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#[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, 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(pos, 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;
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;
}
}
}
}
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;
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;
float src_dist = length(vec2(src_rel - center));
if (src_dist < dist) {
dist = src_dist;
rel = src_rel;
}
}
}
imageStore(dst_process, pos, ivec4(rel, 0, 0));
#endif
#ifdef MODE_STORE
ivec2 rel = imageLoad(src_process, pos).xy;
float d = length(vec2(rel - pos));
if (d > 0.01) {
d += 1.0; //make it signed
}
d /= SDF_MAX_LENGTH;
d = clamp(d, 0.0, 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;
float d = length(vec2(rel - center));
if (d > 0.01) {
d += 1.0; //make it signed
}
d /= SDF_MAX_LENGTH;
d = clamp(d, 0.0, 1.0);
imageStore(dst_sdf, pos, vec4(d));
#endif
}
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