Advanced svg/gerber composition working

TODO

@@ -0,0 +1,2 @@
+[ ] Do not just return "error 255" if usvg is not installed
+[ ] Straighten up svg-flatten input unit handling

gerbolyze/gerbolyze.py

@@ -95,7 +95,9 @@ def paste_vectors(input_gerbers, output_gerbers, top, bottom,
                 outfile = Path('debug') / f'dilated-{layer}-{amount}.gbr' # FIXME
                 # outfile = tmpdir / 'dilated-{layer}-{amount}.gbr'
                 dilate_gerber(layers, layer, amount, bbox, tmpdir, outfile, units)
-                return gerberex.read(str(outfile))
+                gbr = gerberex.read(str(outfile))
+                # gbr.offset(bounds[0][0], bounds[1][0])
+                return gbr
             
             for layer, input_files in layers.items():
                 if layer == 'drill':
@@ -510,19 +512,28 @@ def create_template_from_svg(bounds, svg_data, extra_layers=DEFAULT_EXTRA_LAYERS
 #==================
 
 def dilate_gerber(layers, layer_name, dilation, bbox, tmpdir, outfile, units):
-    # render gerber to SVG
-    scale  = 1/25.4 if units == 'metric' else 1.0 # pcb-tools gerber scale
-    scale *= CAIRO_SVG_HARDCODED_DPI
+    if layer_name not in layers:
+        raise ValueError(f'Cannot dilate layer {layer_name}: layer not found in input dir')
 
     bounds = get_bounds(bbox, layers)
-    ctx = GerberCairoContext(scale=scale)
-    for _path, to_render in layers.get(layer_name, ()):
-        ctx.render_layer(to_render, bounds=bounds,
-                settings=gerber.render.RenderSettings(color=(0,0,0)), # FIXME should be 1, 1, 1
-                bgsettings=gerber.render.RenderSettings(color=(0,0,0), alpha=0))
+    (x_min_mm, x_max_mm), (y_min_mm, y_max_mm) = bounds
+
+    origin_x = x_min_mm / MM_PER_INCH
+    origin_y = y_min_mm / MM_PER_INCH
+
+    width = (x_max_mm - x_min_mm) / MM_PER_INCH
+    height = (y_max_mm - y_min_mm) / MM_PER_INCH
 
     tmpfile = tmpdir / 'dilate-tmp.svg'
-    ctx.dump(str(tmpfile))
+    path, _gbr = layers[layer_name][0]
+    # NOTE: gerbv has an undocumented maximum length of 20 chars for the arguments to --origin and --window_inch
+    cmd = ['gerbv', '-x', 'svg',
+        '--border=0',
+        f'--origin={origin_x:.6f}x{origin_y:.6f}', f'--window_inch={width:.6f}x{height:.6f}',
+        '--foreground=#ffffff',
+        '-o', str(tmpfile), str(path)]
+    print('cmd:', " ".join(cmd))
+    subprocess.run(cmd, check=True)
 
     # FIXME DEBUG
     import uuid
@@ -531,9 +542,10 @@ def dilate_gerber(layers, layer_name, dilation, bbox, tmpdir, outfile, units):
     print('tmp debug dilation svg:', fn)
 
     # dilate & render back to gerber
-    svg_to_gerber(tmpfile, outfile, dilate=dilation)
+    # TODO: the scale parameter is a hack. ideally we would fix svg-flatten to handle input units correctly.
+    svg_to_gerber(tmpfile, outfile, dilate=-dilation, dpi=72, scale=25.4/72.0)
 
-def svg_to_gerber(infile, outfile, layer=None, trace_space:'mm'=0.1, vectorizer=None, vectorizer_map=None, exclude_groups=None, dilate=None):
+def svg_to_gerber(infile, outfile, layer=None, trace_space:'mm'=0.1, vectorizer=None, vectorizer_map=None, exclude_groups=None, dilate=None, dpi=None, scale=None):
     if 'SVG_FLATTEN' in os.environ:
         candidates = [os.environ['SVG_FLATTEN']]
 
@@ -560,6 +572,10 @@ def svg_to_gerber(infile, outfile, layer=None, trace_space:'mm'=0.1, vectorizer=
         args += ['--exclude-groups', exclude_groups]
     if dilate:
         args += ['--dilate', str(dilate)]
+    if dpi:
+        args += ['--usvg-dpi', str(dpi)]
+    if scale:
+        args += ['--scale', str(scale)]
 
     args += [str(infile), str(outfile)]
     print('full args:', " ".join(args))

svg-flatten/include/gerbolyze.hpp

@@ -213,7 +213,7 @@ namespace gerbolyze {
 
     class SimpleGerberOutput : public StreamPolygonSink {
     public:
-        SimpleGerberOutput(std::ostream &out, bool only_polys=false, int digits_int=4, int digits_frac=6, d2p offset={0,0});
+        SimpleGerberOutput(std::ostream &out, bool only_polys=false, int digits_int=4, int digits_frac=6, double scale=1.0, d2p offset={0,0});
         virtual ~SimpleGerberOutput() {}
         virtual SimpleGerberOutput &operator<<(const Polygon &poly);
         virtual SimpleGerberOutput &operator<<(GerberPolarityToken pol);
@@ -227,6 +227,7 @@ namespace gerbolyze {
         double m_height;
         long long int m_gerber_scale;
         d2p m_offset;
+        double m_scale;
     };
 
     class SimpleSVGOutput : public StreamPolygonSink {

svg-flatten/src/main.cpp

@@ -82,6 +82,12 @@ int main(int argc, char **argv) {
             {"skip_usvg", {"--no-usvg"},
                 "Do not preprocess input using usvg (do not use unless you know *exactly* what you're doing)",
                 0},
+            {"usvg_dpi", {"--usvg-dpi"},
+                "Passed through to usvg's --dpi, in case the input file has different ideas of DPI than usvg has.",
+                1},
+            {"scale", {"--scale"},
+                "Scale input svg lengths by this factor.",
+                1},
             {"exclude_groups", {"-e", "--exclude-groups"},
                 "Comma-separated list of group IDs to exclude from export. Takes precedence over --only-groups.",
                 1},
@@ -176,7 +182,9 @@ int main(int argc, char **argv) {
         sink = new SimpleSVGOutput(*out_f, only_polys, precision, dark_color, clear_color);
 
