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

// STATIC: "VERTEXCOLOR"		"0..1"
// STATIC: "BUMPMAP"			"0..2"

// DYNAMIC: "NUM_LIGHTS"		"0..4"					[ps20b]
// DYNAMIC: "NUM_LIGHTS"		"0..4"					[ps30]
// DYNAMIC: "AMBIENT_LIGHT"		"0..1"

// Includes =======================================================================================
#include "common_vertexlitgeneric_dx9.h"

// Texture Samplers ===============================================================================
sampler g_tColorSampler				: register( s0 );
sampler g_tBumpSampler				: register( s1 );
sampler g_tDummySampler				: register( s2 );

// Shaders Constants and Globals ==================================================================
const float4 g_mViewProj0			: register( c0 );	// 1st row of matrix
const float4 g_mViewProj1			: register( c1 );	// 2nd row of matrix
const float4 g_vCameraPosition		: register( c2 );
const float3 g_ambientCube[6]		: register( c3 );
								  //: register( c4 );
								  //: register( c5 );
								  //: register( c6 );
								  //: register( c7 );
								  //: register( c8 );

PixelShaderLightInfo g_lightInfo[3]	: register( c9 ); // 2 registers each - 6 registers total
								  //: register( c10 );
								  //: register( c11 );
								  //: register( c12 );
								  //: register( c13 );
								  //: register( c14 );


// new-UP
static const float3 upBumpBasis[3] = {
	float3(  0.0f, 0.81649661064147949f, OO_SQRT_3 ),
	float3( -0.70710676908493042f, -0.40824833512306213f, OO_SQRT_3 ),
	float3(  0.7071068286895752f, -0.40824821591377258f, OO_SQRT_3 )
};


// Interpolated values ============================================================================
struct PS_INPUT
{
	float3 vUv0					: TEXCOORD0;
	float3 vWorldNormal			: TEXCOORD1;
	float3 vWorldTangent		: TEXCOORD2;
	float3 vWorldBinormal		: TEXCOORD3;
	float3 vWorldPosition		: TEXCOORD4;
	float4 vLightAtten			: TEXCOORD5;
	float4 vSpecularPack1		: TEXCOORD6;
	float4 vSpecularPack2		: TEXCOORD7;
	#if ( VERTEXCOLOR )
		float4 vVertexColor		: COLOR0;
	#endif
};

// Main ===========================================================================================
float4 main( PS_INPUT i ) : COLOR
{
	// Unpack lighting information
	float3 vSpecularN1 = i.vSpecularPack1.xyz;
	float3 vSpecularN2 = i.vSpecularPack2.xyz;
	float3 vSpecularN3;
	vSpecularN3.x = i.vSpecularPack1.w;
	vSpecularN3.y = i.vSpecularPack2.w;
	vSpecularN3.z = i.vUv0.z;

	// Color
	float4 cBaseColor = tex2D( g_tColorSampler, i.vUv0.xy );

	#if BUMPMAP == 0
	// non-bumped case
		float3 vTangentNormal = float3( 0, 0, 1 );
	#elif BUMPMAP == 1
	// Combine bump layers into tangent normal
		float4 vBumpTexel = tex2D( g_tBumpSampler, i.vUv0.xy );
		float3 vTangentNormal = ( vBumpTexel * 2.0f ) - 1.0f;
	#elif BUMPMAP == 2
	// ssbump case
		float4 vBumpTexel = tex2D( g_tBumpSampler, i.vUv0.xy );
		float3 vTangentNormal = vBumpTexel;
	#endif

	// Lighting
	float3 cDiffuse = float3( 0.0f, 0.0f, 0.0f );
	#if ( VERTEXCOLOR )
	{
		// Use interpolated vertex colors
		cDiffuse.rgb = i.vVertexColor.rgb;
	}
	#else
	{
		// Compute lighting
//		cDiffuse.rgb = PixelShaderDoLighting( i.vWorldPosition.xyz, normalize( vWorldNormal.xyz ),
//				float3( 0.0f, 0.0f, 0.0f ), false, AMBIENT_LIGHT, i.vLightAtten.xyzw,
//				g_ambientCube, g_tDummySampler, NUM_LIGHTS, g_lightInfo, false,
//				false, g_tDummySampler );
#if BUMPMAP == 0
		cDiffuse.rgb = ( vSpecularN1 + vSpecularN2 + vSpecularN3 ) / 3.0f;
#elif BUMPMAP == 1
		float3 dp;
		dp.x = saturate( dot( vTangentNormal, upBumpBasis[0] ) );
		dp.y = saturate( dot( vTangentNormal, upBumpBasis[1] ) );
		dp.z = saturate( dot( vTangentNormal, upBumpBasis[2] ) );
		dp *= dp;

		cDiffuse.rgb = dp.x * vSpecularN1 + dp.y * vSpecularN2 + dp.z * vSpecularN3;
#elif BUMPMAP == 2
		float3 dp;
		dp.x = saturate( dot( vTangentNormal, upBumpBasis[0] ) );
		dp.y = saturate( dot( vTangentNormal, upBumpBasis[1] ) );
		dp.z = saturate( dot( vTangentNormal, upBumpBasis[2] ) );
		dp *= dp;

		cDiffuse.rgb = dp.x * vSpecularN1 + dp.y * vSpecularN2 + dp.z * vSpecularN3;

		// ssbump case needs to construct tangent normal from ssbump vector
		vTangentNormal.xyz = normalize( bumpBasis[0]*vTangentNormal.x +
								bumpBasis[1]*vTangentNormal.y + bumpBasis[2]*vTangentNormal.z);
#endif
	}
	#endif

	#if 0
	// Transform normal into world space
	float3 vWorldNormal = Vec3TangentToWorld( vTangentNormal.xyz, i.vWorldNormal.xyz, i.vWorldTangent.xyz, i.vWorldBinormal.xyz );
	#endif

	//===============//
	// Combine terms //
	//===============//
	float4 result;
	result.rgb = cBaseColor.rgb;
	result.rgb *= cDiffuse.rgb;

	// Set alpha to...
	result.a = 0.0f;

	return FinalOutput( result, 0, PIXEL_FOG_TYPE_NONE, TONEMAP_SCALE_LINEAR ); //go back to final output when it'll fit.
}