// Copyright 1998-2019 Epic Games, Inc. All Rights Reserved.

/*=============================================================================
	PostProcessMaterial.cpp: Post processing Material implementation.
=============================================================================*/

#include "PostProcess/PostProcessMaterial.h"
#include "RendererModule.h"
#include "Materials/Material.h"
#include "MaterialShaderType.h"
#include "MaterialShader.h"
#include "SceneUtils.h"
#include "PostProcess/SceneRenderTargets.h"
#include "PostProcess/SceneFilterRendering.h"
#include "SceneRendering.h"
#include "ClearQuad.h"
#include "Materials/MaterialExpressionSceneTexture.h"
#include "RHI/Public/PipelineStateCache.h"
#include "PostProcessing.h"
#include "PostProcessMobile.h"
#include "BufferVisualizationData.h"

namespace
{

TAutoConsoleVariable<int32> CVarPostProcessAllowStencilTest(
	TEXT("r.PostProcessAllowStencilTest"),
	1,
	TEXT("Enables stencil testing in post process materials.\n")
	TEXT("0: disable stencil testing\n")
	TEXT("1: allow stencil testing\n")
	);

TAutoConsoleVariable<int32> CVarPostProcessAllowBlendModes(
	TEXT("r.PostProcessAllowBlendModes"),
	1,
	TEXT("Enables blend modes in post process materials.\n")
	TEXT("0: disable blend modes. Uses replace\n")
	TEXT("1: allow blend modes\n")
	);

TAutoConsoleVariable<int32> CVarPostProcessingDisableMaterials(
	TEXT("r.PostProcessing.DisableMaterials"),
	0,
	TEXT(" Allows to disable post process materials. \n"),
	ECVF_Scalability | ECVF_RenderThreadSafe);

bool IsPostProcessStencilTestAllowed()
{
	return CVarPostProcessAllowStencilTest.GetValueOnRenderThread() != 0;
}

bool IsCustomDepthEnabled()
{
	static const IConsoleVariable* CVarCustomDepth = IConsoleManager::Get().FindConsoleVariable(TEXT("r.CustomDepth"));

	check(CVarCustomDepth);

	return CVarCustomDepth->GetInt() == 3;
}

enum class ECustomDepthPolicy : uint32
{
	// Custom depth is disabled.
	Disabled,

	// Custom Depth-Stencil is enabled; potentially simultaneous SRV / DSV usage.
	Enabled
};

ECustomDepthPolicy GetMaterialCustomDepthPolicy(const FMaterial* Material, ERHIFeatureLevel::Type FeatureLevel)
{
	check(Material);

	// Material requesting stencil test and post processing CVar allows it.
	if (Material->IsStencilTestEnabled() && IsPostProcessStencilTestAllowed())
	{
		// Custom stencil texture allocated and available.
		if (IsCustomDepthEnabled())
		{
			return ECustomDepthPolicy::Enabled;
		}
		else
		{
			UE_LOG(LogRenderer, Warning, TEXT("PostProcessMaterial uses stencil test, but stencil not allocated. Set r.CustomDepth to 3 to allocate custom stencil."));
		}
	}

	return ECustomDepthPolicy::Disabled;
}

void GetMaterialInfo(
	const UMaterialInterface* InMaterialInterface,
	ERHIFeatureLevel::Type InFeatureLevel,
	EPixelFormat InOutputFormat,
	const FMaterial*& OutMaterial,
	const FMaterialRenderProxy*& OutMaterialProxy,
	const FMaterialShaderMap*& OutMaterialShaderMap)
{
	const FMaterialRenderProxy* MaterialProxy = InMaterialInterface->GetRenderProxy();
	check(MaterialProxy);

	const FMaterial* Material = MaterialProxy->GetMaterialNoFallback(InFeatureLevel);

	if (!Material || Material->GetMaterialDomain() != MD_PostProcess || !Material->GetRenderingThreadShaderMap())
	{
		// Fallback to the default post process material.
		const UMaterialInterface* DefaultMaterial = UMaterial::GetDefaultMaterial(MD_PostProcess);
		check(DefaultMaterial);
		check(DefaultMaterial != InMaterialInterface);

		return GetMaterialInfo(
			DefaultMaterial,
			InFeatureLevel,
			InOutputFormat,
			OutMaterial,
			OutMaterialProxy,
			OutMaterialShaderMap);
	}

	if (Material->IsStencilTestEnabled() || Material->GetBlendableOutputAlpha())
	{
		// Only allowed to have blend/stencil test if output format is compatible with ePId_Input0. 
		// PF_Unknown implies output format is that of EPId_Input0
		ensure(InOutputFormat == PF_Unknown);
	}

	const FMaterialShaderMap* MaterialShaderMap = Material->GetRenderingThreadShaderMap();;
	check(MaterialShaderMap);

