// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.

/*=============================================================================
	LocalVertexFactoryCommon.usf: Local vertex factory common functionality
=============================================================================*/

// FVertexFactoryInterpolantsVSToPS is split into a PC and ES2 version, since the ES2 version has more restrictions on packing
// Then accessors are provided for each property which try to encapsulate the packing differences
#if FEATURE_LEVEL >= FEATURE_LEVEL_SM3

struct FVertexFactoryInterpolantsVSToPS
{
	TANGENTTOWORLD_INTERPOLATOR_BLOCK

#if INTERPOLATE_VERTEX_COLOR
	half4	Color : COLOR0;
#endif

#if USE_INSTANCING
	// x = per-instance random, y = per-instance fade out amount, z = hide/show flag
	float3  PerInstanceParams : COLOR1;
#endif

#if NUM_MATERIAL_TEXCOORDS
	float4	TexCoords[(NUM_MATERIAL_TEXCOORDS+1)/2]	: TEXCOORD0;
#elif USE_PARTICLE_SUBUVS
	float4	TexCoords[1] : TEXCOORD0;
#endif

#if NEEDS_LIGHTMAP_COORDINATE
	float4	LightMapCoordinate : TEXCOORD4;
#endif
};

#if NUM_MATERIAL_TEXCOORDS || USE_PARTICLE_SUBUVS
float2 GetUV(FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex)
{
	float4 UVVector = Interpolants.TexCoords[UVIndex / 2];
	return UVIndex % 2 ? UVVector.zw : UVVector.xy;
}

void SetUV(inout FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex, float2 InValue)
{
	FLATTEN
	if (UVIndex % 2)
	{
		Interpolants.TexCoords[UVIndex / 2].zw = InValue;
	}
	else
	{
		Interpolants.TexCoords[UVIndex / 2].xy = InValue;
	}
}
#endif

float4 GetColor(FVertexFactoryInterpolantsVSToPS Interpolants)
{
#if INTERPOLATE_VERTEX_COLOR
	return Interpolants.Color;
#else
	return 0;
#endif
}

void SetColor(inout FVertexFactoryInterpolantsVSToPS Interpolants, float4 InValue)
{
#if INTERPOLATE_VERTEX_COLOR
	Interpolants.Color = InValue;
#endif
}

#if NEEDS_LIGHTMAP_COORDINATE
void GetLightMapCoordinates(FVertexFactoryInterpolantsVSToPS Interpolants, out float2 LightmapUV0, out float2 LightmapUV1)
{
	LightmapUV0 = Interpolants.LightMapCoordinate.xy * float2( 1, 0.5 );
	LightmapUV1 = LightmapUV0 + float2( 0, 0.5 );
}

float2 GetShadowMapCoordinate(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	return Interpolants.LightMapCoordinate.zw;
}

void SetLightMapCoordinate(inout FVertexFactoryInterpolantsVSToPS Interpolants, float4 InLightMapCoordinate, float2 InShadowMapCoordinate)
{
	Interpolants.LightMapCoordinate.xy = InLightMapCoordinate.xy;
	Interpolants.LightMapCoordinate.zw = InShadowMapCoordinate;
}
#endif

float4 GetTangentToWorld2(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	return Interpolants.TangentToWorld2;
}

float4 GetTangentToWorld0(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	return Interpolants.TangentToWorld0;
}

void SetTangents(inout FVertexFactoryInterpolantsVSToPS Interpolants, float3 InTangentToWorld0, float3 InTangentToWorld2, float InTangentToWorldSign)
{
	Interpolants.TangentToWorld0 = float4(InTangentToWorld0,0);
	Interpolants.TangentToWorld2 = float4(InTangentToWorld2,InTangentToWorldSign);
}


#else // #if FEATURE_LEVEL >= FEATURE_LEVEL_SM3

#define NUM_PACKED_UVS (NUM_MATERIAL_TEXCOORDS > 1 ? 3 : 1)

#define USE_INTERPOLATOR_345 ((!MATERIAL_SHADINGMODEL_UNLIT) || USES_TRANSFORM_VECTOR || USES_DISTORTION)

/** Interpolants packed for ES2.  All UVs are in the xy to ensure independent texture fetches. */
struct FVertexFactoryInterpolantsVSToPS
{
	// Save one interpolator if the material is only using one UV
#if NUM_PACKED_UVS == 1
	// UV0, normal xy
	float4 PackedUVs[1] : TEXCOORD0;

