Karl Newman wrote: > On Fri, Apr 11, 2008 at 5:47 AM, 80n <[EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>> wrote: > > You can have any shaped bbox you like as long as it is a rectangle ;) > > Can anyone point me to a good algorithm for selecting points > within an arbitrary polygon? > > 80n > > > I don't have it in pseudocode, but one I've heard of casts a ray > (horizontal is common) out from the point being tested and then checks > the intersection of that ray against each segment of the polygon. If > the total number of intersections is odd, then the point lies inside > the polygon. If the number is even, then it's outside. This works for > holes in a polygon, too. > > Karl http://en.wikipedia.org/wiki/Point_in_polygon
Igor -- http://igorbrejc.net _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk
