Synchronize customization, gadgets, items, and shops

Multiplayer/Components/IdMonoBehaviour.cs

@@ -19,8 +19,6 @@ public T NetId {
         set {
             if (_netId.Equals(value))
                 return;
-            if ((_netId as dynamic).CompareTo(default(T)) != 0)
-                idPool.ReleaseId(_netId);
             Register(value);
         }
     }
@@ -29,7 +27,7 @@ public T NetId {
 
     protected static bool Get(T netId, out IdMonoBehaviour<T, I> obj)
     {
-        if (indexToObject.TryGetValue(netId, out obj))
+        if (indexToObject.TryGetValue(netId, out obj) && obj != null)
             return true;
         obj = null;
         if ((netId as dynamic).CompareTo(default(T)) != 0)
@@ -39,7 +37,7 @@ protected static bool Get(T netId, out IdMonoBehaviour<T, I> obj)
 
     protected static bool TryGet(T netId, out IdMonoBehaviour<T, I> obj)
     {
-        if (indexToObject.TryGetValue(netId, out obj))
+        if (indexToObject.TryGetValue(netId, out obj) && obj != null)
             return true;
 
         obj = null;
@@ -55,13 +53,26 @@ protected virtual void Awake()
 
     public void Register(T id)
     {
+        if (_netId.Equals(id) && indexToObject.TryGetValue(id, out var existing) && ReferenceEquals(existing, this))
+            return;
+        Unregister();
         _netId = id;
-        indexToObject[id] = this;
+        if (!id.Equals(default(T)))
+            indexToObject[id] = this;
+    }
+
+    private void Unregister()
+    {
+        if (!_netId.Equals(default(T)) && indexToObject.TryGetValue(_netId, out var current) && ReferenceEquals(current, this))
+        {
+            indexToObject.Remove(_netId);
+            idPool.ReleaseId(_netId);
+        }
     }
 
     protected virtual void OnDestroy()
     {
-        idPool.ReleaseId(NetId);
+        Unregister();
         if (!UnloadWatcher.isUnloading)
             return;
         idPool.Reset();

Multiplayer/Components/Networking/NetworkLifecycle.cs

@@ -4,6 +4,7 @@
 using MPAPI;
 using Multiplayer.API;
 using Multiplayer.Components.Networking.UI;
+using Multiplayer.Components.Networking.World;
 using Multiplayer.Networking.Data;
 using Multiplayer.Networking.Managers.Client;
 using Multiplayer.Networking.Managers.Server;
@@ -33,6 +34,7 @@ public class NetworkLifecycle : SingletonBehaviour<NetworkLifecycle>
     public NetworkClient Client { get; private set; }
 
     public uint Tick { get; internal set; }
+    public uint SynchronizedTick => IsServerRunning || clientTickSynchronized ? Tick : 0;
     public Action<uint> OnTick;
 
     public bool IsServerRunning => Server?.IsRunning ?? false;
@@ -46,6 +48,42 @@ public class NetworkLifecycle : SingletonBehaviour<NetworkLifecycle>
     private NetworkStatsGui Stats;
     private readonly ExecutionTimer tickTimer = new();
     private readonly ExecutionTimer tickWatchdog = new(0.25f);
+    private bool clientTickSynchronized;
+    private uint clientTicksToHold;
+
+    public static int SignedTickDelta(uint newer, uint older) => unchecked((int)(newer - older));
+
+    public float SecondsSinceTick(uint sampleTick)
+    {
+        return Mathf.Max(0f, SignedTickDelta(Tick, sampleTick) / (float)TICK_RATE);
+    }
+
+    internal void SynchronizeClientTick(uint serverTick, int oneWayLatencyMs)
+    {
+        uint latencyTicks = (uint)Mathf.Max(0, Mathf.RoundToInt(oneWayLatencyMs / 1000f * TICK_RATE));
+        uint estimatedServerTick = unchecked(serverTick + latencyTicks);
+
+        if (!clientTickSynchronized)
+        {
+            Tick = estimatedServerTick;
+            clientTickSynchronized = true;
+            clientTicksToHold = 0;
+            return;
+        }
+
+        int drift = SignedTickDelta(estimatedServerTick, Tick);
+        if (drift > 0)
+        {
+            Tick = estimatedServerTick;
+            clientTicksToHold = 0;
+        }
+        else if (drift < 0)
+        {
+            // Never rewind the public tick: pause local generation briefly while
+            // the server clock catches up. Cap one correction against bad samples.
+            clientTicksToHold = (uint)Math.Min(-(long)drift, TICK_RATE * 2L);
+        }
+    }
 
     /// <summary>
     ///     Whether the provided ITransportPeer is the host.
@@ -126,6 +164,8 @@ public bool StartServer(IDifficulty difficulty)
         if (Server != null)
             throw new InvalidOperationException("NetworkManager already exists!");
 
+        ShopPurchaseCoordinator.ResetSessionState();
+
         if (!IsSinglePlayer)
         {
             if (serverData != null)
@@ -159,6 +199,12 @@ public void StartClient(string address, int port, string password, bool isSingle
     {
         if (Client != null)
             throw new InvalidOperationException("NetworkManager already exists!");
+        if (!IsServerRunning)
+        {
+            clientTickSynchronized = false;
+            clientTicksToHold = 0;
+        }
+
         NetworkClient client = new(Multiplayer.Settings, isSinglePlayer);
         client.Start(address, port, password, isSinglePlayer, onDisconnect);
 
@@ -175,13 +221,18 @@ private IEnumerator PollEvents()
     {
         while (!UnloadWatcher.isQuitting)
         {
-            Tick++;
+            bool advanceTick = IsServerRunning || clientTicksToHold == 0;
+            if (advanceTick)
+                Tick++;
+            else
+                clientTicksToHold--;
+
             tickTimer.Start();
 
             tickWatchdog.Start();
             try
             {
-                if (!UnloadWatcher.isUnloading && !UnloadWatcher.isQuitting && !IsReturningToMenu)
+                if (advanceTick && !UnloadWatcher.isUnloading && !UnloadWatcher.isQuitting && !IsReturningToMenu)
                     OnTick?.Invoke(Tick);
             }
             catch (Exception e)
@@ -230,6 +281,7 @@ private void TickManager(NetworkManager manager)
     public void Stop()
     {
         Stats?.Hide();
+        ShopPurchaseCoordinator.ResetSessionState();
 
         if (Server != null)
         {

Multiplayer/Components/Networking/Player/NetworkedPlayer.cs

@@ -94,6 +94,9 @@ public string DisplayName
     private Quaternion targetRotation;
     private Vector2 moveDir;
     private Vector2 targetMoveDir;
+    private uint lastTrackingTick;
+    private bool hasTrackingTick;
+    private float pendingTrackingAge;
 
     private float currentLeanAngle;
     private float angleSmoothRefVel;
@@ -281,7 +284,11 @@ protected void Update()
             return;
         }
 
-        float t = Time.deltaTime * LERP_SPEED;
+        // Consume packet age once so smoothing does not add its full delay on top
+        // of the time this sample has already spent in transit.
+        float interpolationDelta = Time.deltaTime + pendingTrackingAge;
+        pendingTrackingAge = 0f;
+        float t = 1f - Mathf.Exp(-LERP_SPEED * interpolationDelta);
 
         Vector3 position = Vector3.Lerp(
             IsOnCar ? selfTransform.localPosition : selfTransform.position,
@@ -375,7 +382,7 @@ private void ApplySpineAndHeadRotation()
             // Side lean is always spinning around the root's global FORWARD axis
             Quaternion leanOffset = Quaternion.AngleAxis(currentLeanAngle, selfTransform.forward);
 
-            // Directly assign the uniform world rotation 
+            // Directly assign the uniform world rotation
             spineTransform.rotation = leanOffset * currentModelSpineBase;
         }
 
