Total distance calculation from LatLng List

Question

Im using dart/flutter and the \'package:latlong/latlong.dart\' to parse a GPX file into a list of LatLng objects. That is working fine, but the next step is to

Answer 1

I've used the vector_math for converting degree to radians and also the geolocator for getting the current user latitude and longitude if in case searching from the current location also there is a method where in you can calculate the distance between two locations directly as Geolocator.distanceBetween(startLatitude, startLongitude, endLatitude, endLongitude).

import 'dart:math' show sin, cos, sqrt, atan2;
import 'package:vector_math/vector_math.dart';
import 'package:geolocator/geolocator.dart';

Position _currentPosition;
double earthRadius = 6371000; 

//Using pLat and pLng as dummy location
double pLat = 22.8965265;   double pLng = 76.2545445; 


//Use Geolocator to find the current location(latitude & longitude)
getUserLocation() async {
   _currentPosition = await GeoLocator.getCurrentPosition(desiredAccuracy: LocationAccuracy.high);
}

//Calculating the distance between two points without Geolocator plugin
getDistance(){
   var dLat = radians(pLat - _currentPosition.latitude);
   var dLng = radians(pLng - _currentPosition.longitude);
   var a = sin(dLat/2) * sin(dLat/2) + cos(radians(_currentPosition.latitude)) 
           * cos(radians(pLat)) * sin(dLng/2) * sin(dLng/2);
   var c = 2 * atan2(sqrt(a), sqrt(1-a));
   var d = earthRadius * c;
   print(d); //d is the distance in meters
}

//Calculating the distance between two points with Geolocator plugin
getDistance(){
   final double distance = Geolocator.distanceBetween(pLat, pLng, 
           _currentPosition.latitude, _currentPosition.longitude); 
   print(distance);
}