FillRgn
FillRgn Fill region with specified pattern
#include <Quickdraw.h> Quickdraw
void FillRgn(theRgn, thePat );
RgnHandle theRgn ; handle of Region to fill
PatPtr thePat ; address of an 8-byte Pattern structure
FillRgn fills all pixels enclosed by a region with a specified pattern. The
transfer mode is patCopy, overwriting all bits within the region.
theRgn is the handle of a region.
thePat is the address of an 8-byte Pattern structure. It may be one of the
global patterns (black, white, gray, ltGray, or dkGray); or a pattern
read from a resource; or a pattern created by the application. See
PenPat for examples of obtaining or creating a pattern.
Returns: none

Notes: The pattern overwrites the interior of the region, including the output of
any previously- executed "frame" operation. As with all pattern operations,
the top-left of the pattern is aligned at a multiple of 8 dots from local
coordinate (0,0).
The pen position is not changed by this function. The GrafPort's pen
pattern, pen mode, and background pattern are ignored.
As with all Quickdraw drawing, the output is clipped to the intersection of
the current GrafPort's bitMap boundary rectangle, the port rectangle,
clipping region, and visible region.