	OutMaterial = Material;
	OutMaterialProxy = MaterialProxy;
	OutMaterialShaderMap = MaterialShaderMap;
}

FRHIDepthStencilState* GetMaterialStencilState(const FMaterial* Material)
{
	static FRHIDepthStencilState* StencilStates[] =
	{
		TStaticDepthStencilState<false, CF_Always, true, CF_Less>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_LessEqual>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_Greater>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_GreaterEqual>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_Equal>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_NotEqual>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_Never>::GetRHI(),
		TStaticDepthStencilState<false, CF_Always, true, CF_Always>::GetRHI(),
	};
	static_assert(EMaterialStencilCompare::MSC_Count == UE_ARRAY_COUNT(StencilStates), "Ensure that all EMaterialStencilCompare values are accounted for.");

	check(Material);

	return StencilStates[Material->GetStencilCompare()];
}

bool IsMaterialBlendEnabled(const FMaterial* Material)
{
	check(Material);

	return Material->GetBlendableOutputAlpha() && CVarPostProcessAllowBlendModes.GetValueOnRenderThread() != 0;
}

FRHIBlendState* GetMaterialBlendState(const FMaterial* Material)
{
	static FRHIBlendState* BlendStates[] =
	{
		TStaticBlendState<>::GetRHI(),
		TStaticBlendState<>::GetRHI(),
		TStaticBlendState<CW_RGB, BO_Add, BF_SourceAlpha, BF_InverseSourceAlpha, BO_Add, BF_Zero, BF_One>::GetRHI(),
		TStaticBlendState<CW_RGB, BO_Add, BF_One, BF_One>::GetRHI(),
		TStaticBlendState<CW_RGB, BO_Add, BF_DestColor, BF_Zero>::GetRHI(),
		TStaticBlendState<CW_RGBA, BO_Add, BF_One, BF_InverseSourceAlpha, BO_Add, BF_One, BF_InverseSourceAlpha>::GetRHI(),
		TStaticBlendState<CW_RGBA, BO_Add, BF_Zero, BF_InverseSourceAlpha, BO_Add, BF_Zero, BF_InverseSourceAlpha>::GetRHI(),
	};
	static_assert(EBlendMode::BLEND_MAX == UE_ARRAY_COUNT(BlendStates), "Ensure that all EBlendMode values are accounted for.");

	check(Material);

	return BlendStates[Material->GetBlendMode()];
}

class FPostProcessMaterialShader : public FMaterialShader
{
public:
	using FParameters = FPostProcessMaterialParameters;
	SHADER_USE_PARAMETER_STRUCT_WITH_LEGACY_BASE(FPostProcessMaterialShader, FMaterialShader);

	class FMobileDimension : SHADER_PERMUTATION_BOOL("POST_PROCESS_MATERIAL_MOBILE");
	using FPermutationDomain = TShaderPermutationDomain<FMobileDimension>;

	static bool ShouldCompilePermutation(const FMaterialShaderPermutationParameters& Parameters)
	{
		if (Parameters.Material->GetMaterialDomain() == MD_PostProcess)
		{
			const FPermutationDomain PermutationVector(Parameters.PermutationId);

			if (PermutationVector.Get<FMobileDimension>())
			{
				return IsMobilePlatform(Parameters.Platform) && IsMobileHDR();
			}
			else
			{
				return IsFeatureLevelSupported(Parameters.Platform, ERHIFeatureLevel::SM5);
			}
		}
		return false;
	}

	static void ModifyCompilationEnvironment(const FMaterialShaderPermutationParameters& Parameters, FShaderCompilerEnvironment& OutEnvironment)
	{
		FMaterialShader::ModifyCompilationEnvironment(Parameters, OutEnvironment);
		OutEnvironment.SetDefine(TEXT("POST_PROCESS_MATERIAL"), 1);

		EBlendableLocation Location = EBlendableLocation(Parameters.Material->GetBlendableLocation());
		OutEnvironment.SetDefine(TEXT("POST_PROCESS_MATERIAL_BEFORE_TONEMAP"), (Location == BL_AfterTonemapping || Location == BL_ReplacingTonemapper) ? 0 : 1);

		FPermutationDomain PermutationVector(Parameters.PermutationId);
		if (PermutationVector.Get<FMobileDimension>())
		{
			OutEnvironment.SetDefine(TEXT("POST_PROCESS_MATERIAL_BEFORE_TONEMAP"), (Parameters.Material->GetBlendableLocation() != BL_AfterTonemapping) ? 1 : 0);
		}
	}

protected:
	template <typename TRHIShader>
	void SetParameters(FRHICommandList& RHICmdList, TRHIShader* ShaderRHI, const FViewInfo& View, const FMaterialRenderProxy* Proxy, const FParameters& Parameters)
	{
		FMaterialShader::SetParameters(RHICmdList, ShaderRHI, Proxy, *Proxy->GetMaterial(View.GetFeatureLevel()), View, View.ViewUniformBuffer, ESceneTextureSetupMode::All);
		SetShaderParameters(RHICmdList, this, ShaderRHI, Parameters);
	}
};

class FPostProcessMaterialVS : public FPostProcessMaterialShader
{
public:
	DECLARE_MATERIAL_SHADER(FPostProcessMaterialVS);

	void SetParameters(FRHICommandList& RHICmdList, const FViewInfo& View, const FMaterialRenderProxy* Proxy, const FParameters& Parameters)
	{
		FPostProcessMaterialShader::SetParameters(RHICmdList, GetVertexShader(), View, Proxy, Parameters);
	}

	FPostProcessMaterialVS() = default;
	FPostProcessMaterialVS(const ShaderMetaType::CompiledShaderInitializerType& Initializer)
		: FPostProcessMaterialShader(Initializer)
	{}
};

class FPostProcessMaterialPS : public FPostProcessMaterialShader
{
public:
	DECLARE_MATERIAL_SHADER(FPostProcessMaterialPS);

	void SetParameters(FRHICommandList& RHICmdList, const FViewInfo& View, const FMaterialRenderProxy* Proxy, const FParameters& Parameters)
	{
		FPostProcessMaterialShader::SetParameters(RHICmdList, GetPixelShader(), View, Proxy, Parameters);
	}

	FPostProcessMaterialPS() = default;
	FPostProcessMaterialPS(const ShaderMetaType::CompiledShaderInitializerType& Initializer)
		: FPostProcessMaterialShader(Initializer)
	{}
};

IMPLEMENT_MATERIAL_SHADER(FPostProcessMaterialVS, "/Engine/Private/PostProcessMaterialShaders.usf", "MainVS", SF_Vertex);
IMPLEMENT_MATERIAL_SHADER(FPostProcessMaterialPS, "/Engine/Private/PostProcessMaterialShaders.usf", "MainPS", SF_Pixel);

class FPostProcessMaterialVertexDeclaration : public FRenderResource
{
public:
	FVertexDeclarationRHIRef VertexDeclarationRHI;

	void InitRHI() override
	{
		FVertexDeclarationElementList Elements;
		uint32 Stride = sizeof(FFilterVertex);
		Elements.Add(FVertexElement(0, STRUCT_OFFSET(FFilterVertex, Position), VET_Float4, 0, Stride));
		VertexDeclarationRHI = PipelineStateCache::GetOrCreateVertexDeclaration(Elements);
	}

	void ReleaseRHI() override
	{
		VertexDeclarationRHI.SafeRelease();
	}
};

TGlobalResource<FPostProcessMaterialVertexDeclaration> GPostProcessMaterialVertexDeclaration;

} //! namespace

FScreenPassTexture AddPostProcessMaterialPass(
	FRDGBuilder& GraphBuilder,
	const FViewInfo& View,
	const FPostProcessMaterialInputs& Inputs,
	const UMaterialInterface* MaterialInterface)
{
	Inputs.Validate();

	const FScreenPassTexture SceneColor = Inputs.GetInput(EPostProcessMaterialInput::SceneColor);

	const ERHIFeatureLevel::Type FeatureLevel = View.GetFeatureLevel();

	const FMaterial* Material = nullptr;
	const FMaterialRenderProxy* MaterialRenderProxy = nullptr;
	const FMaterialShaderMap* MaterialShaderMap = nullptr;
	GetMaterialInfo(MaterialInterface, FeatureLevel, Inputs.OutputFormat, Material, MaterialRenderProxy, MaterialShaderMap);