@@ -413,6 +420,23 @@ private void ApplyHandTracking()
     /// <param name="trackingData"></param>
     /// <param name="posture"></param>
     /// <param name="movePacketIsOnCar"></param>
+    public bool TryAcceptTrackingTick(uint sampleTick)
+    {
+        if (sampleTick == 0)
+            return true;
+
+        if (hasTrackingTick && NetworkLifecycle.SignedTickDelta(sampleTick, lastTrackingTick) < 0)
+            return false;
+
+        lastTrackingTick = sampleTick;
+        hasTrackingTick = true;
+        pendingTrackingAge = Mathf.Clamp(
+            NetworkLifecycle.Instance.SecondsSinceTick(sampleTick),
+            0f,
+            0.25f);
+        return true;
+    }
+
     public void UpdatePosition(PlayerTrackingData trackingData, PlayerPostureFlags posture, bool movePacketIsOnCar)
     {
         if (trackingData.Position.HasValue)

Multiplayer/Components/Networking/Train/NetworkedTrainCar.cs

@@ -47,6 +47,8 @@ public static bool TryGet(ushort netId, out NetworkedTrainCar obj)
         return b;
     }
 
+    public static IEnumerable<NetworkedTrainCar> GetAll() => trainCarsToNetworkedTrainCars.Values;
+
     public static bool TryGet(ushort netId, out TrainCar trainCar)
     {
         bool b = TryGet(netId, out NetworkedTrainCar networkedTrainCar);
@@ -162,6 +164,9 @@ static string GetFuse(uint netId)
 
     public string CurrentID { get; private set; }
     public TrainCar TrainCar;
+    public bool HasAttachedCustomizations => TrainCar?.Customization != null &&
+        ((TrainCar.Customization.Customizers?.Count ?? 0) > 0 || TrainCar.Customization.HoleCount > 0);
+    public bool IsInteriorPinnedForNetworkSync => interiorSyncLeaseCount > 0;
     public uint TicksSinceSync = uint.MaxValue;
 
     public uint lastTickProcessed = 0;
@@ -184,6 +189,7 @@ static string GetFuse(uint netId)
     private readonly Dictionary<string, float> lastSentTrainDamages = [];
 
     private InteriorControlsManager interiorControlsManager;
+    private int interiorSyncLeaseCount;
     private readonly Dictionary<ControlImplBase, Action<ValueChangedEventArgs>> scrollableControlDelegates = [];
     private Dictionary<InteriorControlsManager.ControlType, OverridableBaseControl> controlTypeToControl = [];
     private readonly Dictionary<uint, OverridableBaseControl> portToBaseControl = [];
@@ -482,50 +488,40 @@ protected void Start()
         NetworkLifecycle.Instance?.Client.SendTrainSyncRequest(NetId);
     }
 
+    private Coroutine interiorHookRoutine;
+
     private void OnTrainCarInteriorLoaded(GameObject interior)
     {
-        Multiplayer.LogDebug(() => $"OnTrainCarInteriorLoaded() {CurrentID}, interior is null: {interior == null}");
-
-        StartCoroutine(WaitForInterior());
+        // Streaming can unload the cab while controls are still initializing.
+        // Cancel work for the previous instance before binding the new one.
+        OnTrainCarInteriorUnloaded(interior);
+        if (interior != null)
+            interiorHookRoutine = StartCoroutine(WaitForInterior(interior));
     }
 
-    private IEnumerator WaitForInterior()
+    private IEnumerator WaitForInterior(GameObject interior)
     {
-        float time = Time.time;
-        interiorControlsManager = null;
-
-        yield return new WaitUntil
-        (
-            () =>
-            {
-                return TrainCar?.loadedInterior != null || Time.time - time > INTERIOR_CONTROLS_TIMEOUT;
-            }
-        );
-
-        yield return new WaitForFixedUpdate();
-
-        if (TrainCar?.loadedInterior == null)
+        float deadline = Time.time + INTERIOR_CONTROLS_TIMEOUT;
+        InteriorControlsManager controls = null;
+        while (interior != null && !interior.TryGetComponent(out controls) && Time.time < deadline)
+            yield return null;
+        if (interior == null)
+            yield break;
+        if (controls == null)
         {
-            Multiplayer.LogError($"TrainCar {CurrentID} failed to load an interior");
+            Multiplayer.LogWarning($"TrainCar {CurrentID} interior has no controls manager");
             yield break;
         }
-
-        time = Time.time;
-
-        yield return new WaitUntil
-        (
-            () =>
-            {
-                return TrainCar.loadedInterior.TryGetComponent<InteriorControlsManager>(out interiorControlsManager) || Time.time - time > INTERIOR_CONTROLS_TIMEOUT;
-            }
-        );
-
-        CoroutineManager.Instance.StartCoroutine(HookControls(interiorControlsManager));
+        interiorControlsManager = controls;
+        yield return HookControls(controls);
+        interiorHookRoutine = null;
     }
 
