Did we ever get a GSIP for this curve work? I went looking for something to
link to from the release announcement and could not find anything.
I also could not find the documentation in the docs:
http://docs.geoserver.org/latest/en/user/webadmin/data/layers.html#layer-types
Jody Garnett
On Thu, Jul 17, 2014 at 11:23 AM, Andrea Aime <[email protected]>
wrote:
> Hi,
> finally made it to make a patch for proper arc support in GeoServer:
> https://github.com/aaime/geoserver
>
> The user visible changes are that you get two new elements in the GUI to
> configure the curves:
> 1) a flag that the admin will use to indicate wether the linework can
> contain also circular arcs
> 2) a linearization tolerance, as a measure (e.g., you can specifiy 2m or
> 3ft)
>
> 2) is kind of obvious, 1) is the byproduct of GeoServer using GML3
> deprecated types for single
> and multiple lines, LineStringType and MultiLineStringType, which cannot
> contain curves.
> The issue happens in the FeatureTypeSchemaBuilder, where we basically
> force the properties
> to be LineString or MultiLineString without knowing if they will contain
> curves, or not.
>
> The issue is, from the software we cannot know if there will be curves,
> we'd have to make a full scan of all the data
> every time we build those schemas, as lines are just lines, the fact that
> they might contain circular
> segments is a detail that the data source will not give you, because there
> is not line layer
> that is made purely of curves, they are always mixed with straight ones.
>
> So... in order to maintain backwards compatibility in WFS 1.1 output, I
> had to ask the admin to tell
> me whether there will be curves, and in that case, we switch from
> LineString to Curve, from
> MultiLineString to MultiCurve, without affecting the current 99% case,
> where curves are not present.
> GML 3.2 output is instead unaffected, because it uses Curve and MultiCurve
> for everything already.
>
> The way the switch is done is a bit hacky, basically the feature type is
> transformed, for the sole
> sake of computing the GML schema, so that it uses CurveGeometry as the
> binding for the
> data (as said, it does not make sense to do that in general, as we can
> also get LineString
> in the data mix, plus, CurveGeometry is an interface, thus it cannot be a
> Geometry, which
> is instead a class).
>
> Basically, I've tried to keep this new curve support as much out of the
> way as possible from
> the normal usage, while still making it possible to support curves for
> those that have them.
>
> Feedback welcomed
>
> Cheers
> Andrea
>
> --
> ==
> GeoServer Professional Services from the experts! Visit
> http://goo.gl/NWWaa2 for more information.
> ==
>
> Ing. Andrea Aime
> @geowolf
> Technical Lead
>
> GeoSolutions S.A.S.
> Via Poggio alle Viti 1187
> 55054 Massarosa (LU)
> Italy
> phone: +39 0584 962313
> fax: +39 0584 1660272
> mob: +39 339 8844549
>
> http://www.geo-solutions.it
> http://twitter.com/geosolutions_it
>
> -------------------------------------------------------
>
>
> ------------------------------------------------------------------------------
> Want fast and easy access to all the code in your enterprise? Index and
> search up to 200,000 lines of code with a free copy of Black Duck
> Code Sight - the same software that powers the world's largest code
> search on Ohloh, the Black Duck Open Hub! Try it now.
> http://p.sf.net/sfu/bds
> _______________________________________________
> Geoserver-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/geoserver-devel
>
>
------------------------------------------------------------------------------
Want fast and easy access to all the code in your enterprise? Index and
search up to 200,000 lines of code with a free copy of Black Duck
Code Sight - the same software that powers the world's largest code
search on Ohloh, the Black Duck Open Hub! Try it now.
http://p.sf.net/sfu/bds
_______________________________________________
Geoserver-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/geoserver-devel
