chore: shader cleanup & tweaks

Author: hoffstadt

shaders/deferred_lighting.frag

@@ -97,195 +97,7 @@ layout(location = 0) in struct plShaderIn {
     vec2 tUV;
 } tShaderIn;
 
-vec3
-getDiffuseLight(vec3 n, int iProbeIndex)
-{
-    // n.z = -n.z; // uncomment if not reverse z
-    // return texture(samplerCube(u_LambertianEnvSampler, tEnvSampler), n).rgb;
-    return texture(samplerCube(atCubeTextures[nonuniformEXT(tProbeData.atData[iProbeIndex].uLambertianEnvSampler)], tEnvSampler), n).rgb;
-}
-
-vec4
-getSpecularSample(vec3 reflection, float lod, int iProbeIndex)
-{
-    // reflection.z = -reflection.z; // uncomment if not reverse z
-    // reflection.x = -reflection.x; // uncomment if not reverse z
-    // return textureLod(samplerCube(u_GGXEnvSampler, tEnvSampler), reflection, lod);
-    return textureLod(samplerCube(atCubeTextures[nonuniformEXT(tProbeData.atData[iProbeIndex].uGGXEnvSampler)], tEnvSampler), reflection, lod);
-}
-
-vec3
-getIBLRadianceGGX(vec3 n, vec3 v, float roughness, vec3 F0, float specularWeight, int u_MipCount, int iProbeIndex, vec3 tWorldPos)
-{
-    
-    float lod = roughness * float(u_MipCount - 1);
-    vec3 reflection = normalize(reflect(-v, n));
-
-    if(bool(tProbeData.atData[iProbeIndex].iParallaxCorrection))
-    {
-
-        // Find the ray intersection with box plane
-        vec3 FirstPlaneIntersect = (tProbeData.atData[iProbeIndex].tMax.xyz - tWorldPos) / reflection;
-        vec3 SecondPlaneIntersect = (tProbeData.atData[iProbeIndex].tMin.xyz - tWorldPos) / reflection;
-        
-        // Get the furthest of these intersections along the ray
-        // (Ok because x/0 give +inf and -x/0 give –inf )
-        vec3 FurthestPlane = max(FirstPlaneIntersect, SecondPlaneIntersect);
-
-        // Find the closest far intersection
-        float Distance = min(min(FurthestPlane.x, FurthestPlane.y), FurthestPlane.z);
-
-        // Get the intersection position
-        vec3 IntersectPositionWS = tWorldPos + reflection * Distance;
-        
-        // Get corrected reflection
-        reflection = IntersectPositionWS - tProbeData.atData[iProbeIndex].tPosition;
-    }
-    
-    // End parallax-correction code
-
-    vec4 specularSample = getSpecularSample(reflection, lod, iProbeIndex);
-
-    float NdotV = clampedDot(n, v);
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    // vec2 f_ab = texture(sampler2D(u_GGXLUT, tEnvSampler), brdfSamplePoint).rg;
-    vec2 f_ab = texture(sampler2D(at2DTextures[nonuniformEXT(tProbeData.atData[iProbeIndex].uGGXLUT)], tEnvSampler), brdfSamplePoint).rg;
-
-    vec3 specularLight = specularSample.rgb;
-
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = k_S * f_ab.x + f_ab.y;
-
-    return specularWeight * specularLight * FssEss;
-}
-
-// specularWeight is introduced with KHR_materials_specular
-vec3
-getIBLRadianceLambertian(vec3 n, vec3 v, float roughness, vec3 diffuseColor, vec3 F0, float specularWeight, int iProbeIndex, vec3 tWorldPos)
-{
-
-    // if(bool(tProbeData.atData[iProbeIndex].iParallaxCorrection))
-    // {
-
-    //     // Find the ray intersection with box plane
-    //     vec3 FirstPlaneIntersect = (tProbeData.atData[iProbeIndex].tMax.xyz - tWorldPos) / n;
-    //     vec3 SecondPlaneIntersect = (tProbeData.atData[iProbeIndex].tMin.xyz - tWorldPos) / n;
-        
-    //     // Get the furthest of these intersections along the ray
-    //     // (Ok because x/0 give +inf and -x/0 give –inf )
-    //     vec3 FurthestPlane = max(FirstPlaneIntersect, SecondPlaneIntersect);
-
-    //     // Find the closest far intersection
-    //     float Distance = min(min(FurthestPlane.x, FurthestPlane.y), FurthestPlane.z);
-
-    //     // Get the intersection position
-    //     vec3 IntersectPositionWS = tWorldPos + n * Distance;
-
-    //     // Get corrected reflection
-    //     n = IntersectPositionWS - tProbeData.atData[iProbeIndex].tPosition;
-    // }
-
-    // End parallax-correction code
-
-    vec3 irradiance = getDiffuseLight(n, iProbeIndex);
-
-    float NdotV = clampedDot(n, v);
-    vec2 brdfSamplePoint = clamp(vec2(NdotV, roughness), vec2(0.0, 0.0), vec2(1.0, 1.0));
-    // vec2 f_ab = texture(sampler2D(u_GGXLUT, tEnvSampler), brdfSamplePoint).rg;
-    vec2 f_ab = texture(sampler2D(at2DTextures[nonuniformEXT(tProbeData.atData[iProbeIndex].uGGXLUT)], tEnvSampler), brdfSamplePoint).rg;
-
-    // see https://bruop.github.io/ibl/#single_scattering_results at Single Scattering Results
-    // Roughness dependent fresnel, from Fdez-Aguera
-
-    vec3 Fr = max(vec3(1.0 - roughness), F0) - F0;
-    vec3 k_S = F0 + Fr * pow(1.0 - NdotV, 5.0);
-    vec3 FssEss = specularWeight * k_S * f_ab.x + f_ab.y; // <--- GGX / specular light contribution (scale it down if the specularWeight is low)
-
-    // Multiple scattering, from Fdez-Aguera
-    float Ems = (1.0 - (f_ab.x + f_ab.y));
-    vec3 F_avg = specularWeight * (F0 + (1.0 - F0) / 21.0);
-    vec3 FmsEms = Ems * FssEss * F_avg / (1.0 - F_avg * Ems);
-    vec3 k_D = diffuseColor * (1.0 - FssEss + FmsEms); // we use +FmsEms as indicated by the formula in the blog post (might be a typo in the implementation)
-
-    return (FmsEms + k_D) * irradiance;
-}
-
-float
-textureProj(vec4 shadowCoord, vec2 offset, int textureIndex)
-{
-	float shadow = 1.0;
-    vec2 comp2 = shadowCoord.st + offset;
-
-	if ( shadowCoord.z > -1.0 && shadowCoord.z < 1.0 )
-    {
-		float dist = 1.0 - texture(sampler2D(at2DTextures[nonuniformEXT(textureIndex)], tShadowSampler), comp2).r * shadowCoord.w;
-		if (shadowCoord.w > 0 && dist < shadowCoord.z)
-        {
-			shadow = 0.0; // ambient
-		}
-	}
-	return shadow;
-}
-
-float
-textureProj2(vec4 shadowCoord, vec2 offset, int textureIndex)
-{
-	float shadow = 1.0;
-    vec2 comp2 = shadowCoord.st + offset;
-
-	if ( shadowCoord.z > -1.0 && shadowCoord.z < 1.0 )
-    {
-		float dist = texture(sampler2D(at2DTextures[nonuniformEXT(textureIndex)], tShadowSampler), comp2).r;
-		if (shadowCoord.w > 0 && dist > shadowCoord.z)
-        {
-			shadow = 0.0; // ambient
-		}
-	}
-	return shadow;
-}
-
-float
-filterPCF(vec4 sc, vec2 offset, int textureIndex)
-{
-	ivec2 texDim = textureSize(sampler2D(at2DTextures[nonuniformEXT(textureIndex)], tShadowSampler), 0).xy;
-	float scale = 1.0;
-	float dx = scale * 1.0 / (float(texDim.x));
-	float dy = scale * 1.0 / (float(texDim.y));
-
-	float shadowFactor = 0.0;
-	int count = 0;
-	int range = 1;
-	
-	for (int x = -range; x <= range; x++) {
-		for (int y = -range; y <= range; y++) {
-			shadowFactor += textureProj(sc, vec2(dx*x, dy*y) + offset, textureIndex);
-			count++;
-		}
-	}
-	return shadowFactor / count;
-}
-
-float
-filterPCF2(vec4 sc, vec2 offset, int textureIndex)
-{
-	ivec2 texDim = textureSize(sampler2D(at2DTextures[nonuniformEXT(textureIndex)], tShadowSampler), 0).xy;
-	float scale = 1.0;
-	float dx = scale * 1.0 / (float(texDim.x));
-	float dy = scale * 1.0 / (float(texDim.y));
-
-	float shadowFactor = 0.0;
-	int count = 0;
-	int range = 1;
-	
-	for (int x = -range; x <= range; x++) {
-		for (int y = -range; y <= range; y++) {
-			shadowFactor += textureProj2(sc, vec2(dx*x, dy*y) + offset, textureIndex);
-			count++;
-		}
-	}
-	return shadowFactor / count;
-}
+#include "lighting.glsl"
 
 void main() 
 {

shaders/filter_environment.comp

@@ -74,27 +74,35 @@ pl_write_face(int iPixel, int iFace, vec3 tColorIn)
         tFaceOut5.atPixelData[iPixel] = tColor;
 }
 
-float
-pl_radical_inverse_vdc(uint uBits)
+vec2
+pl_hammersley_2d(int i, int iN)
 {
     // Hammersley Points on the Hemisphere
     // CC BY 3.0 (Holger Dammertz)
     // http://holger.dammertz.org/stuff/notes_HammersleyOnHemisphere.html
     // with adapted interface
+    uint uBits =  uint(i);
     uBits = (uBits << 16u) | (uBits >> 16u);
     uBits = ((uBits & 0x55555555u) << 1u) | ((uBits & 0xAAAAAAAAu) >> 1u);
     uBits = ((uBits & 0x33333333u) << 2u) | ((uBits & 0xCCCCCCCCu) >> 2u);
     uBits = ((uBits & 0x0F0F0F0Fu) << 4u) | ((uBits & 0xF0F0F0F0u) >> 4u);
     uBits = ((uBits & 0x00FF00FFu) << 8u) | ((uBits & 0xFF00FF00u) >> 8u);
-    return float(uBits) * 2.3283064365386963e-10; // / 0x100000000
-}
+    float rdi = float(uBits) * 2.3283064365386963e-10; // / 0x100000000
 
-vec2
-pl_hammersley_2d(int i, int iN)
-{
     // hammersley2d describes a sequence of points in the 2d unit square [0,1)^2
     // that can be used for quasi Monte Carlo integration
-    return vec2(float(i)/float(iN), pl_radical_inverse_vdc(uint(i)));
+    return vec2(float(i)/float(iN), rdi);
+}
+
+float
+pl_random(vec2 co)
+{
+    float a = 12.9898;
+    float b = 78.233;
+    float c = 43758.5453;
+    float dt = dot(co.xy, vec2(a, b));
+    float sn = mod(dt, 3.14);
+    return fract(sin(sn) * c);
 }
 
 mat3
@@ -243,6 +251,8 @@ pl_get_importance_sample(int iSampleIndex, vec3 tN, float fRoughness)
         tImportanceSample = pl_charlie(tXi, fRoughness);
     }
 
+    tImportanceSample.phi = tImportanceSample.phi + pl_random(tN.xz) * 0.1;
+
     // transform the hemisphere sample to the normal coordinate frame
     // i.e. rotate the hemisphere to the normal direction
     const vec3 tLocalSpaceDirection = normalize(vec3(