wlroots/render/vulkan/shaders/output.frag

92 lines
2.5 KiB
GLSL

#version 450
layout (input_attachment_index = 0, set = 0, binding = 0) uniform subpassInput in_color;
layout(set = 1, binding = 0) uniform sampler3D lut_3d;
layout(location = 0) in vec2 uv;
layout(location = 0) out vec4 out_color;
/* struct wlr_vk_frag_output_pcr_data */
layout(push_constant, row_major) uniform UBO {
layout(offset = 80) mat4 matrix;
float luminance_multiplier;
float lut_3d_offset;
float lut_3d_scale;
} data;
layout (constant_id = 0) const int OUTPUT_TRANSFORM = 0;
// Matches enum wlr_vk_output_transform
#define OUTPUT_TRANSFORM_IDENTITY 0
#define OUTPUT_TRANSFORM_INVERSE_SRGB 1
#define OUTPUT_TRANSFORM_INVERSE_ST2084_PQ 2
#define OUTPUT_TRANSFORM_LUT_3D 3
#define OUTPUT_TRANSFORM_INVERSE_GAMMA22 4
#define OUTPUT_TRANSFORM_INVERSE_BT1886 5
float linear_channel_to_srgb(float x) {
return max(min(x * 12.92, 0.04045), 1.055 * pow(x, 1. / 2.4) - 0.055);
}
vec3 linear_color_to_srgb(vec3 color) {
return vec3(
linear_channel_to_srgb(color.r),
linear_channel_to_srgb(color.g),
linear_channel_to_srgb(color.b)
);
}
vec3 linear_color_to_pq(vec3 color) {
// H.273 TransferCharacteristics code point 16
float c1 = 0.8359375;
float c2 = 18.8515625;
float c3 = 18.6875;
float m = 78.84375;
float n = 0.1593017578125;
vec3 pow_n = pow(clamp(color, vec3(0), vec3(1)), vec3(n));
return pow((vec3(c1) + c2 * pow_n) / (vec3(1) + c3 * pow_n), vec3(m));
}
vec3 linear_color_to_bt1886(vec3 color) {
float lb = pow(0.0001, 1.0 / 2.4);
float lw = pow(1.0, 1.0 / 2.4);
float a = pow(lw - lb, 2.4);
float b = lb / (lw - lb);
return pow(color / a, vec3(1.0 / 2.4)) - vec3(b);
}
void main() {
vec4 in_color = subpassLoad(in_color).rgba;
// Convert from pre-multiplied alpha to straight alpha
float alpha = in_color.a;
vec3 rgb;
if (alpha == 0) {
rgb = vec3(0);
} else {
rgb = in_color.rgb / alpha;
}
rgb *= data.luminance_multiplier;
rgb = mat3(data.matrix) * rgb;
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;
} else if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_INVERSE_ST2084_PQ) {
rgb = linear_color_to_pq(rgb);
} else if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_INVERSE_SRGB) {
// Produce sRGB encoded values
rgb = linear_color_to_srgb(rgb);
} else if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_INVERSE_GAMMA22) {
rgb = pow(rgb, vec3(1. / 2.2));
} else if (OUTPUT_TRANSFORM == OUTPUT_TRANSFORM_INVERSE_BT1886) {
rgb = linear_color_to_bt1886(rgb);
}
// Back to pre-multiplied alpha
out_color = vec4(rgb * alpha, alpha);
}