MaterialExpressionRuntimeVirtualTextureSample.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Engine/EngineTypes.h"
#include "Materials/MaterialExpression.h"
#include "UObject/ObjectMacros.h"
#include "VT/RuntimeVirtualTexture.h"
#include "MaterialExpressionRuntimeVirtualTextureSample.generated.h"
 
UENUM()
enum ERuntimeVirtualTextureMipValueMode : int
{
    /* 
     * Use default computed mip level. Takes into account UV scaling from using the WorldPosition pin.
     */
    RVTMVM_None UMETA(DisplayName = "Default"),
 
    /* 
     * Use an absolute mip level from the MipLevel pin. 
     * 0 is full resolution.
     */
    RVTMVM_MipLevel UMETA(DisplayName = "Mip Level"),
 
    /* 
     * Bias the default computed mip level using the MipBias pin. 
     * Negative values increase resolution.
     */
    RVTMVM_MipBias UMETA(DisplayName = "Mip Bias"),
 
    /* 
    * Compute mip level from world position derivatives.
    * This is intended for cases where the value passed to the WorldPosition pin doesn't give good derivatives.
    * (For example when using a constant value from primitive world position).
    * This is deprecated. Use Derivative (World Space) instead, and pass in DDX/DDY of world space.
     */
    RVTMVM_RecalculateDerivatives UMETA(Hidden, DisplayName = "Ignore Input WorldPosition"),
 
    /* 
     * Compute mip level from explicitly provided DDX and DDY derivatives of the virtual texture UV coordinates.
     */
    RVTMVM_DerivativeUV UMETA(DisplayName = "Derivatives (UV Space)"),
 
    /*
     * Compute mip level from explicitly provided DDX and DDY derivatives of the world position.
     */
     RVTMVM_DerivativeWorld UMETA(DisplayName = "Derivatives (World Space)"),
 
    RVTMVM_MAX,
};
 
UENUM()
enum ERuntimeVirtualTextureTextureAddressMode : int
{
    /* Clamp mode. */
    RVTTA_Clamp UMETA(DisplayName = "Clamp"),
    /* Wrap mode. */
    RVTTA_Wrap UMETA(DisplayName = "Wrap"),
 
    RVTTA_MAX,
};
 
enum class EVirtualTextureUnpackType
{
    None,
    BaseColorYCoCg,
    NormalBC3,
    NormalBC5,
    NormalBC3BC3,
    NormalBC5BC1,
    HeightR16,
    NormalBGR565,
    BaseColorSRGB,
    DisplacementR16,
};
 
struct FRuntimeVirtualTextureUnpackProperties
{
    bool bIsBaseColorValid : 1 = false;
    bool bIsSpecularValid : 1 = false;
    bool bIsRoughnessValid : 1 = false;
    bool bIsNormalValid : 1 = false;
    bool bIsWorldHeightValid : 1 = false;
    bool bIsMaskValid : 1 = false;
    bool bIsMask4Valid : 1 = false;
    bool bIsDisplacementValid : 1 = false;
 
    uint32 UnpackTarget = 0;
    uint32 UnpackMask = 0;
    EVirtualTextureUnpackType UnpackType = EVirtualTextureUnpackType::None;
    TArray<float, TInlineAllocator<4>> ConstantVector;
};
 
UCLASS(collapsecategories, hidecategories=Object, MinimalAPI)
class UMaterialExpressionRuntimeVirtualTextureSample : public UMaterialExpression
{
    GENERATED_UCLASS_BODY()
 
    
    UPROPERTY(meta = (RequiredInput = "false"))
    FExpressionInput Coordinates;
 
    UPROPERTY(meta = (RequiredInput = "false"))
    FExpressionInput WorldPosition;
 
    UPROPERTY(meta = (RequiredInput = "false"))
    FExpressionInput MipValue;
 
    UPROPERTY(meta = (RequiredInput = "false"))
    FExpressionInput DDX;
    
    UPROPERTY(meta = (RequiredInput = "false"))
    FExpressionInput DDY;
 
    UPROPERTY(EditAnywhere, Category = VirtualTexture)
    TObjectPtr<class URuntimeVirtualTexture> VirtualTexture;
 
    UPROPERTY(EditAnywhere, Category = VirtualTexture, meta = (DisplayName = "Virtual texture content"))
    ERuntimeVirtualTextureMaterialType MaterialType = ERuntimeVirtualTextureMaterialType::BaseColor;
 
    UPROPERTY(EditAnywhere, Category = VirtualTexture, meta = (DisplayName = "Enable packed page table"))
    bool bSinglePhysicalSpace = true;
 
    UPROPERTY(EditAnywhere, Category = VirtualTexture, meta = (DisplayName = "Enable adaptive page table"))
    bool bAdaptive = false;
 
    UPROPERTY(EditAnywhere, Category = "UV Coordinates")
    EPositionOrigin WorldPositionOriginType = EPositionOrigin::Absolute;
 
    UPROPERTY(EditAnywhere, Category = TextureSample)
    TEnumAsByte<enum ERuntimeVirtualTextureTextureAddressMode> TextureAddressMode = RVTTA_Clamp;
 
    UPROPERTY(EditAnywhere, Category = TextureSample)
    TEnumAsByte<enum ERuntimeVirtualTextureMipValueMode> MipValueMode = RVTMVM_None;
 
    UPROPERTY(EditAnywhere, Category = TextureSample)
    bool bEnableFeedback = true;
 
    ENGINE_API bool InitVirtualTextureDependentSettings();
 
    ESamplerSourceMode GetSamplerSourceMode() const;
 
protected:
    ENGINE_API void InitOutputs();
 
    //~ Begin UMaterialExpression Interface
    ENGINE_API virtual UObject* GetReferencedTexture() const override;
    virtual bool CanReferenceTexture() const { return true; }
 
#if WITH_EDITOR
    ENGINE_API virtual void PostLoad() override;
    FExpressionInput* GetInput(int32 InputIndex) override;
    ENGINE_API virtual FName GetInputName(int32 InputIndex) const override;
    ENGINE_API virtual void Build(MIR::FEmitter& Emitter) override;
    ENGINE_API virtual int32 Compile(class FMaterialCompiler* Compiler, int32 OutputIndex) override;
    ENGINE_API virtual void GetCaption(TArray<FString>& OutCaptions) const override;
    ENGINE_API virtual bool CanEditChange(const FProperty* InProperty) const override;
 
    bool ValidateVirtualTextureParameters(FString& OutError) const;
 
    bool IsParameter() const;
 
    bool GetRVTUnpackProperties(int32 OutputIndex, bool bIsVirtualTextureValid, FRuntimeVirtualTextureUnpackProperties& Output) const;
 
public:
    ENGINE_API virtual void PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent) override;
 
#endif
    //~ End UMaterialExpression Interface
};