     } else if (fmt == "gbr" || fmt == "grb" || fmt == "gerber") {
-        sink = new SimpleGerberOutput(*out_f, only_polys, 4, precision);
+        double scale = args["scale"].as<double>(1.0);
+        cerr << "loading @scale=" << scale << endl;
+        sink = new SimpleGerberOutput(*out_f, only_polys, 4, precision, scale);
 
     } else if (fmt == "s-exp" || fmt == "sexp" || fmt == "kicad") {
         if (!args["sexp_mod_name"]) {
@@ -334,7 +342,13 @@ int main(int argc, char **argv) {
 
     } else {
         cerr << "calling usvg on " << barf << " and " << frob << endl; 
-        const char *command_line[] = {"usvg", "--keep-named-groups", barf.c_str(), frob.c_str(), NULL};
+        int dpi = 96;
+        if (args["usvg_dpi"]) {
+            dpi = args["usvg_dpi"].as<int>();
+        }
+        string dpi_str = to_string(dpi);
+        
+        const char *command_line[] = {"usvg", "--keep-named-groups", "--dpi", dpi_str.c_str(), barf.c_str(), frob.c_str(), NULL};
         struct subprocess_s subprocess;
         int rc = subprocess_create(command_line, subprocess_option_inherit_environment, &subprocess);
         if (rc) {

svg-flatten/src/out_dilater.cpp

@@ -52,10 +52,6 @@ Dilater &Dilater::operator<<(GerberPolarityToken pol) {
 }
 
 Dilater &Dilater::operator<<(const Polygon &poly) {
-    static int i = 0;
-    cerr << "dilating poly " << i++ << endl;
-
-    cerr << "got poly of " << poly.size() << " nodes" << endl;
     ClipperLib::Path poly_c;
     for (auto &p : poly) {
         poly_c.push_back({(ClipperLib::cInt)round(p[0] * clipper_scale), (ClipperLib::cInt)round(p[1] * clipper_scale)});

svg-flatten/src/out_gerber.cpp

@@ -27,11 +27,12 @@
 using namespace gerbolyze;
 using namespace std;
 
-SimpleGerberOutput::SimpleGerberOutput(ostream &out, bool only_polys, int digits_int, int digits_frac, d2p offset)
+SimpleGerberOutput::SimpleGerberOutput(ostream &out, bool only_polys, int digits_int, int digits_frac, double scale, d2p offset)
     : StreamPolygonSink(out, only_polys),
     m_digits_int(digits_int),
     m_digits_frac(digits_frac),
-    m_offset(offset)
+    m_offset(offset),
+    m_scale(scale)
 {
     assert(1 <= digits_int && digits_int <= 9);
     assert(0 <= digits_frac && digits_frac <= 9);
@@ -39,10 +40,10 @@ SimpleGerberOutput::SimpleGerberOutput(ostream &out, bool only_polys, int digits
 }
 
 void SimpleGerberOutput::header_impl(d2p origin, d2p size) {
-    m_offset[0] += origin[0];
-    m_offset[1] += origin[1];
-    m_width = size[0] - origin[0];
-    m_height = size[1] - origin[1];
+    m_offset[0] += origin[0] * m_scale;
+    m_offset[1] += origin[1] * m_scale;
+    m_width = (size[0] - origin[0]) * m_scale;
+    m_height = (size[1] - origin[1]) * m_scale;
     
     if (pow(10, m_digits_int-1) < max(m_width, m_height)) {
         cerr << "Warning: Input has bounding box too large for " << m_digits_int << "." << m_digits_frac << " gerber resolution!" << endl;
@@ -74,16 +75,16 @@ SimpleGerberOutput& SimpleGerberOutput::operator<<(const Polygon &poly) {
     }
 
     /* NOTE: Clipper and gerber both have different fixed-point scales. We get points in double mm. */
-    double x = round((poly[0][0] + m_offset[0]) * m_gerber_scale);
-    double y = round((m_height - poly[0][1] + m_offset[1]) * m_gerber_scale);
+    double x = round((poly[0][0] * m_scale + m_offset[0]) * m_gerber_scale);
+    double y = round((m_height - poly[0][1] * m_scale + m_offset[1]) * m_gerber_scale);
     m_out << "G36*" << endl;
     m_out << "X" << setw(m_digits_int + m_digits_frac) << setfill('0') << (long long int)x
           << "Y" << setw(m_digits_int + m_digits_frac) << setfill('0') << (long long int)y
           << "D02*" << endl;
     m_out << "G01*" << endl;
     for (size_t i=1; i<poly.size(); i++) {
-        double x = round((poly[i][0] + m_offset[0]) * m_gerber_scale);
-        double y = round((m_height - poly[i][1] + m_offset[1]) * m_gerber_scale);
+        double x = round((poly[i][0] * m_scale + m_offset[0]) * m_gerber_scale);
+        double y = round((m_height - poly[i][1] * m_scale + m_offset[1]) * m_gerber_scale);
         m_out << "X" << setw(m_digits_int + m_digits_frac) << setfill('0') << (long long int)x
               << "Y" << setw(m_digits_int + m_digits_frac) << setfill('0') << (long long int)y
               << "D01*" << endl;