Scene

Summary

The Scene base class defines the general structure and behavior that all game scenes must follow.
It allows loading resources (assets), registering systems (systems), and configuring entities when loading a scene.
The SceneManager is responsible for instantiating and managing scenes during the game's lifecycle.

Responsibilities

• Define which resources should be loaded (loadAssets()).
• Declare the systems to be used in the scene (registerSystems()).
• Create and configure entities when the scene is ready (createEntities()).

Example of a custom scene

class MainScene extends Scene {
    loadAssets() {
        this.assetManager.loadImage("player.png");
        this.assetManager.loadAudio("background-music.ogg");
    }

    registerSystems() {
        this.addSystems([PlayerControllerSystem, ScoreSystem, EnemyAISystem, PauseMenuSystem]);
    }

    createEntities() {
        const player = this.entityManager.createEntity([
            new Transform({ position: new Vector2(100, 100) }),
            new Player({ health: 100 }),
            new SpriteRenderer({ image: "player.png" }),
        ]);
    }
}

Example of registering and loading scenes

// Registering scenes at game start
game.addScene(MainScene, "MainScene", true); // initial scene
game.addScene(GameOverScene, "GameOverScene");

Example of changing the scene

// Switch to the GameOverScene
sceneManager.loadScene("GameOverScene");

Available methods in Scene

• loadAssets() — Override to load resources.
• registerSystems() — Override to declare systems.
• createEntities() — Override to create entities when the scene is ready.

Important notes

• All scenes share the same instances of EntityManager and AssetManager.
• Systems declared in registerSystems() will be automatically enabled when the scene is loaded.
• Entities created during createEntities() will be available once all assets have been loaded.