[Gvsig_english] New Student for GVSIG within Google Summer OfCode2010: quick introduction

Francisco José Peñarrubia fpenarru at gmail.com
Mon May 17 09:56:05 CEST 2010


Hi Ben and Luca.

Not many people is aware of this, but.... Nacho Brodin, one of the main 
developers of raster support in gvSIG told me some time ago that he did 
some work related to support OGR bindings from GDAL 
(http://www.gdal.org/ogr/).
The idea is great, gvSIG will be able to support a lot of formats with 
only one library....among them, you can find SQLite Spatial format: 
http://www.gdal.org/ogr/ogr_formats.html

As far as I know, Nacho was able to do it, but the results were poor in 
order of speed.

Maybe Nacho can explain better than me his results. If this is true, I 
think it would be interesting to have some tests in order to decide if 
you go JNI way or pure Java way.

Best regards.

Fran.

Benjamin Ducke escribió:
>> Ben,
>>
>> you know for sure much better than me what would mean having problems
>> with wrapping of C API so if we will have too much pain with
>> SpatiaLite it could be perfect use the plain WKT/WKB.  I've given a
>> glance to the link you've suggested but I should read it better for
>> understanding what it means on the development point of view.
>>
>> Ciao,
>> Luca
>>
>>     
>
> I think for a first stage implementation, the simple WKB/WKT
> storage model is probably best. Others can always be added later
> using the new GDAL 1.7 java bindings. That way, you shouldn't
> have to worry about maintaining your own JNI stuff (which can
> be a real pain).
>
> Give users the choice to use WKB (more compact) or WKT (more
> easy to parse) when storing geometries. When reading, the
> format should be auto-detected.
>
> Let me know if you have any problems understanding anything.
> I can send you a little sample SQLite3 database with some WKB/WKT
> tables for illustration. I produced them in GRASS GIS using the
> GDAL/OGR drivers.
>
> But maybe start by adding plain SQLite3 non-spatial tables as
> a new project document type first. And then work towards spatial 
> tables from there -- to keep things a little more simple for you 
> at the start!
>
> Best,
>
> Ben
>
>   
>> [1]http://www.iosa.it/blogs/luca
>> 2010/5/14 Benjamin Ducke <benjamin.ducke at oxfordarch.co.uk>
>> Hi Juan, Luca
>>
>> That question is not so rhetorical, actually!
>> There are several ways of storing spatial data in an SQLite3
>> database, that are all in use by some software:
>>
>> http://www.gdal.org/ogr/drv_sqlite.html
>>
>> One of them is a simple WKT/WKB storage model that is also nicely
>> documented (see link above).
>>
>> So if SpatiaLite is too much pain, because of the need to wrap the
>> C API, then we can just use the plain WKT/WKB storage for our
>> purposes.
>> It's supported by GDAL/OGR, so we lose only the special SpatiaLite
>> functionality.
>>
>> Cheers,
>>
>> Ben
>>
>> ----- Original Message -----
>> From: "Juan Lucas Dominguez Rubio" <jldominguez at prodevelop.es>
>> To: "Users and Developers mailing list"
>> <gvsig_internacional at listserv.gva.es>, "Gvsig internacional"
>> <Gvsig_internacional at listserv.gva.es>
>> Sent: Friday, May 14, 2010 2:38:44 PM GMT +01:00 Amsterdam / Berlin /
>> Bern / Rome / Stockholm / Vienna
>> Subject: Re: [Gvsig_english] New Student for GVSIG within Google
>> Summer Of Code2010: quick introduction
>>
>>
>>
>>
>> Ciao, Luca.
>>
>> I too think Spatialite is a very interesting way to store and share
>> GIS data, especially because its simplicity fits mobile devices very
>> well.
>>
>> I know a pure-Java version of SQLite (not Spatialite) which will
>> probably work on a wide range of Java-enabled mobile devices (Android
>> supports SQlite too).
>>
>> I was wondering: what is the simplest Sqlite database that can be read
>> and processed from Spatialite? Let's suppose I have a Sqlite database
>> file with only one table and one of the columns of that table is of
>> binary type (BLOB or similar), and that column contains some WKB
>> describing a geometry. Would this be enough to open it from a
>> Spatialite-enabled application (for example gvSIG in the future)? This
>> is rather a rhetorical question... I need to look into it myself :)
>>
>> Can we see your progresses online? blog? SVN?
>>
>> Regards,
>>
>>
>> Juan Lucas Domínguez Rubio
>> ---
>> Prodevelop SL, Valencia (España)
>>
>> Tlf.: 96.351.06.12 -- Fax: 96.351.09.68
>> http://www.prodevelop.es
>> ---
>>
>>
>> De: gvsig_internacional-bounces at listserv.gva.es en nombre de luca
>> bianconi
>> Enviado el: jue 06/05/2010 15:17
>> Para: Gvsig_internacional at listserv.gva.es
>> Asunto: [Gvsig_english] New Student for GVSIG within Google Summer Of
>> Code2010: quick introduction
>>
>>
>> Hello gvsig-international mailing list,
>>
>> sorry for sending this email as a kind of spamming, I'd like just to
>> introduce myself quickly to the whole list.
>>
>> My name is Luca Bianconi and I'm the "student" working with the gvSig
>> team for the Google Summer of Code 2010.
>> Our task is implementing the gvSig support for SQlite and SpatiaLite
>> and I'll do my best for doing it.
>>
>> I'd like to say my "Hello" to everybody and I thank you all for the
>> help you will be able to provide when we will be up to the
>> implementation phase both in comments and suggestions!
>>
>> Nice to meet you all,
>> Cheers,
>> Luca
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