Hi, >> Can anyone point me to a good algorithm for selecting points within an >> arbitrary polygon?
> 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. I think I saw an XSLT implementation of that in one of the OSM projects somewhere but I tried very hard to forget ;-) Bye Frederik _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk