[Port] [6000.4] Fixed precision for shadows over large distances

Author: svc-reach-platform-support

Packages/com.unity.render-pipelines.core/ShaderLibrary/CommonLighting.hlsl

@@ -79,7 +79,7 @@ real ConvertLuminanceToEv(real luminance)
 
 // Non physically based hack to limit light influence to attenuationRadius.
 // Square the result to smoothen the function.
-real DistanceWindowing(real distSquare, real rangeAttenuationScale, real rangeAttenuationBias)
+real DistanceWindowing(float distSquare, real rangeAttenuationScale, real rangeAttenuationBias)
 {
     // If (range attenuation is enabled)
     //   rangeAttenuationScale = 1 / r^2

Packages/com.unity.render-pipelines.core/ShaderLibrary/Shadow/ShadowSamplingTent.hlsl

@@ -106,7 +106,7 @@ void SampleShadow_GetTexelWeights_Tent_7x7(real offset, out real4 texelsWeightsA
 }
 
 // 3x3 Tent filter (45 degree sloped triangles in U and V)
-void SampleShadow_ComputeSamples_Tent_3x3(real4 shadowMapTexture_TexelSize, real2 coord, out real fetchesWeights[4], out real2 fetchesUV[4])
+void SampleShadow_ComputeSamples_Tent_3x3(real4 shadowMapTexture_TexelSize, float2 coord, out real fetchesWeights[4], out real2 fetchesUV[4])
 {
     // tent base is 3x3 base thus covering from 9 to 12 texels, thus we need 4 bilinear PCF fetches
     real2 tentCenterInTexelSpace = coord.xy * shadowMapTexture_TexelSize.zw;
@@ -186,7 +186,7 @@ void SampleShadow_ComputeSamples_Tent_3x3(real4 shadowMapTexture_TexelSize, real
     (fetchesWeights)[8] = fetchesWeightsU.z * fetchesWeightsV.z; \
 }
 
-void SampleShadow_ComputeSamples_Tent_5x5(real4 shadowMapTexture_TexelSize, real2 coord, out real fetchesWeights[9], out real2 fetchesUV[9])
+void SampleShadow_ComputeSamples_Tent_5x5(real4 shadowMapTexture_TexelSize, float2 coord, out real fetchesWeights[9], out real2 fetchesUV[9])
 {
     SampleShadow_ComputeSamples_Tent_Filter_5x5(real, shadowMapTexture_TexelSize, coord, fetchesWeights, fetchesUV);
 }
@@ -254,7 +254,7 @@ void SampleShadow_ComputeSamples_Tent_5x5(real4 shadowMapTexture_TexelSize, real
 
 
 
-void SampleShadow_ComputeSamples_Tent_7x7(real4 shadowMapTexture_TexelSize, real2 coord, out real fetchesWeights[16], out real2 fetchesUV[16])
+void SampleShadow_ComputeSamples_Tent_7x7(real4 shadowMapTexture_TexelSize, float2 coord, out real fetchesWeights[16], out real2 fetchesUV[16])
 {
     SampleShadow_ComputeSamples_Tent_Filter_7x7(real, shadowMapTexture_TexelSize, coord, fetchesWeights, fetchesUV);
 }

Packages/com.unity.render-pipelines.high-definition/Runtime/Lighting/LightEvaluation.hlsl

@@ -464,12 +464,12 @@ float4 EvaluateCookie_Punctual(LightLoopContext lightLoopContext, LightData ligh
     return cookie;
 }
 
-real PunctualLightAttenuationWithDistanceModification(real4 distances, real rangeAttenuationScale, real rangeAttenuationBias,
+real PunctualLightAttenuationWithDistanceModification(float4 distances, real rangeAttenuationScale, real rangeAttenuationBias,
                               real lightAngleScale, real lightAngleOffset)
 {
-    real distSq   = distances.y;
-    real distRcp  = distances.z; //distance contains light size modification. See ModifyDistancesForFillLighting
-    real distProj = distances.w;
+    float distSq   = distances.y;
+    float distRcp  = distances.z; //distance contains light size modification. See ModifyDistancesForFillLighting
+    float distProj = distances.w;
     real cosFwd   = distProj * rcp(distances.x); //we recompute inv distance here
 
     real attenuation = min(distRcp, 1.0 / PUNCTUAL_LIGHT_THRESHOLD);