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// Various shadow sampling logic.
// Again two versions, one for dynamic resource indexing, one for static resource access.
// ------------------------------------------------------------------
// PCF Filtering helpers
// ------------------------------------------------------------------
// Assuming a isoceles right angled triangle of height "triangleHeight" (as drawn below).
// This function return the area of the triangle above the first texel.
//
// |\ <-- 45 degree slop isosceles right angled triangle
// | \
// ---- <-- length of this side is "triangleHeight"
// _ _ _ _ <-- texels
float SampleShadow_GetTriangleTexelArea(float triangleHeight)
{
return triangleHeight - 0.5;
}
// Assuming a isoceles triangle of 1.5 texels height and 3 texels wide lying on 4 texels.
// This function return the area of the triangle above each of those texels.
// | <-- offset from -0.5 to 0.5, 0 meaning triangle is exactly in the center
// / \ <-- 45 degree slop isosceles triangle (ie tent projected in 2D)
// / \
// _ _ _ _ <-- texels
// X Y Z W <-- result indices (in computedArea.xyzw and computedAreaUncut.xyzw)
void SampleShadow_GetTexelAreas_Tent_3x3(float offset, out float4 computedArea, out float4 computedAreaUncut)
{
// Compute the exterior areas
float offset01SquaredHalved = (offset + 0.5) * (offset + 0.5) * 0.5;
computedAreaUncut.x = computedArea.x = offset01SquaredHalved - offset;
computedAreaUncut.w = computedArea.w = offset01SquaredHalved;
// Compute the middle areas
// For Y : We find the area in Y of as if the left section of the isoceles triangle would
// intersect the axis between Y and Z (ie where offset = 0).
computedAreaUncut.y = SampleShadow_GetTriangleTexelArea(1.5 - offset);
// This area is superior to the one we are looking for if (offset < 0) thus we need to
// subtract the area of the triangle defined by (0,1.5-offset), (0,1.5+offset), (-offset,1.5).
float clampedOffsetLeft = min(offset,0);
float areaOfSmallLeftTriangle = clampedOffsetLeft * clampedOffsetLeft;
computedArea.y = computedAreaUncut.y - areaOfSmallLeftTriangle;
// We do the same for the Z but with the right part of the isoceles triangle
computedAreaUncut.z = SampleShadow_GetTriangleTexelArea(1.5 + offset);
float clampedOffsetRight = max(offset,0);
float areaOfSmallRightTriangle = clampedOffsetRight * clampedOffsetRight;
computedArea.z = computedAreaUncut.z - areaOfSmallRightTriangle;
}
// Assuming a isoceles triangle of 1.5 texels height and 3 texels wide lying on 4 texels.
// This function return the weight of each texels area relative to the full triangle area.
void SampleShadow_GetTexelWeights_Tent_3x3(float offset, out float4 computedWeight)
{
float4 dummy;
SampleShadow_GetTexelAreas_Tent_3x3(offset, computedWeight, dummy);
computedWeight *= 0.44444;//0.44 == 1/(the triangle area)
}
// Assuming a isoceles triangle of 2.5 texel height and 5 texels wide lying on 6 texels.
// This function return the weight of each texels area relative to the full triangle area.
// / \
// _ _ _ _ _ _ <-- texels
// 0 1 2 3 4 5 <-- computed area indices (in texelsWeights[])
void SampleShadow_GetTexelWeights_Tent_5x5(float offset, out float3 texelsWeightsA, out float3 texelsWeightsB)
{
// See _UnityInternalGetAreaPerTexel_3TexelTriangleFilter for details.
float4 computedArea_From3texelTriangle;
float4 computedAreaUncut_From3texelTriangle;
SampleShadow_GetTexelAreas_Tent_3x3(offset, computedArea_From3texelTriangle, computedAreaUncut_From3texelTriangle);
// Triangle slope is 45 degree thus we can almost reuse the result of the 3 texel wide computation.
// the 5 texel wide triangle can be seen as the 3 texel wide one but shifted up by one unit/texel.
// 0.16 is 1/(the triangle area)
texelsWeightsA.x = 0.16 * (computedArea_From3texelTriangle.x);
texelsWeightsA.y = 0.16 * (computedAreaUncut_From3texelTriangle.y);
texelsWeightsA.z = 0.16 * (computedArea_From3texelTriangle.y + 1);
texelsWeightsB.x = 0.16 * (computedArea_From3texelTriangle.z + 1);
texelsWeightsB.y = 0.16 * (computedAreaUncut_From3texelTriangle.z);
texelsWeightsB.z = 0.16 * (computedArea_From3texelTriangle.w);
}
// Assuming a isoceles triangle of 3.5 texel height and 7 texels wide lying on 8 texels.
// This function return the weight of each texels area relative to the full triangle area.
// / \
// _ _ _ _ _ _ _ _ <-- texels
// 0 1 2 3 4 5 6 7 <-- computed area indices (in texelsWeights[])
void SampleShadow_GetTexelWeights_Tent_7x7(float offset, out float4 texelsWeightsA, out float4 texelsWeightsB)
{
// See _UnityInternalGetAreaPerTexel_3TexelTriangleFilter for details.
float4 computedArea_From3texelTriangle;
float4 computedAreaUncut_From3texelTriangle;
SampleShadow_GetTexelAreas_Tent_3x3(offset, computedArea_From3texelTriangle, computedAreaUncut_From3texelTriangle);
// Triangle slope is 45 degree thus we can almost reuse the result of the 3 texel wide computation.
// the 7 texel wide triangle can be seen as the 3 texel wide one but shifted up by two unit/texel.
// 0.081632 is 1/(the triangle area)
texelsWeightsA.x = 0.081632 * (computedArea_From3texelTriangle.x);
texelsWeightsA.y = 0.081632 * (computedAreaUncut_From3texelTriangle.y);
texelsWeightsA.z = 0.081632 * (computedAreaUncut_From3texelTriangle.y + 1);
texelsWeightsA.w = 0.081632 * (computedArea_From3texelTriangle.y + 2);
texelsWeightsB.x = 0.081632 * (computedArea_From3texelTriangle.z + 2);
texelsWeightsB.y = 0.081632 * (computedAreaUncut_From3texelTriangle.z + 1);
texelsWeightsB.z = 0.081632 * (computedAreaUncut_From3texelTriangle.z);
texelsWeightsB.w = 0.081632 * (computedArea_From3texelTriangle.w);
}
// 3x3 Tent filter (45 degree sloped triangles in U and V)
void SampleShadow_ComputeSamples_Tent_3x3(float4 shadowMapTexture_TexelSize, float2 coord, out float fetchesWeights[4], out float2 fetchesUV[4])
{
// tent base is 3x3 base thus covering from 9 to 12 texels, thus we need 4 bilinear PCF fetches
float2 tentCenterInTexelSpace = coord.xy * shadowMapTexture_TexelSize.zw;
float2 centerOfFetchesInTexelSpace = floor(tentCenterInTexelSpace + 0.5);
float2 offsetFromTentCenterToCenterOfFetches = tentCenterInTexelSpace - centerOfFetchesInTexelSpace;
// find the weight of each texel based
float4 texelsWeightsU, texelsWeightsV;
SampleShadow_GetTexelWeights_Tent_3x3(offsetFromTentCenterToCenterOfFetches.x, texelsWeightsU);
SampleShadow_GetTexelWeights_Tent_3x3(offsetFromTentCenterToCenterOfFetches.y, texelsWeightsV);
// each fetch will cover a group of 2x2 texels, the weight of each group is the sum of the weights of the texels
float2 fetchesWeightsU = texelsWeightsU.xz + texelsWeightsU.yw;
float2 fetchesWeightsV = texelsWeightsV.xz + texelsWeightsV.yw;
// move the PCF bilinear fetches to respect texels weights
float2 fetchesOffsetsU = texelsWeightsU.yw / fetchesWeightsU.xy + float2(-1.5,0.5);
float2 fetchesOffsetsV = texelsWeightsV.yw / fetchesWeightsV.xy + float2(-1.5,0.5);
fetchesOffsetsU *= shadowMapTexture_TexelSize.xx;
fetchesOffsetsV *= shadowMapTexture_TexelSize.yy;
float2 bilinearFetchOrigin = centerOfFetchesInTexelSpace * shadowMapTexture_TexelSize.xy;
fetchesUV[0] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.x);
fetchesUV[1] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.x);
fetchesUV[2] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.y);
fetchesUV[3] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.y);
fetchesWeights[0] = fetchesWeightsU.x * fetchesWeightsV.x;
fetchesWeights[1] = fetchesWeightsU.y * fetchesWeightsV.x;
fetchesWeights[2] = fetchesWeightsU.x * fetchesWeightsV.y;
fetchesWeights[3] = fetchesWeightsU.y * fetchesWeightsV.y;
}
// 5x5 Tent filter (45 degree sloped triangles in U and V)
void SampleShadow_ComputeSamples_Tent_5x5(float4 shadowMapTexture_TexelSize, float2 coord, out float fetchesWeights[9], out float2 fetchesUV[9])
{
// tent base is 5x5 base thus covering from 25 to 36 texels, thus we need 9 bilinear PCF fetches
float2 tentCenterInTexelSpace = coord.xy * shadowMapTexture_TexelSize.zw;
float2 centerOfFetchesInTexelSpace = floor(tentCenterInTexelSpace + 0.5);
float2 offsetFromTentCenterToCenterOfFetches = tentCenterInTexelSpace - centerOfFetchesInTexelSpace;
// find the weight of each texel based on the area of a 45 degree slop tent above each of them.
