On Wed, Mar 11, 2009 at 12:26 PM, Paul Ramsey <[email protected]> wrote: > There isn't a standard, but you can force your polygons into an > orientation with ST_ForceRHR, which forces a clockwise orientation for > exterior rings and anti-clockwise for interior rings. >
Thanks Paul, I did find that. Since there is no standard direction for simple polygons, I can use clockwise, secure in the knowledge that I'm not going against the grain. > P > > On Tue, Mar 10, 2009 at 3:20 PM, Rick <[email protected]> wrote: >> I'm fairly new to this. >> >> I have a requirement to do calculations on runways in aerodrome maps. >> I orient the runway centerlines west to east so that the low runway >> number is at the start of the line. >> >> I'm doing a similar, more complex normalization to the runway outline, >> the first vector crosses the start of the centerline. Whether they >> are clockwise or ccw doesn't matter to me as long as it is always the >> same. Is there a standard insidedness for polygons which would >> dictate a direction? >> >> -- >> Cheers! >> Rick. >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > -- Cheers! Rick _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
