Re: [weekly report] Week 3: local map rendering in libchamplain

[Simon Wenner <simon wenner gmail com>]

Pierre-Luc Beaudoin wrote:
> On Mon, 2009-06-15 at 16:27 +0200, Simon Wenner wrote:
>   
>> A more severe problem was the acquisition of data for the lower zoom
>> levels. All OSM-API server I know were _very_ slow or down. I had to
>> use a 300MB dump of Switzerland to do my tests, which was painful. I'm
>> thinking about setting up my own server. I could use it for the
>> development of the network map source too.
>>     
> AFAIK, other applications that provide such local rendering, do not
> offer "lower" zoom levels.  Even Open Street Map combines thousands of
> tiles to make the 0-2 levels.  We could have an hybrid map source (tiles
> + rendering) or simply limit it to higher levels.
>
>   
Yes, but we should be better than all other solutions! :D
It's low priority, but it has nice use cases. It's not realistic for
'full' planet data, but you can filter the OSM xml data to fit your
specific application needs and render this small data set directly to
low zoom levels.

An example I tried: (some rivers and lakes of Switzerland, level 6, one
tile)
http://wenner.ch/files/public/simon/tmp/water_CH_Z6.png
>> After these tests I created a champlain branch and committed a first
>> prototype of a local map source using libmemphis with a small data
>> set.
>> It worked better than expected. It runs smooth on high-end machines,
>> but the map locks on high zoom levels on weak systems. This week I
>> will
>> evaluate a thread pool for rendering and start to implement the final
>> class hierarchy.
>>     
> I tried that yesterday. It is awesome :D  Sure, it is a prototype, but
> it certainly proves that it can be done hehe Good work!
>   
Thanks!
> Pierre-Luc
>
> Note: Don't forget to send your report to libchamplain-list gnome org
> too!
>   
*note*