playcanvas/build/playcanvas.dbg/src/scene/shader-lib/chunks/lit/frag/clusteredLight.js

PlayCanvas WebGL game engine

var clusteredLightPS = "\nuniform highp sampler2D clusterWorldTexture;\nuniform highp sampler2D lightsTexture8;\nuniform highp sampler2D lightsTextureFloat;\n\n#ifdef CLUSTER_SHADOWS\n    // TODO: when VSM shadow is supported, it needs to use sampler2D in webgl2\n    uniform sampler2DShadow shadowAtlasTexture;\n#endif\n\n#ifdef CLUSTER_COOKIES\n    uniform sampler2D cookieAtlasTexture;\n#endif\n\nuniform int clusterMaxCells;\n\n// 1.0 if clustered lighting can be skipped (0 lights in the clusters)\nuniform float clusterSkip;\n\nuniform vec3 clusterCellsCountByBoundsSize;\nuniform vec3 clusterTextureSize;\nuniform vec3 clusterBoundsMin;\nuniform vec3 clusterBoundsDelta;\nuniform vec3 clusterCellsDot;\nuniform vec3 clusterCellsMax;\nuniform vec2 clusterCompressionLimit0;\nuniform vec2 shadowAtlasParams;\n\n// structure storing light properties of a clustered light\n// it's sorted to have all vectors aligned to 4 floats to limit padding\nstruct ClusterLightData {\n\n    // area light sizes / orientation\n    vec3 halfWidth;\n\n    // type of the light (spot or omni)\n    float lightType;\n\n    // area light sizes / orientation\n    vec3 halfHeight;\n\n    // light index\n    int lightIndex;\n\n    // world space position\n    vec3 position;\n\n    // area light shape\n    float shape;\n\n    // world space direction (spot light only)\n    vec3 direction;\n\n    // light follow mode\n    float falloffMode;\n\n    // color\n    vec3 color;\n\n    // 0.0 if the light doesn't cast shadows\n    float shadowIntensity;\n\n    // atlas viewport for omni light shadow and cookie (.xy is offset to the viewport slot, .z is size of the face in the atlas)\n    vec3 omniAtlasViewport;\n\n    // range of the light\n    float range;\n\n    // channel mask - one of the channels has 1, the others are 0\n    vec4 cookieChannelMask;\n\n    // shadow bias values\n    float shadowBias;\n    float shadowNormalBias;\n\n    // spot light inner and outer angle cosine\n    float innerConeAngleCos;\n    float outerConeAngleCos;\n\n    // 1.0 if the light has a cookie texture\n    float cookie;\n\n    // 1.0 if cookie texture is rgb, otherwise it is using a single channel selectable by cookieChannelMask\n    float cookieRgb;\n\n    // intensity of the cookie\n    float cookieIntensity;\n\n    // light mask\n    float mask;\n};\n\n// Note: on some devices (tested on Pixel 3A XL), this matrix when stored inside the light struct has lower precision compared to\n// when stored outside, so we store it outside to avoid spot shadow flickering. This might need to be done to other / all members\n// of the structure if further similar issues are observed.\n\n// shadow (spot light only) / cookie projection matrix\nmat4 lightProjectionMatrix;\n\n// macros for light properties\nbool isClusteredLightCastShadow(in ClusterLightData light) {\n  return light.shadowIntensity > 0.0;\n}\n\nbool isClusteredLightCookie(in ClusterLightData light) {\n  return light.cookie > 0.5;\n}\n\nbool isClusteredLightCookieRgb(in ClusterLightData light) {\n  return light.cookieRgb > 0.5;\n}\n\nbool isClusteredLightSpot(in ClusterLightData light) {\n  return light.lightType > 0.5;\n}\n\nbool isClusteredLightFalloffLinear(in ClusterLightData light) {\n  return light.falloffMode < 0.5;\n}\n\n// macros to test light shape\n// Note: Following functions need to be called serially in listed order as they do not test both '>' and '<'\nbool isClusteredLightArea(in ClusterLightData light) {\n  return light.shape > 0.1;\n}\n\nbool isClusteredLightRect(in ClusterLightData light) {\n  return light.shape < 0.3;\n}\n\nbool isClusteredLightDisk(in ClusterLightData light) {\n  return light.shape < 0.6;\n}\n\n// macro to test light mask (mesh accepts dynamic vs lightmapped lights)\n#ifdef CLUSTER_MESH_DYNAMIC_LIGHTS\n    // accept lights marked as