	FRHIDepthStencilState* DefaultDepthStencilState = FScreenPassPipelineState::FDefaultDepthStencilState::GetRHI();
	FRHIDepthStencilState* DepthStencilState = DefaultDepthStencilState;

	FRDGTextureRef DepthStencilTexture = nullptr;

	// Allocate custom depth stencil texture(s) and depth stencil state.
	const ECustomDepthPolicy CustomStencilPolicy = GetMaterialCustomDepthPolicy(Material, FeatureLevel);

	if (CustomStencilPolicy == ECustomDepthPolicy::Enabled)
	{
		check(Inputs.CustomDepthTexture);
		DepthStencilTexture = Inputs.CustomDepthTexture;
		DepthStencilState = GetMaterialStencilState(Material);
	}

	FRHIBlendState* DefaultBlendState = FScreenPassPipelineState::FDefaultBlendState::GetRHI();
	FRHIBlendState* BlendState = GetMaterialBlendState(Material);

	// Blend / Depth Stencil usage requires that the render target have primed color data.
	const bool bIsCompositeWithInput = DepthStencilState != DefaultDepthStencilState || BlendState != DefaultBlendState;

	// We only prime color on the output texture if we are using fixed function Blend / Depth-Stencil,
	// or we need to retain previously rendered views.
	const bool bPrimeOutputColor = bIsCompositeWithInput || !View.IsFirstInFamily();

	FScreenPassRenderTarget Output = Inputs.OverrideOutput;

	// We can re-use the scene color texture as the render target if we're not simultaneously reading from it.
	// This is only necessary to do if we're going to be priming content from the render target since it avoids
	// the copy. Otherwise, we just allocate a new render target.
	if (!Output.IsValid() && !MaterialShaderMap->UsesSceneTexture(PPI_PostProcessInput0) && bPrimeOutputColor)
	{
		Output = FScreenPassRenderTarget(SceneColor, ERenderTargetLoadAction::ELoad);
	}
	else
	{
		// Allocate new transient output texture if none exists.
		if (!Output.IsValid())
		{
			FRDGTextureDesc OutputDesc = SceneColor.Texture->Desc;
			OutputDesc.Reset();
			if (Inputs.OutputFormat != PF_Unknown)
			{
				OutputDesc.Format = Inputs.OutputFormat;
			}
			OutputDesc.ClearValue = FClearValueBinding(FLinearColor::Black);
			OutputDesc.Flags |= GFastVRamConfig.PostProcessMaterial;

			Output = FScreenPassRenderTarget(GraphBuilder.CreateTexture(OutputDesc, TEXT("PostProcessMaterial")), SceneColor.ViewRect, View.GetOverwriteLoadAction());
		}

		if (bPrimeOutputColor)
		{
			// Copy existing contents to new output and use load-action to preserve untouched pixels.
			AddDrawTexturePass(GraphBuilder, View, SceneColor.Texture, Output.Texture);
			Output.LoadAction = ERenderTargetLoadAction::ELoad;
		}
	}

	const FScreenPassTextureViewport SceneColorViewport(SceneColor);
	const FScreenPassTextureViewport OutputViewport(Output);

	RDG_EVENT_SCOPE(GraphBuilder, "PostProcessMaterial %dx%d Material=%s", SceneColorViewport.Rect.Width(), SceneColorViewport.Rect.Height(), *Material->GetFriendlyName());

	FPostProcessMaterialParameters* PostProcessMaterialParameters = GraphBuilder.AllocParameters<FPostProcessMaterialParameters>();

	PostProcessMaterialParameters->PostProcessOutput = GetScreenPassTextureViewportParameters(SceneColorViewport);
	PostProcessMaterialParameters->CustomDepth = DepthStencilTexture;
	PostProcessMaterialParameters->RenderTargets[0] = Output.GetRenderTargetBinding();

	if (DepthStencilTexture)
	{
		PostProcessMaterialParameters->RenderTargets.DepthStencil = FDepthStencilBinding(
			DepthStencilTexture,
			ERenderTargetLoadAction::ELoad,
			ERenderTargetLoadAction::ELoad,
			FExclusiveDepthStencil::DepthRead_StencilRead);
	}

	PostProcessMaterialParameters->PostProcessInput_BilinearSampler = TStaticSamplerState<SF_Bilinear, AM_Clamp, AM_Clamp, AM_Clamp>::GetRHI();;

	const FScreenPassTexture BlackDummy(GSystemTextures.GetBlackDummy(GraphBuilder));

