PeerConnection

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PeerConnection is a lightweight GameConnection for use between two instances of Torque. It saves bandwidth by not sending any periodic information such as moves. There is no mission downloading associated with this type of connection, so it is possible to have as many active PeerConnections as you want, without any overlap problems. They still support password-based connection limits, to protect against backdoor hacking.

It implements all the usual connection callbacks you're used to from GameConnection: OnConnectionAccepted, OnConnectRequest, OnConnect, etc., making it easy to work with. Once a PeerConnection is established, you can treat it like any other object.

PeerConnections can be used to send your own custom NetEvents over the wire with postNetEvent() at the engine level, but most people will probably find it most useful for Torque's standard Remote Procedure Call (RPC) system, i.e. commandToClient/Server. PeerConnection implements commandToPeer mainly to reduce calling confusion. The syntax of commandToPeer() is identical to commandToClient()- the first argument must be a valid PeerConnection:

commandToPeer(%MyPeerConnection, 'SomeServerCommand', "1 is the lonliest number");

Like commandToClient, it supports up to 254 extra optional arguments. On the remote side, PeerConnections use standard "serverCmd" functions, instead of custom "peerCmd" functions, in order to avoid extra bandwidth or processing costs. These functions may be called via a commandToServer call or a commandToPeer call.

The .rar file includes three files for using PeerConnections. peerConnection.cc and peerConnection.h should be placed in your engine/game folder- make sure to add them both to your project and recompile the engine! peerConnection.cs is a template script file, and contains all the standard functions implemented by PeerConnection. You should put this in your example/server/scripts folder, and/or anywhere you plan to use PeerConnections. PeerConnections still use a client-server meme during the connection phase, although I have renamed these (in the interests of Peer-ness) as the Initiator and the Acceptor, which are basically synonymous with Client and Server. Any Torque instance that you intend to have accept PeerConnections must implement the Acceptor callbacks, including PeerConnection::onConnectRequest, PeerConnection::onConnect, and PeerConnection::onDrop. The initiator must implement everything else in peerConnection.cs, including but not limited to PeerConnection::onConnectionAccepted and PeerConnection::onConnectRequestRejected.

PeerConnection adds very little on top of NetConnection other than being able to use it- it is intended to be the bare minimum you can get away with using. I use it extensively in my MMO project to communicate between the various different kinds of servers along with a database server as the true backend. Here is an example of setting up and connecting with a PeerConnection. Notice that the syntax and use is identical to GameConnection.

// Connect to the CMS server and ask it what kind of server to be.
$CMSConnection = new PeerConnection(CMSConnection);
$CMSConnection.setConnectArgs($Pref::Server::CMSName);
$CMSConnection.setJoinPassword($Pref::Server::CMSPassword);
$CMSConnection.connect($Pref::Server::CMSAddress);

On the acceptor side, the connection is created but not automatically named, so it can be "lost" if you're not careful. I highly recommend that one of the tasks of onConnect be to store the new connection in a safe place; the included example stores all accepted connections into the SimGroup PeerGroup.

I think that's it. Have fun with this, and I hope it helps someone besides me!