Hi Jon, Jon Burgess wrote:
> This is one of the things which has to be done but is not really > documented. The algorithm osm2pgsql uses is to gather together all the > tags which are related to the polygon feature (e.g. landuse=, natural= > etc) and then compare those against the outer ways. If the way and > polygon match then it will exclude the way. If they do not match then > the way will be included. Ah right - otherwise the outer way will form a no-holes polygon, which is probably wrong..and if the holes don't have their own map rendering representation, the fill might show through. (Not to mention the interpretation would be wrong. :-) > In particular, there is some legacy data which has no tags on the > relation but identical tags on both the outer and inner ways . In this > case, the polygon needs to be rendered with the appropriate tags but > neither the inner nor outer ways are rendered. Oy...that data strikes me as really broken. :-( In particular, defining anything as having "same" or "different" tags strikes me as perilous because tags are sets of values...if one of a relation's ways has had additional data tagged onto it, is it now "different"? :-) (For example, someone tags the boundary of an island as a walking path...the island boundary is tagged as lake because it's the hole in the lake and someone wanted to tag everything...are we now different? Is the island now wet? :-) cheers bne -- Scenery Home Page: http://scenery.x-plane.com/ Scenery blog: http://xplanescenery.blogspot.com/ Plugin SDK: http://www.xsquawkbox.net/xpsdk/ X-Plane Wiki: http://wiki.x-plane.com/ Scenery mailing list: [email protected] Developer mailing list: [email protected] _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
