glutVisibilityFunc(3GLUT) GLUT glutVisibilityFunc(3GLUT)

NAME
glutVisibilityFunc - sets the visibility callback for the
current window.

SYNTAX
void glutVisibilityFunc(void (*func)(int state));

ARGUMENTS
func The new visibility callback function.

DESCRIPTION
glutVisibilityFunc sets the visibility callback for the
current window. The visibility callback for a window is
called when the visibility of a window changes. The state
callback parameter is either GLUT_NOT_VISIBLE or
GLUT_VISIBLE depending on the current visibility of the
window. GLUT_VISIBLE does not distinguish a window being
totally versus partially visible. GLUT_NOT_VISIBLE means
no part of the window is visible, i.e., until the window’s
visibility changes, all further rendering to the window is
discarded.

GLUT considers a window visible if any pixel of the window
is visible or any pixel of any descendant window is visi-
ble on the screen.

Passing NULL to glutVisibilityFunc disables the generation
of the visibility callback.

If the visibility callback for a window is disabled and
later re-enabled, the visibility status of the window is
undefined; any change in window visibility will be
reported, that is if you disable a visibility callback and
re-enable the callback, you are guaranteed the next visi-
bility change will be reported.

SEE ALSO
glutCreateWindow, glutPopWindow

AUTHOR
Mark J. Kilgard (mjk@sgi.com)

GLUT 3.2 1