Alex教程每一P的教程原代码加上我自己的理解初步理解写的注释，可供学习Alex教程的人参考
【Unity教程】从0编程制作类银河恶魔城游戏_哔哩哔哩_bilibili
Player.cs
using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;
public class Player : MonoBehaviour
{
[Header("Move Info")]
public float moveSpeed;//定义速度，与xInput相乘控制速度的大小
public float jumpForce;
[Header("Dash Info")]
[SerializeField] private float dashCooldown;
private float dashUsageTimer;//为dash设置冷却时间，在一定时间内不能连续使用
public float dashSpeed;//冲刺速度
public float dashDuration;//持续时间
public float dashDir { get; private set; }
[Header("Collision Info")]
[SerializeField] private Transform groundCheck;//transform类，代表的时物体的位置,后面会来定位子组件的位置
[SerializeField] private float groundCheckDistance;
[SerializeField] private Transform wallCheck;//transform类，代表的时物体的位置,后面会来定位子组件的位置
[SerializeField] private float wallCheckDistance;
[SerializeField] private LayerMask whatIsGround;//LayerMask类，与Raycast配合，https://docs.unity3d.com/cn/current/ScriptReference/Physics.Raycast.html
public int facingDir { get; private set; } = 1;
private bool facingRight = true;//判断是否朝右
#region 定义Unity组件
public Animator anim { get; private set; }//这样才能配合着拿到自己身上的animator的控制权
public Rigidbody2D rb { get; private set; }//配合拿到身上的Rigidbody2D组件控制权
#endregion
#region 定义States
public PlayerStateMachine stateMachine { get; private set; }
public PlayerIdleState idleState { get; private set; }
public PlayerMoveState moveState { get; private set; }
public PlayerJumpState jumpState { get; private set; }
public PlayerAirState airState { get; private set; }
public PlayerDashState dashState { get; private set; }
public PlayerWallSlideState wallSlide { get; private set; }
#endregion
private void Awake()
{
stateMachine = new PlayerStateMachine();
//通过构造函数，在构造时传递信息
idleState = new PlayerIdleState(this, stateMachine, "Idle");
moveState = new PlayerMoveState(this, stateMachine, "Move");
jumpState = new PlayerJumpState(this, stateMachine, "Jump");
airState = new PlayerAirState(this, stateMachine, "Jump");
dashState = new PlayerDashState(this, stateMachine, "Dash");
wallSlide = new PlayerWallSlideState(this, stateMachine, "WallSlide");
//this 就是 Player这个类本身
}//Awake初始化所以State，为所有State传入各自独有的参数，及animBool，以判断是否调用此动画（与animatoin配合完成）
private void Start()
{
anim = GetComponentInChildren<Animator>();//拿到自己身上的animator的控制权
rb = GetComponent<Rigidbody2D>();
stateMachine.Initialize(idleState);
}
private void Update()//在mano中update会自动刷新但其他没有mano的不会故，需要在这个updata中调用其他脚本中的函数stateMachine.currentState.update以实现 //stateMachine中的update
{
stateMachine.currentState.Update();//反复调用CurrentState的Update函数
CheckForDashInput();
}
public void CheckForDashInput()
{
dashUsageTimer -= Time.deltaTime;//给dash上冷却时间
if (Input.GetKeyDown(KeyCode.LeftShift) && dashUsageTimer < 0)
{
dashUsageTimer = dashCooldown;
dashDir = Input.GetAxisRaw("Horizontal");//设置一个值，可以将dash的方向改为你想要的方向而不是你的朝向
if (dashDir == 0)
{
dashDir = facingDir;//只有当玩家没有控制方向时才使用默认朝向
}
stateMachine.ChangeState(dashState);
}
}//将Dash切换设置成一个函数，使其在所以情况下都能使用
public void SetVelocity(float _xVelocity, float _yVelocity)
{
rb.velocity = new Vector2(_xVelocity, _yVelocity);//将rb的velocity属性设置为对应的想要的二维向量。因为2D游戏的速度就是二维向量
FlipController(_xVelocity);//在其他设置速度的时候调用翻转控制器
}//控制速度的函数，此函数在其他State中可能会使用，但仅能通过player.SeVelocity调用
public bool IsGroundDetected()
{
return Physics2D.Raycast(groundCheck.position, Vector2.down, groundCheckDistance, whatIsGround);
}//通过RayCast检测是否挨着地面,https://docs.unity3d.com/cn/current/ScriptReference/Physics.Raycast.html
//xxxxxxxx() => xxxxxxxx == xxxxxxxxxx() return xxxxxxxxx;
public bool IsWallDetected()
{
return Physics2D.Raycast(wallCheck.position, Vector2.right*facingDir, wallCheckDistance, whatIsGround);
