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

// STATIC: "HALFLAMBERT"					"0..1"
// STATIC: "FLATTEN_STATIC_CONTROL_FLOW"	"0..1" [vs20] [PC]
// STATIC: "FLATTEN_STATIC_CONTROL_FLOW"	"0..0" [CONSOLE]

// DYNAMIC: "COMPRESSED_VERTS"				"0..1"
#include "common_fog_vs_fxc.h"
// DYNAMIC: "SKINNING"						"0..1"

// DYNAMIC: "MORPHING"						"0..0" [ = false ]
// DYNAMIC: "NUM_LIGHTS"					"0..2" [vs20] [PC]
// DYNAMIC: "NUM_LIGHTS"					"0..0" [vs20] [CONSOLE]

// If using static control flow on Direct3D, we should use the NUM_LIGHTS=0 combo
// SKIP: ( $FLATTEN_STATIC_CONTROL_FLOW == 0 ) && ( $NUM_LIGHTS > 0 ) [vs20] [PC]

// SKIP: $DOWATERFOG

#include "vortwarp_vs20_helper.h"

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

const float4 cBaseTexCoordTransform[2]	:  register( SHADER_SPECIFIC_CONST_0 );

const float4 const4	:  register( SHADER_SPECIFIC_CONST_4 );
#define g_Time const4.w
#define modelOrigin const4.xyz

#ifdef SHADER_MODEL_VS_3_0
// NOTE: cMorphTargetTextureDim.xy = target dimensions,
//		 cMorphTargetTextureDim.z = 4tuples/morph
const float3 cMorphTargetTextureDim		: register( SHADER_SPECIFIC_CONST_6 );
const float4 cMorphSubrect				: register( SHADER_SPECIFIC_CONST_7 );

sampler2D morphSampler					: register( 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
{
    float4 projPos					: POSITION;	
#if !defined( _X360 ) && !defined( SHADER_MODEL_VS_3_0 )
	float  fog						: FOG;
#endif

	float4 baseTexCoord2_tangentSpaceVertToEyeVectorXY			: TEXCOORD0;
	// bump mapping and a separate envmap mask texture are mutually exclusive.
	float4 lightAtten											: TEXCOORD1;
	float4 worldVertToEyeVectorXYZ_tangentSpaceVertToEyeVectorZ	: TEXCOORD2;
	float3x3 tangentSpaceTranspose								: TEXCOORD3;
	//	     second row											: TEXCOORD4;
	//	     third row											: TEXCOORD5;
	float4 worldPos_projPosZ									: TEXCOORD6;
};

//-----------------------------------------------------------------------------
// 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, float3( 0, 0, 0 ),
		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 );

	WorldSpaceVertexProcess( g_Time, modelOrigin, 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 );

	// Transform into projection space
	float4 projPos = mul( float4( worldPos, 1 ), cViewProj );
	o.projPos = projPos;
	
#if !defined( _X360 ) && !defined( SHADER_MODEL_VS_3_0 )
	o.fog = CalcFixedFunctionFog( worldPos, g_FogType );
#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);

#if ( defined ( SHADER_MODEL_VS_2_0 ) && ( FLATTEN_STATIC_CONTROL_FLOW ) )
	o.lightAtten = float4(0,0,0,0);
	#if ( NUM_LIGHTS > 0 )
		o.lightAtten.x = GetVertexAttenForLight( worldPos, 0, false );
	#endif
	#if ( NUM_LIGHTS > 1 )
		o.lightAtten.y = GetVertexAttenForLight( worldPos, 1, false );
	#endif
	#if ( NUM_LIGHTS > 2 )
		o.lightAtten.z = GetVertexAttenForLight( worldPos, 2, false );
	#endif
	#if ( NUM_LIGHTS > 3 )
		o.lightAtten.w = GetVertexAttenForLight( worldPos, 3, false );
	#endif
#else
	// Scalar light attenuation
	o.lightAtten.x = GetVertexAttenForLight( worldPos, 0, true );
	o.lightAtten.y = GetVertexAttenForLight( worldPos, 1, true );
	o.lightAtten.z = GetVertexAttenForLight( worldPos, 2, true );
	o.lightAtten.w = GetVertexAttenForLight( worldPos, 3, true );
#endif

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

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

	return o;
}