C++ FTextureRHIRef函数代码示例

void FMediaTextureResource::UpdateDeferredResource(FRHICommandListImmediate& RHICmdList, bool bClearRenderTarget/*=true*/)
{
	FTimespan CurrentFrameTime = VideoBuffer->GetCurrentSampleTime();
	TSharedPtr<TArray<uint8>, ESPMode::ThreadSafe> CurrentFrame = VideoBuffer->GetCurrentSample();

	if (CurrentFrame.IsValid())
	{
		// draw the latest video frame
		if (CurrentFrameTime != LastFrameTime)
		{
			uint32 Stride = 0;
			FRHITexture2D* Texture2D = TextureRHI->GetTexture2D();
			uint8* TextureBuffer = (uint8*)RHILockTexture2D(Texture2D, 0, RLM_WriteOnly, Stride, false);

			FMemory::Memcpy(TextureBuffer, CurrentFrame->GetData(), CurrentFrame->Num());
			RHIUnlockTexture2D(Texture2D, 0, false);

			LastFrameTime = CurrentFrameTime;
			Cleared = false;
		}
	}
	else if (!Cleared || (LastClearColor != Owner->ClearColor))
	{
		// clear texture if video track selected
		FRHICommandListImmediate& CommandList = FRHICommandListExecutor::GetImmediateCommandList();

 		SetRenderTarget(CommandList, RenderTargetTextureRHI, FTextureRHIRef());
 		CommandList.SetViewport(0, 0, 0.0f, Owner->GetSurfaceWidth(), Owner->GetSurfaceHeight(), 1.0f);
 		CommandList.Clear(true, Owner->ClearColor, false, 0.f, false, 0, FIntRect());
		CommandList.CopyToResolveTarget(Texture2DRHI, TextureRHI, true, FResolveParams());

		LastClearColor = Owner->ClearColor;
		Cleared = true;
	}
}

void FSteamVRHMD::RenderTexture_RenderThread(FRHICommandListImmediate& RHICmdList, FTexture2DRHIParamRef BackBuffer, FTexture2DRHIParamRef SrcTexture) const
{
	check(IsInRenderingThread());

	if (WindowMirrorMode == 0)
	{
		return;
	}

	const uint32 ViewportWidth = BackBuffer->GetSizeX();
	const uint32 ViewportHeight = BackBuffer->GetSizeY();

	SetRenderTarget(RHICmdList, BackBuffer, FTextureRHIRef());
	RHICmdList.SetViewport(0, 0, 0, ViewportWidth, ViewportHeight, 1.0f);

	RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	const auto FeatureLevel = GMaxRHIFeatureLevel;
	auto ShaderMap = GetGlobalShaderMap(FeatureLevel);

	TShaderMapRef<FScreenVS> VertexShader(ShaderMap);
	TShaderMapRef<FScreenPS> PixelShader(ShaderMap);

	static FGlobalBoundShaderState BoundShaderState;
	SetGlobalBoundShaderState(RHICmdList, FeatureLevel, BoundShaderState, RendererModule->GetFilterVertexDeclaration().VertexDeclarationRHI, *VertexShader, *PixelShader);

	PixelShader->SetParameters(RHICmdList, TStaticSamplerState<SF_Bilinear>::GetRHI(), SrcTexture);

	if (WindowMirrorMode == 1)
	{
		// need to clear when rendering only one eye since the borders won't be touched by the DrawRect below
		RHICmdList.Clear(true, FLinearColor::Black, false, 0, false, 0, FIntRect());

