Tile Access for Google Maps and other World Tile UIs

[pramsey]

Using Mapserver to render data for use within alternate mapping systems is a growing use case. A new access API could allow Google Maps users to overlay Mapserver data very simply and accurately. Like the WMS API, the GMaps API will allow users to have a simple install'n'run option for serving data to a de facto standard user interface.

 http://host/cgi-bin/mapserv?map=/the.map&layers=foo,bar&mode=tile&tilemode=spheremerc&tile={X}+{Y}+{Z}

[pramsey]

Proof of concept patch

[pramsey]

Use with GMaps API thusly:

 if (GBrowserIsCompatible()) {
   var myLayer = new GTileLayer(null,null,null,{
                tileUrlTemplate:'http://localhost/cgi-bin/mapserv?map=/your/map.map&mode=tile&layers=continent&tilemode=spheremerc&tile={X}+{Y}+{Z}',
                isPng:true,
                opacity:0.5 });
   var map = new GMap2(document.getElementById("map"));
   map.addControl(new GLargeMapControl());
   map.addControl(new GMapTypeControl());
   map.setCenter(new GLatLng(0.0, 0.0), 1);
   map.addOverlay(new GTileLayerOverlay(myLayer));
 }

[pramsey]

Committed as of r7547.