using UnityEngine;
using System.Collections;
using UnityEngine.UI;public class AugmentedScript : MonoBehaviour
{private float originalLatitude;private float originalLongitude;private float currentLongitude;private float currentLatitude;private GameObject distanceTextObject;private double distance;private bool setOriginalValues = true;private Vector3 targetPosition;private Vector3 originalPosition;private float speed = .1f;IEnumerator GetCoordinates(){// update/get device's gps coordinates}
public void Calc(float lat1, float lon1, float lat2, float lon2){// calculates distance between two sets of coordinates, taking into account the curvature of the earth}void Start(){// initialization}void Update(){// update each frame}
}

void Start(){// get the reference to UIText distance to get the user gps coordinatesdistanceTextObject = GameObject.FindGameObjectWithTag ("distanceText");// keep getting the gps coordinates from the phoneStartCoroutine ("GetCoordinates");// initialize target and original position, transform refers to the flying disktargetPosition = transform.position;originalPosition = transform.position;
}

void Update(){// linearly interpolate from current position to target positiontransform.position = Vector3.Lerp(transform.position, targetPosition, speed);// rotate by 1 degree about the y axis every frametransform.eulerAngles += new Vector3 (0, 1f, 0);
}

Vector3.Lerp(): https://docs.unity3d.com/ScriptReference/Vector3.Lerp.html

public static Vector3 Lerp(Vector3 a, Vector3 b, float t)

Linearly interpolates between the vectors a and b by the interpolant t (t = [0,1])


When t = 0 returns a. When t = 1 returns b. When t = 0.5 returns the point midway between a and b.

IEnumerator GetCoordinates()
{// while true so this function keeps running once started.while (true) {// code from LocationService.Start documentation sample // https://docs.unity3d.com/ScriptReference/LocationService.Start.html// check if user has location service enabledif (!Input.location.isEnabledByUser)yield break;// Start service before querying location
        Input.location.Start (1f, 0.1f);// Wait until service initializesint maxWait = 20;while (Input.location.status == LocationServiceStatus.Initializing && maxWait > 0) {yield return new WaitForSeconds (1);maxWait--;}// Service didn't initialize in 20 secondsif (maxWait < 1) {print ("Timed out");yield break;}// Connection has failedif (Input.location.status == LocationServiceStatus.Failed) {print ("Unable to determine device location");yield break;} else {// start doing the device's coordinates processing// Access granted and location value could be retrievedprint ("Location: " + Input.location.lastData.latitude + " " + Input.location.lastData.longitude + " " + Input.location.lastData.altitude + " " + Input.location.lastData.horizontalAccuracy + " " + Input.location.lastData.timestamp);// if original value has not yet been set, then save player's coordinates when app startsif (setOriginalValues) {// "private bool setOriginalValues = true;" at the start originalLatitude = Input.location.lastData.latitude;originalLongitude = Input.location.lastData.longitude;setOriginalValues = false;}//overwrite current lat and lon everytimecurrentLatitude = Input.location.lastData.latitude;currentLongitude = Input.location.lastData.longitude;//calculate the distance between where the player was when the app started and where they are now.
            Calc (originalLatitude, originalLongitude, currentLatitude, currentLongitude);}Input.location.Stop();}
}

public void Calc(float lat1, float lon1, float lat2, float lon2)
{var R = 6378.137; // Radius of earth in KMvar dLat = lat2 * Mathf.PI / 180 - lat1 * Mathf.PI / 180;var dLon = lon2 * Mathf.PI / 180 - lon1 * Mathf.PI / 180;float a = Mathf.Sin(dLat / 2) * Mathf.Sin(dLat / 2) + Mathf.Cos(lat1 * Mathf.PI / 180) * Mathf.Cos(lat2 * Mathf.PI / 180) * Mathf.Sin(dLon / 2) * Mathf.Sin(dLon / 2);var c = 2 * Mathf.Atan2(Mathf.Sqrt(a), Mathf.Sqrt(1 - a));distance = R * c;distance = distance * 1000f; // meters//set the distance text on the canvasdistanceTextObject.GetComponent<Text> ().text = "Distance: " + distance;//convert distance from double to floatfloat distanceFloat = (float)distance;//set the target position of the ufo, this is where we lerp to in the update functiontargetPosition = originalPosition - new Vector3 (0, 0, distanceFloat * 12);//distance was multiplied by 12 so I didn't have to walk that far to get the UFO to show up closer
}    

if (!Input.location.isEnabledByUser) yield break;