SectRgnTo calculate the intersection of two regions, use the
PROCEDURE SectRgn (srcRgnA,srcRgnB,dstRgn: RgnHandle);
- A handle to the first of two regions whose intersection is to be determined.
- A handle to the second of two regions whose intersection is to be determined.
- A handle to the region to receive the intersection area.
SectRgnprocedure calculates the intersection of the two regions whose handles you pass in the
srcRgnBparameters, and it places the intersection in the region whose handle you pass in the
dstRgnparameter. If the regions do not intersect, or one of the regions is empty,
SectRgnsets the destination to the empty region defined by the rectangle (0,0,0,0).
SectRgnprocedure does not create a destination region; you must have already allocated memory for it by using the
The destination region may be one of the source regions, if desired.
SectRgnprocedure may temporarily use heap space that's twice the size of the two input regions.
SectRgnprocedure may move or purge memory blocks in the application heap. Your application should not call this procedure at interrupt time.