Unity教學項目Ceator Kit:FPS 源代碼學習筆記（一）Controller類

這是Unity的教學項目Ceator Kit：FPS，可以通過UnityHub進行下載。
項目截圖：

using System;
using System.Collections.Generic;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

[System.Serializable]//序列化
public class AmmoInventoryEntry
{
    [AmmoType]
    public int ammoType;//子彈類型
    public int amount = 0;//子彈數量
}

public class Controller : MonoBehaviour
{
    //Urg that's ugly, maybe find a better way
    public static Controller Instance { get; protected set; }//單例模式

    public Camera MainCamera;//主相機
    public Camera WeaponCamera;//武器相機
    
    public Transform CameraPosition;//相機位置
    public Transform WeaponPosition;//武器位置
    
    public Weapon[] startingWeapons;//開始的武器種類

    //this is only use at start, allow to grant ammo in the inspector. m_AmmoInventory is used during gameplay
    public AmmoInventoryEntry[] startingAmmo;//開始的彈藥數量

    [Header("Control Settings")]//隱藏
    public float MouseSensitivity = 100.0f;//鼠標靈敏度
    public float PlayerSpeed = 5.0f;//玩家速度
    public float RunningSpeed = 7.0f;//奔跑速度
    public float JumpSpeed = 5.0f;//跳躍速度

    [Header("Audio")]
    public RandomPlayer FootstepPlayer;//玩家音效控制
    public AudioClip JumpingAudioCLip;//跳躍音效
    public AudioClip LandingAudioClip;//走路音效
    
    float m_VerticalSpeed = 0.0f;//垂直速度
    bool m_IsPaused = false;//是否按下
    int m_CurrentWeapon;//當前武器
    
    float m_VerticalAngle, m_HorizontalAngle;//垂直角度，水平角度
    public float Speed { get; private set; } = 0.0f;//速度

    public bool LockControl { get; set; }//鎖定控制，就沒法操作
    public bool CanPause { get; set; } = true;//可以按下

    public bool Grounded => m_Grounded;//是否在地面上 =>goes to

    CharacterController m_CharacterController;//玩家控制器

    bool m_Grounded;
    float m_GroundedTimer;//地面記錄時間
    float m_SpeedAtJump = 0.0f;//在跳躍時的速度

    List<Weapon> m_Weapons = new List<Weapon>();//當前的武器列表
    Dictionary<int, int> m_AmmoInventory = new Dictionary<int, int>();//彈夾/剩餘彈藥數量

    void Awake()
    {
        Instance = this;
    }
    
    void Start()
    {
        Cursor.lockState = CursorLockMode.Locked;//屏幕鎖定
        Cursor.visible = false;//隱藏硬件指針

        m_IsPaused = false;//初始化爲沒有按鍵按下
        m_Grounded = true;//初始化爲在地面上
        
        MainCamera.transform.SetParent(CameraPosition, false);//主相機設置到相機位置子物體下，不使用世界座標
        MainCamera.transform.localPosition = Vector3.zero;//初始化到父物體座標原點
        MainCamera.transform.localRotation = Quaternion.identity;//初始化相機角度爲默認
        m_CharacterController = GetComponent<CharacterController>();//初始化角色控制器爲當前物體的角色控制器

        for (int i = 0; i < startingWeapons.Length; ++i)//遍歷開始的武器
        {
            PickupWeapon(startingWeapons[i]);
        }

        for (int i = 0; i < startingAmmo.Length; ++i)//設置初始的彈藥量
        {
            ChangeAmmo(startingAmmo[i].ammoType, startingAmmo[i].amount);
        }
        
        m_CurrentWeapon = -1;//初始化當前武器爲沒有
        ChangeWeapon(0);//設置當前武器爲0號武器

        for (int i = 0; i < startingAmmo.Length; ++i)//裝載當前的彈藥量
        {
            m_AmmoInventory[startingAmmo[i].ammoType] = startingAmmo[i].amount;
        }

        m_VerticalAngle = 0.0f;//初始垂直角度爲0
        m_HorizontalAngle = transform.localEulerAngles.y;//水平角度爲當前物體歐拉角的y值
    }

    void Update()
    {
        if (CanPause && Input.GetButtonDown("Menu"))//按下菜單鍵，就先顯示菜單
        {
            PauseMenu.Instance.Display();
        }
        
        FullscreenMap.Instance.gameObject.SetActive(Input.GetButton("Map")); //大地圖顯示由Map鍵控制

        bool wasGrounded = m_Grounded;//判斷過去一次刷新中玩家是否在地面上
        bool loosedGrounding = false;//不在地面

