Hi all,

I think that the bounding polygon given with option --dem-poly should be also be used in the precomp-sea option,
so that mkgmap doesn't generate sea polygons outside of the bounding polygon. With the current code a map of e.g.
scandinavia looks strange, see attached picture.

In a further step I should try to use that polygon also for the background polygon (0x4B) and other data.
In a final step we might be able to use it for routing data so that you can split maps at left-driving / right-driving boundaries,
but that needs more thinking.

I've not coded anything yet, but I wonder if the option should be changed from dem-poly to e.g. --polygon-file or --bounding-polygon.

Gerd