[postgis-users] WKT polygon and interior ring orientation

Kevin Neufeld kneufeld at refractions.net
Mon Nov 3 08:58:47 PST 2008

No, it looks like the PostGIS point-in-polygon shortcut uses Dan Sunday's algorithm, "Fast Winding Number Inclusion of a 
Point in a Polygon".


-- Kevin

Sufficool, Stanley wrote:
> Does ring orientation matter when you are calculating point in poly?
> When you calc a point in poly, do you take the sum of vertex angles from
> point to poly vertex and if sum of angles is >= 360 then point is in
> poly?

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