[mkgmap-dev] [PATCH v5] sea polygons

Wed Aug 26 10:59:25 BST 2009

dear christian,

On 09-08-26 10:37:12 CEST, Christian Gawron wrote:
> I also get similar problems for some tiles (the result may depend on the 
> splitter parameters).
> The problem is that there are several shoreline segments that do not end 
> at the map boundary. Two examples are:
> - Rügen: The shoreline ends at the border to Poland. The current patch 
> closes this segment since it's "nearly closed" (the distance between 
> start and end is less than 0.1 * segment-length). This should result in 
> the Polish part of the island (Swinoujscie) beeing flooded. This seems 
> to be the best the algorithm can do since he doesn't know the Polish 
> part of the shoreline cut off by osmosis.

i guess you mean usedom here, as rügen does not border poland.

usedom is fine in my result with mkgmap1144+sea5, using the bbox cut out
of the planet, which supports your argument, i guess.

> If anyone has a good idea how to handle an incomplete shoreline, please 
> let me know. Right know, it might be best to do the following:
> - get a country extract like germany.osm.bz2 from geofabrik,
> - calculate the boundary box,
> - use xapi or same other source to get the complete shoreline in this 
> boundary box,
> - mix in the shoreline using osmosis,
> - use the result as input for splitter and mkgmap.

or take the planet or europe and cut a bbox from it?

best,
rj