[OpenLayers-Users] Resolutions with Geowebcache and
ahocevar at opengeo.org
Tue Jul 27 04:40:02 EDT 2010
the problem I see with your approach is that OpenLayers.Control.GetFeatureInfo creates a GetFeatureInfo request for the map extent, not for a tile. I would recommend sending GetFeatureInfo requests to the underlying WMS, as explained in http://getsatisfaction.com/opengeo/topics/error_in_wmsgetfeatureinfo#reply_2612983
On Jul 27, 2010, at 08:55 , Miles Jordan wrote:
> I've been debugging a problem that I've been having with using the WMSGetFeatureInfo control and GeoWebCache.
> Basically I am setting OpenLayers.DOTS_PER_INCH to 90.71428571428572 which is what GeoWebCache expects by default, however when the WMSGetFeatureInfo request goes through to GeoWebCache it is like it's using the default 72 for DOTS_PER_INCH, because all of the resolutions are about 21% out.
> GeoWebCache responds with messages such as :"400: Requested horizontal resolution: 0.54931640625 , best match: 0.703125 exceeds 10% threshold. Perhaps the client is configured with an incorrect set of scales (resolutions), or the DPI setting is off compared to the one in GWC ?"
> I've actually just dropped the WMSGetFeatureInfo control into a GeoWebCache OpenLayers demo, so the resolutions are definitely set up to match. The full source (pretty short and simple) is at http://pastebin.com/JENnAPC9.
> I've brought it up on the GeoWebCache mailing list but now thinking that it's more likely something to do with OpenLayers. Here's a link to my messages: http://tinyurl.com/38jvcva
> It seems like the resolution would be calculated incorrectly by about that amount if the DOTS_PER_INCH were still at 72, so I'm wondering if there's another setting that I need to change or if there's a bug somewhere.
> Your comments are appreciated.
> Miles Jordan
> Acting Manager / Systems Analyst
> Australian Antarctic Data Centre
> Australian Antarctic Division
> Dept. of the Environment, Water, Heritage & the Arts
> Australian Antarctic Division - Commonwealth of Australia
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