glutShowOverlay,  glutHideOverlay  -  shows  or  hides the
overlay of the current window

glutHideOverlay
	glutHideOverlay() -> None
glutShowOverlay
	glutShowOverlay() -> None

void glutShowOverlay(void);
void glutHideOverlay(void);

glutShowOverlay shows the overlay of the  current  window;
glutHideOverlay  hides  the overlay. The effect of showing
or hiding an overlay takes place  immediately.  Note  that
glutShowOverlay  will  not  actually  display  the overlay
unless the window is also shown (and even a  shown  window
may  be  obscured  by other windows, thereby obscuring the
overlay). It is typically faster and less resource  inten-
sive  to  use these routines to control the display status
of an overlay as opposed to removing  and  re-establishing
the overlay.

glutEstablishOverlay, glutShowWindow

Mark J. Kilgard (mjk@nvidia.com)