Merge pull request #1289 from Unity-Technologies/lw/load_store_rt_optimization

Added explicit load and store actions to all SetRenderTarget commands.

ScriptableRenderPipeline/Core/CoreRP/Utilities/CoreUtils.cs

             ClearRenderTarget(cmd, clearFlag, clearColor);
         }
 
+        // Explicit load and store actions
+        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag, Color clearColor)
+        {
+            cmd.SetRenderTarget(buffer, loadAction, storeAction);
+            ClearRenderTarget(cmd, clearFlag, clearColor);
+        }
+
+        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier buffer, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag)
+        {
+            SetRenderTarget(cmd, buffer, loadAction, storeAction, clearFlag, clearColorAllBlack);
+        }
+
+        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderBufferLoadAction colorLoadAction, RenderBufferStoreAction colorStoreAction,
+            RenderTargetIdentifier depthBuffer, RenderBufferLoadAction depthLoadAction, RenderBufferStoreAction depthStoreAction,
+            ClearFlag clearFlag, Color clearColor)
+        {
+            cmd.SetRenderTarget(colorBuffer, colorLoadAction, colorStoreAction, depthBuffer, depthLoadAction, depthStoreAction);
+            ClearRenderTarget(cmd, clearFlag, clearColor);
+        }
+
+        public static void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorBuffer, RenderBufferLoadAction colorLoadAction, RenderBufferStoreAction colorStoreAction,
+            RenderTargetIdentifier depthBuffer, RenderBufferLoadAction depthLoadAction, RenderBufferStoreAction depthStoreAction,
+            ClearFlag clearFlag)
+        {
+            SetRenderTarget(cmd, colorBuffer, colorLoadAction, colorStoreAction, depthBuffer, depthLoadAction, depthStoreAction, clearFlag, clearColorAllBlack);
+        }
+
         public static string GetRenderTargetAutoName(int width, int height, RenderTextureFormat format, string name = "", bool mips = false, bool enableMSAA = false, MSAASamples msaaSamples = MSAASamples.None)
         {
             string temp;

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightPipeline.cs

         private void DepthPass(ref ScriptableRenderContext context, FrameRenderingConfiguration frameRenderingConfiguration)
         {
             CommandBuffer cmd = CommandBufferPool.Get("Depth Prepass");
-            SetRenderTarget(cmd, m_DepthRT, ClearFlag.Depth);
+            SetRenderTarget(cmd, m_DepthRT, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, ClearFlag.Depth);
             context.ExecuteCommandBuffer(cmd);
             CommandBufferPool.Release(cmd);
 
             StopStereoRendering(m_CurrCamera, ref context, frameRenderingConfiguration);
         }
 
-        private void OpaqueTexturePass(ref ScriptableRenderContext context, FrameRenderingConfiguration frameRenderingConfiguration)
+        private void OpaqueTexturePass(ref ScriptableRenderContext context, FrameRenderingConfiguration frameRenderingConfiguration, RenderTargetIdentifier depthRT)
         {
             var opaqueScaler = m_OpaqueScalerValues[(int)m_Asset.OpaqueDownsampling];
             RenderTextureDescriptor opaqueDesc = CreateRTDesc(frameRenderingConfiguration, opaqueScaler);
                     cmd.Blit(m_CurrCameraColorRT, CameraRenderTargetID.opaque);
                     break;
             }
-            SetRenderTarget(cmd, m_CurrCameraColorRT, m_DepthRT);
+            SetRenderTarget(cmd, m_CurrCameraColorRT, depthRT, RenderBufferLoadAction.Load, RenderBufferStoreAction.Store);
             context.ExecuteCommandBuffer(cmd);
             CommandBufferPool.Release(cmd);
         }
 
         private void AfterOpaque(ref ScriptableRenderContext context, FrameRenderingConfiguration config)
         {
+            RenderTargetIdentifier depthRT = m_DepthRT;
+            bool doOpaqueCopy = m_Asset.RequireOpaqueTexture;
             if (m_RequireDepthTexture)
             {
                 CommandBuffer cmd = CommandBufferPool.Get("After Opaque");
-                RenderTargetIdentifier depthRT = m_DepthRT;
 
