javascript - Jquery Google マップ ユーザーの場所

Question

次のスクリプトがあります。

        var directionDisplay;
$( document ).on( "pageinit", "#calc", function() {

    directionsDisplay = new google.maps.DirectionsRenderer();
    var defaultLatLng = new google.maps.LatLng(34.0983425, -118.3267434);  // Default to Hollywood, CA when no geolocation support
    if ( navigator.geolocation ) {
        function success(pos) {
            // Location found, show map with these coordinates
            drawMap(new google.maps.LatLng(pos.coords.latitude, pos.coords.longitude));
        }
        function fail(error) {
            drawMap(defaultLatLng);  // Failed to find location, show default map
        }
        // Find the users current position.  Cache the location for 5 minutes, timeout after 6 seconds
        navigator.geolocation.getCurrentPosition(success, fail, {maximumAge: 500000, enableHighAccuracy:true, timeout: 6000});
    } else {
        drawMap(defaultLatLng);  // No geolocation support, show default map
    }
    function drawMap(latlng) {
        var myOptions = {
            zoom: 10,
            center: latlng,
            mapTypeId: google.maps.MapTypeId.ROADMAP,
            disableDefaultUI: true
        };

        var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
        // Add an overlay to the map of current lat/lng
        directionsDisplay.setMap(map);
        var marker = new google.maps.Marker({
            position: latlng,
            map: map,
            title: "Greetings!"

        });

    }

});
var directionsService = new google.maps.DirectionsService();

function calcRoute() {
  var start = document.getElementById("start").value;
  var end = document.getElementById("end").value;
  var request = {
    origin:start,
    destination:end,
    travelMode: google.maps.DirectionsTravelMode.DRIVING
  };

  directionsService.route(request, function(response, status) {
    if (status == google.maps.DirectionsStatus.OK) {
      directionsDisplay.setDirections(response);
      var distanceInput = document.getElementById("distance");
      distanceInput.value = response.routes[0].legs[0].distance.value / 1000;

    }
  });
}

この2点間のkmを計算したいのですが、最後が入力値になり、最初がユーザーの地理位置情報になります。そのためのオンラインソリューションが見つかりません。ルート案内サービスの userlocation の Google API 構文は何ですか? 出力が km 単位である必要があります