Hi, I've started adding tests for OverlayOp [1] and I noticed curious results for basic test case.
OverlayOp(UNION) on Four segments of a sqare always construct a MultiLineString. I'd have expected a polygon, shouldn't I? In this case, I noticed OverlayOp always labels edges as UNDEF or BOUNDARY this simply leads to non-area results and the PolygonBuilder never receives any input which qualifies as a polygon. As you can see in the test, the union is constructed incrementally: GeometryPtr lines12(line1->Union(line2.get())); GeometryPtr lines123(lines12->Union(line3.get())); GeometryPtr lines1234(lines123->Union(line4.get())); but the same result (MultiLineString) is returned if I union via UnaryUnion on MultiLineString or GeometryCollection. My questions are: 1. Is this expected behaviour? 2. Am I missing any trick to actually obtain the polygon? [1] https://trac.osgeo.org/geos/changeset/4153 Best regards, -- Mateusz Ĺoskot, http://mateusz.loskot.net _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel
