hpux man page for xtaddexposuretoregion

XtAddExposureToRegion() 												   XtAddExposureToRegion()

XtAddExposureToRegion - merge Expose and GraphicsExpose events into a region.

Synopsis
  void XtAddExposureToRegion(event, region)
	 XEvent *event;
	 Region region;

Inputs
  event     Specifies a pointer to a Expose or GraphicsExpose event.

  region    Specifies a region to be added to.

Outputs
  region    Returns the specified region merged with the rectangle of the expose event.

Description
  XtAddExposureToRegion()  computes  the  union of the exposed rectangle specified by event and the region specified by region and stores the
  results back into region.  If the event argument is not an Expose or GraphicsExpose event, XtAddExposureToRegion() returns without an error
  and without modifying region.

Usage
  This	is  a  utility function that allows the caller to merge expose events into a region that can be processed all at once instead of as a
  series of individual rectangles.  It is used by the Intrinsics exposure compression mechanism, and could be of use within  event  handlers,
  action procedures, or a widget's expose() method.

Structures
  Region is a pointer to an opaque type.

See Also
  expose(4).

Xt - Event Handling													   XtAddExposureToRegion()