[Qgis-developer] QGIS and Geos version

[Andrea Peri 2007]

>Hi Andrea,
>
>On Tue, 21. Sep 2010 at 18:49:20 +0200, Andrea Peri 2007 wrote:
>>/  There is some incompatibility with a more recent version like the Geos
/>>/  3.2.2 version ?
/>
>No(t that I know).  OSGeo4W simply has 3.0 and updating probably would mean
>rebuilding a bunch of stuff.
>
>
>Jürgen

Ok.

Actually there is a bit of difference versions.
because
Postgis 1.5.1 use the 3.2.0 version.
Spatialite 2.4 use the Geos 3.2.2.

This has some results on the precision of the results.
Because a more recent version of geos has more fixed bugs.

So I think if a plugin on qgis use geos available with python it will be affect from all the bugs
presents to Geos 3.0.3 level.
for example this bug was resolved in the 3.1 version of geos.
http://trac.osgeo.org/geos/ticket/275

This is not a little question because to use a qgis plugin to do a Union or a Clip instead of postgis or spatialite
can give different results on different problems.

Another exaple was on a plugin we are developing.
It will use the WKT of a geometry, but the WKT developed in qgis will have some little difference from the WKT generate from postgis.

So I'm thinking perhaps is possible to compile only the dll and substitute the dll to the actual dll of geos used from qgis.
Don't ?

Thx,

Andrea Peri.