dynamic or both dynamic and lightmapped\n    bool acceptLightMask(in ClusterLightData light) {\n        return light.mask < 0.75;\n    }\n#else\n    // accept lights marked as lightmapped or both dynamic and lightmapped\n    bool acceptLightMask(in ClusterLightData light) {\n        return light.mask > 0.25;\n    }\n#endif\n\nvec4 decodeClusterLowRange4Vec4(vec4 d0, vec4 d1, vec4 d2, vec4 d3) {\n    return vec4(\n        bytes2floatRange4(d0, -2.0, 2.0),\n        bytes2floatRange4(d1, -2.0, 2.0),\n        bytes2floatRange4(d2, -2.0, 2.0),\n        bytes2floatRange4(d3, -2.0, 2.0)\n    );\n}\n\nvec4 sampleLightsTexture8(const ClusterLightData clusterLightData, int index) {\n    return texelFetch(lightsTexture8, ivec2(index, clusterLightData.lightIndex), 0);\n}\n\nvec4 sampleLightTextureF(const ClusterLightData clusterLightData, int index) {\n    return texelFetch(lightsTextureFloat, ivec2(index, clusterLightData.lightIndex), 0);\n}\n\nvoid decodeClusterLightCore(inout ClusterLightData clusterLightData, float lightIndex) {\n\n    // light index\n    clusterLightData.lightIndex = int(lightIndex);\n\n    // shared data from 8bit texture\n    vec4 lightInfo = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_FLAGS);\n    clusterLightData.lightType = lightInfo.x;\n    clusterLightData.shape = lightInfo.y;\n    clusterLightData.falloffMode = lightInfo.z;\n    clusterLightData.shadowIntensity = lightInfo.w;\n\n    // color\n    vec4 colorA = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_COLOR_A);\n    vec4 colorB = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_COLOR_B);\n    clusterLightData.color = vec3(bytes2float2(colorA.xy), bytes2float2(colorA.zw), bytes2float2(colorB.xy)) * clusterCompressionLimit0.y;\n\n    // cookie\n    clusterLightData.cookie = colorB.z;\n\n    // light mask\n    clusterLightData.mask = colorB.w;\n\n    vec4 lightPosRange = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_POSITION_RANGE);\n    clusterLightData.position = lightPosRange.xyz;\n    clusterLightData.range = lightPosRange.w;\n\n    // spot light direction\n    vec4 lightDir_Unused = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_SPOT_DIRECTION);\n    clusterLightData.direction = lightDir_Unused.xyz;\n}\n\nvoid decodeClusterLightSpot(inout ClusterLightData clusterLightData) {\n\n    // spot light cos angles\n    vec4 coneAngle = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_SPOT_ANGLES);\n    clusterLightData.innerConeAngleCos = bytes2float2(coneAngle.xy) * 2.0 - 1.0;\n    clusterLightData.outerConeAngleCos = bytes2float2(coneAngle.zw) * 2.0 - 1.0;\n}\n\nvoid decodeClusterLightOmniAtlasViewport(inout ClusterLightData clusterLightData) {\n    clusterLightData.omniAtlasViewport = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_PROJ_MAT_0).xyz;\n}\n\nvoid decodeClusterLightAreaData(inout ClusterLightData clusterLightData) {\n    clusterLightData.halfWidth = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_AREA_DATA_WIDTH).xyz;\n    clusterLightData.halfHeight = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_AREA_DATA_HEIGHT).xyz;\n}\n\nvoid decodeClusterLightProjectionMatrixData(inout ClusterLightData clusterLightData) {\n    \n    // shadow matrix\n    vec4 m0 = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_PROJ_MAT_0);\n    vec4 m1 = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_PROJ_MAT_1);\n    vec4 m2 = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_PROJ_MAT_2);\n    vec4 m3 = sampleLightTextureF(clusterLightData, CLUSTER_TEXTURE_F_PROJ_MAT_3);\n    lightProjectionMatrix = mat4(m0, m1, m2, m3);\n}\n\nvoid decodeClusterLightShadowData(inout ClusterLightData clusterLightData) {\n    \n    // shadow biases\n    vec4 biases = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_SHADOW_BIAS);\n    clusterLightData.shadowBias = bytes2floatRange2(biases.xy, -1.0, 20.0),\n    clusterLightData.shadowNormalBias = bytes2float2(biases.zw);\n}\n\nvoid