Organizing your game code is essential for building scalable, maintainable, and bug-free games. As your Phaser project grows, a well-structured codebase will help you manage complexity, collaborate with others, and add new features efficiently.
This section covers:
- Why code organization matters
- Common code organization patterns in Phaser
- Using modules and classes
- Practical examples
- Exercises with solutions
- Why Code Organization Matters
Key Benefits:
- Readability: Easier to understand and navigate your code.
- Maintainability: Simplifies fixing bugs and adding features.
- Reusability: Encourages code reuse across different parts of your game or future projects.
- Collaboration: Makes it easier for teams to work together.
- Common Code Organization Patterns in Phaser
Phaser projects can be organized in several ways. Here are the most common patterns:
| Pattern | Description | When to Use |
|---|---|---|
| Single File | All code in one file | Very small prototypes |
| Scene-based Structure | Each scene in its own file/class | Most Phaser games |
| Modular Structure | Separate files for scenes, objects, utilities, and configuration | Medium to large projects |
| Component-based | Game objects composed of reusable components (advanced) | Large, complex games |
Tip: For most games, a modular, scene-based structure is recommended.
- Using Modules and Classes
Modern JavaScript (ES6+) supports modules and classes, which are ideal for organizing Phaser code.
3.1. Scene Classes
Each game scene (e.g., MainMenu, Game, GameOver) should be its own class in a separate file.
Example: Creating a Scene Class
// src/scenes/MainMenu.js
import Phaser from 'phaser';
export default class MainMenu extends Phaser.Scene {
constructor() {
super('MainMenu');
}
preload() {
// Load assets
this.load.image('logo', 'assets/logo.png');
}
create() {
// Add logo to the scene
this.add.image(400, 300, 'logo');
// Start the game on click
this.input.once('pointerdown', () => {
this.scene.start('Game');
});
}
}Explanation:
MainMenuextendsPhaser.Scene.- The
preloadmethod loads assets. - The
createmethod sets up the scene and handles input.
3.2. Game Objects as Classes
Custom game objects (e.g., Player, Enemy) can also be classes.
// src/objects/Player.js
import Phaser from 'phaser';
export default class Player extends Phaser.Physics.Arcade.Sprite {
constructor(scene, x, y) {
super(scene, x, y, 'player');
scene.add.existing(this);
scene.physics.add.existing(this);
}
update(cursors) {
if (cursors.left.isDown) {
this.setVelocityX(-160);
} else if (cursors.right.isDown) {
this.setVelocityX(160);
} else {
this.setVelocityX(0);
}
}
}Explanation:
PlayerextendsPhaser.Physics.Arcade.Sprite.- The constructor adds the player to the scene and enables physics.
- The
updatemethod handles movement.
3.3. Importing and Using Modules
In your main game file, import and use your scene and object classes:
// src/index.js
import Phaser from 'phaser';
import MainMenu from './scenes/MainMenu.js';
import Game from './scenes/Game.js';
const config = {
type: Phaser.AUTO,
width: 800,
height: 600,
scene: [MainMenu, Game],
physics: { default: 'arcade' }
};
const game = new Phaser.Game(config);
- Folder Structure Example
A typical Phaser project might look like this:
/src
/scenes
MainMenu.js
Game.js
GameOver.js
/objects
Player.js
Enemy.js
/utils
helpers.js
index.js
/assets
logo.png
player.png
...Explanation:
scenes/: All scene classes.objects/: Custom game object classes.utils/: Utility/helper functions.assets/: Images, sounds, etc.
- Practical Exercise
Exercise
Task:
Refactor the following code so that the player logic is separated into its own class file. Assume you have a Game scene.
Original Code (all in one file):
class Game extends Phaser.Scene {
constructor() {
super('Game');
}
preload() {
this.load.image('player', 'assets/player.png');
}
create() {
this.player = this.physics.add.sprite(400, 300, 'player');
this.cursors = this.input.keyboard.createCursorKeys();
}
update() {
if (this.cursors.left.isDown) {
this.player.setVelocityX(-160);
} else if (this.cursors.right.isDown) {
this.player.setVelocityX(160);
} else {
this.player.setVelocityX(0);
}
}
}Instructions:
- Create a
Player.jsclass in anobjectsfolder. - Move the player logic into this class.
- Update the
Gamescene to use the newPlayerclass.
Solution
Step 1: Create Player.js
// src/objects/Player.js
import Phaser from 'phaser';
export default class Player extends Phaser.Physics.Arcade.Sprite {
constructor(scene, x, y) {
super(scene, x, y, 'player');
scene.add.existing(this);
scene.physics.add.existing(this);
}
move(cursors) {
if (cursors.left.isDown) {
this.setVelocityX(-160);
} else if (cursors.right.isDown) {
this.setVelocityX(160);
} else {
this.setVelocityX(0);
}
}
}Step 2: Update Game.js
// src/scenes/Game.js
import Phaser from 'phaser';
import Player from '../objects/Player.js';
export default class Game extends Phaser.Scene {
constructor() {
super('Game');
}
preload() {
this.load.image('player', 'assets/player.png');
}
create() {
this.player = new Player(this, 400, 300);
this.cursors = this.input.keyboard.createCursorKeys();
}
update() {
this.player.move(this.cursors);
}
}Common Mistakes & Tips:
- Forgetting to add the player to the scene: Always call
scene.add.existing(this)in your custom object’s constructor. - Incorrect import paths: Double-check your import statements and folder structure.
- Not passing the scene to the object constructor: Always pass the scene as the first argument.
- Summary
- Organizing your code into modules and classes makes your Phaser games easier to manage and scale.
- Use a folder structure that separates scenes, objects, and utilities.
- Leverage ES6 modules (
import/export) to keep code clean and maintainable. - Practice refactoring code into separate files and classes for better organization.
Next: In the following section, you'll learn how to manage multiple scenes, allowing for menus, levels, and transitions in your game.
Phaser - Game Development with JavaScript
Module 1: Introduction to Game Development and Phaser
- What is Game Development?
- Overview of Phaser
- Setting Up Your Development Environment
- Your First Phaser Project
Module 2: Phaser Basics
- Understanding the Game Loop
- Game Configuration and Scenes
- Loading and Displaying Images
- Working with Text
- Handling Input (Keyboard and Mouse)
Module 3: Sprites and Animation
Module 4: Game Physics and Interactivity
- Introduction to Physics in Phaser
- Enabling Physics on Sprites
- Collisions and Overlaps
- Interactive Objects and Events
