[OpenLayers-Users] Ka-Map layer - kaOrigin?

[Jeff Dege]

That would explain why I was seeing tiles generated in ka_cache, but
nothing displayed.

Thanks.

(Of course, until I moved to trunk, instead of release-1.0, I wasn't
seeing tiles generated in ka_cache ... you deal with one problem at a
time.) 

> -----Original Message-----
> From: Tim Langlois [mailto:tlanglois at archetypecorp.com] 
> Sent: Tuesday, August 15, 2006 12:07 PM
> To: Jeff Dege
> Cc: users at openlayers.org
> Subject: Re: [OpenLayers-Users] Ka-Map layer - kaOrigin?
> 
> Make sure the tile width and height configured in ka-map's config.php
> matches the size you are using with openlayers.  You can 
> check the error
> logs of your webserver to see if openlayers is requesting image files
> that do not exist.  This is what happens when the tile sizes do not
> match.
> 
> On Tue, 2006-08-15 at 10:12 -0500, Jeff Dege wrote:
> > Among the things I've been trying, to see if I could get acceptable
> > performance with the map data I've been working with, is to try the
> > Ka-Map layer, hoping that the tile caches would make a difference.
> > 
> > I've been unable to get the Ka-Map layer to work, and I've 
> been digging
> > into why.
> > 
> > I'm working with the release-1.0 code.
> > 
> > I'm declaring the layer as:
> > 
> > 	var baseLayer = new OpenLayers.Layer.KaMap("Cities",
> > 			"http://localhost:8080/kamap/tile.php?",
> > 			{ 'map': 'gmap', 'g': 'all', 'i': 'png' },
> > 			'degrees', 
> > 			72 );
> > 
> > and as far as I can see, that's correct.  At least it matches the
> > instructions at:
> > 
> >  
> > 
> http://mailman-viper.python-hosting.com/pipermail/users/2006-J
> une/000058
> > .html
> > 
> > The problem is in KaMap.js - the initialize function takes four
> > arguments:
> > 
> >     initialize: function(name, url, params, origin) {
> >         this.kaOrigin = origin;
> >         var newArguments = new Array();
> >         newArguments.push(name, url, params);
> >         OpenLayers.Layer.Grid.prototype.initialize.apply(this,
> > newArguments);
> >         this.params = (params ? params : {});
> >         if (arguments.length > 0 && params) {
> >             OpenLayers.Util.applyDefaults(
> >                            this.params, 
> >                            this.DEFAULT_PARAMS
> >                            );
> >         }
> >     },
> > When I stick in an alert to print the values, 'name' = 
> "Cities", 'url' =
> > "http://localhost:8080/kamap/tile.php?", and 'origin' = "degrees".
> > 
> > You can see that 'this.kaOrigin' is assigned "degrees".
> > 
> > But in the next function, 'this.kaOrigin' is referenced as 
> if it had lat
> > and long member variables:
> > 
> >     addTile:function(bounds,position) {
> >         var zoom = this.map.getZoom();
> >         var resolution = this.map.getResolution();
> >         var scale = 128000000 / Math.pow(2, zoom);
> >         // 1280000 is an empirical value for a specific 
> tile server, not
> > yet figured out the
> >            right way to do this in general.
> >         // This will probably be based on map.maxResolution.
> >         var cellSize = new 
> OpenLayers.Size(resolution*this.tileSize.w,
> > resolution*this.tileSize.h);
> >         var pX = Math.floor(((bounds.left + this.kaOrigin.lon) /
> > cellSize.w) * this.tileSize.w);
> >         var pY = -Math.floor(((bounds.top+this.kaOrigin.lat) /
> > cellSize.h) * this.tileSize.h);
> >         var url = this.getFullRequestString(
> >                       { t: pY, 
> >                         l: pX,
> >                         s: scale
> >                       });
> > 
> > The result is that pX and pY are both assigned values of 
> NaN, and the
> > URL returned by getFullRequestString() contains "t=NaN&l=NaN", which
> > results in the KaMap server-side scripts drawing and returning empty
> > tiles.
> > 
> > >From what I can see, kaOrigin is only referenced in these 
> two locations
> > - there isn't any other code, anywhere else, that is 
> changing it so that
> > it contains lat and lon member values.
> > 
> > 
> > 
> > 
> > 
> > _______________________________________________
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> > 
> > 
> 
>