		RendererModule->DrawRectangle(
			RHICmdList,
			ViewportWidth / 4, 0,
			ViewportWidth / 2, ViewportHeight,
			0.1f, 0.2f,
			0.3f, 0.6f,
			FIntPoint(ViewportWidth, ViewportHeight),
			FIntPoint(1, 1),
			*VertexShader,
			EDRF_Default);
	}
	else if (WindowMirrorMode == 2)
	{
		RendererModule->DrawRectangle(
			RHICmdList,
			0, 0,
			ViewportWidth, ViewportHeight,
			0.0f, 0.0f,
			1.0f, 1.0f,
			FIntPoint(ViewportWidth, ViewportHeight),
			FIntPoint(1, 1),
			*VertexShader,
			EDRF_Default);
	}
}

void FRCPassPostProcessAA::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessAA);

	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);

	FIntRect SrcRect = View.ViewRect;
	FIntRect DestRect = View.ViewRect;
	FIntPoint SrcSize = InputDesc->Extent;
	FIntPoint DestSize = PassOutputs[0].RenderTargetDesc.Extent;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());
	Context.SetViewportAndCallRHI(0, 0, 0.0f, DestSize.X, DestSize.Y, 1.0f );

	// set the state
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	switch(Quality)
	{
		case 1:  SetShaderTemplAA<1>(Context); break;
		case 2:  SetShaderTemplAA<2>(Context); break;
		case 3:  SetShaderTemplAA<3>(Context); break;
		case 4:  SetShaderTemplAA<4>(Context); break;
		case 5:  SetShaderTemplAA<5>(Context); break;
		default: SetShaderTemplAA<6>(Context); break;
	}
	
	// Draw a quad mapping scene color to the view's render target
	TShaderMapRef<FFXAAVS> VertexShader(Context.GetShaderMap());

	DrawRectangle(
		Context.RHICmdList,
		DestRect.Min.X, DestRect.Min.Y,
		DestRect.Width(), DestRect.Height(),
		SrcRect.Min.X, SrcRect.Min.Y,
		SrcRect.Width(), SrcRect.Height(),
		DestSize,
		SrcSize,
		*VertexShader,
		EDRF_Default);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessLensBlur::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PassPostProcessLensBlur);

	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);
	
	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;

	FIntPoint TexSize = InputDesc->Extent;

	// usually 1, 2, 4 or 8
	uint32 ScaleToFullRes = GSceneRenderTargets.GetBufferSizeXY().X / TexSize.X;

	FIntRect ViewRect = FIntRect::DivideAndRoundUp(View.ViewRect, ScaleToFullRes);
	FIntPoint ViewSize = ViewRect.Size();

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef(), ESimpleRenderTargetMode::EClearColorToBlack);

	Context.SetViewportAndCallRHI(ViewRect);

	// set the state (additive blending)
	Context.RHICmdList.SetBlendState(TStaticBlendState<CW_RGB, BO_Add, BF_One, BF_One>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	TShaderMapRef<FPostProcessLensBlurVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FPostProcessLensBlurPS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState BoundShaderState;
	
	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), BoundShaderState, GEmptyVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	uint32 TileSize = 1;

	FIntPoint TileCount = ViewSize / TileSize;

	float PixelKernelSize = PercentKernelSize / 100.0f * ViewSize.X;

	VertexShader->SetParameters(Context, TileCount, TileSize, PixelKernelSize, Threshold);
	PixelShader->SetParameters(Context, PixelKernelSize);

	Context.RHICmdList.SetStreamSource(0, NULL, 0, 0);

	// needs to be the same on shader side (faster on NVIDIA and AMD)
	int32 QuadsPerInstance = 4;

	Context.RHICmdList.DrawPrimitive(PT_TriangleList, 0, 2, FMath::DivideAndRoundUp(TileCount.X * TileCount.Y, QuadsPerInstance));

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessMorpheus::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessMorpheus);
	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
	FIntRect SrcRect = View.ViewRect;
	FIntRect DestRect = View.UnscaledViewRect;
	FIntPoint SrcSize = InputDesc->Extent;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());

	Context.SetViewportAndCallRHI(DestRect);

	// set the state
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	TShaderMapRef<FPostProcessMorpheusVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FPostProcessMorpheusPS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState BoundShaderState;
	

