UnrealEngineUWP/Engine/Source/Runtime/Landscape/Private/LandscapeEditInterface.cpp

// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.

/*=============================================================================
LandscapeEditInterface.cpp: Landscape editing interface
=============================================================================*/

#include "CoreMinimal.h"
#include "GenericPlatform/GenericPlatformStackWalk.h"
#include "Templates/Greater.h"
#include "Containers/ArrayView.h"
#include "RenderingThread.h"
#include "LandscapeProxy.h"
#include "Landscape.h"
#include "LandscapeInfo.h"
#include "LandscapeComponent.h"
#include "LandscapeLayerInfoObject.h"

#if WITH_EDITOR

#include "LandscapeDataAccess.h"
#include "LandscapeEdit.h"
#include "LandscapeRender.h"
#include "ComponentReregisterContext.h"
#include "Containers/Algo/Transform.h"

// Channel remapping
extern const size_t ChannelOffsets[4] = {STRUCT_OFFSET(FColor,R), STRUCT_OFFSET(FColor,G), STRUCT_OFFSET(FColor,B), STRUCT_OFFSET(FColor,A)};

//
// FLandscapeEditDataInterface
//
FLandscapeEditDataInterface::FLandscapeEditDataInterface(ULandscapeInfo* InLandscapeInfo)
{
	if (InLandscapeInfo)
	{
		LandscapeInfo			= InLandscapeInfo;
		ComponentSizeQuads		= InLandscapeInfo->ComponentSizeQuads;
		SubsectionSizeQuads		= InLandscapeInfo->SubsectionSizeQuads;
		ComponentNumSubsections = InLandscapeInfo->ComponentNumSubsections;
		DrawScale				= InLandscapeInfo->DrawScale;
	}
}

FLandscapeTextureDataInterface::~FLandscapeTextureDataInterface()
{
	Flush();
}

void FLandscapeTextureDataInterface::Flush()
{
	bool bNeedToWaitForUpdate = false;

	// Update all textures
	for( TMap<UTexture2D*, FLandscapeTextureDataInfo*>::TIterator It(TextureDataMap); It;  ++It )
	{
		if( It.Value()->UpdateTextureData() )
		{
			bNeedToWaitForUpdate = true;
		}
	}

	if( bNeedToWaitForUpdate )
	{
		FlushRenderingCommands();
	}

	// delete all the FLandscapeTextureDataInfo allocations
	for( TMap<UTexture2D*, FLandscapeTextureDataInfo*>::TIterator It(TextureDataMap); It;  ++It )
	{
		delete It.Value();	// FLandscapeTextureDataInfo destructors will unlock any texture data
	}

	TextureDataMap.Empty();
}

#include "LevelUtils.h"

void ALandscape::CalcComponentIndicesOverlap(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, const int32 ComponentSizeQuads, 
											 int32& ComponentIndexX1, int32& ComponentIndexY1, int32& ComponentIndexX2, int32& ComponentIndexY2)
{
	// Find component range for this block of data
	ComponentIndexX1 = (X1-1 >= 0) ? (X1-1) / ComponentSizeQuads : (X1) / ComponentSizeQuads - 1;	// -1 because we need to pick up vertices shared between components
	ComponentIndexY1 = (Y1-1 >= 0) ? (Y1-1) / ComponentSizeQuads : (Y1) / ComponentSizeQuads - 1;
	ComponentIndexX2 = (X2 >= 0) ? X2 / ComponentSizeQuads : (X2+1) / ComponentSizeQuads - 1;
	ComponentIndexY2 = (Y2 >= 0) ? Y2 / ComponentSizeQuads : (Y2+1) / ComponentSizeQuads - 1;
}

void ALandscape::CalcComponentIndicesNoOverlap(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, const int32 ComponentSizeQuads, 
									  int32& ComponentIndexX1, int32& ComponentIndexY1, int32& ComponentIndexX2, int32& ComponentIndexY2)
{
	// Find component range for this block of data
	ComponentIndexX1 = (X1 >= 0) ? X1 / ComponentSizeQuads : (X1+1) / ComponentSizeQuads - 1;	// -1 because we need to pick up vertices shared between components
	ComponentIndexY1 = (Y1 >= 0) ? Y1 / ComponentSizeQuads : (Y1+1) / ComponentSizeQuads - 1;
	ComponentIndexX2 = (X2-1 >= 0) ? (X2-1) / ComponentSizeQuads : (X2) / ComponentSizeQuads - 1;
	ComponentIndexY2 = (Y2-1 >= 0) ? (Y2-1) / ComponentSizeQuads : (Y2) / ComponentSizeQuads - 1;
	// Shrink indices for shared values
	if ( ComponentIndexX2 < ComponentIndexX1)
	{
		ComponentIndexX2 = ComponentIndexX1;
	}
	if ( ComponentIndexY2 < ComponentIndexY1)
	{
		ComponentIndexY2 = ComponentIndexY1;
	}
}

namespace
{
	// Ugly helper function, all arrays should be only size 4
	template<typename T, typename F>
	FORCEINLINE void CalcInterpValue(const int32* Dist, const bool* Exist, const T* Value, F& ValueX, F& ValueY)
	{
		if (Exist[0] && Exist[1])
		{
			ValueX = (F)(Dist[1] * Value[0] + Dist[0] * Value[1]) / (Dist[0] + Dist[1]);
		}
		else
		{
			if (Exist[0])
			{
				ValueX = Value[0];
			}
			else if (Exist[1])
			{
				ValueX = Value[1];
			}
		}

		if (Exist[2] && Exist[3])
		{
			ValueY = (F)(Dist[3] * Value[2] + Dist[2] * Value[3]) / (Dist[2] + Dist[3]);
		}
		else
		{
			if (Exist[2])
			{
				ValueY = Value[2];
			}
			else if (Exist[3])
			{
				ValueY = Value[3];
			}
		}
	}

	template<typename T>
	FORCEINLINE T CalcValueFromValueXY( const int32* Dist, const T& ValueX, const T& ValueY, const uint8& CornerSet, const T* CornerValues )
	{
		T FinalValue;
		int32 DistX = FMath::Min(Dist[0], Dist[1]);
		int32 DistY = FMath::Min(Dist[2], Dist[3]);
		if (DistX+DistY > 0)
		{
			FinalValue = ((ValueX * DistY) + (ValueY * DistX)) / (float)(DistX + DistY);
		}
		else
		{
			if ((CornerSet & 1) && Dist[0] == 0 && Dist[2] == 0)
			{
				FinalValue = CornerValues[0];
			}
			else if ((CornerSet & 1 << 1) && Dist[1] == 0 && Dist[2] == 0)
			{
				FinalValue = CornerValues[1];
			}
			else if ((CornerSet & 1 << 2) && Dist[0] == 0 && Dist[3] == 0)
			{
				FinalValue = CornerValues[2];
			}
			else if ((CornerSet & 1 << 3) && Dist[1] == 0 && Dist[3] == 0)
			{
				FinalValue = CornerValues[3];
			}
			else
			{
				FinalValue = ValueX;
			}
		}
		return FinalValue;
	}

};

bool FLandscapeEditDataInterface::GetComponentsInRegion(int32 X1, int32 Y1, int32 X2, int32 Y2, TSet<ULandscapeComponent*>* OutComponents /*= nullptr*/)
{
	if (ComponentSizeQuads <= 0 || !LandscapeInfo)
	{
		return false;
	}
	// Find component range for this block of data
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	bool bNotLocked = true;
	for (int32 ComponentIndexY = ComponentIndexY1; ComponentIndexY <= ComponentIndexY2; ComponentIndexY++)
	{
		for (int32 ComponentIndexX = ComponentIndexX1; ComponentIndexX <= ComponentIndexX2; ComponentIndexX++)
		{
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, ComponentIndexY));
			if (Component)
			{
				bNotLocked = bNotLocked && (!FLevelUtils::IsLevelLocked(Component->GetLandscapeProxy()->GetLevel())) && FLevelUtils::IsLevelVisible(Component->GetLandscapeProxy()->GetLevel());
				if (OutComponents)
				{
					OutComponents->Add(Component);
				}
			}
		}
	}
	return bNotLocked;
}

void FLandscapeEditDataInterface::SetHeightData(int32 X1, int32 Y1, int32 X2, int32 Y2, const uint16* Data, int32 Stride, bool CalcNormals, const uint16* NormalData /*= NULL*/, bool CreateComponents /*= false*/)
{
	const int32 NumVertsX = 1 + X2 - X1;
	const int32 NumVertsY = 1 + Y2 - Y1;

	if (Stride == 0)
	{
		Stride = NumVertsX;
	}

	check(ComponentSizeQuads > 0);
	// Find component range for this block of data
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	FVector* VertexNormals = nullptr;
	if (CalcNormals)
	{
		// Calculate the normals for each of the two triangles per quad.
		// Note that the normals at the edges are not correct because they include normals
		// from triangles outside the current area. They are not updated
		VertexNormals = new FVector[NumVertsX*NumVertsY];
		FMemory::Memzero(VertexNormals, NumVertsX*NumVertsY*sizeof(FVector));

		// Need to consider XYOffset for XY displacemented map
		FVector2D* XYOffsets = new FVector2D[NumVertsX*NumVertsY];
		FMemory::Memzero(XYOffsets, NumVertsX*NumVertsY*sizeof(FVector2D));
		GetXYOffsetDataFast(X1, Y1, X2, Y2, XYOffsets, 0);

		for (int32 Y = 0; Y < NumVertsY - 1; Y++)
		{
			for (int32 X = 0; X < NumVertsX - 1; X++)
			{
				FVector Vert00 = FVector(XYOffsets[(X+0) + NumVertsX*(Y+0)].X,      XYOffsets[(X+0) + NumVertsX*(Y+0)].Y,      ((float)Data[(X+0) + Stride*(Y+0)] - 32768.0f) * LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert01 = FVector(XYOffsets[(X+0) + NumVertsX*(Y+0)].X,      XYOffsets[(X+0) + NumVertsX*(Y+0)].Y+1.0f, ((float)Data[(X+0) + Stride*(Y+1)] - 32768.0f) * LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert10 = FVector(XYOffsets[(X+0) + NumVertsX*(Y+0)].X+1.0f, XYOffsets[(X+0) + NumVertsX*(Y+0)].Y,      ((float)Data[(X+1) + Stride*(Y+0)] - 32768.0f) * LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert11 = FVector(XYOffsets[(X+0) + NumVertsX*(Y+0)].X+1.0f, XYOffsets[(X+0) + NumVertsX*(Y+0)].Y+1.0f, ((float)Data[(X+1) + Stride*(Y+1)] - 32768.0f) * LANDSCAPE_ZSCALE) * DrawScale;

				FVector FaceNormal1 = ((Vert00-Vert10) ^ (Vert10-Vert11)).GetSafeNormal();
				FVector FaceNormal2 = ((Vert11-Vert01) ^ (Vert01-Vert00)).GetSafeNormal(); 

				// contribute to the vertex normals.
				VertexNormals[(X+1 + NumVertsX*(Y+0))] += FaceNormal1;
				VertexNormals[(X+0 + NumVertsX*(Y+1))] += FaceNormal2;
				VertexNormals[(X+0 + NumVertsX*(Y+0))] += FaceNormal1 + FaceNormal2;
				VertexNormals[(X+1 + NumVertsX*(Y+1))] += FaceNormal1 + FaceNormal2;
			}
		}

		delete[] XYOffsets;
	}

	for (int32 ComponentIndexY = ComponentIndexY1; ComponentIndexY <= ComponentIndexY2; ComponentIndexY++)
	{
		for (int32 ComponentIndexX = ComponentIndexX1; ComponentIndexX <= ComponentIndexX2; ComponentIndexX++)
		{
			FIntPoint ComponentKey(ComponentIndexX, ComponentIndexY);
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(ComponentKey);

			// if nullptr, it was painted away
			if (Component == nullptr)
			{
				if (CreateComponents)
				{
					// not yet implemented
					continue;
				}
				else
				{
					continue;
				}
			}

			Component->Modify();

			FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(Component->HeightmapTexture);
			FColor* HeightmapTextureData = (FColor*)TexDataInfo->GetMipData(0);

			FColor* XYOffsetMipData = nullptr;
			if (Component->XYOffsetmapTexture)
			{
				FLandscapeTextureDataInfo* XYTexDataInfo = GetTextureDataInfo(Component->XYOffsetmapTexture);
				XYOffsetMipData = (FColor*)XYTexDataInfo->GetMipData(Component->CollisionMipLevel); 
			}

			// Find the texture data corresponding to this vertex
			int32 SizeU = Component->HeightmapTexture->Source.GetSizeX();
			int32 SizeV = Component->HeightmapTexture->Source.GetSizeY();
			int32 HeightmapOffsetX = Component->HeightmapScaleBias.Z * (float)SizeU;
			int32 HeightmapOffsetY = Component->HeightmapScaleBias.W * (float)SizeV;

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			// To adjust bounding box
			uint16 MinHeight = MAX_uint16;
			uint16 MaxHeight = 0;

			for (int32 SubIndexY = SubIndexY1; SubIndexY <= SubIndexY2; SubIndexY++)
			{
				for (int32 SubIndexX = SubIndexX1; SubIndexX <= SubIndexX2; SubIndexX++)
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for (int32 SubY = SubY1; SubY <= SubY2; SubY++)
					{
						for (int32 SubX = SubX1; SubX <= SubX2; SubX++)
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;
							checkSlow(LandscapeX >= X1 && LandscapeX <= X2);
							checkSlow(LandscapeY >= Y1 && LandscapeY <= Y2);

							// Find the input data corresponding to this vertex
							int32 DataIndex = (LandscapeX-X1) + Stride * (LandscapeY-Y1);
							const uint16& Height = Data[DataIndex];

							// for bounding box
							if (Height < MinHeight)
							{
								MinHeight = Height;
							}
							if (Height > MaxHeight)
							{
								MaxHeight = Height;
							}

							int32 TexX = HeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
							int32 TexY = HeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
							FColor& TexData = HeightmapTextureData[TexX + TexY * SizeU];

							// Update the texture
							TexData.R = Height >> 8;
							TexData.G = Height & 255;

							// Update normals if we're not on an edge vertex
							if (VertexNormals && LandscapeX > X1 && LandscapeX < X2 && LandscapeY > Y1 && LandscapeY < Y2)
							{
								const int32 NormalDataIndex = (LandscapeX-X1) + NumVertsX * (LandscapeY-Y1);
								FVector Normal = VertexNormals[NormalDataIndex].GetSafeNormal();
								TexData.B = FMath::RoundToInt(127.5f * (Normal.X + 1.0f));
								TexData.A = FMath::RoundToInt(127.5f * (Normal.Y + 1.0f));
							}
							else if (NormalData)
							{
								// Need data validation?
								const uint16& Normal = NormalData[DataIndex];
								TexData.B = Normal >> 8;
								TexData.A = Normal & 255;
							}
						}
					}

					// Record the areas of the texture we need to re-upload
					int32 TexX1 = HeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX1;
					int32 TexY1 = HeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY1;
					int32 TexX2 = HeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX2;
					int32 TexY2 = HeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY2;
					TexDataInfo->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);
				}
			}

			// See if we need to adjust the bounds. Note we never shrink the bounding box at this point
			float MinLocalZ = LandscapeDataAccess::GetLocalHeight(MinHeight);
			float MaxLocalZ = LandscapeDataAccess::GetLocalHeight(MaxHeight);

			bool bUpdateBoxSphereBounds = false;
			if (MinLocalZ < Component->CachedLocalBox.Min.Z)
			{
				Component->CachedLocalBox.Min.Z = MinLocalZ;
				bUpdateBoxSphereBounds = true;
			}
			if (MaxLocalZ > Component->CachedLocalBox.Max.Z)
			{
				Component->CachedLocalBox.Max.Z = MaxLocalZ;
				bUpdateBoxSphereBounds = true;
			}

			if (bUpdateBoxSphereBounds)
			{
				Component->UpdateComponentToWorld();
			}

			// Update mipmaps

			// Work out how many mips should be calculated directly from one component's data.
			// The remaining mips are calculated on a per texture basis.
			// eg if subsection is 7x7 quads, we need one 3 mips total: (8x8, 4x4, 2x2 verts)
			int32 BaseNumMips = FMath::CeilLogTwo(SubsectionSizeQuads+1);
			TArray<FColor*> MipData;
			MipData.AddUninitialized(BaseNumMips);
			MipData[0] = HeightmapTextureData;
			for (int32 MipIdx = 1; MipIdx < BaseNumMips; MipIdx++)
			{
				MipData[MipIdx] = (FColor*)TexDataInfo->GetMipData(MipIdx);
			}
			Component->GenerateHeightmapMips(MipData, ComponentX1, ComponentY1, ComponentX2, ComponentY2, TexDataInfo);

			// Update collision
			Component->UpdateCollisionHeightData(
				MipData[Component->CollisionMipLevel],
				Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? MipData[Component->SimpleCollisionMipLevel] : nullptr,
				ComponentX1, ComponentY1, ComponentX2, ComponentY2, bUpdateBoxSphereBounds,
				XYOffsetMipData);

			// Update GUID for Platform Data
			FPlatformMisc::CreateGuid(Component->StateId);
		}
	}

	if (VertexNormals)
	{
		delete[] VertexNormals;
	}
}

//
// RecalculateNormals - Regenerate normals for the entire landscape. Called after modifying DrawScale3D.
//
void FLandscapeEditDataInterface::RecalculateNormals()
{
	if (!LandscapeInfo) return;
	// Recalculate normals for each component in turn
	for( auto It = LandscapeInfo->XYtoComponentMap.CreateIterator(); It; ++It )
	{
		ULandscapeComponent* Component = It.Value();

		// one extra row of vertex either side of the component
		int32 X1 = Component->GetSectionBase().X-1;
		int32 Y1 = Component->GetSectionBase().Y-1;
		int32 X2 = Component->GetSectionBase().X+ComponentSizeQuads+1;
		int32 Y2 = Component->GetSectionBase().Y+ComponentSizeQuads+1;
		int32 Stride = ComponentSizeQuads+3; 

		uint16* HeightData = new uint16[FMath::Square(Stride)];
		FVector* VertexNormals = new FVector[FMath::Square(Stride)];
		FMemory::Memzero(VertexNormals, FMath::Square(Stride)*sizeof(FVector));
		FVector2D* XYOffsets = new FVector2D[FMath::Square(Stride)];
		FMemory::Memzero(XYOffsets, FMath::Square(Stride)*sizeof(FVector2D));

		// Get XY offset
		GetXYOffsetDataFast(X1,Y1,X2,Y2,XYOffsets,0);
		// Get the vertex positions for entire quad
		GetHeightData(X1,Y1,X2,Y2,HeightData,0);

		// Contribute face normals for all triangles contributing to this components' normals
		for( int32 Y=0;Y<Stride-1;Y++ )
		{
			for( int32 X=0;X<Stride-1;X++ )
			{
				FVector Vert00 = FVector(XYOffsets[(X+0) + Stride*(Y+0)].X,		XYOffsets[(X+0) + Stride*(Y+0)].Y, ((float)HeightData[(X+0) + Stride*(Y+0)] - 32768.0f)*LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert01 = FVector(XYOffsets[(X+0) + Stride*(Y+0)].X,		XYOffsets[(X+0) + Stride*(Y+0)].Y+1.0f, ((float)HeightData[(X+0) + Stride*(Y+1)] - 32768.0f)*LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert10 = FVector(XYOffsets[(X+0) + Stride*(Y+0)].X+1.0f,	XYOffsets[(X+0) + Stride*(Y+0)].Y, ((float)HeightData[(X+1) + Stride*(Y+0)] - 32768.0f)*LANDSCAPE_ZSCALE) * DrawScale;
				FVector Vert11 = FVector(XYOffsets[(X+0) + Stride*(Y+0)].X+1.0f,	XYOffsets[(X+0) + Stride*(Y+0)].Y+1.0f,((float)HeightData[(X+1) + Stride*(Y+1)] - 32768.0f)*LANDSCAPE_ZSCALE) * DrawScale;

				FVector FaceNormal1 = ((Vert00-Vert10) ^ (Vert10-Vert11)).GetSafeNormal();
				FVector FaceNormal2 = ((Vert11-Vert01) ^ (Vert01-Vert00)).GetSafeNormal(); 

				// contribute to the vertex normals.
				VertexNormals[(X+1 + Stride*(Y+0))] += FaceNormal1;
				VertexNormals[(X+0 + Stride*(Y+1))] += FaceNormal2;
				VertexNormals[(X+0 + Stride*(Y+0))] += FaceNormal1 + FaceNormal2;
				VertexNormals[(X+1 + Stride*(Y+1))] += FaceNormal1 + FaceNormal2;
			}
		}

		// Find the texture data corresponding to this vertex
		int32 SizeU = Component->HeightmapTexture->Source.GetSizeX();
		int32 SizeV = Component->HeightmapTexture->Source.GetSizeY();
		int32 HeightmapOffsetX = Component->HeightmapScaleBias.Z * (float)SizeU;
		int32 HeightmapOffsetY = Component->HeightmapScaleBias.W * (float)SizeV;

		FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(Component->HeightmapTexture);
		FColor* HeightmapTextureData = (FColor*)TexDataInfo->GetMipData(0);

		// Apply vertex normals to the component
		for( int32 SubIndexY=0;SubIndexY<Component->NumSubsections;SubIndexY++ )
		{
			for( int32 SubIndexX=0;SubIndexX<Component->NumSubsections;SubIndexX++ )
			{
				for( int32 SubY=0;SubY<=SubsectionSizeQuads;SubY++ )
				{
					for( int32 SubX=0;SubX<=SubsectionSizeQuads;SubX++ )
					{
						int32 X = (SubsectionSizeQuads+1) * SubIndexX + SubX;
						int32 Y = (SubsectionSizeQuads+1) * SubIndexY + SubY;
						int32 DataIndex = (X+1) + (Y+1) * Stride;

						int32 TexX = HeightmapOffsetX + X;
						int32 TexY = HeightmapOffsetY + Y;
						FColor& TexData = HeightmapTextureData[ TexX + TexY * SizeU ];

						// Update the texture
						FVector Normal = VertexNormals[DataIndex].GetSafeNormal();
						TexData.B = FMath::RoundToInt( 127.5f * (Normal.X + 1.0f) );
						TexData.A = FMath::RoundToInt( 127.5f * (Normal.Y + 1.0f) );
					}
				}
			}
		}

		delete[] XYOffsets;
		delete[] HeightData;
		delete[] VertexNormals;

		// Record the areas of the texture we need to re-upload
		int32 TexX1 = HeightmapOffsetX;
		int32 TexY1 = HeightmapOffsetY;
		int32 TexX2 = HeightmapOffsetX + (SubsectionSizeQuads+1) * Component->NumSubsections - 1;
		int32 TexY2 = HeightmapOffsetY + (SubsectionSizeQuads+1) * Component->NumSubsections - 1;
		TexDataInfo->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);

		// Work out how many mips should be calculated directly from one component's data.
		// The remaining mips are calculated on a per texture basis.
		// eg if subsection is 7x7 quads, we need one 3 mips total: (8x8, 4x4, 2x2 verts)
		int32 BaseNumMips = FMath::CeilLogTwo(SubsectionSizeQuads+1);
		TArray<FColor*> MipData;
		MipData.AddUninitialized(BaseNumMips);
		MipData[0] = HeightmapTextureData;
		for( int32 MipIdx=1;MipIdx<BaseNumMips;MipIdx++ )
		{
			MipData[MipIdx] = (FColor*)TexDataInfo->GetMipData(MipIdx);
		}
		Component->GenerateHeightmapMips( MipData, 0, 0, ComponentSizeQuads, ComponentSizeQuads, TexDataInfo );
	}
}

template<typename TStoreData>
void FLandscapeEditDataInterface::GetHeightDataTemplFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TStoreData& StoreData, TStoreData* NormalData /*= NULL*/)
{
	if (!LandscapeInfo) return;
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{		
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			FColor* HeightmapTextureData = NULL;
			if( Component )
			{
				TexDataInfo = GetTextureDataInfo(Component->HeightmapTexture);
				HeightmapTextureData = (FColor*)TexDataInfo->GetMipData(0);
			}
			else
			{
				continue;
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							// Find the texture data corresponding to this vertex
							int32 SizeU = Component->HeightmapTexture->Source.GetSizeX();
							int32 SizeV = Component->HeightmapTexture->Source.GetSizeY();
							int32 HeightmapOffsetX = Component->HeightmapScaleBias.Z * (float)SizeU;
							int32 HeightmapOffsetY = Component->HeightmapScaleBias.W * (float)SizeV;

							int32 TexX = HeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
							int32 TexY = HeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
							FColor& TexData = HeightmapTextureData[ TexX + TexY * SizeU ];

							uint16 Height = (((uint16)TexData.R) << 8) | TexData.G;
							StoreData.Store(LandscapeX, LandscapeY, Height);
							if (NormalData)
							{
								uint16 Normals = (((uint16)TexData.B) << 8) | TexData.A;
								NormalData->Store(LandscapeX, LandscapeY, Normals);
							}
						}
					}
				}
			}
		}
	}
}

template<typename TData, typename TStoreData, typename FType>
void FLandscapeEditDataInterface::CalcMissingValues(const int32& X1, const int32& X2, const int32& Y1, const int32& Y2, 
								   const int32& ComponentIndexX1, const int32& ComponentIndexX2, const int32& ComponentIndexY1, const int32& ComponentIndexY2, 
								   const int32& ComponentSizeX, const int32& ComponentSizeY, TData* CornerValues, 
								   TArray<bool>& NoBorderY1, TArray<bool>& NoBorderY2, TArray<bool>& ComponentDataExist, TStoreData& StoreData)
{
	bool NoBorderX1 = false, NoBorderX2 = false;
	// Init data...
	FMemory::Memzero(NoBorderY1.GetData(), ComponentSizeX*sizeof(bool));
	FMemory::Memzero(NoBorderY2.GetData(), ComponentSizeX*sizeof(bool));
	int32 BorderX1 = INT_MAX, BorderX2 = INT_MIN;
	TArray<int32> BorderY1, BorderY2;
	BorderY1.Empty(ComponentSizeX);
	BorderY2.Empty(ComponentSizeX);
	for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
	{
		new (BorderY1) int32(INT_MAX);
		new (BorderY2) int32(INT_MIN);
	}

