cleaned up gecal group culling code, mask blend uses total material blend

ScriptableRenderPipeline/HDRenderPipeline/Decal/DecalProjectorComponent.cs

         {
             DrawGizmo(true);
             // if this object is selected there is a chance the transform was changed so update culling info
-            DecalSystem.instance.UpdateCulling(this);
+            DecalSystem.instance.UpdateBoundingSphere(this);
         }
 
 		public void UpdatePropertyBlock(Vector3 cameraPos)

ScriptableRenderPipeline/HDRenderPipeline/Decal/DecalSystem.cs

                 return m_Instance;
             }
         }
-
-        internal List<DecalProjectorComponent> m_Decals = new List<DecalProjectorComponent>();
+        
-        private BoundingSphere[] m_BoundingSpheres;
-		private int[] m_ResultIndices;
+		private const int kDecalBlockSize = 128;
+		private BoundingSphere[] m_BoundingSpheres = new BoundingSphere[kDecalBlockSize];
+		private DecalProjectorComponent[] m_Decals = new DecalProjectorComponent[kDecalBlockSize];
+		private int[] m_ResultIndices = new int[kDecalBlockSize];
+		private int m_DecalsCount = 0;
      
         public DecalSystem()
         {
-        // updates bounding spheres for all decals, also refreshes cull indices
-        void UpdateCulling()
+        // update bounding sphere for a single decal
+        public void UpdateBoundingSphere(DecalProjectorComponent decal)
-            m_BoundingSpheres = new BoundingSphere[m_Decals.Count];
-			m_ResultIndices = new int[m_Decals.Count];
-            int cullIndex = 0;
-            foreach (var decal in m_Decals)
-            {
-                decal.CullIndex = cullIndex;
-                m_BoundingSpheres[cullIndex] = CoreUtils.GetDecalMeshBoundingSphere(decal.transform.localToWorldMatrix);
-                cullIndex++;
-            }           
+			m_BoundingSpheres[decal.CullIndex] = CoreUtils.GetDecalMeshBoundingSphere(decal.transform.localToWorldMatrix);
-        // update bounding sphere for a single decal
-        public void UpdateCulling(DecalProjectorComponent decal)
+        public void AddDecal(DecalProjectorComponent decal)
-            int cullIndex = decal.CullIndex;
-            m_BoundingSpheres[cullIndex] = CoreUtils.GetDecalMeshBoundingSphere(decal.transform.localToWorldMatrix);
-        }
+			if (decal.CullIndex != DecalProjectorComponent.kInvalidIndex) //do not add the same decal more than once
+				return;
-        public void AddDecal(DecalProjectorComponent d)
-        {
-            if (d.CullIndex != DecalProjectorComponent.kInvalidIndex)
+			// increase array size if no space left
+            if(m_DecalsCount == m_Decals.Length)
-                RemoveDecal(d);
-            }
-            d.CullIndex = m_Decals.Count;
-            m_Decals.Add(d);
-            UpdateCulling();
+				DecalProjectorComponent[] newDecals = new DecalProjectorComponent[m_DecalsCount + kDecalBlockSize];
+				BoundingSphere[] newSpheres = new BoundingSphere[m_DecalsCount + kDecalBlockSize];
+				m_ResultIndices = new int[m_DecalsCount + kDecalBlockSize];
+
+                m_Decals.CopyTo(newDecals, 0);
+				m_BoundingSpheres.CopyTo(newSpheres, 0);
+
+				m_Decals = newDecals;
+				m_BoundingSpheres = newSpheres;
+			}
+
+			m_Decals[m_DecalsCount] = decal;
+			m_Decals[m_DecalsCount].CullIndex = m_DecalsCount;
+			UpdateBoundingSphere(m_Decals[m_DecalsCount]);
+			m_DecalsCount++;            
-        public void RemoveDecal(DecalProjectorComponent d)
+        public void RemoveDecal(DecalProjectorComponent decal)
-            m_Decals.Remove(d);
-            UpdateCulling();
+			if (decal.CullIndex == DecalProjectorComponent.kInvalidIndex) //do not remove decal that has not been added
+				return;
+
+			int removeAtIndex = decal.CullIndex;
+			// replace with last decal in the list and update index
+			m_Decals[removeAtIndex] = m_Decals[m_DecalsCount - 1]; // move the last decal in list 
+			m_Decals[removeAtIndex].CullIndex = removeAtIndex;
+			m_Decals[m_DecalsCount - 1] = null;
+
+			// update the bounding spheres array
+			m_BoundingSpheres[removeAtIndex] = m_BoundingSpheres[m_DecalsCount - 1];
+			m_DecalsCount--;
+			decal.CullIndex = DecalProjectorComponent.kInvalidIndex;
+			m_NumResults = 0;
-            m_CullingGroup.SetBoundingSpheres(m_BoundingSpheres);            
+            m_CullingGroup.SetBoundingSpheres(m_BoundingSpheres);
+			m_CullingGroup.SetBoundingSphereCount(m_DecalsCount);
         }
 
 		public int QueryCullResults()

