SectRgn

Obtain the intersection of two regions

#include <Quickdraw.h> Quickdraw

void SectRgn(srcRgnA, srcRgnB, destRgn );

RgnHandle srcRgnA ; the two existing ...

RgnHandle srcRgnB ; ... source regions

RgnHandle destRgn ; handle of Region to hold result

SectRgn calculates the intersection of two regions (the area where they

overlap) and stores the result into a third region.

srcRgnA and . . .

srcRgnB are handles of existing regions in the current GrafPort.

destRgn is the handle of an existing region. Its current structure is

destroyed and it is given the structure defining the intersection of

srcRgnA and srcRgnB . It is OK if this parameter is the same as

either of the source regions.

Notes: The destRgn must already exist (see NewRgn). The intersection of

srcRgnA and srcRgnB is calculated, and the result is stored as destRgn :

srcRgnA srcRgnB destRgn

If the source regions do not intersect, or if either of them is empty,

destRgn is set to a region defined by the empty rectangle (0,0)(0,0). You

can test for this via EmptyRgn.

Referenced by (10):