WuXia/assets/Scripts/CComEx/VisibleRangeClipping.ts

import { _decorator,Node, Rect, rect, Mat4, mat4, Component, Camera, director, View, view, UITransform, Vec3 } from "cc";


const {ccclass, property, menu, requireComponent, executeInEditMode, playOnFocus} = _decorator;

let _rect_temp_visible: Rect = rect();
let _rect_temp_child: Rect = rect();

let _mat4_temp: Mat4 = mat4();
let _mat4_camera_temp: Mat4 = mat4();

@ccclass
export default class VisibleRangeClipping extends Component {

    @property(Camera)
    camera : Camera = null;

    left:Vec3 = new Vec3();
    right:Vec3 = new Vec3();
    mid:Vec3 = new Vec3();

    private _checkContentNode: Node;

    // LIFE-CYCLE CALLBACKS:

    protected onLoad(): void {
        if(this.camera){
            this._initCheck();
        }
    }

    SetCamera(camera:Camera){
        this.camera = camera;
        this._initCheck();
    }

    private _initCheck() {
        this._checkContentNode = this.node;
    }
    
    private _updateOpacity () {
        let viewNode = this._checkContentNode;
        if (!viewNode) return;
        _rect_temp_visible = this.camera.node.getChildByName("CameraRect").getComponent(UITransform).getBoundingBoxToWorld();
        let children = viewNode.children;
        let isShow = true;
        for (let i = 0, ilen = children?.length; i < ilen; i++) {
            // 参考 getBoundingBox 算法计算包围盒.
            let c = children[i];
            //if (c.name == 'tipCenter' || c['clip']) continue;
            if (c.getComponent(VisibleRangeClipping)) continue;
            _rect_temp_child = c.getComponent(UITransform).getBoundingBoxToWorld();
            isShow = _rect_temp_visible.intersects(_rect_temp_child);
            CNodeUtils.setOpacity(children[i],isShow ? 255 : 0);
        }
    }

    update (dt) {
        if (!(director.getTotalFrames() % 6)) {
            this._updateOpacity();
        }
    }
}