	// fill up missing values...
	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		NoBorderX1 = false;
		NoBorderX2 = false;
		BorderX1 = INT_MAX;
		BorderX2 = INT_MIN;
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{
			int32 ComponentIndexXY = ComponentSizeX*(ComponentIndexY-ComponentIndexY1) + ComponentIndexX-ComponentIndexX1;
			if (!ComponentDataExist[ComponentIndexXY])
			{
				int32 ComponentIndexXX = ComponentIndexX - ComponentIndexX1;
				int32 ComponentIndexYY = ComponentIndexY - ComponentIndexY1;

				uint8 CornerSet = 0;
				bool ExistLeft = ComponentIndexXX > 0 && ComponentDataExist[ ComponentIndexXX-1 + ComponentIndexYY * ComponentSizeX ];
				bool ExistUp = ComponentIndexYY > 0 && ComponentDataExist[ ComponentIndexXX + (ComponentIndexYY-1) * ComponentSizeX ];

				// Search for neighbor component for interpolation
				bool bShouldSearchX = (BorderX2 <= ComponentIndexX);
				bool bShouldSearchY = (BorderY2[ComponentIndexXX] <= ComponentIndexY);
				// Search for left-closest component
				if ( bShouldSearchX || (!NoBorderX1 && BorderX1 == INT_MAX) )
				{
					NoBorderX1 = true;
					BorderX1 = INT_MAX;
					for (int32 X = ComponentIndexX-1; X >= ComponentIndexX1; X--)
					{
						if (ComponentDataExist[ComponentSizeX*(ComponentIndexY-ComponentIndexY1) + X-ComponentIndexX1])
						{
							NoBorderX1 = false;
							BorderX1 = X;
							break;
						}
					}
				}
				// Search for right-closest component
				if ( bShouldSearchX || (!NoBorderX2 && BorderX2 == INT_MIN) )
				{
					NoBorderX2 = true;
					BorderX2 = INT_MIN;
					for (int32 X = ComponentIndexX+1; X <= ComponentIndexX2; X++)
					{
						if (ComponentDataExist[ComponentSizeX*(ComponentIndexY-ComponentIndexY1) + X-ComponentIndexX1])
						{
							NoBorderX2 = false;
							BorderX2 = X;
							break;
						}
					}
				}
				// Search for up-closest component
				if ( bShouldSearchY || (!NoBorderY1[ComponentIndexXX] && BorderY1[ComponentIndexXX] == INT_MAX))
				{
					NoBorderY1[ComponentIndexXX] = true;
					BorderY1[ComponentIndexXX] = INT_MAX;
					for (int32 Y = ComponentIndexY-1; Y >= ComponentIndexY1; Y--)
					{
						if (ComponentDataExist[ComponentSizeX*(Y-ComponentIndexY1) + ComponentIndexX-ComponentIndexX1])
						{
							NoBorderY1[ComponentIndexXX] = false;
							BorderY1[ComponentIndexXX] = Y;
							break;
						}
					}
				}
				// Search for bottom-closest component
				if ( bShouldSearchY || (!NoBorderY2[ComponentIndexXX] && BorderY2[ComponentIndexXX] == INT_MIN))
				{
					NoBorderY2[ComponentIndexXX] = true;
					BorderY2[ComponentIndexXX] = INT_MIN;
					for (int32 Y = ComponentIndexY+1; Y <= ComponentIndexY2; Y++)
					{
						if (ComponentDataExist[ComponentSizeX*(Y-ComponentIndexY1) + ComponentIndexX-ComponentIndexX1])
						{
							NoBorderY2[ComponentIndexXX] = false;
							BorderY2[ComponentIndexXX] = Y;
							break;
						}
					}
				}

				if (((ComponentIndexX == ComponentIndexX1) || (ComponentIndexY == ComponentIndexY1)) ? false : ComponentDataExist[ComponentSizeX*(ComponentIndexY-1-ComponentIndexY1) + ComponentIndexX-1-ComponentIndexX1])
				{
					CornerSet |= 1;
					CornerValues[0] = TData(StoreData.Load(ComponentIndexX*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads));
				}
				if (((ComponentIndexX == ComponentIndexX2) || (ComponentIndexY == ComponentIndexY1)) ? false : ComponentDataExist[ComponentSizeX*(ComponentIndexY-1-ComponentIndexY1) + ComponentIndexX+1-ComponentIndexX1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = TData(StoreData.Load((ComponentIndexX + 1)*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads));
				}
				if (((ComponentIndexX == ComponentIndexX1) || (ComponentIndexY == ComponentIndexY2)) ? false : ComponentDataExist[ComponentSizeX*(ComponentIndexY+1-ComponentIndexY1) + ComponentIndexX-1-ComponentIndexX1])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = TData(StoreData.Load(ComponentIndexX*ComponentSizeQuads, (ComponentIndexY + 1)*ComponentSizeQuads));
				}
				if (((ComponentIndexX == ComponentIndexX2) || (ComponentIndexY == ComponentIndexY2)) ? false : ComponentDataExist[ComponentSizeX*(ComponentIndexY+1-ComponentIndexY1) + ComponentIndexX+1-ComponentIndexX1])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = TData(StoreData.Load((ComponentIndexX + 1)*ComponentSizeQuads, (ComponentIndexY + 1)*ComponentSizeQuads));
				}

				FillCornerValues(CornerSet, CornerValues);

				// Find coordinates of box that lies inside component
				int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
				int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
				int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
				int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

				// Find subsection range for this box
				int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
				int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
				int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
				int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

				for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
				{
					for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
					{
						// Find coordinates of box that lies inside subsection
						int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
						int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
						int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
						int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

						// Update texture data for the box that lies inside subsection
						for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
						{
							for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
							{
								int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
								int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

								// Find the texture data corresponding to this vertex
								TData Value[4];
								FMemory::Memzero(Value, sizeof(TData)* 4);
								int32 Dist[4] = {INT_MAX, INT_MAX, INT_MAX, INT_MAX};
								FType ValueX, ValueY;
								FMemory::Memzero(&ValueX, sizeof(FType));
								FMemory::Memzero(&ValueY, sizeof(FType));
								bool Exist[4] = {false, false, false, false};

								if (ExistLeft)
								{
									Value[0] = TData(StoreData.Load(ComponentIndexX*ComponentSizeQuads, LandscapeY));
									Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
									Exist[0] = true;
								}
								else if ( BorderX1 != INT_MAX )
								{
									int32 BorderIdxX = (BorderX1+1)*ComponentSizeQuads;
									Value[0] = TData(StoreData.Load(BorderIdxX, LandscapeY));
									Dist[0] = LandscapeX - (BorderIdxX-1);
									Exist[0] = true;
								}
								else 
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 2))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
										Value[0] = (FType)(Dist2 * CornerValues[0] + Dist1 * CornerValues[2]) / (Dist1 + Dist2);
										Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										Exist[0] = true;
									}
								}

								if ( BorderX2 != INT_MIN )
								{
									int32 BorderIdxX = BorderX2*ComponentSizeQuads;
									Value[1] = TData(StoreData.Load(BorderIdxX, LandscapeY));
									Dist[1] = (BorderIdxX+1) - LandscapeX;
									Exist[1] = true;
								}
								else 
								{
									if ((CornerSet & 1 << 1) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
										Value[1] = (FType)(Dist2 * CornerValues[1] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[1] = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Exist[1] = true;
									}
								}

								if (ExistUp)
								{
									Value[2] = TData(StoreData.Load(LandscapeX, ComponentIndexY*ComponentSizeQuads));
									Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
									Exist[2] = true;
								}
								else if ( BorderY1[ComponentIndexXX] != INT_MAX )
								{
									int32 BorderIdxY = (BorderY1[ComponentIndexXX]+1)*ComponentSizeQuads;
									Value[2] = TData(StoreData.Load(LandscapeX, BorderIdxY));
									Dist[2] = LandscapeY - BorderIdxY;
									Exist[2] = true;
								}
								else 
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 1))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Value[2] = (FType)(Dist2 * CornerValues[0] + Dist1 * CornerValues[1]) / (Dist1 + Dist2);
										Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										Exist[2] = true;
									}
								}

								if ( BorderY2[ComponentIndexXX] != INT_MIN )
								{
									int32 BorderIdxY = BorderY2[ComponentIndexXX]*ComponentSizeQuads;
									Value[3] = TData(StoreData.Load(LandscapeX, BorderIdxY));
									Dist[3] = BorderIdxY - LandscapeY;
									Exist[3] = true;
								}
								else 
								{
									if ((CornerSet & 1 << 2) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Value[3] = (FType)(Dist2 * CornerValues[2] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[3] = (ComponentIndexY+1)*ComponentSizeQuads - LandscapeY;
										Exist[3] = true;
									}
								}

								CalcInterpValue<TData, FType>(Dist, Exist, Value, ValueX, ValueY);

								TData FinalValue; // Default Value
								FMemory::Memzero(&FinalValue, sizeof(TData));
								if ( (Exist[0] || Exist[1]) && (Exist[2] || Exist[3]) )
								{
									FinalValue = CalcValueFromValueXY<TData>(Dist, ValueX, ValueY, CornerSet, CornerValues);
								}
								else if ( (Exist[0] || Exist[1]) )
								{
									FinalValue = ValueX;
								}
								else if ( (Exist[2] || Exist[3]) )
								{
									FinalValue = ValueY;
								}

								StoreData.Store(LandscapeX, LandscapeY, FinalValue);
							}
						}
					}
				}
			}
		}
	}
}

uint16 FLandscapeEditDataInterface::GetHeightMapData(const ULandscapeComponent* Component, int32 TexU, int32 TexV, FColor* TextureData /*= NULL*/)
{
	check(Component);
	if (!TextureData)
	{
		FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(Component->HeightmapTexture);
		TextureData = (FColor*)TexDataInfo->GetMipData(0);	
	}

	int32 SizeU = Component->HeightmapTexture->Source.GetSizeX();
	int32 SizeV = Component->HeightmapTexture->Source.GetSizeY();
	int32 HeightmapOffsetX = Component->HeightmapScaleBias.Z * (float)SizeU;
	int32 HeightmapOffsetY = Component->HeightmapScaleBias.W * (float)SizeV;

	int32 TexX = HeightmapOffsetX + TexU;
	int32 TexY = HeightmapOffsetY + TexV;
	FColor& TexData = TextureData[ TexX + TexY * SizeU ];

	return ((((uint16)TexData.R) << 8) | TexData.G);
}

template<typename TStoreData>
void FLandscapeEditDataInterface::GetHeightDataTempl(int32& ValidX1, int32& ValidY1, int32& ValidX2, int32& ValidY2, TStoreData& StoreData)
{
	// Copy variables
	int32 X1 = ValidX1, X2 = ValidX2, Y1 = ValidY1, Y2 = ValidY2;
	ValidX1 = INT_MAX; ValidX2 = INT_MIN; ValidY1 = INT_MAX; ValidY2 = INT_MIN;

	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	int32 ComponentSizeX = ComponentIndexX2-ComponentIndexX1+1;
	int32 ComponentSizeY = ComponentIndexY2-ComponentIndexY1+1;

	// Neighbor Components
	ULandscapeComponent* BorderComponent[4] = {0, 0, 0, 0};
	ULandscapeComponent* CornerComponent[4] = {0, 0, 0, 0};
	bool NoBorderX1 = false, NoBorderX2 = false;
	TArray<bool> NoBorderY1, NoBorderY2, ComponentDataExist;
	TArray<ULandscapeComponent*> BorderComponentY1, BorderComponentY2;
	ComponentDataExist.Empty(ComponentSizeX*ComponentSizeY);
	ComponentDataExist.AddZeroed(ComponentSizeX*ComponentSizeY);
	bool bHasMissingValue = false;

	FLandscapeTextureDataInfo* NeighborTexDataInfo[4] = {0, 0, 0, 0};
	FColor* NeighborHeightmapTextureData[4] = {0, 0, 0, 0};
	uint16 CornerValues[4] = {0, 0, 0, 0};

	int32 EdgeCoord = (SubsectionSizeQuads+1) * ComponentNumSubsections - 1; //ComponentSizeQuads;

	// initial loop....
	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		NoBorderX1 = false;
		NoBorderX2 = false;
		BorderComponent[0] = BorderComponent[1] = NULL;
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{
			BorderComponent[2] = BorderComponent[3] = NULL;
			int32 ComponentIndexXY = ComponentSizeX*(ComponentIndexY-ComponentIndexY1) + ComponentIndexX-ComponentIndexX1;
			int32 ComponentIndexXX = ComponentIndexX - ComponentIndexX1;
			int32 ComponentIndexYY = ComponentIndexY - ComponentIndexY1;
			ComponentDataExist[ComponentIndexXY] = false;
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			FColor* HeightmapTextureData = NULL;
			uint8 CornerSet = 0;
			bool ExistLeft = ComponentIndexXX > 0 && ComponentDataExist[ ComponentIndexXX-1 + ComponentIndexYY * ComponentSizeX ];
			bool ExistUp = ComponentIndexYY > 0 && ComponentDataExist[ ComponentIndexXX + (ComponentIndexYY-1) * ComponentSizeX ];

			if( Component )
			{
				TexDataInfo = GetTextureDataInfo(Component->HeightmapTexture);
				HeightmapTextureData = (FColor*)TexDataInfo->GetMipData(0);
				ComponentDataExist[ComponentIndexXY] = true;
				// Update valid region
				ValidX1 = FMath::Min<int32>(Component->GetSectionBase().X, ValidX1);
				ValidX2 = FMath::Max<int32>(Component->GetSectionBase().X+ComponentSizeQuads, ValidX2);
				ValidY1 = FMath::Min<int32>(Component->GetSectionBase().Y, ValidY1);
				ValidY2 = FMath::Max<int32>(Component->GetSectionBase().Y+ComponentSizeQuads, ValidY2);
			}
			else
			{
				if (!bHasMissingValue)
				{
					NoBorderY1.Empty(ComponentSizeX);
					NoBorderY2.Empty(ComponentSizeX);
					NoBorderY1.AddZeroed(ComponentSizeX);
					NoBorderY2.AddZeroed(ComponentSizeX);
					BorderComponentY1.Empty(ComponentSizeX);
					BorderComponentY2.Empty(ComponentSizeX);
					BorderComponentY1.AddZeroed(ComponentSizeX);
					BorderComponentY2.AddZeroed(ComponentSizeX);
					bHasMissingValue = true;
				}

				// Search for neighbor component for interpolation
				bool bShouldSearchX = (BorderComponent[1] && BorderComponent[1]->GetSectionBase().X / ComponentSizeQuads <= ComponentIndexX);
				bool bShouldSearchY = (BorderComponentY2[ComponentIndexXX] && BorderComponentY2[ComponentIndexXX]->GetSectionBase().Y / ComponentSizeQuads <= ComponentIndexY);
				// Search for left-closest component
				if ( bShouldSearchX || (!NoBorderX1 && !BorderComponent[0]))
				{
					NoBorderX1 = true;
					for (int32 X = ComponentIndexX-1; X >= ComponentIndexX1; X--)
					{
						BorderComponent[0] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X,ComponentIndexY));
						if (BorderComponent[0])
						{
							NoBorderX1 = false;
							NeighborTexDataInfo[0] = GetTextureDataInfo(BorderComponent[0]->HeightmapTexture);
							NeighborHeightmapTextureData[0] = (FColor*)NeighborTexDataInfo[0]->GetMipData(0);
							break;
						}
					}
				}
				// Search for right-closest component
				if ( bShouldSearchX || (!NoBorderX2 && !BorderComponent[1]))
				{
					NoBorderX2 = true;
					for (int32 X = ComponentIndexX+1; X <= ComponentIndexX2; X++)
					{
						BorderComponent[1] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X,ComponentIndexY));
						if (BorderComponent[1])
						{
							NoBorderX2 = false;
							NeighborTexDataInfo[1] = GetTextureDataInfo(BorderComponent[1]->HeightmapTexture);
							NeighborHeightmapTextureData[1] = (FColor*)NeighborTexDataInfo[1]->GetMipData(0);
							break;
						}
					}
				}
				// Search for up-closest component
				if ( bShouldSearchY || (!NoBorderY1[ComponentIndexXX] && !BorderComponentY1[ComponentIndexXX]))
				{
					NoBorderY1[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY-1; Y >= ComponentIndexY1; Y--)
					{
						BorderComponentY1[ComponentIndexXX] = BorderComponent[2] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,Y));
						if (BorderComponent[2])
						{
							NoBorderY1[ComponentIndexXX] = false;
							NeighborTexDataInfo[2] = GetTextureDataInfo(BorderComponent[2]->HeightmapTexture);
							NeighborHeightmapTextureData[2] = (FColor*)NeighborTexDataInfo[2]->GetMipData(0);
							break;
						}
					}
				}
				else
				{
					BorderComponent[2] = BorderComponentY1[ComponentIndexXX];
					if (BorderComponent[2])
					{
						NeighborTexDataInfo[2] = GetTextureDataInfo(BorderComponent[2]->HeightmapTexture);
						NeighborHeightmapTextureData[2] = (FColor*)NeighborTexDataInfo[2]->GetMipData(0);
					}
				}
				// Search for bottom-closest component
				if ( bShouldSearchY || (!NoBorderY2[ComponentIndexXX] && !BorderComponentY2[ComponentIndexXX]))
				{
					NoBorderY2[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY+1; Y <= ComponentIndexY2; Y++)
					{
						BorderComponentY2[ComponentIndexXX] = BorderComponent[3] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,Y));
						if (BorderComponent[3])
						{
							NoBorderY2[ComponentIndexXX] = false;
							NeighborTexDataInfo[3] = GetTextureDataInfo(BorderComponent[3]->HeightmapTexture);
							NeighborHeightmapTextureData[3] = (FColor*)NeighborTexDataInfo[3]->GetMipData(0);
							break;
						}
					}
				}
				else
				{
					BorderComponent[3] = BorderComponentY2[ComponentIndexXX];
					if (BorderComponent[3])
					{
						NeighborTexDataInfo[3] = GetTextureDataInfo(BorderComponent[3]->HeightmapTexture);
						NeighborHeightmapTextureData[3] = (FColor*)NeighborTexDataInfo[3]->GetMipData(0);
					}
				}

				CornerComponent[0] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX-1),(ComponentIndexY-1))) : NULL;
				CornerComponent[1] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX+1),(ComponentIndexY-1))) : NULL;
				CornerComponent[2] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX-1),(ComponentIndexY+1))) : NULL;
				CornerComponent[3] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX+1),(ComponentIndexY+1))) : NULL;

				if (CornerComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetHeightMapData(CornerComponent[0], EdgeCoord, EdgeCoord);
				}
				else if ((ExistLeft || ExistUp) && X1 <= ComponentIndexX*ComponentSizeQuads && Y1 <= ComponentIndexY*ComponentSizeQuads  )
				{
					CornerSet |= 1;
					CornerValues[0] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads);
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetHeightMapData(BorderComponent[0], EdgeCoord, 0, NeighborHeightmapTextureData[0]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1;
					CornerValues[0] = GetHeightMapData(BorderComponent[2], 0, EdgeCoord, NeighborHeightmapTextureData[2]);
				}

				if (CornerComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetHeightMapData(CornerComponent[1], 0, EdgeCoord);
				}
				else if (ExistUp && X2 >= (ComponentIndexX+1)*ComponentSizeQuads)
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = StoreData.Load( (ComponentIndexX+1)*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads);
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetHeightMapData(BorderComponent[1], 0, 0, NeighborHeightmapTextureData[1]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetHeightMapData(BorderComponent[2], EdgeCoord, EdgeCoord, NeighborHeightmapTextureData[2]);
				}

				if (CornerComponent[2])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetHeightMapData(CornerComponent[2], EdgeCoord, 0);
				}
				else if (ExistLeft && Y2 >= (ComponentIndexY+1)*ComponentSizeQuads) // Use data already stored for 0, 2
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, (ComponentIndexY+1)*ComponentSizeQuads);
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetHeightMapData(BorderComponent[0], EdgeCoord, EdgeCoord, NeighborHeightmapTextureData[0]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetHeightMapData(BorderComponent[3], 0, 0, NeighborHeightmapTextureData[3]);
				}

				if (CornerComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetHeightMapData(CornerComponent[3], 0, 0);
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetHeightMapData(BorderComponent[1], 0, EdgeCoord, NeighborHeightmapTextureData[1]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetHeightMapData(BorderComponent[3], EdgeCoord, 0, NeighborHeightmapTextureData[3]);
				}

				FillCornerValues(CornerSet, CornerValues);
				ComponentDataExist[ComponentIndexXY] = ExistLeft || ExistUp || (BorderComponent[0] || BorderComponent[1] || BorderComponent[2] || BorderComponent[3]) || CornerSet;
			}

			if (!ComponentDataExist[ComponentIndexXY])
			{
				continue;
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							// Find the input data corresponding to this vertex
							if( Component )
							{
								// Find the texture data corresponding to this vertex
								uint16 Height = GetHeightMapData(Component, (SubsectionSizeQuads+1) * SubIndexX + SubX, (SubsectionSizeQuads+1) * SubIndexY + SubY, HeightmapTextureData);
								StoreData.Store(LandscapeX, LandscapeY, Height);
							}
							else
							{
								// Find the texture data corresponding to this vertex
								uint16 Value[4] = {0, 0, 0, 0};
								int32 Dist[4] = {INT_MAX, INT_MAX, INT_MAX, INT_MAX};
								float ValueX = 0.0f, ValueY = 0.0f;
								bool Exist[4] = {false, false, false, false};

								// Use data already stored for 0, 2
								if (ExistLeft)
								{
									Value[0] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, LandscapeY);
									Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
									Exist[0] = true;
								}
								else if (BorderComponent[0])
								{
									Value[0] = GetHeightMapData(BorderComponent[0], EdgeCoord, (SubsectionSizeQuads+1) * SubIndexY + SubY, NeighborHeightmapTextureData[0]);
									Dist[0] = LandscapeX - (BorderComponent[0]->GetSectionBase().X + ComponentSizeQuads);
									Exist[0] = true;
								}
								else 
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 2))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
										Value[0] = (float)(Dist2 * CornerValues[0] + Dist1 * CornerValues[2]) / (Dist1 + Dist2);
										Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										Exist[0] = true;
									}
								}

								if (BorderComponent[1])
								{
									Value[1] = GetHeightMapData(BorderComponent[1], 0, (SubsectionSizeQuads+1) * SubIndexY + SubY, NeighborHeightmapTextureData[1]);
									Dist[1] = (BorderComponent[1]->GetSectionBase().X) - LandscapeX;
									Exist[1] = true;
								}
								else
								{
									if ((CornerSet & 1 << 1) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
										Value[1] = (float)(Dist2 * CornerValues[1] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[1] = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Exist[1] = true;
									}
								}

								if (ExistUp)
								{
									Value[2] = StoreData.Load( LandscapeX, ComponentIndexY*ComponentSizeQuads);
									Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
									Exist[2] = true;
								}
								else if (BorderComponent[2])
								{
									Value[2] = GetHeightMapData(BorderComponent[2], (SubsectionSizeQuads+1) * SubIndexX + SubX, EdgeCoord, NeighborHeightmapTextureData[2]);
									Dist[2] = LandscapeY - (BorderComponent[2]->GetSectionBase().Y + ComponentSizeQuads);
									Exist[2] = true;
								}
								else
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 1))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Value[2] = (float)(Dist2 * CornerValues[0] + Dist1 * CornerValues[1]) / (Dist1 + Dist2);
										Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										Exist[2] = true;
									}
								}

								if (BorderComponent[3])
								{
									Value[3] = GetHeightMapData(BorderComponent[3], (SubsectionSizeQuads+1) * SubIndexX + SubX, 0, NeighborHeightmapTextureData[3]);
									Dist[3] = (BorderComponent[3]->GetSectionBase().Y) - LandscapeY;
									Exist[3] = true;
								}
								else
								{
									if ((CornerSet & 1 << 2) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
										Value[3] = (float)(Dist2 * CornerValues[2] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[3] = (ComponentIndexY+1)*ComponentSizeQuads - LandscapeY;
										Exist[3] = true;
									}
								}

