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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
#[compute]
#version 450
#VERSION_DEFINES
layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
layout(r8, set = 0, binding = 1) uniform restrict readonly image2D src_pixels;
layout(r16_snorm, set = 0, binding = 2) uniform restrict writeonly image2D dst_sdf;
layout(rg16i, set = 0, binding = 3) uniform restrict readonly iimage2D src_process;
layout(rg16i, set = 0, binding = 4) uniform restrict writeonly iimage2D dst_process;
layout(push_constant, binding = 0, std430) uniform Params {
ivec2 size;
int stride;
int shift;
ivec2 base_size;
uvec2 pad;
}
params;
#define SDF_MAX_LENGTH 16384.0
void main() {
ivec2 pos = ivec2(gl_GlobalInvocationID.xy);
if (any(greaterThanEqual(pos, params.size))) { //too large, do nothing
return;
}
#ifdef MODE_LOAD
bool solid = imageLoad(src_pixels, pos).r > 0.5;
imageStore(dst_process, pos, solid ? ivec4(ivec2(-32767), 0, 0) : ivec4(ivec2(32767), 0, 0));
#endif
#ifdef MODE_LOAD_SHRINK
int s = 1 << params.shift;
ivec2 base = pos << params.shift;
ivec2 center = base + ivec2(params.shift);
ivec2 rel = ivec2(32767);
float d = 1e20;
int found = 0;
int solid_found = 0;
for (int i = 0; i < s; i++) {
for (int j = 0; j < s; j++) {
ivec2 src_pos = base + ivec2(i, j);
if (any(greaterThanEqual(src_pos, params.base_size))) {
continue;
}
bool solid = imageLoad(src_pixels, src_pos).r > 0.5;
if (solid) {
float dist = length(vec2(src_pos - center));
if (dist < d) {
d = dist;
rel = src_pos;
}
solid_found++;
}
found++;
}
}
if (solid_found == found) {
//mark solid only if all are solid
rel = ivec2(-32767);
}
imageStore(dst_process, pos, ivec4(rel, 0, 0));
#endif
#ifdef MODE_PROCESS
ivec2 base = pos << params.shift;
ivec2 center = base + ivec2(params.shift);
ivec2 rel = imageLoad(src_process, pos).xy;
bool solid = rel.x < 0;
if (solid) {
rel = -rel - ivec2(1);
}
if (center != rel) {
//only process if it does not point to itself
const int ofs_table_size = 8;
const ivec2 ofs_table[ofs_table_size] = ivec2[](
ivec2(-1, -1),
ivec2(0, -1),
ivec2(+1, -1),
ivec2(-1, 0),
ivec2(+1, 0),
ivec2(-1, +1),
ivec2(0, +1),
ivec2(+1, +1));
float dist = length(vec2(rel - center));
for (int i = 0; i < ofs_table_size; i++) {
ivec2 src_pos = pos + ofs_table[i] * params.stride;
if (any(lessThan(src_pos, ivec2(0))) || any(greaterThanEqual(src_pos, params.size))) {
continue;
}
ivec2 src_rel = imageLoad(src_process, src_pos).xy;
bool src_solid = src_rel.x < 0;
if (src_solid) {
src_rel = -src_rel - ivec2(1);
}
if (src_solid != solid) {
src_rel = ivec2(src_pos << params.shift); //point to itself if of different type
}
float src_dist = length(vec2(src_rel - center));
if (src_dist < dist) {
dist = src_dist;
rel = src_rel;
}
}
}
if (solid) {
rel = -rel - ivec2(1);
}
imageStore(dst_process, pos, ivec4(rel, 0, 0));
#endif
#ifdef MODE_STORE
ivec2 rel = imageLoad(src_process, pos).xy;
bool solid = rel.x < 0;
if (solid) {
rel = -rel - ivec2(1);
}
float d = length(vec2(rel - pos));
if (solid) {
d = -d;
}
d /= SDF_MAX_LENGTH;
d = clamp(d, -1.0, 1.0);
imageStore(dst_sdf, pos, vec4(d));
#endif
#ifdef MODE_STORE_SHRINK
ivec2 base = pos << params.shift;
ivec2 center = base + ivec2(params.shift);
ivec2 rel = imageLoad(src_process, pos).xy;
bool solid = rel.x < 0;
if (solid) {
rel = -rel - ivec2(1);
}
float d = length(vec2(rel - center));
if (solid) {
d = -d;
}
d /= SDF_MAX_LENGTH;
d = clamp(d, -1.0, 1.0);
imageStore(dst_sdf, pos, vec4(d));
#endif
}
|