    // This gets passed in whether or not it's used.
	GraphBuilder.RemoveUnusedTextureWarning(BlackDummy.Texture);

	FRHISamplerState* PointClampSampler = TStaticSamplerState<SF_Point, AM_Clamp, AM_Clamp, AM_Clamp>::GetRHI();

	for (uint32 InputIndex = 0; InputIndex < kPostProcessMaterialInputCountMax; ++InputIndex)
	{
		FScreenPassTexture Input = Inputs.GetInput((EPostProcessMaterialInput)InputIndex);

		// Need to provide valid textures for when shader compilation doesn't cull unused parameters.
		if (!Input.Texture || !MaterialShaderMap->UsesSceneTexture(PPI_PostProcessInput0 + InputIndex))
		{
			Input = BlackDummy;
		}

		PostProcessMaterialParameters->PostProcessInput[InputIndex] = GetScreenPassTextureInput(Input, PointClampSampler);
	}

	const bool bIsMobile = FeatureLevel <= ERHIFeatureLevel::ES3_1;

	PostProcessMaterialParameters->bFlipYAxis = Inputs.bFlipYAxis;

	FPostProcessMaterialShader::FPermutationDomain PermutationVector;
	PermutationVector.Set<FPostProcessMaterialShader::FMobileDimension>(bIsMobile);

	FPostProcessMaterialVS* VertexShader = MaterialShaderMap->GetShader<FPostProcessMaterialVS>(PermutationVector);
	FPostProcessMaterialPS* PixelShader = MaterialShaderMap->GetShader<FPostProcessMaterialPS>(PermutationVector);

	const uint32 MaterialStencilRef = Material->GetStencilRefValue();

	EScreenPassDrawFlags ScreenPassFlags = EScreenPassDrawFlags::AllowHMDHiddenAreaMask;

	if (Inputs.bFlipYAxis)
	{
		ScreenPassFlags |= EScreenPassDrawFlags::FlipYAxis;
	}

	const bool bNeedsGBuffer = Material->NeedsGBuffer();

	if (bNeedsGBuffer)
	{
		FSceneRenderTargets::Get(GraphBuilder.RHICmdList).AdjustGBufferRefCount(GraphBuilder.RHICmdList, 1);
	}

	GraphBuilder.AddPass(
		RDG_EVENT_NAME("PostProcessMaterial"),
		PostProcessMaterialParameters,
		ERDGPassFlags::Raster,
		[&View, OutputViewport, SceneColorViewport, VertexShader, PixelShader, BlendState, DepthStencilState, ScreenPassFlags, MaterialRenderProxy, PostProcessMaterialParameters, MaterialStencilRef, bNeedsGBuffer] (FRHICommandListImmediate& RHICmdList)
	{
		DrawScreenPass(
			RHICmdList,
			View,
			OutputViewport,
			SceneColorViewport,
			FScreenPassPipelineState(VertexShader, PixelShader, BlendState, DepthStencilState),
			ScreenPassFlags,
			[&](FRHICommandListImmediate&)
		{
			VertexShader->SetParameters(RHICmdList, View, MaterialRenderProxy, *PostProcessMaterialParameters);
			PixelShader->SetParameters(RHICmdList, View, MaterialRenderProxy, *PostProcessMaterialParameters);
			RHICmdList.SetStencilRef(MaterialStencilRef);
		});

		if (bNeedsGBuffer)
		{
			FSceneRenderTargets::Get(RHICmdList).AdjustGBufferRefCount(RHICmdList, -1);
		}
	});

	return MoveTemp(Output);
}

static bool IsPostProcessMaterialsEnabledForView(const FViewInfo& View)
{
	if (!View.Family->EngineShowFlags.PostProcessing ||
		!View.Family->EngineShowFlags.PostProcessMaterial ||
		View.Family->EngineShowFlags.VisualizeShadingModels ||
		CVarPostProcessingDisableMaterials.GetValueOnRenderThread() != 0)
	{
		return false;
	}

	return true;
}

static FPostProcessMaterialNode* IteratePostProcessMaterialNodes(const FFinalPostProcessSettings& Dest, EBlendableLocation Location, FBlendableEntry*& Iterator)
{
	for (;;)
	{
		FPostProcessMaterialNode* DataPtr = Dest.BlendableManager.IterateBlendables<FPostProcessMaterialNode>(Iterator);

		if (!DataPtr || DataPtr->GetLocation() == Location)
		{
			return DataPtr;
		}
	}
}