								CalcInterpValue<uint16>(Dist, Exist, Value, ValueX, ValueY);

								uint16 FinalValue = 0; // Default Value
								if ( (Exist[0] || Exist[1]) && (Exist[2] || Exist[3]) )
								{
									FinalValue = CalcValueFromValueXY<uint16>(Dist, ValueX, ValueY, CornerSet, CornerValues);
								}
								else if ( (BorderComponent[0] || BorderComponent[1]) )
								{
									FinalValue = ValueX;
								}
								else if ( (BorderComponent[2] || BorderComponent[3]) )
								{
									FinalValue = ValueY;
								}
								else if ( (Exist[0] || Exist[1]) )
								{
									FinalValue = ValueX;
								}
								else if ( (Exist[2] || Exist[3]) )
								{
									FinalValue = ValueY;
								}

								StoreData.Store(LandscapeX, LandscapeY, FinalValue);
								//StoreData.StoreDefault(LandscapeX, LandscapeY);
							}
						}
					}
				}
			}
		}
	}

	if (bHasMissingValue)
	{
		CalcMissingValues<uint16, TStoreData, float>( X1, X2, Y1, Y2,
			ComponentIndexX1, ComponentIndexX2, ComponentIndexY1, ComponentIndexY2, 
			ComponentSizeX, ComponentSizeY, CornerValues,
			NoBorderY1, NoBorderY2, ComponentDataExist, StoreData );
		// Update valid region
		ValidX1 = FMath::Max<int32>(X1, ValidX1);
		ValidX2 = FMath::Min<int32>(X2, ValidX2);
		ValidY1 = FMath::Max<int32>(Y1, ValidY1);
		ValidY2 = FMath::Min<int32>(Y2, ValidY2);
	}
	else
	{
		ValidX1 = X1;
		ValidX2 = X2;
		ValidY1 = Y1;
		ValidY2 = Y2;
	}
}

namespace
{
	struct FArrayStoreData
	{
		int32 X1;
		int32 Y1;
		uint16* Data;
		int32 Stride;

		FArrayStoreData(int32 InX1, int32 InY1, uint16* InData, int32 InStride)
			:	X1(InX1)
			,	Y1(InY1)
			,	Data(InData)
			,	Stride(InStride)
		{}

		inline void Store(int32 LandscapeX, int32 LandscapeY, uint16 Height)
		{
			Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ] = Height;
		}

		// for interpolation
		inline uint16 Load(int32 LandscapeX, int32 LandscapeY)
		{
			return Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ];
		}

		inline void StoreDefault(int32 LandscapeX, int32 LandscapeY)
		{
			Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ] = 0;
		}
	};

	struct FSparseStoreData
	{
		TMap<FIntPoint, uint16>& SparseData;

		FSparseStoreData(TMap<FIntPoint, uint16>& InSparseData)
			:	SparseData(InSparseData)
		{}

		inline void Store(int32 LandscapeX, int32 LandscapeY, uint16 Height)
		{
			SparseData.Add(FIntPoint(LandscapeX,LandscapeY), Height);
		}

		inline uint16 Load(int32 LandscapeX, int32 LandscapeY)
		{
			return SparseData.FindRef(FIntPoint(LandscapeX,LandscapeY));
		}

		inline void StoreDefault(int32 LandscapeX, int32 LandscapeY)
		{
		}
	};

};

void FLandscapeEditDataInterface::GetHeightData(int32& X1, int32& Y1, int32& X2, int32& Y2, uint16* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}

	FArrayStoreData ArrayStoreData(X1, Y1, Data, Stride);
	GetHeightDataTempl(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetHeightDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, uint16* Data, int32 Stride, uint16* NormalData /*= NULL*/)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}

	FArrayStoreData ArrayStoreData(X1, Y1, Data, Stride);
	if (NormalData)
	{
		FArrayStoreData ArrayNormalData(X1, Y1, NormalData, Stride);
		GetHeightDataTemplFast(X1, Y1, X2, Y2, ArrayStoreData, &ArrayNormalData);
	}
	else
	{
		GetHeightDataTemplFast(X1, Y1, X2, Y2, ArrayStoreData);
	}
}

void FLandscapeEditDataInterface::GetHeightData(int32& X1, int32& Y1, int32& X2, int32& Y2, TMap<FIntPoint, uint16>& SparseData)
{
	FSparseStoreData SparseStoreData(SparseData);
	GetHeightDataTempl(X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetHeightDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, uint16>& SparseData, TMap<FIntPoint, uint16>* NormalData /*= NULL*/)
{
	FSparseStoreData SparseStoreData(SparseData);
	if (NormalData)
	{
		FSparseStoreData SparseNormalData(*NormalData);
		GetHeightDataTemplFast(X1, Y1, X2, Y2, SparseStoreData, &SparseNormalData);
	}
	else
	{
		GetHeightDataTemplFast(X1, Y1, X2, Y2, SparseStoreData);
	}
}

void ULandscapeComponent::DeleteLayer(ULandscapeLayerInfoObject* LayerInfo, FLandscapeEditDataInterface& LandscapeEdit)
{
	ULandscapeComponent* Component = this;

	// Find the index for this layer in this component.
	const int32 DeleteLayerIdx = Component->WeightmapLayerAllocations.IndexOfByPredicate(
		[LayerInfo](const FWeightmapLayerAllocationInfo& Allocation) { return Allocation.LayerInfo == LayerInfo; });
	if (DeleteLayerIdx == INDEX_NONE)
	{
		// Layer not used for this component.
		return;
	}

	FWeightmapLayerAllocationInfo& DeleteLayerAllocation = Component->WeightmapLayerAllocations[DeleteLayerIdx];
	int32 DeleteLayerWeightmapTextureIndex = DeleteLayerAllocation.WeightmapTextureIndex;

	// See if we'll be able to remove the texture completely.
	bool bCanRemoveLayerTexture = true;
	for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
	{
		FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];

		// check if we will be able to remove the texture also
		if (LayerIdx != DeleteLayerIdx && Allocation.WeightmapTextureIndex == DeleteLayerWeightmapTextureIndex)
		{
			bCanRemoveLayerTexture = false;
		}
	}

	// See if the deleted layer is a NoWeightBlend layer - if not, we don't have to worry about normalization
	bool bDeleteLayerIsNoWeightBlend = (LayerInfo && LayerInfo->bNoWeightBlend);

	if (!bDeleteLayerIsNoWeightBlend)
	{
		// Lock data for all the weightmaps
		TArray<FLandscapeTextureDataInfo*> TexDataInfos;
		for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
		{
			TexDataInfos.Add(LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]));
		}

		TArray<bool> LayerNoWeightBlends;	// Array of NoWeightBlend flags
		TArray<uint8*> LayerDataPtrs;		// Pointers to all layers' data 

		// Get the data for each layer
		for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
		{
			FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
			LayerDataPtrs.Add((uint8*)TexDataInfos[Allocation.WeightmapTextureIndex]->GetMipData(0) + ChannelOffsets[Allocation.WeightmapTextureChannel]);

			// Find the layer info and record if it is a bNoWeightBlend layer.
			LayerNoWeightBlends.Add(Allocation.LayerInfo && Allocation.LayerInfo->bNoWeightBlend);
		}

		// Find the texture data corresponding to this vertex
		const int32 SizeU = (SubsectionSizeQuads + 1) * NumSubsections;
		const int32 SizeV = (SubsectionSizeQuads + 1) * NumSubsections;
		const int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
		const int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

		for (int32 SubIndexY = 0; SubIndexY < NumSubsections; SubIndexY++)
		{
			for (int32 SubIndexX = 0; SubIndexX < NumSubsections; SubIndexX++)
			{
				for (int32 SubY = 0; SubY <= SubsectionSizeQuads; SubY++)
				{
					for (int32 SubX = 0; SubX <= SubsectionSizeQuads; SubX++)
					{
						const int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads + 1) * SubIndexX + SubX;
						const int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads + 1) * SubIndexY + SubY;
						const int32 TexDataIndex = 4 * (TexX + TexY * SizeU);

						// Calculate the sum of other layer weights
						int32 OtherLayerWeightSum = 0;
						for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
						{
							if (LayerIdx != DeleteLayerIdx && LayerNoWeightBlends[LayerIdx] == false)
							{
								OtherLayerWeightSum += LayerDataPtrs[LayerIdx][TexDataIndex];
							}
						}

						if (OtherLayerWeightSum == 0)
						{
							// Set the first other weight-blend layer we can find to 255 to avoid a black hole
							// This isn't ideal but it's the best option
							// There's nothing we can easily do if this was the only weight-blend layer on this component
							for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
							{
								if (LayerIdx != DeleteLayerIdx && LayerNoWeightBlends[LayerIdx] == false)
								{
									uint8& Weight = LayerDataPtrs[LayerIdx][TexDataIndex];
									Weight = 255;
									break;
								}
							}
						}
						else
						{
							// Adjust other layer weights
							for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
							{
								if (LayerIdx != DeleteLayerIdx && LayerNoWeightBlends[LayerIdx] == false)
								{
									uint8& Weight = LayerDataPtrs[LayerIdx][TexDataIndex];
									Weight = FMath::Clamp<int32>(FMath::RoundToInt(255.0f * (float)Weight / (float)OtherLayerWeightSum), 0, 255);
								}
							}
						}
					}
				}
			}
		}

		// Update all the textures and mips
		for (int32 Idx = 0; Idx < Component->WeightmapTextures.Num(); Idx++)
		{
			if (bCanRemoveLayerTexture && Idx == DeleteLayerWeightmapTextureIndex)
			{
				// We're going to remove this texture anyway, so don't bother updating
				continue;
			}

			UTexture2D* WeightmapTexture = Component->WeightmapTextures[Idx];
			FLandscapeTextureDataInfo* WeightmapDataInfo = TexDataInfos[Idx];

			const int32 NumMips = WeightmapTexture->Source.GetNumMips();
			TArray<FColor*> WeightmapTextureMipData;
			WeightmapTextureMipData.AddUninitialized(NumMips);
			for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
			{
				WeightmapTextureMipData[MipIdx] = (FColor*)WeightmapDataInfo->GetMipData(MipIdx);
			}

			ULandscapeComponent::UpdateWeightmapMips(Component->NumSubsections, Component->SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, 0, 0, MAX_int32, MAX_int32, WeightmapDataInfo);

			WeightmapDataInfo->AddMipUpdateRegion(0, 0, 0, WeightmapTexture->Source.GetSizeX() - 1, WeightmapTexture->Source.GetSizeY() - 1);
		}
	}

	// Mark the channel as unallocated, so we can reuse it later
	ALandscapeProxy* Proxy = Component->GetLandscapeProxy();
	Component->Modify();
	Proxy->Modify();

	FLandscapeWeightmapUsage* Usage = Proxy->WeightmapUsageMap.Find(Component->WeightmapTextures[DeleteLayerAllocation.WeightmapTextureIndex]);
	if (Usage) // can be null if WeightmapUsageMap hasn't been built yet
	{
		Usage->ChannelUsage[DeleteLayerAllocation.WeightmapTextureChannel] = nullptr;
	}

	// Remove the layer
	Component->WeightmapLayerAllocations.RemoveAt(DeleteLayerIdx);

	// If this layer was the last usage for this channel in this layer, we can remove it.
	if (bCanRemoveLayerTexture)
	{
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->SetFlags(RF_Transactional);
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->Modify();
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->MarkPackageDirty();
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->ClearFlags(RF_Standalone);

		Component->WeightmapTextures.RemoveAt(DeleteLayerWeightmapTextureIndex);

		// Adjust WeightmapTextureIndex index for other layers
		for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
		{
			FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];

			if (Allocation.WeightmapTextureIndex > DeleteLayerWeightmapTextureIndex)
			{
				Allocation.WeightmapTextureIndex--;
			}

			check(Allocation.WeightmapTextureIndex < Component->WeightmapTextures.Num());
		}
	}

	// Update the shaders for this component
	Component->UpdateMaterialInstances();

	// Update dominant layer info stored in collision component
	TArray<FColor*> CollisionWeightmapMipData;
	for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
	{
		CollisionWeightmapMipData.Add((FColor*)LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->CollisionMipLevel));
	}
	TArray<FColor*> SimpleCollisionWeightmapMipData;
	if (Component->SimpleCollisionMipLevel > Component->CollisionMipLevel)
	{
		for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
		{
			SimpleCollisionWeightmapMipData.Add((FColor*)LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->SimpleCollisionMipLevel));
		}
	}
	Component->UpdateCollisionLayerData(
		CollisionWeightmapMipData.GetData(),
		Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? SimpleCollisionWeightmapMipData.GetData() : nullptr);
}

void FLandscapeEditDataInterface::DeleteLayer(ULandscapeLayerInfoObject* LayerInfo)
{
	if (!LandscapeInfo)
	{
		return;
	}

	for (auto& XYComponentPair : LandscapeInfo->XYtoComponentMap)
	{
		ULandscapeComponent* Component = XYComponentPair.Value;
		Component->DeleteLayer(LayerInfo, *this);
	}

	// Flush dynamic data (e.g. grass)
	TSet<ULandscapeComponent*> Components;
	Algo::Transform(LandscapeInfo->XYtoComponentMap, Components, &TPair<FIntPoint, ULandscapeComponent*>::Value);
	ALandscapeProxy::InvalidateGeneratedComponentData(Components);
}

void ULandscapeComponent::FillLayer(ULandscapeLayerInfoObject* LayerInfo, FLandscapeEditDataInterface& LandscapeEdit)
{
	check(LayerInfo);

	ULandscapeComponent* Component = this;

	ALandscapeProxy* Proxy = Component->GetLandscapeProxy();
	Component->Modify();
	Proxy->Modify();

	const bool bFillLayerIsNoWeightBlend = LayerInfo->bNoWeightBlend;
	bool bClearOtherWeightBlendLayers = !bFillLayerIsNoWeightBlend;

	// Find the index for this layer in this component.
	int32 FillLayerIdx = Component->WeightmapLayerAllocations.IndexOfByPredicate(
		[LayerInfo](const FWeightmapLayerAllocationInfo& Allocation) { return Allocation.LayerInfo == LayerInfo; });

	// if the layer isn't used on this component yet but is a weight-blend layer, then simply steal the allocation of another weight-blend layer!
	if (FillLayerIdx == INDEX_NONE && !bFillLayerIsNoWeightBlend)
	{
		FillLayerIdx = Component->WeightmapLayerAllocations.IndexOfByPredicate(
			[](const FWeightmapLayerAllocationInfo& Allocation) { return !Allocation.LayerInfo || !Allocation.LayerInfo->bNoWeightBlend; });

		if (FillLayerIdx != INDEX_NONE)
		{
			Component->WeightmapLayerAllocations[FillLayerIdx].LayerInfo = LayerInfo;
		}
		else
		{
			// no other weight-blend layers exist
			bClearOtherWeightBlendLayers = false;
		}
	}

	// if the layer is still not found then we are forced to make a new allocation
	if (FillLayerIdx == INDEX_NONE)
	{
		FillLayerIdx = Component->WeightmapLayerAllocations.Num();
		Component->WeightmapLayerAllocations.Add(FWeightmapLayerAllocationInfo(LayerInfo));
		Component->ReallocateWeightmaps(&LandscapeEdit);
	}

	check(FillLayerIdx != INDEX_NONE);

	// fill the layer
	{
		// Find the texture data corresponding to this vertex
		const int32 SizeU = (SubsectionSizeQuads + 1) * NumSubsections;
		const int32 SizeV = (SubsectionSizeQuads + 1) * NumSubsections;
		const int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
		const int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

		FWeightmapLayerAllocationInfo& FillLayerAllocation = Component->WeightmapLayerAllocations[FillLayerIdx];
		uint8* LayerData = (uint8*)LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[FillLayerAllocation.WeightmapTextureIndex])->GetMipData(0);

		for (int32 Y = 0; Y < SizeV; ++Y)
		{
			const int32 TexY = WeightmapOffsetY + Y;
			uint8* RowData = LayerData + ((WeightmapOffsetY + Y) * SizeU + WeightmapOffsetX) * 4 + ChannelOffsets[FillLayerAllocation.WeightmapTextureChannel];
			for (int32 X = 0; X < SizeU; ++X)
			{
				RowData[X * 4] = 255;
			}
		}
	}

	// clear other layers
	if (bClearOtherWeightBlendLayers)
	{
		for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); ++LayerIdx)
		{
			if (LayerIdx == FillLayerIdx)
			{
				continue;
			}
			FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
			if (Allocation.LayerInfo->bNoWeightBlend)
			{
				continue;
			}

			FLandscapeWeightmapUsage* Usage = Proxy->WeightmapUsageMap.Find(Component->WeightmapTextures[Allocation.WeightmapTextureIndex]);
			if (Usage) // can be null if WeightmapUsageMap hasn't been built yet
			{
				Usage->ChannelUsage[Allocation.WeightmapTextureChannel] = nullptr;
			}

			Allocation.WeightmapTextureIndex = 255;
		}

		Component->WeightmapLayerAllocations.RemoveAll(
			[](const FWeightmapLayerAllocationInfo& Allocation) { return Allocation.WeightmapTextureIndex == 255; });

		// remove any textures we're no longer using
		for (int32 TextureIdx = 0; TextureIdx < Component->WeightmapTextures.Num(); ++TextureIdx)
		{
			if (!Component->WeightmapLayerAllocations.ContainsByPredicate(
				[TextureIdx](const FWeightmapLayerAllocationInfo& Allocation) { return Allocation.WeightmapTextureIndex == TextureIdx; }))
			{
				Component->WeightmapTextures[TextureIdx]->Modify();

				for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); ++LayerIdx)
				{
					FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
					if (Allocation.WeightmapTextureIndex > TextureIdx)
					{
						--Allocation.WeightmapTextureIndex;
					}
				}

				Component->WeightmapTextures.RemoveAt(TextureIdx--);
			}
		}
	}

	// todo - normalize texture usage: it's possible to end up with two textures each using one channel at this point
	// e.g. if you start with 4 blended layers (in one texture) and a non-blended layer (in a 2nd), and fill one weight-blended layer (deleting the other three)
	// this can also happen with normal painting I believe

	// update mips
	for (int32 TextureIdx = 0; TextureIdx < Component->WeightmapTextures.Num(); ++TextureIdx)
	{
		UTexture2D* WeightmapTexture = WeightmapTextures[TextureIdx];
		FLandscapeTextureDataInfo* WeightmapDataInfo = LandscapeEdit.GetTextureDataInfo(WeightmapTexture);

		const int32 NumMips = WeightmapTexture->Source.GetNumMips();
		TArray<FColor*> WeightmapTextureMipData;
		WeightmapTextureMipData.AddUninitialized(NumMips);
		for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
		{
			WeightmapTextureMipData[MipIdx] = (FColor*)WeightmapDataInfo->GetMipData(MipIdx);
		}

		ULandscapeComponent::UpdateWeightmapMips(NumSubsections, SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, 0, 0, MAX_int32, MAX_int32, WeightmapDataInfo);

		WeightmapDataInfo->AddMipUpdateRegion(0, 0, 0, WeightmapTexture->Source.GetSizeX() - 1, WeightmapTexture->Source.GetSizeY() - 1);
	}

	// Update the shaders for this component
	Component->UpdateMaterialInstances();

	Component->InvalidateLightingCache();

	// Update dominant layer info stored in collision component
	TArray<FColor*> CollisionWeightmapMipData;
	for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
	{
		CollisionWeightmapMipData.Add((FColor*)LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->CollisionMipLevel));
	}
	TArray<FColor*> SimpleCollisionWeightmapMipData;
	if (Component->SimpleCollisionMipLevel > Component->CollisionMipLevel)
	{
		for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
		{
			SimpleCollisionWeightmapMipData.Add((FColor*)LandscapeEdit.GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->SimpleCollisionMipLevel));
		}
	}
	Component->UpdateCollisionLayerData(
		CollisionWeightmapMipData.GetData(),
		Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? SimpleCollisionWeightmapMipData.GetData() : nullptr);
}

void FLandscapeEditDataInterface::FillLayer(ULandscapeLayerInfoObject* LayerInfo)
{
	if (!LandscapeInfo)
	{
		return;
	}

	LayerInfo->IsReferencedFromLoadedData = true;

	for (auto& XYComponentPair : LandscapeInfo->XYtoComponentMap)
	{
		ULandscapeComponent* Component = XYComponentPair.Value;
		Component->FillLayer(LayerInfo, *this);
	}	

	// Flush dynamic data (e.g. grass)
	TSet<ULandscapeComponent*> Components;
	for (auto& XYComponentPair : LandscapeInfo->XYtoComponentMap)
	{
		Components.Add(XYComponentPair.Value);
	}
	ALandscapeProxy::InvalidateGeneratedComponentData(Components);
}

void FLandscapeEditDataInterface::FillEmptyLayers(ULandscapeLayerInfoObject* LayerInfo)
{
	if (!LandscapeInfo)
	{
		return;
	}

	LayerInfo->IsReferencedFromLoadedData = true;

	for (auto& XYComponentPair : LandscapeInfo->XYtoComponentMap)
	{
		ULandscapeComponent* Component = XYComponentPair.Value;

		if (Component->WeightmapLayerAllocations.Num() == 0)
		{
			Component->FillLayer(LayerInfo, *this);
		}
	}

	// Flush dynamic data (e.g. grass)
	TSet<ULandscapeComponent*> Components;
	for (auto& XYComponentPair : LandscapeInfo->XYtoComponentMap)
	{
		Components.Add(XYComponentPair.Value);
	}
	ALandscapeProxy::InvalidateGeneratedComponentData(Components);
}

void ULandscapeComponent::ReplaceLayer(ULandscapeLayerInfoObject* FromLayerInfo, ULandscapeLayerInfoObject* ToLayerInfo, FLandscapeEditDataInterface& LandscapeEdit)
{
	check(FromLayerInfo && ToLayerInfo);
	if (FromLayerInfo == ToLayerInfo)
	{
		return;
	}

	// Find the index for this layer in this component.
	int32 FromLayerIdx = INDEX_NONE;
	for (int32 LayerIdx = 0; LayerIdx < WeightmapLayerAllocations.Num(); LayerIdx++)
	{
		FWeightmapLayerAllocationInfo& Allocation = WeightmapLayerAllocations[LayerIdx];
		if (Allocation.LayerInfo == FromLayerInfo)
		{
			FromLayerIdx = LayerIdx;
		}
	}
	if (FromLayerIdx == INDEX_NONE)
	{
		// Layer not used for this component, nothing to do.
		return;
	}

	bool bMerging = true;

	// Find the index for this layer in this component.
	int32 ToLayerIdx = INDEX_NONE;
	for (int32 LayerIdx = 0; LayerIdx < WeightmapLayerAllocations.Num(); LayerIdx++)
	{
		FWeightmapLayerAllocationInfo& Allocation = WeightmapLayerAllocations[LayerIdx];
		if (Allocation.LayerInfo == ToLayerInfo)
		{
			ToLayerIdx = LayerIdx;
		}
	}
	if (ToLayerIdx == INDEX_NONE)
	{
		// Layer not used for this component, so do trivial replace.
		WeightmapLayerAllocations[FromLayerIdx].LayerInfo = ToLayerInfo;
		bMerging = false;
	}

	FWeightmapLayerAllocationInfo& FromLayerAllocation = WeightmapLayerAllocations[FromLayerIdx];

	// See if we'll be able to remove the texture completely.
	bool bCanRemoveLayerTexture = false;
	if (bMerging)
	{
		bCanRemoveLayerTexture = true;
		for (int32 LayerIdx = 0; LayerIdx < WeightmapLayerAllocations.Num(); LayerIdx++)
		{
			FWeightmapLayerAllocationInfo& Allocation = WeightmapLayerAllocations[LayerIdx];

			// check if we will be able to remove the texture also
			if (LayerIdx != FromLayerIdx && Allocation.WeightmapTextureIndex == FromLayerAllocation.WeightmapTextureIndex)
			{
				bCanRemoveLayerTexture = false;
				break;
			}
		}
	}

	// See if the deleted layer is a NoWeightBlend layer - if not, we don't have to worry about normalization
	const bool bFromLayerIsNoWeightBlend = (FromLayerInfo && FromLayerInfo->bNoWeightBlend);
	const bool bToLayerIsNoWeightBlend = (ToLayerInfo && ToLayerInfo->bNoWeightBlend);

	const bool bRequireNormalization = (bFromLayerIsNoWeightBlend != bToLayerIsNoWeightBlend);
	checkf(!bRequireNormalization, TEXT("It is not yet supported to replace a layer with another whose bNoWeightBlend setting does not match"))

	if (bMerging)
	{
		FWeightmapLayerAllocationInfo& ToLayerAllocation = WeightmapLayerAllocations[ToLayerIdx];

