engine/assets/shaders/bloom_upsample.glsl
2024-03-05 19:29:27 +04:00

58 lines
1.6 KiB
GLSL

// Input, output blocks
VERTEX_EXPORT VertexData {
vec2 uv;
} VertexOut;
#if VERTEX_SHADER
layout(location = 0) in vec3 aPos;
void main() {
gl_Position = vec4(aPos, 1);
VertexOut.uv = aPos.xy * 0.5 + 0.5;
}
#endif // VERTEX_SHADER
#if FRAGMENT_SHADER
layout(binding = 0) uniform sampler2D src_sampler;
layout(location = 19) uniform int src_mip_level;
layout(location = 20) uniform float bloom_strength = 1;
layout(location = 0) out vec3 upsample;
void main() {
vec2 uv = VertexOut.uv;
// Take 9 samples around current texel:
// a - b - c
// d - e - f
// g - h - i
// === ('e' is the current texel) ===
vec3 a = textureLodOffset(src_sampler, uv, src_mip_level, ivec2(-1, 1)).rgb;
vec3 b = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 0, 1)).rgb;
vec3 c = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 1, 1)).rgb;
vec3 d = textureLodOffset(src_sampler, uv, src_mip_level, ivec2(-1, 0)).rgb;
vec3 e = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 0, 0)).rgb;
vec3 f = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 1, 0)).rgb;
vec3 g = textureLodOffset(src_sampler, uv, src_mip_level, ivec2(-1,-1)).rgb;
vec3 h = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 0,-1)).rgb;
vec3 i = textureLodOffset(src_sampler, uv, src_mip_level, ivec2( 1,-1)).rgb;
// Apply weighted distribution, by using a 3x3 tent filter:
// 1 | 1 2 1 |
// -- * | 2 4 2 |
// 16 | 1 2 1 |
upsample = e*4.0;
upsample += (b+d+f+h)*2.0;
upsample += (a+c+g+i);
upsample *= 1.0 / 16.0;
upsample *= bloom_strength;
}
#endif // FRAGMNET_SHADER