	#if INTERPOLATE_VERTEX_COLOR
		// Only interpolate vertex color if needed by the material pixel shader
		float4 Color : TEXCOORD1;
	#endif
#else
	// UV0, normal xy
	// UV1, color xy
	// UV2, color zw
	float4 PackedUVs[3] : TEXCOORD0;
#endif

#if USE_INTERPOLATOR_345
	// LightmapUV0, normal zw
	float4 PackedInterpolator3 : TEXCOORD3;

	// LightmapUV1, tangent xy
	float4 PackedInterpolator4 : TEXCOORD4;

	// ShadowmapUV, tangent zw
	float4 PackedInterpolator5 : TEXCOORD5;
#endif

#if USE_INSTANCING
	// x = per-instance random, y = per-instance fade out amount
	float3  PerInstanceParams : COLOR1;
#endif
};

float2 GetUV(FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex)
{
	return Interpolants.PackedUVs[UVIndex].xy;
}

void SetUV(inout FVertexFactoryInterpolantsVSToPS Interpolants, int UVIndex, float2 InValue)
{
	Interpolants.PackedUVs[UVIndex].xy = InValue;
}

float4 GetColor(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	#if NUM_PACKED_UVS == 1
		#if INTERPOLATE_VERTEX_COLOR
			return Interpolants.Color;
		#else
			return 0;
		#endif
	#else
		return float4(Interpolants.PackedUVs[1].zw, Interpolants.PackedUVs[2].zw);
	#endif
}

void SetColor(inout FVertexFactoryInterpolantsVSToPS Interpolants, float4 InValue)
{
	#if NUM_PACKED_UVS == 1
		#if INTERPOLATE_VERTEX_COLOR
			Interpolants.Color = InValue;
		#endif
	#else
		Interpolants.PackedUVs[1].zw = InValue.xy;
		Interpolants.PackedUVs[2].zw = InValue.zw;
	#endif
}

void GetLightMapCoordinates(FVertexFactoryInterpolantsVSToPS Interpolants, out float2 LightmapUV0, out float2 LightmapUV1)
{
	#if USE_INTERPOLATOR_345 
		LightmapUV0 = Interpolants.PackedInterpolator3.xy;
		LightmapUV1 = Interpolants.PackedInterpolator4.xy;
	#else
		LightmapUV0 = LightmapUV1 = 0;
	#endif
}

float2 GetShadowMapCoordinate(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	#if USE_INTERPOLATOR_345 
		return Interpolants.PackedInterpolator5.xy;
	#else
		return float2(0, 0);
	#endif
}

void SetLightMapCoordinate(inout FVertexFactoryInterpolantsVSToPS Interpolants, float4 InLightMapCoordinate, float2 InShadowMapCoordinate)
{
	#if USE_INTERPOLATOR_345
		Interpolants.PackedInterpolator3.xy = InLightMapCoordinate.xy;
		Interpolants.PackedInterpolator4.xy = InLightMapCoordinate.zw;
		Interpolants.PackedInterpolator5.xy = InShadowMapCoordinate;
	#endif
}

float4 GetTangentToWorld2(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	#if USE_INTERPOLATOR_345
		return float4(Interpolants.PackedUVs[0].zw, Interpolants.PackedInterpolator3.zw);
	#else
		return float4(0, 0, 0, 1);
	#endif
}

float4 GetTangentToWorld0(FVertexFactoryInterpolantsVSToPS Interpolants)
{
	#if USE_INTERPOLATOR_345
		return float4(Interpolants.PackedInterpolator4.zw, Interpolants.PackedInterpolator5.zw);
	#else
		return float4(0, 0, 0, 0);
	#endif
}

void SetTangents(inout FVertexFactoryInterpolantsVSToPS Interpolants, float3 InTangentToWorld0, float3 InTangentToWorld2, float InTangentToWorldSign)
{
	#if USE_INTERPOLATOR_345
		Interpolants.PackedInterpolator4.zw = InTangentToWorld0.xy;
		Interpolants.PackedInterpolator5.zw = InTangentToWorld0.zz;
		Interpolants.PackedUVs[0].zw = InTangentToWorld2.xy;
		Interpolants.PackedInterpolator3.zw = float2(InTangentToWorld2.z,InTangentToWorldSign);
	#else
		Interpolants.PackedUVs[0].zw = 0;
	#endif
}

#endif