geodesic map for a single source and multiple destination gmap4 rails -

i new gmaps4 , have tried lot not able find how create geodesic map, if have single source , multiple destination using gmap4 rails.

so far have tried

js

  var locations = [       //starting point "home", , links other locations"//       ['home', 37.774930, -122.419416],       ['location-1', 35.689487, 139.691706],       ['location-2', 48.856614, 2.352222],       ['location-3', -33.867487, 151.206990]     ]      function initmap() {       var mylatlng = {         lat: 12.363,         lng: -131.044       };       var map = new google.maps.map(document.getelementbyid('map'), {         zoom: 3,         maptypeid: google.maps.maptypeid.roadmap,         center: {           lat: 0,           lng: 0         }       });       var markers = [];       var bounds = new google.maps.latlngbounds();       // add markers , infowindows map       (var = 0; < locations.length; i++) {         var marker = new google.maps.marker({           position: new google.maps.latlng(locations[i][1], locations[i][2]),           title: locations[i][0],           map: map         })         markers.push(marker);         bounds.extend(marker.getposition());         if (i > 0) {           var sitepath = new google.maps.polyline({             path: [markers[0].getposition(), marker.getposition()],             geodesic: true,             strokecolor: '#ff0000',             strokeopacity: 1.0,             strokeweight: 2,             map: map           });         }       }       map.fitbounds(bounds);     }     google.maps.event.adddomlistener(window, "load", initmap); 

html

   <div id="map"></div> 

but not able understand how using gmaps4 rails