Terrain4J_Experimental_branch/resources/EngineResources/shaders/post_process_frag.glsl
2026-09-25 23:37:22 +01:00

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3.3 KiB
GLSL

#version 450
layout(constant_id = 0) const int USE_AA = 0;
const float SPAN_MAX = 8.0;
const float REDUCE_MIN = 1.0/128.0;
const float REDUCE_MUL = 1.0/32.0;
layout(location = 0) in vec2 inTextCoord;
layout(location = 0) out vec4 outFragColor;
layout(set = 0, binding = 0) uniform sampler2D inputTexture;
layout(set = 0, binding = 1) uniform sampler2D bloomImage;
layout(push_constant) uniform PassConfig {
int horizontal;
float GAMMA_CONST;
float Exposure;
float blur_radius;
vec2 bloomSize;
} config;
// Sourced from: https://mini.gmshaders.com/p/gm-shaders-mini-fxaa
vec4 fxaa(sampler2D tex, vec2 uv) {
vec2 u_texel = 1.0 / vec2(textureSize(inputTexture, 0));
//Sample center and 4 corners
vec3 rgbCC = texture(tex, uv).rgb;
vec3 rgb00 = texture(tex, uv+vec2(-0.5,-0.5)*u_texel).rgb;
vec3 rgb10 = texture(tex, uv+vec2(+0.5,-0.5)*u_texel).rgb;
vec3 rgb01 = texture(tex, uv+vec2(-0.5,+0.5)*u_texel).rgb;
vec3 rgb11 = texture(tex, uv+vec2(+0.5,+0.5)*u_texel).rgb;
//Luma coefficients
const vec3 luma = vec3(0.299, 0.587, 0.114);
//Get luma from the 5 samples
float lumaCC = dot(rgbCC, luma);
float luma00 = dot(rgb00, luma);
float luma10 = dot(rgb10, luma);
float luma01 = dot(rgb01, luma);
float luma11 = dot(rgb11, luma);
//Compute gradient from luma values
vec2 dir = vec2((luma01 + luma11) - (luma00 + luma10), (luma00 + luma01) - (luma10 + luma11));
//Diminish dir length based on total luma
float dirReduce = max((luma00 + luma10 + luma01 + luma11) * REDUCE_MUL, REDUCE_MIN);
//Divide dir by the distance to nearest edge plus dirReduce
float rcpDir = 1.0 / (min(abs(dir.x), abs(dir.y)) + dirReduce);
//Multiply by reciprocal and limit to pixel span
dir = clamp(dir * rcpDir, -SPAN_MAX, SPAN_MAX) * u_texel.xy;
//Average middle texels along dir line
vec4 A = 0.5 * (
texture(tex, uv - dir * (1.0/6.0)) +
texture(tex, uv + dir * (1.0/6.0)));
//Average with outer texels along dir line
vec4 B = A * 0.5 + 0.25 * (
texture(tex, uv - dir * (0.5)) +
texture(tex, uv + dir * (0.5)));
//Get lowest and highest luma values
float lumaMin = min(lumaCC, min(min(luma00, luma10), min(luma01, luma11)));
float lumaMax = max(lumaCC, max(max(luma00, luma10), max(luma01, luma11)));
//Get average luma
float lumaB = dot(B.rgb, luma);
//If the average is outside the luma range, using the middle average
return ((lumaB < lumaMin) || (lumaB > lumaMax)) ? A : B;
}
vec3 bloomAt(ivec2 pixel, ivec2 size) {
return texelFetch(bloomImage, clamp(pixel, ivec2(0), size - 1), 0).rgb;
}
vec3 upsampleBloom(vec2 uv) {
ivec2 size = textureSize(bloomImage, 0);
vec2 pixel = uv * vec2(size) - 0.5;
ivec2 base = ivec2(floor(pixel));
vec2 blend = fract(pixel);
return mix(mix(bloomAt(base, size), bloomAt(base + ivec2(1, 0), size), blend.x),
mix(bloomAt(base + ivec2(0, 1), size), bloomAt(base + ivec2(1, 1), size), blend.x), blend.y);
}
void main(){
vec4 sceneColor = USE_AA == 1 ? fxaa(inputTexture, inTextCoord) : texture(inputTexture, inTextCoord);
vec3 hdrColour = max(sceneColor.rgb + upsampleBloom(inTextCoord), vec3(0.0));
vec3 result = vec3(1.0) - exp(-hdrColour * config.Exposure);
outFragColor = vec4(pow(result, vec3(1.0 / config.GAMMA_CONST)), sceneColor.a);
}