[OpenLayers-Dev] Scale dependencies with TileCache

[Christopher Schmidt]

On Tue, Sep 04, 2007 at 03:28:20PM -0400, fporcelli at taic.net wrote:
> Chris --
> 
> I passed the resolutions array to TileCache but I get pink tiles when the layer is turned on outside the boundaries of the resolutions array. The layer does render properly when zoomed in at the supported resolution. My units are decimal degrees, and my TileCache layer looks like so.


I'm sorry: "When the layer is turned on outside the boundaries of the
resolutions aray" -- how? The minScale/maxScale should be causing 
the layer's visibility to be set to false outside of that min/max scale
range -- if it's not, that's a bug, as far as I'm aware. Can you create
a minimal demo? 

-- Chris

> I'm scratching my head on this one...
> 
> [testlayer]
> type=WMSLayer
> url=http://gis.test.com/cgi-bin/dir/test_wms.cgi
> transparent=true
> extension=png
> layers=1
> resolutions=0.00034332275390625,0.000171661376953125,0.0000858306884765625,0.00004291534423828125
> 
> Regards,
> 
> Frank
> 
> 
> -----Original Message-----
> From: Christopher Schmidt <crschmidt at metacarta.com>
> Sent: Tue, September 4, 2007 12:22 pm
> To: fporcelli at taic.net
> Cc: dev at openlayers.org
> Subject: Re: [OpenLayers-Dev] Scale dependencies with TileCache
> 
> On Tue, Sep 04, 2007 at 12:05:28PM -0400, fporcelli at taic.net wrote:
> > Hello --
> > 
> > I was interested in creating a cached layer with scale dependencies using TileCache. The layer configuration using just OpenLayers works fine and is shown below. However I want to cache this layer and have tileCache only request tiles from within the minScale and maxScale parameters. Is this possible?
> 
> TileCache needs to be handed a list of resolutions. It's not clear to me
> what your units, maxExtent, etc. are. You should set your TileCache
> layer up to have the *resolutions of the base layer* which exist between
> those scales.
> 
> OpenLayers.Util.getResolutionFromScale may be useful.
> 
> Regards,
> -- 
> Christopher Schmidt
> MetaCarta
> 
> 

-- 
Christopher Schmidt
MetaCarta