[Tilecache] That old tile index problem again

[Joanne Cook]

Hi All,

I'm sorry to have to ask this question, as you must all be sick of it, but I am having the "couldn't calculate tile index" problem. Until I decided I needed to use tilecache to speed things up, I didn't put anything about extents or resolutions in my openlayers map, and everything worked fine, but of course now I need to include these things and it's showing up my ignorance somewhat!

I am very confused as to which bounding box we are talking about- the bounds of the map or of the layer?

Then I can't figure out what my maxResolution should be, because I've never set any scales, zoom levels or resolutions in my map before. 

I have tried getting the bounding box of the layer from geoserver (which is serving my wms) and then divide the width of that by 512 to get the max resolution but that doesn't work for me so I assume I have missed something somewhere.

I have also tried figuring out what the bounding box of the whole openlayers map is when it's initially loaded, by looking at the errors for the tiles in the top right and bottom left corners, but that doesn't work either.

This is the address of the openlayers map that works with no tilecaching:
http://mapdata.thehumanjourney.net (it's quite slow, hence the need for tilecaching)

This is the address of the openlayers map that doesn't work at all:
http://mapdata.thehumanjourney.net/index_tc.html

I'm sorry to have to ask for assistance in such a long-winded way, but searching for the answers else where has just got me more and more confused and I would really like to understand what's going on...

Many thanks

Jo

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Joanne Cook
Information Systems Coordinator
Oxford Archaeology (North)
01524 541000
http://thehumanjourney.net



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