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

[zhuliangxiong at hotmail.com]

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
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