监听触摸事件

触摸事件可以通过监听 Input.EventType.TOUCH_START 来接收屏幕或者鼠标的事件。

监听方式有两种:

  • 通过 input.on 的方式监听,这种方式会监听屏幕上所有的触摸
  • 通过 node.on 的方式监听时,可以监听某个范围内的触摸事件

考虑到我们需要操作角色跳一步或者两步,因此我们选择将屏幕的左边的触摸用于处理跳一步的输入,而右边用于跳两步。

在 UI 层级里,也就是 UICanvas 节点下方创建两个空的节点,并分别命名为 LeftTouch 和 RightTouch:

create-touch.png

参考下图设定好他们的位置和大小:

left-touch.png

right-touch.png

回到 PlayerController 在里面添加下列属性可以在角色上配置触摸区域:

@property(Node)
leftTouch: Node = null;

@property(Node)
rightTouch: Node = null;

并将刚才创建好的节点拖拽到上面去:

config-touch-nodes.png

PlayerController 里面添加下面的代码:

  • 监听触摸输入:

      setInputActive(active: boolean) {
          if (active) {    
              this.leftTouch.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
              this.rightTouch.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
          } else {        
              this.leftTouch.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
              this.rightTouch.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
          }
      }
    
  • 添加响应触摸的回调:

      onTouchStart(event: EventTouch) {
          const target = event.target as Node;    
          if (target?.name == 'LeftTouch') {
              this.jumpByStep(1);
          } else {
              this.jumpByStep(2);
          }
      }
    

    target 在定义中是 any 类型,因此我们需要通过 as 关键字将其转化为 Node 类型。

    通过 as 关键字可以进行类型转换,当前前提是您得知道他是什么类型。

    取到触摸的目标后,我们就可以通过 name 这个属性来区分用户点击的是右侧的触摸区域还是左侧。

之后运行游戏就可以观察到触摸时的跳跃情况,此时可以通过手机应用扫描下图中的 QR 码来在移动设备上游玩(注意要在一个局域网内)。

完整的 Playercontroller 代码参考如下:

import { _decorator, Component, Vec3, EventMouse, input, Input, Animation, EventTouch, Node } from "cc";
const { ccclass, property } = _decorator;

export const BLOCK_SIZE = 40;

@ccclass("PlayerController")
export class PlayerController extends Component {

    @property(Animation)
    BodyAnim: Animation = null;

    private _startJump: boolean = false;
    private _jumpStep: number = 0;
    private _curJumpTime: number = 0;
    private _jumpTime: number = 0.3;
    private _curJumpSpeed: number = 0;
    private _curPos: Vec3 = new Vec3();
    private _deltaPos: Vec3 = new Vec3(0, 0, 0);
    private _targetPos: Vec3 = new Vec3();
    private _curMoveIndex = 0;

    @property(Node)
    leftTouch: Node = null;

    @property(Node)
    rightTouch: Node = null;

    start() {
        //input.on(Input.EventType.MOUSE_UP, this.onMouseUp, this);
    }

    setInputActive(active: boolean) {
        if (active) {
            //input.on(Input.EventType.MOUSE_UP, this.onMouseUp, this);
            this.leftTouch.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
            this.rightTouch.on(Input.EventType.TOUCH_START, this.onTouchStart, this);
        } else {
            //input.off(Input.EventType.MOUSE_UP, this.onMouseUp, this);
            this.leftTouch.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
            this.rightTouch.off(Input.EventType.TOUCH_START, this.onTouchStart, this);
        }
    }

    reset() {
        this._curMoveIndex = 0;
    }

    onTouchStart(event: EventTouch) {
        const target = event.target as Node;        
        if (target?.name == 'LeftTouch') {
            this.jumpByStep(1);
        } else {
            this.jumpByStep(2);
        }
    }

    onMouseUp(event: EventMouse) {
        if (event.getButton() === 0) {
            this.jumpByStep(1);
        } else if (event.getButton() === 2) {
            this.jumpByStep(2);
        }

    }

    jumpByStep(step: number) {
        if (this._startJump) {
            return;
        }
        this._startJump = true;
        this._jumpStep = step;
        this._curJumpTime = 0;

        const clipName = step == 1 ? 'oneStep' : 'twoStep';
        const state = this.BodyAnim.getState(clipName);
        this._jumpTime = state.duration;

        this._curJumpSpeed = this._jumpStep * BLOCK_SIZE / this._jumpTime;
        this.node.getPosition(this._curPos);
        Vec3.add(this._targetPos, this._curPos, new Vec3(this._jumpStep * BLOCK_SIZE, 0, 0));

        if (this.BodyAnim) {
            if (step === 1) {
                this.BodyAnim.play('oneStep');
            } else if (step === 2) {
                this.BodyAnim.play('twoStep');
            }
        }

        this._curMoveIndex += step;
    }


    onOnceJumpEnd() {
        this.node.emit('JumpEnd', this._curMoveIndex);
    }

    update(deltaTime: number) {
        if (this._startJump) {
            this._curJumpTime += deltaTime;
            if (this._curJumpTime > this._jumpTime) {
                // end
                this.node.setPosition(this._targetPos);
                this._startJump = false;
                this.onOnceJumpEnd();
            } else {
                // tween
                this.node.getPosition(this._curPos);
                this._deltaPos.x = this._curJumpSpeed * deltaTime;
                Vec3.add(this._curPos, this._curPos, this._deltaPos);
                this.node.setPosition(this._curPos);
            }
        }
    }
}

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