Files
UnrealEngineUWP/Engine/Source/Runtime/Renderer/Private/PostProcess/PostProcessCombineLUTs.cpp
2014-03-14 14:13:41 -04:00

436 lines
13 KiB
C++

// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.
/*=============================================================================
PostProcessCombineLUTs.cpp: Post processing tone mapping implementation.
=============================================================================*/
#include "RendererPrivate.h"
#include "ScenePrivate.h"
#include "SceneFilterRendering.h"
#include "PostProcessCombineLUTs.h"
#include "PostProcessing.h"
#include "ScreenRendering.h"
// false:use 256x16 texture / true:use volume texture (faster, requires geometry shader)
// USE_VOLUME_LUT: needs to be the same for C++ and HLSL
static bool UseVolumeTextureLUT()
{
return GRHIFeatureLevel >= ERHIFeatureLevel::SM4;
}
// including the neutral one at index 0
const uint32 GMaxLUTBlendCount = 5;
struct FColorTransform
{
FColorTransform()
{
Reset();
}
float MinValue;
float MidValue;
float MaxValue;
void Reset()
{
MinValue = 0.0f;
MidValue = 0.5f;
MaxValue = 1.0f;
}
};
/*-----------------------------------------------------------------------------
FColorRemapShaderParameters
-----------------------------------------------------------------------------*/
FColorRemapShaderParameters::FColorRemapShaderParameters(const FShaderParameterMap& ParameterMap)
{
MappingPolynomial.Bind(ParameterMap, TEXT("MappingPolynomial"));
}
void FColorRemapShaderParameters::Set(const FPixelShaderRHIParamRef ShaderRHI)
{
FColorTransform ColorTransform;
{
static const auto ICVarMin = IConsoleManager::Get().FindTConsoleVariableDataFloat(TEXT("r.Color.Min"));
static const auto ICVarMid = IConsoleManager::Get().FindTConsoleVariableDataFloat(TEXT("r.Color.Mid"));
static const auto ICVarMax = IConsoleManager::Get().FindTConsoleVariableDataFloat(TEXT("r.Color.Max"));
check(ICVarMin && ICVarMid && ICVarMax);
ColorTransform.MinValue = FMath::Clamp(ICVarMin->GetValueOnRenderThread(), -10.0f, 10.0f);
ColorTransform.MidValue = FMath::Clamp(ICVarMid->GetValueOnRenderThread(), -10.0f, 10.0f);
ColorTransform.MaxValue = FMath::Clamp(ICVarMax->GetValueOnRenderThread(), -10.0f, 10.0f);
}
{
// x is the input value, y the output value
// RGB = a, b, c where y = a * x*x + b * x + c
float c = ColorTransform.MinValue;
float b = 4 * ColorTransform.MidValue - 3 * ColorTransform.MinValue - ColorTransform.MaxValue;
float a = ColorTransform.MaxValue - ColorTransform.MinValue - b;
SetShaderValue(ShaderRHI, MappingPolynomial, FVector(a, b, c));
}
}
FArchive& operator<<(FArchive& Ar, FColorRemapShaderParameters& P)
{
Ar << P.MappingPolynomial;
return Ar;
}
/**
* A pixel shader for blending multiple LUT to one
*
* @param BlendCount >0
*/
template<uint32 BlendCount>
class FLUTBlenderPS : public FGlobalShader
{
DECLARE_SHADER_TYPE(FLUTBlenderPS,Global);
public:
static bool ShouldCache(EShaderPlatform Platform) { return IsFeatureLevelSupported(Platform, ERHIFeatureLevel::SM3); }
FLUTBlenderPS(const ShaderMetaType::CompiledShaderInitializerType& Initializer)
: FGlobalShader(Initializer)
, ColorRemapShaderParameters(Initializer.ParameterMap)
{
// Suppress static code analysis warnings about a potentially ill-defined loop. BlendCount > 0 is valid.
