Joystick

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

public class Joystick : MonoBehaviour, IDragHandler
{
    Vector2 startPos;
    public Canvas canvas;
    public float Radius;
    public Vector2 Axis;

    private void Start()
    {
        startPos = this.transform.position;
    }

    public Vector2 axis
    {
        get
        {
            return Axis;
        }
    }

    public float Horizontal
    {
        get
        {
            return Axis.x;
        }
    }

    public float Vertical
    {
        get
        {
            return Axis.y;
        }
    }

    public bool isMoving
    {
        get
        {
            return Axis != Vector2.zero;
        }
    }

    public void OnDrag (PointerEventData data)
    {
        Vector2 pos;

        RectTransformUtility.ScreenPointToLocalPointInRectangle (canvas.transform as RectTransform, Input.mousePosition, canvas.worldCamera, out pos);
        Vector2 newpos = this.transform.position = canvas.transform.TransformPoint (pos) - (Vector3)startPos;
        newpos.x = Mathf.Clamp(newpos.x, -Radius, Radius);
        newpos.y = Mathf.Clamp(newpos.y, -Radius, Radius);

        Axis = pos / Radius;

        this.transform.localPosition = newpos;
    }


    public void OnMouseUp()
    {
        this.transform.localPosition = startPos;
        Axis = Vector2.zero;
    }
}