KnitFlow/assets/core_tgx/base/ResolutionAutoFit.ts

import { _decorator, Component, view, screen, Size, size, ResolutionPolicy } from 'cc';
const { ccclass, property } = _decorator;

const CHECK_INTERVAL = 0.1;

@ccclass('tgxResolutionAutoFit')
export class ResolutionAutoFit extends Component {
    private _oldSize: Size = size();
    start() {
        this.adjustResolutionPolicy();
    }

    private lastCheckTime = 0;
    update(deltaTime: number) {
        this.lastCheckTime += deltaTime;
        if (this.lastCheckTime < CHECK_INTERVAL) {
            return;
        }
        this.lastCheckTime = 0;

        this.adjustResolutionPolicy();
    }

    adjustResolutionPolicy() {
        let winSize = screen.windowSize;
        if (!this._oldSize.equals(winSize)) {
          
            let ratio = winSize.width / winSize.height;
            let drs = view.getDesignResolutionSize();
            let drsRatio = drs.width / drs.height;
            
            if (ratio > drsRatio) {
                //wider than desgin. fixed height
                view.setResolutionPolicy(ResolutionPolicy.FIXED_HEIGHT);
           
            }
            else {
                //
                view.setResolutionPolicy(ResolutionPolicy.FIXED_WIDTH);
                
                
            }
            view.emit('canvas-resize')
          
            this._oldSize.set(winSize);
        }
    }
  
}