On Thu, Jul 16, 2009 at 10:41 AM, Chris Browet<[email protected]> wrote: > 2009/7/16 Frederik Ramm <[email protected]> >> Chris Browet wrote: >>> >>> I'd be curious to know how the api calculates the bounding box of such a >>> relation >> >> >> http://wiki.openstreetmap.org/wiki/OSM_Protocol_Version_0.6#Bounding_box_computation >> >>> assuming the api definition is "the smallest bbox containg all >>> children bbox'es". >> >> It isn't. >> > > Ok. If I understand well, it adds to a relation bbox all the nodes and ways > of children relations (+ the "pure" ways and nodes, of course). > > That won't remove the problem of infinite recursion: R1 -> R2 -> R1; it will > add to R1 all ways/nodes of R2, which itself will add all ways/nodes of R1, > which will... > > Bottomline question is: How does the api handle the case?
short answer: it doesn't. long answer: the position taken by the API for both map calls and changeset bboxes is that relations don't have physical extent - only their node and way members do. bboxes are calculated only from the immediate members of the relation, so recursion is necessary. (there is a bug, which means something is recursing, but it's not supposed to) cheers, matt _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
