Hi, Just wondering if this behavior is expected. I was confused why OGR_G_GetGeometryRef() on a ring of a polygon could not be exported to WKB. The reference to the ring reports as being a wkbLineString but has WkbSize() of zero since it is really a wkbLinearRing. I would expect GetGeometryType() to return 101 in that case.
If the reference is forced to a Polygon, the returned geometry has non-zero WkbSize() and can be exported to WKB as expected. However, if the reference is forced to LineString, the returned geometry reports as wkbLineString but has WkbSize() of zero since it is still a LinearRing. # GDAL 3.11.3, GEOS 3.12.2 from osgeo import ogr wkt = "POLYGON((2 49,3 49,3 48,2 49))" g = ogr.CreateGeometryFromWkt(wkt) # ref to ring of the polygon g2 = g.GetGeometryRef(0) g2.GetGeometryType() # 2 g2.WkbSize() # 0 g2.ExportToWkt() # 'LINEARRING (2 49,3 49,3 48,2 49)' # ref to ring forced to wkbPolygon g3 = ogr.ForceTo(g2, ogr.wkbPolygon) g3.GetGeometryType() # 3 g3.WkbSize() # 77 g3.ExportToWkt() # 'POLYGON ((2 49,3 49,3 48,2 49))' # ref to ring forced to wkbLineSTring g4 = ogr.ForceTo(g2, ogr.wkbLineString) g4.GetGeometryType() # 2 g4.WkbSize() # 0 g4.ExportToWkt() # 'LINEARRING (2 49,3 49,3 48,2 49)' Thanks. Chris _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
