OSIS: A Haxe repository from Dvergar

API here : http://dvergar.github.io/osis/ (latest, 0.8.0)
Available on haxelib.

Entity Component System architecture with networking support (for haxe).

Simple API
Simple source
Networking is optional, none of the network API is polluating the ECS
API support for shared code betwen client & server
Automatic & fine-grained serialization of components via PODStream
Avoids magic !

(Iteration from old ECS-Networking-Haxe)

Check out the sample for a quick overview of the architecture. The library assumes you are in a client/server architecture where the server is authoritative.

ECS ?

Entity is an aggregation of data-only components
Logics are in systems
Systems act on components

Networking

Components updates are always done from server to clients (not the other way) and only at your demand.
Messages are the only types of network events that can go both ways.
In a game w/ this framework, communications should sum up to the client sending a list of pressed keys and/or events and the server dispatching everything else.

Notes

Based on my network library Anette TCP (no websockets)
64 components max, 64 entity sets max
Will soon make it network-library agnostic via an API as i want to have websockets w/ hxWebSockets soon. And udprotean for UDP later.

Usage

Setup

var em:EntityManager = new EntityManager();

If you're going networked you can get the network entity manager via.

var net = em.listen("127.0.0.1", 32000);

on the server and

var net = em.connect("127.0.0.1", 32000);

on the client.

EntitySet

An entity set will allow to manipulate entities having the specified components; here CPosition and CMonster.

var entitySet = em.getEntitySet([CPosition, CMonster]);

You will then be able to iterate through entitySet.adds, entitySet.changes, entitySet.removes and entitySet.entities. entitySet.applyChanges() will update the entity set to the last changes.

System

A system is a really simple structure that will give you a loop where you can iterate over your entity sets and an init where you will initialize your entity sets.

Example :

class MovementSystem extends System
{
    var entitySet:EntitySet;

    public override function init()
        entitySet = em.getEntitySet([CPosition, CMonster]);

    public override function loop()
    {
        entitySet.applyChanges();

        for(entity in entitySet.entities)
        {
            var pos = entity.get(CPosition);
            pos.x += 0.1;
            net.markChanged(entity, pos, entitySet);
        }
    }
}

net.markChanged here will notify the change to all the clients.

Network event

The content of an event is called a Message and will be shared among client & server, here is an example :

class MessageHello implements Message
{
    @String public var txt:String;

    public function new() {}
}

The receiver registers to the event

net.addEvent(MessageHello, function(msg:MessageHello, connection:Connection) {
    trace(msg.txt);
});

And the sender sends the message

var msg = new MessageHello();
msg.txt = "coucou";
net.sendEvent(msg);

Templates

A template is a set of components defining a specific entity

public function player()
{
  var entity = em.createEntity();
  var pos = em.addComponent(entity, new CPosition());

  return entity;
}

Adds a template like this em.addTemplate("player", player); and call the template like that em.createEntity("player");

Plugging everything together

class Server
{
    var em:EntityManager = new EntityManager();
    var net:NetEntityManager;

    public function new()
    {
        net = em.listen("127.0.0.1", 32000);
        net.onConnection = onConnection;
        net.onDisconnection = onDisconnection;
        net.addEvent(MessageHello, onMessage);

        em.addSystem(new MovementSystem());

        while(true)
        {
            em.fixedUpdate(function()
            {
                em.processAllSystems();
            });
        }
    }

    function onMessage(msg:MessageHello, connection:Connection)
    {
        trace("Message: " + msg.txt);
    }
    
    function onConnection(connection:Connection)
    {
        var player = net.createEntity("player");
        net.bindEntity(connection, player);
        net.sendWorldStateTo(connection);

        var msg = new MessageHello();
        msg.txt = "youhou";
        net.sendEvent(msg);

        net.addComponent(player, new CHealer());
    }

    function onDisconnection(conn:Connection)
    {
        var boundEntity = net.getBoundEntity(conn);
        net.destroyEntity(boundEntity);
    }

    static function main() {new Server();}
}

Dvergar/OSIS