> But we need to agree on what is valid and what is > treated as invalid.
I think this is the first step we should start with (or at least define it somewhere with words while building test cases). Test cases are good technical tools to automatically evaluate algorithms and their multi-polygon compliance, but we should define, for the mappers, what is invalid and valid. What we have here : http://wiki.openstreetmap.org/wiki/Multipolygon is : "Generally, the multipolygon relation can be used to build multipolygons in compliance with the OGC Simple Feature standard (http://www.opengeospatial.org/standards/sfs). Anything that is not a valid multipolygon according to this standard (e.g., polygons with intersecting rings) should also be considered an invalid multipolygon relation, with the notable exception of touching inner rings (see below). " But I raised concerns about the exact meaning of this sentence here : http://lists.openstreetmap.org/pipermail/dev/2012-May/024948.html -- sly (sylvain letuffe) _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
