Finish
OpenGL rendering by external
OpenGL code into window 'windowPtr'. This is
the counterpart to
Screen('
BeginOpenGL'). Whenever you used
Screen('
BeginOpenGL') to enable external
OpenGL drawing from Matlab, you *must*
call
Screen('
EndOpenGL') when you're finished with a window, either because you
want to draw into a different window, or you want to use a
Screen command.
Psychtoolbox will abort your script if you omit this command.