convert coords from google maps to bing maps

google-to-bing-maps.js

// Believe it or not, Microsoft has this documented:
// http://msdn.microsoft.com/en-us/library/bb259689.aspx
function toBing(x, y, zoom) {

  var x2 = pad(String(x.toString(2)), zoom + 1)
    , y2 = pad(String(y.toString(2)), zoom + 1)
    , quadkey = ''
    ;
  
  function pad(n, p) {
    while (n.length < p) {
      n = '0' + n;
    }
    return n;
  }

  for (var i = 0; i < y2.length; i += 1) {
    quadkey += (y2[i] + x2[i]);
  }

  // ensure that the number is positive (not two's complement)
  quadkey = parseInt('0' + quadkey, 2);

  // t0-t3
  return "http://ecn.t3.tiles.virtualearth.net/tiles/"
    + "a"
    + pad(quadkey.toString(4), zoom)
    + ".jpeg?g=915&mkt=en-us&n=z"
    ;
}

toBing(1555, 3095, 13);

google-to-yahoo-maps.js

/*
  Easy as pie

  http://khm1.google.com/kh/v=108&src=app&x=24883&s=&y=49498&z=17&s=Gal

  http://3.maptile.lbs.ovi.com/maptiler/v2/maptile/279af375be/satellite.day/17/24883/49498/256/jpg?lg=ENG&token=TrLJuXVK62IQk0vuXFzaig%3D%3D&requestid=yahoo.prod&app_id=eAdkWGYRoc4RfxVo0Z4B
 */

// actually Nokia
function toYahoo(x, y, zoom) {
  return "http://4.maptile.lbs.ovi.com/maptiler/v2/maptile/279af375be/satellite.day/"
    + zoom
    + "/"
    + x
    + "/"
    + y
    + "/256/jpg?lg=ENG&token=TrLJuXVK62IQk0vuXFzaig%3D%3D&requestid=yahoo.prod&app_id=eAdkWGYRoc4RfxVo0Z4B"
}

// png8 vs jpeg... why?
function toNokia(x, y, zoom) {
  return "http://4.maptile.lbs.ovi.com/maptiler/v2/maptile/4176ef2b30/satellite.day/"
    + zoom
    + "/"
    + x
    + "/"
    + y
    + "/256/png8?token=fee2f2a877fd4a429f17207a57658582&appId=nokiaMaps"
}

toYahoo(24884, 49498, 17);

/*
 At first I thought it wasn't working because I was using the 45º images, which have a different y scale:
 http://khmdb1.google.com/kh?v=53&src=app&x=24883&s=&y=54195&z=17&s=Gali&deg=0
*/

to-google.js

  strategies.google = (function () {
    var j = 0
      , galileos = [
            "G"
          , "Ga"
          , "Gal"
          , "Gali"
          , "Galil"
          , "Galile"
          , "Galileo"
        ]
      , numServers = 2
      ;

    return function (tile, i) {
      j = (i || j) % numServers;

      return "http://khm" + (j % 2) + ".google.com/kh/"
        + "v="
        + "108"
        + "&x="
        + tile.x
        + "&y="
        + tile.y
        + "&z="
        + tile.zoom
        + "&s="
        + galileos[j % galileos.length]
        ;
    };
  }());