		// Lock data for all the weightmaps
		FLandscapeTextureDataInfo* FromTexDataInfo = LandscapeEdit.GetTextureDataInfo(WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]);
		FLandscapeTextureDataInfo* ToTexDataInfo = LandscapeEdit.GetTextureDataInfo(WeightmapTextures[ToLayerAllocation.WeightmapTextureIndex]);

		check(FromTexDataInfo->GetMipSizeX(0) == FromTexDataInfo->GetMipSizeY(0));
		check(ToTexDataInfo->GetMipSizeX(0) == ToTexDataInfo->GetMipSizeY(0));
		check(FromTexDataInfo->GetMipSizeX(0) == ToTexDataInfo->GetMipSizeX(0));
		const int32 MipSize = FromTexDataInfo->GetMipSizeX(0);

		uint8* const SrcTextureData = (uint8*)FromTexDataInfo->GetMipData(0) + ChannelOffsets[FromLayerAllocation.WeightmapTextureChannel];
		uint8* const DestTextureData = (uint8*)ToTexDataInfo->GetMipData(0) + ChannelOffsets[ToLayerAllocation.WeightmapTextureChannel];

		for (int32 i = 0; i < FMath::Square(MipSize); i++)
		{
			DestTextureData[i*4] = FMath::Min(255, (uint16)DestTextureData[i*4] + (uint16)SrcTextureData[i*4]);
		}

		// Update all mips
		if (!bCanRemoveLayerTexture)
		{
			UTexture2D* WeightmapTexture = WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex];
			FLandscapeTextureDataInfo* WeightmapDataInfo = FromTexDataInfo;

			const int32 NumMips = WeightmapTexture->Source.GetNumMips();
			TArray<FColor*> WeightmapTextureMipData;
			WeightmapTextureMipData.AddUninitialized(NumMips);
			for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
			{
				WeightmapTextureMipData[MipIdx] = (FColor*)WeightmapDataInfo->GetMipData(MipIdx);
			}

			ULandscapeComponent::UpdateWeightmapMips(NumSubsections, SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, 0, 0, MAX_int32, MAX_int32, WeightmapDataInfo);

			WeightmapDataInfo->AddMipUpdateRegion(0, 0, 0, WeightmapTexture->Source.GetSizeX() - 1, WeightmapTexture->Source.GetSizeY() - 1);
		}

		if (FromTexDataInfo != ToTexDataInfo)
		{
			UTexture2D* WeightmapTexture = WeightmapTextures[ToLayerAllocation.WeightmapTextureIndex];
			FLandscapeTextureDataInfo* WeightmapDataInfo = ToTexDataInfo;

			const int32 NumMips = WeightmapTexture->Source.GetNumMips();
			TArray<FColor*> WeightmapTextureMipData;
			WeightmapTextureMipData.AddUninitialized(NumMips);
			for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
			{
				WeightmapTextureMipData[MipIdx] = (FColor*)WeightmapDataInfo->GetMipData(MipIdx);
			}

			ULandscapeComponent::UpdateWeightmapMips(NumSubsections, SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, 0, 0, MAX_int32, MAX_int32, WeightmapDataInfo);

			WeightmapDataInfo->AddMipUpdateRegion(0, 0, 0, WeightmapTexture->Source.GetSizeX() - 1, WeightmapTexture->Source.GetSizeY() - 1);
		}
	}

	if (bRequireNormalization)
	{
		// TODO
	}

	// if merging into an existing layer, remove the layer and potentially the texture
	if (bMerging)
	{
		ALandscapeProxy* Proxy = GetLandscapeProxy();
		// Mark the channel as unallocated, so we can reuse it later
		FLandscapeWeightmapUsage* Usage = Proxy->WeightmapUsageMap.Find(WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]);
		//check(Usage);
		if (Usage)
		{
			Usage->ChannelUsage[FromLayerAllocation.WeightmapTextureChannel] = NULL;
		}

		// If this layer was the last usage for this texture, we can remove it.
		if (bCanRemoveLayerTexture)
		{
			WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]->SetFlags(RF_Transactional);
			WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]->Modify();
			WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]->MarkPackageDirty();
			WeightmapTextures[FromLayerAllocation.WeightmapTextureIndex]->ClearFlags(RF_Standalone);

			WeightmapTextures.RemoveAt(FromLayerAllocation.WeightmapTextureIndex);

			// Adjust WeightmapTextureIndex index for other layers
			for (int32 LayerIdx = 0; LayerIdx < WeightmapLayerAllocations.Num(); LayerIdx++)
			{
				if (LayerIdx == FromLayerIdx)
				{
					continue;
				}

				FWeightmapLayerAllocationInfo& Allocation = WeightmapLayerAllocations[LayerIdx];

				if (Allocation.WeightmapTextureIndex > FromLayerAllocation.WeightmapTextureIndex)
				{
					Allocation.WeightmapTextureIndex--;
				}

				check(Allocation.WeightmapTextureIndex < WeightmapTextures.Num());
			}
		}

		// Remove the layer
		WeightmapLayerAllocations.RemoveAt(FromLayerIdx);

		// Update the shaders for this component
		UpdateMaterialInstances();
	}
}

void FLandscapeEditDataInterface::ReplaceLayer(ULandscapeLayerInfoObject* FromLayerInfo, ULandscapeLayerInfoObject* ToLayerInfo)
{
	if (!LandscapeInfo) return;
	for( auto It = LandscapeInfo->XYtoComponentMap.CreateIterator(); It; ++It )
	{
		ULandscapeComponent* Component = It.Value();
		Component->ReplaceLayer(FromLayerInfo, ToLayerInfo, *this);

		// Update dominant layer info stored in collision component
		TArray<FColor*> CollisionWeightmapMipData;
		for( int32 WeightmapIdx=0;WeightmapIdx < Component->WeightmapTextures.Num();WeightmapIdx++ )
		{
			CollisionWeightmapMipData.Add((FColor*)GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->CollisionMipLevel));
		}
		TArray<FColor*> SimpleCollisionWeightmapMipData;
		if (Component->SimpleCollisionMipLevel > Component->CollisionMipLevel)
		{
			for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
			{
				SimpleCollisionWeightmapMipData.Add((FColor*)GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx])->GetMipData(Component->SimpleCollisionMipLevel));
			}
		}
		Component->UpdateCollisionLayerData(
			CollisionWeightmapMipData.GetData(),
			Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? SimpleCollisionWeightmapMipData.GetData() : nullptr);
	}
}

// simple classes for the template....
namespace
{
	template<typename TDataType>
	struct TArrayStoreData
	{
		int32 X1;
		int32 Y1;
		TDataType* Data;
		int32 Stride;
		int32 ArraySize;

		TArrayStoreData(int32 InX1, int32 InY1, TDataType* InData, int32 InStride)
			:	X1(InX1)
			,	Y1(InY1)
			,	Data(InData)
			,	Stride(InStride)
			,	ArraySize(1)
		{}

		inline void Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight) {}
		inline void Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight, int32 LayerIdx) {}
		inline void Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset) {}
		inline TDataType Load(int32 LandscapeX, int32 LandscapeY) { return 0; }
		inline void PreInit(int32 InArraySize) { ArraySize = InArraySize; }
	};

	template<> void TArrayStoreData<uint8>::Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight)
	{
		Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ] = Weight;
	}

	template<> uint8 TArrayStoreData<uint8>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ];
	}

	template<> FVector2D TArrayStoreData<FVector2D>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return Data[(LandscapeY - Y1) * Stride + (LandscapeX - X1)];
	}

	template<> FVector TArrayStoreData<FVector>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return Data[(LandscapeY - Y1) * Stride + (LandscapeX - X1)];
	}

	template<> void TArrayStoreData<FVector2D>::Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset)
	{
		Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ] = Offset;
	}

	template<> void TArrayStoreData<FVector>::Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset)
	{
		Data[ (LandscapeY-Y1) * Stride + (LandscapeX-X1) ] = FVector(Offset.X, Offset.Y, 0.0f);
	}

	// Data items should be initialized with ArraySize
	template<> void TArrayStoreData<TArray<uint8>>::Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight, int32 LayerIdx)
	{
		TArray<uint8>& Value = Data[ ((LandscapeY-Y1) * Stride + (LandscapeX-X1)) ];
		if (Value.Num() != ArraySize)
		{
			Value.Empty(ArraySize);
			Value.AddZeroed(ArraySize);
		}
		Value[LayerIdx] = Weight;
	}

	template<typename TDataType>
	struct TSparseStoreData
	{
		TMap<FIntPoint, TDataType>& SparseData;
		int32 ArraySize;

		TSparseStoreData(TMap<FIntPoint, TDataType>& InSparseData)
			:	SparseData(InSparseData)
			,	ArraySize(1)
		{}

		inline void Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight) {}
		inline void Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight, int32 LayerIdx) {}
		inline void Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset) {}
		inline TDataType Load(int32 LandscapeX, int32 LandscapeY) { return 0; }
		inline void PreInit(int32 InArraySize) { ArraySize = InArraySize; }
	};

	template<> void TSparseStoreData<uint8>::Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight)
	{
		SparseData.Add(FIntPoint(LandscapeX,LandscapeY), Weight);
	}

	template<> uint8 TSparseStoreData<uint8>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return SparseData.FindRef(FIntPoint(LandscapeX,LandscapeY));
	}

	template<> FVector2D TSparseStoreData<FVector2D>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return SparseData.FindRef(FIntPoint(LandscapeX, LandscapeY));
	}

	template<> FVector TSparseStoreData<FVector>::Load(int32 LandscapeX, int32 LandscapeY)
	{
		return SparseData.FindRef(FIntPoint(LandscapeX, LandscapeY));
	}

	template<> void TSparseStoreData<TArray<uint8>>::Store(int32 LandscapeX, int32 LandscapeY, uint8 Weight, int32 LayerIdx)
	{
		TArray<uint8>* Value = SparseData.Find(FIntPoint(LandscapeX,LandscapeY));
		if (Value)
		{
			(*Value)[LayerIdx] = Weight;
		}
		else
		{
			TArray<uint8> Values;
			Values.Empty(ArraySize);
			Values.AddZeroed(ArraySize);
			Values[LayerIdx] = Weight;
			SparseData.Add(FIntPoint(LandscapeX, LandscapeY), Values);
		}
	}

	template<> void TSparseStoreData<FVector2D>::Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset)
	{
		SparseData.Add(FIntPoint(LandscapeX,LandscapeY), Offset);
	}

	template<> void TSparseStoreData<FVector>::Store(int32 LandscapeX, int32 LandscapeY, FVector2D Offset)
	{
		// Preserve old Z value
		FVector* PrevValue = SparseData.Find(FIntPoint(LandscapeX,LandscapeY));
		if (PrevValue != NULL)
		{
			PrevValue->X = Offset.X;
			PrevValue->Y = Offset.Y;
		}
		else
		{
			SparseData.Add(FIntPoint(LandscapeX,LandscapeY), FVector(Offset.X, Offset.Y, 0.0f));
		}
	}
};

bool DeleteLayerIfAllZero(ULandscapeComponent* const Component, const uint8* const TexDataPtr, int32 TexSize, int32 LayerIdx)
{
	// Check the data for the entire component and to see if it's all zero
	for (int32 TexY = 0; TexY < TexSize; TexY++)
	{
		for (int32 TexX = 0; TexX < TexSize; TexX++)
		{
			const int32 TexDataIndex = 4 * (TexX + TexY * TexSize);

			// Stop the first time we see any non-zero data
			uint8 Weight = TexDataPtr[TexDataIndex];
			if (Weight != 0)
			{
				return false;
			}
		}
	}

	ALandscapeProxy* Proxy = Component->GetLandscapeProxy();
	Component->Modify();
	Proxy->Modify();

	// Mark the channel as unallocated, so we can reuse it later
	const int32 DeleteLayerWeightmapTextureIndex = Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex;
	FLandscapeWeightmapUsage& Usage = Proxy->WeightmapUsageMap.FindChecked(Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]);
	Usage.ChannelUsage[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel] = NULL;

	// Remove the layer as it's totally painted away.
	Component->WeightmapLayerAllocations.RemoveAt(LayerIdx);

	// Check if the weightmap texture used by the layer we just removed is used by any other layer, and if so, remove the texture too
	bool bCanRemoveLayerTexture = !Component->WeightmapLayerAllocations.ContainsByPredicate([DeleteLayerWeightmapTextureIndex](const FWeightmapLayerAllocationInfo& Allocation){ return Allocation.WeightmapTextureIndex == DeleteLayerWeightmapTextureIndex; });
	if (bCanRemoveLayerTexture)
	{
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->MarkPackageDirty();
		Component->WeightmapTextures[DeleteLayerWeightmapTextureIndex]->ClearFlags(RF_Standalone);
		Component->WeightmapTextures.RemoveAt(DeleteLayerWeightmapTextureIndex);

		// Adjust WeightmapTextureChannel index for other layers
		for (auto It = Component->WeightmapLayerAllocations.CreateIterator(); It; ++It)
		{
			FWeightmapLayerAllocationInfo& Allocation = *It;
			if (Allocation.WeightmapTextureIndex > DeleteLayerWeightmapTextureIndex)
			{
				Allocation.WeightmapTextureIndex--;
			}
		}
	}

	return true;
}


inline bool FLandscapeEditDataInterface::IsWhitelisted(const ULandscapeLayerInfoObject* const LayerInfo, const int32 ComponentIndexX, const int32 SubIndexX, const int32 SubX, const int32 ComponentIndexY, const int32 SubIndexY, const int32 SubY)
{
	// left / right
	if (SubIndexX == 0 && SubX == 0)
	{
		ULandscapeComponent* EdgeComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX - 1, ComponentIndexY));
		if (EdgeComponent && !EdgeComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}
	else if (SubIndexX == ComponentNumSubsections - 1 && SubX == SubsectionSizeQuads)
	{
		ULandscapeComponent* EdgeComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX + 1, ComponentIndexY));
		if (EdgeComponent && !EdgeComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}

	// up / down
	if (SubIndexY == 0 && SubY == 0)
	{
		ULandscapeComponent* EdgeComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, ComponentIndexY - 1));
		if (EdgeComponent && !EdgeComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}
	else if (SubIndexY == ComponentNumSubsections - 1 && SubY == SubsectionSizeQuads)
	{
		ULandscapeComponent* EdgeComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, ComponentIndexY + 1));
		if (EdgeComponent && !EdgeComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}

	// diagonals
	if (SubIndexY == 0 && SubY == 0 && SubIndexX == 0 && SubX == 0)
	{
		ULandscapeComponent* CornerComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX - 1, ComponentIndexY - 1));
		if (CornerComponent && !CornerComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}
	else if (SubIndexY == 0 && SubY == 0 && SubIndexX == ComponentNumSubsections - 1 && SubX == SubsectionSizeQuads)
	{
		ULandscapeComponent* CornerComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX + 1, ComponentIndexY - 1));
		if (CornerComponent && !CornerComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}
	else if (SubIndexY == ComponentNumSubsections - 1 && SubY == SubsectionSizeQuads && SubIndexX == 0 && SubX == 0)
	{
		ULandscapeComponent* CornerComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX - 1, ComponentIndexY + 1));
		if (CornerComponent && !CornerComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}
	else if (SubIndexY == ComponentNumSubsections - 1 && SubY == SubsectionSizeQuads && SubIndexX == ComponentNumSubsections - 1 && SubX == SubsectionSizeQuads)
	{
		ULandscapeComponent* CornerComponent = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX + 1, ComponentIndexY + 1));
		if (CornerComponent && !CornerComponent->LayerWhitelist.Contains(LayerInfo))
		{
			return false;
		}
	}

	return true;
}

inline TMap<const ULandscapeLayerInfoObject*, uint32> FLandscapeEditDataInterface::CountWeightBlendedLayerInfluence(const int32 ComponentIndexX, const int32 ComponentIndexY, TOptional<TArrayView<const uint8* const>> InOptionalLayerDataPtrs)
{
	// the counts should easily fit in a uint32, a 255x255 x2x2 Component with weights of all 255 only totals 26 bits
	checkSlow(FMath::CeilLogTwo(ComponentSizeQuads + 1) * 2 + 8 /*ceillog2(255)*/ <= 32);
	TMap<const ULandscapeLayerInfoObject*, uint32> LayerInfluenceMap;

	ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindChecked(FIntPoint(ComponentIndexX,ComponentIndexY));

	// used if InOptionalLayerDataPtrs is null
	TArray<FLandscapeTextureDataInfo*, TInlineAllocator<2>> InternalTexDataInfos;
	TArray<const uint8*, TInlineAllocator<8>> InternalLayerDataPtrs;
	TArrayView<const uint8* const> LayerDataPtrs;
	if (InOptionalLayerDataPtrs)
	{
		check(InOptionalLayerDataPtrs->Num() == Component->WeightmapLayerAllocations.Num());
		LayerDataPtrs = InOptionalLayerDataPtrs.GetValue();
	}
	else
	{
		InternalTexDataInfos.AddUninitialized(Component->WeightmapTextures.Num());
		for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); ++WeightmapIdx)
		{
			InternalTexDataInfos[WeightmapIdx] = GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]);
		}

		InternalLayerDataPtrs.AddUninitialized(Component->WeightmapLayerAllocations.Num());
		for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
		{
			const FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
			InternalLayerDataPtrs[LayerIdx] = (uint8*)InternalTexDataInfos[Allocation.WeightmapTextureIndex]->GetMipData(0) + ChannelOffsets[Allocation.WeightmapTextureChannel];
		}

		LayerDataPtrs = InternalLayerDataPtrs;
	}

	const int32 ScanlineSize = (SubsectionSizeQuads + 1) * ComponentNumSubsections * 4;

	for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
	{
		const FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
		if (Allocation.LayerInfo->bNoWeightBlend)
		{
			continue;
		}
		auto& Count = LayerInfluenceMap.Add(Allocation.LayerInfo, 0);

		for (int32 SubIndexY = 0; SubIndexY < ComponentNumSubsections; ++SubIndexY)
		{
			const int32 YStart = SubIndexY * (SubsectionSizeQuads + 1);
			const int32 YEnd = YStart + (SubsectionSizeQuads + 1);
			for (int32 Y = YStart; Y < YEnd; ++Y)
			{
				for (int32 SubIndexX = 0; SubIndexX < ComponentNumSubsections; ++SubIndexX)
				{
					const int32 XStart = SubIndexX * (SubsectionSizeQuads + 1);
					const int32 XEnd = XStart + (SubsectionSizeQuads + 1);
					for (int32 X = XStart; X < XEnd; ++X)
					{
						const int32 TexDataIndex = Y * ScanlineSize + X * 4;
						const uint8 Weight = LayerDataPtrs[LayerIdx][TexDataIndex];
						Count += Weight;
					}
				}
			}
		}
	}

	LayerInfluenceMap.ValueSort(TGreater<uint32>());
	return LayerInfluenceMap;
}

const ULandscapeLayerInfoObject* FLandscapeEditDataInterface::ChooseReplacementLayer(const ULandscapeLayerInfoObject* const LayerInfo, const int32 ComponentIndexX, const int32 SubIndexX, const int32 SubX, const int32 ComponentIndexY, const int32 SubIndexY, const int32 SubY, TMap<FIntPoint, TMap<const ULandscapeLayerInfoObject*, uint32>>& LayerInfluenceCache, TArrayView<const uint8* const> LayerDataPtrs)
{
	const TMap<const ULandscapeLayerInfoObject*, uint32>* LayerInfluenceMapCacheEntry = LayerInfluenceCache.Find(FIntPoint(ComponentIndexX, ComponentIndexY));
	if (!LayerInfluenceMapCacheEntry)
	{
		LayerInfluenceMapCacheEntry = &LayerInfluenceCache.Add(FIntPoint(ComponentIndexX, ComponentIndexY), CountWeightBlendedLayerInfluence(ComponentIndexX, ComponentIndexY, LayerDataPtrs));
	}

	if (!(SubIndexX == 0 && SubX == 0) &&
		!(SubIndexX == ComponentNumSubsections - 1 && SubX == SubsectionSizeQuads) &&
		!(SubIndexY == 0 && SubY == 0) &&
		!(SubIndexY == ComponentNumSubsections - 1 && SubY == SubsectionSizeQuads))
	{
		for (const auto& LayerInfluenceMapPair : *LayerInfluenceMapCacheEntry)
		{
			if (LayerInfluenceMapPair.Key != LayerInfo)
			{
				return LayerInfluenceMapPair.Key;
			}
		}
		return nullptr;
	}

	TMap<const ULandscapeLayerInfoObject*, uint32, TInlineSetAllocator<8>> LayerInfluenceMap = *LayerInfluenceMapCacheEntry;

	const int32 ComponentXStart = (SubIndexX == 0 && SubX == 0) ? ComponentIndexX - 1 : ComponentIndexX;
	const int32 ComponentXEnd = (SubIndexX == ComponentNumSubsections - 1 && SubX == SubsectionSizeQuads) ? ComponentIndexX + 1 : ComponentIndexX;
	const int32 ComponentYStart = (SubIndexY == 0 && SubY == 0) ? ComponentIndexY - 1 : ComponentIndexY;
	const int32 ComponentYEnd = (SubIndexY == ComponentNumSubsections - 1 && SubY == SubsectionSizeQuads) ? ComponentIndexY + 1 : ComponentIndexY;
	for (int32 Y = ComponentYStart; Y <= ComponentYEnd; ++Y)
	{
		for (int32 X = ComponentXStart; X <= ComponentXEnd; ++X)
		{
			if (X == ComponentIndexX && Y == ComponentIndexY)
			{
				// skip the current component, it is already included above
				continue;
			}

			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X, Y));
			if (!Component)
			{
				// skip missing components
				continue;
			}

			const TMap<const ULandscapeLayerInfoObject*, uint32>* OtherLayerInfluenceMapCacheEntry = LayerInfluenceCache.Find(FIntPoint(X, Y));
			if (!OtherLayerInfluenceMapCacheEntry)
			{
				OtherLayerInfluenceMapCacheEntry = &LayerInfluenceCache.Add(FIntPoint(X, Y), CountWeightBlendedLayerInfluence(X, Y, {}));
			}

			for (auto LayerInfluenceMapIt = LayerInfluenceMap.CreateIterator(); LayerInfluenceMapIt; ++LayerInfluenceMapIt)
			{
				const uint32* Value = OtherLayerInfluenceMapCacheEntry->Find(LayerInfluenceMapIt->Key);
				if (Value)
				{
					LayerInfluenceMapIt->Value += *Value;
				}
				else
				{
					// only allow layers that exist in *all* the touched components
					LayerInfluenceMapIt.RemoveCurrent();
				}
			}
		}
	}

	LayerInfluenceMap.ValueSort(TGreater<uint32>());
	for (const auto& LayerInfluenceMapPair : LayerInfluenceMap)
	{
		if (LayerInfluenceMapPair.Key != LayerInfo)
		{
			return LayerInfluenceMapPair.Key;
		}
	}
	return nullptr;
}

void FLandscapeEditDataInterface::SetAlphaData(ULandscapeLayerInfoObject* const LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, const uint8* Data, int32 Stride, ELandscapeLayerPaintingRestriction PaintingRestriction /*= None*/, bool bWeightAdjust /*= true*/, bool bTotalWeightAdjust /*= false*/)
{
	check(LayerInfo != NULL);
	if (LayerInfo->bNoWeightBlend)
	{
		bWeightAdjust = false;
	}

	if (Stride == 0)
	{
		Stride = (1+X2-X1);
	}

	check(ComponentSizeQuads > 0);
	// Find component range for this block of data
	int32 ComponentIndexX1 = (X1-1 >= 0) ? (X1-1) / ComponentSizeQuads : (X1) / ComponentSizeQuads - 1;	// -1 because we need to pick up vertices shared between components
	int32 ComponentIndexY1 = (Y1-1 >= 0) ? (Y1-1) / ComponentSizeQuads : (Y1) / ComponentSizeQuads - 1;
	int32 ComponentIndexX2 = (X2 >= 0) ? X2 / ComponentSizeQuads : (X2+1) / ComponentSizeQuads - 1;
	int32 ComponentIndexY2 = (Y2 >= 0) ? Y2 / ComponentSizeQuads : (Y2+1) / ComponentSizeQuads - 1;

	TArray<FLandscapeTextureDataInfo*, TInlineAllocator<2>> TexDataInfos;
	TArray<uint8*, TInlineAllocator<8>> LayerDataPtrs;      // Pointers to all layers' data
	TArray<bool, TInlineAllocator<8>> LayerNoWeightBlends;  // NoWeightBlend flags
	TArray<bool, TInlineAllocator<8>> LayerEditDataAllZero; // Whether the data we are editing for this layer is all zero
	TArray<FColor*> CollisionWeightmapMipData;
	TArray<FColor*> SimpleCollisionWeightmapMipData;
	TArray<FColor*> WeightmapTextureMipData;

