Reduced memory allocations in the Observer system

Author: TwoTenPvP

MLAPI/MonoBehaviours/Core/NetworkedObject.cs

@@ -134,6 +134,7 @@ public bool isSpawned
         internal bool? sceneObject = null;
 
         public HashSet<uint> observers = new HashSet<uint>();
+        private HashSet<uint> previousObservers = new HashSet<uint>();
 
         internal void RebuildObservers(uint? clientId = null)
         {
@@ -155,15 +156,16 @@ internal void RebuildObservers(uint? clientId = null)
             }
             else
             {
-                HashSet<uint> previousObservers = new HashSet<uint>(observers);
-                HashSet<uint> newObservers = new HashSet<uint>();
+                previousObservers.Clear();
+                foreach (var item in observers)
+                    previousObservers.Add(item);
+                observers.Clear();
                 bool update = false;
                 for (int i = 0; i < childNetworkedBehaviours.Count; i++)
                 {
-                    bool changed = childNetworkedBehaviours[i].OnRebuildObservers(newObservers);
+                    bool changed = childNetworkedBehaviours[i].OnRebuildObservers(observers);
                     if (changed)
                     {
-                        observers = newObservers;
                         update = true;
                         break;
                     }
@@ -174,8 +176,8 @@ internal void RebuildObservers(uint? clientId = null)
                     {
                         if (pair.Key == NetworkingManager.singleton.NetworkConfig.NetworkTransport.HostDummyId)
                             continue;
-                        if ((previousObservers.Contains(pair.Key) && !newObservers.Contains(pair.Key)) ||
-                            (!previousObservers.Contains(pair.Key) && newObservers.Contains(pair.Key)))
+                        if ((previousObservers.Contains(pair.Key) && !observers.Contains(pair.Key)) ||
+                            (!previousObservers.Contains(pair.Key) && observers.Contains(pair.Key)))
                         {
                             //Something changed for this client.
                             using (BitWriter writer = new BitWriter())
@@ -189,6 +191,11 @@ internal void RebuildObservers(uint? clientId = null)
                         }
                     }
                 }
+                else
+                {
+                    foreach (var item in previousObservers)
+                        observers.Add(item);
+                }
             }
         }
 

MLAPI/MonoBehaviours/Prototyping/NetworkedProximity.cs

@@ -47,6 +47,8 @@ public override bool OnCheckObserver(uint newClientId)
             return (pos - transform.position).magnitude < Range;
         }
 
+        private Collider[] colliders = new Collider[32];
+        private Collider2D[] colliders2d = new Collider2D[32];
         public override bool OnRebuildObservers(HashSet<uint> observers)
         {
             if (ForceHidden)
@@ -61,21 +63,35 @@ public override bool OnRebuildObservers(HashSet<uint> observers)
             {
                 case CheckMethod.Physics3D:
                     {
-                        var hits = Physics.OverlapSphere(transform.position, Range);
-                        for (int i = 0; i < hits.Length; i++)
+                        int hits = Physics.OverlapSphereNonAlloc(transform.position, Range, colliders);
+                        //We check if it's equal to since the OverlapSphereNonAlloc only returns what it actually wrote, not what it found.
+                        if (hits >= colliders.Length)
                         {
-                            var uv = hits[i].GetComponent<NetworkedObject>();
+                            //Resize colliders array
+                            colliders = new Collider[(int)((hits + 2)* 1.3f)];
+                            hits = Physics.OverlapSphereNonAlloc(transform.position, Range, colliders);
+                        }
+                        for (int i = 0; i < hits; i++)
+                        {
+                            var uv = colliders[i].GetComponent<NetworkedObject>();
                             if (uv != null && uv.isPlayerObject)
                                 observers.Add(uv.OwnerClientId);
                         }
                         return true;
                     }
                 case CheckMethod.Physics2D:
                     {
-                        var hits = Physics2D.OverlapCircleAll(transform.position, Range);
-                        for (int i = 0; i < hits.Length; i++)
+                        int hits = Physics2D.OverlapCircleNonAlloc(transform.position, Range, colliders2d);
+                        //We check if it's equal to since the OverlapSphereNonAlloc only returns what it actually wrote, not what it found.
+                        if (hits >= colliders.Length)
+                        {
+                            //Resize colliders array
+                            colliders2d = new Collider2D[(int)((hits + 2) * 1.3f)];
+                            hits = Physics2D.OverlapCircleNonAlloc(transform.position, Range, colliders2d);
+                        }
+                        for (int i = 0; i < hits; i++)
                         {
-                            var uv = hits[i].GetComponent<NetworkedObject>();
+                            var uv = colliders2d[i].GetComponent<NetworkedObject>();
                             if (uv != null && (uv.isPlayerObject))
                                 observers.Add(uv.OwnerClientId);
                         }