render/vulkan: Unify pre-multiplied alpha handling in output shader

This commit is contained in:
Alexander Orzechowski 2024-08-24 15:56:47 -04:00
parent 3187479c07
commit d9345f4d9c

View file

@ -23,38 +23,28 @@ float linear_channel_to_srgb(float x) {
return max(min(x * 12.92, 0.04045), 1.055 * pow(x, 1. / 2.4) - 0.055);
}
vec4 linear_color_to_srgb(vec4 color) {
if (color.a == 0) {
return vec4(0);
}
color.rgb /= color.a;
color.rgb = vec3(
linear_channel_to_srgb(color.r),
linear_channel_to_srgb(color.g),
linear_channel_to_srgb(color.b)
);
color.rgb *= color.a;
return color;
}
void main() {
vec4 val = subpassLoad(in_color).rgba;
if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_LUT_3D) {
if (val.a == 0) {
out_color = vec4(0);
return;
}
// Convert from pre-multiplied alpha to straight alpha
vec3 rgb = val.rgb / val.a;
if (val.a == 0) {
out_color = vec4(0);
return;
}
// Convert from pre-multiplied alpha to straight alpha
vec3 rgb = val.rgb / val.a;
if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_LUT_3D) {
// Apply 3D LUT
vec3 pos = data.lut_3d_offset + rgb * data.lut_3d_scale;
rgb = texture(lut_3d, pos).rgb;
// Back to pre-multiplied alpha
out_color = vec4(rgb * val.a, val.a);
} else { // OUTPUT_TRANSFORM_INVERSE_SRGB
// Produce post-premultiplied sRGB encoded values
out_color = linear_color_to_srgb(val);
rgb = vec3(
linear_channel_to_srgb(rgb.r),
linear_channel_to_srgb(rgb.g),
linear_channel_to_srgb(rgb.b)
);
}
// Back to pre-multiplied alpha
out_color = vec4(rgb * val.a, val.a);
}