Hi WanMil, Thanks so much for the fix. I have tried it so far on 2 style files and it works great. I can now also run the splitter overlap very high to allow for long distances between nodes and it still works. I even tried 50000 and it works. It even fixed the mutltiple border names. Normally it is so easy to find an error, so far I haven't yet found an error. Regards, Markus_g -----Original Message----- From: mkgmap-dev-bounces@lists.mkgmap.org.uk [mailto:mkgmap-dev-bounces@lists.mkgmap.org.uk] On Behalf Of WanMil Sent: Wednesday, 15 September 2010 6:11 AM To: Development list for mkgmap Subject: Re: [mkgmap-dev] Proposal: Multipolygon handling andline based multipolygons
That sounds like a good proposal. Another, possibly conceptually-related problem with the mp code is as follows: Consider a multipolygon with one outer way having the tags barrier=fence landuse=farm and one inner way having the tag natural=water
The mp splits this into two outer polygons with landuse=farm and barrier=fence and one inner polygon with natural=water. The problem is that now the fence no longer follows the (outer) ways it was originally designed to follow, but also follows the synthetic orthogonal ways created by the mp code. If the style rules process both landuse=farm (in the polygon ruleset) and barrier=fence (in the lines ruleset) then you get an unwanted, synthetic fence being created where none really exists.
Yes, that's a nice side effect of the patch I posted. Although strictly speaking the tagging of your example is wrong. If a member way should have non polygon related tags the multipolygon must be tagged instead of the members. So the mp should have landuse=farm and the outer way should be tagged with barrier=fence. This already works without the patch. But I know that lots of such taggings exist in the OSM data.
Having the mp code add a new tag to synthetic ways created as part of multipolygon splitting would be one way of tackling this problem (by subsequent re-writing of the style rules). The other would be to avoid adding barrier=fence (or other such linear tags) to synthetic ways created as part of polygon splitting.
Good news: you don't need to rewrite your style rules. This is done automatically by the patch. Could you please test the patch and give some feedback? Thanks! WanMil _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev