Files
basis_universal/python/shader_deblocking/shader.glsl
Richard Geldreich e5aa8306f3 adding new sample
2026-07-01 13:15:57 -04:00

99 lines
3.4 KiB
GLSL

#vertex
#version 330 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec2 aUV;
uniform mat4 mvp;
out vec2 vUV;
void main() {
vUV = aUV;
gl_Position = mvp * vec4(aPos, 1.0);
}
#fragment
#version 330 core
uniform sampler2D tex;
uniform vec4 texSize; // Base mip dimensions (mip 0) in xy, zw=ASTC block size of texture
uniform float maxLod; // = number_of_mip_levels - 1
uniform vec4 const0; // User constant 0 (keys 1-4 toggle x,y,z,w)
uniform vec4 const1; // User constant 1 (keys 5-8 toggle x,y,z,w)
in vec2 vUV;
out vec4 fragColor;
void main()
{
// Note: Could use textureQueryLod() but it's not supported in WebGL. textureSize() is in WebGL 2.0 however.
const vec3 LUMA = vec3(0.299, 0.587, 0.114);
vec2 texDim = vec2(texSize.x, texSize.y);
vec2 blockSize = vec2(texSize.z, texSize.w);
vec2 du = dFdx(vUV);
vec2 dv = dFdy(vUV);
float rho = max(length(du * texSize.xy), length(dv * texSize.xy));
float lod = clamp(log2(max(rho, 1e-8)), 0.0, maxLod); // lod index
float mipScale = exp2(floor(lod + .5)); // 2^lod mipmap scale, snaps to dominant mipmap, 1=mip0, 2=mip1, 4=mip2, etc.
vec2 texelStep = mipScale / texDim; // how to step one texel in effective mip space
vec2 texelPos = (vUV * texDim) / mipScale; // the physical texel coord in effective mip space
vec2 blockPos = mod(texelPos, blockSize); // the block offset in texels
vec3 color;
color = texture(tex, vUV).rgb;
// Keep these fetches outside non-uniform control flow: texture() uses implicit
// derivatives for LOD, which are undefined when neighboring fragments take
// different branches. Use explicit LOD so edgeWeight can safely go to zero.
vec3 l1 = texture(tex, vUV - vec2(texelStep.x, 0.0)).rgb;
vec3 r1 = texture(tex, vUV + vec2(texelStep.x, 0.0)).rgb;
vec3 u1 = texture(tex, vUV - vec2(0.0, texelStep.y)).rgb;
vec3 d1 = texture(tex, vUV + vec2(0.0, texelStep.y)).rgb;
if (const0.x > 0.5)
{
const float falloff = 1.5;
float leftProx = 1.0 - clamp(blockPos.x / falloff, 0.0, 1.0);
float rightProx = 1.0 - clamp((blockSize.x - blockPos.x) / falloff, 0.0, 1.0);
float topProx = 1.0 - clamp(blockPos.y / falloff, 0.0, 1.0);
float bottomProx = 1.0 - clamp((blockSize.y - blockPos.y) / falloff, 0.0, 1.0);
float horizWeight = max(leftProx, rightProx);
float vertWeight = max(topProx, bottomProx);
float edgeWeight = max(horizWeight, vertWeight); // overall proximity
if (edgeWeight > 0.0)
{
vec3 c0 = color;
vec3 filteredH = (l1 + c0 + r1) * (1.0/3.0);
vec3 filteredV = (u1 + c0 + d1) * (1.0/3.0);
float strengthH = horizWeight;
float strengthV = vertWeight;
vec3 horizColor = mix(c0, filteredH, strengthH);
vec3 vertColor = mix(c0, filteredV, strengthV);
float totalW = strengthH + strengthV;
if (totalW > 0.0)
color = (horizColor * strengthH + vertColor * strengthV) / totalW;
}
// block edge vis
if (const0.y > 0.5)
{
color = vec3(edgeWeight, edgeWeight, edgeWeight);
}
}
fragColor = vec4(color, 1.0);
}