glXSwapBuffers(3G)	    OpenGL Reference - GLX	    glXSwapBuffers(3G)

NAME    [Toc]    [Back]

     glXSwapBuffers - exchange front and back buffers

C SPECIFICATION    [Toc]    [Back]

     void glXSwapBuffers( Display *dpy,
			  GLXDrawable drawable )

PARAMETERS    [Toc]    [Back]

     dpy       Specifies the connection	to the X server.

     drawable  Specifies the drawable whose buffers are	to be swapped.

DESCRIPTION    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     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     thread, and drawable identifies a window that is no longer	valid.







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glXSwapBuffers(3G)	    OpenGL Reference - GLX	    glXSwapBuffers(3G)



MACHINE	DEPENDENCIES
     Gang swap (multipipe synchronized buffer swaps) is	not supported on
     RealityEngine, RealityEngine2, and	VTX systems.  This will	be fixed in a
     future release.

     Before a window's buffers can be swapped, at least	one thread must	have
     attached an OpenGL	rendering context to the window	via glXMakeCurrent.

SEE ALSO    [Toc]    [Back]

     glXBindSwapBarrierSGIX, glFlush, glXJoinSwapGroupSGIX, glXSwapIntervalSGI


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