polygonjs-engine/src/engine/scene/utils/LoadingController.ts

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

import {PolyScene} from '../PolyScene';
import {SceneEventType} from './events/SceneEventsController';
import {EventContext} from './events/_BaseEventsController';

export class LoadingController {
	constructor(private scene: PolyScene) {}

	private _LOADED_EVENT_CONTEXT: EventContext<Event> | undefined;
	get LOADED_EVENT_CONTEXT() {
		return (this._LOADED_EVENT_CONTEXT = this._LOADED_EVENT_CONTEXT || {event: new Event(SceneEventType.LOADED)});
	}

	_loading_state: boolean = false;
	_auto_updating: boolean = true;
	_first_object_loaded: boolean = false;

	markAsLoading() {
		this._set_loading_state(true);
	}
	async markAsLoaded() {
		this.scene.missingExpressionReferencesController.resolve_missing_references();
		await this._set_loading_state(false);
		this.trigger_loaded_event();
	}
	trigger_loaded_event() {
		// we only dispatch events in the browser. If this is run from nodejs, we do not.
		if (globalThis.Event) {
			this.scene.eventsDispatcher.sceneEventsController.processEvent(this.LOADED_EVENT_CONTEXT);
		}
	}

	private async _set_loading_state(state: boolean) {
		this._loading_state = state;
		await this.set_auto_update(!this._loading_state);
	}
	isLoading() {
		return this._loading_state;
	}
	loaded() {
		return !this._loading_state;
	}
	autoUpdating() {
		return this._auto_updating;
	}
	async set_auto_update(new_state: boolean) {
		if (this._auto_updating !== new_state) {
			this._auto_updating = new_state;
			if (this._auto_updating) {
				// if this.env_is_development()
				// 	this.performance().start()

				const root = this.scene.root();
				if (root) {
					await root.processQueue();
				}
			}
		}
	}

	on_first_object_loaded() {
		if (!this._first_object_loaded) {
			this._first_object_loaded = true;

			const loader = document.getElementById('scene_loading_container');
			if (loader) {
				loader.parentElement?.removeChild(loader);
			}
		}
	}

	// on_all_objects_loaded() {
	// 	// POLY.viewer_loaders_manager().dipose_loaders()
	// }
}