Я хотел бы нарисовать полилинию «пройденный путь» по заданному маршруту, используя V3 API карт Google.

Полилинии нужно будет проходить через несколько точек / участков.

В настоящее время я использую DirectionsService, чтобы нарисовать полный маршрут.

Я также использую epolys.js, чтобы получить положение маркера для пройденного расстояния.

Я копирую полный маршрут в новую ломаную линию, но я хотел бы только скопировать маршрут до позиции маркера.

Демо-ссылка:http://codepen.io/1983ron/pen/wKMVQr

И вот где я сейчас с JS

var geocoder;
var map;
var marker;
var gmarkers = [];
var METERS_TO_MILES = 0.000621371192;
var walked = (Math.round(670 * 1609.344));

//ICON
var iconImage = new google.maps.MarkerImage(
    'http://www.ronnieatkinson.co.uk/clients/wc2015/maps/01/mapIcons/marker_red.png',       //MARKER URL
    new google.maps.Size(20, 34),   //MARKER SIZE (WxH)
    new google.maps.Point(0,0),     //MARKER ORIGIN
    new google.maps.Point(9, 34)    //MARKER ANCHOR
);

//SHADOW
var iconShadow = new google.maps.MarkerImage(
    'http://www.google.com/mapfiles/shadow50.png',  //SHADOW URL
    new google.maps.Size(37, 34),                   //SHADOW SIZE (WxH)
    new google.maps.Point(0,0),                     //SHADOW ORIGIN
    new google.maps.Point(9, 34)                    //SHADOW ANCHOR
);

//INFO WINDOW
var infowindow = new google.maps.InfoWindow({ 
    size: new google.maps.Size(150,50)
});

//CREATE MARKER
function createMarker(latlng, label, html) {
    var contentString = '<b>'+label+'</b><br>'+html;
    var marker = new google.maps.Marker({
        position: latlng,
        map: map,
        shadow: iconShadow,
        icon: iconImage,
        title: label,
        zIndex: Math.round(latlng.lat()*-100000)<<5
    });

    marker.myname = label;
    gmarkers.push(marker);

    google.maps.event.addListener(marker, 'click', function() {
        infowindow.setContent(contentString); 
        infowindow.open(map,marker);
    });
    return marker;
}

function initialize() {
    var latlng = new google.maps.LatLng(51.555967, -0.279736);
    var myOptions = {
        zoom: 9,
        center: latlng,
        mapTypeId: google.maps.MapTypeId.TERRAIN
    };

    map = new google.maps.Map(document.getElementById("map"), myOptions);

    var rendererOptions = {
        map: map,
        suppressMarkers: true,
    };

    directionsDisplay = new google.maps.DirectionsRenderer(rendererOptions);

    //Edinburgh to Eden Project
    var point1 = new google.maps.LatLng(58.981386, -2.973751); //Orkney Rugby Football Club
    var point2 = new google.maps.LatLng(55.881517, -4.342057); //Scotstoun Stadium
    var point3 = new google.maps.LatLng(54.998080, -7.319812); //Guildhall St
    var point4 = new google.maps.LatLng(54.563716, -5.942729); //Belfast Harlequins RFC
    var point5 = new google.maps.LatLng(53.271057, -9.054253); //Hotel Spanish Arch
    var point6 = new google.maps.LatLng(52.674222, -8.642515); //Thomond Park
    var point7 = new google.maps.LatLng(53.291755, -3.713769); //Colwyn Leisure Centre
    var point8 = new google.maps.LatLng(51.748180, -3.618567); //Glynneath Rugby Football Club

    var wps = [
        { location: point1 },
        { location: point2 },
        { location: point3 },
        { location: point4 },
        { location: point5 },
        { location: point6 },
        { location: point7 },
        { location: point8 }
    ];

    //START
    var org = new google.maps.LatLng (55.945315, -3.205309); //EDINBURGH 

    //FINISH
    var dest = new google.maps.LatLng (50.360130, -4.744717); //EDEN PROJECT

    var request = {
        origin: org,
        destination: dest,
        waypoints: wps,
        travelMode: google.maps.DirectionsTravelMode.WALKING,
        //unitSystem: google.maps.UnitSystem.IMPERIAL
    };

    directionsService = new google.maps.DirectionsService();
    directionsService.route(request, function(response, status) {
        if (status == google.maps.DirectionsStatus.OK) {
            //SHOW ROUTE
            directionsDisplay.setDirections(response);

            //COPY POLY FROM DIRECTION SERVICE
            var polyline = new google.maps.Polyline({
                path: [],
                strokeColor: '#FF0000',
                strokeWeight: 3
            });

            var bounds = new google.maps.LatLngBounds();
            var legs = response.routes[0].legs;
            for (i=0;i<legs.length;i++) {
                var steps = legs[i].steps;
                for (j=0;j<steps.length;j++) {
                    var nextSegment = steps[j].path;
                    for (k=0;k<nextSegment.length;k++) {
                        polyline.getPath().push(nextSegment[k]);
                        bounds.extend(nextSegment[k]);
                    }
                }
            }

            polyline.setMap(map);
            map.fitBounds(bounds);

            //alert(walked);

            //ADD MARKER TO NEW POLYLINE AT 'X' DISTANCE
            createMarker(polyline.GetPointAtDistance(walked), "You are here", (Math.round( walked * METERS_TO_MILES * 10 ) / 10)+' miles');

            //GET THE TOTAL DISTANCE
            var distance= 0;
            //var METERS_TO_MILES = 0.000621371192;
            for(i = 0; i < response.routes[0].legs.length; i++){
                //FOR EACH LEG GET THE DISTANCE AND ADD IT TO THE TOTAL
                distance += parseFloat(response.routes[0].legs[i].distance.value);
            }
            //alert((Math.round( distance * METERS_TO_MILES * 10 ) / 10)+' miles');
            //alert(distance); //METERS

        } else if(status == google.maps.DirectionsStatus.MAX_WAYPOINTS_EXCEEDED){
            alert ('Max waypoints exceeded');
        } else {
            alert ('failed to get directions');
        }
    });
};window.onload = function() { initialize(); };

Любая помощь будет оценена.