1991-2006
Silicon Graphics, Inc.
glXSwapBuffers
3G
glXSwapBuffers
exchange front and back buffers
C Specification
void glXSwapBuffers
Display * dpy
GLXDrawable drawable
Parameters
dpy
Specifies the connection to the X server.
drawable
Specifies the drawable whose buffers are to be swapped.
Description
glXSwapBuffers promotes the contents of the back buffer of drawable to become
the contents of the front buffer of drawable.
The contents of the back buffer then become undefined.
The update typically takes place during the vertical retrace of
the monitor,
rather than immediately after glXSwapBuffers is called.
glXSwapBuffers performs an implicit glFlush before it returns.
Subsequent OpenGL commands may be issued immediately after calling glXSwapBuffers,
but are not executed until the buffer exchange is completed.
If drawable was not created with respect to a double-buffered visual,
glXSwapBuffers has no effect,
and no error is generated.
Notes
The contents of the back buffer become undefined after
a swap. Note that this applies to pixel buffers as well as windows.
All GLX rendering contexts share the same notion of which are front buffers
and which are back buffers.
One consequence is that when multiple clients are rendering to the same
double-buffered window,
all of them should finish rendering before one of them issues the command
to swap buffers.
The clients are responsible for implementing this synchronization.
Typically this is accomplished by executing glFinish and then
using a semaphore in shared memory to rendezvous before swapping.
Errors
GLXBadDrawable is generated if drawable is not a valid GLX drawable.
GLXBadCurrentWindow is generated if dpy and drawable are
respectively the display and drawable associated with the current
context of the calling thread, and drawable identifies a window that
is no longer valid.
See Also
glFlush
Copyright
Copyright 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.