     private IEnumerator HookControls(InteriorControlsManager interiorControlsManager)
     {
-        yield return new WaitUntil(() => interiorControlsManager.Initialized);
+        yield return new WaitUntil(() => interiorControlsManager == null || interiorControlsManager.Initialized);
+        if (interiorControlsManager == null)
+            yield break;
 
         Multiplayer.LogDebug(() => $"HookControls() Hooking controls for car {CurrentID}, found {interiorControlsManager?.controls?.Count} controls");
 
@@ -535,6 +531,11 @@ private IEnumerator HookControls(InteriorControlsManager interiorControlsManager
             var control = kvp.Value;
             var key = kvp.Key;
 
+            // Controls without an override port (e.g. the handbrake) use their
+            // dedicated synchronization path, not control-port authority.
+            if (control.overridableBaseControl == null)
+                continue;
+
             float timeOut = Time.time;
             yield return new WaitUntil
             (
@@ -600,6 +601,11 @@ private IEnumerator HookControls(InteriorControlsManager interiorControlsManager
     private void OnTrainCarInteriorUnloaded(GameObject interior)
     {
         Multiplayer.LogDebug(() => $"OnTrainCarInteriorUnloaded() {CurrentID}");
+        if (interiorHookRoutine != null)
+        {
+            StopCoroutine(interiorHookRoutine);
+            interiorHookRoutine = null;
+        }
 
         foreach (var control in controlToPortNetId.Keys)
         {
@@ -628,6 +634,7 @@ private void OnTrainCarInteriorUnloaded(GameObject interior)
                 kvp.Key.ValueChanged -= kvp.Value;
         }
 
+        scrollableControlDelegates.Clear();
         portNetIdToControl.Clear();
         controlToPortNetId.Clear();
 
@@ -641,6 +648,13 @@ public void OnDisable()
         if (UnloadWatcher.isQuitting)
             return;
 
+        OnTrainCarInteriorUnloaded(null);
+        if (TrainCar != null)
+        {
+            TrainCar.InteriorLoaded -= OnTrainCarInteriorLoaded;
+            TrainCar.InteriorAboutToBeUnloaded -= OnTrainCarInteriorUnloaded;
+        }
+
         //Clean dictionaries
         trainCarsToNetworkedTrainCars.Remove(TrainCar);
         trainCarIdToNetworkedTrainCars.Remove(CurrentID);
@@ -1186,6 +1200,25 @@ public void Server_PlayerOnCar(ServerPlayer player)
 
         serverPlayersInCar.Add(player);
         TrainCar?.visitChecker?.OnPlayerCarChanged(TrainCar);
+
+        // The vanilla ECS interior streamer is based on the host's local camera and
+        // can ignore CarVisitChecker's remote-player state. Customization components
+        // live in the instantiated interior, so explicitly load it for remote users.
+        if (TrainCar != null && !TrainCar.IsInteriorLoaded)
+            TrainCar.LoadInterior();
+    }
+
+    public void BeginInteriorNetworkSync()
+    {
+        interiorSyncLeaseCount++;
+        if (TrainCar != null && !TrainCar.IsInteriorLoaded)
+            TrainCar.LoadInterior();
+    }
+
+    public void EndInteriorNetworkSync()
+    {
+        if (interiorSyncLeaseCount > 0)
+            interiorSyncLeaseCount--;
     }
 
     public void Server_RemovePlayer(ServerPlayer player)