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()
