On Wed, Apr 25, 2012 at 11:05 AM, Komяpa <[email protected]> wrote: > OSM does not have "area" object,
not yet (maybe in API0.7) > thus it needs something to mark > object as polygon. No. Most of the polygons do not require a tag "area" (amenity, building, landuse, leisure, landuse). > There are some tags that insist that a line/relation is filled inside. > These are area=yes and type=multipolygon. Sorry, I don't understand what you try to say here. "type=multipolygon" is about relations or I miss something ? > Sometimes context isn't clear. (Is a circular highway a > roundabout or a filled square?..) Agree. This case is why the tag area has been created. > It is rather distinct that highway=*, railway=* are linear usually, Hmm... "railway" yes, "platform" not sure. As many other features, platform can be represented by a node, a line or a polygon. This just depends on the contributor and his mapping level (and source accuracy and/or motivation). Same issue with people symbolizing rivers with a line and others with a polygon (and a centre line). > We either need a complete machine-readable list of tags that are > polygons or lines, or need to tag each object separately. For now I > see just the second approach being used; telling that is't invalid > without providing any reasonable fallback is a bad idea. > > Currently used list can be found at > http://svn.openstreetmap.org/applications/utils/export/osm2pgsql/default.style A closed loop tagged "highway" requires an additional information. Until a new element type "polygon" is created in the futur, the "area=yes" makes sens here. But a closed loop for "railway=platform" does not require any thing more than the geometry (a closed way tagged "railway=platform" is always a polygon. Are you asking contributors to specially tag an object just to avoid some work in osm2pgsql (detect if the way tagged "railway=platform" is closed or not) ? Pieren _______________________________________________ Tagging mailing list [email protected] http://lists.openstreetmap.org/listinfo/tagging
