only load the file once, and cache the
+        result. """
+        return self._class.open(self.original_path, *self._args, **self._kwargs)
+
+    @property
+    def is_lazy(self):
+        return True
+
+    def save(self, filename, *args, **kwargs):
+        """ Copy this Gerber file to the new path. """
+        if 'instance' in self.__dict__: # instance has been loaded, and might have been modified
+            self.instance.save(filename, *args, **kwargs)
+        else:
+            shutil.copy(self.original_path, filename)
+

src/gerbonara/cli.py

@@ -0,0 +1,601 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2023 Jan Sebastian Götte <gerbonara@jaseg.de>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+
+import math
+import click
+import dataclasses
+import re
+import warnings
+import json
+import sys
+import itertools
+import webbrowser
+import warnings
+from pathlib import Path
+
+from .utils import MM, Inch
+from .cam import FileSettings
+from .rs274x import GerberFile
+from . import layers as lyr
+from . import __version__
+from .cad.kicad import schematic as kc_schematic
+from .cad.kicad import tmtheme
+from .cad import protoserve
+
+
+def _showwarning(message, category, filename, lineno, file=None, line=None):
+    if file is None:
+        file = sys.stderr
+
+    filename = Path(filename)
+    gerbonara_module_install_location = Path(__file__).parent.parent
+    if filename.is_relative_to(gerbonara_module_install_location):
+        filename = filename.relative_to(gerbonara_module_install_location)
+
+    print(f'{filename}:{lineno}: {message}', file=file)
+warnings.showwarning = _showwarning
+
+def _print_version(ctx, param, value):
+    if value and not ctx.resilient_parsing:
+        click.echo(f'Version {__version__}')
+        ctx.exit()
+
+
+def _apply_transform(transform, unit, layer_or_stack):
+    def translate(x, y):
+        layer_or_stack.offset(x, y, unit)
+
+    def scale(factor):
+        """ Scale layer by a given factor, e.g. 1.0 for no change, 2.0 to double all coordinates in both axes. Note that
+        we only offer uniform scaling with a single factor applied along both coordinate axes because anything else
+        would not be possible with arbitrary Gerber apertures, and definitely mess up holes. We could still do this, but
+        the result would almost certainly not be what the user is looking for.
+
+        The main reason why this function might make sense is to fix up boards exported as G-code by programs that
+        aren't EDA tools and that for whatever reason ended up exporting in a weird unit."""
+        layer_or_stack.scale(factor)
+
+    def rotate(angle, cx=0, cy=0):
+        layer_or_stack.rotate(math.radians(angle), cx, cy, unit)
+
+    (x_min, y_min), (x_max, y_max) = layer_or_stack.bounding_box(unit, default=((0, 0), (0, 0)))
+    width, height = x_max - x_min, y_max - y_min
+
+    def origin():
+        translate(-x_min, -y_min)
+
+    def center():
+        translate(-x_min-width/2, -y_min-height/2)
+
+    exec(transform, {key: value for key, value in math.__dict__.items() if not key.startswith('_')}, locals())
+
+
+class Coordinate(click.ParamType):
+    name = 'coordinate'
+
+    def __init__(self, dimension=2):
+        self.dimension = dimension
+    
+    def convert(self, value, param, ctx):
+        try:
+            coords = [float(e) for e in value.split(',')]
+            if len(coords) != self.dimension:
+                raise ValueError()
+            return coords
+
+        except ValueError:
+            self.fail(f'{value!r} is not a valid coordinate. A coordinate consists of exactly {self.dimension} comma-separate floating-point numbers.')
+
+class Rotation(click.ParamType):
+    name = 'rotation'
+
+    def convert(self, value, param, ctx):
+        try:
+            coords = [float(e) for e in value.split(',')]
+            if len(coords) not in (1, 3):
+                raise ValueError()
+
+            theta, x, y, *_rest = *coords, 0, 0
+            return theta, x, y
+
+        except ValueError:
+            self.fail(f'{value!r} is not a valid rotation. A rotation is either a floating point angle ("[theta]"), or the same angle followed by comma-separated X and Y coordinates of the rotation center ("[theta],[cx],[cy]").')
+
+
+class Unit(click.Choice):
+    name = 'unit'
+
+    def __init__(self):
+        super().__init__(['metric', 'us-customary'])
+
+    def convert(self, value, param, ctx):
+        value = super().convert(value, param, ctx)
+        return MM if value == 'metric' else Inch
+
+
+class NamingScheme(click.Choice):
+    name = 'naming_scheme'
+
+    def __init__(self):
+        super().__init__([n for n in dir(lyr.NamingScheme) if not n.startswith('_')])
+
+    def convert(self, value, param, ctx):
+        return getattr(lyr.NamingScheme, super().convert(value, param, ctx))
+
+
+@click.group()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+def cli():
+    """ The gerbonara CLI allows you to analyze, render, modify and merge both individual Gerber or Excellon files as
+    well as sets of those files """
+    pass
+
+@cli.group('protoboard')
+def protoboard_group():
+    pass
+
+
+@protoboard_group.command()
+@click.option('-h', '--host', default=None, help='Hostname to listen on. Defaults to localhost.')
+@click.option('-p', '--port', type=int, default=1337, help='Port to listen on. Defaults to 1337')
+def interactive(host, port):
+    ''' Launch gerbonar's interactive protoboard designer in your browser '''
+    
+    if host is None:
+        @protoserve.app.before_serving
+        async def open_browser():
+            webbrowser.open_new(f'http://localhost:{port}/')
+    protoserve.app.run(host=host, port=port, use_reloader=False, debug=False)
+
+
+@cli.group('kicad')
+def kicad_group():
+    pass
+
+
+@kicad_group.group('schematic')
+def schematic_group():
+    pass
+
+
+@schematic_group.command()
+@click.argument('inpath', type=click.Path(exists=True))
+@click.argument('theme', type=click.Path(exists=True))
+@click.argument('outfile', type=click.File('w'), default='-')
+def render(inpath, theme, outfile):
+    sch = kc_schematic.Schematic.open(inpath)
+    cs = tmtheme.TmThemeSchematic(Path(theme).read_text())
+    with outfile as f:
+        f.write(str(sch.to_svg(cs)))
+
+
+@cli.command()
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('-m', '--input-map', type=click.Path(exists=True, path_type=Path), help='''Extend or override layer name
+              mapping with name map from JSON file. The JSON file must contain a single JSON dict with an arbitrary
+              number of string: string entries. The keys are interpreted as regexes applied to the filenames via
+              re.fullmatch, and each value must either be the string "ignore" to remove this layer from previous
+              automatic guesses, or a gerbonara layer name such as "top copper", "inner_2 copper" or "bottom silk".''')
+@click.option('--use-builtin-name-rules/--no-builtin-name-rules', default=True, help='''Disable built-in layer name
+              rules and use only rules given by --input-map''')
+@click.option('--force-zip', is_flag=True, help='''Force treating input path as a zip file (default: guess file type
+              from extension and contents)''')
+@click.option('--top', 'side', flag_value='top', help='Render top side')
+@click.option('--bottom', 'side', flag_value='bottom', help='Render top side')
+@click.option('--command-line-units', type=Unit(), help='''Units for values given in other options. Default:
+              millimeter''')
+@click.option('--margin', type=float, default=0.0, help='Add space around the board inside the viewport')
+@click.option('--force-bounds', help='Force SVG bounding box to value given as "min_x,min_y,max_x,max_y"')
+@click.option('--inkscape/--standard-svg', default=True, help='Export in Inkscape SVG format with layers and stuff.')
+@click.option('--pretty/--no-filters', default=True, help='''Export pseudo-realistic render using filters (default) or
+              just stack up layers using given colorscheme. In "--no-filters" mode, by default all layers are exported
+              unless either "--top" or "--bottom" is given.''')
+@click.option('--drills/--no-drills', default=True, help='''Include (default) or exclude drills ("--no-filters" only!)''')
+@click.option('--colorscheme', type=click.Path(exists=True, path_type=Path), help='''Load colorscheme from given JSON
+              file. The JSON file must contain a single dict with keys copper, silk, mask, paste, drill and outline.
+              Each key must map to a string containing either a normal 6-digit hex color with leading hash sign, or an
+              8-digit hex color with leading hash sign, where the last two digits set the layer's alpha value (opacity),
+              with FF being completely opaque, and 00 being invisibly transparent.''')
+@click.argument('inpath', type=click.Path(exists=True))
+@click.argument('outfile', type=click.File('w'), default='-')
+def render(inpath, outfile, format_warnings, input_map, use_builtin_name_rules, force_zip, side, drills,
+           command_line_units, margin, force_bounds, inkscape, pretty, colorscheme):
+    """ Render a gerber file, or a directory or zip of gerber files into an SVG file. """
+
+    overrides = json.loads(input_map.read_bytes()) if input_map else None
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        if force_zip:
+            stack = lyr.LayerStack.open_zip(inpath, overrides=overrides, autoguess=use_builtin_name_rules)
+        else:
+            stack = lyr.LayerStack.open(inpath, overrides=overrides, autoguess=use_builtin_name_rules)
+
+    if force_bounds:
+        min_x, min_y, max_x, max_y = list(map(float, force_bounds.split(',')))
+        force_bounds = (min_x, min_y), (max_x, max_y)
+
+    if colorscheme:
+        colorscheme = json.loads(colorscheme.read_text())
+
+    if pretty:
+        svg = stack.to_pretty_svg(side='bottom' if side == 'bottom' else 'top', margin=margin,
+                                              arg_unit=(command_line_units or MM),
+                          svg_unit=MM, force_bounds=force_bounds, inkscape=inkscape, colors=colorscheme)
+    else:
+        svg = stack.to_svg(side_re=side or '.*', margin=margin, drills=drills, arg_unit=(command_line_units or MM),
+                          svg_unit=MM, force_bounds=force_bounds, colors=colorscheme)
+    outfile.write(str(svg))
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('-t', '--transform', help='''Execute python transformation script on input. You have access to the
+              functions translate(x, y), scale(factor) and rotate(angle, center_x?, center_y?), the bounding box
+              variables x_min, y_min, x_max, y_max, width and height, and everything from python\'s built-in math module
+              (e.g. pi, sqrt, sin). As convenience methods, center() and origin() are provided to center the board resp.
+              move its bottom-left corner to the origin. Coordinates are given in --command-line-units, angles in
+              degrees, and scale as a scale factor (as opposed to a percentage). Example: "translate(-10, 0); rotate(45,
+              0, 5)"''')
+@click.option('--command-line-units', type=Unit(), help='''Units for values given in other options. Default:
+              millimeter''')
+@click.option('-n', '--number-format', help='''Override number format to use during export in "[integer digits].[decimal
+              digits]" notation, e.g. "2.6".''')
+@click.option('-u', '--units', type=Unit(), help='Override export file units')
+@click.option('-z', '--zero-suppression', type=click.Choice(['off', 'leading', 'trailing']), help='''Override export
+              zero suppression setting. Note: The meaning of this value is like in the Gerber spec for both Gerber and
+              Excellon files!''')
+@click.option('--keep-comments/--drop-comments', help='''Keep gerber comments. Note: Comments will be prepended to the
+              start of file, and will not occur in their old position.''')
+@click.option('--reuse-input-settings', 'output_format', flag_value='reuse', help='''Use the same export settings as the
+              input file instead of sensible defaults.''')
+@click.option('--default-settings', 'output_format', default=True, flag_value='defaults', help='''Use sensible defaults
+              for the output file format settings (default).''')
+@click.option('--input-number-format', help='Override number format of input file (mostly useful for Excellon files)')
+@click.option('--input-units', type=Unit(), help='Override units of input file')
+@click.option('--input-zero-suppression', type=click.Choice(['off', 'leading', 'trailing']), help='''Override zero
+              suppression setting of input file''')
+@click.argument('infile')
+@click.argument('outfile')
+def rewrite(transform, command_line_units, number_format, units, zero_suppression, keep_comments, output_format,
+            input_number_format, input_units, input_zero_suppression, infile, outfile, format_warnings):
+    """ Parse a single gerber file, apply transformations, and re-serialize it into a new gerber file. Without
+    transformations, this command can be used to convert a gerber file to use different settings (e.g. units,
+    precision), but can also be used to "normalize" gerber files in a weird format into a more standards-compatible one
+    as gerbonara's gerber parser is significantly more robust for weird inputs than others. """
+
+    input_settings = FileSettings()
+    if input_number_format:
+        a, _, b = input_number_format.partition('.')
+        input_settings.number_format = (int(a), int(b))
+
+    if input_zero_suppression:
+        input_settings.zeros = None if input_zero_suppression == 'off' else input_zero_suppression
+
+    input_settings.unit = input_units
+
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        f = GerberFile.open(infile, override_settings=input_settings)
+
+    if transform:
+        _apply_transform(transform, command_line_units or MM, f)
+
+    output_format = f.import_settings if output_format == 'reuse' else FileSettings.defaults()
+    if number_format:
+        a, _, b = number_format.partition('.')
+        output_format.number_format = (int(a), int(b))
+
+    if units:
+        output_format.unit = units
+
+    if zero_suppression:
+        output_format.zeros = None if zero_suppression == 'off' else zero_suppression
+
+    f.save(outfile, output_format, not keep_comments)
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('-m', '--input-map', type=click.Path(exists=True, path_type=Path), help='''Extend or override layer name
+              mapping with name map from JSON file. The JSON file must contain a single JSON dict with an arbitrary
+              number of string: string entries. The keys are interpreted as regexes applied to the filenames via
+              re.fullmatch, and each value must either be the string "ignore" to remove this layer from previous
+              automatic guesses, or a gerbonara layer name such as "top copper", "inner_2 copper" or "bottom silk".''')
+@click.option('--use-builtin-name-rules/--no-builtin-name-rules', default=True, help='''Disable built-in layer name
+              rules and use only rules given by --input-map''')
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('--units', type=Unit(), help='Units for values given in other options. Default: millimeter')
+@click.option('-n', '--number-format', help='''Override number format to use during export in
+              "[integer digits].[decimal digits]" notation, e.g. "2.6".''')
+@click.option('--reuse-input-settings', 'output_format', flag_value='reuse', help='''Use the same export settings as the
+              input file instead of sensible defaults.''')
+@click.option('--default-settings', 'output_format', default=True, flag_value='defaults', help='''Use sensible defaults
+              for the output file format settings (default).''')
+@click.option('--force-zip', is_flag=True, help='''Force treating input path as a zip file (default: guess file type
+              from extension and contents)''')
+@click.option('--output-naming-scheme', type=NamingScheme(), help=f'''Name output files according to the selected naming
+              scheme instead of keeping the old file names.''')
+@click.argument('transform')
+@click.argument('inpath')
+@click.argument('outpath', type=click.Path(path_type=Path))
+def transform(transform, units, output_format, inpath, outpath, format_warnings, input_map, use_builtin_name_rules,
+              output_naming_scheme, number_format, force_zip):
+    """ Transform all gerber files in a given directory or zip file using the given python transformation script.
+        
+        In the python transformation script you have access to the functions translate(x, y), scale(factor) and
+        rotate(angle, center_x?, center_y?), the bounding box variables x_min, y_min, x_max, y_max, width and height,
+        and everything from python\'s built-in math module (e.g. pi, sqrt, sin). As convenience methods, center() and
+        origin() are provided to center the board resp. move its bottom-left corner to the origin. Coordinates are given
+        in --command-line-units, angles in degrees, and scale as a scale factor (as opposed to a percentage). Example:
+        "translate(-10, 0); rotate(45, 0, 5)"''')
+    """
+
+    overrides = json.loads(input_map.read_bytes()) if input_map else None
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        if force_zip:
+            stack = lyr.LayerStack.open_zip(inpath, overrides=overrides, autoguess=use_builtin_name_rules)
+        else:
+            stack = lyr.LayerStack.open(inpath, overrides=overrides, autoguess=use_builtin_name_rules)
+
+    _apply_transform(transform, units, stack)
+
+    output_format = None if output_format == 'reuse' else FileSettings.defaults()
+    if number_format:
+        if output_format is None:
+            output_format = FileSettings.defaults()
+        a, _, b = number_format.partition('.')
+        output_format.number_format = (int(a), int(b))
+    if outpath.is_file() or outpath.suffix.lower() == '.zip':
+        stack.save_to_zipfile(outpath, naming_scheme=output_naming_scheme or {},
+                                gerber_settings=output_format,
+                                excellon_settings=dataclasses.replace(output_format, zeros=None))
+    else:
+        stack.save_to_directory(outpath, naming_scheme=output_naming_scheme or {},
+                                gerber_settings=output_format,
+                                excellon_settings=dataclasses.replace(output_format, zeros=None))
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('--command-line-units', type=Unit(), help='''Units for values given in --transform. Default:
+              millimeter''')
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('--offset', multiple=True, type=Coordinate(), help="""Offset for the n'th file as a "x,y" string in unit
+              given by --command-line-units (default: millimeter). Can be given multiple times, and the first option
+              affects the first input, the second option affects the second input, and so on.""")
+@click.option('--rotation', multiple=True, type=Rotation(), help="""Rotation for the n'th file in degrees clockwise,
+              optionally followed by comma-separated rotation center X and Y coordinates. Can be given multiple times,
+              and the first option affects the first input, the second option affects the second input, and so on.""")
+@click.option('-m', '--input-map', type=click.Path(exists=True, path_type=Path), multiple=True, help='''Extend or
+              override layer name mapping with name map from JSON file. This option can be given multiple times, in
+              which case the n'th option affects only the n'th input, like with --offset and --rotation. The JSON file
+              must contain a single JSON dict with an arbitrary number of string: string entries. The keys are
+              interpreted as regexes applied to the filenames via re.fullmatch, and each value must either be the string
+              "ignore" to remove this layer from previous automatic guesses, or a gerbonara layer name such as "top
+              copper", "inner_2 copper" or "bottom silk".''')
+@click.option('--reuse-input-settings', 'output_format', flag_value='reuse', help='''Use the same export settings as the
+              input file instead of sensible defaults.''')
+@click.option('--default-settings', 'output_format', default=True, flag_value='defaults', help='''Use sensible defaults
+              for the output file format settings (default).''')
+@click.option('--output-naming-scheme', type=NamingScheme(), help=f'''Name output files according to the selected naming
+              scheme instead of keeping the old file names of the first input.''')
+@click.option('--output-board-name', help=f'''Override board name used with --output-naming-scheme''')
+@click.option('--use-builtin-name-rules/--no-builtin-name-rules', default=True, help='''Disable built-in layer name
+              rules and use only rules given by --input-map''')
+@click.argument('inpath', nargs=-1, type=click.Path(exists=True, path_type=Path))
+@click.argument('outpath', type=click.Path(path_type=Path))
+def merge(inpath, outpath, offset, rotation, input_map, command_line_units, output_format, output_naming_scheme,
+          output_board_name, format_warnings, use_builtin_name_rules):
+    """ Merge multiple single Gerber or Excellon files, or multiple stacks of Gerber files, into one. Hint: When used
+    with only one input, this command "normalizes" the input, converting all files to a well-defined, widely supported
+    Gerber subset with sane settings. When a --output-naming-scheme is given, it additionally renames all files to a
+    standardized naming convention. """
+    if not inpath:
+        return
+
+    target = None
+    for p, offset, rotation, input_map in itertools.zip_longest(inpath, offset, rotation, input_map):
+        if p is None:
+            raise click.UsageError('More --offset, --rotation or --input-map options than input files')
+
+        offset = offset or (0, 0)
+        theta, cx, cy = rotation or (0, 0, 0)
+
+        overrides = json.loads(input_map.read_bytes()) if input_map else None
+        with warnings.catch_warnings():
+            warnings.simplefilter(format_warnings)
+
+            stack = lyr.LayerStack.open(p, overrides=overrides, autoguess=use_builtin_name_rules)
+
+            if not math.isclose(offset[0], 0, abs_tol=1e-3) and math.isclose(offset[1], 0, abs_tol=1e-3):
+                stack.offset(*offset, command_line_units or MM)
+
+            if not math.isclose(theta, 0, abs_tol=1e-2):
+                stack.rotate(theta, cx, cy)
+
+            if target is None:
+                target = stack
+            else:
+                target.merge(stack)
+
+    if output_board_name:
+        if not output_naming_scheme:
+            warnings.warn('--output-board-name given without --output-naming-scheme. This will be ignored.')
+        target.board_name = output_board_name
+    output_format = None if output_format == 'reuse' else FileSettings.defaults()
+    target.save_to_directory(outpath, naming_scheme=output_naming_scheme or {},
+                            gerber_settings=output_format,
+                            excellon_settings=dataclasses.replace(output_format, zeros=None))
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('--units', type=Unit(), default='metric', help='Output bounding box in this unit (default: millimeter)')
+@click.option('--input-number-format', help='Override number format of input file (mostly useful for Excellon files)')
+@click.option('--input-units', type=Unit(), help='Override units of input file')
+@click.option('--input-zero-suppression', type=click.Choice(['off', 'leading', 'trailing']), help='Override zero suppression setting of input file')
+@click.argument('infile')
+def bounding_box(infile, format_warnings, input_number_format, input_units, input_zero_suppression, units):
+    """ Print the bounding box of a gerber file in "[x_min] [y_min] [x_max] [y_max]" format. The bounding box contains
+    all graphic objects in this file, so e.g. a 100 mm by 100 mm square drawn with a 1mm width circular aperture will
+    result in an 101 mm by 101 mm bounding box.
+    """
+
+    input_settings = FileSettings()
+    if input_number_format:
+        a, _, b = input_number_format.partition('.')
+        input_settings.number_format = (int(a), int(b))
+
+    if input_zero_suppression:
+        input_settings.zeros = None if input_zero_suppression == 'off' else input_zero_suppression
+
+    input_settings.unit = input_units
+
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        f = GerberFile.open(infile, override_settings=input_settings)
+
+    (x_min, y_min), (x_max, y_max) = f.bounding_box(unit=units)
+    print(f'{x_min:.6f} {y_min:.6f} {x_max:.6f} {y_max:.6f} [{units}]')
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), default='default',
+              help='''Enable or disable file format warnings during parsing (default: on)''')
+@click.option('--force-zip', is_flag=True, help='Force treating input path as zip file (default: guess file type from extension and contents)')
+@click.argument('path', type=click.Path(exists=True))
+def layers(path, force_zip, format_warnings):
+    """ Read layers from a directory or zip with Gerber files and list the found layer / path assignment. """ 
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        if force_zip:
+            stack = lyr.LayerStack.open_zip(path)
+        else:
+            stack = lyr.LayerStack.open(path)
+
+    print(f'Detected board name: {stack.board_name}')
+    print(f'Probably exported by: {stack.generator or "Unknown"}')
+    print(f'Board bounding box: {stack.bounding_box()} [mm]')
+
+    if stack.netlist:
+        print(f'Found netlist at {stack.netlist.original_path}')
+    else:
+        print('No netlist found')
+
+    print('Graphical layers:')
+    for (side, function), layer in stack.graphic_layers.items():
+        print(f'{side} {function}: {layer}')
+    if not stack.graphic_layers:
+        print('(no graphical layers)')
+
+    print('Drill layers:')
+    for layer in stack.drill_layers:
+        print(layer)
+    if not stack.drill_layers:
+        print('(no drill layers)')
+
+
+@cli.command()
+@click.option('--version', is_flag=True, callback=_print_version, expose_value=False, is_eager=True)
+@click.option('--warnings', 'format_warnings', type=click.Choice(['default', 'ignore', 'once']), help='''Enable or
+              disable file format warnings during parsing (default: on)''')
+@click.option('--force-zip', is_flag=True, help='Force treating input path as zip file (default: guess file type from extension and contents)')
+@click.argument('path', type=click.Path(exists=True))
+def meta(path, force_zip, format_warnings):
+    """ Extract layer mapping and print it along with layer metadata as JSON to stdout. A machine-readable variant of
+    the "layers" command. All lengths in the JSON are given in millimeter. """
+
+    with warnings.catch_warnings():
+        warnings.simplefilter(format_warnings)
+        if force_zip:
+            stack = lyr.LayerStack.open_zip(path)
+        else:
+            stack = lyr.LayerStack.open(path)
+
+    out = {}
+    out['board_name'] = stack.board_name
+    out['generator'] = stack.generator
+    (min_x, min_y), (max_x, max_y) = stack.bounding_box(default=((None, None), (None, None)))
+    out['bounding_box'] = {'min_x': min_x, 'min_y': min_y, 'max_x': max_x, 'max_y': max_y}
+    out['path'] = str(stack.original_path)
+
+    if stack.netlist:
+        out['netlist'] = {
+                'format': 'IPC-356',
+                'path': str(stack.netlist.original_path),
+                'records': len(stack.netlist.test_records),
+                'conductors': len(stack.netlist.conductors),
+                'outlines': len(stack.netlist.outlines),
+        }
+
+    out['graphical_layers'] = {}
+    for (side, function), layer in stack.graphic_layers.items():
+        d = out['graphical_layers'][side] = out['graphical_layers'].get(side, {})
+        (min_x, min_y), (max_x, max_y) = layer.bounding_box(default=((None, None), (None, None)))
+
+        if layer.import_settings:
+            numf = layer.import_settings.number_format
+            format_settings = {
+                'unit': str(layer.import_settings.unit),
+                'number_format': f'{numf[0]}.{numf[1]}' if numf else None,
+                'zero_suppression': str(layer.import_settings.zeros),
+            }
+
+        d[function] = {
+                'format': 'Gerber',
+                'path': str(layer.original_path),
+                'apertures': len(list(layer.apertures())),
+                'objects': len(layer.objects),
+                'bounding_box': {'min_x': min_x, 'min_y': min_y, 'max_x': max_x, 'max_y': max_y},
+                'format_settings': format_settings,
+        }
+
+    out['drill_layers'] = []
+    for layer in stack.drill_layers:
+        if layer.import_settings:
+            numf = layer.import_settings.number_format
+            format_settings = {
+                'unit': str(layer.import_settings.unit),
+                'number_format': f'{numf[0]}.{numf[1]}' if numf else None,
+                'zero_suppression': str(layer.import_settings.zeros),
+            }
+
+        out['drill_layers'].append({
+            'format': 'Excellon',
+            'path': str(layer.original_path),
+            'plating': layer.plating_type,
+            'format_settings': format_settings,
+        })
+
+    print(json.dumps(out))
+
+
+if __name__ == '__main__':
+    cli()
+

