Add normal buffer to directional shadow and forwar

+ add poistion input to prototype of ConvertSurfaceDataToBSDFData

com.unity.render-pipelines.high-definition/HDRP/Lighting/DeferredDirectionalShadow.compute

 // Each #kernel tells which function to compile; you can have many kernels
 #pragma kernel DeferredDirectionalShadow                    DEFERRED_DIRECTIONAL=DeferredDirectionalShadow
 #pragma kernel DeferredDirectionalShadow_Contact            DEFERRED_DIRECTIONAL=DeferredDirectionalShadow_Contact          ENABLE_CONTACT_SHADOWS
-#pragma kernel DeferredDirectionalShadow_Normals            DEFERRED_DIRECTIONAL=DeferredDirectionalShadow_Normals          ENABLE_NORMALS
-#pragma kernel DeferredDirectionalShadow_Contact_Normals    DEFERRED_DIRECTIONAL=DeferredDirectionalShadow_Contact_Normals  ENABLE_CONTACT_SHADOWS ENABLE_NORMALS
-
-#ifdef ENABLE_NORMALS
-#   define LIGHTLOOP_TILE_PASS 1
-#   define USE_FPTL_LIGHTLIST  1 // deferred opaque always use FPTL
-#   define UNITY_MATERIAL_LIT
-#else
-#   define SHADOW_USE_ONLY_VIEW_BASED_BIASING 1   // Enable only light view vector based biasing. If undefined, biasing will be based on the normal and calling code must provide a valid normal.
-#endif
 
 #ifdef SHADER_API_PSSL
 #   pragma argument( scheduler=minpressure ) // instruct the shader compiler to prefer minimizing vgpr usage
 #include "../ShaderVariables.hlsl"
+#include "../Material/NormalBuffer.hlsl"
 #include "Lighting.hlsl"
 
 #pragma only_renderers d3d11 ps4 xboxone vulkan metal switch
 
     PositionInputs posInput = GetPositionInput(pixelCoord.xy, _ScreenSize.zw, depth, UNITY_MATRIX_I_VP, UNITY_MATRIX_V, tileCoord);
 
-#ifdef ENABLE_NORMALS
-    BSDFData bsdfData;
-    BakeLightingData unused;
-    DECODE_FROM_GBUFFER(posInput.positionSS, UINT_MAX, bsdfData, unused.bakeDiffuseLighting);
-    float3 nrm = bsdfData.normalWS;
-#else
-    float3 nrm = 0.0.xxx;
-#endif
+    NormalData normalData;
+    DecodeFromNormalBuffer(posInput.positionSS, normalData);
+    float3 normalWS = normalData.normalWS;
-    float shadow = GetDirectionalShadowAttenuation(shadowContext, posInput.positionWS, nrm, _DirectionalShadowIndex, _LightDirection);
+    float shadow = GetDirectionalShadowAttenuation(shadowContext, posInput.positionWS, normalWS, _DirectionalShadowIndex, _LightDirection);
 
 #ifdef ENABLE_CONTACT_SHADOWS
     float contactShadow = 1.0f;

com.unity.render-pipelines.high-definition/HDRP/Lighting/LightLoop/LightLoop.cs

 
         static int s_deferredDirectionalShadowKernel;
         static int s_deferredDirectionalShadow_Contact_Kernel;
-        static int s_deferredDirectionalShadow_Normals_Kernel;
-        static int s_deferredDirectionalShadow_Contact_Normals_Kernel;
 
         static ComputeBuffer s_LightVolumeDataBuffer = null;
         static ComputeBuffer s_ConvexBoundsBuffer = null;
 
             s_deferredDirectionalShadowKernel = deferredDirectionalShadowComputeShader.FindKernel("DeferredDirectionalShadow");
             s_deferredDirectionalShadow_Contact_Kernel = deferredDirectionalShadowComputeShader.FindKernel("DeferredDirectionalShadow_Contact");
-            s_deferredDirectionalShadow_Normals_Kernel = deferredDirectionalShadowComputeShader.FindKernel("DeferredDirectionalShadow_Normals");
-            s_deferredDirectionalShadow_Contact_Normals_Kernel = deferredDirectionalShadowComputeShader.FindKernel("DeferredDirectionalShadow_Contact_Normals");
 
