90 lines
2.8 KiB
C++
90 lines
2.8 KiB
C++
|
|
#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();
|
|
}
|
|
|
|
}
|