struct VS_INPUT
   {
      float4 Position  : POSITION0;
      float2 TexCoord  : TEXCOORD0;
      float4 Color     : TEXCOORD1;
   };
   struct VS_OUTPUT
   {
      float4 Position  : POSITION0;
      float4 Color     : COLOR0;
      float2 TexCoord  : TEXCOORD0;
   };
   
   float4x4 projview_matrix;
   
   VS_OUTPUT vs_main(VS_INPUT Input)
   {
      VS_OUTPUT Output;
      Output.Position = mul(Input.Position, projview_matrix);
      Output.Color = Input.Color;
      Output.TexCoord = Input.TexCoord;
      return Output;
   }