//========== Copyright (c) Valve Corporation, All rights reserved. ==========//

// STATIC:	"MIRROR"					"0..1"
// STATIC:	"NORMALMAP"					"0..1"

// DYNAMIC: "SKINNING"					"0..1"
// DYNAMIC: "COMPRESSED_VERTS"			"0..1"
// DYNAMIC: "NUM_LIGHTS"				"0..4"

#include "common_vs_fxc.h"

const float4 g_patternTexCoordTransform[2]		: register( SHADER_SPECIFIC_CONST_0 ); // 0 & 1

const float4 g_const2							: register( SHADER_SPECIFIC_CONST_2 );
#define g_flAspectRatioHeight g_const2.x

static const bool g_bSkinning = SKINNING ? true : false;

struct VS_INPUT
{
	float4 vPos					: POSITION;
	float2 vTexCoord			: TEXCOORD0;
	float4 vNormal				: NORMAL;
#if ( NORMALMAP == 1 )
	float4 vTangent				: TANGENT;
#endif
	float4 vBoneWeights			: BLENDWEIGHT;
	float4 vBoneIndices			: BLENDINDICES;
};

struct VS_OUTPUT
{
	float4 vProjPos				: POSITION;
	float4 vBaseUV_PatternUV	: TEXCOORD0;
	float4 lightAtten			: TEXCOORD2;
	float3 worldPos				: TEXCOORD3;
#if ( NORMALMAP == 1 )
	float3x3 tangentSpaceTranspose	: TEXCOORD4;
	//	     second row				: TEXCOORD5;
	//	     third row				: TEXCOORD6;
#else
	float3   vWorldNormal			: TEXCOORD4;
#endif
};

// Main
VS_OUTPUT main( const VS_INPUT i )
{
	VS_OUTPUT o;

	float4 vPosition, vTangent;
	float3 vNormal, worldPos, worldNormal, worldTangentS, worldTangentT;

	vPosition = i.vPos;

	// Perform skinning
	#if ( NORMALMAP == 0 )
		DecompressVertex_Normal( i.vNormal, vNormal );
		SkinPositionAndNormal( g_bSkinning, vPosition, vNormal, i.vBoneWeights, i.vBoneIndices, worldPos, worldNormal );

		worldNormal   = normalize( worldNormal );
		o.vWorldNormal = worldNormal;
	#else
		DecompressVertex_NormalTangent( i.vNormal, i.vTangent, vNormal, vTangent );
		SkinPositionNormalAndTangentSpace( g_bSkinning, vPosition, vNormal, vTangent,
											i.vBoneWeights, i.vBoneIndices, worldPos,
											worldNormal, worldTangentS, worldTangentT );
		worldTangentS = normalize( worldTangentS );
		worldTangentT = normalize( worldTangentT );
		worldNormal   = normalize( worldNormal );

		// Tangent space transform
		o.tangentSpaceTranspose[0].xyz = float3( worldTangentS.x, worldTangentT.x, worldNormal.x );
		o.tangentSpaceTranspose[1].xyz = float3( worldTangentS.y, worldTangentT.y, worldNormal.y );
		o.tangentSpaceTranspose[2].xyz = float3( worldTangentS.z, worldTangentT.z, worldNormal.z );
	#endif

	// Bump out the decal so it doesn't z-fight with coplanar polys.
	// This means we don't have to push decal faces in content, and may dial this value globally if needed.
	worldPos -= normalize( worldPos.xyz - cEyePos.xyz ) * 0.05;

	o.worldPos = worldPos;
	o.vProjPos = mul( float4( worldPos, 1.0f ), cViewProj );

	o.lightAtten.x = GetVertexAttenForLight( worldPos, 0 );
	o.lightAtten.y = GetVertexAttenForLight( worldPos, 1 );
	o.lightAtten.z = GetVertexAttenForLight( worldPos, 2 );
	o.lightAtten.w = GetVertexAttenForLight( worldPos, 3 );

	o.vBaseUV_PatternUV.xy = i.vTexCoord;
	#if (MIRROR == 0)
		o.vBaseUV_PatternUV.z = dot ( i.vTexCoord, g_patternTexCoordTransform[0].xy ) + g_patternTexCoordTransform[0].w;
		o.vBaseUV_PatternUV.w = dot ( i.vTexCoord, g_patternTexCoordTransform[1].xy ) + g_patternTexCoordTransform[1].w;
	#else
		float2 flippedTexCoord = float2( 1.0f - i.vTexCoord.x, i.vTexCoord.y );
		o.vBaseUV_PatternUV.z = dot ( flippedTexCoord, g_patternTexCoordTransform[0].xy ) + g_patternTexCoordTransform[0].w;
		o.vBaseUV_PatternUV.w = dot ( flippedTexCoord, g_patternTexCoordTransform[1].xy ) + g_patternTexCoordTransform[1].w;
	#endif

	//maintain input texture aspect ratio
	o.vBaseUV_PatternUV.zw = float2( o.vBaseUV_PatternUV.z, ( (o.vBaseUV_PatternUV.w - 0.5f) * g_flAspectRatioHeight ) + 0.5f );

	//o.vWearUV_GrungeUV.x = dot ( i.vTexCoord, g_wearTexCoordTransform[0].xy ) + g_wearTexCoordTransform[0].w;
	//o.vWearUV_GrungeUV.y = dot ( i.vTexCoord, g_wearTexCoordTransform[1].xy ) + g_wearTexCoordTransform[1].w;
	//o.vWearUV_GrungeUV.z = dot ( i.vTexCoord, g_grungeTexCoordTransform[0].xy ) + g_grungeTexCoordTransform[0].w;
	//o.vWearUV_GrungeUV.w = dot ( i.vTexCoord, g_grungeTexCoordTransform[1].xy ) + g_grungeTexCoordTransform[1].w;

	return o;
}