FPostProcessMaterialChain GetPostProcessMaterialChain(const FViewInfo& View, EBlendableLocation Location)
{
	if (!IsPostProcessMaterialsEnabledForView(View))
	{
		return {};
	}

	const FSceneViewFamily& ViewFamily = *View.Family;

	TArray<FPostProcessMaterialNode, TInlineAllocator<10>> Nodes;
	FBlendableEntry* Iterator = nullptr;

	if (ViewFamily.EngineShowFlags.VisualizeBuffer)
	{
		UMaterial* Material = GetBufferVisualizationData().GetMaterial(View.CurrentBufferVisualizationMode);

		if (Material && Material->BlendableLocation == Location)
		{
			Nodes.Add(FPostProcessMaterialNode(Material, Location, Material->BlendablePriority));
		}
	}

	while (FPostProcessMaterialNode* Data = IteratePostProcessMaterialNodes(View.FinalPostProcessSettings, Location, Iterator))
	{
		check(Data->GetMaterialInterface());
		Nodes.Add(*Data);
	}

	if (!Nodes.Num())
	{
		return {};
	}

	::Sort(Nodes.GetData(), Nodes.Num(), FPostProcessMaterialNode::FCompare());

	FPostProcessMaterialChain OutputChain;
	OutputChain.Reserve(Nodes.Num());

	for (const FPostProcessMaterialNode& Node : Nodes)
	{
		OutputChain.Add(Node.GetMaterialInterface());
	}

	return OutputChain;
}

FScreenPassTexture AddPostProcessMaterialChain(
	FRDGBuilder& GraphBuilder,
	const FViewInfo& View,
	const FPostProcessMaterialInputs& InputsTemplate,
	const FPostProcessMaterialChain& Materials)
{
	FScreenPassTexture Outputs = InputsTemplate.GetInput(EPostProcessMaterialInput::SceneColor);

	for (const UMaterialInterface* MaterialInterface : Materials)
	{
		FPostProcessMaterialInputs Inputs = InputsTemplate;
		Inputs.SetInput(EPostProcessMaterialInput::SceneColor, Outputs);

		// Certain inputs are only respected by the final post process material in the chain.
		if (MaterialInterface != Materials.Last())
		{
			Inputs.OverrideOutput = FScreenPassRenderTarget();
			Inputs.bFlipYAxis = false;
		}

		Outputs = AddPostProcessMaterialPass(GraphBuilder, View, Inputs, MaterialInterface);
	}

	return Outputs;
}

FRenderingCompositePass* AddPostProcessMaterialPass(
	const FPostprocessContext& PostProcessContext,
	const UMaterialInterface* MaterialInterface,
	EPixelFormat OverrideOutputFormat)
{
	const FMaterial* Material = nullptr;

	{
		const FMaterialRenderProxy* MaterialRenderProxy = nullptr;
		const FMaterialShaderMap* MaterialShaderMap = nullptr;
		GetMaterialInfo(MaterialInterface, PostProcessContext.View.GetFeatureLevel(), OverrideOutputFormat, Material, MaterialRenderProxy, MaterialShaderMap);
		check(Material);
	}

	if (Material->NeedsGBuffer())
	{
		FSceneRenderTargets::Get(PostProcessContext.RHICmdList).AdjustGBufferRefCount(PostProcessContext.RHICmdList, 1);
	}

	return PostProcessContext.Graph.RegisterPass(new(FMemStack::Get()) TRCPassForRDG<kPostProcessMaterialInputCountMax, 1>(
		[MaterialInterface, Material, OverrideOutputFormat](FRenderingCompositePass* Pass, FRenderingCompositePassContext& InContext)
	{
		FRDGBuilder GraphBuilder(InContext.RHICmdList);

		FPostProcessMaterialInputs Inputs;
		Inputs.OutputFormat = OverrideOutputFormat;