float3 texelsWeightsU_A, texelsWeightsU_B;
float3 texelsWeightsV_A, texelsWeightsV_B;
SampleShadow_GetTexelWeights_Tent_5x5(offsetFromTentCenterToCenterOfFetches.x, texelsWeightsU_A, texelsWeightsU_B);
SampleShadow_GetTexelWeights_Tent_5x5(offsetFromTentCenterToCenterOfFetches.y, texelsWeightsV_A, texelsWeightsV_B);
// each fetch will cover a group of 2x2 texels, the weight of each group is the sum of the weights of the texels
float3 fetchesWeightsU = float3(texelsWeightsU_A.xz, texelsWeightsU_B.y) + float3(texelsWeightsU_A.y, texelsWeightsU_B.xz);
float3 fetchesWeightsV = float3(texelsWeightsV_A.xz, texelsWeightsV_B.y) + float3(texelsWeightsV_A.y, texelsWeightsV_B.xz);
// move the PCF bilinear fetches to respect texels weights
float3 fetchesOffsetsU = float3(texelsWeightsU_A.y, texelsWeightsU_B.xz) / fetchesWeightsU.xyz + float3(-2.5,-0.5,1.5);
float3 fetchesOffsetsV = float3(texelsWeightsV_A.y, texelsWeightsV_B.xz) / fetchesWeightsV.xyz + float3(-2.5,-0.5,1.5);
fetchesOffsetsU *= shadowMapTexture_TexelSize.xxx;
fetchesOffsetsV *= shadowMapTexture_TexelSize.yyy;
float2 bilinearFetchOrigin = centerOfFetchesInTexelSpace * shadowMapTexture_TexelSize.xy;
fetchesUV[0] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.x);
fetchesUV[1] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.x);
fetchesUV[2] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.x);
fetchesUV[3] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.y);
fetchesUV[4] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.y);
fetchesUV[5] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.y);
fetchesUV[6] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.z);
fetchesUV[7] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.z);
fetchesUV[8] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.z);
fetchesWeights[0] = fetchesWeightsU.x * fetchesWeightsV.x;
fetchesWeights[1] = fetchesWeightsU.y * fetchesWeightsV.x;
fetchesWeights[2] = fetchesWeightsU.z * fetchesWeightsV.x;
fetchesWeights[3] = fetchesWeightsU.x * fetchesWeightsV.y;
fetchesWeights[4] = fetchesWeightsU.y * fetchesWeightsV.y;
fetchesWeights[5] = fetchesWeightsU.z * fetchesWeightsV.y;
fetchesWeights[6] = fetchesWeightsU.x * fetchesWeightsV.z;
fetchesWeights[7] = fetchesWeightsU.y * fetchesWeightsV.z;
fetchesWeights[8] = fetchesWeightsU.z * fetchesWeightsV.z;
}
// 7x7 Tent filter (45 degree sloped triangles in U and V)
void SampleShadow_ComputeSamples_Tent_7x7(float4 shadowMapTexture_TexelSize, float2 coord, out float fetchesWeights[16], out float2 fetchesUV[16])
{
// tent base is 7x7 base thus covering from 49 to 64 texels, thus we need 16 bilinear PCF fetches
float2 tentCenterInTexelSpace = coord.xy * shadowMapTexture_TexelSize.zw;
float2 centerOfFetchesInTexelSpace = floor(tentCenterInTexelSpace + 0.5);
float2 offsetFromTentCenterToCenterOfFetches = tentCenterInTexelSpace - centerOfFetchesInTexelSpace;
// find the weight of each texel based on the area of a 45 degree slop tent above each of them.
