Re: [Flightgear-scenery] Testing for point/line in polygon problem

[Peter S. <psa...@gm...>]

Possibly more difficult to set up, but I'm adding more and more CGAL
routines to terragear.

I just commited a find points within bounding box which improved my lookup
times by 20%.

To find points within, what you really want is to create a CGAL
arrangement, then you can query a point and it should be really quick.

See
http://www.cgal.org/Manual/3.3/doc_html/cgal_manual/Arrangement_2/Chapter_main.html

Pete
On Dec 11, 2012 6:02 AM, "Adrian Musceac" <kan...@gm...> wrote:

> On Tuesday, December 11, 2012 11:03:41 HB-GRAL wrote:
>
> >
> > Hi Adrian
> >
> > Maybe this link could contain some useful information for you, I don’t
> > know ...
> > http://trac.osgeo.org/postgis/wiki/WKTRasterTutorial01
> >
> > As far as I understand you're working with sqlite. I don’t know if this
> > is the best dbms for what you’re doing (problems with indexing, filelock
> > etc.). Here is a postgres alternative which extends sqlite core for GIS:
> > https://www.gaia-gis.it/fossil/libspatialite/index
> >
> > -Yves
> >
>
> Hi Yves,
> I have to work with sqlite as it is an embeddable database (like you can
> take
> the file and use it anywhere). For my purposes it's the only solution.
> But the bottleneck is not in sqlite anymore.
> Meanwhile I've identified a bug which made my code incredibly slow.
> Right now I'm looking at 10 full days to fill a 10x10 degree elevation
> database with material info. I will try to optimize even further, I
> believe I
> can. I'm using output from ogr-decode, srtmchop and terrafit. I will try to
> keep the wiki article updated too.
>
> I tried using GEOS directly but it segfaults quite often with latest
> version,
> so I abandoned it. Right now I'm using GDAL/OGR with GEOS bindings.
>
> With this, terrain sampling 100-1000 km away will be possible, as long as
> one
> keeps the number of sampled points reasonable. Size of the database
> remains a
> problem, as well as time to get it.
>
> Cheers,
> Adrian
>
>
>
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