
void main(void)
{
   gl_Position = vec4( gl_Vertex.xy, 0.0, 1.0 );
   gl_Position = sign( gl_Position );
   
   gl_TexCoord[0].xy = (vec2( gl_Position.x, gl_Position.y ) + vec2( 1.0 ) ) / vec2( 2.0 ).xy;
 
}