ArtemisJs

A javascript port of Artemis Entity System Framework. It retains most of the Java version's API and should be able to run on both the client side (script tag or AMD) and server side (CommonJs).

##Differences with the original Java version

• delayedEntityProcessingSystem: will keep running until there's no more entity to process (all entities have timed out)
• bag: remove(int) -> removeByIndex remove(E) -> removeElement
• component/manager/system types are differentiated using a type property (componentType, managerType and systemType respectively) which need to be set using Object.defineProperty.

##How to use

###Setup

####Web

Simply use a script tag. This will add a variable artemis to the global space.

<script src="Artemis.js"></script>

or

<script src="Artemis.min.js"></script>

####AMD

RequireJs example:

require(["Artemis"], function(artemis) {
  // do something here
});

####CommonJs

TODO

###Create a world

var world = artemis.world.create();

world.setSystem(movementSystemInstance);

world.initialize();

###Define a component Use the ExtendHelper to extend the default component or an another component. Component types are differentiated using componentType property (configurable but not enumerable/writable).

var positionComponent = artemis.ExtendHelper.extendComponent(artemis.component, "positionComponent", {
  create: function (x, y) {
    var self = Object.create(this);
    self.x = x;
    self.y = y;
    return self;
  }
});

If you don't want to use ExtendHelper, you will need to use Object.defineProperty to change componentType.

###Create an entity An entity has to be created from the world instance.

var entity = world.createEntity();
entity.addComponent(positionComponent.create());
entity.addToWorld();

###Define an entity system

Similiarly to component, system types are differentiated using systemType property.

var movementSystem = artemis.ExtendHelper.extendSystem(artemis.entityProcessingSystem, "movementSystem", {
  __componentTypes: ["positionComponent", "velocityComponent"],
  create: function () {
    var aspect = artemis.Aspect.getAspectForAll.apply(null, this.__componentTypes);
    var self = artemis.entityProcessingSystem.create.call(this, aspect);
    return self;
  },
  processEntity: function (e) {
    var position = this.positionComponentMapper.get(e);
    var velocity = this.velocityComponentMapper.get(e);

    position.x += velocity.vectorX * this.getWorld().getDelta();
    position.y += velocity.vectorY * this.getWorld().getDelta();
  }
});

and to create a system:

var movementSystemInstance = movementSystem.create();

Component Mappers are injected into the system via __componentTypes property. This could be a string or an array of component type (which should be set when defining a component). You can access these mappers with the convention: componentType + Mapper

##Running the example

The example is the spaceship warrior example port. It is written using Cocos2d-html5 for rendering.

To run it, you will need the Cocos2d-html5 version. You can download the newest version here. The newest version at the moment is v2.2.1.

Then simply copy the example folder into the Cocos2d-html5 folder and run index.html file. It should run with no problem on Firefox, you might need a server to run on other browser.

##Documentation

Visit the wiki.