gerbolyze/src/svg_pattern.cpp
2021-01-27 01:26:54 +01:00

113 lines
4.4 KiB
C++

/*
* This file is part of gerbolyze, a vector image preprocessing toolchain
* Copyright (C) 2021 Jan Sebastian Götte <gerbolyze@jaseg.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include "svg_import_util.h"
#include "svg_pattern.h"
#include "svg_import_defs.h"
#include "svg_geom.h"
#include <gerbolyze.hpp>
using namespace std;
gerbolyze::Pattern::Pattern(const pugi::xml_node &node, SVGDocument &doc) : _node(node), doc(&doc) {
/* Read pattern attributes from SVG node */
cerr << "creating pattern for node with id \"" << node.attribute("id").value() << "\"" << endl;
x = usvg_double_attr(node, "x");
y = usvg_double_attr(node, "y");
w = usvg_double_attr(node, "width");
h = usvg_double_attr(node, "height");
patternTransform = node.attribute("patternTransform").value();
string vb_s(node.attribute("viewBox").value());
has_vb = !vb_s.empty();
if (has_vb) {
istringstream vb_stream(vb_s);
vb_stream >> vb_x >> vb_y >> vb_w >> vb_h;
}
patternUnits = map_str_to_units(node.attribute("patternUnits").value(), SVG_ObjectBoundingBox);
patternContentUnits = map_str_to_units(node.attribute("patternContentUnits").value(), SVG_UserSpaceOnUse);
}
/* Tile pattern into gerber. Note that this function may be called several times in case the pattern is
* referenced from multiple places, so we must not clobber any of the object's state. */
void gerbolyze::Pattern::tile (const gerbolyze::RenderSettings &rset, ClipperLib::Paths &clip) {
assert(doc);
cairo_t *cr = doc->cairo();
assert(cr);
cairo_save(cr);
/* Transform x, y, w, h from pattern coordinate space into parent coordinates by applying the inverse
* patternTransform. This is necessary so we iterate over the correct bounds when tiling below */
cairo_matrix_t mat;
load_cairo_matrix_from_svg(patternTransform, mat);
if (cairo_matrix_invert(&mat) != CAIRO_STATUS_SUCCESS) {
cerr << "Cannot invert patternTransform matrix on pattern \"" << _node.attribute("id").value() << "\"." << endl;
cairo_restore(cr);
}
double inst_x = x, inst_y = y, inst_w = w, inst_h = h;
cairo_user_to_device(cr, &inst_x, &inst_y);
cairo_user_to_device_distance(cr, &inst_w, &inst_h);
cairo_restore(cr);
ClipperLib::IntRect clip_bounds = get_paths_bounds(clip);
double bx = clip_bounds.left / clipper_scale;
double by = clip_bounds.top / clipper_scale;
double bw = (clip_bounds.right - clip_bounds.left) / clipper_scale;
double bh = (clip_bounds.bottom - clip_bounds.top) / clipper_scale;
if (patternUnits == SVG_ObjectBoundingBox) {
inst_x *= bw;
inst_y *= bh;
inst_w *= bw;
inst_h *= bh;
}
/* Switch to pattern coordinates */
cairo_save(cr);
cairo_translate(cr, bx, by);
apply_cairo_transform_from_svg(cr, patternTransform);
/* Iterate over all pattern tiles in pattern coordinates */
for (double inst_off_x = fmod(inst_x, inst_w) - inst_w;
inst_off_x < bw + inst_w;
inst_off_x += inst_w) {
for (double inst_off_y = fmod(inst_y, inst_h) - inst_h;
inst_off_y < bh + inst_h;
inst_off_y += inst_h) {
cairo_save(cr);
/* Change into this individual tile's coordinate system */
cairo_translate(cr, inst_off_x, inst_off_y);
if (has_vb) {
cairo_translate(cr, vb_x, vb_y);
cairo_scale(cr, inst_w / vb_w, inst_h / vb_h);
} else if (patternContentUnits == SVG_ObjectBoundingBox) {
cairo_scale(cr, bw, bh);
}
/* Export the pattern tile's content like a group */
doc->export_svg_group(rset, _node, clip);
cairo_restore(cr);
}
}
cairo_restore(cr);
}