[mkgmap-dev] Bizarre flooding in South Wales

Tue Oct 11 06:09:47 BST 2011

On Mon, Oct 10, 2011 at 11:44:07AM +0100, Steve Hosgood wrote:
>Last week I generated a routable map for South Wales which does 
>everything you'd expect concerning routing just fine, but suffers the 
>well-known "flooding" problem.

Coincidentally, someone reported a flooding problem in Finland as well.
I had not paid attention to it, because mkgmap did not complain. It
turned out that the reason was that almost a month ago, someone had added
an island to a natural=water lake not by adding it as a role=inner member
to the multipolygon relation, but by tagging it as natural=coastline. Because
this was the only natural=coastline in the map tile, everything was flooded
with sea water.

I was wondering if generate-sea could complain when a natural=coastline
(multi)polygon overlaps a natural=water (multi)polygon. I do understand
that it might not be too useful to complain about other cases of overlapping
areas, but I would guess that there is no valid case of having lakes in
sea areas.

Best regards,

	Marko

PS: Did you try to enable logging and grepping the log for coastline messages?
You can get my logging.properties at http://www.polkupyoraily.net/osm/. Invoke
mkgmap like this:
java -Dlog.config=logging.properties ... -jar mkgmap.jar ...
grep -i coast mkgmap.log.0