Hi Nic and Scott, On 1 December 2010 14:27, Nic Roets <nro...@gmail.com> wrote: > http://trac.openstreetmap.org/browser/applications/rendering/gosmore/bboxSplit.cpp?rev=24484
A further comment on splitting a big dataset into areas is that if the areas are disjoint (like in the case of countries, provinces and other administrative areas) or nearly disjoint (like in the case of their bboxes) you can build a sort of look-up tree from the list of bboxes, so that with n bboxes you only need a little more than log n "is this node inside?" checks. So for example if you're splitting the planet into 20000 areas, you only need about 15 tests for every node by doing a sort of bisection search. I see that bboxSplit.cpp tests against every single bbox, I haven't looked at Scott's mkgmap code. Cheers _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
