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author | jaseg <git@jaseg.de> | 2021-01-30 20:01:00 +0100 |
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committer | jaseg <git@jaseg.de> | 2021-01-30 20:01:00 +0100 |
commit | 2133867c8a86337c6668f9cfff06e4de9bd0bcce (patch) | |
tree | a8d1a9b41f7ae18a5a258e139635e4c54a990fc7 /src/svg_path.cpp | |
parent | 617a42a674bea6fcd90e19092303ce89acf4206e (diff) | |
download | gerbolyze-2133867c8a86337c6668f9cfff06e4de9bd0bcce.tar.gz gerbolyze-2133867c8a86337c6668f9cfff06e4de9bd0bcce.tar.bz2 gerbolyze-2133867c8a86337c6668f9cfff06e4de9bd0bcce.zip |
Reorg: move svg-flatten files into subdir
Diffstat (limited to 'src/svg_path.cpp')
-rw-r--r-- | src/svg_path.cpp | 213 |
1 files changed, 0 insertions, 213 deletions
diff --git a/src/svg_path.cpp b/src/svg_path.cpp deleted file mode 100644 index 537b5dd..0000000 --- a/src/svg_path.cpp +++ /dev/null @@ -1,213 +0,0 @@ -/* - * 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 <cmath> -#include <assert.h> -#include <iostream> -#include <sstream> -#include "cairo_clipper.hpp" -#include "svg_import_defs.h" -#include "svg_path.h" - -using namespace std; - -static void clipper_add_cairo_path(cairo_t *cr, ClipperLib::Clipper &c, bool closed) { - ClipperLib::Paths in_poly; - ClipperLib::cairo::cairo_to_clipper(cr, in_poly, CAIRO_PRECISION, ClipperLib::cairo::tNone); - c.AddPaths(in_poly, ClipperLib::ptSubject, closed); -} - -static void path_to_clipper_via_cairo(cairo_t *cr, ClipperLib::Clipper &c, const pugi::char_t *path_data) { - istringstream d(path_data); - - string cmd; - double x, y, c1x, c1y, c2x, c2y; - - bool first = true; - bool path_is_empty = true; - while (!d.eof()) { - d >> cmd; - assert (!d.fail()); - assert(!first || cmd == "M"); - - if (cmd == "Z") { /* Close path */ - cairo_close_path(cr); - clipper_add_cairo_path(cr, c, /* closed= */ true); - cairo_new_path(cr); - path_is_empty = true; - - } else if (cmd == "M") { /* Move to */ - d >> x >> y; - /* We need to transform all points ourselves here, and cannot use the transform feature of cairo_to_clipper: - * Our transform may contain offsets, and clipper only passes its data into cairo's transform functions - * after scaling up to its internal fixed-point ints, but it does not scale the transform accordingly. This - * means a scale/rotation we set before calling clipper works out fine, but translations get lost as they - * get scaled by something like 1e-6. - */ - cairo_user_to_device(cr, &x, &y); - assert (!d.fail()); - if (!first) - clipper_add_cairo_path(cr, c, /* closed= */ false); - cairo_new_path (cr); - path_is_empty = true; - cairo_move_to(cr, x, y); - - } else if (cmd == "L") { /* Line to */ - d >> x >> y; - cairo_user_to_device(cr, &x, &y); - assert (!d.fail()); - cairo_line_to(cr, x, y); - path_is_empty = false; - - } else { /* Curve to */ - assert(cmd == "C"); - d >> c1x >> c1y; /* first control point */ - cairo_user_to_device(cr, &c1x, &c1y); - d >> c2x >> c2y; /* second control point */ - cairo_user_to_device(cr, &c2x, &c2y); - d >> x >> y; /* end point */ - cairo_user_to_device(cr, &x, &y); - assert (!d.fail()); - cairo_curve_to(cr, c1x, c1y, c2x, c2y, x, y); - path_is_empty = false; - } - - first = false; - } - if (!path_is_empty) { - cairo_close_path(cr); - clipper_add_cairo_path(cr, c, /* closed= */ false); - } -} - -void gerbolyze::load_svg_path(cairo_t *cr, const pugi::xml_node &node, ClipperLib::PolyTree &ptree) { - auto *path_data = node.attribute("d").value(); - auto fill_rule = clipper_fill_rule(node); - - /* For open paths, clipper does not correctly remove self-intersections. Thus, we pass everything into - * clipper twice: Once with all paths set to "closed" to compute fill areas, and once with correct - * open/closed properties for