Signature
Parameters
Variables | Description |
---|---|
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.
See Also
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/
.