SwipeListener.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SwipeListener : MonoBehaviour {

    private Vector3 fp;   //First touch position
    private Vector3 lp;   //Last touch position
    public float dragDistance;  //minimum distance for a swipe to be registered
    public SwipeEvents OnLeft;
    public SwipeEvents OnRight;
    public SwipeEvents OnTap;
    void Start()
    {
        dragDistance = Screen.height * 15 / 100; //dragDistance is 15% height of the screen

    }

    void Update()
    {
        if (Input.touchCount == 1) // user is touching the screen with a single touch
        {
            Touch touch = Input.GetTouch(0); // get the touch
            if (touch.phase == TouchPhase.Began) //check for the first touch
            {
                fp = touch.position;
                lp = touch.position;
            }
            else if (touch.phase == TouchPhase.Moved) // update the last position based on where they moved
            {
                lp = touch.position;
            }
            else if (touch.phase == TouchPhase.Ended) //check if the finger is removed from the screen
            {
                lp = touch.position;  //last touch position. Ommitted if you use list

                //Check if drag distance is greater than 20% of the screen height
                if (Mathf.Abs(lp.x - fp.x) > dragDistance || Mathf.Abs(lp.y - fp.y) > dragDistance)
                {//It's a drag
                 //check if the drag is vertical or horizontal
                    if (Mathf.Abs(lp.x - fp.x) > Mathf.Abs(lp.y - fp.y))
                    {   //If the horizontal movement is greater than the vertical movement...
                        if ((lp.x > fp.x))  //If the movement was to the right)
                        {   //Right swipe
                            Debug.Log("Right Swipe");
                            OnRight.Invoke();

                        }
                        else
                        {   //Left swipe
                            Debug.Log("Left Swipe");
                            OnLeft.Invoke();
                        }
                    }
                    else
                    {   //the vertical movement is greater than the horizontal movement
                        if (lp.y > fp.y)  //If the movement was up
                        {   //Up swipe
                            Debug.Log("Up Swipe");
                        }
                        else
                        {   //Down swipe
                            Debug.Log("Down Swipe");
                        }
                    }
                }
                else
                {   //It's a tap as the drag distance is less than 20% of the screen height
                    Debug.Log("Tap");
                    OnTap.Invoke();

                }
            }
        }

        //~~~~~MOUSE TESTING:
        if (Input.GetMouseButtonDown(0)) //check for the first touch
        {
            fp = Input.mousePosition;
            lp = Input.mousePosition;
        }

        else if (Input.GetMouseButtonUp(0)) //check if the finger is removed from the screen
        {
            lp = Input.mousePosition;  //last touch position. Ommitted if you use list

            //Check if drag distance is greater than 20% of the screen height
            if (Mathf.Abs(lp.x - fp.x) > dragDistance || Mathf.Abs(lp.y - fp.y) > dragDistance)
            {//It's a drag
             //check if the drag is vertical or horizontal
                if (Mathf.Abs(lp.x - fp.x) > Mathf.Abs(lp.y - fp.y))
                {   //If the horizontal movement is greater than the vertical movement...
                    if ((lp.x > fp.x))  //If the movement was to the right)
                    {   //Right swipe
                        Debug.Log("Right Swipe");
                        OnRight.Invoke();

                    }
                    else
                    {   //Left swipe
                        Debug.Log("Left Swipe");
                        OnLeft.Invoke();
                    }
                }
                else
                {   //the vertical movement is greater than the horizontal movement
                    if (lp.y > fp.y)  //If the movement was up
                    {   //Up swipe
                        Debug.Log("Up Swipe");
                    }
                    else
                    {   //Down swipe
                        Debug.Log("Down Swipe");
                    }
                }
            }
            else
            {   //It's a tap as the drag distance is less than 20% of the screen height
                Debug.Log("Tap");
                OnTap.Invoke();
            }
        }
    }


}