[mkgmap-dev] [PATCH v2] - handle "anti-islands"

Tue Jan 26 21:07:28 GMT 2010

Hi Mark,

On Tue, Jan 26, 2010 at 05:51:07PM +0000, Mark Burton wrote:
> 
> v2 - now checks to see if an anti-island is surrounded by water or land.
> 
> If surrounded by water, it is converted back into an island (tagged
> with the land tag) and a warning message is issued.
> 
> Tested with the GB map, it detected a handful of anti-islands that
> should have been islands but their points were in the wrong order
> (backwards).

I tested with the FI map, but did not get any anti-island warnings.
I tested both without and with --generate-sea=polygons.  Sorry,
I did not run --generate-sea=polygons without your patch.  With
generate-sea, I found some anti-treasure like the following.

2010/01/26 22:41:52 WARNING (Osm5XmlHandler):   Way null (http://www.openstreetmap.org/browse/way/4611686018427399860) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=62.22656&mlon=25.82736&zoom=17) but they can't be merged because both are boundary nodes!

This looks like a generated way (bogus browse URL) and a generated node
at a tile boundary, lat=62.226562.  The generated node is very close to
a real coastline node.  Can you avoid adding a node when it is "Garmin equal"
to an existing node?  There are many lakes (tagged as natural=coastline)
at my tile boundaries.

2010/01/26 22:41:47 WARNING (Osm5XmlHandler): Non-closed coastline segment does not hit bounding box: 28953387 (60,51214/27,91898) 28953375 (60,50997/27,91529) http://www.openstreetmap.org/?mlat=60.51214&mlon=27.91898&zoom=17

This ought to be at the Geofabrik finland.osm.bz2 boundary, i.e.,
nothing to worry about, for now.  The coastline segment belongs
to Russia since WW II.

Best regards,

	Marko