[geos-devel] How to build a multipolygon from a list of rings?

strk strk at keybit.net
Fri Oct 9 03:14:33 EDT 2009

Consider looking at shp2pgsql.c from PostGIS project.
It does contain code to build SFS geometries out of a set of rings.


On Fri, Oct 09, 2009 at 02:51:55PM +0800, zhuliangxiong at hotmail.com wrote:
> Hi there,
> I have a list of rings which are read from shapefile.  all out rings are clockwise and all hole rings are counterclockwise. After  reading  the OGC spec, it seems that i have to decide for each hole ring that to which out ring it belongs. Which means i have to build a list of Polygon first and then build a MultiPolygon. 
> how could i build a MultiPolygon from a list of rings  directly? It is hard for me to find out the relationship of holes and out rings.
> Regards,
> Abe Zhu
> _______________________________________________
> geos-devel mailing list
> geos-devel at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/geos-devel


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