}//通过RayCast检测是否挨着地面,https://docs.unity3d.com/cn/current/ScriptReference/Physics.Raycast.html
//xxxxxxxx() => xxxxxxxx == xxxxxxxxxx() return xxxxxxxxx;
private void OnDrawGizmos()
{
Gizmos.DrawLine(groundCheck.position, new Vector3(groundCheck.position.x, groundCheck.position.y - groundCheckDistance));//绘制一条从 from(前面的) 开始到 to（后面的） 的线。
Gizmos.DrawLine(wallCheck.position, new Vector3(wallCheck.position.x + wallCheckDistance, wallCheck.position.y));//绘制一条从 from(前面的) 开始到 to（后面的） 的线。
}//画线函数
public void Flip()
{
facingDir = facingDir * -1;
facingRight = !facingRight;
transform.Rotate(0, 180, 0);//旋转函数,transform不需要额外定义，因为他是自带的
}//翻转函数
public void FlipController(float _x)//目前设置x，目的时能在空中时也能转身
{
if (_x > 0 && !facingRight)//当速度大于0且没有朝右时，翻转
{
Flip();
}
else if (_x < 0 && facingRight)
{
Flip();
}
}
}
PlayerState.cs
using System.Collections;
using System.Collections.Generic;
using System.Security.Authentication.ExtendedProtection;
using UnityEngine;
//被继承的总类，后面的所以state都需要继承它
//实际上Player并没有进入过这个状态，没有调用此脚本，所有的调用均属于此脚本的子脚本
public class PlayerState
{
protected PlayerStateMachine stateMachine;//创建PlayerStateMachine类，以承接来自Player.cs传过来的东西
protected Player player;//创建Player类，以承接来自Player.cs传过来的东西
protected float stateTimer;
#region Unity组件
protected Rigidbody2D rb;//纯简化，将player.rb --> rb
#endregion
private string animBoolName;//控制此时的anim的BOOL值
protected float xInput;//设置一个可以保存当前是否在按移动键的变量
protected float yInput;
public PlayerState(Player _player,PlayerStateMachine _stateMachine,string _animBoolName)
{
this.player = _player;
this.stateMachine = _stateMachine;
this.animBoolName = _animBoolName;
}//构造函数，用于传递信息
public virtual void Enter()
{
player.anim.SetBool(animBoolName, true);//通过animator自带的函数，将animator里的Bool值改变为想要的值
rb = player.rb;//纯简化，将player.rb --> rb
}
public virtual void Update()
{
stateTimer -= Time.deltaTime;//https://docs.unity3d.com/cn/current/ScriptReference/Time-deltaTime.html
//从上一帧到当前帧的间隔（以秒为单位）（只读）。这个表达式就是表示每一帧都不断的减少时间
player.anim.SetFloat("yVelocity", rb.velocity.y);//通过animator自带的函数，将animator里的Float值改变为想要的值,改变yVelocity以控制Jump与Fall动画的切换
xInput = Input.GetAxisRaw("Horizontal");//对于键盘和游戏杆输入，该值将处于 -1...1 的范围内。 由于未对输入进行平滑处理，键盘输入将始终为 -1、0 或 1。 如果您想自己完成键盘输入的所有平滑处理，这非常有用。
yInput = Input.GetAxisRaw("Vertical");
}
public virtual void Exit()
{
player.anim.SetBool(animBoolName, false);//通过animator自带的函数，将animator里的Bool值改变为想要的值
}
}
PlayerStateMachine.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerStateMachine
{
public PlayerState currentState { get; private set; }
public void Initialize(PlayerState _startState)
{
currentState = _startState;
currentState.Enter();
}//初始化状态函数，及通过将idleState传送进来，以便于调用idleState中的Enter函数
public void ChangeState(PlayerState _newState)
{
currentState.Exit();
currentState = _newState;
currentState.Enter();
}//更改状态函数
//1.调用当前状态的Exit函数，使动画为false
//2.传入新的状态，替换原来的状态
//3.调用新的状态的Enter函数
}
PlayerGroundState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
//GroundState用于保证只有在Idle和Move这两个地面状态下才能调用某些函数，并且稍微减少一点代码量
public class PlayerGroundState : PlayerState
{
public PlayerGroundState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}
public override void Enter()
{
base.Enter();
}
public override void Exit()
{
base.Exit();
}
public override void Update()
{
base.Update();
if(player.IsGroundDetected()==false)
{
stateMachine.ChangeState(player.airState);
}// 写这个是为了防止在空中直接切换为moveState了。
if (Input.GetKeyDown(KeyCode.Space) && player.IsGroundDetected())
{
stateMachine.ChangeState(player.jumpState);
}//空格切换为跳跃状态
}
}
PlayerIdleState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerIdleState : PlayerGroundState//继承函数，获得PlayerState里的所有函数和参数
