[postgis-devel] Fixed precision for ST_Intersection, ST_Union, etc.
strk at keybit.net
Tue Mar 15 10:19:33 PDT 2016
On Tue, Mar 15, 2016 at 09:24:41AM -0400, Daniel Baston wrote:
> The relevant code is in GeometryPrecisionReducer.cpp, around line 72. It
> can be paraphrased as:
> geom_reduced = reduce_coordinate_precision(geom)
> if (!geom_reduced.isValid())
> geom_reduced = geom_reduced.buffer(0)
> return geom_reduced
Ouch, that's really bad indeed.
> The only change I can see making to GEOS is in the C API, renaming the
> existing GEOSGeom_setPrecision to GEOSGeom_reducePrecision, and adding a
> new GEOSGeom_setPrecision that does nothing more than set the
> PrecisionModel. The PostGIS overlays could then use the new
> GEOSGeom_setPrecision, while a PostGIS ST_ReducePrecision could use
Sounds good to me, 3.6.0 isn't out yet so changing the signature
is still possible.
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