float4 texelsWeightsU_A, texelsWeightsU_B;
float4 texelsWeightsV_A, texelsWeightsV_B;
SampleShadow_GetTexelWeights_Tent_7x7(offsetFromTentCenterToCenterOfFetches.x, texelsWeightsU_A, texelsWeightsU_B);
SampleShadow_GetTexelWeights_Tent_7x7(offsetFromTentCenterToCenterOfFetches.y, texelsWeightsV_A, texelsWeightsV_B);
// each fetch will cover a group of 2x2 texels, the weight of each group is the sum of the weights of the texels
float4 fetchesWeightsU = float4(texelsWeightsU_A.xz, texelsWeightsU_B.xz) + float4(texelsWeightsU_A.yw, texelsWeightsU_B.yw);
float4 fetchesWeightsV = float4(texelsWeightsV_A.xz, texelsWeightsV_B.xz) + float4(texelsWeightsV_A.yw, texelsWeightsV_B.yw);
// move the PCF bilinear fetches to respect texels weights
float4 fetchesOffsetsU = float4(texelsWeightsU_A.yw, texelsWeightsU_B.yw) / fetchesWeightsU.xyzw + float4(-3.5,-1.5,0.5,2.5);
float4 fetchesOffsetsV = float4(texelsWeightsV_A.yw, texelsWeightsV_B.yw) / fetchesWeightsV.xyzw + float4(-3.5,-1.5,0.5,2.5);
fetchesOffsetsU *= shadowMapTexture_TexelSize.xxxx;
fetchesOffsetsV *= shadowMapTexture_TexelSize.yyyy;
float2 bilinearFetchOrigin = centerOfFetchesInTexelSpace * shadowMapTexture_TexelSize.xy;
fetchesUV[0] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.x);
fetchesUV[1] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.x);
fetchesUV[2] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.x);
fetchesUV[3] = bilinearFetchOrigin + float2(fetchesOffsetsU.w, fetchesOffsetsV.x);
fetchesUV[4] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.y);
fetchesUV[5] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.y);
fetchesUV[6] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.y);
fetchesUV[7] = bilinearFetchOrigin + float2(fetchesOffsetsU.w, fetchesOffsetsV.y);
fetchesUV[8] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.z);
fetchesUV[9] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.z);
fetchesUV[10] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.z);
fetchesUV[11] = bilinearFetchOrigin + float2(fetchesOffsetsU.w, fetchesOffsetsV.z);
fetchesUV[12] = bilinearFetchOrigin + float2(fetchesOffsetsU.x, fetchesOffsetsV.w);
fetchesUV[13] = bilinearFetchOrigin + float2(fetchesOffsetsU.y, fetchesOffsetsV.w);
fetchesUV[14] = bilinearFetchOrigin + float2(fetchesOffsetsU.z, fetchesOffsetsV.w);
fetchesUV[15] = bilinearFetchOrigin + float2(fetchesOffsetsU.w, fetchesOffsetsV.w);
fetchesWeights[0] = fetchesWeightsU.x * fetchesWeightsV.x;
fetchesWeights[1] = fetchesWeightsU.y * fetchesWeightsV.x;
fetchesWeights[2] = fetchesWeightsU.z * fetchesWeightsV.x;
fetchesWeights[3] = fetchesWeightsU.w * fetchesWeightsV.x;
fetchesWeights[4] = fetchesWeightsU.x * fetchesWeightsV.y;
fetchesWeights[5] = fetchesWeightsU.y * fetchesWeightsV.y;
fetchesWeights[6] = fetchesWeightsU.z * fetchesWeightsV.y;
fetchesWeights[7] = fetchesWeightsU.w * fetchesWeightsV.y;
fetchesWeights[8] = fetchesWeightsU.x * fetchesWeightsV.z;
fetchesWeights[9] = fetchesWeightsU.y * fetchesWeightsV.z;
fetchesWeights[10] = fetchesWeightsU.z * fetchesWeightsV.z;
fetchesWeights[11] = fetchesWeightsU.w * fetchesWeightsV.z;
fetchesWeights[12] = fetchesWeightsU.x * fetchesWeightsV.w;
fetchesWeights[13] = fetchesWeightsU.y * fetchesWeightsV.w;
fetchesWeights[14] = fetchesWeightsU.z * fetchesWeightsV.w;
fetchesWeights[15] = fetchesWeightsU.w * fetchesWeightsV.w;
}
// ------------------------------------------------------------------
// PCF Filtering methods
// ------------------------------------------------------------------
//
// 1 tap PCF sampling
//
float SampleShadow_PCF_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, float bias, uint slice, uint texIdx, uint sampIdx )
{
float depthBias = asfloat( shadowContext.payloads[payloadOffset].x );
payloadOffset++;
// add the depth bias
tcs.z += depthBias;
// sample the texture
return SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, tcs, slice ).x;
}
float SampleShadow_PCF_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, float bias, uint slice, Texture2DArray tex, SamplerComparisonState compSamp )
{
float depthBias = asfloat( shadowContext.payloads[payloadOffset].x );
payloadOffset++;
// add the depth bias
tcs.z += depthBias;
// sample the texture
return SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, tcs, slice );
}
//
// 3x3 tent PCF sampling (4 taps)
//
float SampleShadow_PCF_Tent_3x3( ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, uint texIdx, uint sampIdx )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp?
