[OpenLayers-Dev] singleTile and Google Maps error

Mon Mar 30 14:56:30 EDT 2009

Hi,

I have a problem with a singleTile WMS layer above Google Maps. I wanted 
to check to see if anyone has seen it before or if there's a already a 
ticket that I missed before investigating further.

The problem is when combining a google layer with a singleTile overlay, 
when looking at the whole world, the overlay is displayed on the 
right-hand side of the map and not in the current view. Sometimes it's 
even way off the map.

 From what I understood, OL tries to place the layer at the right place, 
but the top-right coordinates it gets go behond the dateline and get 
shifted to the right. Here's an example to reproduce:

<html xmlns="http://www.w3.org/1999/xhtml">
   <head>
     <script src="/openlayers/openlayers/lib/OpenLayers.js"></script>
     <script 
src='http://maps.google.com/maps?file=api&amp;v=2&amp;key=ABQIAAAACCFvpt30gpRs1CNZ1gCc_RTBfUk9TZrBRaIteybtnU2KziHEpRQjbtlKJwRisyazNeb0Lj9_OfGlMA'></script>
     <script type="text/javascript">
         var map, options;
         function init()
         {

     var maxBounds = new OpenLayers.Bounds(-20000000, -8000000, 
20000000, 15000000);
             var options = {
                 projection: new OpenLayers.Projection("EPSG:900913"),
                 displayProjection: new OpenLayers.Projection("EPSG:4326"),
                 units: "m",
                 numZoomLevels: 19,
                 minScale: 120000000,
                 maxExtent: maxBounds
             };
             map = new OpenLayers.Map('map', options);

             // create Google Mercator layers
             var gmap = new OpenLayers.Layer.Google(
                 "Google Streets",
                 {'sphericalMercator': true}
             );

             // create WMS layer
             var wms = new OpenLayers.Layer.WMS(
                 "World Map",
         "http://labs.metacarta.com/wms/vmap0",
                 {'layers': 'basic'},
                 {
                     'opacity': 0.7,
                     'isBaseLayer': false,singleTile:true
                 }
             );

             map.addLayers([gmap, wms]);
             map.zoomToMaxExtent();

}

     </script>
   </head>
   <body onload="init()">

     <div id="map" style="width:550px;height:300px"/>

   </body>
</html>

-- 
Julien-Samuel Lacroix
Mapgears
http://www.mapgears.com/