Or just use GLGRaphics() by itself.
Also I seem to remember that the "unable to calculate texture size" error has something to do with the screen not being opened or not being supported by your hardware, more than anything whatsoever actually to do with textures.
Also I seem to remember that the "unable to calculate texture size" error has something to do with the screen not being opened or not being supported by your hardware, more than anything whatsoever actually to do with textures.