Doesn't the way you are defining the window mean that the client area is actually 401x301.
200 + 200 and the centre point at 0,0
150 + 150 and the centre point at 0,0
Unless I misunderstand what glOrtho is doing..
200 + 200 and the centre point at 0,0
150 + 150 and the centre point at 0,0
Unless I misunderstand what glOrtho is doing..