polygonjs-engine/src/engine/viewers/utils/WebglController.ts

node-based webgl 3D engine https://polygonjs.com

import {BaseViewerType} from '../_Base';

export class WebGLController {
	public request_animation_frame_id: number | undefined;

	constructor(protected viewer: BaseViewerType) {}

	init() {
		const canvas = this.viewer.canvas();
		if (canvas) {
			canvas.onwebglcontextlost = this._on_webglcontextlost.bind(this);
			canvas.onwebglcontextrestored = this._on_webglcontextrestored.bind(this);
		}
	}

	protected _on_webglcontextlost() {
		console.warn('context lost at frame', this.viewer.scene().frame());
		// event.preventDefault();
		if (this.request_animation_frame_id) {
			cancelAnimationFrame(this.request_animation_frame_id);
		} else {
			console.warn('request_animation_frame_id not initialized');
		}
		console.warn('not canceled', this.request_animation_frame_id);
	}
	protected _on_webglcontextrestored() {
		console.log('context restored');
	}
}