using UnityEngine;using UnityEngine.UI; public class LuckyTurntable : MonoBehaviour{ public enum State {  None,  //待機狀態  Start,  //加速階段  Prepared, //等待數據階段  End,  //減速階段 }  public delegate void OnFinishCallback(); private event OnFinishCallback OnFinish;  /// <summary> /// 設置完成時的回調 /// </summary> /// <param name="onFinish"></param> public void SetOnFinishCallback(OnFinishCallback onFinish) {  OnFinish += onFinish; }  /// <summary> /// 最大速度 /// </summary> public int velocity = 3000;  public Transform node; public Button btnStart; public Button btnStop; public Button btnRandom; public InputField input;  private State _state; /// <summary> /// 轉盤的狀態 /// </summary> public State CurState {  get  {   return _state;  }  private set  {   _state = value;   switch (value)   {    //不同階段限制各按鈕的點擊狀態    case State.None:     btnStart.enabled = true;     btnStop.enabled = false;     btnRandom.enabled = false;     break;    case State.Start:     btnStart.enabled = false;     btnStop.enabled = true;     btnRandom.enabled = true;     break;    case State.Prepared:    case State.End:     btnStart.enabled = false;     btnStop.enabled = false;     btnRandom.enabled = false;     break;   }  } }  private float _endAngle = 0f; /// <summary> /// 最終停止的角度[0, 360] /// </summary> public float EndAngle {  get  {   return _endAngle;  }  set  {   _endAngle = Mathf.Abs(value);   print("End Angle: " + value);   _endAngle = _endAngle % 360; //將角度限定在[0, 360]這個區間   _endAngle = -_endAngle - 360 * 2; //多N圈并取反，圈數能使減速階段變得更長，顯示更自然，逼真  } }  /// <summary> /// 加速持續時間 /// </summary> private readonly float AcceleateTime = 1f;  /// <summary> /// 減速前的最短持續時間 /// </summary> private float _minTime = 3.0f; /// <summary> /// 角度緩存 /// </summary> private float _tmpAngle = 0f; /// <summary> /// 時間統計 /// </summary> private float _time; /// <summary> /// 速度變化因子 /// </summary> private float _factor;  private void Start() {  CurState = State.None;  btnStart.onClick.AddListener(OnStartClick);  btnStop.onClick.AddListener(OnStopClick);  btnRandom.onClick.AddListener(OnRandomClick); }  private void Update() {  if (CurState == State.None)   return;   _time += Time.deltaTime;  if (CurState == State.End)  {   //通過差值運算實現精準地旋轉到指定角度（球型插值無法實現大于360°的計算）   float k = 2f; //如果嫌減速太慢，可以加個系數修正一下   _tmpAngle = Mathf.Lerp(_tmpAngle, EndAngle, Time.deltaTime * k);    //這里只存在一個方向的旋轉，所以不存在歐拉角萬向節的問題，所以使用歐拉角和四元數直接賦值都是可以的   node.rotation = Quaternion.Euler(0, 0, _tmpAngle);   //node.eulerAngles = new Vector3(0, 0, _tmpAngle);    if (1 >= Mathf.Abs(_tmpAngle - EndAngle))   {    CurState = State.None;    if (null != OnFinish)    {     OnFinish();     OnFinish = null;    }   }  }  else  {   //利用一個速度因子實現變加速的過程   _factor = _time / AcceleateTime;   _factor = _factor > 1 ? 1 : _factor;   node.Rotate(Vector3.back, _factor * velocity * Time.deltaTime, Space.Self);  }   //當收到數據之后并且旋轉了一定時間后開始減速  if (CurState == State.Prepared && _time > _minTime)  {   CurState = State.End;   _tmpAngle = GetCurClockwiseAngle();  } }  /// <summary> /// 將當前指針的歐拉角轉換成順時針統計角度 /// </summary> /// <returns></returns> private float GetCurClockwiseAngle() {  //由于讀取到的值是[0, 180] U [-180, 0]，左邊由0至180遞增，右邊由180轉變成-180，然后遞增至0，所以需要轉相應的轉換  return (-1) * (360 - node.eulerAngles.z) % 360; }  private void OnStartClick() {  CurState = State.Start;  _time = 0; }  /// <summary> /// 讀取輸入框中的角度并停止 /// </summary> private void OnStopClick() {  try  {   EndAngle = float.Parse(input.text);  }  catch  {   EndAngle = 0f;  }  CurState = State.Prepared;  }  /// <summary> /// 隨機一個角度并停止 /// </summary> private void OnRandomClick() {  EndAngle = UnityEngine.Random.Range(0f, 360f);  CurState = State.Prepared; }}