chore: added an experimental ordered fast list class

They still do generate a lot of garbage but with boxed value pools I made the boxes reusable, it still does generate garbage through the delegate creation, gotta find a solution for them later

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "Engine.Serializers/YamlDotNet"]
+[submodule "Engine.Integration/YamlDotNet"]
-	path = Engine.Serializers/YamlDotNet
+	path = Engine.Integration/YamlDotNet
 	url = git@github.com:Syntriax/YamlDotNet.git

Engine.Core/Abstract/Assignable/IAssignable.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the class implementing it has Assignable fields that are necessary for the engine to work properly.

Engine.Core/Abstract/Assignable/IHasBehaviourController.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the object is an <see cref="IAssignable"/> with an assignable <see cref="IBehaviourController"/> field.

Engine.Core/Abstract/Assignable/IHasEntity.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the object is an <see cref="IAssignable"/> with an assignable <see cref="IEntity"/> field.

Engine.Core/Abstract/Assignable/IHasStateEnable.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the object is an <see cref="IAssignable"/> with an assignable <see cref="IStateEnable"/> field.

Engine.Core/Abstract/Assignable/IHasUniverse.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the object is an <see cref="IAssignable"/> with an assignable <see cref="IUniverse"/> field.

Engine.Core/Abstract/Assignable/IHasUniverseObject.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Indicates the object is an <see cref="IAssignable"/> with an assignable <see cref="IUniverseObject"/> field.

Engine.Core/Abstract/IActive.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an entity which can be active or not.

Engine.Core/Abstract/IBehaviour.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a behaviour that any object in the engine that might use to interact with itself or other objects. 

Engine.Core/Abstract/IBehaviour2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public interface IBehaviour2D : IBehaviour
 {

Engine.Core/Abstract/IBehaviourCollector.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a collector for the class type of <typeparamref name="T"/>.

Engine.Core/Abstract/IBehaviourController.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a controller for managing <see cref="IBehaviour"/>s. Connected to an <see cref="IUniverseObject"/>.

Engine.Core/Abstract/ICamera2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a 2D camera in the engine.

Engine.Core/Abstract/ICoroutineYield.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public interface ICoroutineYield
 {

Engine.Core/Abstract/IEntity.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a basic entity in the engine.

Engine.Core/Abstract/IInitializable.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an entity that can be initialized and finalized. This information is useful for objects we know that are not in use and can be either recycled or dropped for garbage collection.

Engine.Core/Abstract/INameable.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an entity with a name.

Engine.Core/Abstract/IStateEnable.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an entity with an enable state that can be toggled.

Engine.Core/Abstract/ITransform2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents the transformation properties of an object such as position, scale, and rotation in 2D space.

Engine.Core/Abstract/IUniverse.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a universe responsible for managing <see cref="IUniverseObject"/>s.
@@ -37,11 +37,21 @@ public interface IUniverse : IEntity, IEnumerable<IUniverseObject>
     /// </summary>
     Event<IUniverse> OnPostDraw { get; }
 
+    /// <summary>
+    /// Event triggered when a <see cref="IUniverseObject"/> is about to be registered to the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse, UniverseObjectRegisteredArguments> OnPreUniverseObjectRegistered { get; }
+
     /// <summary>
     /// Event triggered when a <see cref="IUniverseObject"/> is registered to the <see cref="IUniverse"/>.
     /// </summary>
     Event<IUniverse, UniverseObjectRegisteredArguments> OnUniverseObjectRegistered { get; }
 
+    /// <summary>
+    /// Event triggered when a <see cref="IUniverseObject"/> is about to be unregistered from the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse, UniverseObjectUnRegisteredArguments> OnPreUniverseObjectUnRegistered { get; }
+
     /// <summary>
     /// Event triggered when a <see cref="IUniverseObject"/> is unregistered from the <see cref="IUniverse"/>.
     /// </summary>