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[4];
float2 fetchesUV[4];
SampleShadow_ComputeSamples_Tent_3x3(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
[loop] for (int i = 0; i < 4; i++)
{
shadow += fetchesWeights[i] * SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
float SampleShadow_PCF_Tent_3x3(ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, Texture2DArray tex, SamplerComparisonState compSamp )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp?
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[4];
float2 fetchesUV[4];
SampleShadow_ComputeSamples_Tent_3x3(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
for (int i = 0; i < 4; i++)
{
shadow += fetchesWeights[i] * SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
//
// 5x5 tent PCF sampling (9 taps)
//
float SampleShadow_PCF_Tent_5x5( ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, uint texIdx, uint sampIdx )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp?
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[9];
float2 fetchesUV[9];
SampleShadow_ComputeSamples_Tent_5x5(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
[loop] for (int i = 0; i < 9; i++)
{
shadow += fetchesWeights[i] * SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
float SampleShadow_PCF_Tent_5x5(ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, Texture2DArray tex, SamplerComparisonState compSamp )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[9];
float2 fetchesUV[9];
SampleShadow_ComputeSamples_Tent_5x5(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
for (int i = 0; i < 9; i++)
{
shadow += fetchesWeights[i] * SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
//
// 7x7 tent PCF sampling (16 taps)
//
float SampleShadow_PCF_Tent_7x7( ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, uint texIdx, uint sampIdx )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[16];
float2 fetchesUV[16];
SampleShadow_ComputeSamples_Tent_7x7(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
[loop] for (int i = 0; i < 16; i++)
{
shadow += fetchesWeights[i] * SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
float SampleShadow_PCF_Tent_7x7(ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 coord, uint slice, Texture2DArray tex, SamplerComparisonState compSamp )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
payloadOffset++;
// TODO move this to shadow data to avoid the rcp
float4 shadowMapTexture_TexelSize = float4(texelSizeRcp.xy, rcp(texelSizeRcp.xy));
// add the depth bias
coord.z += depthBias;
float shadow = 0.0;
float fetchesWeights[16];
float2 fetchesUV[16];
SampleShadow_ComputeSamples_Tent_7x7(shadowMapTexture_TexelSize, coord.xy, fetchesWeights, fetchesUV);
for (int i = 0; i < 16; i++)
{
shadow += fetchesWeights[i] * SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( fetchesUV[i].xy, coord.z ), slice ).x;
}
return shadow;
}
//
// 9 tap adaptive PCF sampling
//
float SampleShadow_PCF_9tap_Adaptive( ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 tcs, float bias, uint slice, uint texIdx, uint sampIdx )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
float filterSize = params.y;
payloadOffset++;
texelSizeRcp *= filterSize;
// add the depth bias
tcs.z += depthBias;
// Terms0 are weights for the individual samples, the other terms are offsets in texel space
float4 vShadow3x3PCFTerms0 = float4( 20.0f / 267.0f, 33.0f / 267.0f, 55.0f / 267.0f, 0.0f );
float4 vShadow3x3PCFTerms1 = float4( texelSizeRcp.x, texelSizeRcp.y, -texelSizeRcp.x, -texelSizeRcp.y );
float4 vShadow3x3PCFTerms2 = float4( texelSizeRcp.x, texelSizeRcp.y, 0.0f, 0.0f );
float4 vShadow3x3PCFTerms3 = float4(-texelSizeRcp.x, -texelSizeRcp.y, 0.0f, 0.0f );
float4 v20Taps;
v20Taps.x = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms1.xy, tcs.z ), slice ).x; // 1 1
v20Taps.y = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms1.zy, tcs.z ), slice ).x; // -1 1
v20Taps.z = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms1.xw, tcs.z ), slice ).x; // 1 -1
