glutUseLayer  -  changes  the layer in use for the current
window.

glutUseLayer
	glutUseLayer(layer) -> None

void glutUseLayer(GLenum layer);

layer     Either GLUT_NORMAL  or  GLUT_OVERLAY,  selecting
          the normal plane or overlay respectively.

glutUseLayer  changes  the per-window layer in use for the
current window, selecting either the normal plane or over-
lay.  The  overlay  should only be specified if an overlay
exists, however windows without an overlay may still  call
glutUseLayer(GLUT_NORMAL).  OpenGL commands for the window
are directed to the current layer in use.

To query the layer in use for a  window,  call  glutLayer-
Get(GLUT_LAYER_IN_USE).

glutEstablishOverlay, glutSetWindow

Mark J. Kilgard (mjk@nvidia.com)