Hi Chris, Thanks for the clarification. FYI, I worked around this issue by creating a subclass of OpenLayers.Layer.WMS and overriding the getURL() method. The new method checks the latitude bounds, setting the URL to that of a fixed blank image if out of bounds. This blank image is cached by the browser, reducing server round-trips significantly.
See http://behemoth.nerc-essc.ac.uk/ncWMS/js/WMS1_1_1.js. (You might also notice that I've added a little extra sophistication to allow different values of the key used for SRS. WMS1.1.1 uses "SRS" while WMS1.3.0 uses "CRS". I also have a WMS1_3 class that subclasses WMS1_1_1 and takes advantage of this). Cheers, Jon On Sun, Jun 1, 2008 at 7:34 PM, Eric Lemoine <[EMAIL PROTECTED]> wrote: > On Sun, Jun 1, 2008 at 3:53 PM, Christopher Schmidt > <[EMAIL PROTECTED]> wrote: >> On Sun, Jun 01, 2008 at 02:10:46PM +0200, Eric Lemoine wrote: >>> On Fri, May 30, 2008 at 4:24 PM, Christopher Schmidt >>> <[EMAIL PROTECTED]> wrote: >>> > On Fri, May 30, 2008 at 01:48:36PM +0100, Jon Blower wrote: >>> >> I've noticed that in my application OpenLayers is requesting tiles >>> >> outside the maximum extent of my overlay layer (which is in EPSG:4326 >>> >> and hence has a maxExtent of -180,-90,180,90). I've checked using the >>> >> Firebug console that the maxExtent is correctly set. wrapDateLine is >>> >> set true. >>> > >>> > wrapDateLine forces displayOutsideMaxExtent, which is why you are seeing >>> > the behavior you are seeing. >>> >>> Chris, sorry for the stupid question but why does wrapDateLine force >>> displayOutsideMaxExtent? What would not function if one creates a >>> layer with wrapeDateLine:true and then does >>> layer.displayOutsideMaxExtent = false? One will end up with missing >>> tiles? >> >> The 'wrapped' tiles are, in actuality, still going from (for example) >> -360 to -180 in the 'mind' of OpenLayers. We just fake the *request* >> bbox, not the place the tile actually thinks of itself as being: without >> displayOutsideMaxExtent, this obviously wouldn't work. > > I'm not familiar with the wrapdateline code, thanks for the explanation Chris. > > Cheers, > > -- > Eric > -- -------------------------------------------------------------- Dr Jon Blower Tel: +44 118 378 5213 (direct line) Technical Director Tel: +44 118 378 8741 (ESSC) Reading e-Science Centre Fax: +44 118 378 6413 ESSC Email: [EMAIL PROTECTED] University of Reading 3 Earley Gate Reading RG6 6AL, UK -------------------------------------------------------------- _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