		// Either finds the overridden frame buffer target or returns null.
		if (FRDGTextureRef OutputTexture = Pass->FindRDGTextureForOutput(GraphBuilder, ePId_Output0, TEXT("FrameBufferOverride")))
		{
			Inputs.OverrideOutput.Texture = OutputTexture;
			Inputs.OverrideOutput.ViewRect = InContext.GetSceneColorDestRect(Pass);
			Inputs.OverrideOutput.LoadAction = InContext.View.IsFirstInFamily() ? ERenderTargetLoadAction::EClear : ERenderTargetLoadAction::ELoad;
		}

		for (uint32 InputIndex = 0; InputIndex < kPostProcessMaterialInputCountMax; ++InputIndex)
		{
			FRDGTextureRef InputTexture = Pass->CreateRDGTextureForOptionalInput(GraphBuilder, EPassInputId(InputIndex), TEXT("PostProcessInput"));

			/**
			 * TODO: Propagate each texture viewport through the graph setup instead of guessing. This is wrong for
			 * any scaled target (e.g. half resolution bloom). We deal with the upsample from TAAU explicitly here,
			 * but it's a band-aid at best. The problem is that we rely too heavily on the ViewRect--in pixels--which
			 * only applies to the primary screen resolution viewport.
			 */
			const FIntRect InputViewportRect = (InputIndex == 0) ? InContext.SceneColorViewRect : InContext.View.ViewRect;

			Inputs.SetInput((EPostProcessMaterialInput)InputIndex, FScreenPassTexture(InputTexture, InputViewportRect));
		}

		Inputs.bFlipYAxis = ShouldMobilePassFlipVerticalAxis(Pass);

		if (TRefCountPtr<IPooledRenderTarget> CustomDepthTarget = FSceneRenderTargets::Get(InContext.RHICmdList).CustomDepth)
		{
			Inputs.CustomDepthTexture = GraphBuilder.RegisterExternalTexture(CustomDepthTarget, TEXT("CustomDepth"));
		}

		FScreenPassTexture Outputs = AddPostProcessMaterialPass(GraphBuilder, InContext.View, Inputs, MaterialInterface);

		Pass->ExtractRDGTextureForOutput(GraphBuilder, ePId_Output0, Outputs.Texture);

		GraphBuilder.Execute();

		if (Material->NeedsGBuffer())
		{
			FSceneRenderTargets::Get(InContext.RHICmdList).AdjustGBufferRefCount(InContext.RHICmdList, -1);
		}
	}));
}

FRenderingCompositeOutputRef AddPostProcessMaterialChain(
	FPostprocessContext& Context,
	EBlendableLocation Location,
	FRenderingCompositeOutputRef SeparateTranslucency,
	FRenderingCompositeOutputRef PreTonemapHDRColor,
	FRenderingCompositeOutputRef PostTonemapHDRColor,
	FRenderingCompositeOutputRef PreFlattenVelocity)
{
	const FPostProcessMaterialChain MaterialChain = GetPostProcessMaterialChain(Context.View, Location);

	ERHIFeatureLevel::Type FeatureLevel = Context.View.GetFeatureLevel();

	FRenderingCompositeOutputRef LastOutput = Context.FinalOutput;

	for (const UMaterialInterface* MaterialInterface : MaterialChain)
	{
		FRenderingCompositePass* Pass = AddPostProcessMaterialPass(Context, MaterialInterface);

		Pass->SetInput(EPassInputId(EPostProcessMaterialInput::SceneColor), LastOutput);
		Pass->SetInput(EPassInputId(EPostProcessMaterialInput::SeparateTranslucency), SeparateTranslucency);
		Pass->SetInput(EPassInputId(EPostProcessMaterialInput::PreTonemapHDRColor), PreTonemapHDRColor);
		Pass->SetInput(EPassInputId(EPostProcessMaterialInput::PostTonemapHDRColor), PostTonemapHDRColor);

		if (!FVelocityRendering::BasePassCanOutputVelocity(FeatureLevel))
		{
			Pass->SetInput(EPassInputId(EPostProcessMaterialInput::Velocity), PreFlattenVelocity);
		}

		LastOutput = FRenderingCompositeOutputRef(Pass);
	}

	return LastOutput;
}

extern void AddDumpToColorArrayPass(FRDGBuilder& GraphBuilder, FScreenPassTexture Input, TArray<FColor>* OutputColorArray);

bool IsHighResolutionScreenshotMaskEnabled(const FViewInfo& View)
{
	return View.Family->EngineShowFlags.HighResScreenshotMask || View.FinalPostProcessSettings.HighResScreenshotCaptureRegionMaterial;
}