             for (int variant = 0; variant < LightDefinitions.s_NumFeatureVariants; variant++)
             {
                 bool enableContactShadows = m_FrameSettings.enableContactShadows && contactShadows.enable && contactShadows.length > 0.0f;
                 int kernel;
                 if (enableContactShadows)
-                    kernel = m_FrameSettings.enableForwardRenderingOnly ? s_deferredDirectionalShadow_Contact_Kernel : s_deferredDirectionalShadow_Contact_Normals_Kernel;
+                    kernel = s_deferredDirectionalShadow_Contact_Kernel;
-                    kernel = m_FrameSettings.enableForwardRenderingOnly ? s_deferredDirectionalShadowKernel : s_deferredDirectionalShadow_Normals_Kernel;
+                    kernel = s_deferredDirectionalShadowKernel;
 
                 m_ShadowMgr.BindResources(cmd, deferredDirectionalShadowComputeShader, kernel);
 

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

     return normalData;
 }
 
+void UpdateSurfaceDataFromNormalData(uint2 positionSS, inout SurfaceData surfaceData)
+{
+    NormalData normalData;
+
+    DecodeFromNormalBuffer(positionSS, normalData);
+
+    surfaceData.normalWS = normalData.normalWS;
+
+    // If we have store clear coat smoothness in the texture, don't override perceptualSmoothness
+    // Note: Compiler is always able to optimize this code as we are in forward, so with static flag
+    // so the condition will be remove and the read texture will correctly happen instead of all the code
+    // to provide perceptualSmoothness
+    if (!HasFeatureFlag(surfaceData.materialFeatures, MATERIALFEATUREFLAGS_LIT_CLEAR_COAT))
+    {
+        surfaceData.perceptualSmoothness = normalData.perceptualSmoothness;
+    }
+}
+
-BSDFData ConvertSurfaceDataToBSDFData(SurfaceData surfaceData)
+BSDFData ConvertSurfaceDataToBSDFData(uint2 positionSS, SurfaceData surfaceData)
+
+    // In forward we can chose between reading the normal from the normalBufferTexture or computing it again
+    // Reading normal will suffer from compression, thus using following code depends on tradeoff between performance and quality.
+    // Test it for your project
+
+    // #define READ_FORWARD_NORMAL_FROM_TEXTURE
+#ifdef READ_FORWARD_NORMAL_FROM_TEXTURE
+#if SHADERPASS == SHADERPASS_FORWARD
+    UpdateSurfaceDataFromNormalData(positionSS, surfaceData);
+#endif
+#endif
 
     // IMPORTANT: In case of foward or gbuffer pass all enable flags are statically know at compile time, so the compiler can do compile time optimization
     bsdfData.materialFeatures    = surfaceData.materialFeatures;

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

 
             ZWrite On
 
-            //ColorMask 0
-
-            #pragma multi_compile _ OUTPUT_NORMAL_BUFFER
+            #pragma multi_compile _ WRITE_NORMAL_BUFFER
 
             #define SHADERPASS SHADERPASS_DEPTH_ONLY
             #include "../../ShaderVariables.hlsl"

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

 
     // It is safe to call this function here as surfaceData have been filled
     // We want to know if we must enable transmission on GI for SSS material, if the material have no SSS, this code will be remove by the compiler.
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
     if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_LIT_TRANSMISSION))
     {
         // For now simply recall the function with inverted normal, the compiler should be able to optimize the lightmap case to not resample the directional lightmap

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

+#include "CoreRP/ShaderLibrary/Packing.hlsl"
+#include "CoreRP/ShaderLibrary/CommonMaterial.hlsl"
+
 // ----------------------------------------------------------------------------
 // Encoding/decoding normal buffer functions
 // ----------------------------------------------------------------------------
 }
 
 // OUTPUT_NORMAL_NORMALBUFFER start from SV_Target0 as it is used during depth prepass where there is no color buffer
-#define OUTPUT_NORMAL_NORMALBUFFER(NAME) out NormalBufferType0 MERGE_NAME(NAME, 0) : SV_Target0
+#define OUTPUT_NORMALBUFFER(NAME) out NormalBufferType0 MERGE_NAME(NAME, 0) : SV_Target0
 #define ENCODE_INTO_NORMALBUFFER(SURFACE_DATA, UNPOSITIONSS, NAME) EncodeIntoNormalBuffer(ConvertSurfaceDataToNormalData(SURFACE_DATA), UNPOSITIONSS, MERGE_NAME(NAME, 0))
 