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipelineAsset.asset

   m_EditorClassIdentifier: 
   m_RenderPipelineResources: {fileID: 11400000, guid: 3ce144cff5783da45aa5d4fdc2da14b7,
     type: 2}
-  defaultFrameSettings:
-    lightingSettings:
-      enableShadow: 1
-      enableSSR: 1
-      enableSSAO: 1
-      enableSSSAndTransmission: 1
-      diffuseGlobalDimmer: 1
-      specularGlobalDimmer: 1
-    renderSettings:
-      enableForwardRenderingOnly: 1
-      enableDepthPrepassWithDeferredRendering: 0
-      enableAlphaTestOnlyInDeferredPrepass: 0
-      enableTransparentPrePass: 1
-      enableMotionVectors: 1
-      enableDBuffer: 1
-      enableAtmosphericScattering: 1
-      enableRoughRefraction: 1
-      enableTransparentPostPass: 1
-      enableDistortion: 1
-      enablePostprocess: 1
-      enableStereo: 0
-      enableAsyncCompute: 0
-      enableOpaqueObjects: 1
-      enableTransparentObjects: 1
-      enableMSAA: 0
-      enableMaterialDisplayDebug: 0
-      enableShadowMask: 0
+  serializedFrameSettings:
+    enableShadow: 1
+    enableSSR: 1
+    enableSSAO: 1
+    enableSSSAndTransmission: 1
+    diffuseGlobalDimmer: 1
+    specularGlobalDimmer: 1
+    enableForwardRenderingOnly: 0
+    enableDepthPrepassWithDeferredRendering: 0
+    enableAlphaTestOnlyInDeferredPrepass: 0
+    enableTransparentPrePass: 1
+    enableMotionVectors: 1
+    enableObjectMotionVectors: 1
+    enableDBuffer: 1
+    enableAtmosphericScattering: 1
+    enableRoughRefraction: 1
+    enableTransparentPostPass: 1
+    enableDistortion: 1
+    enablePostprocess: 1
+    enableStereo: 0
+    enableAsyncCompute: 0
+    enableOpaqueObjects: 1
+    enableTransparentObjects: 1
+    enableMSAA: 0
+    enableShadowMask: 0
     lightLoopSettings:
       enableTileAndCluster: 1
       enableComputeLightEvaluation: 1
       enableBigTilePrepass: 1
       isFptlEnabled: 1
-  m_globalFrameSettings: {fileID: 0}
-  m_sssSettings: {fileID: 0}
+  renderPipelineSettings:
+    supportShadowMask: 1
+    supportSSR: 1
+    supportSSAO: 1
+    supportSSSAndTransmission: 1
+    supportDBuffer: 1
+    supportMSAA: 0
+    supportAsyncCompute: 0
+    lightLoopSettings:
+      spotCookieSize: 128
+      cookieTexArraySize: 16
+      pointCookieSize: 512
+      cubeCookieTexArraySize: 16
+      reflectionProbeCacheSize: 128
+      reflectionCubemapSize: 128
+      reflectionCacheCompressed: 0
+    shadowInitParams:
+      shadowAtlasWidth: 4096
+      shadowAtlasHeight: 4096
+  sssSettings: {fileID: 0}
   m_DefaultDiffuseMaterial: {fileID: 2100000, guid: 73c176f402d2c2f4d929aa5da7585d17,
     type: 2}
   m_DefaultShader: {fileID: 4800000, guid: 6e4ae4064600d784cac1e41a9e6f2e59, type: 3}

ScriptableRenderPipeline/HDRenderPipeline/Material/Decal/DecalData.hlsl

 #endif
 #if _MASKMAP
 	surfaceData.mask = SAMPLE_TEXTURE2D(_MaskMap, sampler_MaskMap, texCoordDS.xy); 
-	surfaceData.normalWS.w *= surfaceData.mask.z;
-	surfaceData.mask.z *= totalBlend;
+	surfaceData.mask.z = totalBlend;
 #endif
 
 }

ScriptableRenderPipeline/HDRenderPipeline/Material/Decal/DecalUtilities.hlsl

 
 void AddDecalContribution(uint2 unPositionSS, inout SurfaceData surfaceData)
 {
-    // Currently disabled
-#if 1
 	FETCH_DBUFFER(DBuffer, _DBufferTexture, unPositionSS);
 	DecalSurfaceData decalSurfaceData;
 	DECODE_FROM_DBUFFER(DBuffer, decalSurfaceData);
 	surfaceData.metallic = lerp(surfaceData.metallic, decalSurfaceData.mask.x, decalSurfaceData.mask.z);
 	surfaceData.ambientOcclusion = lerp(surfaceData.ambientOcclusion, decalSurfaceData.mask.y, decalSurfaceData.mask.z);
 	surfaceData.perceptualSmoothness = lerp(surfaceData.perceptualSmoothness, decalSurfaceData.mask.w, decalSurfaceData.mask.z);
-#endif
 }