CES.js

CES.js is a lightweight Component-Entity-System framework for JavaScript games.

Basic Usage

To define a new component, simply extend CES.Component. Note that each component should have a unique name property.

var Position = CES.Component.extend({
    name: 'position',
    init: function (x, y) {
        this.x = x;
        this.y = y;
    }
});

var Velocity = CES.Component.extend({
    name: 'velocity',
    init: function (x, y) {
        this.x = x;
        this.y = y;
    }
});

var Health = CES.Component.extend({
    name: 'health',
    init: function (maxHealth) {
        this.health = this.maxHealth = maxHealth;
    },
    isDead: function () {
        return this.health <= 0;
    },
    receiveDamage: function (damage) {
        this.health -= damage;
    }
});

An entity is essentially a container of one or more components.

var hero = new CES.Entity();
hero.addComponent(new Position(0, 0));
hero.addComponent(new Velocity(0, 0));
hero.addComponent(new Health(100));

The system is responsible for updating the entities. In a real game there may be a lot of systems, like CollisionSystem, RenderSystem, ControlSystem etc.

var PhysicSystem = CES.System.extend({
    update: function (dt) {
        var entities, position, velocity;

        entities = this.world.getEntities('position', 'velocity');

        entities.forEach(function (entity) {
            position = entity.getComponent('position');
            velocity = entity.getComponent('velocity');
            position.x += velocity.x * dt;
            position.y += velocity.y * dt;
        });
    }
});

The world is the container of all the entities and systems. Calling the update method will sequentially update all the systems, in the order they were added.

var world = new CES.World();

world.addEntity(hero);
// ... add other entities

world.addSystem(new PhysicSystem());
// ... add other systems

requestAnimationFrame(function () {
    world.update(/* interval */);
})

Installation (Browser)

Download the minified js file and include it in your web page.

<script type="text/javascript" src="./ces-browser.min.js"></script>

Installation (Node.js)

If you want to use it in Node.js, you may install it via npm.

npm install ces

Then, in your program:

var CES = require('ces');

Development

Layout:

.
|-- dist         # browser distribution
|-- src          # source code
`-- test         # test scripts

You will need to install node.js and use npm to install the dependencies:

npm install -d

To build the browser distribution (It will use node-browserify to generate a browser distribution, and use UglifyJS to compress):

make

To run the tests with mocha and should.js

make test

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.