On 28 December 2011 07:48, Toby Murray <toby.mur...@gmail.com> wrote: > On Tue, Dec 27, 2011 at 12:38 PM, Stephan Knauss <o...@stephans-server.de> >> Thanks for the pointer to the styles. Any Idea how they determine which >> style to use for which geometry? >> I did not see anything that looks like a way to select the one style or the >> other based on the geographic location. >> >> Can you do the location check while rendering or would it be a preprocessing >> step during import? I did not see an additional "region" column so no idea >> how the selection was done. > > I thought this was the case but after a little searching, I came up > with proof. MapQuest added this feature to Mapnik: > http://lists.openstreetmap.org/pipermail/talk-us/2010-November/004820.html > > So it is apparently determined at render time. No clue how though :)
I don't know either but here is how I'd try to do this: at high zoom levels where it's unlikely that a single tile has to use multiple stylesheets you could run renderd with each stylesheet as a separate layer and select the right layer at mod_tile level, I think this could be really fast. At low zoom levels you could preprocess stylesheets to make a single big stylesheet with the sql queries having the polygon checks added to them. Cheers _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
