/**
 * inspired by Entitas' Systems
 * @see https://github.com/sschmid/Entitas-CSharp/wiki/Systems
 */
export interface ISystem {
    /**
     * in a similar way to Unity's `Start()`, we can do some initialization works:
     * * create global entities
     * * init event listeners
     */
    initialize?(canvas: HTMLCanvasElement): void;
    /**
     * in a similar way to Unity's `Update()`, run once per frame
     */
    execute?(): Promise<void>;
    /**
     * run at the end of each frame
     */
    cleanup?(): void;
    /**
     * run once at the end of your program
     */
    tearDown?(): void;
}