[OpenLayers-Users] getting tile information for google base map

[Victor.Tey at csiro.au]

Hi,

I am currently stuck on trying to get wms tiles information for google v3 basemap. What I want to retrieve are,

The bounding box of the tile that is clicked on,

The offset distance in pixel between the bounding box and the pixel that has been clicked on.

Using the default kamap as base, this has been achieved using the code below but using google as base map, I seem to be getting strange values. I understand that google uses EPSG:3857 and have transform as required. Please advice the proper way of doing this.

Thanks


getTileInformationForPoint : function(point) {
        var layer = this.map.baseLayer;

        //Get the bounds of the tile that encases point
        var lonLat = new OpenLayers.LonLat(point.getLongitude(), point.getLatitude());
        var viewPortPixel = this.map.getViewPortPxFromLonLat(lonLat);
        var tileBounds = layer.getTileBounds(viewPortPixel);

        var tileOrigin = new OpenLayers.LonLat(tileBounds.left, tileBounds.top);
        var tileOriginPixel = this.map.getViewPortPxFromLonLat(tileOrigin);

        return Ext.create('portal.map.TileInformation', {
            width : this.map.tileSize.w,
            height : this.map.tileSize.h,
            offset : {  //Object - The point location within the tile being queried
                x : Math.floor(viewPortPixel.x - tileOriginPixel.x),  //Number - offset in x direction
                y : Math.floor(viewPortPixel.y - tileOriginPixel.y)   //Number - offset in y direction
            },
            tileBounds : Ext.create('portal.util.BBox', {
                eastBoundLongitude : tileBounds.right,
                westBoundLongitude : tileBounds.left,
                northBoundLatitude : tileBounds.top,
                southBoundLatitude : tileBounds.bottom
            })
        });
    },

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