[OSM-dev] [OSM-newbies] URL for mobile binary protocol

Martijn Pannevis openstreetmap at panman.nl
Thu Mar 20 11:54:25 GMT 2008

Robert (Jamie) Munro wrote:
> Hash: SHA1
> Jason Dent wrote:
> | I have a mobile map application.  I have found that directly accessing the
> | tile server works the best.
> The downloads are HUGE! Some people have to pay per kB for mobile
> downloads. Also, you can't rotate and reproject the tiles, or give a
> sat-nav type 3d view, without horribly distorting the text. If you want
> to highlight a road or a point, you have to download the map details anyway.
> | Trying to draw all the map details at runtime
> | on a PDA is a bit much.  It can be done, but pre-cooked tile are much
> | better.
> It's not "a bit much". *All* commercial sat-navs do it. When you
> consider how much more CPU power a modern PDA has than a PC of 15 years
> ago, and think about the kind of thing those PCs did (Doom, for example)
> drawing a map is easy.
I agree that technically redering tiles on the mobile probably would be 
the best solution, certainly in terms of data traffic.
However, to get nice looking tiles, you'd have to implement something 
like mapnik, on your device. I know it already took us quite some work 
to implement a nice map with scrolling tiles in J2ME. I'm sure building 
that with vectors, which scale with zoomlevels, and look nice, would 
take months, if not years, of development time. Thats why we choose to 
use tiles.
I do want to look into more efficient ways of getting tiles, or parts of 
them, to the mobile.
Kind Regards,
Martijn Pannevis.

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