                 // TODO: There's currently an issue in the PostFX stack that has a one frame delay when an effect is enabled/disabled
                 // when an effect is disabled, HasOpaqueOnlyEffects returns true in the first frame, however inside render the effect
                         RenderPostProcess(cmd, m_CurrCameraColorRT, m_CurrCameraColorRT, true);
 
                     setRenderTarget = true;
-                    SetRenderTarget(cmd, m_CurrCameraColorRT, m_DepthRT);
                 }
 
                 if (CoreUtils.HasFlag(config, FrameRenderingConfiguration.DepthCopy))
                     cmd.SetGlobalTexture(CameraRenderTargetID.depth, m_CopyDepth);
                 }
 
-                if (setRenderTarget)
-                    SetRenderTarget(cmd, m_CurrCameraColorRT, depthRT);
+                if (setRenderTarget && !doOpaqueCopy)
+                    SetRenderTarget(cmd, m_CurrCameraColorRT, depthRT, RenderBufferLoadAction.Load, RenderBufferStoreAction.Store);
-            if (m_Asset.RequireOpaqueTexture)
+            if (doOpaqueCopy)
-                OpaqueTexturePass(ref context, config);
+                OpaqueTexturePass(ref context, config, depthRT);
             }
         }
 
                     clearFlag |= ClearFlag.Color;
             }
 
-            SetRenderTarget(cmd, colorRT, depthRT, clearFlag);
+            SetRenderTarget(cmd, colorRT, depthRT, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, clearFlag);
 
             // If rendering to an intermediate RT we resolve viewport on blit due to offset not being supported
             // while rendering to a RT.
             if (m_IsOffscreenCamera)
                 return;
 
+            bool isStereo = CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.Stereo);
+
-            {
-            }
-            else if (CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.IntermediateTexture))
+            else if (CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.IntermediateTexture) &&
+                !CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.PostProcess))
+            // If PostProcessing is enabled, it is already blit to CameraTarget.
-                Material blitMaterial = m_BlitMaterial;
-                if (CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.Stereo))
-                    blitMaterial = null;
-
-                // If PostProcessing is enabled, it is already blit to CameraTarget.
-                if (!CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.PostProcess))
-                    Blit(cmd, renderingConfig, m_CurrCameraColorRT, BuiltinRenderTextureType.CameraTarget, blitMaterial);
+                Blit(cmd, renderingConfig, m_CurrCameraColorRT, BuiltinRenderTextureType.CameraTarget, isStereo ? null : m_BlitMaterial);
-
-            SetRenderTarget(cmd, BuiltinRenderTextureType.CameraTarget);
+            else
+                SetRenderTarget(cmd, BuiltinRenderTextureType.CameraTarget, RenderBufferLoadAction.Load, RenderBufferStoreAction.Store);
-            if (CoreUtils.HasFlag(renderingConfig, FrameRenderingConfiguration.Stereo))
+            if (isStereo)
             {
                 context.StopMultiEye(m_CurrCamera);
                 context.StereoEndRender(m_CurrCamera);
                 m_CameraPostProcessLayer.Render(m_PostProcessRenderContext);
         }
 
