[geos-devel] Area building (was: Geometry/Rectangle Intersection: line touching rectangle)

[Sandro Santilli]

On Fri, Sep 12, 2014 at 12:36:30PM +0300, Mika Heiskanen wrote:
> On 09/12/2014 11:07 AM, Sandro Santilli wrote:

> >The final overlay (self-union) was needed to allow building an area
> >from a linework like this:
> >
> >  +---+---+
> >  |   |   |
> >  +---+---+
> >
> >It might indeed be useful to make the self-union optional for cases in
> >which it is known in advance that the above case would never happen.
> 
> That could provide a great speedup for complex geometries.

PostGIS topology would also not need the final overlay.
Changing this would require adding a new function signature to liblwgeom
(keeping old to retain backward compatibility) while at the SQL level
there could be just an override. Patch welcome ! :)

--strk;