	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), BoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	FMatrix QuadTexTransform;
	FMatrix QuadPosTransform = FMatrix::Identity;

	PixelShader->SetPS(Context, SrcRect, SrcSize, View.StereoPass, QuadTexTransform);

	// Draw a quad mapping scene color to the view's render target
	DrawTransformedRectangle(
		Context.RHICmdList,
		0, 0,
		DestRect.Width(), DestRect.Height(),
		QuadPosTransform,
		SrcRect.Min.X, SrcRect.Min.Y,
		SrcRect.Width(), SrcRect.Height(),
		QuadTexTransform,
		DestRect.Size(),
		SrcSize
		);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessVisualizeBloomOverlay::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, VisualizeBloomOverlay);

	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	check(InputDesc && "Input is not hooked up correctly");

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);

	FIntPoint SrcSize = InputDesc->Extent;
	FIntPoint DestSize = PassOutputs[0].RenderTargetDesc.Extent;

	// e.g. 4 means the input texture is 4x smaller than the buffer size
	uint32 ScaleFactor = GSceneRenderTargets.GetBufferSizeXY().X / SrcSize.X;

	FIntRect SrcRect = View.ViewRect / ScaleFactor;
	FIntRect DestRect = SrcRect;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());

	// is optimized away if possible (RT size=view size, )
	Context.RHICmdList.Clear(true, FLinearColor(0, 0, 0, 0), false, 1.0f, false, 0, DestRect);

	Context.SetViewportAndCallRHI(0, 0, 0.0f, DestRect.Width(), DestRect.Height(), 1.0f );

	// set the state
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	TShaderMapRef<FPostProcessVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FPostProcessVisualizeBloomOverlayPS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState BoundShaderState;

	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), BoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	PixelShader->SetParameters(Context);
	VertexShader->SetParameters(Context);

	// Draw a quad mapping scene color to the view's render target
	DrawRectangle(
		Context.RHICmdList,
		DestRect.Min.X, DestRect.Min.Y,
		DestRect.Width(), DestRect.Height(),
		SrcRect.Min.X, SrcRect.Min.Y,
		SrcRect.Width(), SrcRect.Height(),
		DestRect.Size(),
		SrcSize,
		*VertexShader,
		EDRF_UseTriangleOptimization);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessVisualizeLPV::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, VisualizeLPV);

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
//	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);
	const TRefCountPtr<IPooledRenderTarget> RenderTarget = GetInput(ePId_Input0)->GetOutput()->PooledRenderTarget;
	const FSceneRenderTargetItem& DestRenderTarget = RenderTarget->GetRenderTargetItem();

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());

	{
		FRenderTargetTemp TempRenderTarget(View, (const FTexture2DRHIRef&)DestRenderTarget.TargetableTexture);
		FCanvas Canvas(&TempRenderTarget, NULL, ViewFamily.CurrentRealTime, ViewFamily.CurrentWorldTime, ViewFamily.DeltaWorldTime, View.GetFeatureLevel());

		float X = 30;
		float Y = 28;
		const float YStep = 14;
		const float ColumnWidth = 250;

		Canvas.DrawShadowedString( X, Y += YStep, TEXT("VisualizeLightPropagationVolume"), GetStatsFont(), FLinearColor(0.2f, 0.2f, 1));

		Y += YStep;

		const FLightPropagationVolumeSettings& Dest = View.FinalPostProcessSettings.BlendableManager.GetSingleFinalDataConst<FLightPropagationVolumeSettings>();

#define ENTRY(name)\
		Canvas.DrawShadowedString( X, Y += YStep, TEXT(#name) TEXT(":"), GetStatsFont(), FLinearColor(1, 1, 1));\
		Canvas.DrawShadowedString( X + ColumnWidth, Y, *FString::Printf(TEXT("%g"), Dest.name), GetStatsFont(), FLinearColor(1, 1, 1));

