[mkgmap-dev] multipolygon with outer polygon within inner polygons

Fri Feb 12 18:13:45 GMT 2010

Thanks Steve,
So, as I understand it, I need to change the default relation style file
in order to convert those multipolygons into lines?

When I look at other osm maps from the same area (openmtbmap, radfahrers map, computerteddy)
I dont see those connecting lines between the borderlines.
Looking at their style files I don't see a difference in
how they handle the borders compared to the default style.
So... how do they do this, if they use exactly the same osm data?

If anybody who want to test it out, I put the osm data here:
http://moh.freehostia.com/osm/nassau.osm
(200kb, I only downloaded the border polygons of the municipality of
Baarle-Nassau). Or an even more simple example can be found
at http://moh.freehostia.com/osm/simple.osm (3kb)
The last one is not real osm data, but a simplification of the situation.

Steve Ratcliffe wrote:

Thanks for that image as it shows the problem clearly.

If the boundaries were being drawn as areas, then the lines would
not be seen (or not much anyway) since they would be zero width.
However since the borders are drawn as lines you clearly see the
connecting lines.

I think that the best way to solve this is for mkgmap to convert
to multipolygon into separate lines in the case of boundaries.

..Steve