FScreenPassTexture AddHighResolutionScreenshotMaskPass(
	FRDGBuilder& GraphBuilder,
	const FViewInfo& View,
	const FHighResolutionScreenshotMaskInputs& Inputs)
{
	check(Inputs.Material || Inputs.MaskMaterial || Inputs.CaptureRegionMaterial);

	enum class EPass
	{
		Material,
		MaskMaterial,
		CaptureRegionMaterial,
		MAX
	};

	const TCHAR* PassNames[]
	{
		TEXT("Material"),
		TEXT("MaskMaterial"),
		TEXT("CaptureRegionMaterial")
	};

	static_assert(UE_ARRAY_COUNT(PassNames) == static_cast<uint32>(EPass::MAX), "Pass names array doesn't match pass enum");

	TOverridePassSequence<EPass> PassSequence(Inputs.OverrideOutput);
	PassSequence.SetEnabled(EPass::Material, Inputs.Material != nullptr);
	PassSequence.SetEnabled(EPass::MaskMaterial, Inputs.MaskMaterial != nullptr && GIsHighResScreenshot);
	PassSequence.SetEnabled(EPass::CaptureRegionMaterial, Inputs.CaptureRegionMaterial != nullptr);
	PassSequence.Finalize();

	FScreenPassTexture Output = Inputs.SceneColor;

	if (PassSequence.IsEnabled(EPass::Material))
	{
		FPostProcessMaterialInputs PassInputs;
		PassSequence.AcceptOverrideIfLastPass(EPass::Material, PassInputs.OverrideOutput);
		PassInputs.SetInput(EPostProcessMaterialInput::SceneColor, Output);

		Output = AddPostProcessMaterialPass(GraphBuilder, View, PassInputs, Inputs.Material);
	}

	if (PassSequence.IsEnabled(EPass::MaskMaterial))
	{
		FPostProcessMaterialInputs PassInputs;
		PassSequence.AcceptOverrideIfLastPass(EPass::MaskMaterial, PassInputs.OverrideOutput);
		PassInputs.SetInput(EPostProcessMaterialInput::SceneColor, Output);

		Output = AddPostProcessMaterialPass(GraphBuilder, View, PassInputs, Inputs.MaskMaterial);

		AddDumpToColorArrayPass(GraphBuilder, Output, FScreenshotRequest::GetHighresScreenshotMaskColorArray());
	}

	if (PassSequence.IsEnabled(EPass::CaptureRegionMaterial))
	{
		FPostProcessMaterialInputs PassInputs;
		PassSequence.AcceptOverrideIfLastPass(EPass::CaptureRegionMaterial, PassInputs.OverrideOutput);
		PassInputs.SetInput(EPostProcessMaterialInput::SceneColor, Output);

		Output = AddPostProcessMaterialPass(GraphBuilder, View, PassInputs, Inputs.CaptureRegionMaterial);
	}

	return Output;
}

void AddHighResScreenshotMask(FPostprocessContext& Context)
{
	FRenderingCompositePass* Pass = Context.Graph.RegisterPass(
		new(FMemStack::Get()) TRCPassForRDG<1, 1>(
			[](FRenderingCompositePass* InPass, FRenderingCompositePassContext& InContext)
	{
		FRDGBuilder GraphBuilder(InContext.RHICmdList);

		FHighResolutionScreenshotMaskInputs PassInputs;
		PassInputs.SceneColor.Texture = InPass->CreateRDGTextureForRequiredInput(GraphBuilder, ePId_Input0, TEXT("SceneColor"));
		PassInputs.SceneColor.ViewRect = InContext.SceneColorViewRect;

		if (FRDGTextureRef OverrideOutputTexture = InPass->FindRDGTextureForOutput(GraphBuilder, ePId_Output0, TEXT("FrameBuffer")))
		{
			PassInputs.OverrideOutput.Texture = OverrideOutputTexture;
			PassInputs.OverrideOutput.ViewRect = InContext.GetSceneColorDestRect(InPass);
			PassInputs.OverrideOutput.LoadAction = InContext.View.IsFirstInFamily() ? ERenderTargetLoadAction::EClear : ERenderTargetLoadAction::ELoad;
		}

		FScreenPassTexture PassOutput = AddHighResolutionScreenshotMaskPass(GraphBuilder, InContext.View, PassInputs);

		InPass->ExtractRDGTextureForOutput(GraphBuilder, ePId_Output0, PassOutput.Texture);

		GraphBuilder.Execute();
	}));
	Pass->SetInput(ePId_Input0, Context.FinalOutput);
	Context.FinalOutput = Pass;
}