UnrealEngineUWP/Engine/Shaders/ConvertToUniformMesh.usf

// Copyright 1998-2017 Epic Games, Inc. All Rights Reserved.

/*=============================================================================
	ConvertToUniformMesh.usf
=============================================================================*/

#include "Common.usf"
#include "Material.usf"
#include "VertexFactory.usf"

struct FConvertToUniformMeshVSToGS
{
	FVertexFactoryInterpolantsVSToPS FactoryInterpolants;
	float3 PixelPosition : TEXCOORD6;
};

void ConvertToUniformMeshVS(
	FVertexFactoryInput Input,
	out FConvertToUniformMeshVSToGS Output
	)
{
	ResolvedView = ResolveView();

	FVertexFactoryIntermediates VFIntermediates = GetVertexFactoryIntermediates(Input);
	float3 WorldPosition = VertexFactoryGetWorldPosition(Input, VFIntermediates).xyz - ResolvedView.PreViewTranslation.xyz;
	float3x3 TangentToLocal = VertexFactoryGetTangentToLocal(Input, VFIntermediates);

	FMaterialVertexParameters VertexParameters = GetMaterialVertexParameters(Input, VFIntermediates, WorldPosition, TangentToLocal);

	Output.FactoryInterpolants = VertexFactoryGetInterpolantsVSToPS(Input, VFIntermediates, VertexParameters);
	Output.PixelPosition = WorldPosition;
}

// Must match GetUniformMeshStreamOutLayout and TRIANGLE_VERTEX_DATA_STRIDE
struct FConvertToUniformMeshVertex
{
	float4 Position : SV_Position;
	float3 Tangent0 : Tangent0;
	float3 Tangent1 : Tangent1;
	float3 Tangent2 : Tangent2;
	float2 UV0 : UV0;
	float2 UV1 : UV1;
	float4 VertexColor : VertexColor;
};

[maxvertexcount(3)]
void ConvertToUniformMeshGS(triangle FConvertToUniformMeshVSToGS Inputs[3], inout TriangleStream<FConvertToUniformMeshVertex> OutStream)
{ 
	for (int i = 0; i < 3; i++)
	{
		FConvertToUniformMeshVSToGS Input = Inputs[i];

		float4 DummySvPosition;
		FMaterialPixelParameters MaterialParameters = GetMaterialPixelParameters(Input.FactoryInterpolants, DummySvPosition);

		FConvertToUniformMeshVertex Vertex = (FConvertToUniformMeshVertex)0;
		Vertex.Position = float4(Input.PixelPosition, 40);

		Vertex.Tangent0 = MaterialParameters.TangentToWorld[0];
		Vertex.Tangent1 = MaterialParameters.TangentToWorld[1];
		Vertex.Tangent2 = MaterialParameters.TangentToWorld[2];

		Vertex.UV0 = Vertex.UV1 = 0;

		#if NUM_MATERIAL_TEXCOORDS > 0
			Vertex.UV0 = MaterialParameters.TexCoords[0];
		#endif

		#if NUM_MATERIAL_TEXCOORDS > 1
			Vertex.UV1 = MaterialParameters.TexCoords[1];
		#endif

		Vertex.VertexColor = MaterialParameters.VertexColor;

		OutStream.Append(Vertex);
	}
}