src/gerbonara/excellon.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -30,9 +30,10 @@ from pathlib import Path
 
 from .cam import CamFile, FileSettings
 from .graphic_objects import Flash, Line, Arc
-from .apertures import ExcellonTool
+from .apertures import ExcellonTool, CircleAperture
 from .utils import Inch, MM, to_unit, InterpMode, RegexMatcher
 
+
 class ExcellonContext:
     """ Internal helper class used for tracking graphics state when writing Excellon. """
 
@@ -46,13 +47,15 @@ class ExcellonContext:
 
     def select_tool(self, tool):
         """ Select the current tool. Retract drill first if necessary. """
-        if self.current_tool != tool:
+        current_id = self.tools.get(self.current_tool)
+        new_id = self.tools[tool]
+        if new_id != current_id:
             if self.drill_down:
                 yield 'M16' # drill up
                 self.drill_down = False
 
             self.current_tool = tool
-            yield f'T{self.tools[id(tool)]:02d}'
+            yield f'T{new_id:02d}'
 
     def drill_mode(self):
         """ Enter drill mode. """
@@ -162,6 +165,8 @@ def parse_allegro_logfile(data):
     return found_tools
 
 def parse_zuken_logfile(data):
+    """ Internal function to parse Excellon format information out of Zuken's nonstandard textual log files that their
+    tools generate along with the Excellon file. """
     lines = [ line.strip() for line in data.splitlines() ]
     if '*****  DRILL LIST  *****' not in lines:
         return # likely not a Zuken CR-8000 logfile 
@@ -207,19 +212,22 @@ class ExcellonFile(CamFile):
 
     def __str__(self):
         name = f'{self.original_path.name} ' if self.original_path else ''
-        if self.is_plated:
-            plating = 'plated'
-        elif self.is_nonplated:
-            plating = 'nonplated'
-        elif self.is_mixed_plating:
-            plating = 'mixed plating'
-        else:
-            plating = 'unknown plating'
-        return f'<ExcellonFile {name}{plating} with {len(list(self.drills()))} drills, {len(list(self.slots()))} slots using {len(self.drill_sizes())} tools>'
+        return f'<ExcellonFile {name}{self.plating_type} with {len(list(self.drills()))} drills, {len(list(self.slots()))} slots using {len(self.drill_sizes())} tools>'
 
     def __repr__(self):
         return str(self)
 
+    @property
+    def plating_type(self):
+        if self.is_plated:
+            return 'plated'
+        elif self.is_nonplated:
+            return 'nonplated'
+        elif self.is_mixed_plating:
+            return 'mixed plating'
+        else:
+            return 'unknown plating'
+
     @property
     def is_plated(self):
         """ Test if *all* holes or slots in this file are plated. """
@@ -240,41 +248,57 @@ class ExcellonFile(CamFile):
         """ Test if there are multiple plating values used in this file. """
         return len({obj.plated for obj in self.objects}) > 1
 
+    @property
+    def is_plated_tristate(self):
+        if self.is_plated:
+            return True
+
+        if self.is_nonplated:
+            return False
+
+        return None
+
     def append(self, obj_or_comment):
         """ Add a :py:class:`.GraphicObject` or a comment (str) to this file. """
-        if isinstnace(obj_or_comment, str):
+        if isinstance(obj_or_comment, str):
             self.comments.append(obj_or_comment)
         else:
             self.objects.append(obj_or_comment)
 
-    def to_excellon(self):
+    def to_excellon(self, plated=None, errors='raise'):
+        """ Counterpart to :py:meth:`~.rs274x.GerberFile.to_excellon`. Does nothing and returns :py:obj:`self`. """
         return self
 
-    def to_gerber(self):
-        apertures = {}
+    def to_gerber(self, errors='raise'):
+        """ Convert this excellon file into a :py:class:`~.rs274x.GerberFile`. """
+        from .rs274x import GerberFile
         out = GerberFile()
         out.comments = self.comments
 
+        apertures = {}
         for obj in self.objects:
-            if id(obj.tool) not in apertures:
-                apertures[id(obj.tool)] = CircleAperture(obj.tool.diameter)
+            if not (ap := apertures.get(obj.tool)):
+                ap = apertures[obj.tool] = CircleAperture(obj.tool.diameter, unit=obj.aperture.unit)
 
-            out.objects.append(dataclasses.replace(obj, aperture=apertures[id(obj.tool)]))
-
-        out.apertures = list(apertures.values())
+            out.objects.append(dataclasses.replace(obj, aperture=ap))
+        return out
 
     @property
     def generator(self):
         return self.generator_hints[0] if self.generator_hints else None
 
-    def merge(self, other):
+    def merge(self, other, mode='ignored', keep_settings=False):
         if other is None:
             return
+        
+        if not isinstance(other, ExcellonFile):
+            other = other.to_excellon(plated=self.is_plated_tristate)
 
         self.objects += other.objects
         self.comments += other.comments
         self.generator_hints = None
-        self.import_settings = None
+        if not keep_settings:
+            self.import_settings = None
 
     @classmethod
     def open(kls, filename, plated=None, settings=None, external_tools=None):
@@ -304,7 +328,7 @@ class ExcellonFile(CamFile):
             for fn in 'nc_param.txt', 'ncdrill.log':
                 if (param_file := filename.parent / fn).is_file():
                     settings =  parse_allegro_ncparam(param_file.read_text())
-                    warnings.warn(f'Loaded allegro-style excellon settings file {param_file}')
+                    warnings.warn(f'Loaded allegro-style excellon settings file {param_file}', SyntaxWarning)
                     break
 
             # Parse Zuken log file for settings
@@ -312,7 +336,7 @@ class ExcellonFile(CamFile):
                 logfile = filename.with_suffix('.fdl')
                 if logfile.is_file():
                     settings = parse_zuken_logfile(logfile.read_text())
-                    warnings.warn(f'Loaded zuken-style excellon log file {logfile}: {settings}')
+                    warnings.warn(f'Loaded zuken-style excellon log file {logfile}: {settings}', SyntaxWarning)
 
         if external_tools is None:
             # Parse allegro log files for tools.
@@ -350,27 +374,36 @@ class ExcellonFile(CamFile):
         yield 'METRIC' if settings.unit == MM else 'INCH'
 
         # Build tool index
-        tool_map = { id(obj.tool): obj.tool for obj in self.objects }
+        tool_map = { obj.tool: obj.tool for obj in self.objects }
         tools = sorted(tool_map.items(), key=lambda id_tool: (id_tool[1].plated, id_tool[1].diameter))
-        tools = { tool_id: index for index, (tool_id, _tool) in enumerate(tools, start=1) }
-        # FIXME dedup tools
 
         mixed_plating = (len({ tool.plated for tool in tool_map.values() }) > 1)
         if mixed_plating:
-            warnings.warn('Multiple plating values in same file. Will use non-standard Altium comment syntax to indicate hole plating.')
+            warnings.warn('Multiple plating values in same file. Will use non-standard Altium comment syntax to indicate hole plating.', SyntaxWarning)
 
-        if tools and max(tools.values()) >= 100:
-            warnings.warn('More than 99 tools defined. Some programs may not like three-digit tool indices.', SyntaxWarning)
+        defined_tools = {}
+        tool_indices = {}
+        index = 1
+        for tool_id, tool in tools:
+            xnc = tool.to_xnc(settings)
+            if (tool.plated, xnc) in defined_tools:
+                tool_indices[tool_id] = defined_tools[(tool.plated, xnc)]
 
-        for tool_id, index in tools.items():
-            tool = tool_map[tool_id]
-            if mixed_plating:
-                yield ';TYPE=PLATED' if tool.plated else ';TYPE=NON_PLATED'
-            yield f'T{index:02d}' + tool.to_xnc(settings)
+            else:
+                if mixed_plating:
+                    yield ';TYPE=PLATED' if tool.plated else ';TYPE=NON_PLATED'
+
+                yield f'T{index:02d}' + xnc
+
+                tool_indices[tool_id] = defined_tools[(tool.plated, xnc)] = index
+                index += 1
+
+                if index >= 100:
+                    warnings.warn('More than 99 tools defined. Some programs may not like three-digit tool indices.', SyntaxWarning)
 
         yield '%'
 
-        ctx = ExcellonContext(settings, tools)
+        ctx = ExcellonContext(settings, tool_indices)
 
         # Export objects
         for obj in self.objects:
@@ -378,7 +411,7 @@ class ExcellonFile(CamFile):
 
         yield 'M30'
 
-    def generate_excellon(self, settings=None, drop_comments=True):
+    def write_to_bytes(self, settings=None, drop_comments=True):
         """ Export to Excellon format. This function always generates XNC, which is a well-defined subset of Excellon.
         Uses sane default settings if you don't give any.
 
@@ -393,17 +426,17 @@ class ExcellonFile(CamFile):
         if settings is None:
             if self.import_settings:
                 settings = self.import_settings.copy()
+                settings.zeros = None
+                settings.number_format = (3,5)
             else:
-                settings = FileSettings()
-            settings.zeros = None
-            settings.number_format = (3,5)
-        return '\n'.join(self._generate_statements(settings, drop_comments=drop_comments))
+                settings = FileSettings.defaults()
+        return '\n'.join(self._generate_statements(settings, drop_comments=drop_comments)).encode('utf-8')
 
     def save(self, filename, settings=None, drop_comments=True):
         """ Save this Excellon file to the file system. See :py:meth:`~.ExcellonFile.generate_excellon` for the meaning
         of the arguments. """
-        with open(filename, 'w') as f:
-            f.write(self.generate_excellon(settings, drop_comments=drop_comments))
+        with open(filename, 'wb') as f:
+            f.write(self.write_to_bytes(settings, drop_comments=drop_comments))
 
     def offset(self, x=0, y=0, unit=MM):
         for obj in self.objects:
@@ -536,6 +569,8 @@ class ExcellonParser(object):
         self.filename = None
         self.external_tools = external_tools or {}
         self.found_kicad_format_comment = False
+        self.allegro_eof_toolchange_hack = False
+        self.allegro_eof_toolchange_hack_index = 1
 
     def warn(self, msg):
         warnings.warn(f'{self.filename}:{self.lineno} "{self.line}": {msg}', SyntaxWarning)
@@ -576,18 +611,25 @@ class ExcellonParser(object):
     exprs = RegexMatcher()
 
     # NOTE: These must be kept before the generic comment handler at the end of this class so they match first.
-    @exprs.match(r';T(?P<index1>[0-9]+) Holesize (?P<index2>[0-9]+)\. = (?P<diameter>[0-9/.]+) Tolerance = \+[0-9/.]+/-[0-9/.]+ (?P<plated>PLATED|NON_PLATED|OPTIONAL) (?P<unit>MILS|MM) Quantity = [0-9]+')
+    @exprs.match(r';(?P<index1_prefix>T(?P<index1>[0-9]+))?\s+Holesize (?P<index2>[0-9]+)\. = (?P<diameter>[0-9/.]+) Tolerance = \+[0-9/.]+/-[0-9/.]+ (?P<plated>PLATED|NON_PLATED|OPTIONAL) (?P<unit>MILS|MM) Quantity = [0-9]+')
     def parse_allegro_tooldef(self, match):
         # NOTE: We ignore the given tolerances here since they are non-standard.
         self.program_state = ProgramState.HEADER # TODO is this needed? we need a test file.
         self.generator_hints.append('allegro')
 
-        if (index := int(match['index1'])) != int(match['index2']): # index1 has leading zeros, index2 not.
+        index = int(match['index2'])
+
+        if match['index1'] and index != int(match['index1']): # index1 has leading zeros, index2 not.
             raise SyntaxError('BUG: Allegro excellon tool def has mismatching tool indices. Please file a bug report on our issue tracker and provide this file!')
 
         if index in self.tools:
             self.warn('Re-definition of tool index {index}, overwriting old definition.') 
 
