[Qgis-developer] GEOS functions

[Carson Farmer]

Borys Jurgiel wrote:
> Saturday 31 January 2009 17:33:16 Andreas Neumann napisał(a):
>   
>> as far as I know this behavior was already with GEOS 2x. You have to 
>> deal with it. In case you get a geometry collection you can extract the 
>> part you are interested in. In case you are dealing with Polygons, 
>> extract the polygon part and skip/ignore the line and point part of the 
>> Geometry collection. Thats how I did it with some Postgis related work.
>>     
>
> I believe it's really important to have fTools working properly in QGIS 1.0.0, 
> so I would prefer to implement such stuff in fTools rather than wait for future 
> qgis releases... Even if it isn't optimal... :)
>   
Well none of the solutions we've come up with so far can really be 
implemented in fTools... but Martin had a suggestion from before, so 
I'll try this... essentially it involves intersecting, symmetrical 
differencing, then differencing again to get only polygon output... so 
I'll give this a go on problem geometries for now...

Carson