Leaflet: panTo Web Mercator coordinates (EPSG 3857)

Question

I have a standard leaflet map showing a tile layer. Now leaflet only lets you use panTo method using LatLng for example,

map.panTo(new L.LatLng(40.17, -98.12));

How will I use above panTo method if my coordinates are in EPSG:3857 for example (3679364.68,-9096106.74) ?

This is quite simple to to in Openlayers as once you define a map projection everything works in that projection. But Leaflet always works on latlng on the outside.

Any simple way to accomplish this using leaflet library?

Thanks!

Answer 1

Leaflet lets you use panTo method by unproject 3857 point. If you don't want to use proj4js library it also achieve in leaflet.

var point = new L.Point(3679364.68,-9096106.74); // Lon/Lat
var earthRadius = 6378137;
var latlng = L.Projection.SphericalMercator.unproject(point.divideBy(earthRadius));

map.panTo(new L.LatLng(latlng.lat, latlng.lng));

Answer 2

I can get it working if I use proj4js library to transform the coordinates by doing this:

var source = new Proj4js.Proj('EPSG:3857');
var dest = new Proj4js.Proj('EPSG:4326');
var p = new Proj4js.Point(-9096106.74,3679364.68); //this takes x,y
Proj4js.transform(source, dest, p);
this.map.setView(new L.LatLng(p.y, p.x),zoom);

But this is still not an ideal solution as it taxes me a Megabyte for for including the library. I am still looking for a leaflet solution. Knowing that internally leaflet already uses EPSG:3857 to fetch tiles, this shouldn't be this difficult.

Update

To do this purely in Leaflet, look at @ARsl's answer. Only reason I still accept this as my answer because, still feel uncomfortable doing the projection calculations like that (not that they are wrong), and just for that reason I don't accept this answer. Plus proj4js as added advantages of supporting many more datums.