[geos-devel] Small gaps between results of GEOSDifference?

Sandro Santilli strk at keybit.net
Fri Feb 15 09:29:18 PST 2013

On Fri, Feb 15, 2013 at 05:33:53PM +0100, Marco Hugentobler wrote:
> Hi Sandro
> Thanks for explaining this. In the short term, it seems best to me
> to always enable 'topological editing' in QGIS together with avoid
> intersection. That way, the intersection vertices are added to both
> geometries.

Speaking of which, I was looking for a way to programmatically enable
'topological editing' while editing "TopoGeometry" layers in qgis.
If you can help there I'm all ears :)

> >Exposing fixed precision to the C-API is on the TODO list for 3.1 so if
> >you want to help with that you're very welcome. It will take exposing
> >a new PrecisionModel abstract class and provide means to attach them to
> >GEOSGeometry objects.
> So basically the subclass of PrecisionModel will do the rounding?

That's what it should theoretically happen. Noding will be performed
based on the given precision grid so the segment and the vertex will
be found to be "intersecting" and consequently noded when building
the second topology.

> Looks like a very clean approach to me, I'm looking forward to the
> new version.

Will be a long way.


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