+        if not match['index1_prefix']:
+            # This is a really nasty orcad file without tool change commands, that instead just puts all holes in order
+            # of the hole size definitions with M00's in between.
+            self.allegro_eof_toolchange_hack = True
+
         # NOTE: We map "optionally" plated holes to plated holes for API simplicity. If you hit a case where that's a
         # problem, please raise an issue on our issue tracker, explain why you need this and provide an example file.
         is_plated = None if match['plated'] is None else (match['plated'] in ('PLATED', 'OPTIONAL'))
@@ -600,13 +642,19 @@ class ExcellonParser(object):
         else:
             unit = MM
 
-        if unit != self.settings.unit:
+        if self.settings.unit is None:
+            self.settings.unit = unit
+
+        elif unit != self.settings.unit:
             self.warn('Allegro Excellon drill file tool definitions in {unit.name}, but file parameters say the '
                     'file should be in {settings.unit.name}. Please double-check that this is correct, and if it is, '
                     'please raise an issue on our issue tracker.')
 
         self.tools[index] = ExcellonTool(diameter=diameter, plated=is_plated, unit=unit)
 
+        if self.allegro_eof_toolchange_hack and self.active_tool is None:
+            self.active_tool = self.tools[index]
+
     # Searching Github I found that EasyEDA has two different variants of the unit specification here.
     @exprs.match(';Holesize (?P<index>[0-9]+) = (?P<diameter>[.0-9]+) (?P<unit>INCH|inch|METRIC|mm)')
     def parse_easyeda_tooldef(self, match):
@@ -723,6 +771,12 @@ class ExcellonParser(object):
     def handle_end_of_program(self, match):
         if self.program_state in (None, ProgramState.HEADER):
             self.warn('M30 statement found before end of header.')
+
+        if self.allegro_eof_toolchange_hack:
+            self.allegro_eof_toolchange_hack_index = min(max(self.tools), self.allegro_eof_toolchange_hack_index + 1)
+            self.active_tool = self.tools[self.allegro_eof_toolchange_hack_index]
+            return
+
         self.program_state = ProgramState.FINISHED
         # TODO: maybe add warning if this is followed by other commands.
 
@@ -732,14 +786,17 @@ class ExcellonParser(object):
     def do_move(self, coord_groups):
         x_s, x, y_s, y = coord_groups
 
-        if self.settings.number_format == (None, None) and '.' not in x:
-            # TARGET3001! exports zeros as "00" even when it uses an explicit decimal point everywhere else.
-            if x != '00':
-                raise SyntaxError('No number format set and value does not contain a decimal point. If this is an Allegro '
-                    'Excellon drill file make sure either nc_param.txt or ncdrill.log ends up in the same folder as '
-                    'it, because Allegro does not include this critical information in their Excellon output. If you '
-                    'call this through ExcellonFile.from_string, you must manually supply from_string with a '
-                    'FileSettings object from excellon.parse_allegro_ncparam.')
+        if (x is not None and '.' not in x) or (y is not None and '.' not in y):
+            self.settings._file_has_fixed_width_coordinates = True
+
+            if self.settings.number_format == (None, None):
+                # TARGET3001! exports zeros as "00" even when it uses an explicit decimal point everywhere else.
+                if x != '00':
+                    raise SyntaxError('No number format set and value does not contain a decimal point. If this is an Allegro '
+                        'Excellon drill file make sure either nc_param.txt or ncdrill.log ends up in the same folder as '
+                        'it, because Allegro does not include this critical information in their Excellon output. If you '
+                        'call this through ExcellonFile.from_string, you must manually supply from_string with a '
+                        'FileSettings object from excellon.parse_allegro_ncparam.')
 
         x = self.settings.parse_gerber_value(x)
         if x_s:
@@ -833,12 +890,17 @@ class ExcellonParser(object):
                 # from https://math.stackexchange.com/a/1781546
                 if a_s:
                     raise ValueError('Negative arc radius given')
-                r = settings.parse_gerber_value(a)
+                r = self.settings.parse_gerber_value(a)
                 x1, y1 = start
                 x2, y2 = end
                 dx, dy = (x2-x1)/2, (y2-y1)/2
                 x0, y0 = x1+dx, y1+dy
-                f = math.hypot(dx, dy) / math.sqrt(r**2 - a**2)
+                d = math.hypot(dx, dy)
+                if d == 0:
+                    raise ValueError('Arc radius notation requires distinct start and end points')
+                if r < d:
+                    raise ValueError('Arc radius too small for endpoint distance')
+                f = math.sqrt(r**2 - d**2) / d
                 if clockwise:
                     cx = x0 + f*dy
                     cy = y0 - f*dx
@@ -848,16 +910,16 @@ class ExcellonParser(object):
                 i, j = cx-start[0], cy-start[1]
 
             else: # explicit center given
-                i = settings.parse_gerber_value(i)
+                i = self.settings.parse_gerber_value(i) or 0
                 if i_s:
                     i = -i
-                j = settings.parse_gerber_value(j)
+                j = self.settings.parse_gerber_value(j) or 0
                 if j_s:
-                    j = -i
+                    j = -j
 
-            self.objects.append(Arc(*start, *end, i, j, True, self.active_tool, unit=self.settings.unit))
+            self.objects.append(Arc(*start, *end, i, j, clockwise, self.active_tool, unit=self.settings.unit))
 
-    @exprs.match(r'(M71|METRIC|M72|INCH)(,LZ|,TZ)?(,0*\.0*)?')
+    @exprs.match(r'(M71|METRIC|M72|INCH)(,LZ|,TZ)?(,([0-9]+\.[0-9]+|0*\.0*))?')
     def parse_easyeda_format(self, match):
         metric = match[1] in ('METRIC', 'M71')
 
@@ -870,7 +932,10 @@ class ExcellonParser(object):
         # This is used by newer autodesk eagles, fritzing and diptrace
         if match[3]:
             integer, _, fractional = match[3][1:].partition('.')
-            self.settings.number_format = len(integer), len(fractional)
+            if integer.strip('0') or fractional.strip('0'):
+                self.settings.number_format = int(integer), int(fractional)
+            else:
+                self.settings.number_format = len(integer), len(fractional)
 
         elif self.settings.number_format == (None, None) and not metric and not self.found_kicad_format_comment:
             self.warn('Using implicit number format from bare "INCH" statement. This is normal for Fritzing, Diptrace, Geda and pcb-rnd.')
@@ -896,10 +961,10 @@ class ExcellonParser(object):
     @exprs.match('(FMAT|VER),?([0-9]*)')
     def handle_command_format(self, match):
         if match[1] == 'FMAT':
-            # We do not support integer/fractional decimals specification via FMAT because that's stupid. If you need this,
-            # please raise an issue on our issue tracker, provide a sample file and tell us where on earth you found that
-            # file.
-            if match[2] not in ('', '2'):
+            # We only use FMAT as a compatibility marker. Version 1 drill files encountered in the wild still use the
+            # same coordinate and routing statements that we already support, so rejecting the header unconditionally
+            # needlessly breaks otherwise parseable files.
+            if match[2] not in ('', '1', '2'):
                 raise SyntaxError(f'Unsupported FMAT format version {match[2]}')
 
         else: # VER
@@ -928,6 +993,19 @@ class ExcellonParser(object):
         else:
             self.warn('Bare coordinate after end of file')
 
+    @exprs.match(xy_coord + 'G85' + xy_coord)
+    def handle_g85_slot(self, match):
+        if self.program_state == ProgramState.HEADER:
+            return
+
+        self.do_move(match.groups()[:4])
+        start, end = self.do_move(match.groups()[4:])
+
+        if not self.ensure_active_tool():
+            return
+
+        self.objects.append(Line(*start, *end, self.active_tool, unit=self.settings.unit))
+
     @exprs.match(r'DETECT,ON|ATC,ON|M06')
     def parse_zuken_legacy_statements(self, match):
         self.generator_hints.append('zuken')

src/gerbonara/graphic_objects.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -18,10 +18,12 @@
 
 import math
 import copy
-from dataclasses import dataclass, KW_ONLY, astuple, replace, field, fields
+from dataclasses import dataclass, astuple, field, fields
+from itertools import zip_longest, pairwise, islice, cycle
 
-from .utils import MM, InterpMode, to_unit, rotate_point
+from .utils import MM, InterpMode, to_unit, rotate_point, sum_bounds, approximate_arc, sweep_angle
 from . import graphic_primitives as gp
+from .aperture_macros import primitive as amp
 
 
 def convert(value, src, dst):
@@ -40,26 +42,35 @@ class Length:
         # This makes the automatically generated method signatures in the Sphinx docs look nice
         return 'float'
 
-@dataclass
 class GraphicObject:
     """ Base class for the graphic objects that make up a :py:class:`.GerberFile` or :py:class:`.ExcellonFile`. """
-    _ : KW_ONLY
 
-    #: bool representing the *color* of this feature: whether this is a *dark* or *clear* feature. Clear and dark are
-    #: meant in the sense that they are used in the Gerber spec and refer to whether the transparency film that this
-    #: file describes ends up black or clear at this spot. In a standard green PCB, a *polarity_dark=True* line will
-    #: show up as copper on the copper layer, white ink on the silkscreen layer, or an opening on the soldermask layer.
-    #: Clear features erase dark features, they are not transparent in the colloquial meaning. This property is ignored
-    #: for features of an :py:class:`.ExcellonFile`.
-    polarity_dark : bool = True
+    # hackety hack: Work around python < 3.10 not having dataclasses.KW_ONLY. Once we drop python 3.8 and 3.9, we can
+    # get rid of this, just set these as normal fields, and decorate GraphicObject with @dataclass.
+    # 
+    # See also: apertures.py, graphic_primitives.py
+    def __init_subclass__(cls):
+        #: bool representing the *color* of this feature: whether this is a *dark* or *clear* feature. Clear and dark are
+        #: meant in the sense that they are used in the Gerber spec and refer to whether the transparency film that this
+        #: file describes ends up black or clear at this spot. In a standard green PCB, a *polarity_dark=True* line will
+        #: show up as copper on the copper layer, white ink on the silkscreen layer, or an opening on the soldermask layer.
+        #: Clear features erase dark features, they are not transparent in the colloquial meaning. This property is ignored
+        #: for features of an :py:class:`.ExcellonFile`.
+        cls.polarity_dark = True
 
-    #: :py:class:`.LengthUnit` used for all coordinate fields of this object (such as ``x`` or ``y``).
-    unit : str = None
+        #: :py:class:`.LengthUnit` used for all coordinate fields of this object (such as ``x`` or ``y``).
+        cls.unit = None
 
+        #: `dict` containing GerberX2 attributes attached to this feature. Note that this does not include file attributes,
+        #: which are stored in the :py:class:`.GerberFile` object instead.
+        cls.attrs = field(default_factory=dict)
+
+        d = {'polarity_dark' : bool, 'unit' : str, 'attrs': dict}
+        if hasattr(cls, '__annotations__'):
+            cls.__annotations__.update(d)
+        else:
+            cls.__annotations__ = d
 
-    #: `dict` containing GerberX2 attributes attached to this feature. Note that this does not include file attributes,
-    #: which are stored in the :py:class:`.GerberFile` object instead.
-    attrs : dict = field(default_factory=dict)
 
     def converted(self, unit):
         """ Convert this gerber object to another :py:class:`.LengthUnit`.
@@ -96,6 +107,20 @@ class GraphicObject:
         dx, dy = self.unit(dx, unit), self.unit(dy, unit)
         self._offset(dx, dy)
 
+    def scale(self, factor, unit=MM):
+        """ Scale this feature in both its dimensions and location.
+
+        .. note:: The scale factor is a scalar, and the unit argument is irrelevant, but is kept for API consistency.
+        
+        .. note:: If this object references an aperture, this aperture is not modified. You will have to transform this
+                  aperture yourself.
+
+        :param float factor: Scale factor, 1 to keep the object as is, larger values to enlarge, smaller values to
+                             shrink. Negative values are permitted.
+        """
+
+        self._scale(factor)
+
     def rotate(self, rotation, cx=0, cy=0, unit=MM):
         """ Rotate this object. The center of rotation can be given in either unit, and is automatically converted into
         this object's local unit.
@@ -103,6 +128,9 @@ class GraphicObject:
         .. note:: The center's Y coordinate as well as the angle's polarity are flipped compared to computer graphics
                   convention since Gerber uses a bottom-to-top Y axis.
 
+        .. note:: If this object references an aperture, this aperture is not modified. You will have to transform this
+                  aperture yourself.
+
         :param float rotation: rotation in radians clockwise.
         :param float cx: X coordinate of center of rotation in *unit* units.
         :param float cy: Y coordinate of center of rotation. (0,0) is at the bottom left of the image.
@@ -124,12 +152,7 @@ class GraphicObject:
         :returns: tuple of tuples of floats: ``(min_x, min_y), (max_x, max_y)``
         """
 
-        bboxes = [ p.bounding_box() for p in self.to_primitives(unit) ]
-        min_x = min(min_x for (min_x, _min_y), _ in bboxes)
-        min_y = min(min_y for (_min_x, min_y), _ in bboxes)
-        max_x = max(max_x for _, (max_x, _max_y) in bboxes)
-        max_y = max(max_y for _, (_max_x, max_y) in bboxes)
-        return ((min_x, min_y), (max_x, max_y))
+        return sum_bounds(p.bounding_box() for p in self.to_primitives(unit))
 
     def to_primitives(self, unit=None):
         """ Render this object into low-level graphical primitives (subclasses of :py:class:`.GraphicPrimitive`). This
@@ -191,6 +214,11 @@ class Flash(GraphicObject):
     def tool(self, value):
         self.aperture = value
 
+    def bounding_box(self, unit=None):
+        (min_x, min_y), (max_x, max_y) = self.aperture.bounding_box(unit)
+        x, y = self.unit.convert_to(unit, self.x), self.unit.convert_to(unit, self.y)
+        return (min_x+x, min_y+y), (max_x+x, max_y+y)
+
     @property
     def plated(self):
         """ (Excellon only) Returns if this is a plated hole. ``True`` (plated), ``False`` (non-plated) or ``None``
@@ -205,6 +233,10 @@ class Flash(GraphicObject):
     def _rotate(self, rotation, cx=0, cy=0):
         self.x, self.y = gp.rotate_point(self.x, self.y, rotation, cx, cy)
 
+    def _scale(self, factor):
+        self.x *= factor
+        self.y *= factor
+
     def to_primitives(self, unit=None):
         conv = self.converted(unit)
         yield from self.aperture.flash(conv.x, conv.y, unit, self.polarity_dark)
@@ -246,62 +278,144 @@ class Region(GraphicObject):
      * A region is always exactly one connected component.
      * A region must not overlap itself anywhere.
      * A region cannot have holes.
+     * The last outline point of the region must be equal to the first.
 
     There is one exception from the last two rules: To emulate a region with a hole in it, *cut-ins* are allowed. At a
     cut-in, the region is allowed to touch (but never overlap!) itself.
 
-    :attr poly: :py:class:`~.graphic_primitives.ArcPoly` describing the actual outline of this Region. The coordinates of
-                this poly are in the unit of this instance's :py:attr:`unit` field.
+    When ``arc_centers`` is empty, this region has only straight outline segments. When ``arc_centers`` is not empty,
+    the i-th entry defines the i-th outline segment, with a ``None`` entry designating a straight line segment.
+    An arc is defined by a ``(clockwise, (cx, cy))`` tuple, where ``clockwise`` can be ``True`` for a clockwise arc, or
+    ``False`` for a counter-clockwise arc. ``cx`` and ``cy`` are the absolute coordinates of the arc's center. 
     """
 
-    def __init__(self, outline=None, arc_centers=None, *, unit, polarity_dark):
-        super().__init__(unit=unit, polarity_dark=polarity_dark)
-        outline = [] if outline is None else outline
-        arc_centers = [] if arc_centers is None else arc_centers
-        self.poly = gp.ArcPoly(outline, arc_centers)
+    def __init__(self, outline=None, arc_centers=None, *, unit=MM, polarity_dark=True):
+        self.unit = unit
+        self.polarity_dark = polarity_dark
+        self.outline = [] if outline is None else outline
+        self.arc_centers = [] if arc_centers is None else arc_centers
+        self.close()
 
     def __len__(self):
-        return len(self.poly)
+        return len(self.outline)
 
     def __bool__(self):
-        return bool(self.poly)
+        return bool(self.outline)
+
+    def __str__(self):
+        return f'<Region with {len(self.outline)} points and {sum(1 if c else 0 for c in self.arc_centers)} arc segments at {hex(id(self))}'
 
     def _offset(self, dx, dy):
-        self.poly.outline = [ (x+dx, y+dy) for x, y in self.poly.outline ]
+        self.outline = [ (x+dx, y+dy) for x, y in self.outline ]
+        self.arc_centers = [ (c[0], (c[1][0]+dx, c[1][1]+dy)) if c else None for c in self.arc_centers ]
 
     def _rotate(self, angle, cx=0, cy=0):
-        self.poly.outline = [ gp.rotate_point(x, y, angle, cx, cy) for x, y in self.poly.outline ]
-        self.poly.arc_centers = [
-                (arc[0], gp.rotate_point(*arc[1], angle, cx-p[0], cy-p[1])) if arc else None
-                for p, arc in zip(self.poly.outline, self.poly.arc_centers) ]
+        self.outline = [ gp.rotate_point(x, y, angle, cx, cy) for x, y in self.outline ]
+        self.arc_centers = [
+                (arc[0], gp.rotate_point(*arc[1], angle, cx, cy)) if arc else None
+                for arc in self.arc_centers ]
+
+    def _scale(self, factor):
+        self.outline = [ (x*factor, y*factor) for x, y in self.outline ]
+        self.arc_centers = [
+                (arc[0], (arc[1][0]*factor, arc[1][1]*factor)) if arc else None
+                for p, arc in zip_longest(self.outline, self.arc_centers) ]
+
+    def close(self):
+        if self.outline and self.outline[-1] != self.outline[0]:
+            self.outline.append(self.outline[0])
+            if self.arc_centers:
+                self.arc_centers.append((None, (None, None)))
+
+    @classmethod
+    def from_rectangle(kls, x, y, w, h, unit=MM):
+        return kls([
+            (x, y),
+            (x+w, y),
+            (x+w, y+h),
+            (x, y+h),
+            ], unit=unit)
+
+    @classmethod
+    def from_arc_poly(kls, arc_poly, polarity_dark=None, unit=MM):
+        polarity = arc_poly.polarity_dark if polarity_dark is None else polarity_dark
+        return kls(arc_poly.outline, arc_poly.arc_centers, polarity_dark=polarity, unit=unit)
 
     def append(self, obj):
         if obj.unit != self.unit:
             obj = obj.converted(self.unit)
 
-        if not self.poly.outline:
-            self.poly.outline.append(obj.p1)
-        self.poly.outline.append(obj.p2)
+        if not self.outline:
+            self.outline.append(obj.p1)
+        self.outline.append(obj.p2)
 
         if isinstance(obj, Arc):
-            self.poly.arc_centers.append((obj.clockwise, obj.center_relative))
+            self.arc_centers.append((obj.clockwise, obj.center))
         else:
-            self.poly.arc_centers.append(None)
+            self.arc_centers.append(None)
+
+    def iter_segments(self, tolerance=1e-6):
+        for points, arc in zip_longest(pairwise(self.outline), self.arc_centers):
+            if arc:
+                if points:
+                    yield *points, arc
+                else:
+                    yield self.outline[-1], self.outline[0], arc
+                    return
+            else:
+                if not points:
+                    break
+                yield *points, (None, (None, None))
+
+        # Close outline if necessary.
+        if math.dist(self.outline[0], self.outline[-1]) > tolerance:
+            yield self.outline[-1], self.outline[0], (None, (None, None))
+
+    def outline_objects(self, aperture=None):
+        for p1, p2, (clockwise, center) in self.iter_segments():
+            if clockwise is not None:
+                yield Arc(*p1, *p2, *center, clockwise, aperture=aperture, unit=self.unit, polarity_dark=self.polarity_dark)
+            else:
+                yield Line(*p1, *p2, aperture=aperture, unit=self.unit, polarity_dark=self.polarity_dark)
+
+    def _aperture_macro_primitives(self, max_error=1e-2, clip_max_error=True, unit=MM):
+        # unit is only for max_error, the resulting primitives will always be in MM
+        
+        if len(self.outline) < 2:
+            return
+
+        points = []
+        for p1, p2, (clockwise, center) in self.iter_segments():
+            if clockwise is not None:
+                for p in approximate_arc(*center, *p1, *p2, clockwise,
+                                             max_error=max_error, clip_max_error=clip_max_error):
+                    points.append(p)
+                    points.pop()
+            else:
+                points.append(p1)
+        points.append(p2)
+
+        if points[0] != points[-1]:
+            points.append(points[0])
+
+        yield amp.Outline(self.unit, int(self.polarity_dark), len(points)-1, tuple(coord for p in points for coord in p))
 
     def to_primitives(self, unit=None):
-        self.poly.polarity_dark = self.polarity_dark # FIXME: is this the right spot to do this?
         if unit == self.unit:
-            yield self.poly
+            yield gp.ArcPoly(outline=self.outline, arc_centers=self.arc_centers, polarity_dark=self.polarity_dark)
 
         else:
             to = lambda value: self.unit.convert_to(unit, value)
-            conv_outline = [ (to(x), to(y)) for x, y in self.poly.outline ]
+            conv_outline = [ (to(x), to(y)) for x, y in self.outline ]
             convert_entry = lambda entry: (entry[0], (to(entry[1][0]), to(entry[1][1])))
-            conv_arc = [ None if entry is None else convert_entry(entry) for entry in self.poly.arc_centers ]
+            conv_arc = [ None if entry is None else convert_entry(entry) for entry in self.arc_centers ]
 
             yield gp.ArcPoly(conv_outline, conv_arc, polarity_dark=self.polarity_dark)
 
     def to_statements(self, gs):
+        if len(self.outline) < 3:
+            return
+
         yield from gs.set_polarity(self.polarity_dark)
         yield 'G36*'
         # Repeat interpolation mode at start of region statement to work around gerbv bug. Without this, gerbv will
@@ -309,31 +423,26 @@ class Region(GraphicObject):
         # TODO report gerbv issue upstream
         yield gs.interpolation_mode_statement() + '*'
 
-        yield from gs.set_current_point(self.poly.outline[0], unit=self.unit)
+        yield from gs.set_current_point(self.outline[0], unit=self.unit)
 
-        for point, arc_center in zip(self.poly.outline[1:], self.poly.arc_centers):
-            if arc_center is None:
+        for previous_point, point, (clockwise, center) in self.iter_segments():
+            if point is None and center is None:
+                break
+
+            x = gs.file_settings.write_gerber_value(point[0], self.unit)
+            y = gs.file_settings.write_gerber_value(point[1], self.unit)
+
+            if clockwise is None:
                 yield from gs.set_interpolation_mode(InterpMode.LINEAR)
-
-                x = gs.file_settings.write_gerber_value(point[0], self.unit)
-                y = gs.file_settings.write_gerber_value(point[1], self.unit)
                 yield f'X{x}Y{y}D01*'
 
-                gs.update_point(*point, unit=self.unit)
-
             else:
-                clockwise, (cx, cy) = arc_center
-                x2, y2 = point
                 yield from gs.set_interpolation_mode(InterpMode.CIRCULAR_CW if clockwise else InterpMode.CIRCULAR_CCW)
-
-                x = gs.file_settings.write_gerber_value(x2, self.unit)
-                y = gs.file_settings.write_gerber_value(y2, self.unit)
-                # TODO are these coordinates absolute or relative now?!
-                i = gs.file_settings.write_gerber_value(cx, self.unit)
-                j = gs.file_settings.write_gerber_value(cy, self.unit)
+                i = gs.file_settings.write_gerber_value(center[0]-previous_point[0], self.unit)
+                j = gs.file_settings.write_gerber_value(center[1]-previous_point[1], self.unit)
                 yield f'X{x}Y{y}I{i}J{j}D01*'
 
-                gs.update_point(x2, y2, unit=self.unit)
+            gs.update_point(*point, unit=self.unit)
 
         yield 'G37*'
 
@@ -374,6 +483,12 @@ class Line(GraphicObject):
         self.x1, self.y1 = gp.rotate_point(self.x1, self.y1, rotation, cx, cy)
         self.x2, self.y2 = gp.rotate_point(self.x2, self.y2, rotation, cx, cy)
 
+    def _scale(self, factor):
+        self.x1 *= factor
+        self.y1 *= factor
+        self.x2 *= factor
+        self.y2 *= factor
+
     @property
     def p1(self):
         """ Convenience alias for ``(self.x1, self.y1)`` returning start point of the line. """
@@ -400,10 +515,20 @@ class Line(GraphicObject):
         """
         return self.tool.plated
 
-    def to_primitives(self, unit=None):
+    def as_primitive(self, unit=None):
         conv = self.converted(unit)
         w = self.aperture.equivalent_width(unit) if self.aperture else 0.1 # for debugging
-        yield gp.Line(*conv.p1, *conv.p2, w, polarity_dark=self.polarity_dark)
+        return gp.Line(*conv.p1, *conv.p2, w, polarity_dark=self.polarity_dark)
+
+    def to_primitives(self, unit=None):
+        yield self.as_primitive(unit=unit)
+
+    def _aperture_macro_primitives(self):
+        obj = self.converted(MM) # Gerbonara aperture macros use MM units.
+        width = obj.aperture.equivalent_width(MM)
+        yield amp.VectorLine(MM, int(self.polarity_dark), width, obj.x1, obj.y1, obj.x2, obj.y2, 0)
+        yield amp.Circle(MM, int(self.polarity_dark), width, obj.x1, obj.y1)
+        yield amp.Circle(MM, int(self.polarity_dark), width, obj.x2, obj.y2)
 
     def to_statements(self, gs):
         yield from gs.set_polarity(self.polarity_dark)
@@ -463,6 +588,10 @@ class Arc(GraphicObject):
     #: Aperture for this arc. Should be a subclass of :py:class:`.CircleAperture`, whose diameter determines the line
     #: width.
     aperture : object
+
+    @classmethod
+    def from_circle(kls, cx, cy, r, aperture, unit=MM):
+        return kls(cx-r, cy, cx-r, cy, r, 0, aperture=aperture, clockwise=True, unit=MM)
     
     def _offset(self, dx, dy):
         self.x1 += dx
@@ -495,22 +624,8 @@ class Arc(GraphicObject):
         :returns: Angle in clockwise radian between ``0`` and ``2*math.pi``
         :rtype: float
         """
-        cx, cy = self.cx + self.x1, self.cy + self.y1
-        x1, y1 = self.x1 - cx, self.y1 - cy
-        x2, y2 = self.x2 - cx, self.y2 - cy
 
-        a1, a2 = math.atan2(y1, x1), math.atan2(y2, x2)
-        f = abs(a2 - a1)
-        if not self.clockwise:
-            if a2 > a1:
-                return a2 - a1
-            else:
-                return 2*math.pi - abs(a2 - a1)
-        else:
-            if a1 > a2:
-                return a1 - a2
-            else:
-                return 2*math.pi - abs(a1 - a2)
+        return sweep_angle(self.cx+self.x1, self.cy+self.y1, self.x1, self.y1, self.x2, self.y2, self.clockwise)
 
     @property
     def p1(self):
@@ -567,34 +682,16 @@ class Arc(GraphicObject):
         :returns: list of :py:class:`~.graphic_objects.Line` instances.
         :rtype: list
         """
-        # TODO the max_angle calculation below is a bit off -- we over-estimate the error, and thus produce finer
-        # results than necessary. Fix this.
-            
-        r = math.hypot(self.cx, self.cy)
 
         max_error = self.unit(max_error, unit)
-        if clip_max_error:
-            # 1 - math.sqrt(1 - 0.5*math.sqrt(2))
-            max_error = min(max_error, r*0.4588038998538031)
-
-        elif max_error >= r:
-            return [Line(*self.p1, *self.p2, aperture=self.aperture, polarity_dark=self.polarity_dark)]
-
-        # see https://www.mathopenref.com/sagitta.html
-        l = math.sqrt(r**2 - (r - max_error)**2)
-
-        angle_max = math.asin(l/r)
-        sweep_angle = self.sweep_angle()
-        num_segments = math.ceil(sweep_angle / angle_max)
-        angle = sweep_angle / num_segments
-
-        if not self.clockwise:
-            angle = -angle
-
-        cx, cy = self.center
-        points = [ rotate_point(self.x1, self.y1, i*angle, cx, cy) for i in range(num_segments + 1) ]
-        return [ Line(*p1, *p2, aperture=self.aperture, polarity_dark=self.polarity_dark)
-                for p1, p2 in zip(points[0::], points[1::]) ]
+        return [Line(*p1, *p2, aperture=self.aperture, polarity_dark=self.polarity_dark, unit=self.unit)
+                for p1, p2 in pairwise(approximate_arc(
+                    self.cx+self.x1, self.cy+self.y1,
+                    self.x1, self.y1,
+                    self.x2, self.y2,
+                    self.clockwise,
+                    max_error=max_error,
+                    clip_max_error=clip_max_error))]
 
     def _rotate(self, rotation, cx=0, cy=0):
         # rotate center first since we need old x1, y1 here
@@ -603,16 +700,38 @@ class Arc(GraphicObject):
         self.x2, self.y2 = gp.rotate_point(self.x2, self.y2, rotation, cx, cy)
         self.cx, self.cy = new_cx - self.x1, new_cy - self.y1
 
-    def to_primitives(self, unit=None):
+    def _scale(self, factor):
+        self.x1 *= factor
+        self.y1 *= factor
+        self.x2 *= factor
+        self.y2 *= factor
+        self.cx *= factor
+        self.cy *= factor
+
+    def as_primitive(self, unit=None):
         conv = self.converted(unit)
-        w = self.aperture.equivalent_width(unit) if self.aperture else 0.1 # for debugging
-        yield gp.Arc(x1=conv.x1, y1=conv.y1,
+        w = self.aperture.equivalent_width(unit) if self.aperture else 0
+        return gp.Arc(x1=conv.x1, y1=conv.y1,
                 x2=conv.x2, y2=conv.y2,
-                cx=conv.cx, cy=conv.cy,
+                cx=conv.cx+conv.x1, cy=conv.cy+conv.y1,
                 clockwise=self.clockwise,
                 width=w,
                 polarity_dark=self.polarity_dark)
 
+    def to_primitives(self, unit=None):
+        yield self.as_primitive(unit=unit)
+
+    def to_region(self):
+        reg = Region(unit=self.unit, polarity_dark=self.polarity_dark)
+        reg.append(self)
+        reg.close()
+        return reg
+
+    def _aperture_macro_primitives(self, max_error=1e-2, unit=MM):
+        # unit is only for max_error, the resulting primitives will always be in MM
+        for line in self.approximate(max_error=max_error, unit=unit):
+            yield from line._aperture_macro_primitives()
+
     def to_statements(self, gs):
         yield from gs.set_polarity(self.polarity_dark)
         yield from gs.set_aperture(self.aperture)

src/gerbonara/graphic_primitives.py

@@ -0,0 +1,379 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import math
+import itertools
+
+from dataclasses import dataclass, replace, field
+
+from .utils import *
+
+prec = lambda x: f'{float(x):.6}'
+
+
+@dataclass(frozen=True)
+class GraphicPrimitive:
+
+    # hackety hack: Work around python < 3.10 not having dataclasses.KW_ONLY.
+    # 
+    # For details, refer to graphic_objects.py
+    def __init_subclass__(cls):
+        cls.polarity_dark = True
+
+        d = {'polarity_dark': bool}
+        if hasattr(cls, '__annotations__'):
+            cls.__annotations__.update(d)
+        else:
+            cls.__annotations__ = d
+
+    def bounding_box(self):
+        """ Return the axis-aligned bounding box of this feature.
+
+        :returns: ``((min_x, min_Y), (max_x, max_y))``
+        :rtype: tuple
+        """
+
+        raise NotImplementedError()
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        """ Render this primitive into its SVG representation.
+
+        :param str fg: Foreground color. Must be an SVG color name.
+        :param str bg: Background color. Must be an SVG color name.
+        :param function tag: Tag constructor to use.
+
+        :rtype: str
+        """
+
+        raise NotImplementedError()
+
+    def is_zero_size(self):
+        """ Return whether this primitive is zero size
+
+        :rtype: bool
+        """
+
+
+@dataclass(frozen=True)
+class Circle(GraphicPrimitive):
+    #: Center X coordinate
+    x : float
+    #: Center y coordinate
+    y : float
+    #: Radius, not diameter like in :py:class:`.apertures.CircleAperture`
+    r : float # Here, we use radius as common in modern computer graphics, not diameter as gerber uses.
+
+    def bounding_box(self):
+        return ((self.x-self.r, self.y-self.r), (self.x+self.r, self.y+self.r))
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        color = fg if self.polarity_dark else bg
+        return tag('circle', cx=prec(self.x), cy=prec(self.y), r=prec(self.r), fill=color)
+
+    def to_arc_poly(self):
+        return ArcPoly([(self.x-self.r, self.y), (self.x+self.r, self.y)],
+                       [(True, (self.x, self.y)), (True, (self.x, self.y))],
+                       polarity_dark=self.polarity_dark)
+
+    def is_zero_size(self):
+        return math.isclose(self.r, 0)
+
+
+@dataclass(frozen=True)
+class ArcPoly(GraphicPrimitive):
+    """ Polygon whose sides may be either straight lines or circular arcs. """
+
+    #: list of (x : float, y : float) tuples. Describes closed outline, i.e. the first and last point are considered
+    #: connected.
+    outline : list
+    #: Must be either None (all segments are straight lines) or same length as outline.
+    #: Straight line segments have None entry. Arc segments have (clockwise, (cx, cy)) tuple with cx, cy being absolute
+    #: coords.
+    arc_centers : list = field(default_factory=list)
+
+    @property
+    def segments(self):
+        """ Return an iterator through all *segments* of this polygon. For each outline segment (line or arc), this
+        iterator will yield a ``(p1, p2, (clockwise, center))`` tuple. If the segment is a straight line, ``clockwise``
+        will be ``None``.
+        """
+        for points, arc in itertools.zip_longest(itertools.pairwise(self.outline), self.arc_centers):
+            if arc:
+                if points:
+                    yield *points, arc
+                else:
+                    yield self.outline[-1], self.outline[0], arc
+                    return
+            else:
+                if not points:
+                    break
+                yield *points, (None, (None, None))
+
+        # Close outline if necessary.
+        if math.dist(self.outline[0], self.outline[-1]) > 1e-6:
+            yield self.outline[-1], self.outline[0], (None, (None, None))
+
+    def approximate_arcs(self, max_error=1e-2, clip_max_error=True):
+        outline = []
+        for (x1, y1), (x2, y2), (clockwise, (cx, cy)) in self.segments:
+            if clockwise is None:
+                outline.append((x1, y1))
+            else:
+                outline.extend(approximate_arc(cx, cy, x1, y1, x2, y2, clockwise,
+                                               max_error=max_error, clip_max_error=clip_max_error))
+                outline.pop() # remove arc end point
+        return type(self)(outline, polarity_dark=self.polarity_dark)
+
+    def bounding_box(self):
+        bbox = (None, None), (None, None)
+        for (x1, y1), (x2, y2), (clockwise, (cx, cy)) in self.segments:
+            if clockwise is None:
+                line_bounds = (min(x1, x2), min(y1, y2)), (max(x1, x2), max(y1, y2))
+                bbox = add_bounds(bbox, line_bounds)
+            else:
+                bbox = add_bounds(bbox, arc_bounds(x1, y1, x2, y2, cx, cy, clockwise))
+        return bbox
+
+    @classmethod
+    def from_regular_polygon(kls, x:float, y:float, r:float, n:int, rotation:float=0, polarity_dark:bool=True):
+        """ Convert an n-sided gerber polygon to a normal ArcPoly defined by outline """
+
+        delta = 2*math.pi / n
+
+        return kls([
+                (x + math.cos(rotation + i*delta) * r,
+                 y + math.sin(rotation + i*delta) * r)
+                for i in range(n) ], polarity_dark=polarity_dark)
+
+    def __len__(self):
+        """ Return the number of points on this polygon's outline (which is also the number of segments because the
+        polygon is closed). """
+        return len(self.outline)
+
+    def __bool__(self):
+        """ Return ``True`` if this polygon has any outline points. """
+        return bool(len(self))
+
+    def path_d(self):
+        if len(self.outline) == 0:
+            return
+
+        yield f'M {float(self.outline[0][0]):.6} {float(self.outline[0][1]):.6}'
+
+        for old, new, (clockwise, center) in self.segments:
+            if clockwise is None:
+                yield f'L {float(new[0]):.6} {float(new[1]):.6}'
+            else:
+                yield svg_arc(old, new, center, clockwise)
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        color = fg if self.polarity_dark else bg
+        return tag('path', d=' '.join(self.path_d()), fill=color)
+
+    def to_arc_poly(self):
+        return self
+
+
+    def is_zero_size(self):
+        for (x1, y1), (x2, y2), (clockwise, (cx, cy)) in self.segments:
+            if clockwise is not None: # arc
+                if math.isclose(cx, x1) and math.isclose(cy, y1):
+                    continue
+                
+                if math.isclose(x1, x2) and math.isclose(y1, y2):
+                    return False
+
+        if math.isclose(polygon_area(self.outline), 0):
+            return True
+        return False
+
+
+@dataclass(frozen=True)
+class Line(GraphicPrimitive):
+    """ Straight line with round end caps. """
+    #: Start X coordinate. As usual in modern graphics APIs, this is at the center of the half-circle capping off this
+    #: line.
+    x1 : float
+    #: Start Y coordinate
+    y1 : float
+    #: End X coordinate
+    x2 : float
+    #: End Y coordinate
+    y2 : float
+    #: Line width
+    width : float
+
+    def flip(self):
+        return replace(self, x1=self.x2, y1=self.y2, x2=self.x1, y2=self.y1)
+
+    @classmethod
+    def from_obround(kls, x:float, y:float, w:float, h:float, rotation:float=0, polarity_dark:bool=True):
+        """ Convert a gerber obround into a :py:class:`~.graphic_primitives.Line`. """
+        if w > h:
+            w, a, b = h, w-h, 0
+        else:
+            w, a, b = w, 0, h-w
+
+        return kls(
+                *rotate_point(x-a/2, y-b/2, rotation, x, y),
+                *rotate_point(x+a/2, y+b/2, rotation, x, y),
+                w, polarity_dark=polarity_dark)
+
+    def bounding_box(self):
+        r = self.width / 2
+        return add_bounds(Circle(self.x1, self.y1, r).bounding_box(), Circle(self.x2, self.y2, r).bounding_box())
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        color = fg if self.polarity_dark else bg
+        width = f'{self.width:.6}' if not math.isclose(self.width, 0) else '0.01mm'
+        return tag('path', d=f'M {float(self.x1):.6} {float(self.y1):.6} L {float(self.x2):.6} {float(self.y2):.6}',
+                fill='none', stroke=color, stroke_width=str(width), stroke_linecap='round')
+
+    def to_arc_poly(self):
+        l = math.dist((self.x1, self.y1), (self.x2, self.y2))
+        if math.isclose(l, 0):
+            # degenerate case: a zero-length line becomes a circle.
+            return ArcPoly([(self.x1-self.width/2, self.y1), (self.x1+self.width/2, self.y1)],
+                           [(True, (self.x1, self.y1)), (True, (self.x1, self.y1))],
+                           polarity_dark=self.polarity_dark)
+
+        dx, dy = self.x2-self.x1, self.y2-self.y1
+        nx, ny = -dy/l, dx/l
+        rx, ry = nx*self.width/2, ny*self.width/2
+        return ArcPoly([
+                    (self.x2+rx, self.y2+ry),
+                    (self.x2-rx, self.y2-ry),
+                    (self.x1-rx, self.y1-ry),
+                    (self.x1+rx, self.y1+ry),
+                ], [
+                    (True, (self.x2, self.y2)),
+                    None,
+                    (True, (self.x1, self.y1)),
+                    None,
+                ], polarity_dark=self.polarity_dark)
+
+    def is_zero_size(self):
+        return math.isclose(self.x1, self.x2) and math.isclose(self.y1, self.y2)
+
+
+@dataclass(frozen=True)
+class Arc(GraphicPrimitive):
+    """ Circular arc with line width ``width`` going from ``(x1, y1)`` to ``(x2, y2)`` around center at ``(cx, cy)``. """
+    #: Start X coodinate
+    x1 : float
+    #: Start Y coodinate
+    y1 : float
+    #: End X coodinate
+    x2 : float
+    #: End Y coodinate
+    y2 : float
+    #: Center X coordinate (absolute)
+    cx : float
+    #: Center Y coordinate (absolute)
+    cy : float
+    #: ``True`` if this arc is clockwise from start to end. Selects between the large arc and the small arc given this
+    #: start, end and center
+    clockwise : bool
+    #: Line width of this arc.
+    width : float
+
+    @property
+    def is_circle(self):
+        return math.isclose(self.x1, self.x2, abs_tol=1e-6) and math.isclose(self.y1, self.y2, abs_tol=1e-6)
+
+    def flip(self):
+        return replace(self, x1=self.x2, y1=self.y2, x2=self.x1, y2=self.y1, clockwise=not self.clockwise)
+
+    def bounding_box(self):
+        r = self.width/2
+        (min_x, min_y), (max_x, max_y) = arc_bounds(self.x1, self.y1, self.x2, self.y2, self.cx, self.cy, self.clockwise)
+        return (min_x-r, min_y-r), (max_x+r, max_y+r)
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        color = fg if self.polarity_dark else bg
+        arc = svg_arc((self.x1, self.y1), (self.x2, self.y2), (self.cx, self.cy), self.clockwise)
+        width = f'{self.width:.6}' if not math.isclose(self.width, 0) else '0.01mm'
+        return tag('path', d=f'M {float(self.x1):.6} {float(self.y1):.6} {arc}',
+                fill='none', stroke=color, stroke_width=width, stroke_linecap='round')
+
+    def to_arc_poly(self):
+        r = math.dist((self.x1, self.y1), (self.cx, self.cy))
+
+        if math.isclose(r, 0):
+            # degenerate case: a zero-radius arc becomes a circle.
+            return ArcPoly([(self.x1-self.width/2, self.y1), (self.x1+self.width/2, self.y1)],
+                           [(True, (self.x1, self.y1)), (True, (self.x1, self.y1))],
+                           polarity_dark=self.polarity_dark)
+
+        dx1, dy1 = self.x1-self.cx, self.y1-self.cy
+        nx1, ny1 = dx1/r * self.width/2, dy1/r * self.width/2
+        dx2, dy2 = self.x2-self.cx, self.y2-self.cy
+        nx2, ny2 = dx2/r * self.width/2, dy2/r * self.width/2
+        return ArcPoly([ # vertices
+                    (self.x1+nx1, self.y1+ny1),
+                    (self.x1-nx1, self.y1-ny1),
+                    (self.x2-nx2, self.y2-ny2),
+                    (self.x2+nx2, self.y2+ny2),
+                ], [ # arc segments (direction, center)
+                    (not self.clockwise, (self.x1, self.y1)),
+                    (self.clockwise, (self.cx, self.cy)),
+                    (self.clockwise, (self.x2, self.y2)),
+                    (not self.clockwise, (self.cx, self.cy)),
+                ], polarity_dark=self.polarity_dark)
+
+    def is_zero_size(self):
+        return False # an arc with identical start and end points is defined as a circle
+
+
+@dataclass(frozen=True)
+class Rectangle(GraphicPrimitive):
+    #: **Center** X coordinate
+    x : float
+    #: **Center** Y coordinate
+    y : float
+    #: width
+    w : float
+    #: height
+    h : float
+    #: rotation around center in radians
+    rotation : float
+
+    def bounding_box(self):
+        return self.to_arc_poly().bounding_box()
+
+    def to_arc_poly(self):
+        sin, cos = math.sin(self.rotation), math.cos(self.rotation)
+        sw, cw = sin*self.w/2, cos*self.w/2
+        sh, ch = sin*self.h/2, cos*self.h/2
+        x, y = self.x, self.y
+        return ArcPoly([
+            (x - (cw+sh), y - (ch+sw)),
+            (x - (cw+sh), y + (ch+sw)),
+            (x + (cw+sh), y + (ch+sw)),
+            (x + (cw+sh), y - (ch+sw)),
+            ], polarity_dark=self.polarity_dark)
+
+    def to_svg(self, fg='black', bg='white', tag=Tag):
+        color = fg if self.polarity_dark else bg
+        x, y = self.x - self.w/2, self.y - self.h/2
+        return tag('rect', x=prec(x), y=prec(y), width=prec(self.w), height=prec(self.h),
+                **svg_rotation(self.rotation, self.x, self.y), fill=color)
+
+    def is_zero_size(self):
+        return math.isclose(self.w, 0) or math.isclose(self.h, 0)
+