CA_SUPPRESS(6294)
// starts as 1 as 0 is the neutral one
for(uint32 i = 1; i < BlendCount; ++i)
{
FString Name = FString::Printf(TEXT("Texture%d"), i);
TextureParameter[i].Bind(Initializer.ParameterMap, *Name);
TextureParameterSampler[i].Bind(Initializer.ParameterMap, *(Name + TEXT("Sampler")));
}
WeightsParameter.Bind(Initializer.ParameterMap, TEXT("LUTWeights"));
ColorScale.Bind(Initializer.ParameterMap,TEXT("ColorScale"));
OverlayColor.Bind(Initializer.ParameterMap,TEXT("OverlayColor"));
}
FLUTBlenderPS() {}
void SetParameters(const FSceneView& View, FTexture* Texture[BlendCount], float Weights[BlendCount])
{
const FPixelShaderRHIParamRef ShaderRHI = GetPixelShader();
for(uint32 i = 0; i < BlendCount; ++i)
{
// we don't need to set the neutral one
if(i != 0)
{
SetTextureParameter(ShaderRHI, TextureParameter[i], TextureParameterSampler[i], Texture[i]);
}
SetShaderValue(ShaderRHI, WeightsParameter, Weights[i], i);
}
SetShaderValue(ShaderRHI, ColorScale, View.ColorScale);
SetShaderValue(ShaderRHI, OverlayColor, View.OverlayColor);
ColorRemapShaderParameters.Set(ShaderRHI);
}
static void ModifyCompilationEnvironment(EShaderPlatform Platform, FShaderCompilerEnvironment& OutEnvironment)
{
FGlobalShader::ModifyCompilationEnvironment(Platform, OutEnvironment);
OutEnvironment.SetDefine(TEXT("BLENDCOUNT"), BlendCount);
OutEnvironment.SetDefine(TEXT("USE_VOLUME_LUT"), UseVolumeTextureLUT());
}
virtual bool Serialize(FArchive& Ar)
{
bool bShaderHasOutdatedParameters = FGlobalShader::Serialize(Ar);
for(uint32 i = 0; i < BlendCount; ++i)
{
Ar << TextureParameter[i];
Ar << TextureParameterSampler[i];
}
Ar << WeightsParameter << ColorScale << OverlayColor;
Ar << ColorRemapShaderParameters;
return bShaderHasOutdatedParameters;
}
private: // ---------------------------------------------------
// [0] is not used as it's the neutral one we do in the shader
FShaderResourceParameter TextureParameter[GMaxLUTBlendCount];
FShaderResourceParameter TextureParameterSampler[GMaxLUTBlendCount];
FShaderParameter WeightsParameter;
FShaderParameter ColorScale;
FShaderParameter OverlayColor;
FColorRemapShaderParameters ColorRemapShaderParameters;
};
IMPLEMENT_SHADER_TYPE(template<>,FLUTBlenderPS<1>,TEXT("PostProcessCombineLUTs"),TEXT("MainPS"),SF_Pixel);
IMPLEMENT_SHADER_TYPE(template<>,FLUTBlenderPS<2>,TEXT("PostProcessCombineLUTs"),TEXT("MainPS"),SF_Pixel);
IMPLEMENT_SHADER_TYPE(template<>,FLUTBlenderPS<3>,TEXT("PostProcessCombineLUTs"),TEXT("MainPS"),SF_Pixel);
IMPLEMENT_SHADER_TYPE(template<>,FLUTBlenderPS<4>,TEXT("PostProcessCombineLUTs"),TEXT("MainPS"),SF_Pixel);
IMPLEMENT_SHADER_TYPE(template<>,FLUTBlenderPS<5>,TEXT("PostProcessCombineLUTs"),TEXT("MainPS"),SF_Pixel);
void SetLUTBlenderShader(FRenderingCompositePassContext& Context, uint32 BlendCount, FTexture* Texture[], float Weights[], const FVolumeBounds& VolumeBounds)
{
check(BlendCount > 0);
FShader* LocalPixelShader = 0;
FGlobalBoundShaderState* LocalBoundShaderState = 0;
const FSceneView& View = Context.View;
// A macro to handle setting the filter shader for a specific number of samples.
