UnrealEngineUWP/Engine/Source/Runtime/Renderer/Private/EditorCompositeParams.cpp

// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.
#include "EditorCompositeParams.h"
#include "RHIStaticStates.h"
#include "MaterialShared.h"
#include "PostProcess/SceneRenderTargets.h"
#include "ShaderParameterUtils.h"

FEditorCompositingParameters::FEditorCompositingParameters()
{
}

void FEditorCompositingParameters::Bind(const FShaderParameterMap& ParameterMap)
{
	EditorCompositeDepthTestParameter.Bind(ParameterMap, TEXT("bEnableEditorPrimitiveDepthTest"));
	MSAASampleCount.Bind(ParameterMap, TEXT("MSAASampleCount"));
	FilteredSceneDepthTexture.Bind(ParameterMap, TEXT("FilteredSceneDepthTexture"));
	FilteredSceneDepthTextureSampler.Bind(ParameterMap, TEXT("FilteredSceneDepthTextureSampler"));
}

void FEditorCompositingParameters::SetParameters(
	FRHICommandList& RHICmdList,
	const FMaterial& MaterialResource,
	const FSceneView* View,
	bool bEnableEditorPrimitveDepthTest,
	const FPixelShaderRHIParamRef ShaderRHI)
{
#if WITH_EDITOR
		if (GMaxRHIFeatureLevel >= ERHIFeatureLevel::SM4 && MaterialResource.IsUsedWithEditorCompositing())
		{
			// Compute parameters for converting from screen space to pixel
			FIntRect DestRect = View->ViewRect;
			FIntPoint ViewportOffset = DestRect.Min;
			FIntPoint ViewportExtent = DestRect.Size();

			FVector4 ScreenPosToPixelValue(
				ViewportExtent.X * 0.5f,
				-ViewportExtent.Y * 0.5f,
				ViewportExtent.X * 0.5f - 0.5f + ViewportOffset.X,
				ViewportExtent.Y * 0.5f - 0.5f + ViewportOffset.Y);

			FSceneRenderTargets& SceneContext = FSceneRenderTargets::Get(RHICmdList);
			if (FilteredSceneDepthTexture.IsBound())
			{
				const FTexture2DRHIRef* DepthTexture = SceneContext.GetActualDepthTexture();
				check(DepthTexture != NULL);
				SetTextureParameter(
					RHICmdList,
					ShaderRHI,
					FilteredSceneDepthTexture,
					FilteredSceneDepthTextureSampler,
					TStaticSamplerState<SF_Bilinear, AM_Clamp, AM_Clamp, AM_Clamp>::GetRHI(),
					*DepthTexture
					);
			}

			SetShaderValue(RHICmdList, ShaderRHI, EditorCompositeDepthTestParameter, bEnableEditorPrimitveDepthTest);
			SetShaderValue(RHICmdList, ShaderRHI, MSAASampleCount, SceneContext.EditorPrimitivesColor ? SceneContext.EditorPrimitivesColor->GetDesc().NumSamples : 0);
		}
		else
#endif
		{
			if (FilteredSceneDepthTexture.IsBound())
			{
				FSceneRenderTargets& SceneContext = FSceneRenderTargets::Get(RHICmdList);
				const FTexture2DRHIRef* DepthTexture = SceneContext.GetActualDepthTexture();
				check(DepthTexture != NULL);
				SetTextureParameter(
									RHICmdList,
									ShaderRHI,
									FilteredSceneDepthTexture,
									FilteredSceneDepthTextureSampler,
									TStaticSamplerState<SF_Bilinear, AM_Clamp, AM_Clamp, AM_Clamp>::GetRHI(),
									*DepthTexture
									);
			}
			SetShaderValue(RHICmdList, ShaderRHI, EditorCompositeDepthTestParameter, false);
			SetShaderValue(RHICmdList, ShaderRHI, MSAASampleCount, 0);
		}
}