MaterialExpressionMaterialAttributeLayers.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "MaterialExpressionIO.h"
#include "Materials/MaterialExpression.h"
#include "Materials/MaterialLayersFunctions.h"
#include "MaterialExpressionMaterialAttributeLayers.generated.h"
 
class FMaterialCompiler;
class UMaterialFunctionInterface;
class UMaterialExpressionMaterialFunctionCall;
struct FMaterialParameterInfo;
 
constexpr int8 AcceptableNumLayerMAInputs = 1;
constexpr int8 AcceptableNumBlendMAInputs = 2;
constexpr int8 AcceptableNumLayerBlendMAOutputs = 1;
 
UCLASS(hidecategories=Object, MinimalAPI)
class UMaterialExpressionMaterialAttributeLayers : public UMaterialExpression
{
    GENERATED_UCLASS_BODY()
 
    UPROPERTY()
    FMaterialAttributesInput Input;
    
    UPROPERTY(EditAnywhere, Category=Layers)
    FMaterialLayersFunctions DefaultLayers;
 
    const TArray<UMaterialFunctionInterface*>& GetLayers() const
    {
        return ParamLayers ? ParamLayers->Layers : DefaultLayers.Layers;
    }
 
    const TArray<UMaterialFunctionInterface*>& GetBlends() const
    {
        return ParamLayers ? ParamLayers->Blends : DefaultLayers.Blends;
    }
 
#if WITH_EDITOR
    const TArray<FText>& GetLayerNames() const
    {
        return ParamLayers ? ParamLayers->EditorOnly.LayerNames : DefaultLayers.EditorOnly.LayerNames;
    }
 
    const TArray<bool>& GetShouldFilterLayers() const
    {
        return ParamLayers ? ParamLayers->EditorOnly.RestrictToLayerRelatives : DefaultLayers.EditorOnly.RestrictToLayerRelatives;
    }
 
    const TArray<bool>& GetShouldFilterBlends() const
    {
        return ParamLayers ? ParamLayers->EditorOnly.RestrictToBlendRelatives : DefaultLayers.EditorOnly.RestrictToBlendRelatives;
    }
 
    const TArray<FGuid>& GetLayerGuids() const
    {
        return ParamLayers ? ParamLayers->EditorOnly.LayerGuids : DefaultLayers.EditorOnly.LayerGuids;
    }
 
    const TArray<bool>& GetLayerStates() const
    {
        return ParamLayers ? ParamLayers->EditorOnly.LayerStates : DefaultLayers.EditorOnly.LayerStates;
    }
#endif // WITH_EDITOR
 
    UPROPERTY(Transient)
    TArray<TObjectPtr<UMaterialExpressionMaterialFunctionCall>> LayerCallers;
 
    UPROPERTY(Transient)
    int32 NumActiveLayerCallers = 0;
 
    UPROPERTY(Transient)
    TArray<TObjectPtr<UMaterialExpressionMaterialFunctionCall>> BlendCallers;
 
    UPROPERTY(Transient)
    int32 NumActiveBlendCallers = 0;
 
    UPROPERTY(Transient)
    TObjectPtr<UMaterialExpressionMaterialFunctionCall> OutputCaller;
 
    UPROPERTY(Transient)
    bool bIsLayerGraphBuilt = false;
 
    //~ Begin UObject Interface
    virtual void PostLoad() override;
#if WITH_EDITOR
    virtual void PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent) override;
#endif
    //~ Begin UObject Interface
 
#if WITH_EDITOR
    ENGINE_API virtual void RebuildLayerGraph(bool bReportErrors);
    ENGINE_API void OverrideLayerGraph(const FMaterialLayersFunctions* OverrideLayers);
#endif // WITH_EDITOR
 
#if WITH_EDITOR
    static void LogError(FMaterialCompiler* Compiler, const TCHAR* Format, ...);
    virtual bool ValidateLayerConfiguration(FMaterialCompiler* Compiler, bool bReportErrors);
#endif // WITH_EDITOR
 
#if WITH_EDITORONLY_DATA
    bool IterateDependentFunctions(TFunctionRef<bool(UMaterialFunctionInterface*)> Predicate) const;
    void GetDependentFunctions(TArray<UMaterialFunctionInterface*>& DependentFunctions) const;
#endif
 
    UMaterialFunctionInterface* GetParameterAssociatedFunction(const FHashedMaterialParameterInfo& ParameterInfo) const;
 
    //~ Begin UMaterialExpression Interface
#if WITH_EDITOR
    virtual int32 Compile(FMaterialCompiler* Compiler, int32 OutputIndex) override;
    virtual void GetCaption(TArray<FString>& OutCaptions) const override;
    virtual void GetExpressionToolTip(TArray<FString>& OutToolTip) override;
    virtual FName GetInputName(int32 InputIndex) const override;
    virtual bool IsInputConnectionRequired(int32 InputIndex) const override {return false;}
    virtual EMaterialValueType GetInputValueType(int32 InputIndex) override;
    virtual bool IsResultMaterialAttributes(int32 OutputIndex) override {return true;}
    virtual bool IsResultSubstrateMaterial(int32 OutputIndex) override {return false;}
#endif
    //~ End UMaterialExpression Interface
 
protected:
    const FMaterialLayersFunctions* ParamLayers = nullptr;
};