Google Maps for AngularJS Directions Service Draggable

<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&key=xxxxxxxxxxxxxxxxxx&sensor=false"></script>
<script type='text/javascript' src='http://www.example.com/wp/wp-content/themes/ang/js/underscore-min.js'></script>
<script type='text/javascript' src='http://www.example.com/wp/wp-content/themes/ang/js/angular-google-maps.min.js'></script>
<script type='text/javascript' src='http://www.example.com/wp/wp-content/themes/ang/js/app.js'></script>
<div ng-controller="MyCtrl">
  <div class="row">
    <div class="col-sm-6">
      <google-map 
        id="map-canvas"
        center="map.center"
        zoom="map.zoom"
        draggable="true"
        options="map.options"
        control="map.control"
      >
      </google-map>
    </div>
    <div class="col-sm-6">
      <form class="form-horizontal" role="form">
        <div class="form-group">
          <label class="col-sm-4 control-label">Start</label>
          <div class="col-sm-8">
            <select class="form-control" ng-model="routePoints.start" 
                    ng-options="route.name for route in map.routes.start">
            </select>
          </div>
        </div>
<i>(Ctrl-Click for multiple selection)</i> <br>
        <div class="form-group">
          <label class="col-sm-4 control-label">WayPoints</label>
          <div class="col-sm-8">
            <select multiple class="form-control" ng-model="routePoints.ways" 
                    ng-options="route.name for route in map.routes.ways">
            </select>
          </div>
        </div>
        <div class="form-group">
          <label class="col-sm-4 control-label">End</label>
          <div class="col-sm-8">
            <select class="form-control" ng-model="routePoints.end" 
                    ng-options="route.name for route in map.routes.end">
            </select>
          </div>
        </div>
        <button ng-click="calcRoute(routePoints)" type="submit" class="btn btn-default">Submit</button>
      </form>
      <li ng-repeat="route in routesDisplay">
      Route{{route.title}<br />From：{{route.start}<br />To：{{route.end}<br />Distance：{{route.distance}
<br /><br />
      </li>
      <li>Total Distance：{{map.total}</li>
    </div>
  </div>
</div>

var mapApp = angular.module('googleMapApp', ['google-maps','ui.bootstrap']);

mapApp.controller("MyCtrl", function ($scope) {

  angular.extend($scope, {
    map: {
      center: {
        latitude: 35.681382,
        longitude: 139.766084
      },
      options: {
        maxZoom: 20,
        minZoom: 3
      },
      zoom: 15,
      control: {},
      total: {},
      routes: {
        start: [
          {name:'Tokyo Station', latlng:'35.6813177190391,139.76609230041504'},
          {name:'Ootemathi Station', latlng:'35.684228393108306,139.76293802261353'}
        ],
        ways: [
          {name:'Ootemon', latlng:'35.68567497604782,139.7612428665161'},
          {name:'Nijyubashi', latlng:'35.67947017023017,139.75772380828857'},
          {name:'Tokyo Tower', latlng:'日本, 東京都港区芝公園４-２-８'},
          {name:'Hama-rikyu Gardens', latlng:'日本, 東京都中央区浜離宮庭園１-1'}
        ],
        end: [
          {name:'Tokyo Station', latlng:'35.6813177190391,139.76609230041504'},
          {name:'Ootemathi Station', latlng:'35.684228393108306,139.76293802261353'}
        ]
      }
    },
    routePoints: {
      start: {},
      end: {}
    },
    routesDisplay: []
  });
  $scope.routePoints.start = $scope.map.routes.start[0];
  $scope.routePoints.end = $scope.map.routes.end[1];

  var rendererOptions = {
    draggable: true
  };
  var directionsDisplay = new google.maps.DirectionsRenderer(rendererOptions);

  function computeTotalDistance(result) {
    var total = 0;
    var myroutesDisplay = [];
    var myroute = result.routes[0];
    for (var i = 0; i