src/gerbonara/ipc356.py

@@ -3,7 +3,7 @@
 #
 # copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
 # Modified from parser.py by Paulo Henrique Silva <ph.silva@gmail.com>
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@ import math
 import re
 from enum import Enum
 import warnings
-from dataclasses import dataclass, KW_ONLY
+from dataclasses import dataclass
 from pathlib import Path
 
 from .cam import CamFile, FileSettings
@@ -120,15 +120,15 @@ class Netlist(CamFile):
         return parser.parse(data, Path(filename))
 
     def save(self, filename, settings=None, drop_comments=True):
-        with open(filename, 'w', encoding='utf-8') as f:
-            f.write(self.to_ipc356(settings, drop_comments=drop_comments))
+        with open(filename, 'wb') as f:
+            f.write(self.write_to_bytes(settings, drop_comments=drop_comments))
 
-    def to_ipc356(self, settings=None, drop_comments=True, job_name=None):
+    def write_to_bytes(self, settings=None, drop_comments=True, job_name=None):
         if settings is None:
             settings = self.import_settings.copy() or FileSettings()
             settings.zeros = None
             settings.number_format = (5,6)
-        return '\n'.join(self._generate_lines(settings, drop_comments=drop_comments))
+        return '\n'.join(self._generate_lines(settings, drop_comments=drop_comments)).encode('utf-8')
 
     def _generate_lines(self, settings, drop_comments, job_name=None):
         yield 'C  IPC-D-356 generated by Gerbonara'
@@ -326,17 +326,17 @@ class NetlistParser(object):
 
             if name == 'UNITS':
                 if value in ('CUST', 'CUST 0'):
-                    self.settings.units = Inch
+                    self.settings.unit = Inch
                     self.settings.angle_unit = 'degree'
                     self.has_unit = True
 
                 elif value == 'CUST 1':
-                    self.settings.units = MM
+                    self.settings.unit = MM
                     self.settings.angle_unit = 'degree'
                     self.has_unit = True
 
                 elif value == 'CUST 2':
-                    self.settings.units = Inch
+                    self.settings.unit = Inch
                     self.settings.angle_unit = 'radian'
                     self.has_unit = True
 
@@ -414,7 +414,6 @@ class TestRecord:
     rotation : float = 0
     solder_mask : SoldermaskInfo = None
     lefover : str = None
-    _ : KW_ONLY
     unit : LengthUnit = None
 
     def __str__(self):
@@ -563,7 +562,6 @@ def format_coord_chain(line, settings, coords, cont, unit):
 class Outline:
     outline_type : OutlineType
     outline : [(float,)]
-    _ : KW_ONLY
     unit : LengthUnit = None
 
     @classmethod
@@ -596,7 +594,6 @@ class Conductor:
     layer : int
     aperture : (float,)
     coords : [(float,)]
-    _ : KW_ONLY
     unit : LengthUnit = None
 
     @classmethod

src/gerbonara/layer_rules.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -39,15 +39,17 @@ MATCH_RULES = {
 'kicad': {
     'top copper':       r'.*\.gtl|.*f.cu.(gbr|gtl)',
     'top mask':         r'.*\.gts|.*f.mask.(gbr|gts)',
-    'top silk':         r'.*\.gto|.*f.silks.(gbr|gto)',
+    'top silk':         r'.*\.gto|.*f.silks(creen)?.(gbr|gto)',
     'top paste':        r'.*\.gtp|.*f.paste.(gbr|gtp)',
     'bottom copper':    r'.*\.gbl|.*b.cu.(gbr|gbl)',
     'bottom mask':      r'.*\.gbs|.*b.mask.(gbr|gbs)',
-    'bottom silk':      r'.*\.gbo|.*b.silks.(gbr|gbo)',
+    'bottom silk':      r'.*\.gbo|.*b.silks(creen)?.(gbr|gbo)',
     'bottom paste':     r'.*\.gbp|.*b.paste.(gbr|gbp)',
     'inner copper':     r'.*\.gp?([0-9]+)|.*inn?e?r?([0-9]+).cu.(?:gbr|g[0-9]+)',
     'mechanical outline':    r'.*\.(gm[0-9]+)|.*edge.cuts.(gbr|gm1)',
-    'drill plated':     r'.*\.(drl)',
+    'drill nonplated':  r'.*\-NPTH.(drl)',
+    'drill plated':     r'.*\-PTH.(drl)',
+    'drill unknown':    r'.*\.(drl)',
     'other netlist':    r'.*\.d356',
     },
 
@@ -80,6 +82,7 @@ MATCH_RULES = {
     'bottom paste':     r'.*_boardoutline\.\w+', # FIXME verify this
     'drill plated':     r'.*\.(drl)', # diptrace has unplated drills on the outline layer
     'other netlist':    r'.*\.ipc', # default rule due to lack of tool-specific examples
+    'header regex':     [['sufficient', r'top .*|bottom .*', r'G04 DipTrace [.-0-9a-z]*\*']],
     },
 
 'target': {
@@ -149,22 +152,25 @@ MATCH_RULES = {
 
 'allegro': {
     # Allegro doesn't have any widespread convention, so we rely heavily on the layer name auto-guesser here.
-    'drill mech': r'.*\.(drl|rou)',
-    'generic gerber': r'.*\.art',
+    'drill plated':     r'.*\.(drl)',
+    'drill nonplated':  r'.*\.(rou)',
+    'other unknown':    r'.*(place|assembly|keep.?in|keep.?out).*\.art',
+    'autoguess':        r'.*\.art',
     'excellon params':  r'nc_param\.txt|ncdrill\.log|ncroute\.log',
     'other netlist':    r'.*\.ipc', # default rule due to lack of tool-specific examples
+    'header regex':     [['required,sufficient', r'.*\.art', r'G04 File Origin:\s+Cadence Allegro [0-9]+\.[0-9]+[-a-zA-Z0-9]*']],
     },
 
 'pads': {
     # Pads also does not seem to have a factory-default naming schema. Or it has one but everyone ignores it.
-    'generic gerber':   r'.*\.pho',
-    'drill mech':       r'.*\.drl',
+    'autoguess':        r'.*\.pho',
+    'drill plated':     r'.*\.drl',
     },
 
 'zuken': {
-    'generic gerber': r'.*\.fph',
+    'autoguess': r'.*\.fph',
     'gerber params': r'.*\.fpl',
-    'drill mech': r'.*\.fdr',
+    'drill unknown': r'.*\.fdr',
     'excellon params': r'.*\.fdl',
     'other netlist': r'.*\.ipc',
     'ipc-2581': r'.*\.xml',

src/gerbonara/newstroke.py

@@ -0,0 +1,167 @@
+#!/usr/bin/env python
+
+from pathlib import Path
+import unicodedata
+import re
+import ast
+from functools import lru_cache
+import math
+from importlib.resources import files
+
+from . import data
+from .utils import rotate_point, Tag
+
+
+STROKE_FONT_SCALE = 1/21
+FONT_OFFSET = -10
+DEFAULT_SPACE_WIDTH = 0.6
+DEFAULT_CHAR_GAP = 0.2
+
+_dec = lambda c: ord(c)-ord('R') 
+
+
+class Newstroke:
+    def __init__(self, newstroke_cpp=None):
+        if newstroke_cpp is None:
+            newstroke_cpp = files(data).joinpath('newstroke_font.cpp').read_bytes()
+        self.glyphs = dict(self.load_font(newstroke_cpp))
+
+    @classmethod
+    @lru_cache
+    def load(kls):
+        return kls()
+
+    def render(self, text, size=1.0, x0=0, y0=0, rotation=0, h_align='left', v_align='bottom', space_width=DEFAULT_SPACE_WIDTH, char_gap=DEFAULT_CHAR_GAP, scale=(1, 1), mirror=(False, False)):
+        text = unicodedata.normalize('NFC', text)
+        missing_glyph = self.glyphs['?']
+        sx, sy = scale
+        mx, my = mirror
+        x = 0
+
+        if rotation >= 180:
+            rotation -= 180
+            h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+            x0, y0 = -x0, y0
+
+#        if mx:
+#            y0 = -y0
+#            if rotation == 0:
+#                v_align = {'top': 'bottom', 'bottom': 'top'}.get(v_align, v_align)
+#            else:
+#                h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+
+        x0, y0 = rotate_point(x0, y0, math.radians(-rotation))
+
+        alx, aly = 0, 0
+        (minx, miny), (maxx, maxy) = bbox = self.bounding_box(text, size, space_width, char_gap)
+        w = maxx - minx
+
+        if my:
+            if rotation == 0:
+                sx = -1
+                h_align = {'left': 'right', 'right': 'left'}.get(h_align, h_align)
+            else:
+                sy = -sy
+
+        if h_align != 'left':
+            if h_align == 'right':
+                alx = -w
+            elif h_align == 'center':
+                alx = -w/2
+            else:
+                raise ValueError(f'Invalid h_align value "{h_align}"')
+
+        if v_align == 'top':
+            aly = sy*1.2*size
+        elif v_align == 'middle':
+            aly = sy*1.2*size/2
+        elif v_align != 'bottom':
+                raise ValueError(f'Invalid v_align value "{v_align}"')
+
+        for c in text:
+            if c == ' ':
+                x += space_width
+                continue
+
+            width, strokes = self.glyphs.get(c, missing_glyph)
+            glyph_w = max(width, max(x for st in strokes for x, _y in st))
+
+            for st in strokes:
+                yield [rotate_point((px+x)*sx*size+alx+x0, py*sy*size+aly+y0, math.radians(-rotation), x0, y0) for px, py in st]
+
+            x += glyph_w
+
+    def render_svg(self, text, size=1.0, x0=0, y0=0, rotation=0, h_align='left', v_align='bottom', space_width=DEFAULT_SPACE_WIDTH, char_gap=DEFAULT_CHAR_GAP, scale=(1, -1), mirror=(False, False), **svg_attrs):
+        if 'stroke_linecap' not in svg_attrs:
+            svg_attrs['stroke_linecap'] = 'round'
+        if 'stroke_linejoin' not in svg_attrs:
+            svg_attrs['stroke_linejoin'] = 'round'
+        if 'stroke_width' not in svg_attrs:
+            svg_attrs['stroke_width'] = f'{0.2*size:.3f}'
+        svg_attrs['fill'] = 'none'
+
+        strokes = ['M ' + ' L '.join(f'{x:.3f} {y:.3f}' for x, y in stroke)
+                   for stroke in self.render(text, size=size, x0=x0, y0=y0, rotation=rotation, h_align=h_align,
+                                             v_align=v_align, mirror=mirror, space_width=space_width, char_gap=char_gap,
+                                             scale=scale)]
+        return Tag('path', d=' '.join(strokes), **svg_attrs)
+
+    def bounding_box(self, text, size=1.0, space_width=DEFAULT_SPACE_WIDTH, char_gap=DEFAULT_CHAR_GAP):
+        text = unicodedata.normalize('NFC', text)
+        missing_glyph = self.glyphs['?']
+        x = 0
+        for c in text:
+            if c == ' ':
+                x += space_width*size
+                continue
+
+            width, strokes = self.glyphs.get(c, missing_glyph)
+            glyph_w = max(width, max(x for st in strokes for x, _y in st))
+            x += glyph_w*size
+
+        return (0, -0.2*size), (x, 1.2*size)
+
+    def load_font(self, newstroke_cpp):
+        e = []
+        for char, (width, strokes) in self.load_glyphs(newstroke_cpp):
+            yield char, (width, strokes)
+
+    @classmethod
+    def decode_stroke(kls, stroke, start_x):
+        for i in range(0, len(stroke), 2):
+            x = (stroke[i]-0x52-start_x)*STROKE_FONT_SCALE
+            y = (stroke[i+1]-0x52+FONT_OFFSET)*STROKE_FONT_SCALE
+            yield (x, y)
+
+    @classmethod
+    def decode_glyph(kls, data):
+        start_x, end_x = data[0]-0x52, data[1]-0x52
+        width = end_x - start_x
+
+        strokes = tuple(tuple(kls.decode_stroke(st, start_x)) for st in data[2:].split(b' R'))
+        return width*STROKE_FONT_SCALE, strokes
+
+    @classmethod
+    def load_glyphs(kls, newstroke_cpp):
+        it = iter(newstroke_cpp.splitlines())
+        
+        for line in it:
+            if re.search(rb'char.*\*', line):
+                break
+
+        charcode = 0x20
+        for line in it:
+            if (match := re.search(rb'".*"', line)):
+                yield chr(charcode), kls.decode_glyph(match.group(0)[1:-1].replace(b'\\\\', b'\\'))
+                charcode += 1
+            else:
+                if b'}' in line:
+                    break
+
+
+if __name__ == '__main__':
+    import time
+    t1 = time.time()
+    Newstroke()
+    t2 = time.time()
+    print((t2-t1)*1000)

src/gerbonara/rs274x.py

@@ -4,7 +4,7 @@
 # Modified from parser.py by Paulo Henrique Silva <ph.silva@gmail.com>
 # Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
 # Copyright 2019 Hiroshi Murayama <opiopan@gmail.com>
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -21,9 +21,11 @@
 
 import re
 import math
+import copy
 import warnings
 from pathlib import Path
 import dataclasses
+import functools
 
 from .cam import CamFile, FileSettings
 from .utils import MM, Inch, units, InterpMode, UnknownStatementWarning
@@ -46,6 +48,19 @@ def points_close(a, b):
 
 class GerberFile(CamFile):
     """ A single gerber file.
+
+    :ivar objects: List of objects in this Gerber file. All elements must be subclasses of :py:class:`.GraphicObject`.
+    :ivar comments: List of string with textual comments in the source Gerber file. These are not saved by default, but
+                    when you call :py:meth:`.GerberFile.save` with ``drop_comments=False``, the contents of this list
+                    will be included as comments at the top of the output file.
+    :ivar generator_hints: List of strings indicating which EDA tool generated this file. Hints are added to this list
+                           during file parsing whenever the parser encounters an idiosyncratic file format variation.
+    :ivar import_settings: File format settings used in the original file. This can be empty if this
+                           :py:class:`.GerberFile` was generated programatically. 
+    :ivar layer_hints: Similar to ``generator_hints``, this is a list containing hints which layer type this file could
+                       belong to. Usually, this will be empty, but some EDA tools automatically include layer
+                       information inside tool-specific comments in the Gerber files they generate.
+    :ivar file_attrs: List of strings with Gerber X3 file attributes. Each list item corresponds to one file attribute.
     """
 
     def __init__(self, objects=None, comments=None, import_settings=None, original_path=None, generator_hints=None,
@@ -56,101 +71,169 @@ class GerberFile(CamFile):
         self.generator_hints = generator_hints or []
         self.layer_hints = layer_hints or []
         self.import_settings = import_settings
-        self.apertures = [] # FIXME get rid of this? apertures are already in the objects.
         self.file_attrs = file_attrs or {}
 
