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fgdata/Shaders/HDR/postprocess.frag
2021-07-31 19:13:19 +02:00

83 lines
1.9 KiB
GLSL

#version 330 core
out vec4 fragColor;
in vec2 texCoord;
uniform sampler2D hdr_tex;
uniform sampler2D lum_tex;
uniform sampler2D bloom_tex;
uniform vec2 fg_BufferSize;
uniform float bloom_magnitude;
uniform bool debug_ev100;
vec3 applyExposure(vec3 color, float avgLuminance, float threshold);
vec3 getDebugColor(float value)
{
float level = value*3.14159265/2.0;
vec3 col;
col.r = sin(level);
col.g = sin(level*2.0);
col.b = cos(level);
return col;
}
vec3 debugEV100(vec3 hdr, float avgLuminance)
{
float level;
if (texCoord.y < 0.05) {
const float w = 0.001;
if (texCoord.x >= (0.5 - w) && texCoord.x <= (0.5 + w))
return vec3(1.0);
return getDebugColor(texCoord.x);
}
float luminance = max(dot(hdr, vec3(0.299, 0.587, 0.114)), 0.0001);
float ev100 = log2(luminance * 8.0);
float norm = ev100 / 12.0 + 0.5;
return getDebugColor(norm);
}
const float a = 2.51;
const float b = 0.03;
const float c = 2.43;
const float d = 0.59;
const float e = 0.14;
vec3 ACESFilm(vec3 x)
{
return clamp((x*(a*x+b))/(x*(c*x+d)+e), 0.0, 1.0);
}
vec3 encodeSRGB(vec3 linearRGB)
{
vec3 a = 12.92 * linearRGB;
vec3 b = 1.055 * pow(linearRGB, vec3(1.0 / 2.4)) - 0.055;
vec3 c = step(vec3(0.0031308), linearRGB);
return mix(a, b, c);
}
void main()
{
vec3 hdrColor = texture(hdr_tex, texCoord).rgb;
float avgLuminance = texelFetch(lum_tex, ivec2(0), 0).r;
// Exposure
vec3 exposedHdrColor = applyExposure(hdrColor, avgLuminance, 0.0);
if (debug_ev100) {
fragColor = vec4(debugEV100(exposedHdrColor, avgLuminance), 1.0);
return;
}
// Tonemap
vec3 color = ACESFilm(exposedHdrColor);
// Gamma correction
color = encodeSRGB(color);
// Bloom
vec3 bloom = texture(bloom_tex, texCoord).rgb;
color += bloom.rgb * bloom_magnitude;
fragColor = vec4(color, 1.0);
}