	TMap<FIntPoint, TMap<const ULandscapeLayerInfoObject*, uint32>> LayerInfluenceCache;

	for (int32 ComponentIndexY = ComponentIndexY1; ComponentIndexY <= ComponentIndexY2; ComponentIndexY++)
	{
		for (int32 ComponentIndexX = ComponentIndexX1; ComponentIndexX <= ComponentIndexX2; ComponentIndexX++)
		{
			FIntPoint ComponentKey(ComponentIndexX,ComponentIndexY);
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(ComponentKey);

			// if NULL, there is no component at this location
			if (Component == NULL)
			{
				continue;
			}

			if (PaintingRestriction == ELandscapeLayerPaintingRestriction::UseComponentWhitelist && !Component->LayerWhitelist.Contains(LayerInfo))
			{
				continue;
			}

			Component->Modify();

			int32 UpdateLayerIdx = Component->WeightmapLayerAllocations.IndexOfByPredicate([LayerInfo](const FWeightmapLayerAllocationInfo& Allocation){ return Allocation.LayerInfo == LayerInfo; });

			// Need allocation for weightmap
			if (UpdateLayerIdx == INDEX_NONE)
			{
				const int32 LayerLimit = Component->GetLandscapeProxy()->MaxPaintedLayersPerComponent;

				// if we can't allocate a layer, then there is nothing to paint
				if (PaintingRestriction == ELandscapeLayerPaintingRestriction::ExistingOnly ||
					(PaintingRestriction == ELandscapeLayerPaintingRestriction::UseMaxLayers && LayerLimit > 0 && Component->WeightmapLayerAllocations.Num() >= LayerLimit))
				{
					continue;
				}

				UpdateLayerIdx = Component->WeightmapLayerAllocations.Num();
				new (Component->WeightmapLayerAllocations) FWeightmapLayerAllocationInfo(LayerInfo);
				Component->ReallocateWeightmaps(this);

				Component->UpdateMaterialInstances();

				Component->EditToolRenderData.UpdateDebugColorMaterial(Component);

				Component->UpdateEditToolRenderData();
			}

			// Lock data for all the weightmaps
			TexDataInfos.Reset();
			TexDataInfos.AddUninitialized(Component->WeightmapTextures.Num());

			for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); ++WeightmapIdx)
			{
				TexDataInfos[WeightmapIdx] = GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]);
			}

			LayerDataPtrs.Reset();        // Pointers to all layers' data
			LayerDataPtrs.AddUninitialized(Component->WeightmapLayerAllocations.Num());
			LayerNoWeightBlends.Reset();  // NoWeightBlend flags
			LayerNoWeightBlends.AddUninitialized(Component->WeightmapLayerAllocations.Num());
			LayerEditDataAllZero.Reset(); // Whether the data we are editing for this layer is all zero 
			LayerEditDataAllZero.AddUninitialized(Component->WeightmapLayerAllocations.Num());

			for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
			{
				FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
				LayerDataPtrs[LayerIdx] = (uint8*)TexDataInfos[Allocation.WeightmapTextureIndex]->GetMipData(0) + ChannelOffsets[Allocation.WeightmapTextureChannel];
				LayerNoWeightBlends[LayerIdx] = Allocation.LayerInfo->bNoWeightBlend;
				LayerEditDataAllZero[LayerIdx] = true;
			}

			// Find the texture data corresponding to this vertex
			const int32 TexSize = (SubsectionSizeQuads+1) * ComponentNumSubsections;

			// Find coordinates of box that lies inside component
			const int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			const int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads, 0, ComponentNumSubsections-1); // -1 because we need to pick up vertices shared between subsections
			const int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads, 0, ComponentNumSubsections-1);
			const int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads, 0, ComponentNumSubsections-1);
			const int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads, 0, ComponentNumSubsections-1);

			for (int32 SubIndexY = SubIndexY1; SubIndexY <= SubIndexY2; SubIndexY++)
			{
				for (int32 SubIndexX = SubIndexX1; SubIndexX <= SubIndexX2; SubIndexX++)
				{
					// Find coordinates of box that lies inside subsection
					const int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					const int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					const int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					const int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for (int32 SubY = SubY1; SubY <= SubY2; SubY++)
					{
						for (int32 SubX = SubX1; SubX <= SubX2; SubX++)
						{
							const int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							const int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;
							checkSlow( LandscapeX >= X1 && LandscapeX <= X2 );
							checkSlow( LandscapeY >= Y1 && LandscapeY <= Y2 );

							// Find the input data corresponding to this vertex
							const int32 DataIndex = (LandscapeX-X1) + Stride * (LandscapeY-Y1);
							uint8 NewWeight = Data[DataIndex];

							const int32 TexX = (SubsectionSizeQuads+1) * SubIndexX + SubX;
							const int32 TexY = (SubsectionSizeQuads+1) * SubIndexY + SubY;
							const int32 TexDataIndex = 4 * (TexX + TexY * TexSize);

							uint8 CurrentWeight = LayerDataPtrs[UpdateLayerIdx][TexDataIndex];
							if (NewWeight == CurrentWeight)
							{
								continue;
							}

							if (PaintingRestriction == ELandscapeLayerPaintingRestriction::UseComponentWhitelist && NewWeight != 0)
							{
								bool bWhitelisted = IsWhitelisted(LayerInfo, ComponentIndexX, SubIndexX, SubX, ComponentIndexY, SubIndexY, SubY);
								if (!bWhitelisted)
								{
									NewWeight = 0;
								}
							}

							// Adjust all layer weights
							// (bWeightAdjust implies that this is a weight-blended layer)
							int32 OtherLayerWeightSum = 0;
							if (bWeightAdjust)
							{
								// Normalize all layers including the painted one
								// gmartin: this isn't used. TODO: Remove
								if (bTotalWeightAdjust)
								{
									int32 MaxLayerIdx = -1;
									int32 MaxWeight = INT_MIN;

									// Adjust other layers' weights accordingly
									for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
									{
										uint8& ExistingWeight = LayerDataPtrs[LayerIdx][TexDataIndex];

										if (LayerIdx == UpdateLayerIdx)
										{
											ExistingWeight = NewWeight;
										}
										// Exclude bNoWeightBlend layers
										if (LayerNoWeightBlends[LayerIdx] == false)
										{
											OtherLayerWeightSum += ExistingWeight;
											if (MaxWeight < ExistingWeight)
											{
												MaxWeight = ExistingWeight;
												MaxLayerIdx = LayerIdx;
											}
										}
									}

									if (OtherLayerWeightSum != 255)
									{
										const float Factor = 255.0f / OtherLayerWeightSum;
										OtherLayerWeightSum = 0;

										// Normalize
										for (int32 LayerIdx = 0; LayerIdx<Component->WeightmapLayerAllocations.Num(); LayerIdx++)
										{
											uint8& ExistingWeight = LayerDataPtrs[LayerIdx][TexDataIndex];

											if (LayerNoWeightBlends[LayerIdx] == false)
											{
												// normalization...
												ExistingWeight = (uint8)(Factor * ExistingWeight);
												OtherLayerWeightSum += ExistingWeight;

												if (ExistingWeight != 0)
												{
													LayerEditDataAllZero[LayerIdx] = false;
												}
											}
										}

										if ((255 - OtherLayerWeightSum) && MaxLayerIdx >= 0)
										{
											LayerDataPtrs[MaxLayerIdx][TexDataIndex] += 255 - OtherLayerWeightSum;
										}
									}
								}
								else
								{
									// Adjust other layers' weights accordingly
									for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
									{
										const uint8 ExistingWeight = LayerDataPtrs[LayerIdx][TexDataIndex];
										// Exclude bNoWeightBlend layers
										if (LayerIdx != UpdateLayerIdx && LayerNoWeightBlends[LayerIdx] == false)
										{
											OtherLayerWeightSum += ExistingWeight;
										}
									}

									if (OtherLayerWeightSum == 0 && NewWeight < 255)
									{
										if (NewWeight < CurrentWeight)
										{
											// When reducing the layer weight from 255, we need to choose another layer to fill to avoid a black hole
											const ULandscapeLayerInfoObject* ReplacementLayer = ChooseReplacementLayer(LayerInfo, ComponentIndexX, SubIndexX, SubX, ComponentIndexY, SubIndexY, SubY, LayerInfluenceCache, LayerDataPtrs);
											if (ReplacementLayer)
											{
												const int32 ReplacementLayerIndex = Component->WeightmapLayerAllocations.IndexOfByPredicate([&](const FWeightmapLayerAllocationInfo& AllocationInfo) { return AllocationInfo.LayerInfo == ReplacementLayer; });

												LayerDataPtrs[ReplacementLayerIndex][TexDataIndex] = 255 - NewWeight;
												LayerEditDataAllZero[ReplacementLayerIndex] = false;
											}
											else
											{
												// if we didn't find a suitable replacement we just have to leave it at 255, unfortunately
												NewWeight = 255;
											}
										}
										else if (NewWeight > CurrentWeight)
										{
											// if weight is increasing on a black spot then go straight to 255
											NewWeight = 255;
										}

										LayerDataPtrs[UpdateLayerIdx][TexDataIndex] = NewWeight;
									}
									else
									{
										for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
										{
											uint8& Weight = LayerDataPtrs[LayerIdx][TexDataIndex];

											if (LayerIdx == UpdateLayerIdx)
											{
												Weight = NewWeight;
											}
											else
											{
												// Exclude bNoWeightBlend layers
												if (LayerNoWeightBlends[LayerIdx] == false)
												{
													Weight = FMath::Clamp<uint8>(FMath::RoundToInt((float)(255 - NewWeight) * (float)Weight / (float)OtherLayerWeightSum), 0, 255);
												}
											}

											if (Weight != 0)
											{
												LayerEditDataAllZero[LayerIdx] = false;
											}
										}
									}
								}
							}
							else
							{
								// Weight value set without adjusting other layers' weights
								uint8& Weight = LayerDataPtrs[UpdateLayerIdx][TexDataIndex];
								Weight = NewWeight;
								if (Weight != 0)
								{
									LayerEditDataAllZero[UpdateLayerIdx] = false;
								}
							}
						}
					}

					// Record the areas of the texture we need to re-upload
					const int32 TexX1 = (SubsectionSizeQuads+1) * SubIndexX + SubX1;
					const int32 TexY1 = (SubsectionSizeQuads+1) * SubIndexY + SubY1;
					const int32 TexX2 = (SubsectionSizeQuads+1) * SubIndexX + SubX2;
					const int32 TexY2 = (SubsectionSizeQuads+1) * SubIndexY + SubY2;
					for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
					{
						if (TexDataInfos[WeightmapIdx] != NULL)
						{
							TexDataInfos[WeightmapIdx]->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);
						}
					}
				}
			}

			// Update mipmaps
			CollisionWeightmapMipData.Reset();
			CollisionWeightmapMipData.AddUninitialized(Component->WeightmapTextures.Num());
			for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
			{
				UTexture2D* const WeightmapTexture = Component->WeightmapTextures[WeightmapIdx];

				const int32 NumMips = WeightmapTexture->Source.GetNumMips();
				WeightmapTextureMipData.Reset();
				WeightmapTextureMipData.AddUninitialized(NumMips);
				for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
				{
					FColor* const MipData = (FColor*)TexDataInfos[WeightmapIdx]->GetMipData(MipIdx);
					WeightmapTextureMipData[MipIdx] = MipData;
				}
				CollisionWeightmapMipData[WeightmapIdx] = WeightmapTextureMipData[Component->CollisionMipLevel];

				ULandscapeComponent::UpdateWeightmapMips(ComponentNumSubsections, SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, ComponentX1, ComponentY1, ComponentX2, ComponentY2, TexDataInfos[WeightmapIdx]);
				WeightmapTextureMipData.Reset();
			}

			if (Component->SimpleCollisionMipLevel > Component->CollisionMipLevel)
			{
				for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
				{
					SimpleCollisionWeightmapMipData.Add((FColor*)TexDataInfos[WeightmapIdx]->GetMipData(Component->SimpleCollisionMipLevel));
				}
			}

			// Update dominant layer info stored in collision component
			Component->UpdateCollisionLayerData(
				CollisionWeightmapMipData.GetData(),
				Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? SimpleCollisionWeightmapMipData.GetData() : nullptr,
				ComponentX1, ComponentY1, ComponentX2, ComponentY2);
			CollisionWeightmapMipData.Reset();
			SimpleCollisionWeightmapMipData.Reset();

			// Check if we need to remove weightmap allocations for layers that were completely painted away
			bool bRemovedLayer = false;
			for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
			{
				if (LayerEditDataAllZero[LayerIdx])
				{
					bool bLayerDeleted = DeleteLayerIfAllZero(Component, LayerDataPtrs[LayerIdx], TexSize, LayerIdx);

					if (bLayerDeleted)
					{
						LayerEditDataAllZero.RemoveAt(LayerIdx);
						LayerDataPtrs.RemoveAt(LayerIdx);
						LayerIdx--;

						bRemovedLayer = true;
					}
				}
			}

			if (bRemovedLayer)
			{
				Component->UpdateMaterialInstances();

				Component->EditToolRenderData.UpdateDebugColorMaterial(Component);

				Component->UpdateEditToolRenderData();
			}
		}
	}
}

void FLandscapeEditDataInterface::SetAlphaData(const TSet<ULandscapeLayerInfoObject*>& DirtyLayerInfos, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, const uint8* Data, int32 Stride, ELandscapeLayerPaintingRestriction PaintingRestriction /*= None*/)
{
	if (DirtyLayerInfos.Num() == 0)
	{
		return;
	}

	for (ULandscapeLayerInfoObject* LayerInfo : DirtyLayerInfos)
	{
		// The Data[] array passed in is indexed by LandscapeInfo->GetLayerInfoIndex(),
		// so if we're trying to write a layer which isn't in the LandscapeInfo,
		// its data is either missing or written where another layer's data should be.
		// Either way it's *very bad*.
		check(LandscapeInfo->GetLayerInfoIndex(LayerInfo) != INDEX_NONE);
	}

	if (Stride == 0)
	{
		Stride = (1+X2-X1) * LandscapeInfo->Layers.Num();
	}

	check(ComponentSizeQuads > 0);
	// Find component range for this block of data
	int32 ComponentIndexX1 = (X1-1 >= 0) ? (X1-1) / ComponentSizeQuads : (X1) / ComponentSizeQuads - 1;	// -1 because we need to pick up vertices shared between components
	int32 ComponentIndexY1 = (Y1-1 >= 0) ? (Y1-1) / ComponentSizeQuads : (Y1) / ComponentSizeQuads - 1;
	int32 ComponentIndexX2 = (X2 >= 0) ? X2 / ComponentSizeQuads : (X2+1) / ComponentSizeQuads - 1;
	int32 ComponentIndexY2 = (Y2 >= 0) ? Y2 / ComponentSizeQuads : (Y2+1) / ComponentSizeQuads - 1;

	TArray<ULandscapeLayerInfoObject*, TInlineAllocator<8>> NeedAllocationInfos;
	TArray<FLandscapeTextureDataInfo*, TInlineAllocator<2>> TexDataInfos;

	struct FLayerDataInfo
	{
		const uint8* InDataPtr;
		uint8* TexDataPtr;
	};

	TArray<FLayerDataInfo, TInlineAllocator<8>> LayerDataInfos;		// Pointers to all layers' data 
	TArray<bool, TInlineAllocator<8>> LayerEditDataAllZero; // Whether the data we are editing for this layer is all zero 
	TArray<FColor*> CollisionWeightmapMipData;
	TArray<FColor*> SimpleCollisionWeightmapMipData;
	TArray<FColor*> WeightmapTextureMipData;

	for (int32 ComponentIndexY = ComponentIndexY1; ComponentIndexY <= ComponentIndexY2; ComponentIndexY++)
	{
		for (int32 ComponentIndexX = ComponentIndexX1; ComponentIndexX <= ComponentIndexX2; ComponentIndexX++)
		{
			FIntPoint ComponentKey(ComponentIndexX,ComponentIndexY);
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(ComponentKey);

			// if NULL, there is no component at this location
			if (Component == NULL)
			{
				continue;
			}

			const int32 LayerLimit = Component->GetLandscapeProxy()->MaxPaintedLayersPerComponent;

			NeedAllocationInfos.Reset();

			for (ULandscapeLayerInfoObject* LayerInfo : DirtyLayerInfos)
			{
				const bool bFound = Component->WeightmapLayerAllocations.ContainsByPredicate([LayerInfo](const FWeightmapLayerAllocationInfo& Allocation){ return Allocation.LayerInfo == LayerInfo; });
				if (!bFound)
				{
					NeedAllocationInfos.Add(LayerInfo);
				}
			}

			// Need allocation for weightmaps
			if (NeedAllocationInfos.Num() > 0)
			{
				if (NeedAllocationInfos.Num() == DirtyLayerInfos.Num())
				{
					if (PaintingRestriction == ELandscapeLayerPaintingRestriction::ExistingOnly ||
						(PaintingRestriction == ELandscapeLayerPaintingRestriction::UseMaxLayers &&
						 Component->WeightmapLayerAllocations.Num() >= LayerLimit))
					{
						// nothing to paint to this component due to layer limit
						continue;
					}
				}
				if (PaintingRestriction != ELandscapeLayerPaintingRestriction::ExistingOnly)
				{
					Component->Modify();
					for (ULandscapeLayerInfoObject* LayerInfoNeedingAllocation : NeedAllocationInfos)
					{
						if (PaintingRestriction == ELandscapeLayerPaintingRestriction::UseMaxLayers &&
							LayerLimit > 0 && Component->WeightmapLayerAllocations.Num() >= LayerLimit)
						{
							break;
						}
						Component->WeightmapLayerAllocations.Emplace(LayerInfoNeedingAllocation);
					}
					Component->ReallocateWeightmaps(this);
					Component->UpdateMaterialInstances();
					
					Component->EditToolRenderData.UpdateDebugColorMaterial(Component);

					Component->UpdateEditToolRenderData();
				}
			}

			// Lock data for all the weightmaps
			TexDataInfos.Reset();
			TexDataInfos.AddUninitialized(Component->WeightmapTextures.Num());

			for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); ++WeightmapIdx)
			{
				TexDataInfos[WeightmapIdx] = GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]);
			}

			LayerDataInfos.Reset();        // Pointers to all layers' data
			LayerDataInfos.AddUninitialized(Component->WeightmapLayerAllocations.Num());
			LayerEditDataAllZero.Reset(); // Whether the data we are editing for this layer is all zero 
			LayerEditDataAllZero.AddUninitialized(Component->WeightmapLayerAllocations.Num());

			for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
			{
				FWeightmapLayerAllocationInfo& Allocation = Component->WeightmapLayerAllocations[LayerIdx];
				const int32 LayerDataIdx = LandscapeInfo->GetLayerInfoIndex(Component->WeightmapLayerAllocations[LayerIdx].LayerInfo);
				check(LayerDataIdx != INDEX_NONE);
				LayerDataInfos[LayerIdx].InDataPtr = Data + LayerDataIdx;
				LayerDataInfos[LayerIdx].TexDataPtr = (uint8*)TexDataInfos[Allocation.WeightmapTextureIndex]->GetMipData(0) + ChannelOffsets[Allocation.WeightmapTextureChannel];
				LayerEditDataAllZero[LayerIdx] = true;
			}

			// Find the texture data corresponding to this vertex
			const int32 TexSize = (Component->SubsectionSizeQuads+1) * Component->NumSubsections; 

			// Find coordinates of box that lies inside component
			const int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			const int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			const int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			const int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			const int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			const int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for (int32 SubIndexY = SubIndexY1; SubIndexY <= SubIndexY2; SubIndexY++)
			{
				for (int32 SubIndexX = SubIndexX1; SubIndexX <= SubIndexX2; SubIndexX++)
				{
					// Find coordinates of box that lies inside subsection
					const int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					const int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					const int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					const int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for (int32 SubY = SubY1; SubY <= SubY2; SubY++)
					{
						for (int32 SubX = SubX1; SubX <= SubX2; SubX++)
						{
							const int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							const int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;
							checkSlow( LandscapeX >= X1 && LandscapeX <= X2 );
							checkSlow( LandscapeY >= Y1 && LandscapeY <= Y2 );

							// Find the input data corresponding to this vertex
							const int32 DataIndex = (LandscapeY-Y1) * Stride + (LandscapeX-X1) * LandscapeInfo->Layers.Num();

							// Adjust all layer weights
							const int32 TexX = (SubsectionSizeQuads+1) * SubIndexX + SubX;
							const int32 TexY = (SubsectionSizeQuads+1) * SubIndexY + SubY;

							const int32 TexDataIndex = 4 * (TexX + TexY * TexSize);

							int32 OtherLayerWeightSum = 0;

							// Apply weights to all layers simultaneously.
							for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
							{
								// this is equivalent to saying if (DirtyLayerInfos.Contains(Allocation.LayerInfo))
								// which is what we really mean here, but this is quicker
								// and I've lost count of the depth we've nested for loops at this point
								if (LayerDataInfos[LayerIdx].TexDataPtr != NULL)
								{
									uint8& Weight = LayerDataInfos[LayerIdx].TexDataPtr[TexDataIndex];

									Weight = LayerDataInfos[LayerIdx].InDataPtr[DataIndex]; // Only for whole weight
									if (Weight != 0)
									{
										LayerEditDataAllZero[LayerIdx] = false;
									}
								}
							}
						}
					}

					// Record the areas of the texture we need to re-upload
					const int32 TexX1 = (SubsectionSizeQuads+1) * SubIndexX + SubX1;
					const int32 TexY1 = (SubsectionSizeQuads+1) * SubIndexY + SubY1;
					const int32 TexX2 = (SubsectionSizeQuads+1) * SubIndexX + SubX2;
					const int32 TexY2 = (SubsectionSizeQuads+1) * SubIndexY + SubY2;
					for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
					{
						if (TexDataInfos[WeightmapIdx] != NULL)
						{
							TexDataInfos[WeightmapIdx]->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);
						}
					}
				}
			}

			// Update mipmaps
			CollisionWeightmapMipData.Reset();
			CollisionWeightmapMipData.AddUninitialized(Component->WeightmapTextures.Num());
			for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
			{
				UTexture2D* const WeightmapTexture = Component->WeightmapTextures[WeightmapIdx];

				const int32 NumMips = WeightmapTexture->Source.GetNumMips();
				WeightmapTextureMipData.Reset();
				WeightmapTextureMipData.AddUninitialized(NumMips);
				for (int32 MipIdx = 0; MipIdx < NumMips; MipIdx++)
				{
					FColor* const MipData = (FColor*)TexDataInfos[WeightmapIdx]->GetMipData(MipIdx);
					WeightmapTextureMipData[MipIdx] = MipData;
				}
				CollisionWeightmapMipData[WeightmapIdx] = WeightmapTextureMipData[Component->CollisionMipLevel];

				ULandscapeComponent::UpdateWeightmapMips(ComponentNumSubsections, SubsectionSizeQuads, WeightmapTexture, WeightmapTextureMipData, ComponentX1, ComponentY1, ComponentX2, ComponentY2, TexDataInfos[WeightmapIdx]);
				WeightmapTextureMipData.Reset();
			}

			if (Component->SimpleCollisionMipLevel > Component->CollisionMipLevel)
			{
				for (int32 WeightmapIdx = 0; WeightmapIdx < Component->WeightmapTextures.Num(); WeightmapIdx++)
				{
					SimpleCollisionWeightmapMipData.Add((FColor*)TexDataInfos[WeightmapIdx]->GetMipData(Component->SimpleCollisionMipLevel));
				}
			}

			// Update dominant layer info stored in collision component
			Component->UpdateCollisionLayerData(
				CollisionWeightmapMipData.GetData(),
				Component->SimpleCollisionMipLevel > Component->CollisionMipLevel ? SimpleCollisionWeightmapMipData.GetData() : nullptr,
				ComponentX1, ComponentY1, ComponentX2, ComponentY2);
			CollisionWeightmapMipData.Reset();
			SimpleCollisionWeightmapMipData.Reset();

			// Check if we need to remove weightmap allocations for layers that were completely painted away
			bool bRemovedLayer = false;
			for (int32 LayerIdx = 0; LayerIdx < Component->WeightmapLayerAllocations.Num(); LayerIdx++)
			{
				if (LayerEditDataAllZero[LayerIdx])
				{
					bool bLayerDeleted = DeleteLayerIfAllZero(Component, LayerDataInfos[LayerIdx].TexDataPtr, TexSize, LayerIdx);

					if (bLayerDeleted)
					{
						LayerEditDataAllZero.RemoveAt(LayerIdx);
						LayerDataInfos.RemoveAt(LayerIdx);
						LayerIdx--;

						bRemovedLayer = true;
					}
				}
			}

			if (bRemovedLayer)
			{
				Component->UpdateMaterialInstances();

				Component->EditToolRenderData.UpdateDebugColorMaterial(Component);