        //we define our own grounded and not use the Character controller one as the character controller can flicker
        //between grounded/not grounded on small step and the like. So we actually make the controller "not grounded" only
        //if the character controller reported not being grounded for at least .5 second;
        //我們定義自己的接地，不使用角色控制器，因爲角色控制器會閃爍
        //在接地/不接地小臺階等之間。所以我們實際上只讓控制器“不接地”
        //如果角色控制器報告至少0.5秒沒有接地；

        if (!m_CharacterController.isGrounded)//角色控制器的不在地面
        {
            if (m_Grounded)//當前狀態在地上
            {
                m_GroundedTimer += Time.deltaTime;//計算在空中上的時間
                if (m_GroundedTimer >= 0.5f)
                {
                    loosedGrounding = true;//設置當前狀態是在空中
                    m_Grounded = false;
                }
            }
        }
        else
        {
            m_GroundedTimer = 0.0f;
            m_Grounded = true;
        }


        Speed = 0;
        Vector3 move = Vector3.zero;
        if (!m_IsPaused && !LockControl)//沒有按下按鈕，並且沒有鎖定控制
        {
            // Jump (we do it first as 
            if (m_Grounded && Input.GetButtonDown("Jump"))//在地上並且按下Jump鍵
            {
                m_VerticalSpeed = JumpSpeed;//垂直速度升級爲5
                m_Grounded = false;//沒在地上
                loosedGrounding = true;//在空中
                FootstepPlayer.PlayClip(JumpingAudioCLip, 0.8f,1.1f);//播放音效
            }
            //判斷是否在奔跑中，如果當前武器的狀態等於等待，而且按下了奔跑鍵
            bool running = m_Weapons[m_CurrentWeapon].CurrentState == Weapon.WeaponState.Idle && Input.GetButton("Run");
            float actualSpeed = running ? RunningSpeed : PlayerSpeed;//設置當前的實際速度，

            if (loosedGrounding)//在空中也會到受到是否在奔跑的影響
            {
                m_SpeedAtJump = actualSpeed;
            }

            // Move around with WASD
            move = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxisRaw("Vertical"));//控制移動向量
            if (move.sqrMagnitude > 1.0f)//當前移動向量平方長度大於1，就歸一化，禁止其大於1
                move.Normalize();

            float usedSpeed = m_Grounded ? actualSpeed : m_SpeedAtJump;//當前使用的速度，在地上就使用實際速度，在空中就是用跳躍速度
            
            move = move * usedSpeed * Time.deltaTime;//移動向量
            
            move = transform.TransformDirection(move);//將移動向量轉爲世界座標軸
            m_CharacterController.Move(move);//開始移動
            
            // Turn player
            float turnPlayer =  Input.GetAxis("Mouse X") * MouseSensitivity;//靈敏度控制，並獲取他的鼠標當前X軸翻轉的角度，也就是偏航角
            m_HorizontalAngle = m_HorizontalAngle + turnPlayer;//獲取到當前的角度
            //控制其橫向角度在0到360之間
            if (m_HorizontalAngle > 360) m_HorizontalAngle -= 360.0f;
            if (m_HorizontalAngle < 0) m_HorizontalAngle += 360.0f;
            
            Vector3 currentAngles = transform.localEulerAngles;//獲取到當前的角度
            currentAngles.y = m_HorizontalAngle;//將y軸旋轉度數設置爲當前鼠標的實際旋轉角度
            transform.localEulerAngles = currentAngles;//

            // Camera look up/down
            var turnCam = -Input.GetAxis("Mouse Y");//控制鏡頭上下的
            turnCam = turnCam * MouseSensitivity;
            m_VerticalAngle = Mathf.Clamp(turnCam + m_VerticalAngle, -89.0f, 89.0f);//將值限定在-89到89度之間，防止出現
            currentAngles = CameraPosition.transform.localEulerAngles;
            currentAngles.x = m_VerticalAngle;
            CameraPosition.transform.localEulerAngles = currentAngles;
  
            //判斷當前武器是否開火
            m_Weapons[m_CurrentWeapon].triggerDown = Input.GetMouseButton(0);

            Speed = move.magnitude / (PlayerSpeed * Time.deltaTime);

            if (Input.GetButton("Reload"))//重新加載
                m_Weapons[m_CurrentWeapon].Reload();

            if (Input.GetAxis("Mouse ScrollWheel") < 0)//就是鼠標中鍵滑動控制武器
            {
                ChangeWeapon(m_CurrentWeapon - 1);
            }
            else if (Input.GetAxis("Mouse ScrollWheel") > 0)
            {
                ChangeWeapon(m_CurrentWeapon + 1);
            }
            
