1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
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();
}
}
|