[postgis-devel] [Barend.Gehrels at geodan.nl: [OSGeo-Discuss] Generic Geometry Library (ggl)]

Paul Ramsey pramsey at opengeo.org
Tue Feb 17 07:46:29 PST 2009


Uh huh? Have a look and see how much real code is in there, first.

P.

On Tue, Feb 17, 2009 at 6:16 AM, strk <strk at keybit.net> wrote:
> Sounds something that could really speed up topology ops...
>
> ----- Forwarded message from Barend Gehrels <Barend.Gehrels at geodan.nl> -----
>
> Date: Tue, 17 Feb 2009 14:11:33 +0100
> From: Barend Gehrels <Barend.Gehrels at geodan.nl>
> Organization: Geodan Holding b.v.
> Subject: [OSGeo-Discuss] Generic Geometry Library (ggl)
> Reply-To: OSGeo Discussions <discuss at lists.osgeo.org>
> To: OSGeo Discussions <discuss at lists.osgeo.org>
> X-BeenThere: discuss at lists.osgeo.org
>
> Dear list,
>
> It is a pleasure for us to announce the Generic Geometry Library (ggl).
>
> It is an Open Source library, written in C++. The library is template
> based, and generic. With generic we mean that the algorithms work not
> only with the provided geometries, but also with geometries that are
> defined by the library user, such as legacy points, custom linestrings, etc.
>
> Because of this the library is following OGC conventions loosely, not
> strictly. All algorithms are implemented as standalone functions,
> instead of methods on geometries. Nevertheless, OGC conventions, names
> and meanings are followed as much as possible. Not all OGC algorithms
> are already implemented. On the other hand the library offers other
> things such as distance calculations over the globe.
>
> So it is a library modelled as the C++ std:: library and as most Boost
> libraries are. The library is proposed to Boost (Boost is a well-known
> peer reviewed C++ Library Collection). It is following the Boost
> Software License, which is a permissive Open Source License.
>
> The library is accessible via SVN at Boost:
> https://svn.boost.org/svn/boost/sandbox/ggl but can also be downloaded
> from http://geometrylibrary.geodan.nl. Much documentation and many
> examples can be found there. Note for example the Custom Linestring
> example showing things which cannot so easily be done with non-template
> libraries.
>
> The library contains projections from PROJ4, converted to C++ . We first
> wanted to include PROJ4 as an example, like we did with ShapeLib and GD.
> However, we concluded that they fit better being implemented as C++
> templates, so they are automatically converted (it is reproducable).
> Like there is a PROJ4 Javascript branch, this might be considered as a
> PROJ4 C++ branch. We like your opinion about this.
>
> The library is in "preview 4", it has been submitted as preview to Boost
> three times, last year. Based on many comments the library has been
> enhanced. We think it is now in a proper shape to be used, and that
> algorithms can now be added without that everything is restructured again.
>
> The performance of the library is compared with other C++ OS GIS
> libraries and we measured that the library seems to be much faster than
> most of them, caused by the template approach.
>
> We welcome any type of comment, opinion or cooperation.
>
> Barend Gehrels, Geodan, Amsterdam, the Netherlands
> Bruno Lalande, Paris
>
>
>
> _______________________________________________
> Discuss mailing list
> Discuss at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/discuss
>
> ----- End forwarded message -----
>
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