《Cocos 游戏开发实战》7.1 输入与角色控制

// assets/scripts/core/input-intent.ts
export interface InputIntent {
  /** 本帧是否有一次新的「按下跳跃」——边沿触发，读一次就清掉。 */
  consumeJump(): boolean;
  /** 跳跃键当前是否被按住——用于可变高度跳跃。 */
  isHolding(): boolean;
}

// assets/scripts/game/input-bridge.ts
import { _decorator, Component, input, Input, EventKeyboard, EventTouch, KeyCode } from 'cc';
const { ccclass } = _decorator;

@ccclass('InputBridge')
export class InputBridge extends Component {
  private jumpQueued = false;
  private holdJump = false;

  onEnable(): void {
    input.on(Input.EventType.KEY_DOWN, this.onKeyDown, this);
    input.on(Input.EventType.KEY_UP, this.onKeyUp, this);
    input.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
    input.on(Input.EventType.TOUCH_END, this.onTouchEnd, this);
  }

  onDisable(): void {
    input.off(Input.EventType.KEY_DOWN, this.onKeyDown, this);
    input.off(Input.EventType.KEY_UP, this.onKeyUp, this);
    input.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
    input.off(Input.EventType.TOUCH_END, this.onTouchEnd, this);
  }

  private onKeyDown(e: EventKeyboard): void {
    if (e.keyCode === KeyCode.SPACE || e.keyCode === KeyCode.ARROW_UP) {
      this.jumpQueued = true;
      this.holdJump = true;
    }
  }

  private onKeyUp(e: EventKeyboard): void {
    if (e.keyCode === KeyCode.SPACE || e.keyCode === KeyCode.ARROW_UP) {
      this.holdJump = false;
    }
  }

  private onTouchStart(_e: EventTouch): void { this.jumpQueued = true; this.holdJump = true; }
  private onTouchEnd(_e: EventTouch): void { this.holdJump = false; }

  consumeJump(): boolean {
    const q = this.jumpQueued;
    this.jumpQueued = false;
    return q;
  }

  isHolding(): boolean { return this.holdJump; }
}

// assets/scripts/game/player-controller.ts
import {
  _decorator, Component, Collider2D, Contact2DType, IPhysics2DContact,
  RigidBody2D, Vec2, ERigidBody2DType,
} from 'cc';
const { ccclass, property } = _decorator;

@ccclass('PlayerController')
export class PlayerController extends Component {
  @property({ range: [400, 1600], slide: true, tooltip: '起跳初速度（像素/秒）' })
  jumpVelocity = 900;

  @property({ range: [0.05, 0.95], slide: true, step: 0.05, tooltip: '松手时的速度保留比例' })
  jumpCut = 0.45;

  @property({ type: RigidBody2D })
  body: RigidBody2D | null = null;

  private grounded = false;

  onLoad(): void {
    const col = this.getComponent(Collider2D);
    if (col) {
      col.on(Contact2DType.BEGIN_CONTACT, this.onBegin, this);
      col.on(Contact2DType.END_CONTACT, this.onEnd, this);
    }
    if (this.body) {
      this.body.type = ERigidBody2DType.Dynamic;
      this.body.fixedRotation = true;
    }
  }

  private onBegin(_self: Collider2D, _other: Collider2D, _contact: IPhysics2DContact | null): void {
    this.grounded = true;
  }

  private onEnd(): void { this.grounded = false; }

  tryJump(): boolean {
    if (!this.grounded || !this.body) return false;
    this.body.linearVelocity = new Vec2(0, this.jumpVelocity);
    this.grounded = false;
    return true;
  }

  cutJump(): void {
    if (!this.body) return;
    const v = this.body.linearVelocity;
    if (v.y > 0) this.body.linearVelocity = new Vec2(v.x, v.y * this.jumpCut);
  }
}

// assets/scripts/core/jump-gate.ts
export interface JumpGateConfig {
  /** 离地后仍允许起跳的宽限时间（秒），俗称土狼时间。 */
  coyoteTime: number;
  /** 落地之前提前按下的缓存时间（秒）。 */
  bufferTime: number;
}

export class JumpGate {
  private airborneFor = 0;
  private bufferedFor = Number.POSITIVE_INFINITY;
  private readonly coyoteTime: number;
  private readonly bufferTime: number;

  constructor(cfg: JumpGateConfig) {
    this.coyoteTime = cfg.coyoteTime;
    this.bufferTime = cfg.bufferTime;
  }

  /** 每帧调用一次；grounded 表示本帧是否踩在地上。 */
  step(dt: number, grounded: boolean): void {
    this.airborneFor = grounded ? 0 : this.airborneFor + dt;
    this.bufferedFor += dt;
  }

  /** 玩家按下跳跃键时调用。 */
  pressJump(): void { this.bufferedFor = 0; }

  /** 本帧是否应该真正起跳；返回 true 表示这次缓冲已被消费。 */
  tryConsume(): boolean {
    const canJump = this.airborneFor <= this.coyoteTime;
    const wants = this.bufferedFor <= this.bufferTime;
    if (!canJump || !wants) return false;
    this.bufferedFor = Number.POSITIVE_INFINITY;
    this.airborneFor = Number.POSITIVE_INFINITY;
    return true;
  }
}

[
  { "__type__": "cc.Prefab", "_name": "Player", "data": { "__id__": 1 } },
  {
    "__type__": "cc.Node",
    "_name": "Player",
    "_parent": null,
    "_children": [],
    "_components": [ { "__id__": 2 }, { "__id__": 3 }, { "__id__": 4 }, { "__id__": 5 } ],
    "_lpos": { "__type__": "cc.Vec3", "x": 0, "y": 0, "z": 0 },
    "_layer": 33554432
  },
  {
    "__type__": "cc.UITransform",
    "node": { "__id__": 1 },
    "_contentSize": { "__type__": "cc.Size", "width": 48, "height": 64 },
    "_anchorPoint": { "__type__": "cc.Vec2", "x": 0.5, "y": 0.5 }
  },
  {
    "__type__": "cc.BoxCollider2D",
    "node": { "__id__": 1 },
    "size": { "__type__": "cc.Size", "width": 40, "height": 60 },
    "offset": { "__type__": "cc.Vec2", "x": 0, "y": 0 },
    "sensor": false,
    "group": 1
  },
  {
    "__type__": "cc.RigidBody2D",
    "node": { "__id__": 1 },
    "_type": 2,
    "fixedRotation": true,
    "gravityScale": 1
  },
  {
    "__type__": "PlayerController",
    "node": { "__id__": 1 },
    "jumpVelocity": 900,
    "jumpCut": 0.45
  }
]