decodeClusterLightCookieData(inout ClusterLightData clusterLightData) {\n\n    vec4 cookieA = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_COOKIE_A);\n    clusterLightData.cookieIntensity = cookieA.x;\n    clusterLightData.cookieRgb = cookieA.y;\n\n    clusterLightData.cookieChannelMask = sampleLightsTexture8(clusterLightData, CLUSTER_TEXTURE_8_COOKIE_B);\n}\n\nvoid evaluateLight(\n    ClusterLightData light, \n    vec3 worldNormal, \n    vec3 viewDir, \n    vec3 reflectionDir,\n#if defined(LIT_CLEARCOAT)\n    vec3 clearcoatReflectionDir,\n#endif\n    float gloss, \n    vec3 specularity, \n    vec3 geometricNormal, \n    mat3 tbn, \n#if defined(LIT_IRIDESCENCE)\n    vec3 iridescenceFresnel,\n#endif\n    vec3 clearcoat_worldNormal,\n    float clearcoat_gloss,\n    float sheen_gloss,\n    float iridescence_intensity\n) {\n\n    vec3 cookieAttenuation = vec3(1.0);\n    float diffuseAttenuation = 1.0;\n    float falloffAttenuation = 1.0;\n\n    // evaluate omni part of the light\n    vec3 lightDirW;\n    vec3 lightDirNormW;\n    evalOmniLight(light.position, lightDirW, lightDirNormW);\n\n    #ifdef CLUSTER_AREALIGHTS\n\n    // distance attenuation\n    if (isClusteredLightArea(light)) { // area light\n\n        // area lights\n        decodeClusterLightAreaData(light);\n\n        // handle light shape\n        if (isClusteredLightRect(light)) {\n            calcRectLightValues(light.position, light.halfWidth, light.halfHeight);\n        } else if (isClusteredLightDisk(light)) {\n            calcDiskLightValues(light.position, light.halfWidth, light.halfHeight);\n        } else { // sphere\n            calcSphereLightValues(light.position, light.halfWidth, light.halfHeight);\n        }\n\n        falloffAttenuation = getFalloffWindow(light.range, lightDirW);\n\n    } else\n\n    #endif\n\n    {   // punctual light\n\n        if (isClusteredLightFalloffLinear(light))\n            falloffAttenuation = getFalloffLinear(light.range, lightDirW);\n        else\n            falloffAttenuation = getFalloffInvSquared(light.range, lightDirW);\n    }\n\n    if (falloffAttenuation > 0.00001) {\n\n        #ifdef CLUSTER_AREALIGHTS\n\n        if (isClusteredLightArea(light)) { // area light\n\n            // handle light shape\n            if (isClusteredLightRect(light)) {\n                diffuseAttenuation = getRectLightDiffuse(worldNormal, viewDir, lightDirW, lightDirNormW) * 16.0;\n            } else if (isClusteredLightDisk(light)) {\n                diffuseAttenuation = getDiskLightDiffuse(worldNormal, viewDir, lightDirW, lightDirNormW) * 16.0;\n            } else { // sphere\n                diffuseAttenuation = getSphereLightDiffuse(worldNormal, viewDir, lightDirW, lightDirNormW) * 16.0;\n            }\n\n        } else\n\n        #endif\n\n        {\n            falloffAttenuation *= getLightDiffuse(worldNormal, viewDir, lightDirNormW); \n        }\n\n        // spot light falloff\n        if (isClusteredLightSpot(light)) {\n            decodeClusterLightSpot(light);\n            falloffAttenuation *= getSpotEffect(light.direction, light.innerConeAngleCos, light.outerConeAngleCos, lightDirNormW);\n        }\n\n        #if defined(CLUSTER_COOKIES) || defined(CLUSTER_SHADOWS)\n\n        if (falloffAttenuation > 0.00001) {\n\n            // shadow / cookie\n            if (isClusteredLightCastShadow(light) || isClusteredLightCookie(light)) {\n\n                // shared shadow / cookie data depends on light type\n                if (isClusteredLightSpot(light)) {\n                    decodeClusterLightProjectionMatrixData(light);\n                } else {\n                    decodeClusterLightOmniAtlasViewport(light);\n                }\n\n                float shadowTextureResolution = shadowAtlasParams.x;\n                float shadowEdgePixels = shadowAtlasParams.y;\n\n                #ifdef CLUSTER_COOKIES\n\n                // cookie\n                if (isClusteredLightCookie(light)) {\n                    decodeClusterLightCookieData(light);\n\n                    if (isClusteredLightSpot(light)) {\n                        cookieAttenuation = getCookie2DClustered(TEXTURE_PASS(cookieAtlasTexture), lightProjectionMatrix, vPositionW, light.cookieIntensity, isClusteredLightCookieRgb(light), light.cookieChannelMask);\n                    } else {\n                        cookieAttenuation = getCookieCubeClustered(TEXTURE_PASS(cookieAtlasTexture), lightDirW, light.cookieIntensity, isClusteredLightCookieRgb(light), light.cookieChannelMask, shadowTextureResolution, shadowEdgePixels, light.omniAtlasViewport);\n                    }\n                }\n\n                #endif\n\n                #ifdef CLUSTER_SHADOWS\n\n                // shadow\n                if (isClusteredLightCastShadow(light)) {\n                    decodeClusterLightShadowData(light);\n\n                    vec4 shadowParams = vec4(shadowTextureResolution, light.shadowNormalBias, light.shadowBias, 1.0 / light.range);\n\n                    if (isClusteredLightSpot(light)) {\n\n                        // spot shadow\n                        vec3 shadowCoord = getShadowCoordPerspZbufferNormalOffset(lightProjectionMatrix, shadowParams, geometricNormal);\n                        \n                        #if defined(CLUSTER_SHADOW_TYPE_PCF1)\n                            float shadow = getShadowSpotClusteredPCF1(SHADOWMAP_PASS(shadowAtlasTexture), shadowCoord, shadowParams);\n                        #elif defined(CLUSTER_SHADOW_TYPE_PCF3)\n                            float shadow = getShadowSpotClusteredPCF3(SHADOWMAP_PASS(shadowAtlasTexture), shadowCoord, shadowParams);\n                        #elif defined(CLUSTER_SHADOW_TYPE_PCF5)\n                            float shadow = getShadowSpotClusteredPCF5(SHADOWMAP_PASS(shadowAtlasTexture), shadowCoord, shadowParams);\n                        #elif defined(CLUSTER_SHADOW_TYPE_PCSS)\n                            float shadow = getShadowSpotClusteredPCSS(SHADOWMAP_PASS(shadowAtlasTexture), shadowCoord, shadowParams);\n                        #endif\n                        falloffAttenuation *= mix(1.0, shadow, light.shadowIntensity);\n\n                    } else {\n\n                        // omni shadow\n                        vec3 dir = normalOffsetPointShadow(shadowParams, light.position, lightDirW, lightDirNormW, geometricNormal);  // normalBias adjusted for distance\n\n                        #if defined(CLUSTER_SHADOW_TYPE_PCF1)\n                            float shadow = getShadowOmniClusteredPCF1(SHADOWMAP_PASS(shadowAtlasTexture), shadowParams, light.omniAtlasViewport, shadowEdgePixels, dir);\n                        #elif defined(CLUSTER_SHADOW_TYPE_PCF3)\n                            float shadow = getShadowOmniClusteredPCF3(SHADOWMAP_PASS(shadowAtlasTexture), shadowParams, light.omniAtlasViewport, shadowEdgePixels, dir);\n                        #elif defined(CLUSTER_SHADOW_TYPE_PCF5)\n                            float shadow = getShadowOmniClusteredPCF5(SHADOWMAP_PASS(shadowAtlasTexture), shadowParams, light.omniAtlasViewport, shadowEdgePixels, dir);\n                        #endif\n                        falloffAttenuation *= mix(1.0, shadow, light.shadowIntensity);\n                    }\n                }\n\n                #endif\n            }\n        }\n\n        #endif\n\n        // diffuse / specular / clearcoat\n        #ifdef CLUSTER_AREALIGHTS\n\n        if (isClusteredLightArea(light)) { // area light\n\n            // area light diffuse\n            {\n                vec3 areaDiffuse = (diffuseAttenuation * falloffAttenuation) * light.color * cookieAttenuation;\n\n                #if defined(LIT_SPECULAR)\n                    areaDiffuse = mix(areaDiffuse, vec3(0), dLTCSpecFres);\n                #endif\n\n                // area light diffuse - it does not mix diffuse lighting into specular