InvertRect
InvertRect Invert all pixels enclosed by a rectangle
#include <Quickdraw.h> Quickdraw
void InvertRect(theRect );
Rect *theRect ; rectangle to invert
InvertRect inverts all pixels in the specified rectangle. All black pixels are
set to white and vice versa.
theRect is the address of an 8-byte Rect structure, in local coordinates.
Returns: none

Notes: For "old model" color, the output result of all Invertxxx functions
depends upon the device being used.
InvertRect doesn't change the pen position.
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.