glutEntryFunc  -  sets  the mouse enter/leave callback for
the current window.

glutEntryFunc
	glutEntryFunc(func) -> None

void glutEntryFunc(void (*func)(int state));

func      The new entry callback function.

glutEntryFunc sets the mouse enter/leave callback for  the
current  window.  The  state  callback parameter is either
GLUT_LEFT  or  GLUT_ENTERED  depending  on  if  the  mouse
pointer has last left or entered the window.

Passing  NULL  to glutEntryFunc disables the generation of
the mouse enter/leave callback.

Some window systems may not generate accurate  enter/leave
callbacks.   X IMPLEMENTATION NOTES An X implementation of
GLUT should generate accurate enter/leave callbacks.

glutMotionFunc, glutCreateWindow

Mark J. Kilgard (mjk@nvidia.com)