[OSM-talk] Newbie - queries and usability suggestions

[Lars Aronsson]

Calum Polwart wrote:

> OK I'm new here, but having a few issues - I'm reasonably 
> computer savy so it worries me slightly that you will loose 
> potential volunteers because the userfriendlyness is (a bit) 
> rough around the edges.

With time, the worry wears off.

> I've uploaded a track, and started doing some mapping from it.  
> That's fine.  But because my track in above 54' N it doesn't 
> render on slippy.

The new slippy map is useless.  The old slippy map was useless 
too, but in different ways.  Every approach I have seen has been 
useless in its unique way.

So how can you avoid apathy and cynicism?  Look for solutions that 
allow you to work offline, independent of the central servers (API 
or slippy map).  The wiki still works.  Go driving to collect 
track logs.  Play with Osmarender.  Try the German algorithm (I 
put the link in my diary some time back, [[user:LA2]] on the wiki) 
for automatic map generation from track logs.

Ultimately, we need some solid GIS experience on how to make the 
database, API and slippy map generation fast and scalable.  A new 
tile must be generated in a tiny fraction of a second (20 ms or 
so), independent of the scale, and it must be possible to 
invalidate only the right parts of the tile cache.  In a map of 
England, the tile that covers London is the real challenge.  It is 
based on many thousands of line segments, and doesn't really need 
to be redrawn if only a small street is modified.  I think there 
must be abstraction layers in the database and API that correspond 
to the zoom levels, so that changes in small details don't 
propagate to (and invalidate cached tiles at) all zoom levels. If 
you can download the database dump, play with this, and create a 
fast slippy map, you could rescue the entire project.


--
  Lars Aronsson (lars at aronsson.se)
  Aronsson Datateknik - http://aronsson.se