[Marble-devel] Marble with offline OSM maps

[Torsten Rahn]

Hi,

On Dienstag, 15. Mai 2012 12:01:29 Jeremie Scheer wrote:
> I'd like to use Marble as a Qt Widget on an embedded system that runs
> with an ARM processor.

You might want to default to Mercator projection in Marble since that delivers 
the best speed. This might especially be relevant on embedded systems and ARM 
devices. 
 
> So, as my system isn't connected to the Internet, I must be able to
> directly use OSM vector files in Marble to display maps.

It's trivially easy to preload the tiled bitmaps and it's also easy to preload 
the routing/search info.

Vector rendering and vector data however is still considered to be at an 
experimental stage:

Have a look at 

http://www.youtube.com/watch?v=QnZDkxj2SUU&feature=player_embedded

to see it in action. Or see 

http://devel-home.kde.org/~tackat/gsoc2012/marble-bitmapvector.jpg

bitmap version on the top, vector version of the same map on the bottom for 
comparison.

As you can see there are still a few things missing (road labels, etc.) but we 
gladly accept patches ;)

Note that Marble currently only support import of single files. So there is no 
"tile management" as it exists for the OSM bitmap map theme.
 
> Is it possible to do that with Marble ? And if so, could you explain me
> the way it can be done (directly by code and not in Marble menus) ?

Have a look at 

http://techbase.kde.org/Projects/Marble/MarbleCPlusPlus

and the pages that follow.

Looking at the source code it looks like 

myMarbleWidget->model()->addGeoDataFile("/home/thatsme/marbletown.osm") 

should do the trick.

Speed depends on the file size, so smaller files generally result in better 
performance.

BR,
Torsten


 
> Thanks,