UShaderLab/Source/UShaderLabEditor/Private/ShaderLabIntrinsics_DistanceField.cpp

// Copyright UShaderLab. All Rights Reserved.
//
// Global-distance-field intrinsics. These names are OVERLOADED (bAllowRawHelperWithArgs): the nullary form
// UE_DistanceToNearestSurface() / UE_DistanceFieldGradient() is this wired intrinsic (its real node reads the
// current pixel's world position and sets bUsesGlobalDistanceField), while UE_Name(worldPos) is a same-named
// raw HLSL helper in UEFunctions/DistanceField.ush whose binding is supplied by the "GlobalDistanceField"
// anchor capability. The parser routes a call with args to the helper and a nullary call to this node.

#include "ShaderLabIntrinsics.h"

#include "Materials/MaterialExpressionDistanceToNearestSurface.h"
#include "Materials/MaterialExpressionDistanceFieldGradient.h"

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

	{
		FShaderLabIntrinsicDesc Desc;
		Desc.Name = TEXT("DistanceToNearestSurface");
		Desc.Frequency = EFreq::Any;
		Desc.ReturnType = TEXT("float");
		Desc.bAllowRawHelperWithArgs = true;
		Desc.MakeNode = [](UMaterial& M, const TArray<FString>&, FString&)
		{
			return MakeSimple<UMaterialExpressionDistanceToNearestSurface>(M);
		};
		Registry.Register(MoveTemp(Desc));
	}
	{
		FShaderLabIntrinsicDesc Desc;
		Desc.Name = TEXT("DistanceFieldGradient");
		Desc.Frequency = EFreq::Any;
		Desc.ReturnType = TEXT("float3");
		Desc.bAllowRawHelperWithArgs = true;
		Desc.MakeNode = [](UMaterial& M, const TArray<FString>&, FString&)
		{
			return MakeSimple<UMaterialExpressionDistanceFieldGradient>(M);
		};
		Registry.Register(MoveTemp(Desc));
	}
}