Even Rouault-2 wrote > You could possibly use the ST_ForceLHR() function of spatialite (through > the SQL SQLite > dialect) to post process your result: > http://www.gaia-gis.it/gaia-sins/spatialite-sql-4.2.0.html
Interesting, that ST_ForceLHR in Spatialite gives the same result than ST_ForceRHR in PostGIS. Description for Spatialite: Any Polygon Ring will be oriented accordingly to Left Hand Rule (Exterior Ring will be clockwise oriented, and Interior Rings will be counter-clockwise oriented). Description for PostGIS: Forces the orientation of the vertices in a polygon to follow a Right-Hand-Rule, in which the area that is bounded by the polygon is to the right of the boundary. In particular, the exterior ring is orientated in a clockwise direction and the interior rings in a counter-clockwise direction. This function is a synonym for ST_ForcePolygonCW Perhaps the rule of thumb would be not to talk just about right hand/left hand rules in GIS because they are ambiguous, but mention also what it really means like in the descriptions above, or in the GeoJSON specification: A linear ring MUST follow the right-hand rule with respect to the area it bounds, i.e., exterior rings are counterclockwise, and holes are clockwise. -Jukka Rahkonen- -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html _______________________________________________ gdal-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/gdal-dev
