Merge pull request #1880 from Unity-Technologies/fabric_normal_decal

Supporting Normal Buffer Writing and Decals for the fabric shader

com.unity.render-pipelines.high-definition/HDRP/Material/Decal/DecalUtilities.hlsl

         if (mask & DBUFFERHTILEBIT_MASK)
         {
 #ifdef DECALS_4RT // only smoothness in 3RT mode
+    #if !defined(UNITY_MATERIAL_FABRIC)
+    #endif
 			surfaceData.ambientOcclusion = surfaceData.ambientOcclusion * decalSurfaceData.MAOSBlend.y + decalSurfaceData.mask.y;
 #endif
             surfaceData.perceptualSmoothness = surfaceData.perceptualSmoothness * decalSurfaceData.mask.w + decalSurfaceData.mask.z;

com.unity.render-pipelines.high-definition/HDRP/Material/Fabric/Fabric.hlsl

 #endif
 }
 
+NormalData ConvertSurfaceDataToNormalData(SurfaceData surfaceData)
+{
+    NormalData normalData;
+    normalData.normalWS = surfaceData.normalWS;
+    normalData.perceptualRoughness = PerceptualSmoothnessToPerceptualRoughness(surfaceData.perceptualSmoothness);
+    return normalData;
+}
+
 //-----------------------------------------------------------------------------
 // conversion function for forward
 //-----------------------------------------------------------------------------

com.unity.render-pipelines.high-definition/HDRP/Material/Fabric/Fabric.shader

 
             HLSLPROGRAM
 
+            #define WRITE_NORMAL_BUFFER
             #define SHADERPASS SHADERPASS_DEPTH_ONLY
             #include "HDRP/ShaderVariables.hlsl"
             #include "HDRP/Material/Material.hlsl"
             //#pragma multi_compile LIGHTLOOP_SINGLE_PASS LIGHTLOOP_TILE_PASS
             #define LIGHTLOOP_TILE_PASS
             #pragma multi_compile USE_FPTL_LIGHTLIST USE_CLUSTERED_LIGHTLIST
+            #pragma multi_compile DECALS_OFF DECALS_3RT DECALS_4RT
 
             #define SHADERPASS SHADERPASS_FORWARD
             #include "HDRP/ShaderVariables.hlsl"

com.unity.render-pipelines.high-definition/HDRP/Material/Fabric/FabricData.hlsl

 #include "CoreRP/ShaderLibrary/Sampling/SampleUVMapping.hlsl"
 #include "HDRP/Material/MaterialUtilities.hlsl"
 #include "HDRP/Material/BuiltinUtilities.hlsl"
+#include "HDRP/Material/Decal/DecalUtilities.hlsl"
 
 void GetSurfaceAndBuiltinData(FragInputs input, float3 V, inout PositionInputs posInput, out SurfaceData surfaceData, out BuiltinData builtinData)
 {
 
 #ifdef _ALPHATEST_ON
     DoAlphaTest(alpha, _AlphaCutoff);
+#endif
+
+#if HAVE_DECALS
+    AddDecalContribution(posInput, surfaceData, alpha);
 #endif
 
 #if defined(DEBUG_DISPLAY)