import { Scene } from "three";
import { PerspectiveCamera } from "../camera/perspective-camera";
import { Identifiable } from "../identifiable";
import { Renderer } from "../renderer";
import { Entity } from "./entity";
/**
 * The Stage represents a collection of objects as a hierarchy to be executed
 * by the Renderer. A Stage can be thought of as a single Level.
 *
 * Only one Stage can be active at any one time.
 */
export declare abstract class Stage extends Identifiable {
    private readonly _objects;
    private readonly _queue;
    private readonly _root;
    private readonly _camera;
    private readonly _threeScene;
    constructor();
    /**
     * Access the top-most root entity for the Stage
     */
    get root(): Entity;
    /**
     * Access the default camera for the Stage
     */
    get camera(): PerspectiveCamera;
    /**
     * Access the three.js Scene backing for the Stage
     */
    get threeScene(): Scene;
    /**
     * Queue a new object instance for creation
     *
     * @param instance The object instance to be created
     */
    queue<T extends Entity>(instance: T): Promise<T>;
    /**
     * Called automatically by the renderer when viewport size is changed
     *
     * @param newWidth - The new width of the renderer
     * @param newHeight - The new height of the renderer
     */
    _resize(newWidth: number, newHeight: number, renderer: Renderer): void;
    _pause(renderer: Renderer): void;
    _destroy(renderer: Renderer): void;
    _resume(renderer: Renderer): void;
    /**
     * Called automatically every frame by the Renderer
     *
     * @param deltaTime The time difference between last and current frame in seconds
     */
    _update(deltaTime: number, renderer: Renderer): void;
}