 position2.set(temp, i);
  }  
}
verts.position1 = position1;
verts.position2 = position2;

// calls gl.createBuffer, gl.bindBuffer, gl.bufferData for each of
// position, normals, texcoord, indices of a sphere.
const bufferInfo = twgl.createBufferInfoFromArrays(gl, verts);

function render(time) {
  twgl.resizeCanvasToDisplaySize(gl.canvas);
  gl.enable(gl.DEPTH_TEST);

  gl.viewport(0, 0, gl.canvas.width, gl.canvas.height);

  // calls gl.bindBuffer, gl.enableVertexAttribArray, gl.vertexAttribPointer for 