[Marble-devel] How to know when all tiles/data needed for rendering are available?

[Friedrich W. H. Kossebau]

Hi Anders,

Am Montag, 19. März 2012, 19:42:12 schrieb Anders Lund:
> Mandag den 19. marts 2012 19:30:06 skrev Friedrich W. H. Kossebau:
> > Background:
> > I am currently looking into making the Map shape plugin for Calligra
> > usable.  E.g. for rendering to the printer or to a PDF document. There the
> > resolution is much higher than on the screen (Retina display is not so
> > common yet  ), so other tiles are needed for a proper output.
> 
> do not forget that those tiles will differ from the ones in a lower zoom
> level, it may be better to scale the tiles you have. Map tiles use graphics
> that are not meant for printing resolutions, eg 16px icons and fonts aimed
> at screen display.

Hm, good hint, did not yet think about that, might have hit me next. Higher 
resolution also would mean more detail... (meanwhile also e.g. found and read 
http://wiki.openstreetmap.org/wiki/OSM_on_Paper)

So indeed scaling the tiles would be better, so the printed output matches the 
screen output.

But:
I wonder if at least the things which are rendered inside Marble should 
consider the dpi resolution (and we also all hope for local OSM rendering to 
arrive a day)? A grep for DPI at least did not yield anything resolution 
related. Mh, chance for an improvement that is, no? ;)
After all in the (already started) future "screen display" could not simply be 
assumed to be ~100 dpi. Okay to file a bug about that?

And given that I might not be the only one who would like to use Marble to 
also render to paper/higher resolution ideally that scaling of tiles could 
also be provided by Marble::MarbleMap.

I guess a patch from me is welcome ;) But no hope on me doing that, my WIP 
stack is too high ATM :/ But if someone reading this is working in that area 
and can consider this problem, she/he would help to make the Map plugin for 
Calligra shine in the future :)

Another usecase I can think of is a Marble plugin for kdenlive, to visualize 
how someone travels between places of a story (e.g. someone doing a lovely 
vacation report "... then we drove to Helsinki...", could even use real track 
data). That rendering also needs to know about having all data available and 
ideally can render as much as possible directly to the video format 
resolution.

So consider this a real problem for "Marble everywhere" :P

Cheers
Friedrich