[OpenLayers-Users] Referencing Kamap a Tile

[Ben Brehmer]

Christopher Schmidt wrote:
> On Thu, Jan 25, 2007 at 04:36:05PM -0800, Ben Brehmer wrote:
>   
>> I have a Kamap Layer and I need to be able to reference the tile 
>> associated with a viewport pixel. I don't know if this is possible, but 
>> I want to retrieve the tile that lies underneath a certain pixel 
>> position within the viewport.
>>     
>
> Right click? :)
>
> More seriously, you can get the geographic location from
> getLonLatFromPixel or something similar on the Map object, and then look
> at the KaMap getURL function:
>     getURL: function (bounds) {
>         var mapRes = this.map.getResolution();
>         var scale = Math.round((this.map.getScale() * 10000)) / 10000;        
>         var cellSize = new OpenLayers.Size(mapRes*this.tileSize.w,
>                                            mapRes*this.tileSize.h);
>         var pX = Math.round(((bounds.left) / cellSize.w) *
>                             this.tileSize.w);
>         var pY = -Math.round(((bounds.top) / cellSize.h) *
>                               this.tileSize.h);
>         return this.getFullRequestString(
>                       { t: pY, 
>                         l: pX,
>                         s: scale
>                       });
>     },
>
> Something like this ought  used with px.lon, px.lat instead of
> bounds.left, bounds.top might get you there, modulo some rounding
> issues. Give it a shot? 
>
> Regards,
>   
mmmm, yes that would work....and right clicking the tile is not quite 
what I need :)

But what I want to do, is reference the top and left attributes of a 
tile that is already loaded, with the reference being made from a click 
event in the viewport (from which I can retrieve the pixel or lon/lat).

Thanks,

Ben