playcanvas
Version:
PlayCanvas WebGL game engine
203 lines (149 loc) • 9.44 kB
JavaScript
// functions used to evaluate the light shadow
var lightFunctionShadowPS = /* wgsl */ `
// shadow casting functionality
// generate shadow coordinates function, based on per light defines:
// - _SHADOW_SAMPLE_NORMAL_OFFSET
// - _SHADOW_SAMPLE_ORTHO
// - _SHADOW_SAMPLE_POINT
// - _SHADOW_SAMPLE_SOURCE_ZBUFFER
fn getShadowSampleCoord{i}(shadowTransform: mat4x4f, shadowParams: vec4f, worldPosition: vec3f, lightPos: vec3f, lightDir: ptr<function, vec3f>, lightDirNorm: vec3f, normal: vec3f) -> vec3f {
var surfacePosition = worldPosition;
let distScale: f32 = length(*lightDir);
surfacePosition = surfacePosition + normal * shadowParams.y * clamp(1.0 - dot(normal, -lightDirNorm), 0.0, 1.0) * distScale;
*lightDir = surfacePosition - lightPos;
return *lightDir;
surfacePosition = surfacePosition + normal * shadowParams.y;
var distScale: f32 = 1.0;
var distScale: f32 = abs(dot(vPositionW - lightPos, lightDirNorm));
surfacePosition = surfacePosition + normal * shadowParams.y * clamp(1.0 - dot(normal, -lightDirNorm), 0.0, 1.0) * distScale;
// Use var for modification
var positionInShadowSpace: vec4f = shadowTransform * vec4f(surfacePosition, 1.0);
positionInShadowSpace.z = saturate(positionInShadowSpace.z) - 0.0001;
positionInShadowSpace.xyz = positionInShadowSpace.xyz / positionInShadowSpace.w;
positionInShadowSpace.xy = positionInShadowSpace.xy / positionInShadowSpace.w;
positionInShadowSpace.z = length(*lightDir) * shadowParams.w;
// this is currently unused
// positionInShadowSpace.z += getShadowBias(shadowParams.x, shadowParams.z);
surfacePosition = positionInShadowSpace.xyz;
return surfacePosition;
}
// shadow evaluation function
fn getShadow{i}(lightDirW_in: vec3f) -> f32 {
// directional shadow cascades
// select shadow cascade matrix
var cascadeIndex: i32 = getShadowCascadeIndex(uniform.light{i}_shadowCascadeDistances, uniform.light{i}_shadowCascadeCount);
cascadeIndex = ditherShadowCascadeIndex(cascadeIndex, uniform.light{i}_shadowCascadeDistances, uniform.light{i}_shadowCascadeCount, uniform.light{i}_shadowCascadeBlend);
var shadowMatrix: mat4x4f = uniform.light{i}_shadowMatrixPalette[cascadeIndex];
var shadowMatrix: mat4x4f = uniform.light{i}_shadowMatrix;
var lightDirArg = lightDirW_in;
// directional light does not have a position
var shadowCoord: vec3f = getShadowSampleCoord{i}(shadowMatrix, uniform.light{i}_shadowParams, vPositionW, vec3f(0.0), &lightDirArg, dLightDirNormW, dVertexNormalW);
var shadowCoord: vec3f = getShadowSampleCoord{i}(shadowMatrix, uniform.light{i}_shadowParams, vPositionW, uniform.light{i}_position, &lightDirArg, dLightDirNormW, dVertexNormalW);
// Fade directional shadow at the far distance
shadowCoord = fadeShadow(shadowCoord, uniform.light{i}_shadowCascadeDistances);
// ----- sample the shadow -----
return getShadowVSM16(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, 5.54);
return getShadowVSM32(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, 15.0);
let shadowSearchArea = vec2f(length(uniform.light{i}_halfWidth), length(uniform.light{i}_halfHeight)) * uniform.light{i}_shadowSearchArea;
return getShadowPCSS(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, uniform.light{i}_cameraParams, shadowSearchArea, lightDirW_in);
return getShadowPCSS(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, uniform.light{i}_cameraParams, uniform.light{i}_softShadowParams, lightDirW_in);
return getShadowPCF1x1(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
return getShadowPCF3x3(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
return getShadowPCF5x5(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
return getShadowSpotVSM16(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, 5.54, lightDirW_in);
return getShadowSpotVSM32(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, 15.0, lightDirW_in);
var shadowSearchArea: vec2f = vec2f(length(uniform.light{i}_halfWidth), length(uniform.light{i}_halfHeight)) * uniform.light{i}_shadowSearchArea;
var shadowSearchArea: vec2f = vec2f(uniform.light{i}_shadowSearchArea);
return getShadowSpotPCSS(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, uniform.light{i}_cameraParams, shadowSearchArea, lightDirW_in);
return getShadowSpotPCF1x1(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
return getShadowSpotPCF3x3(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
return getShadowSpotPCF5x5(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams);
var shadowSearchArea: vec2f; // Use var because assigned in if/else
var shadowSearchArea: vec2f = vec2f(length(uniform.light{i}_halfWidth), length(uniform.light{i}_halfHeight)) * uniform.light{i}_shadowSearchArea;
var shadowSearchArea: vec2f = vec2f(uniform.light{i}_shadowSearchArea);
return getShadowOmniPCSS(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, uniform.light{i}_cameraParams, shadowSearchArea, lightDirW_in);
return getShadowOmniPCF1x1(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, lightDirW_in);
return getShadowOmniPCF3x3(light{i}_shadowMap, light{i}_shadowMapSampler, shadowCoord, uniform.light{i}_shadowParams, lightDirW_in);
}
`;
export { lightFunctionShadowPS as default };