				Component->UpdateEditToolRenderData();
			}
		}
	}
}

template<typename TStoreData>
void FLandscapeEditDataInterface::GetWeightDataTemplFast(ULandscapeLayerInfoObject* LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TStoreData& StoreData)
{
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{		
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			if( !Component )
			{
				continue;
			}

			UTexture2D* WeightmapTexture = NULL;
			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			uint8* WeightmapTextureData = NULL;
			uint8 WeightmapChannelOffset = 0;
			TArray<FLandscapeTextureDataInfo*> TexDataInfos; // added for whole weight case...

			if (LayerInfo != NULL)
			{
				for( int32 LayerIdx=0;LayerIdx<Component->WeightmapLayerAllocations.Num();LayerIdx++ )
				{
					if( Component->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
					{
						WeightmapTexture = Component->WeightmapTextures[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
						TexDataInfo = GetTextureDataInfo(WeightmapTexture);
						WeightmapTextureData = (uint8*)TexDataInfo->GetMipData(0);
						WeightmapChannelOffset = ChannelOffsets[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
						break;
					}
				}
			}
			else
			{
				// Lock data for all the weightmaps
				for( int32 WeightmapIdx=0;WeightmapIdx < Component->WeightmapTextures.Num();WeightmapIdx++ )
				{
					TexDataInfos.Add(GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]));
				}
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							if (LayerInfo != NULL)
							{
								// Find the input data corresponding to this vertex
								uint8 Weight;
								if( WeightmapTexture )
								{
									// Find the texture data corresponding to this vertex
									int32 SizeU = WeightmapTexture->Source.GetSizeX();
									int32 SizeV = WeightmapTexture->Source.GetSizeY();
									int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
									int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

									int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
									int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
									Weight = WeightmapTextureData[ 4 * (TexX + TexY * SizeU) + WeightmapChannelOffset ];
								}
								else
								{
									Weight = 0;
								}

								StoreData.Store(LandscapeX, LandscapeY, Weight);
							}
							else // Whole weight map case...
							{
								StoreData.PreInit(LandscapeInfo->Layers.Num());
								for( int32 LayerIdx=0;LayerIdx<Component->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									int32 Idx = Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex;
									UTexture2D* ComponentWeightmapTexture = Component->WeightmapTextures[Idx];
									uint8* ComponentWeightmapTextureData = (uint8*)TexDataInfos[Idx]->GetMipData(0);
									uint8 ComponentWeightmapChannelOffset = ChannelOffsets[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];

									// Find the texture data corresponding to this vertex
									int32 SizeU = ComponentWeightmapTexture->Source.GetSizeX();
									int32 SizeV = ComponentWeightmapTexture->Source.GetSizeY();
									int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
									int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

									int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
									int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;

									uint8 Weight = ComponentWeightmapTextureData[ 4 * (TexX + TexY * SizeU) + ComponentWeightmapChannelOffset ];

									// Find index in LayerInfos
									{
										int32 LayerInfoIdx = LandscapeInfo->GetLayerInfoIndex(Component->WeightmapLayerAllocations[LayerIdx].LayerInfo);
										if (LayerInfoIdx != INDEX_NONE)
										{
											StoreData.Store(LandscapeX, LandscapeY, Weight, LayerInfoIdx);
										}
									}
								}
							}
						}
					}
				}
			}
		}
	}
}

uint8 FLandscapeEditDataInterface::GetWeightMapData(const ULandscapeComponent* Component, ULandscapeLayerInfoObject* LayerInfo, int32 TexU, int32 TexV, uint8 Offset /*= 0*/, UTexture2D* Texture /*= NULL*/, uint8* TextureData /*= NULL*/)
{
	check(Component);
	if (!Texture || !TextureData)
	{
		if (LayerInfo != NULL)
		{
			for( int32 LayerIdx=0;LayerIdx<Component->WeightmapLayerAllocations.Num();LayerIdx++ )
			{
				if( Component->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
				{
					Texture = Component->WeightmapTextures[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
					FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(Texture);
					TextureData = (uint8*)TexDataInfo->GetMipData(0);
					Offset = ChannelOffsets[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
					break;
				}
			}
		}
	}

	if (Texture && TextureData)
	{
		int32 SizeU = Texture->Source.GetSizeX();
		int32 SizeV = Texture->Source.GetSizeY();
		int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
		int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

		int32 TexX = WeightmapOffsetX + TexU;
		int32 TexY = WeightmapOffsetY + TexV;
		return TextureData[ 4 * (TexX + TexY * SizeU) + Offset ];
	}
	return 0;
}

template<typename TStoreData>
void FLandscapeEditDataInterface::GetWeightDataTempl(ULandscapeLayerInfoObject* LayerInfo, int32& ValidX1, int32& ValidY1, int32& ValidX2, int32& ValidY2, TStoreData& StoreData)
{
	// Copy variables
	int32 X1 = ValidX1, X2 = ValidX2, Y1 = ValidY1, Y2 = ValidY2;
	ValidX1 = INT_MAX; ValidX2 = INT_MIN; ValidY1 = INT_MAX; ValidY2 = INT_MIN;

	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	int32 ComponentSizeX = ComponentIndexX2-ComponentIndexX1+1;
	int32 ComponentSizeY = ComponentIndexY2-ComponentIndexY1+1;

	// Neighbor Components
	ULandscapeComponent* BorderComponent[4] = {0, 0, 0, 0};
	ULandscapeComponent* CornerComponent[4] = {0, 0, 0, 0};
	bool NoBorderX1 = false, NoBorderX2 = false;
	TArray<bool> NoBorderY1, NoBorderY2, ComponentDataExist;
	TArray<ULandscapeComponent*> BorderComponentY1, BorderComponentY2;
	ComponentDataExist.Empty(ComponentSizeX*ComponentSizeY);
	ComponentDataExist.AddZeroed(ComponentSizeX*ComponentSizeY);
	bool bHasMissingValue = false;

	UTexture2D* NeighborWeightmapTexture[4] = {0, 0, 0, 0};
	FLandscapeTextureDataInfo* NeighborTexDataInfo[4] = {0, 0, 0, 0};
	uint8* NeighborWeightmapTextureData[4] = {0, 0, 0, 0};
	uint8 NeighborWeightmapChannelOffset[4] = {0, 0, 0, 0};
	uint8 CornerValues[4] = {0, 0, 0, 0};
	int32 EdgeCoord = (SubsectionSizeQuads+1) * ComponentNumSubsections - 1; //ComponentSizeQuads;

	// initial loop....
	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		NoBorderX1 = false;
		NoBorderX2 = false;
		BorderComponent[0] = BorderComponent[1] = NULL;
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{	
			BorderComponent[2] = BorderComponent[3] = NULL;
			int32 ComponentIndexXY = ComponentSizeX*(ComponentIndexY-ComponentIndexY1) + ComponentIndexX-ComponentIndexX1;
			int32 ComponentIndexXX = ComponentIndexX - ComponentIndexX1;
			int32 ComponentIndexYY = ComponentIndexY - ComponentIndexY1;
			ComponentDataExist[ComponentIndexXY] = false;
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			UTexture2D* WeightmapTexture = NULL;
			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			uint8* WeightmapTextureData = NULL;
			uint8 WeightmapChannelOffset = 0;
			TArray<FLandscapeTextureDataInfo*> TexDataInfos; // added for whole weight case...
			uint8 CornerSet = 0;
			bool ExistLeft = ComponentIndexXX > 0 && ComponentDataExist[ ComponentIndexXX-1 + ComponentIndexYY * ComponentSizeX ];
			bool ExistUp = ComponentIndexYY > 0 && ComponentDataExist[ ComponentIndexXX + (ComponentIndexYY-1) * ComponentSizeX ];

			if( Component )
			{
				if (LayerInfo != NULL)
				{
					for( int32 LayerIdx=0;LayerIdx<Component->WeightmapLayerAllocations.Num();LayerIdx++ )
					{
						if( Component->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
						{
							WeightmapTexture = Component->WeightmapTextures[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
							TexDataInfo = GetTextureDataInfo(WeightmapTexture);
							WeightmapTextureData = (uint8*)TexDataInfo->GetMipData(0);
							WeightmapChannelOffset = ChannelOffsets[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
							break;
						}
					}
				}
				else
				{
					// Lock data for all the weightmaps
					for( int32 WeightmapIdx=0;WeightmapIdx < Component->WeightmapTextures.Num();WeightmapIdx++ )
					{
						TexDataInfos.Add(GetTextureDataInfo(Component->WeightmapTextures[WeightmapIdx]));
					}
				}
				ComponentDataExist[ComponentIndexXY] = true;
				// Update valid region
				ValidX1 = FMath::Min<int32>(Component->GetSectionBase().X, ValidX1);
				ValidX2 = FMath::Max<int32>(Component->GetSectionBase().X+ComponentSizeQuads, ValidX2);
				ValidY1 = FMath::Min<int32>(Component->GetSectionBase().Y, ValidY1);
				ValidY2 = FMath::Max<int32>(Component->GetSectionBase().Y+ComponentSizeQuads, ValidY2);
			}
			else
			{
				if (!bHasMissingValue)
				{
					NoBorderY1.Empty(ComponentSizeX);
					NoBorderY2.Empty(ComponentSizeX);
					NoBorderY1.AddZeroed(ComponentSizeX);
					NoBorderY2.AddZeroed(ComponentSizeX);
					BorderComponentY1.Empty(ComponentSizeX);
					BorderComponentY2.Empty(ComponentSizeX);
					BorderComponentY1.AddZeroed(ComponentSizeX);
					BorderComponentY2.AddZeroed(ComponentSizeX);
					bHasMissingValue = true;
				}

				// Search for neighbor component for interpolation
				bool bShouldSearchX = (BorderComponent[1] && BorderComponent[1]->GetSectionBase().X / ComponentSizeQuads <= ComponentIndexX);
				bool bShouldSearchY = (BorderComponentY2[ComponentIndexXX] && BorderComponentY2[ComponentIndexXX]->GetSectionBase().Y / ComponentSizeQuads <= ComponentIndexY);
				// Search for left-closest component
				if ( bShouldSearchX || (!NoBorderX1 && !BorderComponent[0]))
				{
					NoBorderX1 = true;
					for (int32 X = ComponentIndexX-1; X >= ComponentIndexX1; X--)
					{
						BorderComponent[0] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X,ComponentIndexY));
						if (BorderComponent[0])
						{
							NoBorderX1 = false;
							if (LayerInfo != NULL)
							{
								for( int32 LayerIdx=0;LayerIdx<BorderComponent[0]->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									if( BorderComponent[0]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
									{
										NeighborWeightmapTexture[0] = BorderComponent[0]->WeightmapTextures[BorderComponent[0]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
										NeighborTexDataInfo[0] = GetTextureDataInfo(NeighborWeightmapTexture[0]);
										NeighborWeightmapTextureData[0] = (uint8*)NeighborTexDataInfo[0]->GetMipData(0);
										NeighborWeightmapChannelOffset[0] = ChannelOffsets[BorderComponent[0]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
										break;
									}
								}
							}
							break;
						}
					}
				}
				// Search for right-closest component
				if ( bShouldSearchX || (!NoBorderX2 && !BorderComponent[1]))
				{
					NoBorderX2 = true;
					for (int32 X = ComponentIndexX+1; X <= ComponentIndexX2; X++)
					{
						BorderComponent[1] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X,ComponentIndexY));
						if (BorderComponent[1])
						{
							NoBorderX2 = false;
							if (LayerInfo != NULL)
							{
								for( int32 LayerIdx=0;LayerIdx<BorderComponent[1]->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									if( BorderComponent[1]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
									{
										NeighborWeightmapTexture[1] = BorderComponent[1]->WeightmapTextures[BorderComponent[1]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
										NeighborTexDataInfo[1] = GetTextureDataInfo(NeighborWeightmapTexture[1]);
										NeighborWeightmapTextureData[1] = (uint8*)NeighborTexDataInfo[1]->GetMipData(0);
										NeighborWeightmapChannelOffset[1] = ChannelOffsets[BorderComponent[1]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
										break;
									}
								}
							}
						}
					}
				}
				// Search for up-closest component
				if ( bShouldSearchY || (!NoBorderY1[ComponentIndexXX] && !BorderComponentY1[ComponentIndexXX]))
				{
					NoBorderY1[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY-1; Y >= ComponentIndexY1; Y--)
					{
						BorderComponentY1[ComponentIndexXX] = BorderComponent[2] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,Y));
						if (BorderComponent[2])
						{
							NoBorderY1[ComponentIndexXX] = false;
							if (LayerInfo != NULL)
							{
								for( int32 LayerIdx=0;LayerIdx<BorderComponent[2]->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									if( BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
									{
										NeighborWeightmapTexture[2] = BorderComponent[2]->WeightmapTextures[BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
										NeighborTexDataInfo[2] = GetTextureDataInfo(NeighborWeightmapTexture[2]);
										NeighborWeightmapTextureData[2] = (uint8*)NeighborTexDataInfo[2]->GetMipData(0);
										NeighborWeightmapChannelOffset[2] = ChannelOffsets[BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
										break;
									}
								}
							}
						}
					}
				}
				else
				{
					BorderComponent[2] = BorderComponentY1[ComponentIndexXX];
					if (BorderComponent[2])
					{
						if (LayerInfo != NULL)
						{
							for( int32 LayerIdx=0;LayerIdx<BorderComponent[2]->WeightmapLayerAllocations.Num();LayerIdx++ )
							{
								if( BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
								{
									NeighborWeightmapTexture[2] = BorderComponent[2]->WeightmapTextures[BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
									NeighborTexDataInfo[2] = GetTextureDataInfo(NeighborWeightmapTexture[2]);
									NeighborWeightmapTextureData[2] = (uint8*)NeighborTexDataInfo[2]->GetMipData(0);
									NeighborWeightmapChannelOffset[2] = ChannelOffsets[BorderComponent[2]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
									break;
								}
							}
						}
					}
				}
				// Search for bottom-closest component
				if ( bShouldSearchY || (!NoBorderY2[ComponentIndexXX] && !BorderComponentY2[ComponentIndexXX]))
				{
					NoBorderY2[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY+1; Y <= ComponentIndexY2; Y++)
					{
						BorderComponentY2[ComponentIndexXX] = BorderComponent[3] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,Y));
						if (BorderComponent[3])
						{
							NoBorderY2[ComponentIndexXX] = false;
							if (LayerInfo != NULL)
							{
								for( int32 LayerIdx=0;LayerIdx<BorderComponent[3]->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									if( BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
									{
										NeighborWeightmapTexture[3] = BorderComponent[3]->WeightmapTextures[BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
										NeighborTexDataInfo[3] = GetTextureDataInfo(NeighborWeightmapTexture[3]);
										NeighborWeightmapTextureData[3] = (uint8*)NeighborTexDataInfo[3]->GetMipData(0);
										NeighborWeightmapChannelOffset[3] = ChannelOffsets[BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
										break;
									}
								}
							}
							break;
						}
					}
				}
				else
				{
					BorderComponent[3] = BorderComponentY2[ComponentIndexXX];
					if (BorderComponent[3])
					{
						if (LayerInfo != NULL)
						{
							for( int32 LayerIdx=0;LayerIdx<BorderComponent[3]->WeightmapLayerAllocations.Num();LayerIdx++ )
							{
								if( BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].LayerInfo == LayerInfo )
								{
									NeighborWeightmapTexture[3] = BorderComponent[3]->WeightmapTextures[BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex];
									NeighborTexDataInfo[3] = GetTextureDataInfo(NeighborWeightmapTexture[3]);
									NeighborWeightmapTextureData[3] = (uint8*)NeighborTexDataInfo[3]->GetMipData(0);
									NeighborWeightmapChannelOffset[3] = ChannelOffsets[BorderComponent[3]->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];
									break;
								}
							}
						}
					}
				}

				CornerComponent[0] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX-1),(ComponentIndexY-1))) : NULL;
				CornerComponent[1] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX+1),(ComponentIndexY-1))) : NULL;
				CornerComponent[2] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX-1),(ComponentIndexY+1))) : NULL;
				CornerComponent[3] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX+1),(ComponentIndexY+1))) : NULL;

				if (CornerComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetWeightMapData(CornerComponent[0], LayerInfo, EdgeCoord, EdgeCoord);
				}
				else if ((ExistLeft || ExistUp) && X1 <= ComponentIndexX*ComponentSizeQuads && Y1 <= ComponentIndexY*ComponentSizeQuads  )
				{
					CornerSet |= 1;
					CornerValues[0] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads);
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetWeightMapData(BorderComponent[0], LayerInfo, EdgeCoord, 0, NeighborWeightmapChannelOffset[0], NeighborWeightmapTexture[0], NeighborWeightmapTextureData[0]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1;
					CornerValues[0] = GetWeightMapData(BorderComponent[2], LayerInfo, 0, EdgeCoord, NeighborWeightmapChannelOffset[2], NeighborWeightmapTexture[2], NeighborWeightmapTextureData[2]);
				}

				if (CornerComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetWeightMapData(CornerComponent[1], LayerInfo, 0, EdgeCoord);
				}
				else if (ExistUp && X2 >= (ComponentIndexX+1)*ComponentSizeQuads)
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = StoreData.Load( (ComponentIndexX+1)*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads);
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetWeightMapData(BorderComponent[1], LayerInfo, 0, 0, NeighborWeightmapChannelOffset[1], NeighborWeightmapTexture[1], NeighborWeightmapTextureData[1]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetWeightMapData(BorderComponent[2], LayerInfo, EdgeCoord, EdgeCoord, NeighborWeightmapChannelOffset[2], NeighborWeightmapTexture[2], NeighborWeightmapTextureData[2]);
				}

				if (CornerComponent[2])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetWeightMapData(CornerComponent[2], LayerInfo, EdgeCoord, 0);
				}
				else if (ExistLeft && Y2 >= (ComponentIndexY+1)*ComponentSizeQuads) // Use data already stored for 0, 2
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, (ComponentIndexY+1)*ComponentSizeQuads);
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetWeightMapData(BorderComponent[0], LayerInfo, EdgeCoord, EdgeCoord, NeighborWeightmapChannelOffset[0], NeighborWeightmapTexture[0], NeighborWeightmapTextureData[0]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetWeightMapData(BorderComponent[3], LayerInfo, 0, 0, NeighborWeightmapChannelOffset[3], NeighborWeightmapTexture[3], NeighborWeightmapTextureData[3]);
				}

				if (CornerComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetWeightMapData(CornerComponent[3], LayerInfo, 0, 0);
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetWeightMapData(BorderComponent[1], LayerInfo, 0, EdgeCoord, NeighborWeightmapChannelOffset[1], NeighborWeightmapTexture[1], NeighborWeightmapTextureData[1]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetWeightMapData(BorderComponent[3], LayerInfo, EdgeCoord, 0, NeighborWeightmapChannelOffset[3], NeighborWeightmapTexture[3], NeighborWeightmapTextureData[3]);
				}

				FillCornerValues(CornerSet, CornerValues);
				ComponentDataExist[ComponentIndexXY] = ExistLeft || ExistUp || (BorderComponent[0] || BorderComponent[1] || BorderComponent[2] || BorderComponent[3]) || CornerSet;
			}

			if (!ComponentDataExist[ComponentIndexXY])
			{
				continue;
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							if (LayerInfo != NULL)
							{
								// Find the input data corresponding to this vertex
								uint8 Weight;
								if( WeightmapTexture )
								{
									// Find the texture data corresponding to this vertex
									Weight = GetWeightMapData(Component, LayerInfo, (SubsectionSizeQuads+1) * SubIndexX + SubX, (SubsectionSizeQuads+1) * SubIndexY + SubY, WeightmapChannelOffset, WeightmapTexture, WeightmapTextureData );
									StoreData.Store(LandscapeX, LandscapeY, Weight);
								}
								else
								{
									// Find the texture data corresponding to this vertex
									uint8 Value[4] = {0, 0, 0, 0};
									int32 Dist[4] = {INT_MAX, INT_MAX, INT_MAX, INT_MAX};
									float ValueX = 0.0f, ValueY = 0.0f;
									bool Exist[4] = {false, false, false, false};

									// Use data already stored for 0, 2
									if (ExistLeft && SubX == 0)
									{
										Value[0] = StoreData.Load( ComponentIndexX*ComponentSizeQuads, LandscapeY);
										Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										Exist[0] = true;
									}
									else if (BorderComponent[0] && NeighborWeightmapTexture[0])
									{
										Value[0] = GetWeightMapData(BorderComponent[0], LayerInfo, EdgeCoord, (SubsectionSizeQuads+1) * SubIndexY + SubY, NeighborWeightmapChannelOffset[0], NeighborWeightmapTexture[0], NeighborWeightmapTextureData[0]);
										Dist[0] = LandscapeX - (BorderComponent[0]->GetSectionBase().X + ComponentSizeQuads);
										Exist[0] = true;
									}
									else 
									{
										if ((CornerSet & 1) && (CornerSet & 1 << 2))
										{
											int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
											int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
											Value[0] = (float)(Dist2 * CornerValues[0] + Dist1 * CornerValues[2]) / (Dist1 + Dist2);
											Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
											Exist[0] = true;
										}
									}

									if (BorderComponent[1] && NeighborWeightmapTexture[1])
									{
										Value[1] = GetWeightMapData(BorderComponent[1], LayerInfo, 0, (SubsectionSizeQuads+1) * SubIndexY + SubY, NeighborWeightmapChannelOffset[1], NeighborWeightmapTexture[1], NeighborWeightmapTextureData[1]);
										Dist[1] = (BorderComponent[1]->GetSectionBase().X) - LandscapeX;
										Exist[1] = true;
									}
									else
									{
										if ((CornerSet & 1 << 1) && (CornerSet & 1 << 3))
										{
											int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
											int32 Dist2 = ((ComponentIndexY+1)*ComponentSizeQuads) - LandscapeY;
											Value[1] = (float)(Dist2 * CornerValues[1] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
											Dist[1] = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
											Exist[1] = true;
										}
									}

									if (ExistUp && SubY == 0)
									{
										Value[2] = StoreData.Load( LandscapeX, ComponentIndexY*ComponentSizeQuads);
										Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										Exist[2] = true;
									}
									else if (BorderComponent[2] && NeighborWeightmapTexture[2])
									{
										Value[2] = GetWeightMapData(BorderComponent[2], LayerInfo, (SubsectionSizeQuads+1) * SubIndexX + SubX, EdgeCoord, NeighborWeightmapChannelOffset[2], NeighborWeightmapTexture[2], NeighborWeightmapTextureData[2]);
										Dist[2] = LandscapeY - (BorderComponent[2]->GetSectionBase().Y + ComponentSizeQuads);
										Exist[2] = true;
									}
									else
									{
										if ((CornerSet & 1) && (CornerSet & 1 << 1))
										{
											int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
											int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
											Value[2] = (float)(Dist2 * CornerValues[0] + Dist1 * CornerValues[1]) / (Dist1 + Dist2);
											Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
											Exist[2] = true;
										}
									}

									if (BorderComponent[3] && NeighborWeightmapTexture[3])
									{
										Value[3] = GetWeightMapData(BorderComponent[3], LayerInfo, (SubsectionSizeQuads+1) * SubIndexX + SubX, 0, NeighborWeightmapChannelOffset[3], NeighborWeightmapTexture[3], NeighborWeightmapTextureData[3]);
										Dist[3] = (BorderComponent[3]->GetSectionBase().Y) - LandscapeY;
										Exist[3] = true;
									}
									else
									{
										if ((CornerSet & 1 << 2) && (CornerSet & 1 << 3))
										{
											int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
											int32 Dist2 = (ComponentIndexX+1)*ComponentSizeQuads - LandscapeX;
											Value[3] = (float)(Dist2 * CornerValues[2] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
											Dist[3] = (ComponentIndexY+1)*ComponentSizeQuads - LandscapeY;
											Exist[3] = true;
										}
									}

									CalcInterpValue<uint8>(Dist, Exist, Value, ValueX, ValueY);

									uint8 FinalValue = 0; // Default Value
									if ( (Exist[0] || Exist[1]) && (Exist[2] || Exist[3]) )
									{
										FinalValue = CalcValueFromValueXY<uint8>(Dist, ValueX, ValueY, CornerSet, CornerValues);
									}
									else if ( (Exist[0] || Exist[1]) )
									{
										FinalValue = ValueX;
									}
									else if ( (Exist[2] || Exist[3]) )
									{
										FinalValue = ValueY;
									}

									Weight = FinalValue;
								}

								StoreData.Store(LandscapeX, LandscapeY, Weight);
							}
							else // Whole weight map case... no interpolation now...
							{
								StoreData.PreInit(LandscapeInfo->Layers.Num());
								for( int32 LayerIdx=0;LayerIdx<Component->WeightmapLayerAllocations.Num();LayerIdx++ )
								{
									int32 Idx = Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureIndex;
									UTexture2D* ComponentWeightmapTexture = Component->WeightmapTextures[Idx];
									uint8* ComponentWeightmapTextureData = (uint8*)TexDataInfos[Idx]->GetMipData(0);
									uint8 ComponentWeightmapChannelOffset = ChannelOffsets[Component->WeightmapLayerAllocations[LayerIdx].WeightmapTextureChannel];

