[OpenLayers-Dev] Vector layer marker drifting with Google base map

[Sean Gillies]

Thanks, Eric.

Eric Lemoine wrote:
> Hi Sean. You need to use ESPG:900913 and set sphericalMercator to true
> in the options passed to the constructor of the Google layer. There's
> a page on OpenLayers' wiki about this, search SphericalMercator using
> the wiki's search engine. Cheers. Eric
> 
> 2008/9/18, Sean Gillies <sgillies at frii.com>:
>> Hi all,
>>
>> I'm trying to overlay a point vector layer symbolized with drop shadow
>> markers over a base Google layer. Things look fine, the marker is where
>> I expect it, until I pan and then the position of the marker begins to
>> drift approximately half height of the marker in the panning direction.
>> I'm using the javascript served from openlayers.org/api/OpenLayers.js.
>>
>> Known bug? Programmer error? Script below:
>>
>>
>> <script type="text/javascript">
>>   var map, base, marker, coords;
>>   var SHADOW_Z_INDEX = 10;
>>   var MARKER_Z_INDEX = 11;
>>
>>   function init() {
>>     map = new OpenLayers.Map('map');
>>     base = new OpenLayers.Layer.Google(
>>                 "Base", {
>>                     isBaseLayer: true,
>>                     type: G_PHYSICAL_MAP,
>>                     }
>>                 );
>>     marker = new OpenLayers.Layer.Vector(
>>                 "Marker",
>>                 {
>>                     styleMap: new OpenLayers.StyleMap({
>>                         externalGraphic:
>> "http://openlayers.org/dev/img/marker-gold.png",
>>                         backgroundGraphic:
>> "http://openlayers.org/dev/examples/marker_shadow.png",
>>                         backgroundXOffset: 0,
>>                         backgroundYOffset: -7,
>>                         graphicZIndex: MARKER_Z_INDEX,
>>                         backgroundGraphicZIndex: SHADOW_Z_INDEX,
>>                         pointRadius: 10
>>                     }),
>>                     reproject: true,
>>                     isBaseLayer: false,
>>                     projection
>>                     rendererOptions: {yOrdering: true}
>>                 }
>>             );
>>     coords = pleiades_oljs.centroid.coordinates;
>>     map.addLayers([base, marker]);
>>     map.setCenter(new OpenLayers.LonLat(coords[0], coords[1]), 5);
>>     marker.features.push(
>>                     new OpenLayers.Feature.Vector(
>>                         new OpenLayers.Geometry.Point(coords[0], coords[1])
>>                     )
>>                 );
>>   }
>> </script>
>>
>> I'm grateful for any suggestions.
>>
>> Sean
>> _______________________________________________
>> Dev mailing list
>> Dev at openlayers.org
>> http://openlayers.org/mailman/listinfo/dev
>>
>