stroke offsetting. */ - cairo_set_tolerance (cr, 0.1); /* FIXME make configurable, scale properly for units */ - cairo_set_fill_rule(cr, CAIRO_FILL_RULE_WINDING); - - ClipperLib::Clipper c; - c.StrictlySimple(true); - path_to_clipper_via_cairo(cr, c, path_data); - /* We canont clip the polygon here since that would produce incorrect results for our stroke. */ - c.Execute(ClipperLib::ctUnion, ptree, fill_rule, ClipperLib::pftNonZero); -} - -void gerbolyze::parse_dasharray(const pugi::xml_node &node, vector<double> &out) { - out.clear(); - - string val(node.attribute("stroke-dasharray").value()); - if (val.empty() || val == "none") - return; - - istringstream desc_stream(val); - while (!desc_stream.eof()) { - /* usvg says the array only contains unitless (px) values. I don't know what resvg does with percentages inside - * dash arrays. We just assume everything is a unitless number here. In case usvg passes through percentages, - * well, bad luck. They are a kind of weird thing inside a dash array in the first place. */ - double d; - desc_stream >> d; - out.push_back(d); - } - - assert(out.size() % 2 == 0); /* according to resvg spec */ -} - -/* Take a Clipper path in clipper-scaled document units, and apply the given SVG dash array to it. Do this by walking - * the path from start to end while emitting dashes. */ -void gerbolyze::dash_path(const ClipperLib::Path &in, ClipperLib::Paths &out, const vector<double> dasharray, double dash_offset) { - out.clear(); - if (dasharray.empty() || in.size() < 2) { - out.push_back(in); - return; - } - - size_t dash_idx = 0; - size_t num_dashes = dasharray.size(); - while (dash_offset > dasharray[dash_idx]) { - dash_offset -= dasharray[dash_idx]; - dash_idx = (dash_idx + 1) % num_dashes; - } - - double dash_remaining = dasharray[dash_idx] - dash_offset; - - ClipperLib::Path current_dash; - current_dash.push_back(in[0]); - double dbg_total_len = 0.0; - for (size_t i=1; i<in.size(); i++) { - ClipperLib::IntPoint p1(in[i-1]), p2(in[i]); - - double x1 = p1.X / clipper_scale, y1 = p1.Y / clipper_scale, x2 = p2.X / clipper_scale, y2 = p2.Y / clipper_scale; - double dist = sqrt(pow(x2-x1, 2) + pow(y2-y1, 2)); - dbg_total_len += dist; - - if (dist < dash_remaining) { - /* dash extends beyond this segment, append this segment and continue. */ - dash_remaining -= dist; - current_dash.push_back(p2); - - } else { - /* dash started in some previous segment ends in this segment */ - double dash_frac = dash_remaining/dist; - double x = x1 + (x2 - x1) * dash_frac, - y = y1 + (y2 - y1) * dash_frac; - ClipperLib::IntPoint intermediate {(ClipperLib::cInt)round(x * clipper_scale), (ClipperLib::cInt)round(y * clipper_scale)}; - - /* end this dash */ - current_dash.push_back(intermediate); - if (dash_idx%2 == 0) { /* dash */ - out.push_back(current_dash); - } /* else space */ - dash_idx = (dash_idx + 1) % num_dashes; - double offset = dash_remaining; - - /* start next dash */ - current_dash.clear(); - current_dash.push_back(intermediate); - - /* handle case where multiple dashes fit into this segment */ - while ((dist - offset) > dasharray[dash_idx]) { - offset += dasharray[dash_idx]; - - double dash_frac = offset/dist; - double x = x1 + (x2 - x1) * dash_frac, - y = y1 + (y2 - y1) * dash_frac; - ClipperLib::IntPoint intermediate {(ClipperLib::cInt)round(x * clipper_scale), (ClipperLib::cInt)round(y * clipper_scale)}; - - /* end this dash */ - current_dash.push_back(intermediate); - if (dash_idx%2 == 0) { /* dash */ - out.push_back(current_dash); - } /* else space */ - dash_idx = (dash_idx + 1) % num_dashes; - - /* start next dash */ - current_dash.clear(); - current_dash.push_back(intermediate); - } - - dash_remaining = dasharray[dash_idx] - (dist - offset); - current_dash.push_back(p2); - } - } -} - |