MaterialExpressionLandscapeGrassOutput.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 "MaterialValueType.h"
#include "Materials/MaterialExpressionCustomOutput.h"
#include "MaterialExpressionLandscapeGrassOutput.generated.h"
 
class ULandscapeGrassType;
struct FPropertyChangedEvent;
 
USTRUCT()
struct FGrassInput
{
    GENERATED_USTRUCT_BODY()
 
    UPROPERTY(EditAnywhere, Category = Grass)
    FName Name;
 
    UPROPERTY(EditAnywhere, Category = Grass)
    TObjectPtr<ULandscapeGrassType> GrassType;
 
    UPROPERTY(meta = (RequiredInput = "true"))
    FExpressionInput Input;
 
    FGrassInput()
    : GrassType(nullptr)
    {}
    
    FGrassInput(FName InName)
    : Name(InName)
    , GrassType(nullptr)
    {}
};
 
UCLASS(collapsecategories, hidecategories=Object, MinimalAPI)
class UMaterialExpressionLandscapeGrassOutput : public UMaterialExpressionCustomOutput
{
    GENERATED_UCLASS_BODY()
 
    // Maximum number of supported grass types on a given landscape material. Whenever adjusting this, make sure to update LandscapeGrassWeight.usf accordingly:
    static constexpr int32 MaxGrassTypes = 32;
 
#if WITH_EDITOR
    LANDSCAPE_API virtual int32 Compile(class FMaterialCompiler* Compiler, int32 OutputIndex) override;
    LANDSCAPE_API virtual void GetCaption(TArray<FString>& OutCaptions) const override;
    LANDSCAPE_API virtual TArrayView<FExpressionInput*> GetInputsView() override;
    LANDSCAPE_API virtual FExpressionInput* GetInput(int32 InputIndex) override;
    LANDSCAPE_API virtual FName GetInputName(int32 InputIndex) const override;
    LANDSCAPE_API void ValidateInputName(FGrassInput& Input) const;
#endif
 
    //~ Begin UObject Interface
#if WITH_EDITOR
    LANDSCAPE_API virtual void PostEditChangeProperty(FPropertyChangedEvent& PropertyChangedEvent) override;
    //~ End UObject Interface
 
    virtual EMaterialValueType GetInputValueType(int32 InputIndex) override { return MCT_Float; }
#endif
 
    virtual int32 GetNumOutputs() const override { return GrassTypes.Num(); }
    virtual int32 GetMaxOutputs() const { return MaxGrassTypes; };
    virtual FString GetFunctionName() const override { return TEXT("GetGrassWeight"); }
 
    UPROPERTY(EditAnywhere, Category = UMaterialExpressionLandscapeGrassOutput)
    TArray<FGrassInput> GrassTypes;
 
private:
    static LANDSCAPE_API FName PinDefaultName;
};