The Scene Manager

The scene manager loads scenes and handles transitions between them. Scenes are registered on the game with addScene (see The Game Class) and defined by extending Scene (see Creating a Scene).

In systems extending GameSystem it is available as this.sceneManager. See Custom Components and Systems.

Loading a scene

loadScene switches to the scene registered under the given name. The transition takes effect on the next frame.

import { GameSystem } from "angry-pixel";

export class GameOverSystem extends GameSystem {
    onUpdate() {
        if (/* game over condition */) {
            this.sceneManager.loadScene("MainMenu");
        }
    }
}

When a scene is loaded, the manager:

1. Destroys the current scene: disables its systems, removes all its entities, and clears all intervals.
2. Loads the new scene’s assets and registers its systems.
3. Once the assets have finished loading, creates the new scene’s entities.

Loading an unregistered name throws an error.

Preserving entities across scenes

loadScene accepts an optional component type as a second argument. Entities that have a component of that type are preserved across the transition instead of being removed. This is useful for entities that should persist between scenes, such as a player or a score holder.

import { Persistent } from "../component/Persistent";

this.sceneManager.loadScene("Level2", Persistent);

Scene loading state

if (this.sceneManager.sceneLoadedThisFrame) {
    // run setup that depends on the new scene's entities
}