[geos-devel] Re: (not) Empty geometry (Jo)

[Mateusz Loskot]

Jo wrote:
> Hi,
> The attach was only the wkt definition of the polygon...
> Things are gettin a bit clearer now: the polygon is also valid and
> empty on OGR (so I guess no prob in importing it to geos).
> I think is outside the scope of this mailing list to tell how Im
> importing it into OGR, but I ll do it anyway :-)
> 
> 
> 		while( (poFeature = poLayer->GetNextFeature()) != NULL )
> 		{
> 			OGRGeometry *poGeometry;
> 			poGeometry = poFeature->GetGeometryRef();
> 	
> 			if( poGeometry != NULL && wkbFlatten(poGeometry->getGeometryType())
> == wkbPolygon )
> 			{
> 				OGRPolygon *poPolygon = (OGRPolygon*) poGeometry;
>                                  DoStuffWithGEOS()

What does this return?

poPolygon->getExteriorRing()->getNumPoints()

> 			}
>                    }
> Inside DoStuffWithGEOS(), I export it to text and import it (from
> text) to Geos. 

You don't need to go through text export/import.
Just dump OGR geometry as GEOS geometry using
OGRGeometry::exportToGEOS() method:

http://trac.osgeo.org/gdal/browser/trunk/gdal/ogr/ogr_geometry.h#L118

And check if GEOS geomtetry is OK now.

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net
Charter Member of OSGeo, http://osgeo.org