Characters

Game/Scripts/Networking/SteamP2PTransport.cs

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+using System;
+using Steamworks;
+using UnityEngine;
+
+namespace MegaKoop.Game.Networking
+{
+    /// <summary>
+    /// Low level Steam P2P messaging helper. Prepends a byte message type header for easy routing.
+    /// </summary>
+    public class SteamP2PTransport : MonoBehaviour
+    {
+        public event Action<NetworkMessage> MessageReceived;
+
+        [SerializeField] private EP2PSend defaultSendType = EP2PSend.k_EP2PSendReliable;
+        [SerializeField] private int listenChannel = 0;
+
+        private byte[] receiveBuffer = new byte[8192];
+        private CSteamID activeLobby = CSteamID.Nil;
+
+        private void Update()
+        {
+            if (!SteamBootstrap.IsInitialized)
+            {
+                return;
+            }
+
+            PumpIncomingPackets();
+        }
+
+        public void SetActiveLobby(CSteamID lobbyId)
+        {
+            activeLobby = lobbyId;
+        }
+
+        public void Send(CSteamID recipient, NetworkMessageType type, byte[] payload, EP2PSend sendType = EP2PSend.k_EP2PSendReliable)
+        {
+            if (!SteamBootstrap.IsInitialized)
+            {
+                return;
+            }
+
+            int payloadLength = payload != null ? payload.Length : 0;
+            byte[] packet = new byte[payloadLength + 1];
+            packet[0] = (byte)type;
+            if (payloadLength > 0)
+            {
+                Buffer.BlockCopy(payload, 0, packet, 1, payloadLength);
+            }
+
+            bool sent = SteamNetworking.SendP2PPacket(recipient, packet, (uint)packet.Length, sendType, listenChannel);
+            if (!sent)
+            {
+                Debug.LogWarning("[SteamP2PTransport] Failed to send packet to " + recipient);
+            }
+        }
+
+        public void Broadcast(NetworkMessageType type, byte[] payload, EP2PSend sendType = EP2PSend.k_EP2PSendReliable)
+        {
+            if (activeLobby == CSteamID.Nil)
+            {
+                return;
+            }
+
+            int members = SteamMatchmaking.GetNumLobbyMembers(activeLobby);
+            CSteamID self = SteamUser.GetSteamID();
+
+            for (int i = 0; i < members; i++)
+            {
+                CSteamID member = SteamMatchmaking.GetLobbyMemberByIndex(activeLobby, i);
+                if (member == self)
+                {
+                    continue;
+                }
+
+                Send(member, type, payload, sendType);
+            }
+        }
+
+        private void PumpIncomingPackets()
+        {
+            while (SteamNetworking.IsP2PPacketAvailable(out uint packetSize, listenChannel))
+            {
+                if (packetSize == 0)
+                {
+                    continue;
+                }
+
+                if (packetSize > receiveBuffer.Length)
+                {
+                    receiveBuffer = new byte[(int)packetSize];
+                }
+
+                if (SteamNetworking.ReadP2PPacket(receiveBuffer, (uint)receiveBuffer.Length, out uint bytesRead, out CSteamID remote, listenChannel))
+                {
+                    SteamNetworking.AcceptP2PSessionWithUser(remote);
+
+                    if (bytesRead == 0)
+                    {
+                        continue;
+                    }
+
+                    NetworkMessageType type = (NetworkMessageType)receiveBuffer[0];
+                    byte[] payload = new byte[Mathf.Max(0, (int)bytesRead - 1)];
+                    if (bytesRead > 1)
+                    {
+                        Buffer.BlockCopy(receiveBuffer, 1, payload, 0, (int)bytesRead - 1);
+                    }
+
+                    MessageReceived?.Invoke(new NetworkMessage(type, payload, remote.m_SteamID));
+                }
+            }
+        }
+    }
+}