[Tilesathome] Coastline loaded for latitude 60 and higher

[Martijn van Oosterhout]

On Sun, Nov 2, 2008 at 10:38 PM, Dirk-Lüder Kreie <osm-list at deelkar.net> wrote:
>> But land is supposed to be on the left side of the way. Keeping that in
>> mind
>> you should always know where land is.
>
> It's apparently not that easy to calculate, so yes, it *should* know where
> land is, but it is not easily done, especially if you have quite a few
> islands and/or "interestingly shaped" coastline. It of course becomes
> impossible if there is an error in one of the coastlines.

The coastline checker uses the orientation of the largest closed
completely contained polygon. Seems to work well and is trivial to
calculate. By definition it's not contained inside any other polygon
so there is no ambiguity.

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/