Variable getPCFBaseShadowContributionConst
getPCFBaseShadowContribution: "\nfn getPCFBaseShadowContribution(\n shadowCoords: vec3f,\n pcfSamples: i32,\n bias: f32,\n intensity: f32,\n depthTexture: texture_depth_2d\n) -> f32 {\n var visibility = 0.0;\n \n let inFrustum: bool = shadowCoords.x >= 0.0 && shadowCoords.x <= 1.0 && shadowCoords.y >= 0.0 && shadowCoords.y <= 1.0;\n let frustumTest: bool = inFrustum && shadowCoords.z <= 1.0;\n \n if(frustumTest) {\n // Percentage-closer filtering. Sample texels in the region\n // to smooth the result.\n let size: vec2f = vec2f(textureDimensions(depthTexture).xy);\n \n let texelSize: vec2f = 1.0 / size;\n \n let sampleCount: i32 = pcfSamples;\n let maxSamples: f32 = f32(sampleCount) - 1.0;\n \n for (var x = 0; x < sampleCount; x++) {\n for (var y = 0; y < sampleCount; y++) {\n let offset = texelSize * vec2(\n f32(x) - maxSamples * 0.5,\n f32(y) - maxSamples * 0.5\n );\n \n visibility += textureSampleCompareLevel(\n depthTexture,\n depthComparisonSampler,\n shadowCoords.xy + offset,\n shadowCoords.z - bias\n );\n }\n }\n visibility /= f32(sampleCount * sampleCount);\n \n visibility = mix(1.0, visibility, saturate(intensity));\n }\n else {\n visibility = 1.0;\n }\n \n return visibility;\n}\n" = ...
Helper chunk to compute the shadow visibility of a fragment using
shadowCoords, a 2DdepthTextureand shadow properties using PCF. Returns1when fully visible and0when fully shadowed.