float4x4 view_proj_matrix;
float4x4 view_matrix;
float4x4 inv_view_matrix;
float4 light_position;
float4 eye_position;


struct VS_INPUT_STRUCT
{
   float4 position:     POSITION;
   float3 tangent:      TANGENT;
   float3 normal:       NORMAL;
   float2 texcoord0:    TEXCOORD0;
};

struct VS_OUTPUT_STRUCT
{
   float4 position:     POSITION;
   float2 bump_map:     TEXCOORD0;
   float3 tangentlight: TEXCOORD1;
   float3 half_angle:   TEXCOORD2;
   float3 tangenteye:   TEXCOORD3;
};


VS_OUTPUT_STRUCT main( VS_INPUT_STRUCT vsInStruct )
{
   VS_OUTPUT_STRUCT vsOutStruct;

   vsOutStruct.position = mul( view_proj_matrix, vsInStruct.position );
   float3 position =  mul( view_matrix, vsInStruct.position );
   vsOutStruct.bump_map = vsInStruct.texcoord0;

   float3x3 tangentspace_matrix = float3x3(vsInStruct.tangent,cross(vsInStruct.tangent, vsInStruct.normal),vsInStruct.normal);
  
   float3 objectspace_light_vector = mul( inv_view_matrix, light_position ) - vsInStruct.position; 
   vsOutStruct.tangentlight =  mul( tangentspace_matrix, objectspace_light_vector );  
  
   float3 objectspace_view_vector = mul( inv_view_matrix, eye_position ) - vsInStruct.position;
   vsOutStruct.tangenteye =  mul( tangentspace_matrix, objectspace_view_vector );

   vsOutStruct.half_angle = vsOutStruct.tangentlight + vsOutStruct.tangenteye;

   return vsOutStruct;
}