		ENTRY(LPVIntensity)
		ENTRY(LPVVplInjectionBias)
		ENTRY(LPVSize)
		ENTRY(LPVSecondaryOcclusionIntensity)
		ENTRY(LPVSecondaryBounceIntensity)
		ENTRY(LPVGeometryVolumeBias)
		ENTRY(LPVEmissiveInjectionIntensity)
		ENTRY(LPVDirectionalOcclusionIntensity)
		ENTRY(LPVDirectionalOcclusionRadius)
		ENTRY(LPVDiffuseOcclusionExponent)
		ENTRY(LPVSpecularOcclusionExponent)
		ENTRY(LPVDiffuseOcclusionIntensity)
		ENTRY(LPVSpecularOcclusionIntensity)
#undef ENTRY

		Canvas.Flush_RenderThread(Context.RHICmdList);
	}

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
	
	// to satify following passws
	FRenderingCompositeOutput* Output = GetOutput(ePId_Output0);
	
	Output->PooledRenderTarget = RenderTarget;
}

void FRCPassPostProcessHistogramReduce::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessHistogramReduce);
	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
	FIntPoint SrcSize = InputDesc->Extent;
	FIntPoint DestSize = PassOutputs[0].RenderTargetDesc.Extent;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());

	// set the state
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	TShaderMapRef<FPostProcessVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FPostProcessHistogramReducePS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState BoundShaderState;
	

	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), BoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	// we currently assume the input is half res, one full res pixel less to avoid getting bilinear filtered input
	FIntPoint GatherExtent = (View.ViewRect.Size() - FIntPoint(1, 1)) / 2;

	uint32 LoopSizeValue = ComputeLoopSize(GatherExtent);

	PixelShader->SetPS(Context, LoopSizeValue);

	DrawPostProcessPass(
		Context.RHICmdList,
		0, 0,
		DestSize.X, DestSize.Y,
		0, 0,
		SrcSize.X, 0,
		DestSize,
		SrcSize,
		*VertexShader,
		View.StereoPass,
		Context.HasHmdMesh(),
		EDRF_UseTriangleOptimization);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessVisualizeMotionBlur::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(VisualizeMotionBlur, DEC_SCENE_ITEMS);

	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;

	FIntPoint TexSize = InputDesc->Extent;

	// we assume the input and output is full resolution

	FIntPoint SrcSize = InputDesc->Extent;
	FIntPoint DestSize = PassOutputs[0].RenderTargetDesc.Extent;

	// e.g. 4 means the input texture is 4x smaller than the buffer size
	uint32 ScaleFactor = GSceneRenderTargets.GetBufferSizeXY().X / SrcSize.X;

	FIntRect SrcRect = FIntRect::DivideAndRoundUp(View.ViewRect, ScaleFactor);
	FIntRect DestRect = SrcRect;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	RHISetRenderTarget(DestRenderTarget.TargetableTexture, FTextureRHIRef());
	
	// is optimized away if possible (RT size=view size, )
	RHIClear(true, FLinearColor::Black, false, 1.0f, false, 0, SrcRect);

	Context.SetViewportAndCallRHI(SrcRect);

	// set the state
	RHISetBlendState(TStaticBlendState<>::GetRHI());
	RHISetRasterizerState(TStaticRasterizerState<>::GetRHI());
	RHISetDepthStencilState(TStaticDepthStencilState<false,CF_Always>::GetRHI());

	// Quality 0: visualize
	SetMotionBlurShaderTempl<0>(Context);

	// Draw a quad mapping scene color to the view's render target
	DrawRectangle(
		0, 0,
		SrcRect.Width(), SrcRect.Height(),
		SrcRect.Min.X, SrcRect.Min.Y, 
		SrcRect.Width(), SrcRect.Height(),
		SrcRect.Size(),
		SrcSize,
		EDRF_UseTriangleOptimization);

	RHICopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessHistogram::Process(FRenderingCompositePassContext& Context)
{
    SCOPED_DRAW_EVENT(PostProcessHistogram, DEC_SCENE_ITEMS);
    const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

    if(!InputDesc)
    {
        // input is not hooked up correctly
        return;
    }

    const FSceneView& View = Context.View;
    const FSceneViewFamily& ViewFamily = *(View.Family);

    FIntPoint SrcSize = InputDesc->Extent;
    FIntRect DestRect = View.ViewRect;

    const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

    TShaderMapRef<FPostProcessHistogramCS> ComputeShader(GetGlobalShaderMap());

    RHISetComputeShader(ComputeShader->GetComputeShader());
    RHISetRenderTarget(FTextureRHIRef(), FTextureRHIRef());


    // set destination
    check(DestRenderTarget.UAV);
    RHISetUAVParameter(ComputeShader->GetComputeShader(), ComputeShader->HistogramRWTexture.GetBaseIndex(), DestRenderTarget.UAV);

    // we currently assume the input is half res, one full res pixel less to avoid getting bilinear filtered input
    FIntPoint GatherExtent = (DestRect.Size() - FIntPoint(1, 1)) / 2;

    FIntPoint ThreadGroupCountValue = ComputeThreadGroupCount(GatherExtent);


    ComputeShader->SetCS(Context, ThreadGroupCountValue, (DestRect.Min + FIntPoint(1, 1)) / 2, GatherExtent);

    DispatchComputeShader(*ComputeShader, ThreadGroupCountValue.X, ThreadGroupCountValue.Y, 1);

    // un-set destination
    RHISetUAVParameter(ComputeShader->GetComputeShader(), ComputeShader->HistogramRWTexture.GetBaseIndex(), NULL);

    RHICopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessHistogram::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessHistogram);
	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
	FIntPoint SrcSize = InputDesc->Extent;
	FIntRect DestRect = View.ViewRect;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	TShaderMapRef<FPostProcessHistogramCS> ComputeShader(Context.GetShaderMap());

	SetRenderTarget(Context.RHICmdList, FTextureRHIRef(), FTextureRHIRef());
    Context.RHICmdList.SetComputeShader(ComputeShader->GetComputeShader());
    

	// set destination
	check(DestRenderTarget.UAV);
	Context.RHICmdList.TransitionResource(EResourceTransitionAccess::ERWBarrier, EResourceTransitionPipeline::EGfxToCompute, DestRenderTarget.UAV);
	Context.RHICmdList.SetUAVParameter(ComputeShader->GetComputeShader(), ComputeShader->HistogramRWTexture.GetBaseIndex(), DestRenderTarget.UAV);

	FIntPoint GatherExtent = ComputeGatherExtent(View);
	FIntPoint ThreadGroupCountValue = ComputeThreadGroupCount(GatherExtent);

	ComputeShader->SetCS(Context.RHICmdList, Context, ThreadGroupCountValue, (DestRect.Min + FIntPoint(1, 1)) / 2, GatherExtent);
	
	DispatchComputeShader(Context.RHICmdList, *ComputeShader, ThreadGroupCountValue.X, ThreadGroupCountValue.Y, 1);

	// un-set destination
	Context.RHICmdList.SetUAVParameter(ComputeShader->GetComputeShader(), ComputeShader->HistogramRWTexture.GetBaseIndex(), NULL);

	Context.RHICmdList.TransitionResource(EResourceTransitionAccess::EReadable, EResourceTransitionPipeline::EComputeToGfx, DestRenderTarget.UAV);
	ensureMsgf(DestRenderTarget.TargetableTexture == DestRenderTarget.ShaderResourceTexture, TEXT("%s should be resolved to a separate SRV"), *DestRenderTarget.TargetableTexture->GetName().ToString());	
}

void FRCPassPostProcessVelocityFlatten::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessVelocityFlatten);
	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
	const FSceneRenderTargetItem& DestRenderTarget0 = PassOutputs[0].RequestSurface(Context);
	const FSceneRenderTargetItem& DestRenderTarget1 = PassOutputs[1].RequestSurface(Context);
	//const FSceneRenderTargetItem& DestRenderTarget2 = PassOutputs[2].RequestSurface(Context);

