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

// STATIC: "SFM"						"0..0" [vs20] [PC]
// STATIC: "SFM"						"0..1" [vs30] [PC]
// STATIC: "SFM"						"0..0" [CONSOLE]

// STATIC: "DECAL"							"0..1" [vs30]
// STATIC: "WORLD_NORMAL"					"0..0" [vs20] [PC]
// STATIC: "WORLD_NORMAL"					"0..1" [vs30] [PC]
// STATIC: "WORLD_NORMAL"					"0..0" [CONSOLE]
// STATIC: "FLATTEN_STATIC_CONTROL_FLOW"	"0..1" [vs20] [PC]
// STATIC: "FLATTEN_STATIC_CONTROL_FLOW"	"0..0" [CONSOLE]
// STATIC: "CASCADED_SHADOW_MAPPING"		"0..1" [vs20] [PC]
// STATIC: "CASCADED_SHADOW_MAPPING"		"0..0" [vs30] [PC]

// DYNAMIC: "CSM_VIEWMODELQUALITY"			"0..1" [vs20] [PC]
// DYNAMIC: "CSM_VIEWMODELQUALITY"			"0..0" [vs30] [PC]
// DYNAMIC: "COMPRESSED_VERTS"				"0..1"
// DYNAMIC: "SKINNING"						"0..1"
// DYNAMIC: "MORPHING"						"0..0" [ = false ]
// DYNAMIC: "TESSELLATION"					"0..0" [vs30] [PC]
// DYNAMIC: "TESSELLATION"					"0..0" [vs20] [PC]
// DYNAMIC: "TESSELLATION"					"0..0" [CONSOLE]
// DYNAMIC: "NUM_LIGHTS"					"0..2" [vs20] [PC]
// DYNAMIC: "NUM_LIGHTS"					"0..0" [vs20] [CONSOLE]
// DYNAMIC: "STATICLIGHT3"					"0..1" 

//	SKIP: ( $SFM == 0 ) && ( $MORPHING )
//	SKIP: ( $SFM == 0 ) && ( $TESSELLATION )

// 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: ( $MORPHING || $SKINNING || $COMPRESSED_VERTS ) && $TESSELLATION

#include "common_fog_vs_supportsvertexfog_fxc.h"
#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 );
const float4 cBumpTexCoordTransform[2]		: register( SHADER_SPECIFIC_CONST_2 );
const float4 cDetailTexCoordTransform[2]	: register( SHADER_SPECIFIC_CONST_4 );

#if ( MORPHING )
	// 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

const float4 g_vEyeVector					: register( SHADER_SPECIFIC_CONST_8 );

const float2 g_teamIdMinMax					: register( SHADER_SPECIFIC_CONST_10 );

#if ( CASCADED_SHADOW_MAPPING )
const float4x4 g_matWorldToShadowTexMatrices[2] : register( SHADER_SPECIFIC_CONST_CSM_0 );
const float4 g_matWorldToShadowTexMatrix0_z : register( SHADER_SPECIFIC_CONST_CSM_1 );
#endif

#if TESSELLATION

	// VS_INPUT defined in header
	#include "tessellation_vs_fxc.h"
	const float4 g_SubDControls					: register( SHADER_SPECIFIC_CONST_9 );
	sampler2D BezierSampler						: register( s1 );
	sampler2D DispSampler						: register( s2 );

#else // no TESSELLATION

	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;
		float4 vStaticLight				: COLOR1;
		#if STATICLIGHT3
			float4 vStaticLight2		: COLOR2;
			float4 vStaticLight3		: COLOR3;
		#endif
		// 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
		float4 vPosFlex					: POSITION1;
		float4 vNormalFlex				: NORMAL1;
	
	#if ( SFM )
		float vVertexID					: POSITION2;
	#endif
	};

#endif // TESSELLATION

struct VS_OUTPUT
{
	// Stuff that isn't seen by the pixel shader
	float4 projPos								: POSITION;	

	// Stuff that is seen by the pixel shader
	float4 baseTexCoord_baseTexCoord2			: TEXCOORD0;	// Base texture coordinates in .xy, 2nd (decal) uv set in .zw
	float4 bumpTexCoord_detailTexCoord			: TEXCOORD1;	

	float4 vWorldNormal_flTeamIdFade			: TEXCOORD2;
	float4 vWorldTangent						: TEXCOORD3;

	float4 vWorldPos_vertexFogFactor			: TEXCOORD4;
	float4 vProjPos_fWrinkleWeight				: TEXCOORD5;

