declare const _default: "\n\n// ------ VSM Shared ------\n\nfloat linstep(float a, float b, float v) {\n    return saturate((v - a) / (b - a));\n}\n\nfloat reduceLightBleeding(float pMax, float amount) {\n   // Remove the [0, amount] tail and linearly rescale (amount, 1].\n   return linstep(amount, 1.0, pMax);\n}\n\nfloat chebyshevUpperBound(vec2 moments, float mean, float minVariance, float lightBleedingReduction) {\n    // Compute variance\n    float variance = moments.y - (moments.x * moments.x);\n    variance = max(variance, minVariance);\n\n    // Compute probabilistic upper bound\n    float d = mean - moments.x;\n    float pMax = variance / (variance + (d * d));\n\n    pMax = reduceLightBleeding(pMax, lightBleedingReduction);\n\n    // One-tailed Chebyshev\n    return (mean <= moments.x ? 1.0 : pMax);\n}\n\nfloat calculateEVSM(vec3 moments, float Z, float vsmBias, float exponent) {\n    Z = 2.0 * Z - 1.0;\n    float warpedDepth = exp(exponent * Z);\n\n    moments.xy += vec2(warpedDepth, warpedDepth*warpedDepth) * (1.0 - moments.z);\n\n    float VSMBias = vsmBias;//0.01 * 0.25;\n    float depthScale = VSMBias * exponent * warpedDepth;\n    float minVariance1 = depthScale * depthScale;\n    return chebyshevUpperBound(moments.xy, warpedDepth, minVariance1, 0.1);\n}\n\n// ------ VSM 16 ------\n\nfloat VSM16(TEXTURE_ACCEPT(tex), vec2 texCoords, float resolution, float Z, float vsmBias, float exponent) {\n    vec3 moments = texture2DLod(tex, texCoords, 0.0).xyz;\n    return calculateEVSM(moments, Z, vsmBias, exponent);\n}\n\nfloat getShadowVSM16(TEXTURE_ACCEPT(shadowMap), vec3 shadowCoord, vec4 shadowParams, float exponent) {\n    return VSM16(TEXTURE_PASS(shadowMap), shadowCoord.xy, shadowParams.x, shadowCoord.z, shadowParams.y, exponent);\n}\n\nfloat getShadowSpotVSM16(TEXTURE_ACCEPT(shadowMap), vec3 shadowCoord, vec4 shadowParams, float exponent, vec3 lightDir) {\n    return VSM16(TEXTURE_PASS(shadowMap), shadowCoord.xy, shadowParams.x, length(lightDir) * shadowParams.w + shadowParams.z, shadowParams.y, exponent);\n}\n\n// ------ VSM 32 ------\n\nfloat VSM32(TEXTURE_ACCEPT(tex), vec2 texCoords, float resolution, float Z, float vsmBias, float exponent) {\n\n    #ifdef CAPS_TEXTURE_FLOAT_FILTERABLE\n        vec3 moments = texture2DLod(tex, texCoords, 0.0).xyz;\n    #else\n        // manual bilinear filtering\n        float pixelSize = 1.0 / resolution;\n        texCoords -= vec2(pixelSize);\n        vec3 s00 = texture2DLod(tex, texCoords, 0.0).xyz;\n        vec3 s10 = texture2DLod(tex, texCoords + vec2(pixelSize, 0), 0.0).xyz;\n        vec3 s01 = texture2DLod(tex, texCoords + vec2(0, pixelSize), 0.0).xyz;\n        vec3 s11 = texture2DLod(tex, texCoords + vec2(pixelSize), 0.0).xyz;\n        vec2 fr = fract(texCoords * resolution);\n        vec3 h0 = mix(s00, s10, fr.x);\n        vec3 h1 = mix(s01, s11, fr.x);\n        vec3 moments = mix(h0, h1, fr.y);\n    #endif\n\n    return calculateEVSM(moments, Z, vsmBias, exponent);\n}\n\nfloat getShadowVSM32(TEXTURE_ACCEPT(shadowMap), vec3 shadowCoord, vec4 shadowParams, float exponent) {\n    return VSM32(TEXTURE_PASS(shadowMap), shadowCoord.xy, shadowParams.x, shadowCoord.z, shadowParams.y, exponent);\n}\n\nfloat getShadowSpotVSM32(TEXTURE_ACCEPT(shadowMap), vec3 shadowCoord, vec4 shadowParams, float exponent, vec3 lightDir) {\n    return VSM32(TEXTURE_PASS(shadowMap), shadowCoord.xy, shadowParams.x, length(lightDir) * shadowParams.w + shadowParams.z, shadowParams.y, exponent);\n}\n";
export default _default;