using UnityEngine;

using UnityEngine.EventSystems;

public class BarGroundMove : MonoBehaviour,IPointerDownHandler, IPointerUpHandler,

    IDragHandler

{ 

    public GameObject rockerOnOff;         //控制摇杆开关

    public GameObject rockerStick;         //摇杆的杆

    public GameObject rockerFather;        //摇杆父对象

    public GameObject rockerControlGo;     //摇杆需要控制的对象

    float radius = ;                     //摇杆的杆，和摇杆底图的距离

    Vector2 dirV2;

    Vector3 dirV3;

    public void OnPointerDown(PointerEventData eventData)  //点击事件的函数 IPointerDownHandler接口生成

    {

        rockerOnOff.SetActive(true);           //点击时候，将摇杆激活

        Vector2 localPos;

        //这个Api：public static bool ScreenPointToLocalPointInRectangle(RectTransform rect, Vector2 screenPoint, Camera cam, out Vector2 localPoint);

        //rockerFather.transform as RectTransform，rockerFather为父类的本地坐标

        //eventData.position这个事件触发的坐标点

        //eventData.pressEventCamera这个事件触发时候的相机

        //out localPos 这个参数就是相对于 RectTransform rect的Vector2坐标

        RectTransformUtility.ScreenPointToLocalPointInRectangle(

            rockerFather.transform as RectTransform,

            eventData.position,

            eventData.pressEventCamera,

            out localPos

        );

        rockerOnOff.transform.localPosition = localPos;  //激活摇杆的位置，就是相对rockerFather的位置

    }

    public void OnDrag(PointerEventData eventData)  //拖拽事件的函数 IDragHandler 接口生成

    {

        Vector2 localPos;                                               //相对于摇杆的拖拽位置

        RectTransformUtility.ScreenPointToLocalPointInRectangle(

            rockerOnOff.transform as RectTransform,

            eventData.position,

            eventData.pressEventCamera,

            out localPos

            );

        Vector2 groundPos;                                             //相对于摇杆父类的拖拽位置

        RectTransformUtility.ScreenPointToLocalPointInRectangle(

        rockerFather.transform as RectTransform,

        eventData.position,

        eventData.pressEventCamera,

        out groundPos

        );

        //得到杆相对摇杆的向量，写全的话是rockerOnOff.transform.localPositio - Vecter2.zero（对于杆，相当于父类摇杆本地坐标是（，））

        Vector2 grV2 = rockerOnOff.transform.localPosition; 

        dirV2 = localPos.normalized;              //这里是记录拖动得到的单位向量，方便下面移动计算计算

        if (localPos.magnitude > radius)    //当长度大于半径的时候，则整个摇杆会跟着杆移动

        {

            rockerOnOff.transform.localPosition = (grV2 - groundPos).normalized * radius + groundPos;

            rockerStick.transform.localPosition = localPos.normalized * radius;

        }

        else

        {

            rockerStick.transform.localPosition = localPos;

        }

    }

    public void OnPointerUp(PointerEventData eventData)  //松开事件的函数  IPointerUpHandler 接口生成

    {

        rockerStick.transform.localPosition = Vector3.zero;

        dirV2 = Vector2.zero;  //这里是抬起时候，将单位向量置0，这样才能使得下面物体也不会根据向量进行移动

        rockerOnOff.SetActive(false);

    }

    void Start()

    {

    }

    void Update()

    {

        dirV3.x = dirV2.x;

        dirV3.z = dirV2.y;

        dirV3.y = ;

        rockerControlGo.transform.Translate(new Vector3(, , dirV3.magnitude*Time.deltaTime*.5f));

        if (dirV3 != Vector3.zero)

        {

            rockerControlGo.transform.rotation = Quaternion.Lerp(rockerControlGo.transform.rotation, Quaternion.LookRotation(dirV3),.05f);

        }

    }

}