Polylines is not coming perfectly on google map in ios [duplicate] - google-maps

Question

I am trying to get a polyline on a Google map after getting directions. I want to use the v3_epoly to place markers along a polyline.
I found this post, which worked, but I found it wasn't completely accurate. In the image, the Google directions is the light blue and the polyline is the darker blue:
You can see it's quite inaccurate.
This is the code:
directions_service.route(req, function(response, status) {
if (status == google.maps.DirectionsStatus.OK) {
path = response.routes[0].overview_path;
$(path).each(function(index, item) {
route.getPath().push(item);
bounds.extend(item);
});
route.setMap(map);
map.fitBounds(bounds);
directions_display.setDirections(response);
}
});
Anyone know either how to improve this accuracy or to get the polyline another way?
EDIT:
I wanted to add the code that got it working:
legs = response.routes[0].legs;
$(legs).each(function(index, item) {
steps = item.steps;
$(steps).each(function(index, item) {
path = item.path;
$(path).each(function(index, item) {
route.getPath().push(item);
counter++;
bounds.extend(item);
});
});
});

Answer 1

Don't use overview_path for the polyline, it doesn't include all the points, grab the points out of all the legs and use them to create the polyline.
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);
example
code snippet:
function initialize() {
var map = new google.maps.Map(
document.getElementById("map_canvas"), {
center: new google.maps.LatLng(51.276092, 1.028938),
zoom: 13,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var directionsService = new google.maps.DirectionsService();
var directionsDisplay = new google.maps.DirectionsRenderer({
map: map,
preserveViewport: true
});
directionsService.route({
origin: new google.maps.LatLng(51.269776, 1.061326),
destination: new google.maps.LatLng(51.30118, 0.926486),
waypoints: [{
stopover: false,
location: new google.maps.LatLng(51.263439, 1.03489)
}],
travelMode: google.maps.TravelMode.DRIVING
}, function(response, status) {
if (status === google.maps.DirectionsStatus.OK) {
// directionsDisplay.setDirections(response);
var polyline = new google.maps.Polyline({
path: [],
strokeColor: '#0000FF',
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);
} else {
window.alert('Directions request failed due to ' + status);
}
});
}
google.maps.event.addDomListener(window, "load", initialize);
html,
body,
#map_canvas {
height: 100%;
width: 100%;
margin: 0px;
padding: 0px
}
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
<div id="map_canvas"></div>