[Marble-devel] Questions about marble

[Torsten Rahn]

Hi Christophe,

On Wednesday 02 June 2010 15:02:45 Christophe Leske wrote:
> thanks to the help of Sylvain Pareé, we got Marble compiled andworking
> on the Windows platform, including QtDesigner and QtCreator (albeit the
> later one without proper display of the widget).

So does http://techbase.kde.org/Projects/Marble now contain full up-to-date 
instructions how to achieve that? :-)
 
> I would now like to look into creating layers for it taken from the
> naturalearth project pages (see http://www.naturalearthdata.com/)

That looks familiar. Are you aware that Marble's Get Hot New Stuff as well as 
this page

http://edu.kde.org/marble/maps.php
 
contains some of this data provided as tiles already?

> I got already a WorldWind tiling scheme set from it, but it appears as
> if Marble uses a Quadtree tiling scheme, right? 

Correct.
Start Marble with 

marble --tile-id 

to see how it works.

> So I need to reconvert
> the files...

Might be necessary. However Marble also supports several tile layouts and 
different Url schemes and projections. So this might be a matter of changing the 
dgml file.
 
> Also, is there in Marble a way without additional coding to ...
> 
> - show multiple layers of data (several layered pngs with transparency
> in them?)

Jens-Michael Hoffmann ("jmho") has recently worked on such a feature. It should 
work in Marble 0.10.x already. Maybe jmho can give a few instructions how to 
accomplish this? :)

See:

http://jmho4.wordpress.com/2010/05/24/new-marble-feature-quick-dirty-wms-
support-bybernhard-beschow-shentey/

> - modify the cityplacemarks database?

Yes,

http://websvn.kde.org/trunk/KDE/kdeedu/marble/data/placemarks/HOWTO-
cities.txt?view=markup

Note however that there is a bug in Marble which currently prevents 
regeneration. Harshit Jain has recently created a patch which fixes it but also 
adds some initial geonames.org support

http://reviewboard.kde.org/r/4006/

Most likely the actual fix will get seperated out and backported.

>  From the DGML file, I can see that the cityplacemarks are supposed to
> be in a KML file, yet I can only find .cache files

The cache files are generated from the KML files by Marble. We only ship the cache 
files in the package and only install them. The original KML files are part of the 
source code.
 
> (e.g. C:\Program Files\marble\data\placemarks\cityplacemarks.cache)
> 
> What is the format of these files, how can I open and modify and/or
> replace these?

See above.

Best Regards,

Torsten