title: Direction api: check if a place falls in the route path between 2 places
body: <p>I am using Google Direction API to plot the route path between 2 places A and B. I am able to do this. Now, I have a requirement to check if given a place C falls in the route path of A and B. </p>
  
  <p>Here is the snapshot of the route path that I have generated from my code.</p>
  
  <p><img src="https://i.stack.imgur.com/I6dUg.png" alt="Route map between A and B"></p>
  
  <p>Here is the corresponding code:</p>
  
  <pre><code>function initialize() {
                  var input = document.getElementById('searchTextFieldSource');
                  var input1 = document.getElementById('searchTextFieldDestination');
  
                  var autocomplete = new google.maps.places.Autocomplete(input);
                  var autocomplete1 = new google.maps.places.Autocomplete(input1);
                  google.maps.event.addListener(autocomplete1, 'place_changed', function () {
                      var place = autocomplete.getPlace();
                      document.getElementById('city1').value = place.name;
                      var place1Lat = place.geometry.location.lat();
                      var place1Lng = place.geometry.location.lng();
                      document.getElementById('cityLat1').value = place1Lat;
                      document.getElementById('cityLng1').value = place1Lng;
  
                      var obj = new Object();
                      obj.city =place.name;
                      obj.latitude = place.geometry.location.lat();
                      obj.longitude = place.geometry.location.lng();
                      locations.push(obj);
  
  
                      var place2 = autocomplete1.getPlace();
                      document.getElementById('city2').value = place2.name;
                      var place2Lat = place2.geometry.location.lat();
                      var place2Lng = place2.geometry.location.lng();
                      document.getElementById('cityLat2').value = place2Lat;
                      document.getElementById('cityLng2').value = place2Lng;
  
                      var obj = new Object();
                      obj.city = place2.name;
                      obj.latitude = place2.geometry.location.lat();
                      obj.longitude = place2.geometry.location.lng();
                      locations.push(obj);
  
                      directionsDisplay = new google.maps.DirectionsRenderer();
                      var startPlace = new google.maps.LatLng(place1Lat, place1Lng);
  
                      var mapOptions = {
                          zoom:7,
                          center: startPlace
                      }
  
                      var map = new google.maps.Map(document.getElementById('map'), mapOptions);
                      directionsDisplay.setMap(map);
                      //refreshMap(locations);
  
                      var start = $("#city1").val();
                      var end = $("#city2").val();
                      var request = {
                            origin:start,
                            destination:end,
                            travelMode: google.maps.TravelMode.DRIVING
                      };
                      directionsService.route(request, function(response, status) {
                          if (status == google.maps.DirectionsStatus.OK) {
                            directionsDisplay.setDirections(response);
                          }
                      });
                  });
              }
  </code></pre>
  
  <p>How can I go about it?</p>