import { _decorator, Component, Node,clamp, EventTouch, Vec2, Rect, misc } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('BackgroundDrag')
export class BackgroundDrag extends Component {
    private startTouchPos: Vec2 = new Vec2(0, 0);  // 记录初始触摸位置
    private startNodePos: Vec2 = new Vec2(0, 0);   // 记录初始节点位置

    @property(Node)
    public backgroundNode: Node = null; // 拖动的背景节点

    // 限制背景移动的范围
    @property(Rect)
    public movementBounds: Rect = new Rect(0, 0, 1000, 1000);

    onLoad() {
        this.backgroundNode.on(Node.EventType.TOUCH_START, this.onTouchStart, this);
        this.backgroundNode.on(Node.EventType.TOUCH_MOVE, this.onTouchMove, this);
    }

    onTouchStart(event: EventTouch) {
        this.startTouchPos = event.getLocation();  // 获取触摸起始点
        this.startNodePos = new Vec2(this.backgroundNode.position.x, this.backgroundNode.position.y);  // 记录背景节点的起始位置
    }

    onTouchMove(event: EventTouch) {
        const touchPos = event.getLocation();
        const delta = touchPos.subtract(this.startTouchPos);

        let newPos = this.startNodePos.add(delta);

        // 限制新位置在给定的范围内
        newPos.x = clamp(newPos.x, this.movementBounds.xMin, this.movementBounds.xMax);
        newPos.y = clamp(newPos.y, this.movementBounds.yMin, this.movementBounds.yMax);

        this.backgroundNode.setPosition(newPos.x, newPos.y, this.backgroundNode.position.z);
    }
}