[OSM-talk] calculating lon/lat bounds from tilename

[Jon Burgess]

On Fri, 2007-06-22 at 15:44 -0400, Matthias Julius wrote:
> Jon Burgess <jburgess777 at googlemail.com> writes:
> 
> > Would the proper solution be to provide OSM tiles in a latlong
> > projection? Mapnik is certainly capable of rendering these. 
> 
> What do you mean with a latlong projection?  A projection where each
> degree has the same spacing all over the map and no matter the
> lattitude?  That is getting more and more distorted the farther you
> get from the equator.
> 
> Matthias
> 

Yes. 

Whether this distortion is more or less acceptable than tiles where the
lat/lon are non-linear across the tile depends on what you are trying to
achieve. I think a 3D representation is the only thing that people agree
is 'fair'. All 2D projections suffer from at least one weakness or
another.

By the sound of things people have applications which want to work in a
nice simple square lat/lon grid. For these applications, tiles which can
map to a lat/lon grid are probably much easier to work with than the
current slippy mercator projected tiles. 

	Jon