	#if defined( SHADER_MODEL_VS_3_0 )
		float4 staticLight0						: TEXCOORD6;	// STATICLIGHT3 output basis 0 in .xyz, sun amount (if applicable) in .w 
		float4 staticLight1						: TEXCOORD7;	// STATICLIGHT3 output basis 1 in .xyz
		float4 staticLight2						: TEXCOORD8;	// STATICLIGHT3 output basis 2 in .xyz
		float4 lightAtten						: TEXCOORD9;	// light attenuation for 4 lights
	#else
		float4 csmXform0or1_csmXform2			: TEXCOORD6;
		float4 staticLight_csmXform0z			: TEXCOORD7;	// STATICLIGHT3 average rgb in .xyz, csm lightToWorldxformcascade0.z in .w
		float4 lightAtten						: COLOR0;		// light attenuation for lights 0 and 1 in .xy (lower precision for sm2_b/OSX), sun amount (if applicable) in .w
	#endif
};

float RemapValClamped( float val, float A, float B, float C, float D)
{
	float cVal = (val - A) / (B - A);
	cVal = saturate( cVal );

	return C + (D - C) * cVal;
}

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

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

	#if TESSELLATION
	{
		float flBiTangentSign;
		EvaluateSubdivisionSurface( v, g_SubDControls.x, g_SubDControls.y, g_SubDControls.z, BezierSampler, DispSampler,
								    worldNormal, worldPos, worldTangentS, worldTangentT, flBiTangentSign,
									o.vProjPos_fWrinkleWeight.w, o.baseTexCoord_baseTexCoord2.xy, o.bumpTexCoord_detailTexCoord.zw );
	}
	#else // not tessellating
	{
		vPosition = v.vPos;

		DecompressVertex_NormalTangent( v.vNormal, v.vUserData, vNormal, vTangent );

		#if ( !MORPHING )
		{
			ApplyMorph( v.vPosFlex, v.vNormalFlex.xyz, vPosition.xyz, vNormal, vTangent.xyz, o.vProjPos_fWrinkleWeight.w );
		}
		#else
		{
			ApplyMorph( morphSampler, cMorphTargetTextureDim, cMorphSubrect, v.vVertexID, v.vTexCoord2,
						vPosition.xyz, vNormal, vTangent.xyz, o.vProjPos_fWrinkleWeight.w );
		}
		#endif

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

		// Always normalize since flex path can denormalize
		worldNormal   = normalize( worldNormal );
		worldTangentS = normalize( worldTangentS );
		worldTangentT = normalize( worldTangentT );

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

		#if ( STATICLIGHT3 )
		{
			// for phong, to start with we'll try only baking indirect light from vrad - so that we don't lose the ability to acquire phong highlights
			// from map lights (including the sun/csm casting light) - direct lights will still come through as dynamic lights!

			#if defined( SHADER_MODEL_VS_3_0 )
				// Adjust lighting data (static lighting in linear space * cOverbright)
				o.staticLight0.rgb = GammaToLinear( v.vStaticLight.rgb * cOverbright );
				o.staticLight1.rgb = GammaToLinear( v.vStaticLight2.rgb * cOverbright );
				o.staticLight2.rgb = GammaToLinear( v.vStaticLight3.rgb * cOverbright );

				o.staticLight0.a = v.vStaticLight.a;
				o.staticLight1.a = v.vStaticLight2.a;
				o.staticLight2.a = v.vStaticLight3.a;
			#else
				// take average of STATICLIGHT3 data for shader model 2b (OSX)
				// Adjust lighting data (static lighting in linear space * cOverbright)
				o.staticLight_csmXform0z.rgb = GammaToLinear( v.vStaticLight.rgb * cOverbright );
				o.staticLight_csmXform0z.rgb += GammaToLinear( v.vStaticLight2.rgb * cOverbright );
				o.staticLight_csmXform0z.rgb += GammaToLinear( v.vStaticLight3.rgb * cOverbright );
				o.staticLight_csmXform0z.rgb *= 0.3333f;
			
				o.lightAtten.w = ( v.vStaticLight.a + v.vStaticLight2.a + v.vStaticLight3.a ) * 0.3333f;
			#endif
		}
		#endif

		vTexCoords = v.vTexCoord0;

