
         var vertices = new Float32Array(
            [
               -1, 1*aspect, 1, 1*aspect, 1, -1*aspect,
               -1, 1*aspect, 1, -1*aspect, -1, -1*aspect
            ]);
         
         var vbuffer = gl.createBuffer();
         gl.bindBuffer(gl.ARRAY_BUFFER, vbuffer);
         gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
         
         var triCount = 2,
             numItems = vertices.length / triCount;
         
         gl.useProgram(program);
         
