//======= Copyright © 1996-2008, Valve Corporation, All rights reserved. ======
//  STATIC: "HALFLAMBERT"			"0..1"
//  STATIC: "USE_WITH_2B"			"0..1"
//  STATIC: "DECAL"					"0..1" [vs30]
//  STATIC: "FLASHLIGHT"			"0..1" [XBOX]

//  DYNAMIC: "COMPRESSED_VERTS"		"0..1"
//	DYNAMIC: "DOWATERFOG"			"0..1"
//	DYNAMIC: "SKINNING"				"0..1"
//  DYNAMIC: "MORPHING"				"0..1" [vs30]

#include "common_vs_fxc.h"

static const bool g_bSkinning		= SKINNING ? true : false;
static const int g_FogType			= DOWATERFOG;

const float4 cBaseTexCoordTransform[2]	 :  register( SHADER_SPECIFIC_CONST_0 );	// 0 & 1
const float4 cDetailTexCoordTransform[2] :  register( SHADER_SPECIFIC_CONST_4 );	// 4 & 5
const float4x4 g_FlashlightWorldToTexture :  register( SHADER_SPECIFIC_CONST_6 );	// 6, 7, 8, 9

#ifdef SHADER_MODEL_VS_3_0
// NOTE: cMorphTargetTextureDim.xy = target dimensions,
//		 cMorphTargetTextureDim.z = 4tuples/morph
const float3 cMorphTargetTextureDim			: register( SHADER_SPECIFIC_CONST_10 );
const float4 cMorphSubrect					: register( SHADER_SPECIFIC_CONST_11 );

sampler2D morphSampler : register( D3DVERTEXTEXTURESAMPLER0, s0 );
#endif


//-----------------------------------------------------------------------------
// Input vertex format
//-----------------------------------------------------------------------------
struct VS_INPUT
{
	// This is all of the stuff that we ever use.
	float4 vPos				: POSITION;
	float4 vBoneWeights		: BLENDWEIGHT;
	float4 vBoneIndices		: BLENDINDICES;
	float4 vNormal			: NORMAL;
	float4 vColor			: COLOR0;
	float3 vSpecular		: COLOR1;
	// make these float2's and stick the [n n 0 1] in the dot math.
	float4 vTexCoord0		: TEXCOORD0;
	float4 vTexCoord1		: TEXCOORD1;
	float4 vTexCoord2		: TEXCOORD2;
	float4 vTexCoord3		: TEXCOORD3;
	float3 vTangentS		: TANGENT;
	float3 vTangentT		: BINORMAL;
	float4 vUserData		: TANGENT;

	// Position and normal/tangent deltas
	float3 vPosFlex			: POSITION1;
	float3 vNormalFlex		: NORMAL1;
#ifdef SHADER_MODEL_VS_3_0
	float vVertexID			: POSITION2;
#endif
};


//-----------------------------------------------------------------------------
// Output vertex format
//-----------------------------------------------------------------------------
struct VS_OUTPUT
{
	// Stuff that isn't seen by the pixel shader
	float4 projPos												: POSITION;	
#if !defined( _X360 )
	float  fog													: FOG;
#endif
	// Stuff that is seen by the pixel shader

	float4 baseTexCoord2_tangentSpaceVertToEyeVectorXY			: TEXCOORD0;
	float3 lightAtten											: TEXCOORD1;
	float4 worldVertToEyeVectorXYZ_tangentSpaceVertToEyeVectorZ	: TEXCOORD2;
	float3 vWorldNormal											: TEXCOORD3;	// World-space normal
	float4 vWorldTangent										: TEXCOORD4;
#if	USE_WITH_2B
	float4 vProjPos												: TEXCOORD5;
#else
	float3 vWorldBinormal										: TEXCOORD5;
#endif
	float4 worldPos_projPosZ									: TEXCOORD6;
	float3 detailTexCoord_atten3								: TEXCOORD7;
	float4 fogFactorW											: COLOR1;

#if defined( _X360 ) && FLASHLIGHT
	float4 flashlightSpacePos									: TEXCOORD8;
#endif
};


