initial commit, 4.5 stable

thirdparty/msdfgen/core/Contour.cpp

@@ -0,0 +1,90 @@
+
+#include "Contour.h"
+
+#include "arithmetics.hpp"
+
+namespace msdfgen {
+
+static double shoelace(const Point2 &a, const Point2 &b) {
+    return (b.x-a.x)*(a.y+b.y);
+}
+
+void Contour::addEdge(const EdgeHolder &edge) {
+    edges.push_back(edge);
+}
+
+#ifdef MSDFGEN_USE_CPP11
+void Contour::addEdge(EdgeHolder &&edge) {
+    edges.push_back((EdgeHolder &&) edge);
+}
+#endif
+
+EdgeHolder &Contour::addEdge() {
+    edges.resize(edges.size()+1);
+    return edges.back();
+}
+
+static void boundPoint(double &l, double &b, double &r, double &t, Point2 p) {
+    if (p.x < l) l = p.x;
+    if (p.y < b) b = p.y;
+    if (p.x > r) r = p.x;
+    if (p.y > t) t = p.y;
+}
+
+void Contour::bound(double &l, double &b, double &r, double &t) const {
+    for (std::vector<EdgeHolder>::const_iterator edge = edges.begin(); edge != edges.end(); ++edge)
+        (*edge)->bound(l, b, r, t);
+}
+
+void Contour::boundMiters(double &l, double &b, double &r, double &t, double border, double miterLimit, int polarity) const {
+    if (edges.empty())
+        return;
+    Vector2 prevDir = edges.back()->direction(1).normalize(true);
+    for (std::vector<EdgeHolder>::const_iterator edge = edges.begin(); edge != edges.end(); ++edge) {
+        Vector2 dir = -(*edge)->direction(0).normalize(true);
+        if (polarity*crossProduct(prevDir, dir) >= 0) {
+            double miterLength = miterLimit;
+            double q = .5*(1-dotProduct(prevDir, dir));
+            if (q > 0)
+                miterLength = min(1/sqrt(q), miterLimit);
+            Point2 miter = (*edge)->point(0)+border*miterLength*(prevDir+dir).normalize(true);
+            boundPoint(l, b, r, t, miter);
+        }
+        prevDir = (*edge)->direction(1).normalize(true);
+    }
+}
+
+int Contour::winding() const {
+    if (edges.empty())
+        return 0;
+    double total = 0;
+    if (edges.size() == 1) {
+        Point2 a = edges[0]->point(0), b = edges[0]->point(1/3.), c = edges[0]->point(2/3.);
+        total += shoelace(a, b);
+        total += shoelace(b, c);
+        total += shoelace(c, a);
+    } else if (edges.size() == 2) {
+        Point2 a = edges[0]->point(0), b = edges[0]->point(.5), c = edges[1]->point(0), d = edges[1]->point(.5);
+        total += shoelace(a, b);
+        total += shoelace(b, c);
+        total += shoelace(c, d);
+        total += shoelace(d, a);
+    } else {
+        Point2 prev = edges.back()->point(0);
+        for (std::vector<EdgeHolder>::const_iterator edge = edges.begin(); edge != edges.end(); ++edge) {
+            Point2 cur = (*edge)->point(0);
+            total += shoelace(prev, cur);
+            prev = cur;
+        }
+    }
+    return sign(total);
+}
+
+void Contour::reverse() {
+    for (int i = (int) edges.size()/2; i > 0; --i)
+        EdgeHolder::swap(edges[i-1], edges[edges.size()-i]);
+    for (std::vector<EdgeHolder>::iterator edge = edges.begin(); edge != edges.end(); ++edge)
+        (*edge)->reverse();
+}
+
+}