-    def to_excellon(self):
+    def apertures(self):
+        """ Iterate through all apertures in this layer. """
+        found = set()
+        for obj in self.objects:
+            if hasattr(obj, 'aperture'):
+                ap = obj.aperture
+                if ap not in found:
+                    found.add(ap)
+                    yield ap
+
+    def aperture_macros(self):
+        found = set()
+        for aperture in self.apertures():
+            if isinstance(aperture, apertures.ApertureMacroInstance):
+                macro = aperture.macro
+                if (macro.name, macro) not in found:
+                    found.add((macro.name, macro))
+                    yield macro
+
+    def map_apertures(self, map_or_callable, cache=True):
+        """ Replace all apertures in all objects in this layer according to the given map or callable.
+
+        When a map is passed, apertures that are not in the map are left alone. When a callable is given, it is called
+        with the old aperture as its argument.
+
+        :param map_or_callable: A dict-like object, or a callable mapping old to new apertures
+        :param cache: When True (default) and a callable is passed, caches the output of callable, only calling it once
+            for each old aperture.
+        """
+
+        if callable(map_or_callable):
+            if cache:
+                map_or_callable = functools.cache(map_or_callable)
+        else:
+            d = map_or_callable
+            map_or_callable = lambda ap: d.get(ap, ap)
+
+        for obj in self.objects:
+            if (aperture := getattr(obj, 'aperture', None)):
+                obj.aperture = map_or_callable(aperture)
+
+    def dedup_apertures(self, settings=None):
+        """ Merge all apertures and aperture macros in this layer that result in the same Gerber definition under the
+        given :py:class:~.FileSettings:.
+
+        When no explicit settings are given, uses Gerbonara's default settings.
+
+        :param settings: settings under which to de-duplicate the apertures.
+        """
+
+        if settings is None:
+            settings = FileSettings.defaults()
+
+        cache = {}
+        macro_names = set()
+        def lookup(aperture):
+            nonlocal cache, settings
+            if isinstance(aperture, apertures.ApertureMacroInstance):
+                macro = aperture.macro
+                macro_def = macro.to_gerber(settings)
+                if macro_def not in cache:
+                    cache[macro_def] = macro
+
+                    if macro.name in macro_names:
+                        macro._reset_name()
+                    macro_names.add(macro.name)
+
+                else:
+                    macro = cache[macro_def]
+                    aperture = dataclasses.replace(aperture, macro=macro)
+
+            code = aperture.to_gerber(settings)
+            if code not in cache:
+                cache[code] = aperture
+
+            return cache[code]
+
+        self.map_apertures(lookup)
+
+    def to_excellon(self, plated=None, errors='raise', holes_only=False):
+        """ Convert this excellon file into a :py:class:`~.excellon.ExcellonFile`. This will convert interpolated lines
+        into slots, and circular aperture flashes into holes. Other features such as ``G36`` polygons or flashes with
+        non-circular apertures will result in a :py:obj:`ValueError`. You can, of course, programmatically remove such
+        features from a :py:class:`GerberFile` before conversion. """
         new_objs = []
         new_tools = {}
         for obj in self.objects:
-            if not isinstance(obj, Line) or isinstance(obj, Arc) or isinstance(obj, Flash) or \
-                not isinstance(obj.aperture, CircleAperture):
-                raise ValueError('Cannot convert {type(obj)} to excellon!')
+            if holes_only and not isinstance(obj, go.Flash):
+                continue
 
-            if not (new_tool := new_tools.get(id(obj.aperture))):
+            if not isinstance(obj, (go.Line, go.Arc, go.Flash)) or \
+                not isinstance(getattr(obj, 'aperture', None), apertures.CircleAperture):
+                    if errors == 'raise':
+                        raise ValueError(f'Cannot convert {obj} to excellon.')
+                    elif errors == 'warn':
+                        warnings.warn(f'Gerber to Excellon conversion: Cannot convert {obj} to excellon.')
+                        continue
+                    elif errors == 'ignore':
+                        continue
+                    else:
+                        raise ValueError('Invalid "errors" parameter. Allowed values: "raise", "warn" or "ignore".')
+
+            if not (new_tool := new_tools.get(obj.aperture)):
                 # TODO plating?
-                new_tool = new_tools[id(obj.aperture)] = ExcellonTool(obj.aperture.diameter)
-            new_obj = dataclasses.replace(obj, aperture=new_tool)
+                new_tool = new_tools[obj.aperture] = apertures.ExcellonTool(obj.aperture.diameter, plated=plated, unit=obj.aperture.unit)
+            new_objs.append(dataclasses.replace(obj, aperture=new_tool))
             
         return ExcellonFile(objects=new_objs, comments=self.comments)
 
-    def to_gerber(self):
-        return
+    def to_gerber(self, errors='raise'):
+        """ Counterpart to :py:meth:`~.excellon.ExcellonFile.to_gerber`. Does nothing and returns :py:obj:`self`. """
+        return self
 
-    def merge(self, other):
+    def merge(self, other, mode='above', keep_settings=False):
+        """ Merge ``other`` into ``self``, i.e. add all objects that are in ``other`` to ``self``. This resets
+        :py:attr:`.import_settings` and :py:attr:`~.GerberFile.generator`. Units and other file-specific settings are
+        handled automatically.
+
+        :param mode: One of the strings :py:obj:`"above"` (default) or :py:obj:`"below"`, specifying whether the other
+            layer's objects will be placed above this layer's objects (placing them towards the end of the file), or
+            below this layer's objects (placing them towards the beginning of the file). This setting is only relevant
+            when there are overlapping objects of different polarity, otherwise the rendered result will be the same
+            either way.
+        """
         if other is None:
             return
 
-        self.import_settings = None
+        other = other.to_gerber()
+
+        if not keep_settings:
+            self.import_settings = None
         self.comments += other.comments
 
-        # dedup apertures
-        new_apertures = {}
-        replace_apertures = {}
-        mock_settings = FileSettings()
-        for ap in self.apertures + other.apertures:
-            gbr = ap.to_gerber(mock_settings)
-            if gbr not in new_apertures:
-                new_apertures[gbr] = ap
-            else:
-                replace_apertures[id(ap)] = new_apertures[gbr]
-        self.apertures = list(new_apertures.values())
+        # Join objects
+        if mode == 'below':
+            self.objects = other.objects + self.objects
+        elif mode == 'above':
+            self.objects += other.objects
+        else:
+            raise ValueError(f'Invalid mode "{mode}", must be one of "above" or "below".')
 
-        self.objects += other.objects
-        for obj in self.objects:
-            # If object has an aperture attribute, replace that aperture.
-            if (ap := replace_apertures.get(id(getattr(obj, 'aperture', None)))):
-                obj.aperture = ap
-
-        # dedup aperture macros
-        macros = { m.to_gerber(): m
-                for m in [ GenericMacros.circle, GenericMacros.rect, GenericMacros.obround, GenericMacros.polygon] }
-        for ap in new_apertures.values():
-            if isinstance(ap, apertures.ApertureMacroInstance):
-                macro_grb = ap.macro.to_gerber() # use native unit to compare macros
-                if macro_grb in macros:
-                    ap.macro = macros[macro_grb]
-                else:
-                    macros[macro_grb] = ap.macro
-
-        # make macro names unique
-        seen_macro_names = set()
-        for macro in macros.values():
-            i = 2
-            while (new_name := f'{macro.name}{i}') in seen_macro_names:
-                i += 1
-            macro.name = new_name
-            seen_macro_names.add(new_name)
+        self.dedup_apertures()
 
     def dilate(self, offset, unit=MM, polarity_dark=True):
         # TODO add tests for this
-        self.apertures = [ aperture.dilated(offset, unit) for aperture in self.apertures ]
+        self.map_apertures(lambda ap: ap.dilated(offset, unit))
 
-        offset_circle = CircleAperture(offset, unit=unit)
-        self.apertures.append(offset_circle)
-
-        new_primitives = []
-        for p in self.primitives:
-
-            p.polarity_dark = polarity_dark
+        offset_circle = apertures.CircleAperture(offset, unit=unit)
+        new_objects = []
+        for obj in self.objects:
+            obj.polarity_dark = polarity_dark
 
             # Ignore Line, Arc, Flash. Their actual dilation has already been done by dilating the apertures above.
-            if isinstance(p, Region):
-                ol = p.poly.outline
-                for start, end, arc_center in zip(ol, ol[1:] + ol[0], p.poly.arc_centers):
-                    if arc_center is not None:
-                        new_primitives.append(Arc(*start, *end, *arc_center,
-                            polarity_dark=polarity_dark, unit=p.unit, aperture=offset_circle))
-
-                    else:
-                        new_primitives.append(Line(*start, *end,
-                            polarity_dark=polarity_dark, unit=p.unit, aperture=offset_circle))
+            if isinstance(obj, Region):
+                new_objects.extend(obj.outline_objects(offset_circle))
 
         # it's safe to append these at the end since we compute a logical OR of opaque areas anyway.
-        self.primitives.extend(new_primitives)
+        self.objects.extend(new_objects)
 
     @classmethod
-    def open(kls, filename, enable_includes=False, enable_include_dir=None):
+    def open(kls, filename, enable_includes=False, enable_include_dir=None, override_settings=None):
         """ Load a Gerber file from the file system. The Gerber standard contains this wonderful and totally not
         insecure "include file" setting. We disable it by default and do not parse Gerber includes because a) nobody
         actually uses them, and b) they're a bad idea from a security point of view. In case you actually want these,
@@ -166,19 +249,21 @@ class GerberFile(CamFile):
         with open(filename, "r") as f:
             if enable_includes and enable_include_dir is None:
                 enable_include_dir = filename.parent
-            return kls.from_string(f.read(), enable_include_dir, filename=filename)
+            return kls.from_string(f.read(), enable_include_dir, filename=filename, override_settings=override_settings)
 
     @classmethod
-    def from_string(kls, data, enable_include_dir=None, filename=None):
+    def from_string(kls, data, enable_include_dir=None, filename=None, override_settings=None):
         """ Parse given string as Gerber file content. For the meaning of the parameters, see
         :py:meth:`~.GerberFile.open`. """
         # filename arg is for error messages
         obj = kls()
-        GerberParser(obj, include_dir=enable_include_dir).parse(data, filename=filename)
+        parser = GerberParser(obj, include_dir=enable_include_dir, override_settings=override_settings)
+        parser.parse(data, filename=filename)
         return obj
 
     def _generate_statements(self, settings, drop_comments=True):
         """ Export this file as Gerber code, yields one str per line. """
+
         yield 'G04 Gerber file generated by Gerbonara*'
         for name, value in self.file_attrs.items():
             attrdef = ','.join([name, *map(str, value)])
@@ -187,8 +272,10 @@ class GerberFile(CamFile):
 
         zeros = 'T' if settings.zeros == 'trailing' else 'L' # default to leading if "None" is specified
         notation = 'I' if settings.notation == 'incremental' else 'A' # default to absolute
-        number_format = str(settings.number_format[0]) + str(settings.number_format[1])
-        yield f'%FS{zeros}{notation}X{number_format}Y{number_format}*%'
+        num_int, num_frac = settings.number_format or (4,5)
+        assert 1 <= num_int <= 9
+        assert 1 <= num_frac <= 9
+        yield f'%FS{zeros}{notation}X{num_int}{num_frac}Y{num_int}{num_frac}*%'
         yield '%IPPOS*%'
         yield 'G75'
         yield '%LPD*%'
@@ -198,26 +285,26 @@ class GerberFile(CamFile):
             for cmt in self.comments:
                 yield f'G04{cmt}*'
 
-        # Always emit gerbonara's generic, rotation-capable aperture macro replacements for the standard C/R/O/P shapes.
-        # Unconditionally emitting these here is easier than first trying to figure out if we need them later,
-        # and they are only a few bytes anyway.
-        am_stmt = lambda macro: f'%AM{macro.name}*\n{macro.to_gerber(unit=settings.unit)}*\n%'
-        for macro in [ GenericMacros.circle, GenericMacros.rect, GenericMacros.obround, GenericMacros.polygon ]:
-            yield am_stmt(macro)
+        self.dedup_apertures()
 
-        processed_macros = set()
-        aperture_map = {}
-        for number, aperture in enumerate(self.apertures, start=10):
+        am_stmt = lambda macro: f'%AM{macro.name}*\n{macro.to_gerber(settings)}*\n%'
+        aperture_map = {ap: num for num, ap in enumerate(self.apertures(), start=10)}
 
-            if isinstance(aperture, apertures.ApertureMacroInstance):
-                macro_def = am_stmt(aperture._rotated().macro)
-                if macro_def not in processed_macros:
-                    processed_macros.add(macro_def)
-                    yield macro_def
+        if settings.calculate_out_all_aperture_macros:
+            adds = []
+            for aperture, number in aperture_map.items():
+                if isinstance(aperture, apertures.ApertureMacroInstance):
+                    aperture = aperture.calculate_out(settings.unit, macro_name=f'CALCM{number}')
+                    yield am_stmt(aperture.macro)
+                adds.append(f'%ADD{number}{aperture.to_gerber(settings)}*%')
+            yield from adds
 
-            yield f'%ADD{number}{aperture.to_gerber(settings)}*%'
+        else:
+            for macro in self.aperture_macros():
+                yield am_stmt(macro)
 
-            aperture_map[id(aperture)] = number
+            for aperture, number in aperture_map.items():
+                yield f'%ADD{number}{aperture.to_gerber(settings)}*%'
 
         def warn(msg, kls=SyntaxWarning):
             warnings.warn(msg, kls)
@@ -230,7 +317,7 @@ class GerberFile(CamFile):
 
     def __str__(self):
         name = f'{self.original_path.name} ' if self.original_path else ''
-        return f'<GerberFile {name}with {len(self.apertures)} apertures, {len(self.objects)} objects>'
+        return f'<GerberFile {name}with {len(list(self.apertures()))} apertures, {len(self.objects)} objects>'
 
     def __repr__(self):
         return str(self)
@@ -238,10 +325,10 @@ class GerberFile(CamFile):
     def save(self, filename, settings=None, drop_comments=True):
         """ Save this Gerber file to the file system. See :py:meth:`~.GerberFile.generate_gerber` for the meaning
         of the arguments. """
-        with open(filename, 'w', encoding='utf-8') as f: # Encoding is specified as UTF-8 by spec.
-            f.write(self.generate_gerber(settings, drop_comments=drop_comments))
+        with open(filename, 'wb') as f: # Encoding is specified as UTF-8 by spec.
+            f.write(self.write_to_bytes(settings, drop_comments=drop_comments))
 
-    def generate_gerber(self, settings=None, drop_comments=True):
+    def write_to_bytes(self, settings=None, drop_comments=True):
         """ Export to Gerber format. Uses either the file's original settings or sane default settings if you don't give
         any.
 
@@ -253,39 +340,47 @@ class GerberFile(CamFile):
         :rtype: str
         """
         if settings is None:
-            settings = self.import_settings.copy() or FileSettings()
-            settings.zeros = None
-            settings.number_format = (5,6)
-        return '\n'.join(self._generate_statements(settings, drop_comments=drop_comments))
+            if self.import_settings:
+                settings = self.import_settings.copy()
+                settings.zeros = None
+            else:
+                settings = FileSettings.defaults()
+        return '\n'.join(self._generate_statements(settings, drop_comments=drop_comments)).encode('utf-8')
 
     def __len__(self):
         return len(self.objects)
 
+    def scale(self, factor, unit=MM):
+        scaled_apertures = {}
+
+        self.map_apertures(lambda ap: ap.scaled(factor))
+
+        for obj in self.objects:
+            obj.scale(factor)
+
     def offset(self, dx=0,  dy=0, unit=MM):
         # TODO round offset to file resolution
         for obj in self.objects:
             obj.offset(dx, dy, unit)
 
-    def rotate(self, angle:'radian', center=(0,0), unit=MM):
+    def rotate(self, angle:'radian', cx=0, cy=0, unit=MM):
         if math.isclose(angle % (2*math.pi), 0):
             return
 
-        # First, rotate apertures. We do this separately from rotating the individual objects below to rotate each
-        # aperture exactly once.
-        for ap in self.apertures:
-            ap.rotation += angle
+        self.map_apertures(lambda ap: ap.rotated(angle))
 
         for obj in self.objects:
-            obj.rotate(angle, *center, unit)
+            obj.rotate(angle, cx, cy, unit)
 
     def invert_polarity(self):
         """ Invert the polarity (color) of each object in this file. """
         for obj in self.objects:
-            obj.polarity_dark = not p.polarity_dark
-    
+            obj.polarity_dark = not obj.polarity_dark
+
 
 class GraphicsState:
-    """ Internal class used to track Gerber processing state during import and export. """
+    """ Internal class used to track Gerber processing state during import and export.
+    """
 
     def __init__(self, warn, file_settings=None, aperture_map=None):
         self.image_polarity = 'positive' # IP image polarity; deprecated
@@ -368,7 +463,7 @@ class GraphicsState:
         obj = go.Flash(*self.map_coord(*self.point), self.aperture,
                 polarity_dark=self._polarity_dark,
                 unit=self.unit,
-                attrs=self.object_attrs)
+                attrs=copy.copy(self.object_attrs))
         return obj
 
     def interpolate(self, x, y, i=None, j=None, aperture=True, multi_quadrant=False):
@@ -394,13 +489,13 @@ class GraphicsState:
                 raise SyntaxError("i/j coordinates given for linear D01 operation (which doesn't take i/j)")
 
             return go.Line(*old_point, *self.map_coord(*self.point), aperture,
-                    polarity_dark=self._polarity_dark, unit=unit, attrs=self.object_attrs)
+                    polarity_dark=self._polarity_dark, unit=unit, attrs=copy.copy(self.object_attrs))
 
         else:
             if i is None and j is None:
                 self.warn('Linear segment implied during arc interpolation mode through D01 w/o I, J values')
                 return go.Line(*old_point, *self.map_coord(*self.point), aperture,
-                        polarity_dark=self._polarity_dark, unit=unit, attrs=self.object_attrs)
+                        polarity_dark=self._polarity_dark, unit=unit, attrs=copy.copy(self.object_attrs))
 
             else:
                 if i is None:
@@ -417,7 +512,7 @@ class GraphicsState:
                 if not multi_quadrant:
                     return go.Arc(*old_point, *new_point, *self.map_coord(i, j, relative=True),
                             clockwise=clockwise, aperture=(self.aperture if aperture else None),
-                            polarity_dark=self._polarity_dark, unit=unit, attrs=self.object_attrs)
+                            polarity_dark=self._polarity_dark, unit=unit, attrs=copy.copy(self.object_attrs))
 
                 else:
                     if math.isclose(old_point[0], new_point[0]) and math.isclose(old_point[1], new_point[1]):
@@ -430,7 +525,7 @@ class GraphicsState:
 
                     arc = lambda cx, cy: go.Arc(*old_point, *new_point, cx, cy,
                             clockwise=clockwise, aperture=aperture,
-                            polarity_dark=self._polarity_dark, unit=unit, attrs=self.object_attrs)
+                            polarity_dark=self._polarity_dark, unit=unit, attrs=copy.copy(self.object_attrs))
                     arcs = [ arc(cx, cy), arc(-cx, cy), arc(cx, -cy), arc(-cx, -cy) ]
                     arcs = sorted(arcs, key=lambda a: a.numeric_error())
 
