using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
/// <summary>
/// 綁定到搖桿上的搖桿類,參考半徑50
/// </summary>
public class Rocker : MonoBehaviour {

  Vector2 m_offet;//偏移向量
  Vector2 m_originalPos;//搖桿原始屏幕坐標(biāo)
  Touch[] touches;//屏幕上觸控點(diǎn)數(shù)組
  int touch_Id = -1;//觸控點(diǎn)數(shù)組下標(biāo)
  bool isMove = false;//是否移動(dòng)
  float m_ScreenScale;
  /// <summary>
  /// 給外部調(diào)用的偏移向量,告知搖桿參數(shù)
  /// </summary>
  public Vector3 Offet
  {
    get
    {
      return m_offet;
    }
  }

  // Use this for initialization
  void Start () {

    m_originalPos = transform.position;//搖桿中心的屏幕坐標(biāo)位置
    m_ScreenScale = Screen.width / 800f;
  }

  // Update is called once per frame
  void Update () {
    //得到屏幕觸控?cái)?shù)組
    touches = Input.touches;
    if (touches.Length > 0)//如果觸點(diǎn)開啟
    {
      //得到離搖桿中心最近的觸點(diǎn)下標(biāo) touch_Id;
      if (touches.Length == 1)//只有一個(gè)觸點(diǎn)時(shí)
      {
        touch_Id = 0;
      }
      else if (touches.Length > 1)//觸點(diǎn)大于1個(gè)時(shí)
      {
        touch_Id = 0;//先假設(shè)下標(biāo)為0
        for (int i = 1; i < touches.Length; i++)//遍歷觸點(diǎn)數(shù)組
        {
          if (Vector2.SqrMagnitude(touches[i].position - m_originalPos) < Vector2.SqrMagnitude(touches[touch_Id].position - m_originalPos))//第i個(gè)點(diǎn)比假設(shè)的點(diǎn)近
          {
            touch_Id = i;//假設(shè)的點(diǎn)改為第i個(gè)點(diǎn)
          }
        }

      }

      //如果得到的觸點(diǎn)不是取消或抬起
      if (Input.GetTouch(touch_Id).phase != TouchPhase.Canceled && Input.GetTouch(touch_Id).phase != TouchPhase.Ended)
      {
        //觸點(diǎn)在搖桿范圍內(nèi)
        if(Vector2.SqrMagnitude(touches[touch_Id].position - m_originalPos) <= 50*50 * m_ScreenScale * m_ScreenScale)//50為背景半徑
        {
          isMove = true;//開啟遙控
          //搖桿開始控制,計(jì)算偏移量
          SetOffetIn();
        }
        else if(isMove)//觸點(diǎn)在搖桿范圍外,但是遙控已經(jīng)開啟
        {
          SetOffetOut();
        }
      }
      else// 手指抬起,搖桿回歸原始位置
      {
        transform.position = m_originalPos;
        m_offet = Vector2.zero;
        isMove = false;
        touch_Id = -1;
      }
    }

  }
  /// <summary>
  /// 觸點(diǎn)在操作盤內(nèi)時(shí)
  /// 搖桿控制方法
  /// </summary>
  void SetOffetIn()
  {
    //距離過小視為不偏移搖桿位置不變
    if(Vector2.SqrMagnitude(touches[touch_Id].position - m_originalPos) < 5 * m_ScreenScale)
    {
      GetComponent<Image>().rectTransform.position = m_originalPos;//搖桿定位在原始位置
      m_offet = Vector3.zero;
    }
    else
    {
      //搖桿位置追蹤
      GetComponent<Image>().rectTransform.position = touches[touch_Id].position;
      m_offet = touches[touch_Id].position - m_originalPos;//賦值偏移值
      m_offet = m_offet.normalized;//歸一化
    }
  }
  /// <summary>
  /// 觸點(diǎn)在操作盤外時(shí)
  /// 搖桿控制方法
  /// </summary>
  void SetOffetOut()
  {
    Vector2 tempDir;//臨時(shí)偏移向量
    tempDir = touches[touch_Id].position - m_originalPos;
    //更新?lián)u桿位置:距離原始位置127各單位
    GetComponent<Image>().rectTransform.position = m_originalPos + (tempDir.normalized) * 25*m_ScreenScale;
    //偏移量
    m_offet = tempDir.normalized;//歸一化
  }
  private void OnGUI()
  {
    GUIStyle style = new GUIStyle(); //實(shí)例化一個(gè)新的GUIStyle，名稱為style ，后期使用
    style.fontSize = 50; //字體的大小設(shè)置數(shù)值越大，字越大，默認(rèn)顏色為黑色 
    style.normal.textColor = new Color(1, 1, 1); //設(shè)置文本的顏色為 新的顏色(0,0,0)修改值-代表不同的顏色,值為整數(shù) 我個(gè)人覺得有點(diǎn)像RGB的感覺
    GUI.Label(new Rect(20, 30, 300, 60), "原始位置:" + m_originalPos.ToString(),style);
    GUI.Label(new Rect(20, 100, 300, 60), "搖桿位置:" + GetComponent<Image>().rectTransform.position.ToString(), style);
    GUI.Label(new Rect(20, 170, 300, 60), "觸點(diǎn)位置:" + touches[touch_Id].position.ToString(), style);
    GUI.Label(new Rect(20, 240, 300, 60), "屏幕分辨率:" + Screen.currentResolution, style);


  }
}