Hi, The documentation for the geopoly module states that the vertices must be defined in a counter-clockwise order so that the interior of the polygon is on the left of the element as it is drawn.
However, I have discovered that a polygon transformed with geopoly_xform can result in a polygon having vertices reading clockwise. For instance, a polygon mirrored about either the x or y axis will produce this effect. The geopoly module allows these transformed polygons to be added to the table. If I then create an exact same polygon shape having counterclockwise order for the vertices and use the geopoly_overlap function to test it against the one with clockwise order I find the result = 4, meaning the polygons are regarded as identical. My question then is, is it really necessary to ensure a counterclockwise order when a polygon shape is entered for the first time in the table. regards, Graham _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
