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

Fri Feb 12 18:30:10 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.
>
>

Minko,

the connecting lines are generated by the multipolygon code of mkgmap. 
It must divide each outer polygon into two halfs to cut out an inner 
polygon because we don't know a multipolygon type which is supported by 
the Garmins. We only know garmins single polygon type.

So what you see are the cutting lines created by the mkgmap multipolygon 
code.

WanMil