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



NAME
     glXSelectEventSGIX	- select GLX events for	a window or a GLX pixel	buffer


C SPECIFICATION
     void glXSelectEventSGIX( Display *dpy,
			      GLXDrawable drawable,
			      unsigned long mask )


PARAMETERS
     dpy       Specifies the connection	to the X server.

     drawable  Specifies a GLX drawable. Must be a GLX pixel buffer or a
	       window.

     mask      Specifies the events to returned	for drawable.


DESCRIPTION
     glXSelectEventSGIX	sets the GLX event mask	for a GLX pixel	buffer or a
     window. Calling glXSelectEventSGIX	overrides any previous event mask that
     was set by	the client for drawable. Note that it does not affect the
     event masks which other clients may have specified	for drawable since
     each client rendering to drawable has a separate event mask for it.

     Currently only one	GLX event, GLX_BUFFER_CLOBBER_MASK_SGIX, can be
     selected. The following data is returned to the client when a
     GLX_BUFFER_CLOBBER_MASK_SGIX event	occurs:

     typdef struct {
	 int event_type;       /* GLX_DAMAGED_SGIX or GLX_SAVED_SGIX */
	 int draw_type;	       /* GLX_WINDOW_SGIX or GLX_PBUFFER_SGIX */
	 unsigned long serial; /* # of last request processed by server	*/
	 Bool send_event;      /* true if this came for	SendEvent request */
	 Display *display;     /* display the event was	read from */
	 GLXDrawable drawable; /* i.d. of Drawable */
	 unsigned int mask;    /* mask indicating which	buffers	are affected*/
	 int x,	y;
	 int width, height;
	 int count;	       /* if nonzero, at least this many more */
     } GLXBufferClobberEventSGIX;

     A single X	server operation can cause several buffer clobber events to be
     sent. (e.g., a single GLX pixel buffer may	be damaged and cause multiple
     buffer clobber events to be generated). Each event	specifies one region
     of	the GLX	drawable that was affected by the X Server operation. The mask
     field indicates which color buffers and ancillary buffers were affected.
     All the buffer clobber events generated by	a single X server action are
     guaranteed	to be contiguous in the	event queue. The conditions under
     which this	event is generated and the event type varies, depending	on the
     type of the GLX drawable.



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



     For preserved GLX pixel buffers, a	buffer clobber event, with type
     GLX_SAVED_SGIX, is	generated whenever the contents	of the GLX pixel
     buffer is moved out of offscreen memory. The event(s) describes which
     portions of the GLX pixel buffer were affected. Clients who receive many
     buffer clobber events, referring to different save	actions, should
     consider freeing the GLX pixel buffer resource in order to	prevent	the
     system from thrashing due to insufficient resources.

     For an unpreserved	GLXPbuffer a buffer clobber event, with	type
     GLX_DAMAGED_SGIX, is generated whenever a portion of the GLX pixel	buffer
     becomes invalid. The client may wish to regenerate	the invalid portions
     of	the GLX	pixel buffer.

     For Windows, buffer clobber events, with type GLX_DAMAGED_SGIX or
     GLX_SAVED_SGIX, occur whenever an ancillary buffer, associated with the
     window, gets clobbered or moved out of offscreen memory. The event
     contains information indicating which color buffers and ancillary
     buffers--and which	portions of those buffers--were	affected.

NOTES
     glXSelectEventSGIX	is part	of the SGIX_pbuffer extension.


ERRORS
     GLXBadDrawable is generated if drawable is	not a valid window or a	valid
     GLX pixel buffer.


ASSOCIATED GETS
     glXGetSelectedEventSGIX



MACHINE	DEPENDENCIES
     The SGIX_pbuffer extension	is supported only on RealityEngine,
     RealityEngine2, and VTX systems, InfiniteReality systems and High Impact
     and Maximum Impact	systems.


SEE ALSO
     glXCreateGLXPbufferSGIX














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