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

//  STATIC: "MODEL"				"0..1"

#include "common_fog_vs_fxc.h"
//	DYNAMIC: "SKINNING"			"0..1"
//  DYNAMIC: "MORPHING"			"0..1" [vs30] [ = pShaderAPI->IsHWMorphingEnabled() ]
//  STATIC: "SPECULAR"			"0..1"
//  STATIC: "FLASHLIGHT"		"0..1"
//  STATIC: "FOW"				"0..1"

#include "common_vs_fxc.h"
#include "fow_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_6 );
const float4 g_vFoWWorldSize						: register( c26 );
const float4 g_vRotations							: register( c27 );
const float4 g_vScales								: register( c28 );
const float4 g_vLightDir							: register( c29 );	// xyz = light dir, w = spec power

#if ( FLASHLIGHT == 1 )
	
const float4x4 g_FlashlightWorldToTexture : register( SHADER_SPECIFIC_CONST_0 );

#endif


struct VS_INPUT
{
	float3 vPos							: POSITION;
	float4 vNormal						: NORMAL;
	float2 vBaseTexCoord				: TEXCOORD0;
	float2 vLightmapTexCoord			: TEXCOORD1;
//	float2 vLightmapTexCoordOffset		: TEXCOORD2;
	float4 vAlphaBlend					: TEXCOORD3;
	float4 vColorBlend1					: TEXCOORD4;
	float4 vColorBlend2					: TEXCOORD5;
	float4 vColorBlend3					: TEXCOORD6;
	float4 vColorBlend4					: TEXCOORD7;
};

struct VS_OUTPUT
{
	float4 vProjPos							: POSITION;	
	float4 vBaseTexCoord					: TEXCOORD0;	// xy = blend 1 coord, zw = lightmap cord
	float4 worldPos_projPosZ				: TEXCOORD1;
#if FLASHLIGHT
	float4 vFlashlightSpacePos				: TEXCOORD2;
#endif
	float4 vFowCoord						: TEXCOORD3;	// xy = fow, zw = blend4 coord
	float4 vAlphaBlend						: TEXCOORD4;	// xyz = alpha blend of 1, 2, 3.  w = flSpecPower
//	float3 worldVertToEyeVector				: TEXCOORD5;
	float4 vBlendCoords23					: TEXCOORD5;
	float4 vColorBlend1						: COLOR0;
	float4 vColorBlend2						: COLOR1;
	float4 vColorBlend3						: TEXCOORD6;
	float3 vColorBlend4						: TEXCOORD7;
};

float2 ComputeTexCoord( const float2 vBaseCoord, const float flRotation, const float flScale )
{
	float2 	vAdjust = vBaseCoord - float2( 0.5, 0.5 );
	float2 	vResult;
	float 	c = cos( flRotation );
	float 	s = sin( flRotation );
	
   	vResult.x = ( vAdjust.x * c ) + ( vAdjust.y * -s );
   	vResult.y = ( vAdjust.x * s ) + ( vAdjust.y * c );
   	
   	return ( vResult / flScale ) + float2( 0.5, 0.5 );
}

VS_OUTPUT main( const VS_INPUT v )
{
	VS_OUTPUT o;

	float3 vObjNormal;
	DecompressVertex_Normal( v.vNormal, vObjNormal );

	float4 vProjPos;
	float3 vWorldPos;

	vProjPos = mul( float4( v.vPos, 1 ), cModelViewProj );
	o.vProjPos = vProjPos;

	vWorldPos = mul( float4( v.vPos, 1 ), cModel[0] );
	
	o.worldPos_projPosZ.w = vProjPos.z;
	o.worldPos_projPosZ.xyz = vWorldPos;
	
#if ( FOW == 1 )
	o.vFowCoord.xy = CalcFoWCoord( g_vFoWWorldSize, vWorldPos.xy );
#else
	o.vFowCoord.xy = float2( 0.0, 0.0 );
#endif

	float3 vWorldNormal = mul( vObjNormal, ( float3x3 )cModel[0] );

	o.vBaseTexCoord.xy = ComputeTexCoord( v.vBaseTexCoord, g_vRotations.x, g_vScales.x );
	o.vBlendCoords23.xy = ComputeTexCoord( v.vBaseTexCoord, g_vRotations.y, g_vScales.y );
	o.vBlendCoords23.zw = ComputeTexCoord( v.vBaseTexCoord, g_vRotations.z, g_vScales.z );
	o.vFowCoord.zw = ComputeTexCoord( v.vBaseTexCoord, g_vRotations.w, g_vScales.w );
	
	o.vBaseTexCoord.zw = v.vLightmapTexCoord; // + v.vLightmapTexCoordOffset;
	
	o.vColorBlend1 = v.vColorBlend1;
	o.vColorBlend2 = v.vColorBlend2;
	o.vColorBlend3 = v.vColorBlend3;
	o.vColorBlend4.xyz = v.vColorBlend4.xyz;
	o.vAlphaBlend.xyz = v.vAlphaBlend.xyz;
	
#if ( SPECULAR == 1 )

	float3 vWorldVertToEyeVector = cEyePos - vWorldPos;
	float3	vView = normalize( vWorldVertToEyeVector );
	float3	vReflect = reflect( g_vLightDir, vWorldNormal );
	float	fDot = dot( vView, vReflect );
	o.vAlphaBlend.w = saturate( pow( saturate( fDot ), g_vLightDir.w ) );

#else

	o.vAlphaBlend.w = 0;

#endif

#if ( FLASHLIGHT == 1 )

	o.vFlashlightSpacePos = mul( float4( vWorldPos, 1.0f ), g_FlashlightWorldToTexture );
	o.vBaseTexCoord.zw = vProjPos.xy / vProjPos.w;

#endif

	return o;
}