The glutCloseFunc function specifies the function
-that freeglut will call when a window is about to be closed,
-either because it is requested using glutDestroyWindow,
-because the user clicked on the "x" in the window header
-(for top-level windows only), or due to a pending closure of a
-subwindow's parent window. In the first case, the closure callback
+that freeglut will call to notify the application that a window
+is about to be closed, either because it is requested using
+glutDestroyWindow, because the user clicked on the "x" in the
+window header (for top-level windows only), or due to a pending closure
+of a subwindow's parent window. In the first case, the closure callback
is not invoked from the glutDestroyWindow call, but at a
-later time point.
+later time point.
Freeglut sets the current window to the window
-which is about to be closed when the callback is invoked.
+which is about to be closed when the callback is invoked. The window can
+thus be retrieved in the callback using glutGetWindow.
Please note that other further developments of GLUT provide a
glutWMCloseFunc. For compatibility, FreeGLUT also
provides this function. It is however an alias to
-glutCloseFunc.
+glutCloseFunc. Users looking to prevent FreeGLUT from
+exiting when a window is closed, as was made possible with
+glutWMCloseFunc by that callback's designer should look into
+using glutSetOption to set GLUT_ACTION_ON_WINDOW_CLOSE to
+GLUT_ACTION_GLUTMAINLOOP_RETURNS or
+GLUT_ACTION_CONTINUE_EXECUTION. This will prevent the
+application from exiting when a window is closed.
Changes From GLUT