@@ -469,9 +564,11 @@ class GraphicsState:
             yield '%LPD*%' if polarity_dark else '%LPC*%'
 
     def set_aperture(self, aperture):
-        if self.aperture != aperture:
+        ap_id = self.aperture_map[aperture]
+        old_ap_id = self.aperture_map.get(self.aperture, None)
+        if ap_id != old_ap_id:
             self.aperture = aperture
-            yield f'D{self.aperture_map[id(aperture)]}*'
+            yield f'D{ap_id}*'
 
     def set_current_point(self, point, unit=None):
         point_mm = MM(point[0], unit), MM(point[1], unit)
@@ -490,17 +587,20 @@ class GraphicsState:
 
     def interpolation_mode_statement(self):
         return {
-                InterpMode.LINEAR: 'G01',
-                InterpMode.CIRCULAR_CW: 'G02',
-                InterpMode.CIRCULAR_CCW: 'G03'}[self.interpolation_mode]
+                InterpMode.LINEAR: 'G01*',
+                InterpMode.CIRCULAR_CW: 'G02*',
+                InterpMode.CIRCULAR_CCW: 'G03*'}[self.interpolation_mode]
 
 
 class GerberParser:
-    """ Internal class that contains all of the actual Gerber parsing magic. """
+    """ Internal class that contains all of the actual Gerber parsing magic.
+    """
 
     NUMBER = r"[\+-]?\d+"
     DECIMAL = r"[\+-]?\d+([.]?\d+)?"
     NAME = r"[a-zA-Z_$\.][a-zA-Z_$\.0-9+\-]+"
+    MAX_STEP_REPEAT_INSTANCES = 100000
+    MAX_STEP_REPEAT_RESULT_OBJECTS = 100000
 
     STATEMENT_REGEXES = {
         'coord': fr"(G0?[123]|G74|G75|G54|G55)?\s*(?:X\+?(-?)({NUMBER}))?(?:Y\+?(-?)({NUMBER}))?" \
@@ -508,6 +608,7 @@ class GerberParser:
             fr"(?:D0?([123]))?$",
         'region_start': r'G36$',
         'region_end': r'G37$',
+        'eof': r"(D02)?M0?[02]", # P-CAD 2006 files have a spurious D02 before M02 as in "D02M02"
         'aperture': r"(G54|G55)?\s*D(?P<number>\d+)",
         # Allegro combines format spec and unit into one long illegal extended command.
         'allegro_format_spec': r"FS(?P<zero>(L|T|D))?(?P<notation>(A|I))[NG0-9]*X(?P<x>[0-7][0-7])Y(?P<y>[0-7][0-7])[DM0-9]*\*MO(?P<unit>IN|MM)",
@@ -528,26 +629,28 @@ class GerberParser:
         'aperture_definition': fr"ADD(?P<number>\d+)(?P<shape>C|R|O|P|{NAME})(,(?P<modifiers>[^,%]*))?$",
         'aperture_macro': fr"AM(?P<name>{NAME})\*(?P<macro>[^%]*)",
         'siemens_garbage': r'^ICAS$',
+        'step_repeat': fr'^SR(?P<coords>X(?P<X>[0-9]+)Y(?P<Y>[0-9]+)I(?P<I>{DECIMAL})J(?P<J>{DECIMAL}))?$',
         'old_unit':r'(?P<mode>G7[01])',
         'old_notation': r'(?P<mode>G9[01])',
-        'eof': r"M0?[02]",
         'ignored': r"(?P<stmt>M01)",
         # NOTE: The official spec says names can be empty or contain commas. I think that doesn't make sense.
-        'attribute': r"(?P<eagle_garbage>G04 #@! %)?(?P<type>TF|TA|TO|TD)(?P<name>[._$a-zA-Z][._$a-zA-Z0-9]*)(,(?P<value>.*))",
+        'attribute': r"(?P<eagle_garbage>G04 #@! %)?(?P<type>TF|TA|TO|TD)(?P<name>[._$a-zA-Z][._$a-zA-Z0-9]*)?(,(?P<value>.*))?",
         # Eagle file attributes handled above.
         'comment': r"G0?4(?P<comment>[^*]*)",
         }
 
-    def __init__(self, target, include_dir=None):
+    def __init__(self, target, include_dir=None, override_settings=None):
         """ Pass an include dir to enable IF include statements (potentially DANGEROUS!). """
         self.target = target
         self.include_dir = include_dir
         self.include_stack = []
-        self.file_settings = FileSettings()
+        self.file_settings = override_settings or FileSettings()
         self.graphics_state = GraphicsState(warn=self.warn, file_settings=self.file_settings)
         self.aperture_map = {}
         self.aperture_macros = {}
         self.current_region = None
+        self.step_repeat_coords = None
+        self.step_repeat_objects = None
         self.eof_found = False
         self.multi_quadrant_mode = None # used only for syntax checking
         self.macros = {}
@@ -609,7 +712,6 @@ class GerberParser:
                 self.warn(f'Unknown statement found: "{self._shorten_line()}", ignoring.', UnknownStatementWarning)
                 self.target.comments.append(f'Unknown statement found: "{self._shorten_line()}", ignoring.')
         
-        self.target.apertures = list(self.aperture_map.values())
         self.target.import_settings = self.file_settings
         self.target.unit = self.file_settings.unit
         self.target.file_attrs = self.file_attrs
@@ -691,7 +793,10 @@ class GerberParser:
                 # in multi-quadrant mode this may return None if start and end point of the arc are the same.
                 obj = self.graphics_state.interpolate(x, y, i, j, multi_quadrant=self.multi_quadrant_mode)
                 if obj is not None:
-                    self.target.objects.append(obj)
+                    if self.step_repeat_objects:
+                        self.step_repeat_objects.append(obj)
+                    else:
+                        self.target.objects.append(obj)
             else:
                 obj = self.graphics_state.interpolate(x, y, i, j, aperture=False, multi_quadrant=self.multi_quadrant_mode)
                 if obj is not None:
@@ -702,14 +807,21 @@ class GerberParser:
             if self.current_region:
                 # Start a new region for every outline. As gerber has no concept of fill rules or winding numbers,
                 # it does not make a graphical difference, and it makes the implementation slightly easier.
-                self.target.objects.append(self.current_region)
+                if self.step_repeat_objects:
+                    self.step_repeat_objects.append(self.current_region)
+                else:
+                    self.target.objects.append(self.current_region)
                 self.current_region = go.Region(
                         polarity_dark=self.graphics_state.polarity_dark,
                         unit=self.file_settings.unit)
 
         elif op == '3':
             if self.current_region is None:
-                self.target.objects.append(self.graphics_state.flash(x, y))
+                obj = self.graphics_state.flash(x, y) 
+                if self.step_repeat_objects:
+                    self.step_repeat_objects.append(obj)
+                else:
+                    self.target.objects.append(obj)
             else:
                 raise SyntaxError('DO3 flash statement inside region')
 
@@ -750,12 +862,17 @@ class GerberParser:
             if match['shape'] in 'RO' and (math.isclose(modifiers[0], 0) or math.isclose(modifiers[1], 0)):
                 self.warn('Definition of zero-width and/or zero-height rectangle or obround aperture. This is invalid according to spec.' )
 
-            new_aperture = kls(*modifiers, unit=self.file_settings.unit, attrs=self.aperture_attrs.copy(),
+            # Polygon aperture rotation is specified in degrees, but radians are easier to work with
+            if match['shape'] == 'P':
+                if len(modifiers) > 2:
+                    modifiers[2] = math.radians(modifiers[2])
+
+            new_aperture = kls(*modifiers, unit=self.file_settings.unit, attrs=tuple(self.aperture_attrs.items()),
                     original_number=number)
 
         elif (macro := self.aperture_macros.get(match['shape'])):
-            new_aperture = apertures.ApertureMacroInstance(macro, modifiers, unit=self.file_settings.unit,
-                    attrs=self.aperture_attrs.copy(), original_number=number)
+            new_aperture = apertures.ApertureMacroInstance(macro, tuple(modifiers), unit=self.file_settings.unit,
+                    attrs=tuple(self.aperture_attrs.items()), original_number=number)
 
         else:
             raise ValueError(f'Aperture shape "{match["shape"]}" is unknown')
@@ -767,19 +884,30 @@ class GerberParser:
                 match['name'], match['macro'], self.file_settings.unit)
     
     def _parse_format_spec(self, match):
-        # This is a common problem in Eagle files, so just suppress it
-        self.file_settings.zeros = {'L': 'leading', 'T': 'trailing'}.get(match['zero'], 'leading')
+        if self.file_settings.zeros is not None:
+            self.warn('Re-definition of zero suppression setting. Ignoring.')
+        else:
+            # This is a common problem in Eagle files, so just suppress it
+            self.file_settings.zeros = {'L': 'leading', 'T': 'trailing'}.get(match['zero'], 'leading')
+
         self.file_settings.notation = 'incremental' if match['notation'] == 'I' else 'absolute'
 
         if match['x'] != match['y']:
             raise SyntaxError(f'FS specifies different coordinate formats for X and Y ({match["x"]} != {match["y"]})')
-        self.file_settings.number_format = int(match['x'][0]), int(match['x'][1])
+
+        if self.file_settings.number_format != (None, None):
+            self.warn('Re-definition of number format setting. Ignoring.')
+        else:
+            self.file_settings.number_format = int(match['x'][0]), int(match['x'][1])
 
     def _parse_unit_mode(self, match):
-        if match['unit'] == 'MM':
-            self.graphics_state.unit = self.file_settings.unit = MM
+        if self.file_settings.unit is not None:
+            self.warn('Re-definition of file units. Ignoring.')
         else:
-            self.graphics_state.unit = self.file_settings.unit = Inch
+            if match['unit'] == 'MM':
+                self.graphics_state.unit = self.file_settings.unit = MM
+            else:
+                self.graphics_state.unit = self.file_settings.unit = Inch
 
     def _parse_allegro_format_spec(self, match):
         self._parse_format_spec(match)
@@ -955,11 +1083,40 @@ class GerberParser:
 
         else:
             target = {'TF': self.file_attrs, 'TO': self.graphics_state.object_attrs, 'TA': self.aperture_attrs}[match['type']]
-            target[match['name']] = match['value'].split(',')
+            target[match['name']] = tuple(match['value'].split(',')) if match['value'] else ()
 
             if 'EAGLE' in self.file_attrs.get('.GenerationSoftware', []) or match['eagle_garbage']:
                 self.generator_hints.append('eagle')
     
+    def _parse_step_repeat(self, match):
+        if match['coords']:
+            if self.step_repeat_coords:
+                raise SyntaxError('SR step-repeat called inside ongoing SR step-repeat')
+
+            x, y = int(match['X']), int(match['Y'])
+            i, j = float(match['I']), float(match['J'])
+            if x < 1 or y < 1:
+                raise SyntaxError('SR step-repeat X and Y values must be at least 1')
+            if x * y > self.MAX_STEP_REPEAT_INSTANCES:
+                raise SyntaxError('SR step-repeat expands to too many instances')
+
+            self.step_repeat_coords = (x, y, i, j)
+            self.step_repeat_objects = []
+
+        else:
+            x, y, i, j = self.step_repeat_coords
+            if len(self.step_repeat_objects) * x * y > self.MAX_STEP_REPEAT_RESULT_OBJECTS:
+                raise SyntaxError('SR step-repeat expands to too many objects')
+
+            for obj in self.step_repeat_objects:
+                for nx in range(x):
+                    for ny in range(y):
+                        new_obj = copy.copy(obj)
+                        new_obj.offset(i * nx, j * ny)
+                        self.target.objects.append(new_obj)
+            self.step_repeat_coords = None
+            self.step_repeat_objects = None
+
     def _parse_eof(self, match):
         self.eof_found = True
 

src/gerbonara/utils.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
-# Copyright 2022 Jan Götte <code@jaseg.de>
+# Copyright 2022 Jan Sebastian Götte <gerbonara@jaseg.de>
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -25,9 +25,11 @@ gerber.utils
 This module provides utility functions for working with Gerber and Excellon files.
 """
 
+from dataclasses import dataclass
 import os
 import re
 import textwrap
+from functools import reduce
 from enum import Enum
 import math
 
@@ -56,6 +58,7 @@ class RegexMatcher:
             return False
 
 
+@dataclass(frozen=True, slots=True)
 class LengthUnit:
     """ Convenience length unit class. Used in :py:class:`.GraphicObject` and :py:class:`.Aperture` to store lenght
     information. Provides a number of useful unit conversion functions.
@@ -63,10 +66,9 @@ class LengthUnit:
     Singleton, use only global instances ``utils.MM`` and ``utils.Inch``.
     """
 
-    def __init__(self, name, shorthand, this_in_mm):
-        self.name = name
-        self.shorthand = shorthand
-        self.factor = this_in_mm
+    name: str
+    shorthand: str
+    this_in_mm: float
 
     def convert_from(self, unit, value):
         """ Convert ``value`` from ``unit`` into this unit.
@@ -82,7 +84,7 @@ class LengthUnit:
         if unit == self or unit is None or value is None:
             return value
 
-        return value * unit.factor / self.factor
+        return value * unit.this_in_mm / self.this_in_mm
 
     def convert_to(self, unit, value):
         """ :py:meth:`.LengthUnit.convert_from` but in reverse. """
@@ -95,6 +97,32 @@ class LengthUnit:
 
         return unit.convert_from(self, value)
 
+    def convert_bounds_from(self, unit, value):
+        """ :py:meth:`.LengthUnit.convert_from` but for ((min_x, min_y), (max_x, max_y)) bounding box tuples. """
+
+        if value is None:
+            return None
+
+        (min_x, min_y), (max_x, max_y) = value
+        min_x = self.convert_from(unit, min_x)
+        min_y = self.convert_from(unit, min_y)
+        max_x = self.convert_from(unit, max_x)
+        max_y = self.convert_from(unit, max_y)
+        return (min_x, min_y), (max_x, max_y)
+
+    def convert_bounds_to(self, unit, value):
+        """ :py:meth:`.LengthUnit.convert_to` but for ((min_x, min_y), (max_x, max_y)) bounding box tuples. """
+
+        if value is None:
+            return None
+
+        (min_x, min_y), (max_x, max_y) = value
+        min_x = self.convert_to(unit, min_x)
+        min_y = self.convert_to(unit, min_y)
+        max_x = self.convert_to(unit, max_x)
+        max_y = self.convert_to(unit, max_y)
+        return (min_x, min_y), (max_x, max_y)
+
     def format(self, value):
         """ Return a human-readdable string representing value in this unit.
 
@@ -216,6 +244,59 @@ def rotate_point(x, y, angle, cx=0, cy=0):
             cy + (x - cx) * math.sin(-angle) + (y - cy) * math.cos(-angle))
 
 
+def sweep_angle(cx, cy, x1, y1, x2, y2, clockwise):
+    """ Calculate absolute sweep angle of arc. This is always a positive number.
+
+    :returns: Angle in clockwise radian between ``0`` and ``2*math.pi``
+    :rtype: float
+    """
+    x1, y1 = x1-cx, y1-cy
+    x2, y2 = x2-cx, y2-cy
+
+    a1, a2 = math.atan2(y1, x1), math.atan2(y2, x2)
+    f = abs(a2 - a1)
+    if not clockwise:
+        if a2 > a1:
+            return a2 - a1
+        else:
+            return 2*math.pi - abs(a2 - a1)
+    else:
+        if a1 > a2:
+            return a1 - a2
+        else:
+            return 2*math.pi - abs(a1 - a2)
+
+
+def approximate_arc(cx, cy, x1, y1, x2, y2, clockwise, max_error=1e-2, clip_max_error=True):
+    # TODO the max_angle calculation below is a bit off -- we over-estimate the error, and thus produce finer
+    # results than necessary. Fix this.
+        
+    r = math.dist((x1, y1), (cx, cy))
+
+    if clip_max_error:
+        # 1 - math.sqrt(1 - 0.5*math.sqrt(2))
+        max_error = min(max_error, r*0.4588038998538031)
+
+    elif max_error >= r:
+        yield (x1, y1)
+        yield (x2, y2)
+        return
+
+    # see https://www.mathopenref.com/sagitta.html
+    l = math.sqrt(r**2 - (r - max_error)**2)
+
+    angle_max = math.asin(l/r)
+    alpha = sweep_angle(cx, cy, x1, y1, x2, y2, clockwise)
+    num_segments = math.ceil(alpha / angle_max)
+    angle = alpha / num_segments
+
+    if not clockwise:
+        angle = -angle
+
+    for i in range(num_segments + 1):
+        yield rotate_point(x1, y1, i*angle, cx, cy)
+
+
 def min_none(a, b):
     """ Like the ``min(..)`` builtin, but if either value is ``None``, returns the other. """
     if a is None:
@@ -235,7 +316,7 @@ def max_none(a, b):
 
 
 def add_bounds(b1, b2):
-    """ Add/union two bounding boxes.
+    """ Add/union multiple bounding boxes.
 
     :param tuple b1: ``((min_x, min_y), (max_x, max_y))``
     :param tuple b2: ``((min_x, min_y), (max_x, max_y))``
@@ -244,10 +325,34 @@ def add_bounds(b1, b2):
     :rtype: tuple
     """
 
-    (min_x_1, min_y_1), (max_x_1, max_y_1) = b1
-    (min_x_2, min_y_2), (max_x_2, max_y_2) = b2
-    min_x, min_y = min_none(min_x_1, min_x_2), min_none(min_y_1, min_y_2)
-    max_x, max_y = max_none(max_x_1, max_x_2), max_none(max_y_1, max_y_2)
+    return sum_bounds((b1, b2))
+
+
+def offset_bounds(bounds, dx=0, dy=0):
+    (min_x, min_y), (max_x, max_y) = bounds
+    return (min_x+dx, min_y+dy), (max_x+dx, max_y+dy)
+
+
+def sum_bounds(bounds, *, default=None):
+    """ Add/union multiple bounding boxes.
+
+    :param bounds: each arg is one bounding box in ``((min_x, min_y), (max_x, max_y))`` format
+
+    :returns: ``((min_x, min_y), (max_x, max_y))``
+    :rtype: tuple
+    """
+
+    bounds = iter([ b for b in bounds if b is not None ])
+
+    for (min_x, min_y), (max_x, max_y) in bounds:
+        break
+    else:
+        return default
+
+    for (min_x_2, min_y_2), (max_x_2, max_y_2) in bounds:
+        min_x, min_y = min_none(min_x, min_x_2), min_none(min_y, min_y_2)
+        max_x, max_y = max_none(max_x, max_x_2), max_none(max_y, max_y_2)
+
     return ((min_x, min_y), (max_x, max_y))
 
 
@@ -256,6 +361,10 @@ class Tag:
     own implementation by passing a ``tag`` parameter. """
 
     def __init__(self, name, children=None, root=False, **attrs):
+        if (fill := attrs.get('fill')) and isinstance(fill, tuple):
+            attrs['fill'], attrs['fill-opacity'] = fill
+        if (stroke := attrs.get('stroke')) and isinstance(stroke, tuple):
+            attrs['stroke'], attrs['stroke-opacity'] = stroke
         self.name, self.attrs = name, attrs
         self.children = children or []
         self.root = root
@@ -284,11 +393,9 @@ def arc_bounds(x1, y1, x2, y2, cx, cy, clockwise):
     # This solution manages to handle circular arcs given in gerber format (with explicit center and endpoints, plus
     # sweep direction instead of a format with e.g. angles and radius) without any trigonometric functions (e.g. atan2).
     #
-    # cx, cy are relative to p1.
+    # cx, cy are in absolute coordinates.
 
