XtAddExposureToRegion — merge Expose and GraphicsExpose events into a region.
Synopsis
void XtAddExposureToRegion(event, region)
XEvent ∗event;
Region region;
Arguments
eventSpecifies a pointer to the Expose or GraphicsExpose event.
regionSpecifies the region object (as defined in <X11/Xutil.h>).
Description
The XtAddExposureToRegion utility function merges Expose and GraphicsExpose events into a region that clients can process at once instead of processing individual rectangles.
XtAddExposureToRegion computes the union of the rectangle defined by the exposure event and the specified region. Then it stores the results back in region. The Intrinsics pass an XRegion to a widget in the XtExposure method.
If the event argument is not an Expose or GraphicsExpose event, XtAddExposureToRegion returns without an error and without modifying region.
This function is used by the Intrinsics exposure compression mechanism. It is not ordinarily used explicitly by widgets.
Structures
Region is a pointer to an opaque type.