									// Find the texture data corresponding to this vertex
									int32 SizeU = ComponentWeightmapTexture->Source.GetSizeX();
									int32 SizeV = ComponentWeightmapTexture->Source.GetSizeY();
									int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
									int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

									int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
									int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;

									uint8 Weight = ComponentWeightmapTextureData[ 4 * (TexX + TexY * SizeU) + ComponentWeightmapChannelOffset ];

									// Find index in LayerInfos
									{
										int32 LayerInfoIdx = LandscapeInfo->GetLayerInfoIndex(Component->WeightmapLayerAllocations[LayerIdx].LayerInfo);
										if (LayerInfoIdx != INDEX_NONE)
										{
											StoreData.Store(LandscapeX, LandscapeY, Weight, LayerInfoIdx);
										}
									}
								}
							}
						}
					}
				}
			}
		}
	}

	if (bHasMissingValue)
	{
		CalcMissingValues<uint8, TStoreData, float>( X1, X2, Y1, Y2,
			ComponentIndexX1, ComponentIndexX2, ComponentIndexY1, ComponentIndexY2, 
			ComponentSizeX, ComponentSizeY, CornerValues,
			NoBorderY1, NoBorderY2, ComponentDataExist, StoreData );
		// Update valid region
		ValidX1 = FMath::Max<int32>(X1, ValidX1);
		ValidX2 = FMath::Min<int32>(X2, ValidX2);
		ValidY1 = FMath::Max<int32>(Y1, ValidY1);
		ValidY2 = FMath::Min<int32>(Y2, ValidY2);
	}
	else
	{
		ValidX1 = X1;
		ValidX2 = X2;
		ValidY1 = Y1;
		ValidY2 = Y2;
	}
}

void FLandscapeEditDataInterface::GetWeightData(ULandscapeLayerInfoObject* LayerInfo, int32& X1, int32& Y1, int32& X2, int32& Y2, uint8* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<uint8> ArrayStoreData(X1, Y1, Data, Stride);
	GetWeightDataTempl(LayerInfo, X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetWeightDataFast(ULandscapeLayerInfoObject* LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, uint8* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<uint8> ArrayStoreData(X1, Y1, Data, Stride);
	GetWeightDataTemplFast(LayerInfo, X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetWeightData(ULandscapeLayerInfoObject* LayerInfo, int32& X1, int32& Y1, int32& X2, int32& Y2, TMap<FIntPoint, uint8>& SparseData)
{
	TSparseStoreData<uint8> SparseStoreData(SparseData);
	GetWeightDataTempl(LayerInfo, X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetWeightDataFast(ULandscapeLayerInfoObject* LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, uint8>& SparseData)
{
	TSparseStoreData<uint8> SparseStoreData(SparseData);
	GetWeightDataTemplFast(LayerInfo, X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetWeightDataFast(ULandscapeLayerInfoObject* LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TArray<uint8>* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<TArray<uint8>> ArrayStoreData(X1, Y1, Data, Stride);
	GetWeightDataTemplFast(LayerInfo, X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetWeightDataFast(ULandscapeLayerInfoObject* LayerInfo, const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, TArray<uint8>>& SparseData)
{
	TSparseStoreData<TArray<uint8>> SparseStoreData(SparseData);
	GetWeightDataTemplFast(LayerInfo, X1, Y1, X2, Y2, SparseStoreData);
}

FLandscapeTextureDataInfo* FLandscapeTextureDataInterface::GetTextureDataInfo(UTexture2D* Texture)
{
	FLandscapeTextureDataInfo* Result = TextureDataMap.FindRef(Texture);
	if( !Result )
	{
		Result = TextureDataMap.Add(Texture, new FLandscapeTextureDataInfo(Texture));
	}
	return Result;
}

void FLandscapeTextureDataInterface::CopyTextureChannel(UTexture2D* Dest, int32 DestChannel, UTexture2D* Src, int32 SrcChannel)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Dest);
	FLandscapeTextureDataInfo* SrcDataInfo = GetTextureDataInfo(Src);
	int32 MipSize = Dest->Source.GetSizeX();
	check(Dest->Source.GetSizeX() == Dest->Source.GetSizeY() && Src->Source.GetSizeX() == Dest->Source.GetSizeX());

	for( int32 MipIdx=0;MipIdx<DestDataInfo->NumMips();MipIdx++ )
	{
		uint8* DestTextureData = (uint8*)DestDataInfo->GetMipData(MipIdx) + ChannelOffsets[DestChannel];
		uint8* SrcTextureData = (uint8*)SrcDataInfo->GetMipData(MipIdx) + ChannelOffsets[SrcChannel];

		for( int32 i=0;i<FMath::Square(MipSize);i++ )
		{
			DestTextureData[i*4] = SrcTextureData[i*4];
		}

		DestDataInfo->AddMipUpdateRegion(MipIdx, 0, 0, MipSize-1, MipSize-1);
		MipSize >>= 1;
	}
}

void FLandscapeTextureDataInterface::CopyTextureFromHeightmap(UTexture2D* Dest, int32 DestChannel, ULandscapeComponent* Comp, int32 SrcChannel)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Dest);
	int32 MipSize = Dest->Source.GetSizeX();
	check(Dest->Source.GetSizeX() == Dest->Source.GetSizeY());

	for( int32 MipIdx=0;MipIdx<DestDataInfo->NumMips();MipIdx++ )
	{
		FLandscapeComponentDataInterface DataInterface(Comp, MipIdx);
		TArray<FColor> Heightmap;
		DataInterface.GetHeightmapTextureData(Heightmap);

		uint8* DestTextureData = (uint8*)DestDataInfo->GetMipData(MipIdx) + ChannelOffsets[DestChannel];
		uint8* SrcTextureData = (uint8*)Heightmap.GetData() + ChannelOffsets[SrcChannel];

		for( int32 i=0;i<FMath::Square(MipSize);i++ )
		{
			DestTextureData[i*4] = SrcTextureData[i*4];
		}

		DestDataInfo->AddMipUpdateRegion(MipIdx, 0, 0, MipSize-1, MipSize-1);
		MipSize >>= 1;
	}
}

void FLandscapeTextureDataInterface::CopyTextureFromWeightmap(UTexture2D* Dest, int32 DestChannel, ULandscapeComponent* Comp, ULandscapeLayerInfoObject* LayerInfo)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Dest);
	int32 MipSize = Dest->Source.GetSizeX();
	check(Dest->Source.GetSizeX() == Dest->Source.GetSizeY());

	for (int32 MipIdx = 0; MipIdx < DestDataInfo->NumMips(); MipIdx++)
	{
		FLandscapeComponentDataInterface DataInterface(Comp, MipIdx);
		TArray<uint8> WeightData;
		DataInterface.GetWeightmapTextureData(LayerInfo, WeightData);

		uint8* DestTextureData = (uint8*)DestDataInfo->GetMipData(MipIdx) + ChannelOffsets[DestChannel];

		for (int32 i = 0; i < FMath::Square(MipSize); i++)
		{
			DestTextureData[i * 4] = WeightData[i];
		}

		DestDataInfo->AddMipUpdateRegion(MipIdx, 0, 0, MipSize - 1, MipSize - 1);
		MipSize >>= 1;
	}
}

void FLandscapeTextureDataInterface::ZeroTextureChannel(UTexture2D* Dest, int32 DestChannel)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Dest);
	int32 MipSize = Dest->Source.GetSizeX();
	check(Dest->Source.GetSizeX() == Dest->Source.GetSizeY());

	for( int32 MipIdx=0;MipIdx<DestDataInfo->NumMips();MipIdx++ )
	{
		uint8* DestTextureData = (uint8*)DestDataInfo->GetMipData(MipIdx) + ChannelOffsets[DestChannel];

		for( int32 i=0;i<FMath::Square(MipSize);i++ )
		{
			DestTextureData[i*4] = 0;
		}

		DestDataInfo->AddMipUpdateRegion(MipIdx, 0, 0, MipSize-1, MipSize-1);
		MipSize >>= 1;
	}
}

template<typename TData>
void FLandscapeTextureDataInterface::SetTextureValueTempl(UTexture2D* Dest, TData Value)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Dest);
	int32 MipSize = Dest->Source.GetSizeX();
	check(Dest->Source.GetSizeX() == Dest->Source.GetSizeY());

	for( int32 MipIdx=0;MipIdx<DestDataInfo->NumMips();MipIdx++ )
	{
		TData* DestTextureData = (TData*)DestDataInfo->GetMipData(MipIdx);

		for( int32 i=0;i<FMath::Square(MipSize);i++ )
		{
			DestTextureData[i] = Value;
		}

		DestDataInfo->AddMipUpdateRegion(MipIdx, 0, 0, MipSize-1, MipSize-1);
		MipSize >>= 1;
	}
}

void FLandscapeTextureDataInterface::ZeroTexture(UTexture2D* Dest)
{
	SetTextureValueTempl<uint8>(Dest, 0);
}

void FLandscapeTextureDataInterface::SetTextureValue(UTexture2D* Dest, FColor Value)
{
	SetTextureValueTempl<FColor>(Dest, Value);
}

template<typename TData>
bool FLandscapeTextureDataInterface::EqualTextureValueTempl(UTexture2D* Src, TData Value)
{
	FLandscapeTextureDataInfo* DestDataInfo = GetTextureDataInfo(Src);
	TData* DestTextureData = (TData*)DestDataInfo->GetMipData(0);
	int32 Size = Src->Source.GetSizeX() * Src->Source.GetSizeY();

	for( int32 i = 0 ;i < Size; ++i )
	{
		if (DestTextureData[i] != Value)
		{
			return false;
		}
	}

	return true;
}

bool FLandscapeTextureDataInterface::EqualTextureValue(UTexture2D* Src, FColor Value)
{
	return EqualTextureValueTempl<FColor>(Src, Value);
}


template<typename TStoreData>
void FLandscapeEditDataInterface::GetSelectDataTempl(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TStoreData& StoreData)
{
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{		
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			uint8* SelectTextureData = NULL;
			if( Component && Component->EditToolRenderData.DataTexture )
			{
				TexDataInfo = GetTextureDataInfo(Component->EditToolRenderData.DataTexture);
				SelectTextureData = (uint8*)TexDataInfo->GetMipData(0);
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							// Find the input data corresponding to this vertex
							if( Component && SelectTextureData )
							{
								// Find the texture data corresponding to this vertex
								int32 SizeU = Component->EditToolRenderData.DataTexture->Source.GetSizeX();
								int32 SizeV = Component->EditToolRenderData.DataTexture->Source.GetSizeY();
								int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
								int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

								int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
								int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
								uint8& TexData = SelectTextureData[ TexX + TexY * SizeU ];

								StoreData.Store(LandscapeX, LandscapeY, TexData);
							}
							else
							{
								StoreData.Store(LandscapeX, LandscapeY, 0);
							}

						}
					}
				}
			}
		}
	}
}

void FLandscapeEditDataInterface::GetSelectData(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, uint8>& SparseData)
{
	TSparseStoreData<uint8> SparseStoreData(SparseData);
	GetSelectDataTempl(X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetSelectData(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, uint8* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<uint8> ArrayStoreData(X1, Y1, Data, Stride);
	GetSelectDataTempl(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::SetSelectData(int32 X1, int32 Y1, int32 X2, int32 Y2, const uint8* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}

	check(ComponentSizeQuads > 0);
	// Find component range for this block of data
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{	
			FIntPoint ComponentKey(ComponentIndexX,ComponentIndexY);
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(ComponentKey);

			UTexture2D* DataTexture = NULL;
			// if NULL, it was painted away
			if( Component==NULL)
			{
				continue;
			}
			else if (Component->EditToolRenderData.DataTexture == NULL)
			{
				//FlushRenderingCommands();
				// Construct Texture...
				int32 WeightmapSize = (Component->SubsectionSizeQuads+1) * Component->NumSubsections;
				DataTexture = Component->GetLandscapeProxy()->CreateLandscapeTexture(WeightmapSize, WeightmapSize, TEXTUREGROUP_Terrain_Weightmap, TSF_G8);
				// Alloc dummy mips
				ULandscapeComponent::CreateEmptyTextureMips(DataTexture, true);
				DataTexture->PostEditChange();

				//FlushRenderingCommands();
				ZeroTexture(DataTexture);
				FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(DataTexture);
				int32 NumMips = DataTexture->Source.GetNumMips();
				TArray<uint8*> TextureMipData;
				TextureMipData.AddUninitialized(NumMips);
				for( int32 MipIdx=0;MipIdx<NumMips;MipIdx++ )
				{
					TextureMipData[MipIdx] = (uint8*)TexDataInfo->GetMipData(MipIdx);
				}
				ULandscapeComponent::UpdateDataMips(ComponentNumSubsections, SubsectionSizeQuads, DataTexture, TextureMipData, 0, 0, MAX_int32, MAX_int32, TexDataInfo);
				
				Component->EditToolRenderData.DataTexture = DataTexture;
				Component->UpdateEditToolRenderData();
			}
			else
			{
				DataTexture = Component->EditToolRenderData.DataTexture;
			}

			FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(DataTexture);
			uint8* SelectTextureData = (uint8*)TexDataInfo->GetMipData(0);

			// Find the texture data corresponding to this vertex
			int32 SizeU = DataTexture->Source.GetSizeX();
			int32 SizeV = DataTexture->Source.GetSizeY();
			int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
			int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;
							checkSlow( LandscapeX >= X1 && LandscapeX <= X2 );
							checkSlow( LandscapeY >= Y1 && LandscapeY <= Y2 );

							// Find the input data corresponding to this vertex
							int32 DataIndex = (LandscapeX-X1) + Stride * (LandscapeY-Y1);
							const uint8& Value = Data[DataIndex];

							int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
							int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
							uint8& TexData = SelectTextureData[ TexX + TexY * SizeU ];

							TexData = Value;
						}
					}

					// Record the areas of the texture we need to re-upload
					int32 TexX1 = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX1;
					int32 TexY1 = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY1;
					int32 TexX2 = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX2;
					int32 TexY2 = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY2;
					TexDataInfo->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);
				}
			}
			// Update mipmaps
			int32 NumMips = DataTexture->Source.GetNumMips();
			TArray<uint8*> TextureMipData;
			TextureMipData.AddUninitialized(NumMips);
			for( int32 MipIdx=0;MipIdx<NumMips;MipIdx++ )
			{
				TextureMipData[MipIdx] = (uint8*)TexDataInfo->GetMipData(MipIdx);
			}
			ULandscapeComponent::UpdateDataMips(ComponentNumSubsections, SubsectionSizeQuads, DataTexture, TextureMipData, ComponentX1, ComponentY1, ComponentX2, ComponentY2, TexDataInfo);
		}
	}
}

template<typename T>
void FLandscapeEditDataInterface::SetXYOffsetDataTempl(int32 X1, int32 Y1, int32 X2, int32 Y2, const T* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}

	check(ComponentSizeQuads > 0);
	// Find component range for this block of data
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	const FColor DefaultValue(128, 0, 128, 0);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{	
			FIntPoint ComponentKey(ComponentIndexX,ComponentIndexY);
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(ComponentKey);

			UTexture2D* XYOffsetTexture = NULL;
			if( Component==NULL)
			{
				continue;
			}
			else
			{
				if (Component->XYOffsetmapTexture == NULL)
				{
					Component->Modify();
					//FlushRenderingCommands();
					// Construct Texture...
					int32 WeightmapSize = (Component->SubsectionSizeQuads+1) * Component->NumSubsections;
					XYOffsetTexture = Component->GetLandscapeProxy()->CreateLandscapeTexture(WeightmapSize, WeightmapSize, TEXTUREGROUP_Terrain_Weightmap, TSF_BGRA8);
					// Alloc dummy mips
					ULandscapeComponent::CreateEmptyTextureMips(XYOffsetTexture, true);
					XYOffsetTexture->PostEditChange();

					//FlushRenderingCommands();
					SetTextureValue(XYOffsetTexture, DefaultValue);
					FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(XYOffsetTexture);
					int32 NumMips = XYOffsetTexture->Source.GetNumMips();
					TArray<FColor*> TextureMipData;
					TextureMipData.AddUninitialized(NumMips);
					for( int32 MipIdx=0;MipIdx<NumMips;MipIdx++ )
					{
						TextureMipData[MipIdx] = (FColor*)TexDataInfo->GetMipData(MipIdx);
					}
					ULandscapeComponent::UpdateWeightmapMips(ComponentNumSubsections, SubsectionSizeQuads, XYOffsetTexture, TextureMipData, 0, 0, MAX_int32, MAX_int32, TexDataInfo);

					Component->XYOffsetmapTexture = XYOffsetTexture;
					FComponentReregisterContext ReregisterContext(Component);
				}
				else
				{
					XYOffsetTexture = Component->XYOffsetmapTexture;
				}
			}

			FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(XYOffsetTexture);
			FColor* XYOffsetTextureData = (FColor*)TexDataInfo->GetMipData(0);

			// Find the texture data corresponding to this vertex
			int32 SizeU = XYOffsetTexture->Source.GetSizeX();
			int32 SizeV = XYOffsetTexture->Source.GetSizeY();
			int32 WeightmapOffsetX = Component->WeightmapScaleBias.Z * (float)SizeU;
			int32 WeightmapOffsetY = Component->WeightmapScaleBias.W * (float)SizeV;

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;
							checkSlow( LandscapeX >= X1 && LandscapeX <= X2 );
							checkSlow( LandscapeY >= Y1 && LandscapeY <= Y2 );

							// Find the input data corresponding to this vertex
							int32 DataIndex = (LandscapeX-X1) + Stride * (LandscapeY-Y1);
							const T& Value = Data[DataIndex];

							int32 TexX = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX;
							int32 TexY = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY;
							FColor& TexData = XYOffsetTextureData[ TexX + TexY * SizeU ];

							uint16 XOffset = FMath::Clamp<uint16>(Value.X * LANDSCAPE_INV_XYOFFSET_SCALE + 32768.0f, 0, 65535);
							uint16 YOffset = FMath::Clamp<uint16>(Value.Y * LANDSCAPE_INV_XYOFFSET_SCALE + 32768.0f, 0, 65535);

							TexData.R = XOffset >> 8;
							TexData.G = XOffset & 255;
							TexData.B = YOffset >> 8;
							TexData.A = YOffset & 255;
						}
					}

					// Record the areas of the texture we need to re-upload
					int32 TexX1 = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX1;
					int32 TexY1 = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY1;
					int32 TexX2 = WeightmapOffsetX + (SubsectionSizeQuads+1) * SubIndexX + SubX2;
					int32 TexY2 = WeightmapOffsetY + (SubsectionSizeQuads+1) * SubIndexY + SubY2;
					TexDataInfo->AddMipUpdateRegion(0,TexX1,TexY1,TexX2,TexY2);
				}
			}

			// Update mipmaps
			int32 NumMips = XYOffsetTexture->Source.GetNumMips();
			TArray<FColor*> TextureMipData;
			TextureMipData.AddUninitialized(NumMips);
			for( int32 MipIdx=0;MipIdx<NumMips;MipIdx++ )
			{
				TextureMipData[MipIdx] = (FColor*)TexDataInfo->GetMipData(MipIdx);
			}
			ULandscapeComponent::UpdateWeightmapMips(ComponentNumSubsections, SubsectionSizeQuads, XYOffsetTexture, TextureMipData, ComponentX1, ComponentY1, ComponentX2, ComponentY2, TexDataInfo);
		}
	}
}

void FLandscapeEditDataInterface::SetXYOffsetData(int32 X1, int32 Y1, int32 X2, int32 Y2, const FVector2D* Data, int32 Stride)
{
	SetXYOffsetDataTempl<FVector2D>(X1, Y1, X2, Y2, Data, Stride);
}

void FLandscapeEditDataInterface::SetXYOffsetData(int32 X1, int32 Y1, int32 X2, int32 Y2, const FVector* Data, int32 Stride)
{
	SetXYOffsetDataTempl<FVector>(X1, Y1, X2, Y2, Data, Stride);
}

FVector2D FLandscapeEditDataInterface::GetXYOffsetmapData(const ULandscapeComponent* Component, int32 TexU, int32 TexV, FColor* TextureData/* = NULL*/)
{
	check(Component);
	if (!TextureData && Component->XYOffsetmapTexture)
	{
		FLandscapeTextureDataInfo* TexDataInfo = GetTextureDataInfo(Component->XYOffsetmapTexture);
		TextureData = (FColor*)TexDataInfo->GetMipData(0);	
	}

	if (TextureData)
	{
		int32 SizeU = Component->NumSubsections * (Component->SubsectionSizeQuads + 1);
		int32 SizeV = Component->NumSubsections * (Component->SubsectionSizeQuads + 1);

		int32 TexX = TexU;
		int32 TexY = TexV;
		FColor& TexData = TextureData[ TexX + TexY * SizeU ];
		return FVector2D(((TexData.R * 256.0 + TexData.G) - 32768.0) * LANDSCAPE_XYOFFSET_SCALE, ((TexData.B * 256.0 + TexData.A) - 32768.0) * LANDSCAPE_XYOFFSET_SCALE );
	}
	return FVector2D::ZeroVector;
}

// XYOffset Interpolation version
template<typename TStoreData>
void FLandscapeEditDataInterface::GetXYOffsetDataTempl(int32& ValidX1, int32& ValidY1, int32& ValidX2, int32& ValidY2, TStoreData& StoreData)
{
	// Copy variables
	int32 X1 = ValidX1, X2 = ValidX2, Y1 = ValidY1, Y2 = ValidY2;
	ValidX1 = INT_MAX; ValidX2 = INT_MIN; ValidY1 = INT_MAX; ValidY2 = INT_MIN;

	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	int32 ComponentSizeX = ComponentIndexX2 - ComponentIndexX1 + 1;
	int32 ComponentSizeY = ComponentIndexY2 - ComponentIndexY1 + 1;

	// Neighbor Components
	ULandscapeComponent* BorderComponent[4] = { 0, 0, 0, 0 };
	ULandscapeComponent* CornerComponent[4] = { 0, 0, 0, 0 };
	bool NoBorderX1 = false, NoBorderX2 = false;
	TArray<bool> NoBorderY1, NoBorderY2, ComponentDataExist;
	TArray<ULandscapeComponent*> BorderComponentY1, BorderComponentY2;
	ComponentDataExist.Empty(ComponentSizeX*ComponentSizeY);
	ComponentDataExist.AddZeroed(ComponentSizeX*ComponentSizeY);
	bool bHasMissingValue = false;

	FLandscapeTextureDataInfo* NeighborTexDataInfo[4] = { 0, 0, 0, 0 };
	FColor* NeighborXYOffsetmapTextureData[4] = { 0, 0, 0, 0 };
	FVector2D CornerValues[4] = { FVector2D::ZeroVector, FVector2D::ZeroVector, FVector2D::ZeroVector, FVector2D::ZeroVector };

	int32 EdgeCoord = (SubsectionSizeQuads + 1) * ComponentNumSubsections - 1; //ComponentSizeQuads;

	TArray<FColor> EmptyXYOffset;
	int32 XYOffsetSize = (LandscapeInfo->SubsectionSizeQuads + 1) * LandscapeInfo->ComponentNumSubsections;
	XYOffsetSize = XYOffsetSize * XYOffsetSize;
	EmptyXYOffset.Empty(XYOffsetSize);
	for (int32 i = 0; i < XYOffsetSize; ++i)
	{
		EmptyXYOffset.Add(FColor(128, 0, 128, 0));
	}

	// initial loop....
	for (int32 ComponentIndexY = ComponentIndexY1; ComponentIndexY <= ComponentIndexY2; ComponentIndexY++)
	{
		NoBorderX1 = false;
		NoBorderX2 = false;
		BorderComponent[0] = BorderComponent[1] = NULL;
		for (int32 ComponentIndexX = ComponentIndexX1; ComponentIndexX <= ComponentIndexX2; ComponentIndexX++)
		{
			BorderComponent[2] = BorderComponent[3] = NULL;
			int32 ComponentIndexXY = ComponentSizeX*(ComponentIndexY - ComponentIndexY1) + ComponentIndexX - ComponentIndexX1;
			int32 ComponentIndexXX = ComponentIndexX - ComponentIndexX1;
			int32 ComponentIndexYY = ComponentIndexY - ComponentIndexY1;
			ComponentDataExist[ComponentIndexXY] = false;
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, ComponentIndexY));