     # Center arc on cx, cy
-    cx += x1
-    cy += y1
     x1 -= cx
     x2 -= cx
     y1 -= cy
@@ -298,6 +405,10 @@ def arc_bounds(x1, y1, x2, y2, cx, cy, clockwise):
     # Calculate radius
     r = math.sqrt(x1**2 + y1**2)
 
+    # Special case: Gerber defines an arc with p1 == p2 as a full circle.
+    if math.isclose(x1, x2) and math.isclose(y1, y2):
+        return (cx-r, cy-r), (cx+r, cy+r)
+
     # Calculate in which half-planes (north/south, west/east) P1 and P2 lie.
     # Note that we assume the y axis points upwards, as in Gerber and maths.
     # SVG has its y axis pointing downwards.
@@ -342,7 +453,7 @@ def arc_bounds(x1, y1, x2, y2, cx, cy, clockwise):
         # Since both points are on the arc (at same radius) in one halfplane, we can use the y coord as a proxy for
         # angle comparisons. 
         small_arc_is_north_to_south = y1 > y2
-        small_arc_is_clockwise = small_arc_is_north_to_south == p1_west
+        small_arc_is_clockwise = small_arc_is_north_to_south != p1_west
         if small_arc_is_clockwise != clockwise:
             min_y, max_y = -r, r # intersect aabb with both north and south
 
@@ -361,6 +472,33 @@ def arc_bounds(x1, y1, x2, y2, cx, cy, clockwise):
     return (min_x+cx, min_y+cy), (max_x+cx, max_y+cy)
 
 
+def convex_hull(points):
+    '''
+    Returns points on convex hull in CCW order according to Graham's scan algorithm. 
+    By Tom Switzer <thomas.switzer@gmail.com>.
+    '''
+    # https://gist.github.com/arthur-e/5cf52962341310f438e96c1f3c3398b8
+    TURN_LEFT, TURN_RIGHT, TURN_NONE = (1, -1, 0)
+
+    def cmp(a, b):
+        return (a > b) - (a < b)
+
+    def turn(p, q, r):
+        return cmp((q[0] - p[0])*(r[1] - p[1]) - (r[0] - p[0])*(q[1] - p[1]), 0)
+
+    def keep_left(hull, r):
+        while len(hull) > 1 and turn(hull[-2], hull[-1], r) != TURN_LEFT:
+            hull.pop()
+        if not len(hull) or hull[-1] != r:
+            hull.append(r)
+        return hull
+
+    points = sorted(points)
+    l = reduce(keep_left, points, [])
+    u = reduce(keep_left, reversed(points), [])
+    return l.extend(u[i] for i in range(1, len(u) - 1)) or l
+
+
 def point_line_distance(l1, l2, p):
     """ Calculate distance between infinite line through l1 and l2, and point p. """
     # https://en.wikipedia.org/wiki/Distance_from_a_point_to_a_line
@@ -374,29 +512,133 @@ def point_line_distance(l1, l2, p):
 
 
 def svg_arc(old, new, center, clockwise):
-    """ Format an SVG circular arc "A" path data entry given an arc in Gerber notation (i.e. with center relative to
-    first point).
+    """ Format an SVG circular arc "A" path data entry given an arc in Gerber notation (but with center in absolute
+    coordinates).
 
     :rtype: str
     """
-    r = math.hypot(*center)
+    r = float(math.dist(old, center))
     # invert sweep flag since the svg y axis is mirrored
     sweep_flag = int(not clockwise)
     # In the degenerate case where old == new, we always take the long way around. To represent this "full-circle arc"
     # in SVG, we have to split it into two.
     if math.isclose(math.dist(old, new), 0):
-        intermediate = old[0] + 2*center[0], old[1] + 2*center[1]
+        intermediate = old[0] + 2*(center[0]-old[0]), old[1] + 2*(center[1]-old[1])
         # Note that we have to preserve the sweep flag to avoid causing self-intersections by flipping the direction of
         # a circular cutin
-        return f'A {r:.6} {r:.6} 0 1 {sweep_flag} {intermediate[0]:.6} {intermediate[1]:.6} ' +\
-               f'A {r:.6} {r:.6} 0 1 {sweep_flag} {new[0]:.6} {new[1]:.6}'
+        return f'A {r:.6} {r:.6} 0 1 {sweep_flag} {float(intermediate[0]):.6} {float(intermediate[1]):.6} ' +\
+               f'A {r:.6} {r:.6} 0 1 {sweep_flag} {float(new[0]):.6} {float(new[1]):.6}'
 
     else: # normal case
-        d = point_line_distance(old, new, (old[0]+center[0], old[1]+center[1]))
+        d = point_line_distance(old, new, (center[0], center[1]))
         large_arc = int((d < 0) == clockwise)
-        return f'A {r:.6} {r:.6} 0 {large_arc} {sweep_flag} {new[0]:.6} {new[1]:.6}'
+        return f'A {r:.6} {r:.6} 0 {large_arc} {sweep_flag} {float(new[0]):.6} {float(new[1]):.6}'
 
 
 def svg_rotation(angle_rad, cx=0, cy=0):
-    return f'rotate({float(math.degrees(angle_rad)):.4} {float(cx):.6} {float(cy):.6})'
+    if math.isclose(angle_rad, 0.0, abs_tol=1e-3):
+        return {}
+    else:
+        return {'transform': f'rotate({float(math.degrees(angle_rad)):.4} {float(cx):.6} {float(cy):.6})'}
+
+def setup_svg(tags, bounds, margin=0, arg_unit=MM, svg_unit=MM, pagecolor='white', tag=Tag, inkscape=False):
+    (min_x, min_y), (max_x, max_y) = bounds
+
+    if margin:
+        margin = svg_unit(margin, arg_unit)
+        min_x -= margin
+        min_y -= margin
+        max_x += margin
+        max_y += margin
+
+    w, h = max_x - min_x, max_y - min_y
+    w = 1.0 if math.isclose(w, 0.0) else w
+    h = 1.0 if math.isclose(h, 0.0) else h
+
+    if inkscape:
+        tags.insert(0, tag('sodipodi:namedview', [], id='namedview1', pagecolor=pagecolor,
+                inkscape__document_units=svg_unit.shorthand))
+        namespaces = dict(
+            xmlns="http://www.w3.org/2000/svg",
+            xmlns__xlink="http://www.w3.org/1999/xlink",
+            xmlns__sodipodi='http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd',
+            xmlns__inkscape='http://www.inkscape.org/namespaces/inkscape')
+
+    else:
+        namespaces = dict(
+            xmlns="http://www.w3.org/2000/svg",
+            xmlns__xlink="http://www.w3.org/1999/xlink")
+
+    svg_unit = 'in' if svg_unit == 'inch' else 'mm'
+    # TODO export apertures as <uses> where reasonable.
+    return tag('svg', tags,
+            width=f'{w}{svg_unit}', height=f'{h}{svg_unit}',
+            viewBox=f'{min_x} {min_y} {w} {h}',
+            style=f'background-color:{pagecolor}',
+            **namespaces,
+            root=True)
+
+
+def point_in_polygon(point, poly):
+    # https://stackoverflow.com/questions/217578/how-can-i-determine-whether-a-2d-point-is-within-a-polygon
+    # https://wrfranklin.org/Research/Short_Notes/pnpoly.html
+
+    if not poly:
+        return False
+
+    res = False
+    tx, ty = point
+    xp, yp = poly[-1]
+    for x, y in poly:
+        if yp == ty == y and ((x > tx) != (xp > tx)): # test point on horizontal segment
+            return True
+        if xp == tx == x and ((y > ty) != (yp > ty)): # test point on vertical segment
+            return True
+        if ((y > ty) != (yp > ty)):
+            tmp = ((xp-x) * (ty-y) / (yp-y) + x)
+            if tx == tmp: # test point on diagonal segment
+                return True
+            elif tx < tmp:
+                res = not res
+        xp, yp = x, y
+
+    return res
+
+
+def polygon_area(poly):
+    # https://en.wikipedia.org/wiki/Shoelace_formula
+
+    if not poly or len(poly) < 3:
+        return 0
+
+    acc = 0
+    for (x1, y1), (x2, y2) in zip(poly, poly[-1:] + poly):
+        acc += (y1 + y2) * (x1 - x2)
+    return acc/2
+
+
+def bbox_intersect(a, b):
+    if a is None or b is None:
+        return False
+
+    (xa_min, ya_min), (xa_max, ya_max) = a
+    (xb_min, yb_min), (xb_max, yb_max) = b
+
+    x_overlap = not (xa_max < xb_min or xb_max < xa_min)
+    y_overlap = not (ya_max < yb_min or yb_max < ya_min)
+
+    return x_overlap and y_overlap
+
+
+def bbox_contains(outer, inner):
+    if outer is None or inner is None:
+        return False
+
+    (xa_min, ya_min), (xa_max, ya_max) = outer
+    (xb_min, yb_min), (xb_max, yb_max) = inner
+
+    contained_x = xa_min < xb_min and xb_max < xa_max
+    contained_y = ya_min < yb_min and yb_max < ya_max
+
+    return contained_x and contained_y
 

test2.py

@@ -0,0 +1,53 @@
+from gerbonara import *
+from shapely import *
+
+stack = layers.LayerStack.open('/home/jaseg/proj/ihsm-strain-gage-controller-hw/pcb/gerber')
+# Let's work in mm here. Gerbonara will take care to convert units when the file is in US customary units.
+(x1, y1), (x2, y2) = stack.bounding_box(unit=utils.MM)
+
+for l in [stack['bottom mask'], stack['top mask']]:
+
+    # The solder mask gerber layer by convention is "negative". That is, a "dark" polarity (drawn) Gerber primitive
+    # will result in an opening in the solder mask. Conversely, an empty gerber file would lead to the entire board
+    # being covered in solder mask.
+    #
+    # Here, we add a rectangle covering the entire board so the entire board is *free* of solder mask.
+
+    new = [graphic_objects.Region(
+        [(x1, y1), (x1, y2), (x2, y2), (x2, y1), (x1, y1)],
+        unit=utils.MM,
+        polarity_dark=True)]
+
+    # Iterate through all objects on the solder mask layer. In later KiCad versions, everything on the solder mask
+    # layer is exported as a Gerber region, which is a really bad idea, but makes things easy for us here.
+    for obj in l.objects:
+        if not obj.polarity_dark:
+            continue
+
+        if isinstance(obj, graphic_objects.Region):
+            regions = []
+        else:
+            regions = [graphic_objects.Region.from_arc_poly(prim.to_arc_poly())
+                for prim in obj.to_primitives(unit=utils.MM)]
+
+        for obj in regions:
+            # Convert the region to a shapely line string
+            ls = LineString(obj.outline).normalize()
+
+            # Ask shapely to offset the line string by 1 mm
+            out = ls.offset_curve(obj.unit(1, 'mm'))
+
+            # For negative offsets, this operation can result in an object being split up into multiple parts, so we
+            # might get back a MultiLineString instead of a LineString.
+            for ls in (out.geoms if hasattr(out, 'geoms') else [out]):
+
+                # Convert the resulting shapely object back to a Gerber region.
+                new.append(graphic_objects.Region(
+                    unit=obj.unit,
+                    polarity_dark=not obj.polarity_dark,
+                    outline=list(ls.coords)))
+
+    # Append the new objects to the original layer data
+    l.objects = new + l.objects
+# Write the modified layer stack to a new Gerber directory
+stack.save_to_directory('/tmp/out')

tests/.gitignore

@@ -0,0 +1 @@
+image_cache

tests/conftest.py

@@ -0,0 +1,172 @@
+
+import os
+from pathlib import Path
+import tqdm
+import multiprocessing.pool
+import subprocess
+from itertools import chain
+
+import pytest
+
+from .image_support import ImageDifference, run_cargo_cmd, ImageSupport
+
+
+@pytest.fixture
+def kicad_container(request):
+    return request.config.kicad_container
+
+
+@pytest.fixture()
+def kicad_footprints_libdir(request):
+    return request.config.kicad_footprints_libdir
+
+
+@pytest.fixture()
+def kicad_symbols_libdir(request):
+    return request.config.kicad_symbols_libdir
+
+
+@pytest.fixture()
+def img_support(request):
+    return request.config.image_support
+
+
+def pytest_assertrepr_compare(op, left, right):
+    if isinstance(left, ImageDifference) or isinstance(right, ImageDifference):
+        diff = left if isinstance(left, ImageDifference) else right
+        return [
+            f'Image difference assertion failed.',
+            f'    Calculated difference: {diff}',
+            f'    Histogram: {diff.histogram}', ]
+
+
+# store report in node object so tmp_gbr can determine if the test failed.
+@pytest.hookimpl(tryfirst=True, hookwrapper=True)
+def pytest_runtest_makereport(item, call):
+    outcome = yield
+    rep = outcome.get_result()
+    setattr(item, f'rep_{rep.when}', rep)
+
+
+fail_dir = Path('gerbonara_test_failures')
+def pytest_sessionstart(session):
+    if 'PYTEST_XDIST_WORKER' in os.environ: # only run this on the controller
+        return
+
+    for f in chain(fail_dir.glob('*.gbr'), fail_dir.glob('*.png')):
+        f.unlink()
+
+    try:
+        run_cargo_cmd('resvg', '--help', stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    except FileNotFoundError:
+        pytest.exit('resvg binary not found, aborting test.', 2)
+
+
+def _update_repo_cache(lib_dir, repo_url, tag):
+    if not lib_dir.is_dir():
+        print(f'Checking out KiCad footprint repo tag {tag}')
+        subprocess.run(['git', '-c', 'advice.detachedHead=false', 'clone', '--branch', tag, '--depth', '1', repo_url, str(lib_dir)], check=True)
+        return True
+
+    else:
+        print(f'Found cached KiCad footprint checkout, updating to {tag}')
+        res = subprocess.run(['git', '-C', str(lib_dir), 'rev-parse', 'HEAD', f'{tag}^{{commit}}'], check=True, capture_output=True, text=True)
+        head_commit, tag_commit = res.stdout.strip().splitlines()
+        print('got commits', head_commit, tag_commit)
+        if head_commit != tag_commit:
+            subprocess.run(['git', '-C', str(lib_dir), 'fetch', '--depth', '1', 'origin', tag], check=True)
+            subprocess.run(['git', '-c', 'advice.detachedHead=false', '-C', str(lib_dir), 'reset', '--hard', tag], check=True)
+            subprocess.run(['git', '-C', str(lib_dir), 'clean', '--force', '-d', '-x'], check=True)
+            return True
+        else:
+            print('Up to date, only cleaning.')
+            subprocess.run(['git', '-C', str(lib_dir), 'clean', '--force', '-d', '-x'], check=True)
+            return False
+
+
+def pytest_addoption(parser):
+    parser.addini('kicad_footprints_tag', 'git tag or branch for KiCad footprint library repo used as testdata', default='main')
+    parser.addini('kicad_symbols_tag', 'git tag or branch for KiCad symbol library repo used as testdata', default='main')
+    parser.addini('kicad_container_tag', 'docker hub tag for the KiCad container to use for exporting footprint images', default='main')
+    parser.addini('kicad_source_tag', 'git tag for the KiCad source repo whose demos directory is used as testdata', default='main')
+    parser.addoption("--use-cached-data", action="store_true", help="Do not re-check git repo caches and podman image")
+
+
+def pytest_configure(config):
+    os.nice(20)
+    # Resvg can sometimes consume a lot of memory. Make sure we don't kill the user's session.
+    if (oom_adj := Path('/proc/self/oom_adj')).is_file():
+        oom_adj.write_text('15\n')
+
+    if (lib_dir := os.environ.get('KICAD_FOOTPRINTS')):
+        config.kicad_footprints_libdir = Path(lib_dir).expanduser()
+    else:
+        config.kicad_footprints_libdir = config.cache.mkdir('kicad-footprints') / 'repo'
+
+    if (lib_dir := os.environ.get('KICAD_SYMBOLS')):
+        config.kicad_symbols_libdir = Path(lib_dir).expanduser()
+    else:
+        config.kicad_symbols_libdir = config.cache.mkdir('kicad-symbols') / 'repo'
+
+    if (lib_dir := os.environ.get('KICAD_SOURCE')):
+        config.kicad_source_dir = Path(lib_dir).expanduser()
+    else:
+        config.kicad_source_dir = config.cache.mkdir('kicad-source') / 'repo'
+
+    did_updates = False
+    is_pytest_controller = 'PYTEST_XDIST_WORKER' not in os.environ
+    if is_pytest_controller and not config.getoption("--use-cached-data"):
+        # Update cached library repos unless they are overridden from outside.
+        if not os.environ.get('KICAD_FOOTPRINTS'):
+            tag = config.getini('kicad_footprints_tag')
+            did_updates |= _update_repo_cache(config.kicad_footprints_libdir, 'https://gitlab.com/kicad/libraries/kicad-footprints', tag)
+
+        if not os.environ.get('KICAD_SYMBOLS'):
+            tag = config.getini('kicad_symbols_tag')
+            did_updates |= _update_repo_cache(config.kicad_symbols_libdir, 'https://gitlab.com/kicad/libraries/kicad-symbols', tag)
+
+        if not os.environ.get('KICAD_SOURCE'):
+            tag = config.getini('kicad_source_tag')
+            did_updates |= _update_repo_cache(config.kicad_source_dir, 'https://gitlab.com/kicad/code/kicad', tag)
+
+    tag = config.getini("kicad_container_tag")
+    config.kicad_container = os.environ.get('KICAD_CONTAINER', f'registry.hub.docker.com/kicad/kicad:{tag}')
+
+    if is_pytest_controller and not config.getoption("--use-cached-data"):
+        print('Checking podman image')
+        res = subprocess.run(['podman', 'image', 'exists', config.kicad_container])
+        if res.returncode:
+            print('Updating podman image')
+            subprocess.run(['podman', 'pull', config.kicad_container], check=True)
+            did_updates = True
+        else:
+            print('Up to date.')
+
+    config.image_support = ImageSupport(config.cache.mkdir('image_cache'), config.kicad_container)
+
+    if is_pytest_controller and did_updates and not config.getoption("--use-cached-data"):
+        print('Checking KiCad footprint library render cache')
+        with multiprocessing.pool.ThreadPool() as pool: # use thread pool here since we're only monitoring podman processes 
+            lib_dirs = list(config.kicad_footprints_libdir.glob('*.pretty'))
+            res = list(tqdm.tqdm(pool.imap(lambda path: config.image_support.bulk_populate_kicad_fp_export_cache(path), lib_dirs), total=len(lib_dirs)))
+
+
+def pytest_generate_tests(metafunc):
+    if 'kicad_library_file' in metafunc.fixturenames:
+        library_files = list(metafunc.config.kicad_symbols_libdir.glob('*.kicad_sym'))
+        metafunc.parametrize('kicad_library_file', library_files, ids=list(map(str, library_files)))
+
+    if 'kicad_mod_file' in metafunc.fixturenames:
+        mod_files = list(metafunc.config.kicad_footprints_libdir.glob('*.pretty/*.kicad_mod'))
+        metafunc.parametrize('kicad_mod_file', mod_files, ids=list(map(str, mod_files)))
+
+    if 'kicad_sch_file' in metafunc.fixturenames:
+        files = list(metafunc.config.kicad_source_dir.glob('demos/*.kicad_sch'))
+        files += list(metafunc.config.kicad_source_dir.glob('qa/data/**/*.kicad_sch'))
+        metafunc.parametrize('kicad_sch_file', files, ids=list(map(str, files)))
+
+    if 'kicad_pcb_file' in metafunc.fixturenames:
+        files = list(metafunc.config.kicad_source_dir.glob('demos/*.kicad_pcb'))
+        files += list(metafunc.config.kicad_source_dir.glob('qa/data/**/*.kicad_pcb'))
+        metafunc.parametrize('kicad_pcb_file', files, ids=list(map(str, files)))
+