	TShaderMapRef< FPostProcessVelocityFlattenCS > ComputeShader( Context.GetShaderMap() );

	Context.RHICmdList.SetComputeShader(ComputeShader->GetComputeShader());
	SetRenderTarget(Context.RHICmdList, FTextureRHIRef(), FTextureRHIRef());

	// set destination
	Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutVelocityFlat.GetBaseIndex(), DestRenderTarget0.UAV );
	//Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutPackedVelocityDepth.GetBaseIndex(), DestRenderTarget1.UAV );
	Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutMaxTileVelocity.GetBaseIndex(), DestRenderTarget1.UAV );

	ComputeShader->SetCS(Context.RHICmdList, Context, View );
	
	FIntPoint ThreadGroupCountValue = ComputeThreadGroupCount( View.ViewRect.Size() );
	DispatchComputeShader(Context.RHICmdList, *ComputeShader, ThreadGroupCountValue.X, ThreadGroupCountValue.Y, 1);

	// un-set destination
	Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutVelocityFlat.GetBaseIndex(), NULL );
	//Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutPackedVelocityDepth.GetBaseIndex(), NULL );
	Context.RHICmdList.SetUAVParameter( ComputeShader->GetComputeShader(), ComputeShader->OutMaxTileVelocity.GetBaseIndex(), NULL );

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget0.TargetableTexture, DestRenderTarget0.ShaderResourceTexture, false, FResolveParams());
	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget1.TargetableTexture, DestRenderTarget1.ShaderResourceTexture, false, FResolveParams());
	//Context.RHICmdList.CopyToResolveTarget(DestRenderTarget1.TargetableTexture, DestRenderTarget2.ShaderResourceTexture, false, FResolveParams());
}

void FRCPassPostProcessVisualizeComplexity::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, PostProcessVisualizeComplexity);
	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);
	
	FIntRect SrcRect = View.ViewRect;
	FIntRect DestRect = View.UnscaledViewRect;
	FIntPoint SrcSize = InputDesc->Extent;

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());
	Context.SetViewportAndCallRHI(DestRect);

	// turn off culling and blending
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<FM_Solid, CM_None>::GetRHI());
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());

	// turn off depth reads/writes
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	//reuse this generic vertex shader
	TShaderMapRef<FShaderComplexityApplyVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FShaderComplexityApplyPS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState ShaderComplexityBoundShaderState;
	
	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), ShaderComplexityBoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	PixelShader->SetParameters(Context, Colors);
	
	DrawRectangle(
		Context.RHICmdList,
		0, 0,
		DestRect.Width(), DestRect.Height(),
		SrcRect.Min.X, SrcRect.Min.Y,
		SrcRect.Width(), SrcRect.Height(),
		DestRect.Size(),
		SrcSize,
		*VertexShader,
		EDRF_UseTriangleOptimization);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}

void FOculusRiftHMD::CopyTexture_RenderThread(FRHICommandListImmediate& RHICmdList, FTexture2DRHIParamRef DstTexture, FTexture2DRHIParamRef SrcTexture, 
	FIntRect DstRect, FIntRect SrcRect) const
{
	check(IsInRenderingThread());

	if (DstRect.IsEmpty())
	{
		DstRect = FIntRect(0, 0, DstTexture->GetSizeX(), DstTexture->GetSizeY());
	}
	const uint32 ViewportWidth = DstRect.Width();
	const uint32 ViewportHeight = DstRect.Height();
	const FIntPoint TargetSize(ViewportWidth, ViewportHeight);

	const float SrcTextureWidth = SrcTexture->GetSizeX();
	const float SrcTextureHeight = SrcTexture->GetSizeY();
	float U = 0.f, V = 0.f, USize = 1.f, VSize = 1.f;
	if (!SrcRect.IsEmpty())
	{
		U = SrcRect.Min.X / SrcTextureWidth;
		V = SrcRect.Min.Y / SrcTextureHeight;
		USize = SrcRect.Width() / SrcTextureWidth;
		VSize = SrcRect.Height() / SrcTextureHeight;
	}

