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Use OSM offline

chakopelli's picture
Thu, 06/04/2009 - 23:51 — chakopelli

Hello,

i know it's possible to download the whole content of openstreetmap. But is it possible to integrate the osm content in bt747 to use this application complete offline?

I don't want to cache only a litte peace of osm i want to integreate osm complete if its possible, is it?

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Fri, 06/05/2009 - 11:00 — mdeweerd
mdeweerd's picture

Doable ...

Today this functionality is not 'available' in BT747 but it is possible to add it.

The amount of work involved depends on how this offline database is presented.

If the offline database is available as tiles that can be 'requested' through a URL (including file:// !), the implementation is fairly quick.

If the offline database is a vector database and one must calculate the rendering of the individual items, then there is more work. I've seen an opensource java application that can render (I do not have the name in mind right now) so that could be 'integrated' to BT747. The other solution is to have a rendering application act as a local tileserver. That would be a more generic and reusable solution (e.g., you could even see maps in your browser).

I'll let you look into this. If there is 'little' to do in BT747, I'll do it.

Fri, 06/05/2009 - 13:36 — Anonymous

Doable

hmmm ok i had a look

there a three options:
here you could download something of osm:
http://wiki.openstreetmap.org/index.php/Planet.osm but i don't much about it ...

there are 3 programms that render this data i think

Kosmos (which runs on windows an could render the data to pictures with an xml file) i think i test this programm
http://igorbrejc.net/kosmoshome

the other two programms look like more complicatet and only render...:
http://wiki.openstreetmap.org/wiki/Osmarender/Howto
and Mapnik

sorry very complicatet stuff for me :)

Fri, 06/05/2009 - 14:24 — mdeweerd
mdeweerd's picture

A better option ...

http://wiki.openstreetmap.org/wiki/Howto_real_time_rendering_with_Java

which does still require some work but is likely the most appropriate code available.

gpsmid is also in java but in J2ME and not opensource I think.

Sun, 06/07/2009 - 15:49 — Anonymous

i think i have to learn java

i think i have to learn java ^^

Tue, 06/09/2009 - 06:19 — Imroy
Imroy's picture

GpsMid licence

The GpsMid sourceforge site says it's released under the GPL v2 license.

Tue, 06/09/2009 - 09:48 — Imroy
Imroy's picture

Prefer vector

If you're asking which I would prefer, it would definitely be a vector map. I've played around with a number of J2ME apps over the last few months and have found that:

  1. Each tile is mostly only useful for one level of zoom, so you end up downloading data for each area many times. Sure, you can scale the tiles, but it's not the best solution.
  2. Individual tile images are small and with the overhead of HTTP it takes a long time to download enough to cover a large area.
  3. The numerous small files are not well suited to storage on flash cards using a FAT filesystem. They can be compiled into larger files however.

Vector data is multi-purpose. The same dataset can be used for rendering a map (at any zoom level), searching for street/suburb/etc names, and for routing. Tile images give you a nicely rendered map (or aerial photograph) but not the other data.

Those are my thoughts.

Tue, 06/09/2009 - 11:41 — mdeweerd
mdeweerd's picture

You are right. I did not

You are right. I did not remember at the time and did not check the site.