v20Taps.w = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms1.zw, tcs.z ), slice ).x; // -1 -1
float flSum = dot( v20Taps.xyzw, float4( 0.25, 0.25, 0.25, 0.25 ) );
// fully in light or shadow? -> bail
if( ( flSum == 0.0 ) || ( flSum == 1.0 ) )
return flSum;
// we're in a transition area, do 5 more taps
flSum *= vShadow3x3PCFTerms0.x * 4.0;
float4 v33Taps;
v33Taps.x = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms2.xz, tcs.z ), slice ).x; // 1 0
v33Taps.y = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms3.xz, tcs.z ), slice ).x; // -1 0
v33Taps.z = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms3.zy, tcs.z ), slice ).x; // 0 -1
v33Taps.w = SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, float3( tcs.xy + vShadow3x3PCFTerms2.zy, tcs.z ), slice ).x; // 0 1
flSum += dot( v33Taps.xyzw, vShadow3x3PCFTerms0.yyyy );
flSum += SampleCompShadow_T2DA( shadowContext, texIdx, sampIdx, tcs, slice ).x * vShadow3x3PCFTerms0.z;
return flSum;
}
float SampleShadow_PCF_9tap_Adaptive(ShadowContext shadowContext, inout uint payloadOffset, float4 texelSizeRcp, float3 tcs, float bias, uint slice, Texture2DArray tex, SamplerComparisonState compSamp )
{
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float depthBias = params.x;
float filterSize = params.y;
payloadOffset++;
texelSizeRcp *= filterSize;
// add the depth bias
tcs.z += depthBias;
// Terms0 are weights for the individual samples, the other terms are offsets in texel space
float4 vShadow3x3PCFTerms0 = float4(20.0f / 267.0f, 33.0f / 267.0f, 55.0f / 267.0f, 0.0f);
float4 vShadow3x3PCFTerms1 = float4( texelSizeRcp.x, texelSizeRcp.y, -texelSizeRcp.x, -texelSizeRcp.y);
float4 vShadow3x3PCFTerms2 = float4( texelSizeRcp.x, texelSizeRcp.y, 0.0f, 0.0f);
float4 vShadow3x3PCFTerms3 = float4(-texelSizeRcp.x, -texelSizeRcp.y, 0.0f, 0.0f);
float4 v20Taps;
v20Taps.x = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms1.xy, tcs.z ), slice ).x; // 1 1
v20Taps.y = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms1.zy, tcs.z ), slice ).x; // -1 1
v20Taps.z = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms1.xw, tcs.z ), slice ).x; // 1 -1
v20Taps.w = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms1.zw, tcs.z ), slice ).x; // -1 -1
float flSum = dot( v20Taps.xyzw, float4( 0.25, 0.25, 0.25, 0.25 ) );
// fully in light or shadow? -> bail
if( ( flSum == 0.0 ) || ( flSum == 1.0 ) )
return flSum;
// we're in a transition area, do 5 more taps
flSum *= vShadow3x3PCFTerms0.x * 4.0;
float4 v33Taps;
v33Taps.x = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms2.xz, tcs.z ), slice ).x; // 1 0
v33Taps.y = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms3.xz, tcs.z ), slice ).x; // -1 0
v33Taps.z = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms3.zy, tcs.z ), slice ).x; // 0 -1
v33Taps.w = SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, float3( tcs.xy + vShadow3x3PCFTerms2.zy, tcs.z ), slice ).x; // 0 1
flSum += dot( v33Taps.xyzw, vShadow3x3PCFTerms0.yyyy );
flSum += SAMPLE_TEXTURE2D_ARRAY_SHADOW( tex, compSamp, tcs, slice ).x * vShadow3x3PCFTerms0.z;
return flSum;
}
#include "ShadowMoments.hlsl"
//
// 1 tap VSM sampling
//
float SampleShadow_VSM_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, uint texIdx, uint sampIdx )
{
#if UNITY_REVERSED_Z
float depth = 1.0 - tcs.z;
#else
float depth = tcs.z;
#endif
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float lightLeakBias = params.x;
float varianceBias = params.y;
payloadOffset++;
float2 moments = SampleShadow_T2DA( shadowContext, texIdx, sampIdx, tcs.xy, slice ).xy;
return ShadowMoments_ChebyshevsInequality( moments, depth, varianceBias, lightLeakBias );
}
float SampleShadow_VSM_1tap(ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, Texture2DArray tex, SamplerState samp )
{
#if UNITY_REVERSED_Z
float depth = 1.0 - tcs.z;
#else
float depth = tcs.z;
#endif
float2 params = asfloat( shadowContext.payloads[payloadOffset].xy );