	SetRenderTarget(RHICmdList, DstTexture, FTextureRHIRef());
	RHICmdList.SetViewport(DstRect.Min.X, DstRect.Min.Y, 0, DstRect.Max.X, DstRect.Max.Y, 1.0f);

	RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());

	const auto FeatureLevel = GMaxRHIFeatureLevel;
	auto ShaderMap = GetGlobalShaderMap(FeatureLevel);

	TShaderMapRef<FScreenVS> VertexShader(ShaderMap);
	TShaderMapRef<FScreenPS> PixelShader(ShaderMap);

	static FGlobalBoundShaderState BoundShaderState;
	SetGlobalBoundShaderState(RHICmdList, FeatureLevel, BoundShaderState, RendererModule->GetFilterVertexDeclaration().VertexDeclarationRHI, *VertexShader, *PixelShader);

	PixelShader->SetParameters(RHICmdList, TStaticSamplerState<SF_Bilinear>::GetRHI(), SrcTexture);

	RendererModule->DrawRectangle(
		RHICmdList,
		0, 0,
		ViewportWidth, ViewportHeight,
		U, V,
		USize, VSize,
		TargetSize,
		FIntPoint(1, 1),
		*VertexShader,
		EDRF_Default);
}

void FRCPassPostProcessSceneColorFringe::Process(FRenderingCompositePassContext& Context)
{
	SCOPED_DRAW_EVENT(Context.RHICmdList, SceneColorFringe);

	const FPooledRenderTargetDesc* InputDesc = GetInputDesc(ePId_Input0);

	if(!InputDesc)
	{
		// input is not hooked up correctly
		return;
	}

	const FSceneView& View = Context.View;
	const FSceneViewFamily& ViewFamily = *(View.Family);

	const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);

	// Set the view family's render target/viewport.
	SetRenderTarget(Context.RHICmdList, DestRenderTarget.TargetableTexture, FTextureRHIRef());
	Context.SetViewportAndCallRHI(View.ViewRect);

	// set the state
	Context.RHICmdList.SetBlendState(TStaticBlendState<>::GetRHI());
	Context.RHICmdList.SetRasterizerState(TStaticRasterizerState<>::GetRHI());
	Context.RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always>::GetRHI());
	
	TShaderMapRef<FPostProcessSceneColorFringeVS> VertexShader(Context.GetShaderMap());
	TShaderMapRef<FPostProcessSceneColorFringePS> PixelShader(Context.GetShaderMap());

	static FGlobalBoundShaderState BoundShaderState;
	

	SetGlobalBoundShaderState(Context.RHICmdList, Context.GetFeatureLevel(), BoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, *PixelShader);

	PixelShader->SetParameters(Context);
	VertexShader->SetParameters(Context);
	
	// Draw a quad mapping scene color to the view's render target
	DrawRectangle(
		Context.RHICmdList,
		0, 0,
		View.ViewRect.Width(), View.ViewRect.Height(),
		View.ViewRect.Min.X, View.ViewRect.Min.Y, 
		View.ViewRect.Width(), View.ViewRect.Height(),
		View.ViewRect.Size(),
		FSceneRenderTargets::Get(Context.RHICmdList).GetBufferSizeXY(),
		*VertexShader,
		EDRF_UseTriangleOptimization);

	Context.RHICmdList.CopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}