//-----------------------------------------------------------------------------
// Main shader entry point
//-----------------------------------------------------------------------------
VS_OUTPUT main( const VS_INPUT v )
{
	VS_OUTPUT o = ( VS_OUTPUT )0;

	float4 vPosition = v.vPos;
	float3 vNormal;
	float4 vTangent;
	DecompressVertex_NormalTangent( v.vNormal, v.vUserData, vNormal, vTangent );

#if !defined( SHADER_MODEL_VS_3_0 ) || !MORPHING
	ApplyMorph( v.vPosFlex, v.vNormalFlex, vPosition.xyz, vNormal, vTangent.xyz );
#else
	ApplyMorph( morphSampler, cMorphTargetTextureDim, cMorphSubrect, 
		v.vVertexID, v.vTexCoord2, vPosition.xyz, vNormal, vTangent.xyz );
#endif

	// Perform skinning
	float3 worldNormal, worldPos, worldTangentS, worldTangentT;
	SkinPositionNormalAndTangentSpace( g_bSkinning, vPosition, vNormal, vTangent,
		v.vBoneWeights, v.vBoneIndices, worldPos,
		worldNormal, worldTangentS, worldTangentT );

	// Always normalize since flex path is controlled by runtime
	// constant not a shader combo and will always generate the normalization
	worldNormal   = normalize( worldNormal );
	worldTangentS = normalize( worldTangentS );
	worldTangentT = normalize( worldTangentT );

#if defined( SHADER_MODEL_VS_3_0 ) && MORPHING && DECAL
	// Avoid z precision errors
	worldPos += worldNormal * 0.05f * v.vTexCoord2.z;
#endif

	o.vWorldNormal.xyz = worldNormal.xyz;
	o.vWorldTangent = float4( worldTangentS.xyz, vTangent.w );	 // Propagate binormal sign in world tangent.w

	// Transform into projection space
	float4 projPos = mul( float4( worldPos, 1 ), cViewProj );
	o.projPos = projPos;

#if USE_WITH_2B
	o.vProjPos = projPos;
#else
	o.vWorldBinormal.xyz = worldTangentT.xyz;
#endif

	o.fogFactorW = CalcFog( worldPos, projPos, g_FogType );
#if !defined( _X360 )
	o.fog = o.fogFactorW;
#endif

 	// Needed for water fog alpha and diffuse lighting
	// FIXME: we shouldn't have to compute this all the time.
	o.worldPos_projPosZ = float4( worldPos, projPos.z );

	// Needed for cubemapping + parallax mapping
	// FIXME: We shouldn't have to compute this all the time.
	//o.worldVertToEyeVectorXYZ_tangentSpaceVertToEyeVectorZ.xyz = VSHADER_VECT_SCALE * (cEyePos - worldPos);
	o.worldVertToEyeVectorXYZ_tangentSpaceVertToEyeVectorZ.xyz = normalize( cEyePos.xyz - worldPos.xyz );

	// Scalar light attenuation
	o.lightAtten.x = GetVertexAttenForLight( worldPos, 0 );
	o.lightAtten.y = GetVertexAttenForLight( worldPos, 1 );
	o.lightAtten.z = GetVertexAttenForLight( worldPos, 2 );
	o.detailTexCoord_atten3.z = GetVertexAttenForLight( worldPos, 3 );

	// Base texture coordinate transform
	o.baseTexCoord2_tangentSpaceVertToEyeVectorXY.x = dot( v.vTexCoord0, cBaseTexCoordTransform[0] );
	o.baseTexCoord2_tangentSpaceVertToEyeVectorXY.y = dot( v.vTexCoord0, cBaseTexCoordTransform[1] );

	// Detail texture coordinate transform
	o.detailTexCoord_atten3.x = dot( v.vTexCoord0, cDetailTexCoordTransform[0] );
	o.detailTexCoord_atten3.y = dot( v.vTexCoord0, cDetailTexCoordTransform[1] );

#if defined( _X360 ) && FLASHLIGHT
	o.flashlightSpacePos = mul( float4( worldPos, 1.0f ), g_FlashlightWorldToTexture );
#endif

	return o;
}