-        private void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorRT, ClearFlag clearFlag = ClearFlag.None)
+        private void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorRT, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag = ClearFlag.None)
-            int depthSlice = (m_IntermediateTextureArray) ? -1 : 0;
-            CoreUtils.SetRenderTarget(cmd, colorRT, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor), 0, CubemapFace.Unknown, depthSlice);
+            if (m_IntermediateTextureArray)
+                CoreUtils.SetRenderTarget(cmd, colorRT, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor), 0, CubemapFace.Unknown, -1);
+            else
+                CoreUtils.SetRenderTarget(cmd, colorRT, loadAction, storeAction, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor));
-        private void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorRT, RenderTargetIdentifier depthRT, ClearFlag clearFlag = ClearFlag.None)
+        private void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorRT, RenderBufferLoadAction colorLoadAction, RenderBufferStoreAction colorStoreAction,
+            RenderTargetIdentifier depthRT, RenderBufferLoadAction depthLoadAction, RenderBufferStoreAction depthStoreAction, ClearFlag clearFlag = ClearFlag.None)
-                SetRenderTarget(cmd, colorRT, clearFlag);
+                SetRenderTarget(cmd, colorRT, colorLoadAction, colorStoreAction, clearFlag);
-            int depthSlice = (m_IntermediateTextureArray) ? -1 : 0;
-            CoreUtils.SetRenderTarget(cmd, colorRT, depthRT, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor), 0, CubemapFace.Unknown, depthSlice);
+            if (m_IntermediateTextureArray)
+                CoreUtils.SetRenderTarget(cmd, colorRT, depthRT, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor), 0, CubemapFace.Unknown, -1);
+            else
+                CoreUtils.SetRenderTarget(cmd, colorRT, colorLoadAction, colorStoreAction, depthRT, depthLoadAction, depthStoreAction, clearFlag, CoreUtils.ConvertSRGBToActiveColorSpace(m_CurrCamera.backgroundColor));
+        }
+
+        private void SetRenderTarget(CommandBuffer cmd, RenderTargetIdentifier colorRT, RenderTargetIdentifier depthRT, RenderBufferLoadAction loadAction, RenderBufferStoreAction storeAction, ClearFlag clearFlag = ClearFlag.None)
+        {
+            SetRenderTarget(cmd, colorRT, loadAction, storeAction, depthRT, loadAction, storeAction, clearFlag);
         }
 
         private void Blit(CommandBuffer cmd, FrameRenderingConfiguration renderingConfig, RenderTargetIdentifier sourceRT, RenderTargetIdentifier destRT, Material material = null)
             {
                 // Viewport doesn't work when rendering to an RT
                 // We have to manually blit by rendering a fullscreen quad
-                SetRenderTarget(cmd, destRT);
+                SetRenderTarget(cmd, destRT, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store);
                 cmd.SetViewProjectionMatrices(Matrix4x4.identity, Matrix4x4.identity);
                 cmd.SetViewport(m_CurrCamera.pixelRect);
                 DrawFullScreen(cmd, m_BlitMaterial);

ScriptableRenderPipeline/LightweightPipeline/LWRP/LightweightShadowPass.cs

             // stereo functionality, we use the screen-space shadow map as the source (until we have
             // a better solution).
             // An alternative would be DrawProcedural, but that would require further changes in the shader.
-            cmd.SetRenderTarget(m_ScreenSpaceShadowmapTexture);
-            cmd.ClearRenderTarget(true, true, Color.white);
+            CoreUtils.SetRenderTarget(cmd, m_ScreenSpaceShadowmapTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, ClearFlag.Color | ClearFlag.Depth, Color.white);
             cmd.Blit(m_ScreenSpaceShadowmapTexture, m_ScreenSpaceShadowmapTexture, m_ScreenSpaceShadowsMaterial);
 
             LightweightPipeline.StartStereoRendering(camera, ref context, frameRenderingConfiguration);
             m_DirectionalShadowmapTexture.filterMode = FilterMode.Bilinear;
             m_DirectionalShadowmapTexture.wrapMode = TextureWrapMode.Clamp;
 
-            CoreUtils.SetRenderTarget(cmd, m_DirectionalShadowmapTexture, ClearFlag.Depth);
+            CoreUtils.SetRenderTarget(cmd, m_DirectionalShadowmapTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, ClearFlag.Depth);
 
             bool success = false;
             for (int cascadeIndex = 0; cascadeIndex < m_ShadowCasterCascadesCount; ++cascadeIndex)
             m_LocalShadowmapTexture.filterMode = FilterMode.Bilinear;
             m_LocalShadowmapTexture.wrapMode = TextureWrapMode.Clamp;
 
-            CoreUtils.SetRenderTarget(cmd, m_LocalShadowmapTexture, ClearFlag.Depth);
+            CoreUtils.SetRenderTarget(cmd, m_LocalShadowmapTexture, RenderBufferLoadAction.DontCare, RenderBufferStoreAction.Store, ClearFlag.Depth);
 
             for (int i = 0; i < localLightsCount; ++i)
             {