attribute vec3 vertex;
varying vec2 vTexCoord;

void main(void)
{   
   vec2 Pos = sign(vertex.xy);

   gl_Position = vec4(Pos.xy, 0, 1);

   vTexCoord.x = 0.5 * (1.0 + Pos.x);
   vTexCoord.y = 0.5 * (1.0 - Pos.y);


}