float lightLeakBias = params.x;
float varianceBias = params.y;
payloadOffset++;
float2 moments = SAMPLE_TEXTURE2D_ARRAY_LOD( tex, samp, tcs.xy, slice, 0.0 ).xy;
return ShadowMoments_ChebyshevsInequality( moments, depth, varianceBias, lightLeakBias );
}
//
// 1 tap EVSM sampling
//
float SampleShadow_EVSM_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, uint texIdx, uint sampIdx, bool fourMoments )
{
#if UNITY_REVERSED_Z
float depth = 1.0 - tcs.z;
#else
float depth = tcs.z;
#endif
float4 params = asfloat( shadowContext.payloads[payloadOffset] );
float lightLeakBias = params.x;
float varianceBias = params.y;
float2 evsmExponents = params.zw;
payloadOffset++;
float2 warpedDepth = ShadowMoments_WarpDepth( depth, evsmExponents );
float4 moments = SampleShadow_T2DA( shadowContext, texIdx, sampIdx, tcs.xy, slice );
// Derivate of warping at depth
float2 depthScale = evsmExponents * warpedDepth;
float2 minVariance = depthScale * depthScale * varianceBias;
[branch]
if( fourMoments )
{
float posContrib = ShadowMoments_ChebyshevsInequality( moments.xz, warpedDepth.x, minVariance.x, lightLeakBias );
float negContrib = ShadowMoments_ChebyshevsInequality( moments.yw, warpedDepth.y, minVariance.y, lightLeakBias );
return min( posContrib, negContrib );
}
else
{
return ShadowMoments_ChebyshevsInequality( moments.xy, warpedDepth.x, minVariance.x, lightLeakBias );
}
}
float SampleShadow_EVSM_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, Texture2DArray tex, SamplerState samp, bool fourMoments )
{
#if UNITY_REVERSED_Z
float depth = 1.0 - tcs.z;
#else
float depth = tcs.z;
#endif
float4 params = asfloat( shadowContext.payloads[payloadOffset] );
float lightLeakBias = params.x;
float varianceBias = params.y;
float2 evsmExponents = params.zw;
payloadOffset++;
float2 warpedDepth = ShadowMoments_WarpDepth( depth, evsmExponents );
float4 moments = SAMPLE_TEXTURE2D_ARRAY_LOD( tex, samp, tcs.xy, slice, 0.0 );
// Derivate of warping at depth
float2 depthScale = evsmExponents * warpedDepth;
float2 minVariance = depthScale * depthScale * varianceBias;
[branch]
if( fourMoments )
{
float posContrib = ShadowMoments_ChebyshevsInequality( moments.xz, warpedDepth.x, minVariance.x, lightLeakBias );
float negContrib = ShadowMoments_ChebyshevsInequality( moments.yw, warpedDepth.y, minVariance.y, lightLeakBias );
return min( posContrib, negContrib );
}
else
{
return ShadowMoments_ChebyshevsInequality( moments.xy, warpedDepth.x, minVariance.x, lightLeakBias );
}
}
//
// 1 tap MSM sampling
//
float SampleShadow_MSM_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, uint texIdx, uint sampIdx, bool useHamburger )
{
float4 params = asfloat( shadowContext.payloads[payloadOffset] );
float lightLeakBias = params.x;
float momentBias = params.y;
float depthBias = params.z;
float bpp16 = params.w;
#if UNITY_REVERSED_Z
float depth = (1.0 - tcs.z) - depthBias;
#else
float depth = tcs.z + depthBias;
#endif
payloadOffset++;
float4 moments = SampleShadow_T2DA( shadowContext, texIdx, sampIdx, tcs.xy, slice );
if( bpp16 != 0.0 )
moments = ShadowMoments_Decode16MSM( moments );
float3 z;
float4 b;
ShadowMoments_SolveMSM( moments, depth, momentBias, z, b );
if( useHamburger )
return ShadowMoments_SolveDelta3MSM( z, b.xy, lightLeakBias );
else
return (z[1] < 0.0 || z[2] > 1.0) ? ShadowMoments_SolveDelta4MSM( z, b, lightLeakBias ) : ShadowMoments_SolveDelta3MSM( z, b.xy, lightLeakBias );
}
float SampleShadow_MSM_1tap( ShadowContext shadowContext, inout uint payloadOffset, float3 tcs, uint slice, Texture2DArray tex, SamplerState samp, bool useHamburger )
{
float4 params = asfloat( shadowContext.payloads[payloadOffset] );
float lightLeakBias = params.x;
float momentBias = params.y;
float depthBias = params.z;
float bpp16 = params.w;
#if UNITY_REVERSED_Z
float depth = (1.0 - tcs.z) - depthBias;
#else
float depth = tcs.z + depthBias;
#endif
payloadOffset++;
float4 moments = SAMPLE_TEXTURE2D_ARRAY_LOD( tex, samp, tcs.xy, slice, 0.0 );
if( bpp16 != 0.0 )
