Merged with master.

integrated decal group culling with HDRenderPipeline

ScriptableRenderPipeline/HDRenderPipeline/Decal/DecalSystem.cs

         Mesh m_DecalMesh;
         CullingGroup m_CullingGroup;
         private BoundingSphere[] m_BoundingSpheres;
+		private int[] m_ResultIndices;
+		private int m_NumResults = 0;
      
         public DecalSystem()
         {
         void UpdateCulling()
         {
             m_BoundingSpheres = new BoundingSphere[m_Decals.Count];
+			m_ResultIndices = new int[m_Decals.Count];
             int cullIndex = 0;
             foreach (var decal in m_Decals)
             {
             m_CullingGroup.SetBoundingSpheres(m_BoundingSpheres);            
         }
 
+		public int QueryCullResults()
+		{
+			m_NumResults = m_CullingGroup.QueryIndices(true, m_ResultIndices, 0);
+			return m_NumResults;
+		}
+
-            int numResults = 0;
-            int[] resultIndices = new int[m_Decals.Count];
-            numResults = m_CullingGroup.QueryIndices(true, resultIndices, 0);
-
-            for (int resultIndex = 0; resultIndex < numResults; resultIndex++)
+            for (int resultIndex = 0; resultIndex < m_NumResults; resultIndex++)
-                int decalIndex = resultIndices[resultIndex];
+                int decalIndex = m_ResultIndices[resultIndex];
 
                 // If no decal material assigned, don't draw it
                 if (m_Decals[decalIndex].m_Material == null)

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

                     }
 #endif
                     // decal system needs to be updated with current camera
-                    DecalSystem.instance.Cull(camera);
+					if (m_FrameSettings.enableDBuffer)
+						DecalSystem.instance.Cull(camera);
 
                     using (new ProfilingSample(cmd, "CullResults.Cull", GetSampler(CustomSamplerId.CullResultsCull)))
                     {
 
 	                InitAndClearBuffer(hdCamera, enableBakeShadowMask, cmd);
 
-                    RenderDepthPrepass(m_CullResults, hdCamera, renderContext, cmd, true);
+					bool forcePrepassForDecals = m_FrameSettings.enableDBuffer && (DecalSystem.instance.QueryCullResults() > 0);
+                    RenderDepthPrepass(m_CullResults, hdCamera, renderContext, cmd, forcePrepassForDecals);
 
                     RenderObjectsVelocity(m_CullResults, hdCamera, renderContext, cmd);
 

ScriptableRenderPipeline/HDRenderPipeline/Material/Decal/DecalProperties.hlsl

 
 
 TEXTURE2D(_BaseColorMap);
-SAMPLER2D(sampler_BaseColorMap);
+SAMPLER(sampler_BaseColorMap);
-SAMPLER2D(sampler_NormalMap);
+SAMPLER(sampler_NormalMap);
-SAMPLER2D(sampler_MaskMap);
+SAMPLER(sampler_MaskMap);
 
 float _DecalBlend;