1
2#include "rasterization.h"
3
4#include <vector>
5#include "arithmetics.hpp"
6
7namespace msdfgen {
8
9void rasterize(const BitmapRef<float, 1> &output, const Shape &shape, const Projection &projection, FillRule fillRule) {
10 Scanline scanline;
11 for (int y = 0; y < output.height; ++y) {
12 int row = shape.inverseYAxis ? output.height-y-1 : y;
13 shape.scanline(scanline, projection.unprojectY(y+.5));
14 for (int x = 0; x < output.width; ++x)
15 *output(x, row) = (float) scanline.filled(projection.unprojectX(x+.5), fillRule);
16 }
17}
18
19void distanceSignCorrection(const BitmapRef<float, 1> &sdf, const Shape &shape, const Projection &projection, FillRule fillRule) {
20 Scanline scanline;
21 for (int y = 0; y < sdf.height; ++y) {
22 int row = shape.inverseYAxis ? sdf.height-y-1 : y;
23 shape.scanline(scanline, projection.unprojectY(y+.5));
24 for (int x = 0; x < sdf.width; ++x) {
25 bool fill = scanline.filled(projection.unprojectX(x+.5), fillRule);
26 float &sd = *sdf(x, row);
27 if ((sd > .5f) != fill)
28 sd = 1.f-sd;
29 }
30 }
31}
32
33template <int N>
34static void multiDistanceSignCorrection(const BitmapRef<float, N> &sdf, const Shape &shape, const Projection &projection, FillRule fillRule) {
35 int w = sdf.width, h = sdf.height;
36 if (!(w*h))
37 return;
38 Scanline scanline;
39 bool ambiguous = false;
40 std::vector<char> matchMap;
41 matchMap.resize(w*h);
42 char *match = &matchMap[0];
43 for (int y = 0; y < h; ++y) {
44 int row = shape.inverseYAxis ? h-y-1 : y;
45 shape.scanline(scanline, projection.unprojectY(y+.5));
46 for (int x = 0; x < w; ++x) {
47 bool fill = scanline.filled(projection.unprojectX(x+.5), fillRule);
48 float *msd = sdf(x, row);
49 float sd = median(msd[0], msd[1], msd[2]);
50 if (sd == .5f)
51 ambiguous = true;
52 else if ((sd > .5f) != fill) {
53 msd[0] = 1.f-msd[0];
54 msd[1] = 1.f-msd[1];
55 msd[2] = 1.f-msd[2];
56 *match = -1;
57 } else
58 *match = 1;
59 if (N >= 4 && (msd[3] > .5f) != fill)
60 msd[3] = 1.f-msd[3];
61 ++match;
62 }
63 }
64 // This step is necessary to avoid artifacts when whole shape is inverted
65 if (ambiguous) {
66 match = &matchMap[0];
67 for (int y = 0; y < h; ++y) {
68 int row = shape.inverseYAxis ? h-y-1 : y;
69 for (int x = 0; x < w; ++x) {
70 if (!*match) {
71 int neighborMatch = 0;
72 if (x > 0) neighborMatch += *(match-1);
73 if (x < w-1) neighborMatch += *(match+1);
74 if (y > 0) neighborMatch += *(match-w);
75 if (y < h-1) neighborMatch += *(match+w);
76 if (neighborMatch < 0) {
77 float *msd = sdf(x, row);
78 msd[0] = 1.f-msd[0];
79 msd[1] = 1.f-msd[1];
80 msd[2] = 1.f-msd[2];
81 }
82 }
83 ++match;
84 }
85 }
86 }
87}
88
89void distanceSignCorrection(const BitmapRef<float, 3> &sdf, const Shape &shape, const Projection &projection, FillRule fillRule) {
90 multiDistanceSignCorrection(sdf, shape, projection, fillRule);
91}
92
93void distanceSignCorrection(const BitmapRef<float, 4> &sdf, const Shape &shape, const Projection &projection, FillRule fillRule) {
94 multiDistanceSignCorrection(sdf, shape, projection, fillRule);
95}
96
97// Legacy API
98
99void rasterize(const BitmapRef<float, 1> &output, const Shape &shape, const Vector2 &scale, const Vector2 &translate, FillRule fillRule) {
100 rasterize(output, shape, Projection(scale, translate), fillRule);
101}
102
103void distanceSignCorrection(const BitmapRef<float, 1> &sdf, const Shape &shape, const Vector2 &scale, const Vector2 &translate, FillRule fillRule) {
104 distanceSignCorrection(sdf, shape, Projection(scale, translate), fillRule);
105}
106
107void distanceSignCorrection(const BitmapRef<float, 3> &sdf, const Shape &shape, const Vector2 &scale, const Vector2 &translate, FillRule fillRule) {
108 distanceSignCorrection(sdf, shape, Projection(scale, translate), fillRule);
109}
110
111void distanceSignCorrection(const BitmapRef<float, 4> &sdf, const Shape &shape, const Vector2 &scale, const Vector2 &translate, FillRule fillRule) {
112 distanceSignCorrection(sdf, shape, Projection(scale, translate), fillRule);
113}
114
115}
116