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

/*=============================================================================
	ShadowDepthCommon.usf: Shared functionality for shadow depth rendering.
=============================================================================*/

#ifndef PERSPECTIVE_CORRECT_DEPTH
#define PERSPECTIVE_CORRECT_DEPTH 0
#endif

#ifndef REFLECTIVE_SHADOW_MAP
#define REFLECTIVE_SHADOW_MAP 0
#endif

#define INTERPOLATE_VF_ATTRIBUTES (!MATERIALBLENDING_SOLID || REFLECTIVE_SHADOW_MAP || MATERIALBLENDING_MASKED || (REQUIRES_VF_ATTRIBUTES_FOR_CLIPPING && !POSITION_ONLY))
#define INTERPOLATE_POSITION ((REFLECTIVE_SHADOW_MAP && !ONEPASS_POINTLIGHT_SHADOW) || MATERIALBLENDING_MASKED)

// x: Tweakable depth bias, y:InvMaxSubjectDepthUsed to normalize the outputted depth
float2 ShadowParams;

/** Data passed from the vertex shader to the pixel shader for the shadow depth pass. */
struct FShadowDepthVSToPS
{
#if INTERPOLATE_VF_ATTRIBUTES
	FVertexFactoryInterpolantsVSToPS FactoryInterpolants;
#endif

#if ONEPASS_POINTLIGHT_SHADOW
	float4 GSPosition : TEXCOORD6;

#elif PERSPECTIVE_CORRECT_DEPTH
	float ShadowDepth : TEXCOORD6;

#elif !COMPILER_SUPPORTS_EMPTY_STRUCTS
	float Dummy : TEXCOORD6;

#endif

#if INTERPOLATE_POSITION
	// world space position needed in some cases, could be changed to be reconsructed from SvPosition (more tricky as this is not from camera perspective)
	float3 PixelPosition	: TEXCOORD7;
#endif
};