attenuation\n                dDiffuseLight += areaDiffuse;\n            }\n\n            // specular and clear coat are material settings and get included by a define based on the material\n            #ifdef LIT_SPECULAR\n\n                // area light specular\n                float areaLightSpecular;\n\n                if (isClusteredLightRect(light)) {\n                    areaLightSpecular = getRectLightSpecular(worldNormal, viewDir);\n                } else if (isClusteredLightDisk(light)) {\n                    areaLightSpecular = getDiskLightSpecular(worldNormal, viewDir);\n                } else { // sphere\n                    areaLightSpecular = getSphereLightSpecular(worldNormal, viewDir);\n                }\n\n                dSpecularLight += dLTCSpecFres * areaLightSpecular * falloffAttenuation * light.color * cookieAttenuation;\n\n                #ifdef LIT_CLEARCOAT\n\n                    // area light specular clear coat\n                    float areaLightSpecularCC;\n\n                    if (isClusteredLightRect(light)) {\n                        areaLightSpecularCC = getRectLightSpecular(clearcoat_worldNormal, viewDir);\n                    } else if (isClusteredLightDisk(light)) {\n                        areaLightSpecularCC = getDiskLightSpecular(clearcoat_worldNormal, viewDir);\n                    } else { // sphere\n                        areaLightSpecularCC = getSphereLightSpecular(clearcoat_worldNormal, viewDir);\n                    }\n\n                    ccSpecularLight += ccLTCSpecFres * areaLightSpecularCC * falloffAttenuation * light.color  * cookieAttenuation;\n\n                #endif\n\n            #endif\n\n        } else\n\n        #endif\n\n        {    // punctual light\n\n            // punctual light diffuse\n            {\n                vec3 punctualDiffuse = falloffAttenuation * light.color * cookieAttenuation;\n\n                #if defined(CLUSTER_AREALIGHTS)\n                #if defined(LIT_SPECULAR)\n                    punctualDiffuse = mix(punctualDiffuse, vec3(0), specularity);\n                #endif\n                #endif\n\n                dDiffuseLight += punctualDiffuse;\n            }\n   \n            // specular and clear coat are material settings and get included by a define based on the material\n            #ifdef LIT_SPECULAR\n\n                vec3 halfDir = normalize(-lightDirNormW + viewDir);\n                \n                // specular\n                #ifdef LIT_SPECULAR_FRESNEL\n                    dSpecularLight += \n                        getLightSpecular(halfDir, reflectionDir, worldNormal, viewDir, lightDirNormW, gloss, tbn) * falloffAttenuation * light.color * cookieAttenuation * \n                        getFresnel(\n                            dot(viewDir, halfDir), \n                            gloss, \n                            specularity\n                        #if defined(LIT_IRIDESCENCE)\n                            , iridescenceFresnel,\n                            iridescence_intensity\n                        #endif\n                            );\n                #else\n                    dSpecularLight += getLightSpecular(halfDir, reflectionDir, worldNormal, viewDir, lightDirNormW, gloss, tbn) * falloffAttenuation * light.color * cookieAttenuation * specularity;\n                #endif\n\n                #ifdef LIT_CLEARCOAT\n                    #ifdef LIT_SPECULAR_FRESNEL\n                        ccSpecularLight += getLightSpecular(halfDir, clearcoatReflectionDir, clearcoat_worldNormal, viewDir, lightDirNormW, clearcoat_gloss, tbn) * falloffAttenuation * light.color * cookieAttenuation * getFresnelCC(dot(viewDir, halfDir));\n                    #else\n                        ccSpecularLight += getLightSpecular(halfDir, clearcoatReflectionDir, clearcoat_worldNormal, viewDir, lightDirNormW, clearcoat_gloss, tbn) * falloffAttenuation * light.color * cookieAttenuation; \n                    #endif\n                #endif\n\n                #ifdef LIT_SHEEN\n                    sSpecularLight += getLightSpecularSheen(halfDir, worldNormal, viewDir, lightDirNormW, sheen_gloss) * falloffAttenuation * light.color * cookieAttenuation;\n                #endif\n\n            #endif\n        }\n    }\n\n    // Write to global attenuation values (for lightmapper)\n    dAtten = falloffAttenuation;\n    dLightDirNormW = lightDirNormW;\n}\n\nvoid evaluateClusterLight(\n    float lightIndex, \n    vec3 worldNormal, \n    vec3 viewDir, \n    vec3 reflectionDir, \n#if defined(LIT_CLEARCOAT)\n    vec3 clearcoatReflectionDir,\n#endif\n    float gloss, \n    vec3 specularity, \n    vec3 geometricNormal, \n    mat3 tbn, \n#if defined(LIT_IRIDESCENCE)\n    vec3 iridescenceFresnel,\n#endif\n    vec3 clearcoat_worldNormal,\n    float clearcoat_gloss,\n    float sheen_gloss,\n    float iridescence_intensity\n) {\n\n    // decode core light data from textures\n    ClusterLightData clusterLightData;\n    decodeClusterLightCore(clusterLightData, lightIndex);\n\n    // evaluate light if it uses accepted light mask\n    if (acceptLightMask(clusterLightData))\n        evaluateLight(\n            clusterLightData, \n            worldNormal, \n            viewDir, \n            reflectionDir, \n#if defined(LIT_CLEARCOAT)\n            clearcoatReflectionDir, \n#endif\n            gloss, \n            specularity, \n            geometricNormal, \n            tbn, \n#if defined(LIT_IRIDESCENCE)\n            iridescenceFresnel,\n#endif\n            clearcoat_worldNormal,\n            clearcoat_gloss,\n            sheen_gloss,\n            iridescence_intensity\n        );\n}\n\nvoid addClusteredLights(\n    vec3 worldNormal, \n    vec3 viewDir, \n    vec3 reflectionDir, \n#if defined(LIT_CLEARCOAT)\n    vec3 clearcoatReflectionDir,\n#endif\n    float gloss, \n    vec3 specularity, \n    vec3 geometricNormal, \n    mat3 tbn, \n#if defined(LIT_IRIDESCENCE)\n    vec3 iridescenceFresnel,\n#endif\n    vec3 clearcoat_worldNormal,\n    float clearcoat_gloss,\n    float sheen_gloss,\n    float iridescence_intensity\n) {\n\n    // skip lights if no lights at all\n    if (clusterSkip > 0.5)\n        return;\n\n    // world space position to 3d integer cell cordinates in the cluster structure\n    vec3 cellCoords = floor((vPositionW - clusterBoundsMin) * clusterCellsCountByBoundsSize);\n\n    // no lighting when cell coordinate is out of range\n    if (!(any(lessThan(cellCoords, vec3(0.0))) || any(greaterThanEqual(cellCoords, clusterCellsMax)))) {\n\n        // cell index (mapping from 3d cell coordinates to linear memory)\n        float cellIndex = dot(clusterCellsDot, cellCoords);\n\n        // convert cell index to uv coordinates\n        float clusterV = floor(cellIndex * clusterTextureSize.y);\n        float clusterU = cellIndex - (clusterV * clusterTextureSize.x);\n\n        // loop over maximum number of light cells\n        for (int lightCellIndex = 0; lightCellIndex < clusterMaxCells; lightCellIndex++) {\n\n            // using a single channel texture with data in alpha channel\n            float lightIndex = texelFetch(clusterWorldTexture, ivec2(int(clusterU) + lightCellIndex, clusterV), 0).x;\n\n            if (lightIndex <= 0.0)\n                    return;\n\n            evaluateClusterLight(\n                lightIndex * 255.0, \n                worldNormal, \n                viewDir, \n                reflectionDir,\n#if defined(LIT_CLEARCOAT)\n                clearcoatReflectionDir,\n#endif\n                gloss, \n                specularity, \n                geometricNormal, \n                tbn, \n#if defined(LIT_IRIDESCENCE)\n                iridescenceFresnel,\n#endif\n                clearcoat_worldNormal,\n                clearcoat_gloss,\n                sheen_gloss,\n                iridescence_intensity\n            ); \n        }\n    }\n}\n";

export { clusteredLightPS as default };