Monster syncing fixes:

- clients freeze and disable AI characters if no updates have been received in a while (due to the monster being far away from player-controlled characters at the servers side for example)
- server disables AI characters that are too far for updates to be sent to clients (-> targets of monster missions can't swim away from the spawnpos and cause the clients' sonars to point to an incorrect position)

Subsurface/Source/Characters/AICharacter.cs

@@ -51,6 +51,22 @@ namespace Barotrauma
 
             if (Controlled == this || !aiController.Enabled) return;
 
+            if (GameMain.Client != null)
+            {
+                //freeze AI characters if more than 1 seconds have passed since last update from the server
+                if (lastRecvPositionUpdateTime < NetTime.Now - 1.0f)
+                {
+                    AnimController.Frozen = true;
+                    memPos.Clear();
+                    //hide after 2 seconds
+                    if (lastRecvPositionUpdateTime < NetTime.Now - 2.0f)
+                    {
+                        Enabled = false;
+                        return;
+                    }
+                }
+            }
+
             if (soundTimer > 0)
             {
                 soundTimer -= deltaTime;
@@ -149,11 +165,12 @@ namespace Barotrauma
         public override bool ReadNetworkData(NetworkEventType type, NetIncomingMessage message, float sendingTime, out object data)
         {
             data = null;
-            Enabled = true;
 
             //server doesn't accept AICharacter updates from the clients
             if (GameMain.Server != null) return false;
 
+            Enabled = true;
+
             switch (type)
             {
                 case NetworkEventType.KillCharacter:
@@ -198,6 +215,13 @@ namespace Barotrauma
                 case NetworkEventType.EntityUpdate:
                     if (sendingTime <= LastNetworkUpdate) return false;
 
+                    if (GameMain.Client != null)
+                    {
+                        lastRecvPositionUpdateTime = (float)NetTime.Now;
+                        AnimController.Frozen = false;
+                        Enabled = true;
+                    }
+
                     bool playerControlled = message.ReadBoolean();
                     if (playerControlled)
                     {

Subsurface/Source/Characters/Character.cs

@@ -20,14 +20,10 @@ namespace Barotrauma
         
         public static bool DisableControls;
 
-        private UInt32 netStateID;
-        public UInt32 NetStateID
-        {
-            get { return netStateID; }
-        }
-
         protected List<PosInfo> memPos = new List<PosInfo>();
 
+        protected float lastRecvPositionUpdateTime;
+
         private bool networkUpdateSent;
         
         //the Character that the player is currently controlling
@@ -58,6 +54,7 @@ namespace Barotrauma
             }
             set
             {
+                if (value == enabled) return;
                 enabled = value;
 
                 foreach (Limb limb in AnimController.Limbs)
@@ -757,13 +754,6 @@ namespace Barotrauma
             //        AnimController.TargetDir = Direction.Right;
             //    }
             //}
-            //else if (GameMain.Client != null && Character.controlled != this)
-            //{
-            //    if (memPos.Count > 0)
-            //    {
-            //        AnimController.TargetDir = memPos[0].Direction;
-            //    }
-            //}
 
             if (attackCoolDown >0.0f)
             {
@@ -1957,7 +1947,12 @@ namespace Barotrauma
 
                     break;
                 case NetworkEventType.EntityUpdate:
-                    if (GameMain.Client != null) Enabled = true;
+                    if (GameMain.Client != null)
+                    {
+                        lastRecvPositionUpdateTime = (float)NetTime.Now;
+                        AnimController.Frozen = false;
+                        Enabled = true;
+                    }
 
                     Vector2 relativeCursorPos = Vector2.Zero;
 

Subsurface/Source/Networking/GameServer.cs

@@ -472,18 +472,19 @@ namespace Barotrauma.Networking
             //    }
             //}
 
+            float ignoreDistance = FarseerPhysics.ConvertUnits.ToDisplayUnits(NetConfig.CharacterIgnoreDistance);
+
             foreach (Character c in Character.CharacterList)
             {
-                if (c.IsDead) continue;
-
                 if (c is AICharacter)
                 {
-                    //todo: take multiple subs into account
-                    //Vector2 diff = c.WorldPosition - Submarine.MainSub.WorldPosition;
-
-                    //if (FarseerPhysics.ConvertUnits.ToSimUnits(diff.Length()) > NetConfig.CharacterIgnoreDistance) continue;
+                    c.Enabled = 
+                       (myCharacter != null && Vector2.Distance(myCharacter.WorldPosition, c.WorldPosition) < ignoreDistance) ||
+                        Character.CharacterList.Any(c2 => c2.IsRemotePlayer && Vector2.Distance(c2.WorldPosition, c.WorldPosition) < ignoreDistance);
                 }
 
+                if (c.IsDead) continue;
+
                 new NetworkEvent(NetworkEventType.ImportantEntityUpdate, c.ID, false);
             }