From 81612521c8e9bfdf7f3c9753fc870e5d4fa777c6 Mon Sep 17 00:00:00 2001
From: assiduous <assiduous@diligentgraphics.com>
Date: Tue, 31 Oct 2023 20:49:47 -0700
Subject: [PATCH] Hydrogent: moved PS main source to USD renderer

---
 Hydrogent/src/HnRenderDelegate.cpp           | 25 --------------
 Hydrogent/src/Tasks/HnSetupRenderingTask.cpp |  2 +-
 PBR/src/USD_Renderer.cpp                     | 35 +++++++++++++++++++-
 3 files changed, 35 insertions(+), 27 deletions(-)

diff --git a/Hydrogent/src/HnRenderDelegate.cpp b/Hydrogent/src/HnRenderDelegate.cpp
index 1d6a83f3..f05d605f 100644
--- a/Hydrogent/src/HnRenderDelegate.cpp
+++ b/Hydrogent/src/HnRenderDelegate.cpp
@@ -62,29 +62,6 @@ const pxr::TfTokenVector HnRenderDelegate::SupportedBPrimTypes =
 };
 // clang-format on
 
-static std::string GetPbrPSMainSource(USD_Renderer::PSO_FLAGS PSOFlags)
-{
-    VERIFY(PSOFlags & USD_Renderer::PSO_FLAG_ENABLE_CUSTOM_DATA_OUTPUT, "Custom output flag is expected to be set");
-    return R"(
-struct PSOutput
-{
-    float4 Color      : SV_Target0;
-    float4 MeshID     : SV_Target1;
-    float4 IsSelected : SV_Target2;
-};
-
-void main(in VSOutput VSOut,
-          in bool IsFrontFace : SV_IsFrontFace,
-          out PSOutput PSOut)
-{
-    PSOut.Color = ComputePbrSurfaceColor(VSOut, IsFrontFace);
-
-    // It is important to set alpha to 1.0 as all targets are rendered with the same blend mode
-    PSOut.MeshID     = float4(g_PBRAttribs.Renderer.CustomData.x, 0.0, 0.0, 1.0);
-    PSOut.IsSelected = float4(g_PBRAttribs.Renderer.CustomData.y, 0.0, 0.0, 1.0);
-}
-)";
-}
 
 HnRenderDelegate::HnRenderDelegate(const CreateInfo& CI) :
     m_pDevice{CI.pDevice},
@@ -118,8 +95,6 @@ HnRenderDelegate::HnRenderDelegate(const CreateInfo& CI) :
                 USDRendererCI.InputLayout.LayoutElements = Inputs;
                 USDRendererCI.InputLayout.NumElements    = _countof(Inputs);
 
-                USDRendererCI.GetPSMainSource = GetPbrPSMainSource;
-
                 return USDRendererCI;
             }()),
     },
diff --git a/Hydrogent/src/Tasks/HnSetupRenderingTask.cpp b/Hydrogent/src/Tasks/HnSetupRenderingTask.cpp
index c174c965..5f026599 100644
--- a/Hydrogent/src/Tasks/HnSetupRenderingTask.cpp
+++ b/Hydrogent/src/Tasks/HnSetupRenderingTask.cpp
@@ -216,7 +216,7 @@ void HnSetupRenderingTask::Execute(pxr::HdTaskContext* TaskCtx)
     auto* pCtx = static_cast<HnRenderDelegate*>(m_RenderIndex->GetRenderDelegate())->GetDeviceContext();
 
     pCtx->SetRenderTargets(_countof(pRTVs), pRTVs, Targets.DepthDSV, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
-    pCtx->ClearRenderTarget(Targets.FinalColorRTV, m_ClearColor.Data(), RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
+    pCtx->ClearRenderTarget(Targets.OffscreenColorRTV, m_ClearColor.Data(), RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
     constexpr float Zero[] = {0, 0, 0, 0};
     pCtx->ClearRenderTarget(Targets.MeshIdRTV, Zero, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
     pCtx->ClearRenderTarget(Targets.SelectionRTV, Zero, RESOURCE_STATE_TRANSITION_MODE_TRANSITION);
diff --git a/PBR/src/USD_Renderer.cpp b/PBR/src/USD_Renderer.cpp
index 8a4ce25b..ac5db349 100644
--- a/PBR/src/USD_Renderer.cpp
+++ b/PBR/src/USD_Renderer.cpp
@@ -33,11 +33,44 @@
 namespace Diligent
 {
 
+static std::string GetUsdPbrPSMainSource(USD_Renderer::PSO_FLAGS PSOFlags)
+{
+    VERIFY(PSOFlags & USD_Renderer::PSO_FLAG_ENABLE_CUSTOM_DATA_OUTPUT, "Custom output flag is expected to be set");
+    return R"(
+struct PSOutput
+{
+    float4 Color      : SV_Target0;
+    float4 MeshID     : SV_Target1;
+    float4 IsSelected : SV_Target2;
+};
+
+void main(in VSOutput VSOut,
+          in bool IsFrontFace : SV_IsFrontFace,
+          out PSOutput PSOut)
+{
+    PSOut.Color = ComputePbrSurfaceColor(VSOut, IsFrontFace);
+
+    // It is important to set alpha to 1.0 as all targets are rendered with the same blend mode
+    PSOut.MeshID     = float4(g_PBRAttribs.Renderer.CustomData.x, 0.0, 0.0, 1.0);
+    PSOut.IsSelected = float4(g_PBRAttribs.Renderer.CustomData.y, 0.0, 0.0, 1.0);
+}
+)";
+}
+
 USD_Renderer::USD_Renderer(IRenderDevice*     pDevice,
                            IRenderStateCache* pStateCache,
                            IDeviceContext*    pCtx,
                            const CreateInfo&  CI) :
-    PBR_Renderer{pDevice, pStateCache, pCtx, CI}
+    PBR_Renderer{
+        pDevice,
+        pStateCache,
+        pCtx,
+        [](CreateInfo CI) {
+            if (CI.GetPSMainSource == nullptr)
+                CI.GetPSMainSource = GetUsdPbrPSMainSource;
+            return CI;
+        }(CI),
+    }
 {
 }