Add dilation option

src/out_dilater.cpp

@@ -0,0 +1,90 @@
+/*
+ * 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 <algorithm>
+#include <string>
+#include <iostream>
+#include <iomanip>
+#include <gerbolyze.hpp>
+#include <clipper.hpp>
+#include <svg_import_defs.h>
+#include <svg_geom.h>
+#include "polylinecombine.hpp"
+
+using namespace gerbolyze;
+using namespace std;
+
+void Dilater::header(d2p origin, d2p size) {
+    m_sink.header(origin, size);
+}
+
+void Dilater::footer() {
+    m_sink.footer();
+}
+
+Dilater &Dilater::operator<<(const LayerNameToken &layer_name) {
+    m_sink << layer_name;
+
+    return *this;
+}
+
+Dilater &Dilater::operator<<(GerberPolarityToken pol) {
+    m_current_polarity = pol;
+    m_sink << pol;
+
+    return *this;
+}
+
+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)});
+    }
+
+    ClipperLib::ClipperOffset offx;
+    offx.ArcTolerance = 0.01 * clipper_scale; /* 10µm; TODO: Make this configurable */
+    offx.AddPath(poly_c, ClipperLib::jtRound, ClipperLib::etClosedPolygon);
+    double dilation = m_dilation;
+    if (m_current_polarity == GRB_POL_CLEAR) {
+        dilation = -dilation;
+    }
+
+    ClipperLib::PolyTree solution; 
+    offx.Execute(solution, dilation * clipper_scale);
+
+    ClipperLib::Paths c_nice_polys;
+    dehole_polytree(solution, c_nice_polys);
+
+    for (auto &nice_poly : c_nice_polys) {
+        Polygon new_poly;
+        for (auto &p : nice_poly) {
+            new_poly.push_back({
+                    (double)p.X / clipper_scale,
+                    (double)p.Y / clipper_scale });
+        }
+        m_sink << new_poly;
+    }
+
+    return *this;
+}
+