this is the third sample of the tiled WMS overlay over the Spherical Mercator, this time over the new Google Map v3. Previsous post talked about overlyaing WMS in OpenLayers (http://blog.sumbera.com/2010/02/17/overlay-wms-on-google-in-openlayers/).
Sample application can be found here: http://www.sumbera.com/lab/GoogleV3/tiledWMSoverlayGoogleV3.htm You can try to run it on your mobile device as well – suprisingly it run very well on my iPhone (sometimes it just crash Safari :), however on the iPad there are some more serious issues that will be hopefuly resolved with new iOS update (JavaScript stops to run).
For the new Google Map v3 you have to do the following :
//Define custom WMS tiled layer
var SLPLayer =
new google.maps.ImageMapType (
{
getTileUrl:
function (coord, zoom) {
var proj = map.getProjection();
var zfactor = Math.pow(2, zoom);
// get Long Lat coordinates
var top = proj.fromPointToLatLng(
new google.maps.Point(coord.x * 256 / zfactor, coord.y * 256 / zfactor) );
var bot = proj.fromPointToLatLng(
new google.maps.Point((coord.x + 1) * 256 / zfactor, (coord.y + 1) * 256 / zfactor));
//corrections for the slight shift of the SLP (mapserver)
var deltaX = 0.0013;
var deltaY = 0.00058;
//create the Bounding box string
var bbox = (top.lng() + deltaX) + "," +(bot.lat() + deltaY) +","
+(bot.lng() + deltaX) +"," +(top.lat() + deltaY);
//base WMS URL
var url =
"http://mapserver-slp.mendelu.cz/cgi-bin/mapserv?map=/var/local/slp/krtinyWMS.map&" ;
url +="&REQUEST=GetMap"; //WMS operation
url +="&SERVICE=WMS"; //WMS service
url +="&VERSION=1.1.1"; //WMS version
url +="&LAYERS=" + "typologie,hm2003"; //WMS layers
url +="&FORMAT=image/png"; //WMS format
url +="&BGCOLOR=0xFFFFFF" ;
url +="&TRANSPARENT=TRUE" ;
url +="&SRS=EPSG:4326"; //set WGS84
url +="&BBOX="+ bbox; // set bounding box
url +="&WIDTH=256"; //tile size in google
url +="&HEIGHT=256" ;
return url; // return URL for the tile
}, //getTileURL
tileSize: new google.maps.Size(256, 256),
isPng: true
});
//add WMS layer
map.overlayMapTypes.push(SLPLayer);