[postgis-devel] LWgeom and PostGIS Java classes

[strk at refractions.net]

On Thu, Dec 16, 2004 at 01:57:41PM +0100, Markus Schaber wrote:
> Hi, Strk,
> 
> On Thu, 16 Dec 2004 13:26:38 +0100
> strk at refractions.net wrote:
> 
> > Actually since we "extend" we might as well add the SRID there...
> > If you want a 'pure' WKB you currently have to
> > 	SELECT asbinary(force_2d(geom))
> > to avoid ZM ...
> > Embedding a SRID would mean requiring to run
> > 	SELECT asbinary(dropBBOX(setSRID(force_2d(geom), -1)));
> > 
> > .. of course we might as well have asBinary(geom) *always* return
> > 'pure' WKB and rely on canonical (text or binary) forms for
> > postgis extensions .. (should keep discussing this on postgis-devel).
> 
> I think asBinary(geom) should always return pure WKB for OpenGIS
> compliant 2d geometries. Whether we silently drop additional,
> non-openGIS dimensions, or extend WKB, or raise an error or warnings,
> can be discussed. Any form of extended WKB from asBinary is subject to
> change as soon as the official WKB spec gets extended.
> 
> The canonical forms should be "lossless", as close to the internal rep
> as feasible (for efficiency reasons), provide all PostGIS features and
> extensions, and are subject to change between PostGIS releases.

If we don't want to loose "features" we'll have to provide a function
returning the "lossless" canonical binary form in a specific byte order.
This is for both byte order control and PG<74 support, where there were
no _send and _recv functions.

> > > I only hope that I don't get conflicts for the GEOS and ProJ versions (I
> > > would try to run current 1.0beta CVS branch additionally to 0.8.1
> > > currently running).
> > 
> > postgis 1.0beta should run with any GEOS version.
> > If you upgrade GEOS 0.8.1 will fail to work, but 0.9.1 should.
> 
> Currently, I'm forced to keep 0.8.1 working on my developer machine (as
> this is what we currently have to our production machines). We try to
> get an additional machine for this purpose, but delivery can need some
> time.
> 
> Maybe we manage to install both GEOS versions in parallel here, using
> different .so-names. If not, we need to compile postgis 1.0beta against
> old geos.

That should not be a problem as geos-1 and geos-2 *will* be installed with
different names.

--strk;

> 
> Thanks,
> Markus
> 
> -- 
> markus schaber | dipl. informatiker
> logi-track ag | rennweg 14-16 | ch 8001 zürich
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