#define CASE_COUNT(BlendCount) \
case BlendCount: \
{ \
TShaderMapRef<FLUTBlenderPS<BlendCount> > PixelShader(GetGlobalShaderMap()); \
static FGlobalBoundShaderState BoundShaderState; \
LocalBoundShaderState = &BoundShaderState;\
LocalPixelShader = *PixelShader;\
}; \
break;
switch(BlendCount)
{
// starts at 1 as we always have at least the neutral one
CASE_COUNT(1);
CASE_COUNT(2);
CASE_COUNT(3);
CASE_COUNT(4);
CASE_COUNT(5);
// default:
// UE_LOG(LogRenderer, Fatal,TEXT("Invalid number of samples: %u"),BlendCount);
}
#undef CASE_COUNT
check(LocalBoundShaderState != NULL);
if(UseVolumeTextureLUT())
{
TShaderMapRef<FWriteToSliceVS> VertexShader(GetGlobalShaderMap());
TShaderMapRef<FWriteToSliceGS> GeometryShader(GetGlobalShaderMap());
SetGlobalBoundShaderState(*LocalBoundShaderState, GScreenVertexDeclaration.VertexDeclarationRHI, *VertexShader, LocalPixelShader, *GeometryShader);
VertexShader->SetParameters(VolumeBounds, VolumeBounds.MaxX - VolumeBounds.MinX);
GeometryShader->SetParameters(VolumeBounds);
}
else
{
TShaderMapRef<FPostProcessVS> VertexShader(GetGlobalShaderMap());
SetGlobalBoundShaderState(*LocalBoundShaderState, GFilterVertexDeclaration.VertexDeclarationRHI, *VertexShader, LocalPixelShader);
VertexShader->SetParameters(Context);
}
#define CASE_COUNT(BlendCount) \
case BlendCount: \
{ \
TShaderMapRef<FLUTBlenderPS<BlendCount> > PixelShader(GetGlobalShaderMap()); \
PixelShader->SetParameters(View, Texture, Weights); \
}; \
break;
switch(BlendCount)
{
// starts at 1 as we always have at least the neutral one
CASE_COUNT(1);
CASE_COUNT(2);
CASE_COUNT(3);
CASE_COUNT(4);
CASE_COUNT(5);
// default:
// UE_LOG(LogRenderer, Fatal,TEXT("Invalid number of samples: %u"),BlendCount);
}
#undef CASE_COUNT
}
uint32 FRCPassPostProcessCombineLUTs::FindIndex(const FFinalPostProcessSettings& Settings, UTexture* Tex) const
{
for(uint32 i = 0; i < (uint32)Settings.ContributingLUTs.Num(); ++i)
{
if(Settings.ContributingLUTs[i].LUTTexture == Tex)
{
return i;
}
}
return 0xffffffff;
}
uint32 FRCPassPostProcessCombineLUTs::GenerateFinalTable(const FFinalPostProcessSettings& Settings, FTexture* OutTextures[], float OutWeights[], uint32 MaxCount) const
{
// find the n strongest contributors, drop small contributors
// (inefficient implementation for many items but count should be small)
uint32 LocalCount = 1;
// add the neutral one (done in the shader) as it should be the first and always there
OutTextures[0] = 0;
{
uint32 NeutralIndex = FindIndex(Settings, 0);
OutWeights[0] = NeutralIndex == 0xffffffff ? 0.0f : Settings.ContributingLUTs[NeutralIndex].Weight;
}
float OutWeightsSum = OutWeights[0];
for(; LocalCount < MaxCount; ++LocalCount)
{
uint32 BestIndex = 0xffffffff;
// find the one with the strongest weight, add until full
for(uint32 i = 0; i < (uint32)Settings.ContributingLUTs.Num(); ++i)
{
bool AlreadyInArray = false;
{
UTexture* LUTTexture = Settings.ContributingLUTs[i].LUTTexture;
FTexture* Internal = LUTTexture ? LUTTexture->Resource : 0;
for(uint32 e = 0; e < LocalCount; ++e)
{
if(Internal == OutTextures[e])
{
AlreadyInArray = true;
break;
}
}
}
if(AlreadyInArray)
{
// we already have this one
continue;
}