 #define DECODE_FROM_NORMALBUFFER(UNPOSITIONSS, NORMAL_DATA) DecodeFromNormalBuffer(UNPOSITIONSS, NORMAL_DATA)

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

 // conversion function for forward
 //-----------------------------------------------------------------------------
 
-BSDFData ConvertSurfaceDataToBSDFData(SurfaceData surfaceData)
+BSDFData ConvertSurfaceDataToBSDFData(uint2 positionSS, SurfaceData surfaceData)
 {
     BSDFData bsdfData;
     ZERO_INITIALIZE(BSDFData, bsdfData);

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

 
             HLSLPROGRAM
 
+            #define WRITE_NORMAL_BUFFER
             #define SHADERPASS SHADERPASS_DEPTH_ONLY
             #include "../../ShaderVariables.hlsl"
             #include "../../Material/Material.hlsl"

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

 
     // It is safe to call this function here as surfaceData have been filled
     // We want to know if we must enable transmission on GI for SSS material, if the material have no SSS, this code will be remove by the compiler.
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
     if (HasFeatureFlag(bsdfData.materialFeatures, MATERIALFEATUREFLAGS_STACK_LIT_TRANSMISSION))
     {
         // For now simply recall the function with inverted normal, the compiler should be able to optimize the lightmap case to not resample the directional lightmap

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

 // conversion function for forward
 //-----------------------------------------------------------------------------
 
-BSDFData ConvertSurfaceDataToBSDFData(SurfaceData data)
+BSDFData ConvertSurfaceDataToBSDFData(uint2 positionSS, SurfaceData data)
 {
     BSDFData output;
     output.color = data.color;

com.unity.render-pipelines.high-definition/HDRP/ShaderPass/ShaderPassDepthOnly.hlsl

 #endif // TESSELLATION_ON
 
 void Frag(  PackedVaryingsToPS packedInput,
-            #ifdef OUTPUT_NORMAL_BUFFER
+            #ifdef WRITE_NORMAL_BUFFER
             OUTPUT_NORMALBUFFER(outNormalBuffer)
             #else
             out float4 outColor : SV_Target
     outputDepth = posInput.deviceDepth;
 #endif
 
-#ifdef OUTPUT_NORMAL_BUFFER
+#ifdef WRITE_NORMAL_BUFFER
     ENCODE_INTO_NORMALBUFFER(surfaceData, posInput.positionSS, outNormalBuffer);
 #elif defined(SCENESELECTIONPASS)
     // We use depth prepass for scene selection in the editor, this code allow to output the outline correctly

com.unity.render-pipelines.high-definition/HDRP/ShaderPass/ShaderPassForward.hlsl

     ApplyDebugToSurfaceData(input.worldToTangent, surfaceData);
 #endif
 
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
 
     PreLightData preLightData = GetPreLightData(V, posInput, bsdfData);
 

com.unity.render-pipelines.high-definition/HDRP/ShaderPass/ShaderPassForwardUnlit.hlsl

     GetSurfaceAndBuiltinData(input, V, posInput, surfaceData, builtinData);
 
     // Not lit here (but emissive is allowed)
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
 
     // TODO: we must not access bsdfData here, it break the genericity of the code!
     float4 outColor = ApplyBlendMode(bsdfData.color + builtinData.emissiveColor, builtinData.opacity);

com.unity.render-pipelines.high-definition/HDRP/ShaderPass/ShaderPassGBuffer.hlsl

     ApplyDebugToSurfaceData(input.worldToTangent, surfaceData);
 #endif
 
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
 
     PreLightData preLightData = GetPreLightData(V, posInput, bsdfData);
 

com.unity.render-pipelines.high-definition/HDRP/ShaderPass/ShaderPassLightTransport.hlsl

 
     // no debug apply during light transport pass
 
-    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(surfaceData);
+    BSDFData bsdfData = ConvertSurfaceDataToBSDFData(input.positionSS.xy, surfaceData);
     LightTransportData lightTransportData = GetLightTransportData(surfaceData, builtinData, bsdfData);
 
     // This shader is call two times. Once for getting emissiveColor, the other time to get diffuseColor