[OSM-dev] Projection Issues

[Christopher Schmidt]

On Wed, May 31, 2006 at 02:30:23PM -0400, Christopher Schmidt wrote:
> On Wed, May 31, 2006 at 06:45:35PM +0100, Nick Whitelegg wrote:
> > >At this point, I'm largely just confused, and I'm willing to
> > >admit that I think with the current setup, OSM and OpenLayers simply
> > >aren't going to work together. I don't claim to understand projections
> > >well enough to know what's going on, and without knowing that, I can't
> > >begin to create a tile system that will grab tiles in the same format as
> > >OSM currently is.
> > 
> > Having seen this talk of OpenLayers, I was going to experiment with it 
> > this evening to see if it will talk to the new renderer (see recent dev 
> > posts). Will OpenLayers accept the URL of a simple WMS-compliant server 
> > i.e. a script which accepts bbox, width, height and layers parameters? I 
> > note that the examples e.g. the Boston Free Map take a ".map" file which 
> > is (I believe) a configuration file for Mapserver, but presumably 
> > OpenLayers will talk to any WMS server.
> 
> Yep. The mapfile is just a configuration file, but OL will talk to any
> WMS. 
> 
> The problem I was having with the new renderer is a 'zoom' parameter,
> which I wasn't sure what effect it had :) But it does seem that the new
> dev renderer works fine in OL:
> 
> http://crschmidt.net/projects/openstreetmap/devrender

To alleviate slow-loading tiles, I'm now passing the tile requests
through my local squid proxy so if you see a URL with
http://crschmidt.net/services/pipe? in it, that's what it is. 

I could skip one level of indirection if Expires headers were set -- even an
hour would probably greatly improve the usability of the interface. The
services/pipe proxy just adds a 6 hour Expires header, and the second
proxy is to ensure this newly-cachable tile gets caught by squid.

-- 
Christopher Schmidt
Web Developer