if(BestIndex != 0xffffffff
&& Settings.ContributingLUTs[BestIndex].Weight > Settings.ContributingLUTs[i].Weight)
{
// we have a better ones, maybe add next time
continue;
}
BestIndex = i;
}
if(BestIndex == 0xffffffff)
{
// no more elements to process
break;
}
float BestWeight = Settings.ContributingLUTs[BestIndex].Weight;
if(BestWeight < 1.0f / 512.0f)
{
// drop small contributor
break;
}
UTexture* BestLUTTexture = Settings.ContributingLUTs[BestIndex].LUTTexture;
FTexture* BestInternal = BestLUTTexture ? BestLUTTexture->Resource : 0;
OutTextures[LocalCount] = BestInternal;
OutWeights[LocalCount] = BestWeight;
OutWeightsSum += BestWeight;
}
// normalize
if(OutWeightsSum > 0.001f)
{
float InvOutWeightsSum = 1.0f / OutWeightsSum;
for(uint32 i = 0; i < LocalCount; ++i)
{
OutWeights[i] *= InvOutWeightsSum;
}
}
else
{
// neutral only is fully utilized
OutWeights[0] = 1.0f;
LocalCount = 1;
}
return LocalCount;
}
void FRCPassPostProcessCombineLUTs::Process(FRenderingCompositePassContext& Context)
{
SCOPED_DRAW_EVENT(PostProcessCombineLUTs, DEC_SCENE_ITEMS);
FTexture* LocalTextures[GMaxLUTBlendCount];
float LocalWeights[GMaxLUTBlendCount];
const FSceneView& View = Context.View;
const FSceneViewFamily& ViewFamily = *(View.Family);
uint32 LocalCount = 1;
// set defaults for no LUT
LocalTextures[0] = 0;
LocalWeights[0] = 1.0f;
if(ViewFamily.EngineShowFlags.ColorGrading)
{
LocalCount = GenerateFinalTable(Context.View.FinalPostProcessSettings, LocalTextures, LocalWeights, GMaxLUTBlendCount);
}
// for a 3D texture, the viewport is 16x16 (per slice), for a 2D texture, it's unwrapped to 256x16
FIntPoint DestSize(UseVolumeTextureLUT() ? 16 : 256, 16);
const FSceneRenderTargetItem& DestRenderTarget = PassOutputs[0].RequestSurface(Context);
// Set the view family's render target/viewport.
RHISetRenderTarget(DestRenderTarget.TargetableTexture, FTextureRHIRef());
Context.SetViewportAndCallRHI(0, 0, 0.0f, DestSize.X, DestSize.Y, 1.0f );
// set the state
RHISetBlendState(TStaticBlendState<>::GetRHI());
RHISetRasterizerState(TStaticRasterizerState<>::GetRHI());
RHISetDepthStencilState(TStaticDepthStencilState<false,CF_Always>::GetRHI());
const FVolumeBounds VolumeBounds(16);
SetLUTBlenderShader(Context, LocalCount, LocalTextures, LocalWeights, VolumeBounds);
if(UseVolumeTextureLUT())
{
// use volume texture 16x16x16
RasterizeToVolumeTexture(VolumeBounds);
}
else
{
// use unwrapped 2d texture 256x16
DrawRectangle(
0, 0, // XY
16 * 16, 16, // SizeXY
0, 0, // UV
16 * 16, 16, // SizeUV
FIntPoint(16 * 16, 16), // TargetSize
FIntPoint(16 * 16, 16), // TextureSize
EDRF_UseTriangleOptimization);
}
RHICopyToResolveTarget(DestRenderTarget.TargetableTexture, DestRenderTarget.ShaderResourceTexture, false, FResolveParams());
}
FPooledRenderTargetDesc FRCPassPostProcessCombineLUTs::ComputeOutputDesc(EPassOutputId InPassOutputId) const
{
FPooledRenderTargetDesc Ret = FPooledRenderTargetDesc::Create2DDesc(FIntPoint(256, 16), PF_B8G8R8A8, TexCreate_None, TexCreate_RenderTargetable | TexCreate_ShaderResource, false);
if(UseVolumeTextureLUT())
{
Ret.Extent = FIntPoint(16, 16);
Ret.Depth = 16;
}
Ret.DebugName = TEXT("CombineLUTs");
return Ret;
}