{
public PlayerIdleState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}//构造函数，用于传递信息。
//当外补New出对象时，New出的对象里传入参数
public override void Enter()
{
base.Enter();
}
public override void Exit()
{
base.Exit();
}
public override void Update()
{
base.Update();
if(xInput != 0)
{
stateMachine.ChangeState(player.moveState);//在这里我们能使用Player里的东西，主要是因为我们通过构造函数传过来Player实体，如果不传，则无法使用已经存在了的Player实体。
}
}
}
PlayerMoveState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerMoveState : PlayerGroundState
{
public PlayerMoveState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}//构造函数，用于传递信息。
//当外补New出对象时，New出的对象里传入参数
public override void Enter()
{
base.Enter();
}
public override void Exit()
{
base.Exit();
}
public override void Update()
{
base.Update();
player.SetVelocity(xInput*player.moveSpeed, rb.velocity.y);//player.rb.velocity.y默认的为0,player.moveSpeed在player中定义，但可以在Unity引擎中更改
if (xInput==0)
{
stateMachine.ChangeState(player.idleState);//在这里我们能使用Player里的东西，主要是因为我们通过构造函数传过来Player实体，如果不传，则无法使用已经存在了的Player实体。
}
}
}
PlayerJumpState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerJumpState : PlayerState
{
public PlayerJumpState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}
public override void Enter()
{
base.Enter();
rb.velocity = new Vector2(rb.velocity.x, player.jumpForce);//将y轴速度改变
}
public override void Update()
{
base.Update();
if (rb.velocity.y < 0)//当速度小于0时切换为airState
{
stateMachine.ChangeState(player.airState);//与其说是airState，不如说是FallState
}
}
public override void Exit()
{
base.Exit();
}
}
PlayerAirState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerAirState : PlayerState
{
public PlayerAirState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}
public override void Enter()
{
base.Enter();
}
public override void Exit()
{
base.Exit();
}
public override void Update()
{
base.Update();
if (player.IsGroundDetected())//触地时切换为默认状态
{
stateMachine.ChangeState(player.idleState);
}
if(xInput != 0)//使角色能在空中时改变速度
{
player.SetVelocity(player.moveSpeed* 0.8f * xInput, rb.velocity.y);
}
if(player.IsWallDetected())//在空中碰墙时切换为滑墙状态
{
stateMachine.ChangeState(player.wallSlide);
}
}
}
PlayerDashState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerDashState : PlayerState
{ //由Ground进入
public PlayerDashState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}
public override void Enter()
{
base.Enter();
stateTimer = player.dashDuration;设置Dash可以保持的值
}
public override void Exit()
{
base.Exit();
player.SetVelocity(0, rb.velocity.y);//当退出时使速度为0防止动作结束后速度不变导致的持续移动
}
public override void Update()
{
base.Update();
player.SetVelocity(player.dashSpeed * player.dashDir, 0);//这个写在Update里，防止在x轴方向减速了，同时Y轴写成0，以防止dash还没有完成就从空中掉下去了
if (stateTimer < 0)当timer小于0，切换
{
stateMachine.ChangeState(player.idleState);
}
}
}
PlayerWallSlideState.cs
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerWallSlideState : PlayerState
{
//在空中碰墙时切换为滑墙状态
public PlayerWallSlideState(Player _player, PlayerStateMachine _stateMachine, string _animBoolName) : base(_player, _stateMachine, _animBoolName)
{
}
public override void Enter()
{
base.Enter();
}
public override void Exit()
{
base.Exit();
}
public override void Update()
{
base.Update();
if(xInput!= 0&&player.facingDir!=xInput)//这样做是为了保证在没有接触地面的时候也可以切换回idleState，使控制更加灵活
{
stateMachine.ChangeState(player.idleState);
}
if(player.IsGroundDetected())//接触地面切回idleState
{
stateMachine.ChangeState(player.idleState);
}
if (yInput < 0)
rb.velocity = new Vector2(0,rb.velocity.y);//玩家可以控制是否加速滑墙
else
rb.velocity = new Vector2(0, rb.velocity.y * .7f);//玩家没控制时在墙上滑行时速度减慢一点
}
}
