adding fb fetch to Gbuffer decals and some other depth related fixes for decals

Author: jonuuukas

com.unity.render-pipelines.universal/Editor/Decal/DecalPass.template

@@ -63,7 +63,10 @@ Pass
     #ifdef SCENEPICKINGPASS
     float4 _SelectionID;
     #endif
-
+    #if _RENDER_PASS_ENABLED
+    #define DEPTH_COPY 0
+    FRAMEBUFFER_INPUT_FLOAT(DEPTH_COPY);
+    #endif
     // Includes
     $splice(PreGraphIncludes)
 

com.unity.render-pipelines.universal/Editor/ShaderGraph/Includes/ShaderPassDecal.hlsl

@@ -181,12 +181,20 @@ void Frag(PackedVaryings packedInput,
 
 #if defined(DECAL_PROJECTOR)
 #if UNITY_REVERSED_Z
+#if _RENDER_PASS_ENABLED
+    float depth = LOAD_FRAMEBUFFER_INPUT(DEPTH_COPY, input.positionCS.xy);
+#else
     float depth = LoadSceneDepth(input.positionCS.xy);
+#endif
+#else
+#if _RENDER_PASS_ENABLED
+    float depth = lerp(UNITY_NEAR_CLIP_VALUE, 1, LOAD_FRAMEBUFFER_INPUT(DEPTH_COPY, input.positionCS.xy));
 #else
     // Adjust z to match NDC for OpenGL
     float depth = lerp(UNITY_NEAR_CLIP_VALUE, 1, LoadSceneDepth(input.positionCS.xy));
 #endif
 #endif
+#endif
 
 #if defined(DECAL_RECONSTRUCT_NORMAL)
     #if defined(_DECAL_NORMAL_BLEND_HIGH)

com.unity.render-pipelines.universal/Editor/ShaderGraph/Targets/UniversalDecalSubTarget.cs

@@ -977,6 +977,7 @@ static class Descriptors
                 { CoreKeywordDescriptors.MixedLightingSubtractive },
                 { Descriptors.DecalsNormalBlend },
                 { CoreKeywordDescriptors.GBufferNormalsOct },
+                { CoreKeywordDescriptors.RenderPassEnabled },
                 { Descriptors.LodCrossFade, new FieldCondition(Fields.LodCrossFade, true) },
             };
 
@@ -986,6 +987,7 @@ static class Descriptors
                 { CoreKeywordDescriptors.ShadowsSoft },
                 { Descriptors.DecalsNormalBlend },
                 { CoreKeywordDescriptors.GBufferNormalsOct },
+                { CoreKeywordDescriptors.RenderPassEnabled },
             };
         }
         #endregion

com.unity.render-pipelines.universal/Runtime/Decal/ScreenSpace/DecalGBufferRenderPass.cs

@@ -17,6 +17,7 @@ internal class DecalGBufferRenderPass : ScriptableRenderPass
         private DecalDrawGBufferSystem m_DrawSystem;
         private DecalScreenSpaceSettings m_Settings;
         private DeferredLights m_DeferredLights;
+        private RenderTargetIdentifier[] m_GbufferAttachments;
 
         public DecalGBufferRenderPass(DecalScreenSpaceSettings settings, DecalDrawGBufferSystem drawSystem)
         {
@@ -41,7 +42,14 @@ internal void Setup(DeferredLights deferredLights)
 
         public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
         {
-            ConfigureTarget(m_DeferredLights.GbufferAttachmentIdentifiers, m_DeferredLights.DepthAttachmentIdentifier);
+            if (m_GbufferAttachments == null)
+                m_GbufferAttachments = new RenderTargetIdentifier[] { m_DeferredLights.GbufferAttachmentIdentifiers[0], m_DeferredLights.GbufferAttachmentIdentifiers[1],
+                    m_DeferredLights.GbufferAttachmentIdentifiers[2], m_DeferredLights.GbufferAttachmentIdentifiers[3] };
+
+            ConfigureTarget(m_GbufferAttachments, m_DeferredLights.DepthAttachmentIdentifier,  m_DeferredLights.GbufferFormats);
+            if (m_DeferredLights.UseRenderPass)
+                ConfigureInputAttachments(m_DeferredLights.DepthCopyTextureIdentifier, false);
+
         }
 
         public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)

com.unity.render-pipelines.universal/Runtime/RendererFeatures/DecalRendererFeature.cs

@@ -476,9 +476,10 @@ public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingD
                             new RenderTargetHandle(m_DBufferRenderPass.cameraDepthTextureIndentifier),
                             new RenderTargetHandle(m_DBufferRenderPass.dBufferDepthIndentifier)
                         );
+
+                        m_CopyDepthPass.CopyToDepth = true;
                     }
                     m_CopyDepthPass.MssaSamples = 1;
-                    m_CopyDepthPass.CopyToDepth = true;
 
                     renderer.EnqueuePass(m_CopyDepthPass);
                     renderer.EnqueuePass(m_DBufferRenderPass);