using UnityEngine;

using System.Collections;

using UnityEngine.EventSystems;

public class JoyController : MonoBehaviour,IDragHandler,IEndDragHandler {

    //摇杆圆盘半径

    public float radius = 75f;

    //摇杆原始位置

    private Vector3 origin;

    //玩家的角色控制器

    private CharacterController player;

    //玩家移动速度

    public float speed = ;

    //声明一个方向向量

    Vector3 dir;

    void Start()

    {

        //获取当前位置

        origin = transform.position;

        //找到主角玩家

        player = GameObject.FindWithTag ("Player").

            GetComponent<CharacterController> ();

    }

    void Update()

    {

        //玩家移动

        player.SimpleMove (new Vector3(dir.x,,dir.y) * speed * Time.deltaTime);

    }

    /// <summary>

    /// 摇杆拖拽中

    /// </summary>

    /// <param name="eventData">Event data.</param>

    public void OnDrag (PointerEventData eventData)

    {

        //计算起点位置与当前鼠标位置的距离

        float distance = Vector3.Distance (origin, Input.mousePosition);

        //求方向向量

        dir = Input.mousePosition - origin;

        //如果拖拽在圆盘范围内

        if (distance <= radius) {

            //摇杆随鼠标移动而移动

            transform.position = Input.mousePosition;

        } else {

            //实际向量

            Vector3 real = dir.normalized * radius;

            //最终摇杆的位置

            transform.position = real + origin;

        }

    }

    /// <summary>

    /// 结束拖拽

    /// </summary>

    /// <param name="eventData">Event data.</param>

    public void OnEndDrag (PointerEventData eventData)

    {

        dir = Vector3.zero;

        //回到初始位置

        transform.position = origin;

    }

}