            //Key input to change weapon

            for (int i = 0; i < 10; ++i)//數字鍵快速切換當前武器
            {
                if (Input.GetKeyDown(KeyCode.Alpha0 + i))
                {
                    int num = 0;
                    if (i == 0)
                        num = 10;
                    else
                        num = i - 1;

                    if (num < m_Weapons.Count)
                    {
                        ChangeWeapon(num);
                    }
                }
            }
        }

        // Fall down / gravity
        m_VerticalSpeed = m_VerticalSpeed - 10.0f * Time.deltaTime;//計算當前重力
        if (m_VerticalSpeed < -10.0f)//最大重力爲-10
            m_VerticalSpeed = -10.0f; // max fall speed
        var verticalMove = new Vector3(0, m_VerticalSpeed * Time.deltaTime, 0);
        var flag = m_CharacterController.Move(verticalMove);//施加重力

        if ((flag & CollisionFlags.Below) != 0)//到地面了
            m_VerticalSpeed = 0;

        if (!wasGrounded && m_Grounded)//落地時播放音效
        {
            FootstepPlayer.PlayClip(LandingAudioClip, 0.8f,1.1f);
        }
    }

    public void DisplayCursor(bool display)//是否隱藏鼠標
    {
        m_IsPaused = display;
        Cursor.lockState = display ? CursorLockMode.None : CursorLockMode.Locked;
        Cursor.visible = display;
    }

    void PickupWeapon(Weapon prefab)//拾撿武器
    {
        //TODO : maybe find a better way than comparing name...
        if (m_Weapons.Exists(weapon => weapon.name == prefab.name))//以及有了該武器
        {//if we already have that weapon, grant a clip size of the ammo type instead
            ChangeAmmo(prefab.ammoType, prefab.clipSize);//就刷新彈藥量
        }
        else//否則就創建一把新的武器
        {
            var w = Instantiate(prefab, WeaponPosition, false);
            w.name = prefab.name;
            w.transform.localPosition = Vector3.zero;
            w.transform.localRotation = Quaternion.identity;
            w.gameObject.SetActive(false);//不顯示
            
            w.PickedUp(this);//將這個武器的歸屬權給予玩家
            
            m_Weapons.Add(w);//武器列表增加
        }
    }

    void ChangeWeapon(int number)//根據索引值改變武器
    {
        if (m_CurrentWeapon != -1)
        {
            m_Weapons[m_CurrentWeapon].PutAway();//初始化
            m_Weapons[m_CurrentWeapon].gameObject.SetActive(false);//設置爲不可見
        }

        m_CurrentWeapon = number;//設置當前武器
        //控制其不會超出範圍
        if (m_CurrentWeapon < 0)
            m_CurrentWeapon = m_Weapons.Count - 1;
        else if (m_CurrentWeapon >= m_Weapons.Count)
            m_CurrentWeapon = 0;
        //顯示武器
        m_Weapons[m_CurrentWeapon].gameObject.SetActive(true);
        m_Weapons[m_CurrentWeapon].Selected();//設置當前武器已被選擇
    }

    public int GetAmmo(int ammoType)//獲取彈藥量
    {
        int value = 0;
        m_AmmoInventory.TryGetValue(ammoType, out value);//從玩家的彈藥倉庫裏面去獲取該武器的總彈藥量

        return value;
    }

    public void ChangeAmmo(int ammoType, int amount)//改變彈藥數量,通過彈藥類型和數量
    {
        if (!m_AmmoInventory.ContainsKey(ammoType))//判斷是否有這個類型的彈藥
            m_AmmoInventory[ammoType] = 0;

        var previous = m_AmmoInventory[ammoType];
        m_AmmoInventory[ammoType] = Mathf.Clamp(m_AmmoInventory[ammoType] + amount, 0, 999);//限制最小量與最大量

        if (m_Weapons[m_CurrentWeapon].ammoType == ammoType)
        {
            if (previous == 0 && amount > 0)//如果倉庫中沒有彈藥了，卻要切換，就隱藏該武器
            {//we just grabbed ammo for a weapon that add non left, so it's disabled right now. Reselect it.
                m_Weapons[m_CurrentWeapon].Selected();//判斷當前武器的狀態
            }
            
            WeaponInfoUI.Instance.UpdateAmmoAmount(GetAmmo(ammoType));//刷新彈藥量
        }
    }

    public void PlayFootstep()//播放音效
    {
        FootstepPlayer.PlayRandom();
    }
}