LittleJS

LittleJS Logo LittleJS - The Tiny JavaScript Game Engine That Can

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๐Ÿš‚ All aboard!

LittleJS is a lightweight open source HTML5 game engine designed for modern web development. Itโ€™s small footprint is packed with a comprehensive feature set, including hybrid rendering, physics, particles, sound effects, music, input handling, and debug tools. The code is very clean and well documented with some fun examples to get you started. Choo-Choo! ๐Ÿš‚

## [Demo](https://killedbyapixel.github.io/LittleJS/examples/starter/) | [Docs](https://killedbyapixel.github.io/LittleJS/docs) | [Trailer](https://youtu.be/chuBzGjv7Ms) | [Discord](https://discord.gg/zb7hcGkyZe) | [Tutorial](https://github.com/KilledByAPixel/LittleJS/blob/main/examples/breakoutTutorial/README.md)

LittleJS Screenshot

About LittleJS

LittleJS is a small but powerful game engine with many features and no depenencies.

โœจ Graphics

๐Ÿ”Š Audio

๐ŸŽฎ Input

๐Ÿ’ฅ Physics

๐Ÿš€ Flexability

๐Ÿ› ๏ธ And moreโ€ฆ

Demos

Starter Project - Clean example with only a few things to get you started

Puzzle Game - Match 3 puzzle game with HD rendering and high score tracking

Platformer - Platformer/shooter with procedural generation and destruction

Breakout - Breakout game with post processing effect

Stress Test - Max sprite/object test and music system demo

Particle System Designer - Particle system editor and visualizer

How to use LittleJS

To use LittleJS download the latest package from GitHub or call npm install littlejsengine. This package contains the engine and several small examples.

You can use the empty example template as a starting point. This file contains just the minimal setup to start the engine. You can also download and include littlejs.js or littlejs.min.js.

If your game loads any files like images you will need to run a local web server. Some editors can do this automatically like Visual Studio Code with the Live Server plugin. You can also use http-server via npm.

The Breakout Tutorial is provided to demonstrate how to make a simple game from scratch. The tutorial is also available on YouTube.

There is also a GitNation talk that explains how LittleJS works and some tips on how to use it.

Builds

To easily include LittleJS in your game, you can use one of the 3 pre-built js files. These are also built automatically by the build scripts.

LittleJS can also be imported as a module. There are two module flavors that are automatically built.

To rebuild the engine you must first run npm install to setup the necessary npm dependencies. Then call npm run build to build the engine.

The starter example project also includes a node js file build.js that compresses everything into a tiny zip file using Google Closure, UglifyJS, and ECT Zip.

Engine Source Code

This engine is made with simplicity in mind using clean easy to read code. There are only a few core files used by the entire engine.

Optional Components, these components are built to synergize with the rest of the engine but are not required.

LittleJS Setup

To start LittleJS, you must create 5 functions and pass them to engineInit. A canvas will automatically be created and added to the document.

function gameInit()
{
    // called once after the engine starts up
    // setup the game
}

function gameUpdate()
{
    // called every frame at 60 frames per second
    // handle input and update the game state
}

function gameUpdatePost()
{
    // called after physics and objects are updated
    // setup camera and prepare for render
}

function gameRender()
{
    // called before objects are rendered
    // draw any background effects that appear behind objects
}

function gameRenderPost()
{
    // called after objects are rendered
    // draw effects or hud that appear above all objects
}

// Startup LittleJS Engine
engineInit(gameInit, gameUpdate, gameUpdatePost, gameRender, gameRenderPost, 'tiles.png');

LittleJS Objects

Though not required, LittleJS is intended to be used as an object oriented system by extending the base class EngineObject with your own. This lightweight class provides many useful features including physics, collision, parent/child system, and sorted rendering. Engine objects are automatically added to the global list of objects where they will be updated and rendered until destroyed.

Here is a template you can use to make objects that behave however you want. See the examples for a complete demonstration.

class MyObject extends EngineObject 
{
    constructor(pos, size, tileIndex, tileSize, angle)
    {
        super(pos, size, tileIndex, tileSize, angle);
    }

    update()
    {
        // update object physics and position
        super.update(); 
    }

    render()
    {
        // draw object as a sprite
        super.render();
    }
}

Debugging

Debug builds of LittleJS have a special menu that can be opened by pressing the Esc key.

Games Made With LittleJS

Here are a few of the amazing games people are making with LittleJS.

LittleJS Logo