		// Base texture coordinate transform
		o.baseTexCoord_baseTexCoord2.x = dot( vTexCoords, cBaseTexCoordTransform[0] );
		o.baseTexCoord_baseTexCoord2.y = dot( vTexCoords, cBaseTexCoordTransform[1] );

		// 2nd uv set, pass through for now
		o.baseTexCoord_baseTexCoord2.zw = v.vTexCoord1.xy;

		// bump texture coordinate transform - temp
		o.bumpTexCoord_detailTexCoord.x = dot( v.vTexCoord0, cBumpTexCoordTransform[0] );
		o.bumpTexCoord_detailTexCoord.y = dot( v.vTexCoord0, cBumpTexCoordTransform[1] );

		// Detail texture coordinate transform
		o.bumpTexCoord_detailTexCoord.z = dot( v.vTexCoord0, cDetailTexCoordTransform[0] );
		o.bumpTexCoord_detailTexCoord.w = dot( v.vTexCoord0, cDetailTexCoordTransform[1] );
	}
	#endif
	
	#if ( !DOPIXELFOG )
	{
		o.vWorldPos_vertexFogFactor.w = CalcNonFixedFunctionFog( worldPos, g_FogType );
	}
	#endif

	// Needed for water fog alpha and diffuse lighting 
	// FIXME: we shouldn't have to compute this all the time.
	o.vWorldPos_vertexFogFactor.xyz = worldPos;

	// Compute lighting attenuations
	#if ( defined ( SHADER_MODEL_VS_2_0 ) && FLATTEN_STATIC_CONTROL_FLOW )
	{
		#if ( NUM_LIGHTS > 0 )
			o.lightAtten.x = GetVertexAttenForLight( worldPos.xyz, 0, false );
		#endif
		#if ( NUM_LIGHTS > 1 )
			o.lightAtten.y = GetVertexAttenForLight( worldPos.xyz, 1, false );
		#endif
	}
	#else
	{
		o.lightAtten.x = GetVertexAttenForLight( worldPos, 0 );
		o.lightAtten.y = GetVertexAttenForLight( worldPos, 1 );
#if defined( SHADER_MODEL_VS_3_0 )
		o.lightAtten.z = GetVertexAttenForLight( worldPos, 2 );
		o.lightAtten.w = GetVertexAttenForLight( worldPos, 3 );
#endif
	}
	#endif

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

	// Transform into projection space
	o.projPos = mul( float4( worldPos, 1 ), cViewProj );
	
#ifdef _PS3
	// Account for OpenGL's flipped y coordinate and expanded z range [-1,1] instead of [0,1]
	o.projPos.y = -o.projPos.y;
	o.projPos.z = 2.0f * o.projPos.z - o.projPos.w;
#endif // _PS3

	o.vProjPos_fWrinkleWeight.xyz = o.projPos.xyz;

	#if ( WORLD_NORMAL )
	{
		o.vProjPos_fWrinkleWeight.z = dot( g_vEyeVector, worldPos.xyz - cEyePos.xyz );	// Linear depth
	}
	#endif

	// Don't have to worry about hardware blend here since we never do that with phong.
	#if ( !DOPIXELFOG )
	{
		o.vWorldPos_vertexFogFactor.w = CalcNonFixedFunctionFog( worldPos, g_FogType );
	}
	#endif

	o.vWorldNormal_flTeamIdFade.w = RemapValClamped( distance( cEyePos, worldPos.xyz ), g_teamIdMinMax.x, g_teamIdMinMax.y, 0.0, 1.0 );

	#if( CASCADED_SHADOW_MAPPING )
	{
		float4 worldPos = float4( o.vWorldPos_vertexFogFactor.xyz, 1.0f );

		#if CSM_VIEWMODELQUALITY
			o.csmXform0or1_csmXform2.xy	= mul( worldPos, g_matWorldToShadowTexMatrices[0] ).xy;
		#else
			o.csmXform0or1_csmXform2.xy	= mul( worldPos, g_matWorldToShadowTexMatrices[0] ).xy; 
			o.csmXform0or1_csmXform2.zw	= mul( worldPos, g_matWorldToShadowTexMatrices[1] ).xy;
		#endif
		
		o.staticLight_csmXform0z.w		= mul( worldPos, g_matWorldToShadowTexMatrix0_z );
	}
	#endif

	return o;
}