[OSM-dev] Algorithm help
richard at systemeD.net
Thu May 29 02:12:52 BST 2008
Thanks Richard and Nathan for the pointers - really appreciated. I
think I've got it now.
Nathan Vander Wilt wrote:
> That said, I'm guessing there are other assumptions being made
> within OSM that break down under spherical geometry. If your polygon
> doesn't contain pole(s) or cross the +/-180 degree meridian,
> checking the winding could be handled by a cartesian algorithm.
Yep - it's so that Potlatch can show the direction of a closed way;
happily Potlatch works with projected co-ordinates anyway and is
(happily) unlikely to have to load a way greater than a hemisphere. :)
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