Hi, I am investigating a better handling of different precision models within QGIS geometry operations, and in particular the "fixed" precision model.
Since geometry processing in QGIS relies mostly on GEOS, I think this is close to the kind of discussion that can be found in PostGIS: https://trac.osgeo.org/postgis/wiki/ToleranceDiscussion I see it as: - storing somewhere as a global parameter, the current precision model (in project parameters?), i.e. the current "grid" - adding a way to set the "global" precision model to the Geometry API - make the Geometry API use this precision model For the last point, I see two possibilities : - since we rely on the GEOS C API, which does not allow to modify the precision model (always the default - floating), it would require to add some new functions in the C API to change the precision model for coordinate constructions - using the C++ GEOS API instead of the C API that exposes precision models. I am not sure yet about what possibility to implement. Is there anything that prevent us from using the C++ GEOS API ? Having it in the C API may also benefit to other projects (PostGIS) ... Or am I totally missing other problems ? _______________________________________________ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer