[gdal-dev] Best vector driver?

Even Rouault even.rouault at spatialys.com
Thu Feb 16 09:13:34 PST 2017

On jeudi 16 février 2017 08:44:22 CET Kurt Schwehr wrote:
> Even,
> If a format can have a combination of point, lines, and polygons in a
> layer, should the layer class set wkbGeometryCollection? 

No it shoud return wkbUnknown.

wkbGeometryCollection is for geometries whose WKT is like

> And if so, does
> that imply Z is okay or not okay?

There's some ambiguity around this. It might be prudent to declare
wkbUnknown | wkb25DBit if 3D geometries might be returned.

> I see there is
> also wkbGeometryCollectionM and wkbGeometryCollectionZM, but
> no wkbGeometryCollectionZ.  And I see wkbGeometryCollection25D is old and
> shouldn't be used, yes?

wkbGeometryCollection25D can be used as wkbGeometryCollectionZ (when that makes 
sense). It is just that for compatibility reasons we have not renamed the constant and 
changed its value to be conformant to the ISO values.


Spatialys - Geospatial professional services
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