intersect in region%

Sets the region to the intersection of itself with the given region.

This region's DC and given region's DC must be the same.

The result is always reliable for unsmoothed and smoothed drawing. For smoothed drawing, an intersect corresponds to clipping with this region's path, and then clipping with the given region's path. Further combining sends to this region correspond to combination with the original path before initial clip, and further combination with this region as an argument correspond to a combination with the given path after the initial clip. Thus, an intersecting region is a poor input for union, subtract, or xor, but it intersects properly in further calls to intersect.

• (send a-region intersect rgn) -> void
     rgn : region% object