moments = ShadowMoments_Decode16MSM( moments );
float3 z;
float4 b;
ShadowMoments_SolveMSM( moments, depth, momentBias, z, b );
if( useHamburger )
return ShadowMoments_SolveDelta3MSM( z, b.xy, lightLeakBias );
else
return (z[1] < 0.0 || z[2] > 1.0) ? ShadowMoments_SolveDelta4MSM( z, b, lightLeakBias ) : ShadowMoments_SolveDelta3MSM( z, b.xy, lightLeakBias );
}
//-----------------------------------------------------------------------------------------------------
// helper function to dispatch a specific shadow algorithm
float SampleShadow_SelectAlgorithm( ShadowContext shadowContext, ShadowData shadowData, inout uint payloadOffset, float3 posTC, float depthBias, uint slice, uint algorithm, uint texIdx, uint sampIdx )
{
[branch]
switch( algorithm )
{
case GPUSHADOWALGORITHM_PCF_1TAP : return SampleShadow_PCF_1tap( shadowContext, payloadOffset, posTC, depthBias, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_PCF_9TAP : return SampleShadow_PCF_9tap_Adaptive( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, depthBias, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_PCF_TENT_3X3 : return SampleShadow_PCF_Tent_3x3( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_PCF_TENT_5X5 : return SampleShadow_PCF_Tent_5x5( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_PCF_TENT_7X7 : return SampleShadow_PCF_Tent_7x7( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_VSM : return SampleShadow_VSM_1tap( shadowContext, payloadOffset, posTC, slice, texIdx, sampIdx );
case GPUSHADOWALGORITHM_EVSM_2 : return SampleShadow_EVSM_1tap( shadowContext, payloadOffset, posTC, slice, texIdx, sampIdx, false );
case GPUSHADOWALGORITHM_EVSM_4 : return SampleShadow_EVSM_1tap( shadowContext, payloadOffset, posTC, slice, texIdx, sampIdx, true );
case GPUSHADOWALGORITHM_MSM_HAM : return SampleShadow_MSM_1tap( shadowContext, payloadOffset, posTC, slice, texIdx, sampIdx, true );
case GPUSHADOWALGORITHM_MSM_HAUS : return SampleShadow_MSM_1tap( shadowContext, payloadOffset, posTC, slice, texIdx, sampIdx, false );
default: return 1.0;
}
}
float SampleShadow_SelectAlgorithm( ShadowContext shadowContext, ShadowData shadowData, inout uint payloadOffset, float3 posTC, float depthBias, uint slice, uint algorithm, Texture2DArray tex, SamplerComparisonState compSamp )
{
[branch]
switch( algorithm )
{
case GPUSHADOWALGORITHM_PCF_1TAP : return SampleShadow_PCF_1tap( shadowContext, payloadOffset, posTC, depthBias, slice, tex, compSamp );
case GPUSHADOWALGORITHM_PCF_9TAP : return SampleShadow_PCF_9tap_Adaptive( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, depthBias, slice, tex, compSamp );
case GPUSHADOWALGORITHM_PCF_TENT_3X3 : return SampleShadow_PCF_Tent_3x3( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, tex, compSamp );
case GPUSHADOWALGORITHM_PCF_TENT_5X5 : return SampleShadow_PCF_Tent_5x5( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, tex, compSamp );
case GPUSHADOWALGORITHM_PCF_TENT_7X7 : return SampleShadow_PCF_Tent_7x7( shadowContext, payloadOffset, shadowData.texelSizeRcp, posTC, slice, tex, compSamp );
default: return 1.0;
}
}
float SampleShadow_SelectAlgorithm( ShadowContext shadowContext, ShadowData shadowData, inout uint payloadOffset, float3 posTC, float depthBias, uint slice, uint algorithm, Texture2DArray tex, SamplerState samp )
{
[branch]
switch( algorithm )
{
case GPUSHADOWALGORITHM_VSM : return SampleShadow_VSM_1tap( shadowContext, payloadOffset, posTC, slice, tex, samp );
case GPUSHADOWALGORITHM_EVSM_2 : return SampleShadow_EVSM_1tap( shadowContext, payloadOffset, posTC, slice, tex, samp, false );
case GPUSHADOWALGORITHM_EVSM_4 : return SampleShadow_EVSM_1tap( shadowContext, payloadOffset, posTC, slice, tex, samp, true );
case GPUSHADOWALGORITHM_MSM_HAM : return SampleShadow_MSM_1tap( shadowContext, payloadOffset, posTC, slice, tex, samp, true );
case GPUSHADOWALGORITHM_MSM_HAUS : return SampleShadow_MSM_1tap( shadowContext, payloadOffset, posTC, slice, tex, samp, false );
default: return 1.0;
}
}