// Copyright UShaderLab. All Rights Reserved.
//
// Per-instance intrinsics.

#include "ShaderLabIntrinsics.h"

#include "Materials/MaterialExpressionPerInstanceCustomData.h"
#include "Materials/MaterialExpressionPerInstanceFadeAmount.h"
#include "Materials/MaterialExpressionPerInstanceRandom.h"

void RegisterInstancingIntrinsics(FShaderLabIntrinsicRegistry& Registry)
{
	using namespace ShaderLabIntrinsic_Private;
	using EFreq = EShaderLabIntrinsicFrequency;

	AddSimple(Registry, TEXT("PerInstanceRandom"), EFreq::Any, TEXT("float"), [](UMaterial& M) { return MakeSimple<UMaterialExpressionPerInstanceRandom>(M); });
	AddSimple(Registry, TEXT("PerInstanceFadeAmount"), EFreq::Any, TEXT("float"), [](UMaterial& M) { return MakeSimple<UMaterialExpressionPerInstanceFadeAmount>(M); });

	// PerInstanceCustomData(DataIndex[, ConstDefaultValue]) — const args + optional input pin at default.
	{
		FShaderLabIntrinsicDesc Desc;
		Desc.Name = FName(TEXT("PerInstanceCustomData"));
		Desc.ReturnType = TEXT("float");
		Desc.Params = { { TEXT("int"), TEXT("DataIndex"), TEXT("") },
						{ TEXT("float"), TEXT("ConstDefaultValue"), TEXT("0") } };
		Desc.MakeNode = [](UMaterial& M, const TArray<FString>& Args, FString&) -> UMaterialExpression*
		{
			UMaterialExpressionPerInstanceCustomData* E = NewObject<UMaterialExpressionPerInstanceCustomData>(&M);
			if (Args.Num() >= 1) { E->DataIndex = static_cast<uint32>(FCString::Atoi(*Args[0])); }
			if (Args.Num() >= 2) { E->ConstDefaultValue = FCString::Atof(*Args[1]); }
			M.GetExpressionCollection().AddExpression(E);
			return E;
		};
		Registry.Register(MoveTemp(Desc));
	}
}