It should be applied only when the test IsValid fail. This should limit the slowness. Also pay attention that something the result of a MakeValid on an Invalid poligon could be a MultiPolygon or also a Collection. So to use it in an automatic manner need to apply also a ST_Multi(CollectionExtract(ST_MakeValid(geometry),3)). To be sure that it is always a geometry of the same kind.
A. 2014/1/16 Larry Shaffer <lar...@dakotacarto.com> > Hi Paolo, > > > On Wed, Jan 15, 2014 at 11:35 PM, Paolo Cavallini > <cavall...@faunalia.it>wrote: > >> Hi all. >> To the best of my knowledge, our make clean command, available through >> the Processing subplugin: >> >> http://plugins.qgis.org/plugins/processinglwgeomprovider/ >> >> is the most effective method to clean up invalid geometries. >> I would therefore suggest to include it in master, in order to have it >> available straight away for everybody. >> This depends on lwgeom, available at least on Debian and Windows. >> > > I have recently made a Homebrew formula for Mac that allows liblwgeom to > be built without Postgres/PostGIS installs (a bit of a hack, actually). So, > the standalone lib is now readily available on Mac OS X as well [0]. > > +1 for this to be included in QgsGeometry or similar class. > > It would help solve labeling issues where the extents-clipped geometry is > invalid. Would slow rendering down, of course, but would be good to have as > an option for faster machines and print jobs. Note: the validity fix would > be applied to the duplicates of feature geometries, which are used by PAL. > > [0] > https://github.com/Homebrew/homebrew/blob/master/Library/Formula/liblwgeom.rb > > Larry > > > > >> Opinions? Any blockers? >> >> All the best. >> -- >> Paolo Cavallini - www.faunalia.eu >> QGIS & PostGIS courses: http://www.faunalia.eu/training.html >> _______________________________________________ >> Qgis-developer mailing list >> Qgis-developer@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/qgis-developer >> > > > _______________________________________________ > Qgis-developer mailing list > Qgis-developer@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/qgis-developer > -- ----------------- Andrea Peri . . . . . . . . . qwerty àèìòù -----------------
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