Prototype flattener/compositor code

src/out_flattener.cpp

@@ -0,0 +1,103 @@
+/*
+ * 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 <clipper.hpp>
+#include <gerbolyze.hpp>
+#include <svg_import_defs.h>
+#include <svg_geom.h>
+
+using namespace gerbolyze;
+using namespace std;
+
+namespace gerbolyze {
+    class Flattener_D {
+    public:
+        ClipperLib::Clipper c;
+    };
+}
+
+Flattener::Flattener(PolygonSink &sink) : m_sink(sink) {
+    d = new Flattener_D();
+    d->c.StrictlySimple(true);
+}
+
+Flattener::~Flattener() {
+    delete d;
+}
+
+void Flattener::header(d2p origin, d2p size) {
+    m_sink.header(origin, size);
+}
+
+Flattener &Flattener::operator<<(GerberPolarityToken pol) {
+    if (m_current_polarity != pol) {
+        m_current_polarity = pol;
+    }
+
+    return *this;
+}
+
+Flattener &Flattener::operator<<(const Polygon &poly) {
+    ClipperLib::Path le_path;
+    for (auto &p : poly) {
+        le_path.push_back({(ClipperLib::cInt)round(p[0] * clipper_scale), (ClipperLib::cInt)round(p[1] * clipper_scale)});
+    }
+
+    ClipperLib::Paths out;
+
+    if (m_current_polarity == GRB_POL_DARK) {
+        d->c.AddPath(le_path, ClipperLib::ptSubject, true);
+        d->c.Execute(ClipperLib::ctUnion, out, ClipperLib::pftNonZero);
+
+    } else { /* clear */
+        d->c.AddPath(le_path, ClipperLib::ptClip, true);
+        d->c.Execute(ClipperLib::ctDifference, out, ClipperLib::pftNonZero);
+    }
+
+    d->c.Clear();
+    d->c.AddPaths(out, ClipperLib::ptSubject, true);
+
+    return *this;
+}
+
+void Flattener::footer() {
+    ClipperLib::PolyTree t_out;
+    d->c.Execute(ClipperLib::ctDifference, t_out, ClipperLib::pftNonZero);
+    d->c.Clear();
+
+    m_sink << GRB_POL_DARK;
+
+    ClipperLib::Paths out;
+    cerr << "deholing" << endl;
+    dehole_polytree(t_out, out);
+    for (auto &poly : out) {
+        Polygon poly_out;
+        for (auto &p : poly) {
+            poly_out.push_back({p.X / clipper_scale, p.Y / clipper_scale});
+        }
+        m_sink << poly_out;
+    }
+
+    m_sink.footer();
+}
+