iOSMultiplayerTemplate / P2PKit

P2PKit is a Bluetooth or WiFi Networking framework for hackathons! It is uses Apple's Multipeer Connectivity and works for all iOS, including Vision Pro, iPhone, and iPad.

Features

• Offline data passing! For best performance across real devices, disable WiFi to use bluetooth connection.
• Automatic retrying when peers disconnect.
• Easy APIs for sending/receiving Codable data, with callbacks or with SwiftUI.
• Game Demo that uses P2PKit.
• APIs for setting/observing one device as host and the rest as followers.
• APIs for resetting session, changing the display name, and debugging.

Game Demo

You're the mallet with the star. When the white puck enters a hole, the last person to touch the white puck with their mallet scores a point!

P2PKitDemoPhone.mp4

APIs

3.Data.Passing.mov

Use P2PSynced to sync Codable data

P2PSynced is the easiest way to sync data across devices.

let syncedRoom = P2PSynced<GameRoom>(
        name: "GameRoom",
        initial: GameRoom(),
        writeAccess: .hostOnly, // Optional param. Defaults to .everyone has write access. If using .hostOnly, set host with `P2PNetwork.makeMeHost()`.
        reliable: true) // Optional param. Defaults to false. Reliable sending is slower but preserves order and doesn't drop messages.

// GET data
syncedRoom.onReceiveSync = { gameRoom in }

// SEND DATA
syncedRoom.value = GameRoom(...) 

Use P2PSyncedObservable with Swift UI

Use P2PSyncedObservable, a light wrapper around P2PSynced, with SwiftUI.

In this example, an Int value is sent between devices to sync a counter.

struct SyncedCounter: View {
    @StateObject private var counter = P2PSyncedObservable(name: "SyncedCounter", initial: 1)
    
    var body: some View {
        Button("+ 1") {
            counter.value = counter.value + 1 // SET VALUE
        }
        Text("Counter: \(counter.value)") // RECEIVE VALUE
    }
}

Similarily, in the SyncedCircles example, the Codable object SendableCircle, is synced across all devices.

@StateObject var blueCircle = P2PSyncedObservable(name: "blue", initial: SendableCircle(point: CGPoint(x: 300, y: -26)))
@StateObject var greenCircle = P2PSyncedObservable(name: "green", initial: SendableCircle(point: CGPoint(x: 260, y: -10)))

// RECEIVE
let sendableCircle = blueCircle.value

// SEND
blueCircle.value = SendableCircle(point: newPoint)

Use P2PEventService to send/receive Codable events

let malletDraggedEvents = P2PEventService<MalletDragEvent>("MalletDrag")

// RECEIVE
malletDraggedEvents.onReceive { eventInfo, malletDragEvent, json, sender in
  // Handle malletDragEvent
}

// SEND
malletDraggedEvents.send(payload: MalletDragEvent(...), reliable: false)

P2PNetworkDelegate

Get myself and connected peers.

let myPeer: Peer = P2PNework.myPeer

let connectedPeers: [Peer] = P2PNework.connectedPeers

Observe peer updates with P2PNetworkPeerDelegate. When connectedPeers update, the p2pNetwork(didUpdate peer: Peer) handler will be called.

protocol P2PNetworkPeerDelegate: AnyObject {
    func p2pNetwork(didUpdate peer: Peer)
    func p2pNetwork(didUpdateHost host: Peer?)
}

P2PNework.addPeerDelegate(self)
P2PNework.removePeerDelegate(self)

(Optional) Reset the session.

P2PNework.resetSession("New Display Name") // Change display name.
P2PNework.resetSession(nil) // Keep current display name.

(Optional) Get and set the host for all connected devices. Not all games need a host.

let currentHost: Peer? = P2PNework.host

P2PNework.makeMeHost()

Bonus: Host Features

Host Selection

• Whoever taps "Create Room" acts as the host server with the game's source of truth, streaming game physics to everyone.
• Non-hosts disconnect and reconnects automatically, and their score will resume.
• When a host disconnects, other players get the "Continue Room" button, and the first player to tap that button becomes the host.
• Any previous host will accept the new host.

2.resume.game.mp4

Host resumes data

When the current device connects to a host, P2PSynced and P2PSyncedObservable will sync the latest data from the host.

4.Host.resumes.data.mp4