EmptyRgn
returns Is theRgn empty?
EmptyRgn returns an indication of whether a region is empty. theRgn is the handle of a region, in local or global coordinates.
Returns: a Boolean value indicating whether the region is empty. It is one of: FALSE Not empty, encloses at least one pixel
Notes: Use this after performing region calculations. For instance:
SectRgn( srcRgnA, srcRgnB, destRgn ); .
. ... no intersection ...
.
}
This is also useful after InsetRgn to see if the region has been shrunk infinitely small. Or, you might use this to check up on GrafPort structure fields such as visRgn or clipRgn.