[Tilecache] SRS parameter

[Gregor Mosheh]

> We are thinking of implementing SRS switching in TileCache (we could 
> generate independently, let's say, 3 levels in EPSG4326 and 7 levels in 
> EPSG27582, with potentialy level overlaps and requests the same 
> TileCache and the same layer in EPSG4326 and EPSG27582)

That seems like the best route, yes. Have X zoomlevels in one 
projection, and Y levels at the other projection, use minScale and 
maxScale to have your map client (OL?) switch between them. You'd have 
to replicate the same layer-zoom-setup in tilecache.cfg as in your map 
client, but that doesn't sound too bad.


> I do not know 
> much about TileCache code architecture but I imagine we could add a top 
> level folder in the tile storage that specifies the SRS

TC creates the directories using the name of the layer (e.g. 
nations_projected and nations_latlon) and under that the zoom level (00 
through 12 for example) but you probably won't need to concern yourself 
with it at this stage. If you have the projection-change working via 
plain WMS, just swap in TC's URL and you should be good to go.

-- 
Gregor Mosheh / Greg Allensworth, BS, A+
System Administrator
HostGIS cartographic development & hosting services
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