Joystick

using System;
using UnityEngine;
using UnityEngine.EventSystems;

namespace UnityStandardAssets.CrossPlatformInput
{
    public class Joystick : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IDragHandler{
        public enum AxisOption{
            Both,
            OnlyHorizontal,
            OnlyVertical
        }

        public int MovementRange = 100;
        public AxisOption axesToUse = AxisOption.Both; // The options for the axes that the still will use
        public string horizontalAxisName = "Horizontal"; // The name given to the horizontal axis for the cross platform input
        public string verticalAxisName = "Vertical"; // The name given to the vertical axis for the cross platform input

        Vector3 m_StartPos;
        bool m_UseX;
        bool m_UseY;
        CrossPlatformInputManager.VirtualAxis m_HorizontalVirtualAxis;
        CrossPlatformInputManager.VirtualAxis m_VerticalVirtualAxis;

        void Start(){
            m_StartPos = transform.position;
            CreateVirtualAxes();
        }

        void UpdateVirtualAxes(Vector3 value){
            var delta = m_StartPos - value;
            delta.y = -delta.y;
            delta /= MovementRange;
            if (m_UseX)
            {
                m_HorizontalVirtualAxis.Update(-delta.x);
            }

            if (m_UseY)
            {
                m_VerticalVirtualAxis.Update(delta.y);
            }
        }

        void CreateVirtualAxes(){
            m_UseX = (axesToUse == AxisOption.Both || axesToUse == AxisOption.OnlyHorizontal);
            m_UseY = (axesToUse == AxisOption.Both || axesToUse == AxisOption.OnlyVertical);

            if (m_UseX)
            {
                m_HorizontalVirtualAxis = new CrossPlatformInputManager.VirtualAxis(horizontalAxisName);
                CrossPlatformInputManager.RegisterVirtualAxis(m_HorizontalVirtualAxis);
            }
            if (m_UseY)
            {
                m_VerticalVirtualAxis = new CrossPlatformInputManager.VirtualAxis(verticalAxisName);
                CrossPlatformInputManager.RegisterVirtualAxis(m_VerticalVirtualAxis);
            }
        }


        public void OnDrag(PointerEventData data)
        {
            Vector3 newPos = Vector3.zero;

            if (m_UseX)
            {
                int delta = (int)(data.position.x - m_StartPos.x);
                newPos.x = delta;
            }

            if (m_UseY)
            {
                int delta = (int)(data.position.y - m_StartPos.y);
                newPos.y = delta;
            }
            transform.position = Vector3.ClampMagnitude(new Vector3(newPos.x, newPos.y, newPos.z), MovementRange) + m_StartPos;
            UpdateVirtualAxes(transform.position);
        }


        public void OnPointerUp(PointerEventData data)
        {
            transform.position = m_StartPos;
            UpdateVirtualAxes(m_StartPos);
        }


        public void OnPointerDown(PointerEventData data) { }

        void OnDisable()
        {
            // remove the joysticks from the cross platform input
            if (m_UseX)
            {
                m_HorizontalVirtualAxis.Remove();
            }
            if (m_UseY)
            {
                m_VerticalVirtualAxis.Remove();
            }
        }
    }
}