glutEnterGameMode(3GLUT) GLUT glutEnterGameMode(3GLUT)
NAME
glutEnterGameMode, glutLeaveGameMode - enters and leaves GLUT's game
mode.
SYNTAX
void glutEnterGameMode(void);
void glutLeaveGameMode(void);
DESCRIPTION
glutEnterGameMode is designed to enable high-performance fullscreen
GLUT rendering, possibly at a different screen display format. Calling
glutEnterGameMode creates a special fullscreen GLUT window (with its
own callbacks and OpenGL rendering context state). If the game mode
string describes a possible screen display format, GLUT also changes
the screen display format to the one described by the game mode string.
glutLeaveGameMode leaves the GLUT game mode and returns the screen dis-
play format to its default format.
When game mode is entered, certain GLUT functionality is disable to
facilitate high-performance fullscreen rendering. GLUT pop-up menus
are not available while in game mode. Other created windows and sub-
windows are not displayed in GLUT game mode. Game mode will also hide
all other applications running on the computer's display screen. The
intent of these restrictions is to eliminate window clipping issues,
permit screen display format changes, and permit fullscreen rendering
optimization such as page flipping for fullscreen buffer swaps.
After leaving game mode, the GLUT functionality disabled in game mode
is available again. The game mode window (and its OpenGL rendering
state) is destroyed when leaving game mode. Any windows and subwindows
created before entering the game mode are displayed in their previous
locations. The OpenGL state of normal GLUT windows and subwindows is
not disturbed by entering and/or leaving game mode.
The following GLUT routines are ignored in game mode: glutFullScreen,
glutSetWindowTitle, glutSetIconTitle, glutPositionWindow, glutRe-
shapeWindow, glutPopWindow, glutPushWindow, glutIconifyWindow, glut-
ShowWindow, glutHideWindow.
glutEnterGameMode can be called when already in game mode. This will
destroy the previous game mode window (including any OpenGL rendering
state) and create a new game mode window with a new OpenGL rendering
context. Also if glutEnterGameMode is called when already in game mode
and if the game mode string has changed and describes a possible screen
display format, the new screen display format takes effect. A reshape
callback is generated if the game mode window changes size due to a
screen display format change.
Re-entering game mode provides a mechanism for changing the screen dis-
play format while already in game mode. Note though that the game mode
window's OpenGL state is lost in this process and the application is
responsible for re-initializing the newly created game mode window
OpenGL state when re-entering game mode.
Game mode cannot be entered while pop-up menus are in use.
Note that the glutEnterGameMode and glutFullScreen routines operate
differently. glutFullScreen simply makes the current window match the
size of the screen. glutFullScreen does not change the screen display
format and does not disable any GLUT features such as pop-up menus;
glutFullScreen continues to operate in a "windowed" mode of operation.
glutEnterGameMode creates a new window style, possibly changes the
screen display mode, limits GLUT functionality, and hides other appli-
cations.
SEE ALSO
glutGameModeGet(3), glutGameModeString(3), glutInitDisplayString(3)
AUTHOR
Mark J. Kilgard (mjk@nvidia.com)
GLUT 3.7 glutEnterGameMode(3GLUT)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:39 CDT 2009