			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			FColor* XYOffsetmapTextureData = NULL;
			uint8 CornerSet = 0;
			bool ExistLeft = ComponentIndexXX > 0 && ComponentDataExist[ComponentIndexXX - 1 + ComponentIndexYY * ComponentSizeX];
			bool ExistUp = ComponentIndexYY > 0 && ComponentDataExist[ComponentIndexXX + (ComponentIndexYY - 1) * ComponentSizeX];

			if (Component)
			{
				if (Component->XYOffsetmapTexture)
				{
					TexDataInfo = GetTextureDataInfo(Component->XYOffsetmapTexture);
					XYOffsetmapTextureData = (FColor*)TexDataInfo->GetMipData(0);
				}
				else
				{
					XYOffsetmapTextureData = EmptyXYOffset.GetData();
				}
				ComponentDataExist[ComponentIndexXY] = true;
				// Update valid region
				ValidX1 = FMath::Min<int32>(Component->GetSectionBase().X, ValidX1);
				ValidX2 = FMath::Max<int32>(Component->GetSectionBase().X + ComponentSizeQuads, ValidX2);
				ValidY1 = FMath::Min<int32>(Component->GetSectionBase().Y, ValidY1);
				ValidY2 = FMath::Max<int32>(Component->GetSectionBase().Y + ComponentSizeQuads, ValidY2);
			}
			else
			{
				if (!bHasMissingValue)
				{
					NoBorderY1.Empty(ComponentSizeX);
					NoBorderY2.Empty(ComponentSizeX);
					NoBorderY1.AddZeroed(ComponentSizeX);
					NoBorderY2.AddZeroed(ComponentSizeX);
					BorderComponentY1.Empty(ComponentSizeX);
					BorderComponentY2.Empty(ComponentSizeX);
					BorderComponentY1.AddZeroed(ComponentSizeX);
					BorderComponentY2.AddZeroed(ComponentSizeX);
					bHasMissingValue = true;
				}

				// Search for neighbor component for interpolation
				bool bShouldSearchX = (BorderComponent[1] && BorderComponent[1]->GetSectionBase().X / ComponentSizeQuads <= ComponentIndexX);
				bool bShouldSearchY = (BorderComponentY2[ComponentIndexXX] && BorderComponentY2[ComponentIndexXX]->GetSectionBase().Y / ComponentSizeQuads <= ComponentIndexY);
				// Search for left-closest component
				if (bShouldSearchX || (!NoBorderX1 && !BorderComponent[0]))
				{
					NoBorderX1 = true;
					for (int32 X = ComponentIndexX - 1; X >= ComponentIndexX1; X--)
					{
						BorderComponent[0] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X, ComponentIndexY));
						if (BorderComponent[0])
						{
							NoBorderX1 = false;
							if (BorderComponent[0]->XYOffsetmapTexture)
							{
								NeighborTexDataInfo[0] = GetTextureDataInfo(BorderComponent[0]->XYOffsetmapTexture);
								NeighborXYOffsetmapTextureData[0] = (FColor*)NeighborTexDataInfo[0]->GetMipData(0);
							}
							else
							{
								NeighborXYOffsetmapTextureData[0] = EmptyXYOffset.GetData();
							}
							break;
						}
					}
				}
				// Search for right-closest component
				if (bShouldSearchX || (!NoBorderX2 && !BorderComponent[1]))
				{
					NoBorderX2 = true;
					for (int32 X = ComponentIndexX + 1; X <= ComponentIndexX2; X++)
					{
						BorderComponent[1] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(X, ComponentIndexY));
						if (BorderComponent[1])
						{
							NoBorderX2 = false;
							if (BorderComponent[1]->XYOffsetmapTexture)
							{
								NeighborTexDataInfo[1] = GetTextureDataInfo(BorderComponent[1]->XYOffsetmapTexture);
								NeighborXYOffsetmapTextureData[1] = (FColor*)NeighborTexDataInfo[1]->GetMipData(0);
							}
							else
							{
								NeighborXYOffsetmapTextureData[1] = EmptyXYOffset.GetData();
							}
							break;
						}
					}
				}
				// Search for up-closest component
				if (bShouldSearchY || (!NoBorderY1[ComponentIndexXX] && !BorderComponentY1[ComponentIndexXX]))
				{
					NoBorderY1[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY - 1; Y >= ComponentIndexY1; Y--)
					{
						BorderComponentY1[ComponentIndexXX] = BorderComponent[2] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, Y));
						if (BorderComponent[2])
						{
							NoBorderY1[ComponentIndexXX] = false;
							if (BorderComponent[2]->XYOffsetmapTexture)
							{
								NeighborTexDataInfo[2] = GetTextureDataInfo(BorderComponent[2]->XYOffsetmapTexture);
								NeighborXYOffsetmapTextureData[2] = (FColor*)NeighborTexDataInfo[2]->GetMipData(0);
							}
							else
							{
								NeighborXYOffsetmapTextureData[2] = EmptyXYOffset.GetData();
							}
							break;
						}
					}
				}
				else
				{
					BorderComponent[2] = BorderComponentY1[ComponentIndexXX];
					if (BorderComponent[2])
					{
						if (BorderComponent[2]->XYOffsetmapTexture)
						{
							NeighborTexDataInfo[2] = GetTextureDataInfo(BorderComponent[2]->XYOffsetmapTexture);
							NeighborXYOffsetmapTextureData[2] = (FColor*)NeighborTexDataInfo[2]->GetMipData(0);
						}
						else
						{
							NeighborXYOffsetmapTextureData[2] = EmptyXYOffset.GetData();
						}

					}
				}
				// Search for bottom-closest component
				if (bShouldSearchY || (!NoBorderY2[ComponentIndexXX] && !BorderComponentY2[ComponentIndexXX]))
				{
					NoBorderY2[ComponentIndexXX] = true;
					for (int32 Y = ComponentIndexY + 1; Y <= ComponentIndexY2; Y++)
					{
						BorderComponentY2[ComponentIndexXX] = BorderComponent[3] = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX, Y));
						if (BorderComponent[3])
						{
							NoBorderY2[ComponentIndexXX] = false;
							if (BorderComponent[3]->XYOffsetmapTexture)
							{
								NeighborTexDataInfo[3] = GetTextureDataInfo(BorderComponent[3]->XYOffsetmapTexture);
								NeighborXYOffsetmapTextureData[3] = (FColor*)NeighborTexDataInfo[3]->GetMipData(0);
							}
							else
							{
								NeighborXYOffsetmapTextureData[3] = EmptyXYOffset.GetData();
							}
							break;
						}
					}
				}
				else
				{
					BorderComponent[3] = BorderComponentY2[ComponentIndexXX];
					if (BorderComponent[3])
					{
						if (BorderComponent[3]->XYOffsetmapTexture)
						{
							NeighborTexDataInfo[3] = GetTextureDataInfo(BorderComponent[3]->XYOffsetmapTexture);
							NeighborXYOffsetmapTextureData[3] = (FColor*)NeighborTexDataInfo[3]->GetMipData(0);
						}
						else
						{
							NeighborXYOffsetmapTextureData[3] = EmptyXYOffset.GetData();
						}
					}
				}

				CornerComponent[0] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX - 1), (ComponentIndexY - 1))) : NULL;
				CornerComponent[1] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY >= ComponentIndexY1 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX + 1), (ComponentIndexY - 1))) : NULL;
				CornerComponent[2] = ComponentIndexX >= ComponentIndexX1 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX - 1), (ComponentIndexY + 1))) : NULL;
				CornerComponent[3] = ComponentIndexX <= ComponentIndexX2 && ComponentIndexY <= ComponentIndexY2 ?
					LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint((ComponentIndexX + 1), (ComponentIndexY + 1))) : NULL;

				if (CornerComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetXYOffsetmapData(CornerComponent[0], EdgeCoord, EdgeCoord);
				}
				else if ((ExistLeft || ExistUp) && X1 <= ComponentIndexX*ComponentSizeQuads && Y1 <= ComponentIndexY*ComponentSizeQuads)
				{
					CornerSet |= 1;
					CornerValues[0] = FVector2D(StoreData.Load(ComponentIndexX*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads));
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1;
					CornerValues[0] = GetXYOffsetmapData(BorderComponent[0], EdgeCoord, 0, NeighborXYOffsetmapTextureData[0]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1;
					CornerValues[0] = GetXYOffsetmapData(BorderComponent[2], 0, EdgeCoord, NeighborXYOffsetmapTextureData[2]);
				}

				if (CornerComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetXYOffsetmapData(CornerComponent[1], 0, EdgeCoord);
				}
				else if (ExistUp && X2 >= (ComponentIndexX + 1)*ComponentSizeQuads)
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = FVector2D(StoreData.Load((ComponentIndexX + 1)*ComponentSizeQuads, ComponentIndexY*ComponentSizeQuads));
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetXYOffsetmapData(BorderComponent[1], 0, 0, NeighborXYOffsetmapTextureData[1]);
				}
				else if (BorderComponent[2])
				{
					CornerSet |= 1 << 1;
					CornerValues[1] = GetXYOffsetmapData(BorderComponent[2], EdgeCoord, EdgeCoord, NeighborXYOffsetmapTextureData[2]);
				}

				if (CornerComponent[2])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetXYOffsetmapData(CornerComponent[2], EdgeCoord, 0);
				}
				else if (ExistLeft && Y2 >= (ComponentIndexY + 1)*ComponentSizeQuads) // Use data already stored for 0, 2
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = FVector2D(StoreData.Load(ComponentIndexX*ComponentSizeQuads, (ComponentIndexY + 1)*ComponentSizeQuads));
				}
				else if (BorderComponent[0])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetXYOffsetmapData(BorderComponent[0], EdgeCoord, EdgeCoord, NeighborXYOffsetmapTextureData[0]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 2;
					CornerValues[2] = GetXYOffsetmapData(BorderComponent[3], 0, 0, NeighborXYOffsetmapTextureData[3]);
				}

				if (CornerComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetXYOffsetmapData(CornerComponent[3], 0, 0);
				}
				else if (BorderComponent[1])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetXYOffsetmapData(BorderComponent[1], 0, EdgeCoord, NeighborXYOffsetmapTextureData[1]);
				}
				else if (BorderComponent[3])
				{
					CornerSet |= 1 << 3;
					CornerValues[3] = GetXYOffsetmapData(BorderComponent[3], EdgeCoord, 0, NeighborXYOffsetmapTextureData[3]);
				}

				FillCornerValues(CornerSet, CornerValues);
				ComponentDataExist[ComponentIndexXY] = ExistLeft || ExistUp || (BorderComponent[0] || BorderComponent[1] || BorderComponent[2] || BorderComponent[3]) || CornerSet;
			}

			if (!ComponentDataExist[ComponentIndexXY])
			{
				continue;
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1 - ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1 - ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2 - ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2 - ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1 - 1) / SubsectionSizeQuads, 0, ComponentNumSubsections - 1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1 - 1) / SubsectionSizeQuads, 0, ComponentNumSubsections - 1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads, 0, ComponentNumSubsections - 1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads, 0, ComponentNumSubsections - 1);

			for (int32 SubIndexY = SubIndexY1; SubIndexY <= SubIndexY2; SubIndexY++)
			{
				for (int32 SubIndexX = SubIndexX1; SubIndexX <= SubIndexX2; SubIndexX++)
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1 - SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1 - SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2 - SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2 - SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for (int32 SubY = SubY1; SubY <= SubY2; SubY++)
					{
						for (int32 SubX = SubX1; SubX <= SubX2; SubX++)
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							// Find the input data corresponding to this vertex
							if (Component)
							{
								// Find the texture data corresponding to this vertex
								FVector2D XYOffset = GetXYOffsetmapData(Component, (SubsectionSizeQuads + 1) * SubIndexX + SubX, (SubsectionSizeQuads + 1) * SubIndexY + SubY, XYOffsetmapTextureData);
								StoreData.Store(LandscapeX, LandscapeY, XYOffset);
							}
							else
							{
								// Find the texture data corresponding to this vertex
								FVector2D Value[4] = { FVector2D::ZeroVector, FVector2D::ZeroVector, FVector2D::ZeroVector, FVector2D::ZeroVector };
								int32 Dist[4] = { INT_MAX, INT_MAX, INT_MAX, INT_MAX };
								FVector2D ValueX = FVector2D::ZeroVector, ValueY = FVector2D::ZeroVector;
								bool Exist[4] = { false, false, false, false };

								// Use data already stored for 0, 2
								if (ExistLeft)
								{
									Value[0] = FVector2D(StoreData.Load(ComponentIndexX*ComponentSizeQuads, LandscapeY));
									Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
									Exist[0] = true;
								}
								else if (BorderComponent[0])
								{
									Value[0] = GetXYOffsetmapData(BorderComponent[0], EdgeCoord, (SubsectionSizeQuads + 1) * SubIndexY + SubY, NeighborXYOffsetmapTextureData[0]);
									Dist[0] = LandscapeX - (BorderComponent[0]->GetSectionBase().X + ComponentSizeQuads);
									Exist[0] = true;
								}
								else
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 2))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY + 1)*ComponentSizeQuads) - LandscapeY;
										Value[0] = (Dist2 * CornerValues[0] + Dist1 * CornerValues[2]) / (Dist1 + Dist2);
										Dist[0] = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										Exist[0] = true;
									}
								}

								if (BorderComponent[1])
								{
									Value[1] = GetXYOffsetmapData(BorderComponent[1], 0, (SubsectionSizeQuads + 1) * SubIndexY + SubY, NeighborXYOffsetmapTextureData[1]);
									Dist[1] = (BorderComponent[1]->GetSectionBase().X) - LandscapeX;
									Exist[1] = true;
								}
								else
								{
									if ((CornerSet & 1 << 1) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										int32 Dist2 = ((ComponentIndexY + 1)*ComponentSizeQuads) - LandscapeY;
										Value[1] = (Dist2 * CornerValues[1] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[1] = (ComponentIndexX + 1)*ComponentSizeQuads - LandscapeX;
										Exist[1] = true;
									}
								}

								if (ExistUp)
								{
									Value[2] = FVector2D(StoreData.Load(LandscapeX, ComponentIndexY*ComponentSizeQuads));
									Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
									Exist[2] = true;
								}
								else if (BorderComponent[2])
								{
									Value[2] = GetXYOffsetmapData(BorderComponent[2], (SubsectionSizeQuads + 1) * SubIndexX + SubX, EdgeCoord, NeighborXYOffsetmapTextureData[2]);
									Dist[2] = LandscapeY - (BorderComponent[2]->GetSectionBase().Y + ComponentSizeQuads);
									Exist[2] = true;
								}
								else
								{
									if ((CornerSet & 1) && (CornerSet & 1 << 1))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX + 1)*ComponentSizeQuads - LandscapeX;
										Value[2] = (Dist2 * CornerValues[0] + Dist1 * CornerValues[1]) / (Dist1 + Dist2);
										Dist[2] = LandscapeY - (ComponentIndexY*ComponentSizeQuads);
										Exist[2] = true;
									}
								}

								if (BorderComponent[3])
								{
									Value[3] = GetXYOffsetmapData(BorderComponent[3], (SubsectionSizeQuads + 1) * SubIndexX + SubX, 0, NeighborXYOffsetmapTextureData[3]);
									Dist[3] = (BorderComponent[3]->GetSectionBase().Y) - LandscapeY;
									Exist[3] = true;
								}
								else
								{
									if ((CornerSet & 1 << 2) && (CornerSet & 1 << 3))
									{
										int32 Dist1 = LandscapeX - (ComponentIndexX*ComponentSizeQuads);
										int32 Dist2 = (ComponentIndexX + 1)*ComponentSizeQuads - LandscapeX;
										Value[3] = (Dist2 * CornerValues[2] + Dist1 * CornerValues[3]) / (Dist1 + Dist2);
										Dist[3] = (ComponentIndexY + 1)*ComponentSizeQuads - LandscapeY;
										Exist[3] = true;
									}
								}

								CalcInterpValue<FVector2D>(Dist, Exist, Value, ValueX, ValueY);

								FVector2D FinalValue = FVector2D::ZeroVector; // Default Value
								if ((Exist[0] || Exist[1]) && (Exist[2] || Exist[3]))
								{
									FinalValue = CalcValueFromValueXY<FVector2D>(Dist, ValueX, ValueY, CornerSet, CornerValues);
								}
								else if ((BorderComponent[0] || BorderComponent[1]))
								{
									FinalValue = ValueX;
								}
								else if ((BorderComponent[2] || BorderComponent[3]))
								{
									FinalValue = ValueY;
								}
								else if ((Exist[0] || Exist[1]))
								{
									FinalValue = ValueX;
								}
								else if ((Exist[2] || Exist[3]))
								{
									FinalValue = ValueY;
								}

								StoreData.Store(LandscapeX, LandscapeY, FinalValue);
								//StoreData.StoreDefault(LandscapeX, LandscapeY);
							}
						}
					}
				}
			}
		}
	}

	if (bHasMissingValue)
	{
		CalcMissingValues<FVector2D, TStoreData, FVector2D>(X1, X2, Y1, Y2,
			ComponentIndexX1, ComponentIndexX2, ComponentIndexY1, ComponentIndexY2,
			ComponentSizeX, ComponentSizeY, CornerValues,
			NoBorderY1, NoBorderY2, ComponentDataExist, StoreData);
		// Update valid region
		ValidX1 = FMath::Max<int32>(X1, ValidX1);
		ValidX2 = FMath::Min<int32>(X2, ValidX2);
		ValidY1 = FMath::Max<int32>(Y1, ValidY1);
		ValidY2 = FMath::Min<int32>(Y2, ValidY2);
	}
	else
	{
		ValidX1 = X1;
		ValidX2 = X2;
		ValidY1 = Y1;
		ValidY2 = Y2;
	}
}

void FLandscapeEditDataInterface::GetXYOffsetData(int32& X1, int32& Y1, int32& X2, int32& Y2, FVector2D* Data, int32 Stride)
{
	if (Stride == 0)
	{
		Stride = (1 + X2 - X1);
	}
	TArrayStoreData<FVector2D> ArrayStoreData(X1, Y1, Data, Stride);
	GetXYOffsetDataTempl(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetData(int32& X1, int32& Y1, int32& X2, int32& Y2, TMap<FIntPoint, FVector2D>& SparseData)
{
	TSparseStoreData<FVector2D> SparseStoreData(SparseData);
	GetXYOffsetDataTempl(X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetData(int32& X1, int32& Y1, int32& X2, int32& Y2, FVector* Data, int32 Stride)
{
	if (Stride == 0)
	{
		Stride = (1 + X2 - X1);
	}
	TArrayStoreData<FVector> ArrayStoreData(X1, Y1, Data, Stride);
	GetXYOffsetDataTempl(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetData(int32& X1, int32& Y1, int32& X2, int32& Y2, TMap<FIntPoint, FVector>& SparseData)
{
	TSparseStoreData<FVector> SparseStoreData(SparseData);
	GetXYOffsetDataTempl(X1, Y1, X2, Y2, SparseStoreData);
}

template<typename TStoreData>
void FLandscapeEditDataInterface::GetXYOffsetDataTemplFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TStoreData& StoreData)
{
	int32 ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2;
	ALandscape::CalcComponentIndicesNoOverlap(X1, Y1, X2, Y2, ComponentSizeQuads, ComponentIndexX1, ComponentIndexY1, ComponentIndexX2, ComponentIndexY2);

	for( int32 ComponentIndexY=ComponentIndexY1;ComponentIndexY<=ComponentIndexY2;ComponentIndexY++ )
	{
		for( int32 ComponentIndexX=ComponentIndexX1;ComponentIndexX<=ComponentIndexX2;ComponentIndexX++ )
		{		
			ULandscapeComponent* Component = LandscapeInfo->XYtoComponentMap.FindRef(FIntPoint(ComponentIndexX,ComponentIndexY));

			FLandscapeTextureDataInfo* TexDataInfo = NULL;
			FColor* OffsetTextureData = NULL;
			if( Component && Component->XYOffsetmapTexture )
			{
				TexDataInfo = GetTextureDataInfo(Component->XYOffsetmapTexture);
				OffsetTextureData = (FColor*)TexDataInfo->GetMipData(0);
			}

			// Find coordinates of box that lies inside component
			int32 ComponentX1 = FMath::Clamp<int32>(X1-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY1 = FMath::Clamp<int32>(Y1-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentX2 = FMath::Clamp<int32>(X2-ComponentIndexX*ComponentSizeQuads, 0, ComponentSizeQuads);
			int32 ComponentY2 = FMath::Clamp<int32>(Y2-ComponentIndexY*ComponentSizeQuads, 0, ComponentSizeQuads);

			// Find subsection range for this box
			int32 SubIndexX1 = FMath::Clamp<int32>((ComponentX1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);	// -1 because we need to pick up vertices shared between subsections
			int32 SubIndexY1 = FMath::Clamp<int32>((ComponentY1-1) / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexX2 = FMath::Clamp<int32>(ComponentX2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);
			int32 SubIndexY2 = FMath::Clamp<int32>(ComponentY2 / SubsectionSizeQuads,0,ComponentNumSubsections-1);

			for( int32 SubIndexY=SubIndexY1;SubIndexY<=SubIndexY2;SubIndexY++ )
			{
				for( int32 SubIndexX=SubIndexX1;SubIndexX<=SubIndexX2;SubIndexX++ )
				{
					// Find coordinates of box that lies inside subsection
					int32 SubX1 = FMath::Clamp<int32>(ComponentX1-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY1 = FMath::Clamp<int32>(ComponentY1-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);
					int32 SubX2 = FMath::Clamp<int32>(ComponentX2-SubsectionSizeQuads*SubIndexX, 0, SubsectionSizeQuads);
					int32 SubY2 = FMath::Clamp<int32>(ComponentY2-SubsectionSizeQuads*SubIndexY, 0, SubsectionSizeQuads);

					// Update texture data for the box that lies inside subsection
					for( int32 SubY=SubY1;SubY<=SubY2;SubY++ )
					{
						for( int32 SubX=SubX1;SubX<=SubX2;SubX++ )
						{
							int32 LandscapeX = SubIndexX*SubsectionSizeQuads + ComponentIndexX*ComponentSizeQuads + SubX;
							int32 LandscapeY = SubIndexY*SubsectionSizeQuads + ComponentIndexY*ComponentSizeQuads + SubY;

							// Find the input data corresponding to this vertex
							if( Component && OffsetTextureData )
							{
								FVector2D Value = GetXYOffsetmapData(Component, SubX, SubY, OffsetTextureData);
								StoreData.Store(LandscapeX, LandscapeY, Value);
							}
							else
							{
								StoreData.Store(LandscapeX, LandscapeY, FVector2D(0.0f, 0.0f) );
							}
						}
					}
				}
			}
		}
	}
}

void FLandscapeEditDataInterface::GetXYOffsetDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, FVector2D* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<FVector2D> ArrayStoreData(X1, Y1, Data, Stride);
	GetXYOffsetDataTemplFast(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, FVector2D>& SparseData)
{
	TSparseStoreData<FVector2D> SparseStoreData(SparseData);
	GetXYOffsetDataTemplFast(X1, Y1, X2, Y2, SparseStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, FVector* Data, int32 Stride)
{
	if( Stride==0 )
	{
		Stride = (1+X2-X1);
	}
	TArrayStoreData<FVector> ArrayStoreData(X1, Y1, Data, Stride);
	GetXYOffsetDataTemplFast(X1, Y1, X2, Y2, ArrayStoreData);
}

void FLandscapeEditDataInterface::GetXYOffsetDataFast(const int32 X1, const int32 Y1, const int32 X2, const int32 Y2, TMap<FIntPoint, FVector>& SparseData)
{
	TSparseStoreData<FVector> SparseStoreData(SparseData);
	GetXYOffsetDataTemplFast(X1, Y1, X2, Y2, SparseStoreData);
}

//
// FLandscapeTextureDataInfo
//

FLandscapeTextureDataInfo::FLandscapeTextureDataInfo(UTexture2D* InTexture)
:	Texture(InTexture)
{
	MipInfo.AddZeroed(Texture->Source.GetNumMips());
	Texture->SetFlags(RF_Transactional);
	Texture->TemporarilyDisableStreaming();
	Texture->Modify();
}

bool FLandscapeTextureDataInfo::UpdateTextureData()
{
	bool bNeedToWaitForUpdate = false;

	int32 DataSize = sizeof(FColor);
	if (Texture->GetPixelFormat() == PF_G8)
	{
		DataSize = sizeof(uint8);
	}

	for( int32 i=0;i<MipInfo.Num();i++ )
	{
		if( MipInfo[i].MipData && MipInfo[i].MipUpdateRegions.Num()>0 )
		{
			Texture->UpdateTextureRegions( i, MipInfo[i].MipUpdateRegions.Num(), &MipInfo[i].MipUpdateRegions[0], ((Texture->Source.GetSizeX())>>i)*DataSize, DataSize, (uint8*)MipInfo[i].MipData);
			bNeedToWaitForUpdate = true;
		}
	}

	return bNeedToWaitForUpdate;
}

FLandscapeTextureDataInfo::~FLandscapeTextureDataInfo()
{
	// Unlock any mips still locked.
	for( int32 i=0;i<MipInfo.Num();i++ )
	{
		if( MipInfo[i].MipData )
		{
			Texture->Source.UnlockMip(i);
			MipInfo[i].MipData = NULL;
		}
	}
	Texture->ClearFlags(RF_Transactional);
}

#endif // WITH_EDITOR