Re: Caching tiles locally?

["Zeeshan Ali (Khattak)" <zeeshanak gnome org>]

Hi Fabrice,

Just FYI, the current caching methods downloads tile images and can
easily take a huge amount of disk space. We are hoping that Jonas'
work will client-side rendering possible and once that is the case, we
have a good platform to cache vector tiles instead, which consume a
lot less disk space.

http://jonasdn.blogspot.se/2015/05/client-side-rendering-of-our-map-using.html

On Thu, May 14, 2015 at 1:21 PM, Jiří Techet <techet gmail com> wrote:
> Hi Fabrice,
>
> in principle you have to get the map source from the view using
>
> champlain_view_get_map_source()
>
> then get x, y tile coordinates using
>
> champlain_map_source_get_x()
> champlain_map_source_get_y()
>
> for specific latitude and longitude and create a new tile with these
> coordinates using
>
> champlain_tile_new_full ()
>
> (tile size is 256). At this point you may also want to connect the
> "render-complete" signal to know when tile gets loaded. Now call
>
> champlain_map_source_fill_tile()
>
> The tile will be filled and cached automatically in libchamplain cache under
> ~/.cache/champlain.
>
> Now you'll have to do the above in a loop for the area you are interested in
> and also for the zoom levels you are interested in.
>
> But most importantly, make sure you follow the terms of use of the tile
> provider you are going to use. See for instance the section "Bulk
> Downloading" here
>
> http://wiki.openstreetmap.org/wiki/Tile_usage_policy
>
> This is also the reason why you have to do such a thing manually (provided
> you know what you are doing and it's legal) and there's no single-call
> function directly in libchamplain so people don't cause high load on the
> tile servers.
>
> Cheers,
>
> Jiri
>
>
> On Thu, May 14, 2015 at 12:56 PM, Fabrice Delente <delentef gmail com>
> wrote:
> > Hello,
> >
> > I use libchamplain in python+GTK3 to create a small GPS viewer for the
> > tracks I run in my hometown. I'd like to cache the data for my town on
> > my computer, so that I don't have to reload the data from the web.
> > I've looked at the API but don't see how I can do that, can anybody
> > give me directions? Thanks.
> > _______________________________________________
> > libchamplain-list mailing list
> > libchamplain-list gnome org
> > https://mail.gnome.org/mailman/listinfo/libchamplain-list
>
>
>
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-- 
Regards,

Zeeshan Ali (Khattak)
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