[mkgmap-dev] Broken coastline errors between V1188 and V1398

Fri Nov 20 07:35:13 GMT 2009

Chris-Hein Lunkhusen schrieb:
> Michael.TheBlackCat schrieb:
> 
>> i recognized  broken coastline errors between the mkgmap verion 1188 and
>> 1398. Please refer to the appended  jpegs (my coastline is a little bit
>> thicker ti identify the sea area).
> 
> Hi Michael,
> I can confirm that this problem exists in the newer versions of mkgmap.
> Some coastlines are missing in the map.
> 
> Dunno if this has something to do with the changes in the multipolygon
> code.

After playing a little bit with the data, I think it is the
MP code thats causing the coastline to disappear.

It seems that the error occurs, when a coastline is member
of to many boundary-multipolygons. In my test the coastline
was disappearing when beeing member of more than two
boundary-MPs.

So as a workaround: I think for boundary-multipolygons the
multi-MP handling is not neccecary at all, because
boundaries (normally) are rendered as lines and not as
areas.

Chris