Engine.Core/Abstract/IUniverseObject.cs

@@ -1,13 +1,13 @@
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an <see cref="IEntity"/> that can enter and exit a universe within the <see cref="IUniverse"/> system.
 /// This interface allows for tracking the object's presence in the universe and provides events 
 /// for notifying when the see enters or exits the universe.
 /// </summary>
-public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourController, IEnumerable<IUniverseObject>
+public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourController
 {
     /// <summary>
     /// Event triggered when the <see cref="IUniverseObject"/> enters the universe.
@@ -47,7 +47,7 @@ public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourCon
     /// <summary>
     /// The parent <see cref="IUniverseObject"/> of the <see cref="IUniverseObject"/>.
     /// </summary>
-    IUniverseObject? Parent { get; }
+    IUniverseObject? Parent { get; set; }
 
     /// <summary>
     /// The <see cref="IUniverseObject"/>s that have this <see cref="IUniverseObject"/> as their <see cref="Parent"/>.
@@ -75,12 +75,6 @@ public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourCon
     /// </returns>
     internal bool ExitUniverse();
 
-    /// <summary>
-    /// Sets the parent <see cref="IUniverseObject"/> of this <see cref="IUniverseObject"/>.
-    /// </summary>
-    /// <param name="universeObject">The parent <see cref="IUniverseObject"/> to set.</param>
-    void SetParent(IUniverseObject? universeObject);
-
     /// <summary>
     /// Adds a child <see cref="IUniverseObject"/> to this <see cref="IUniverseObject"/>.
     /// </summary>

Engine.Core/ActiveBehaviourCollectorSorted.cs

@@ -1,67 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace Syntriax.Engine.Core;
-
-public class ActiveBehaviourCollectorSorted<T> : ActiveBehaviourCollector<T> where T : class, IBehaviour
-{
-    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
-
-    private IComparer<T>? _sortBy = null;
-    public IComparer<T>? SortBy
-    {
-        get => _sortBy;
-        set
-        {
-            _sortBy = value;
-
-            if (value is not null)
-                activeBehaviours.Sort(value);
-        }
-    }
-
-    protected override void AddBehaviour(T behaviour)
-    {
-        if (SortBy is null)
-        {
-            activeBehaviours.Add(behaviour);
-            return;
-        }
-
-        int insertionIndex = activeBehaviours.BinarySearch(behaviour, SortBy);
-
-        if (insertionIndex < 0)
-            insertionIndex = ~insertionIndex;
-
-        activeBehaviours.Insert(insertionIndex, behaviour);
-    }
-
-    protected override void OnBehaviourAdd(IBehaviour behaviour)
-    {
-        behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
-    }
-
-    protected override void OnBehaviourRemove(IBehaviour behaviour)
-    {
-        behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
-    }
-
-    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
-    {
-        T behaviour = (T)sender;
-        activeBehaviours.Remove(behaviour);
-        AddBehaviour(behaviour);
-    }
-
-    public ActiveBehaviourCollectorSorted()
-    {
-        delegateOnPriorityChanged = OnPriorityChanged;
-    }
-
-    public ActiveBehaviourCollectorSorted(IUniverse universe, Comparison<T> sortBy) : base(universe)
-    {
-        delegateOnPriorityChanged = OnPriorityChanged;
-
-        SortBy = Comparer<T>.Create(sortBy);
-    }
-}

Engine.Core/BaseEntity.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public abstract class BaseEntity : IEntity
 {

Engine.Core/Behaviour.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public abstract class Behaviour : BehaviourBase
 {

Engine.Core/Behaviour2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public abstract class Behaviour2D : Behaviour, IBehaviour2D
 {

Engine.Core/BehaviourBase.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 [System.Diagnostics.DebuggerDisplay("{GetType().Name, nq}, Priority: {Priority}, Initialized: {Initialized}")]
 public abstract class BehaviourBase : BaseEntity, IBehaviour
@@ -44,6 +44,7 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
         _behaviourController = behaviourController;
         OnAssign(behaviourController);
         behaviourController.OnUniverseObjectAssigned.AddListener(delegateOnUniverseObjectAssigned);
+        behaviourController.StateEnable.OnEnabledChanged.AddListener(delegateOnStateEnabledChanged);
         if (behaviourController.UniverseObject is not null)
             OnUniverseObjectAssigned(behaviourController);
         OnBehaviourControllerAssigned?.Invoke(this);
@@ -68,6 +69,7 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
         BehaviourController.UniverseObject.OnActiveChanged.RemoveListener(delegateOnUniverseObjectActiveChanged);
         StateEnable.OnEnabledChanged.RemoveListener(delegateOnStateEnabledChanged);
         BehaviourController.OnUniverseObjectAssigned.RemoveListener(delegateOnUniverseObjectAssigned);
+        BehaviourController.StateEnable.OnEnabledChanged.RemoveListener(delegateOnStateEnabledChanged);
         base.UnassignInternal();
         _behaviourController = null!;
     }
@@ -76,6 +78,8 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
     {
         Debug.Assert.AssertBehaviourControllerAssigned(this);
         Debug.Assert.AssertStateEnableAssigned(this);
+
+        UpdateActive();
     }
 
     private void OnStateEnabledChanged(IStateEnable sender, IStateEnable.EnabledChangedArguments args) => UpdateActive();
@@ -84,7 +88,7 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
     private void UpdateActive()
     {
         bool previousActive = IsActive;
-        _isActive = StateEnable.Enabled && _behaviourController.UniverseObject.IsActive;
+        _isActive = StateEnable.Enabled && _behaviourController.StateEnable.Enabled && _behaviourController.UniverseObject.IsActive;
 
         if (previousActive != IsActive)
             OnActiveChanged?.Invoke(this, new(previousActive));

Engine.Core/BehaviourCollectorSorted.cs

@@ -1,67 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace Syntriax.Engine.Core;
-
-public class BehaviourCollectorSorted<T> : BehaviourCollector<T> where T : class
-{
-    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
-
-    private IComparer<T>? _sortBy = null;
-    public IComparer<T>? SortBy
-    {
-        get => _sortBy;
-        set
-        {
-            _sortBy = value;
-
-            if (value is not null)
-                behaviours.Sort(value);
-        }
-    }
-
-    protected override void AddBehaviour(T behaviour)
-    {
-        if (SortBy is null)
-        {
-            behaviours.Add(behaviour);
-            return;
-        }
-
-        int insertionIndex = behaviours.BinarySearch(behaviour, SortBy);
-
-        if (insertionIndex < 0)
-            insertionIndex = ~insertionIndex;
-
-        behaviours.Insert(insertionIndex, behaviour);
-    }
-
-    protected override void OnBehaviourAdd(IBehaviour behaviour)
-    {
-        behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
-    }
-
-    protected override void OnBehaviourRemove(IBehaviour behaviour)
-    {
-        behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
-    }
-
-    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
-    {
-        T behaviour = (T)sender;
-        behaviours.Remove(behaviour);
-        AddBehaviour(behaviour);
-    }
-
-    public BehaviourCollectorSorted()
-    {
-        delegateOnPriorityChanged = OnPriorityChanged;
-    }
-
-    public BehaviourCollectorSorted(IUniverse universe, Comparison<T> sortBy) : base(universe)
-    {
-        delegateOnPriorityChanged = OnPriorityChanged;
-
-        SortBy = Comparer<T>.Create(sortBy);
-    }
-}

Engine.Core/BehaviourController.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 [System.Diagnostics.DebuggerDisplay("Behaviour Count: {behaviours.Count}")]
 public class BehaviourController : BaseEntity, IBehaviourController
@@ -10,7 +10,7 @@ public class BehaviourController : BaseEntity, IBehaviourController
     public Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments> OnBehaviourRemoved { get; } = new();
     public Event<IHasUniverseObject> OnUniverseObjectAssigned { get; } = new();
 
-    private readonly List<IBehaviour> behaviours = new(Constants.BEHAVIOURS_SIZE_INITIAL);
+    private readonly FastList<IBehaviour> behaviours = new(Constants.BEHAVIOURS_SIZE_INITIAL);
 
     private IUniverseObject _universeObject = null!;
 
@@ -72,7 +72,7 @@ public class BehaviourController : BaseEntity, IBehaviourController
 
     public void RemoveBehaviour<T>(bool removeAll = false) where T : class, IBehaviour
     {
-        for (int i = behaviours.Count; i >= 0; i--)
+        for (int i = behaviours.Count - 1; i >= 0; i--)
         {
             if (behaviours[i] is not T behaviour)
                 continue;

Engine.Core/Collectors/ActiveBehaviourCollector.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace Engine.Core;
+
+public class ActiveBehaviourCollector<T> : ActiveBehaviourCollectorBase<T> where T : class, IBehaviour
+{
+    protected readonly FastList<T> activeBehaviours = new(32);
+    public override T this[Index index] => activeBehaviours[index];
+    public override int Count => activeBehaviours.Count;
+
+    public ActiveBehaviourCollector() { }
+    public ActiveBehaviourCollector(IUniverse universe) : base(universe) { }
+
+    protected override void AddBehaviour(T behaviour) => activeBehaviours.Add(behaviour);
+    protected override bool RemoveBehaviour(T tBehaviour) => activeBehaviours.Remove(tBehaviour);
+}

Engine.Core/Collectors/ActiveBehaviourCollectorBase.cs

@@ -1,14 +1,12 @@
 using System;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
-public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : class, IBehaviour
+public abstract class ActiveBehaviourCollectorBase<T> : IBehaviourCollector<T> where T : class, IBehaviour
 {
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
+    protected readonly Dictionary<IActive, T> monitoringActiveToBehaviour = new(32);
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
+    protected readonly FastList<T> monitoringBehaviours = new(32);
-    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
-    public Event<IAssignable>? OnUnassigned { get; } = new();
 
     private readonly Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments>.EventHandler delegateOnBehaviourAdded = null!;
     private readonly Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments>.EventHandler delegateOnBehaviourRemoved = null!;
@@ -16,80 +14,16 @@ public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : clas
     private readonly Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments>.EventHandler delegateOnUniverseObjectRegistered = null!;
     private readonly Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments>.EventHandler delegateOnUniverseObjectUnregistered = null!;
 
-    private readonly List<T> monitoringBehaviours = new(32);
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
-    protected readonly List<T> activeBehaviours = new(32);
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
-    protected readonly Dictionary<IActive, T> monitoringActiveToBehaviour = new(32);
+    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
+    public Event<IAssignable>? OnUnassigned { get; } = new();
 
+    public abstract int Count { get; }
+
+    public abstract T this[Index index] { get; }
     public IUniverse Universe { get; private set; } = null!;
 
-    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
-    {
-        IUniverseObject universeObject = args.UniverseObjectRegistered;
-
-        universeObject.BehaviourController.OnBehaviourAdded.AddListener(delegateOnBehaviourAdded);
-        universeObject.BehaviourController.OnBehaviourRemoved.AddListener(delegateOnBehaviourRemoved);
-
-        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
-            OnBehaviourAdded(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
-    }
-
-    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
-    {
-        IUniverseObject universeObject = args.UniverseObjectUnregistered;
-
-        universeObject.BehaviourController.OnBehaviourAdded.RemoveListener(delegateOnBehaviourAdded);
-        universeObject.BehaviourController.OnBehaviourRemoved.RemoveListener(delegateOnBehaviourRemoved);
-
-        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
-            OnBehaviourRemoved(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
-    }
-
-    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
-    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
-    {
-        if (args.BehaviourAdded is not T tBehaviour)
-            return;
-
-        monitoringBehaviours.Add(tBehaviour);
-        monitoringActiveToBehaviour.Add(tBehaviour, tBehaviour);
-        tBehaviour.OnActiveChanged.AddListener(delegateOnBehaviourStateChanged);
-        OnBehaviourStateChanged(tBehaviour, new(!tBehaviour.IsActive));
-    }
-
-    protected virtual void AddBehaviour(T behaviour) => activeBehaviours.Add(behaviour);
-    private void OnBehaviourStateChanged(IActive sender, IActive.ActiveChangedArguments args)
-    {
-        T behaviour = monitoringActiveToBehaviour[sender];
-        if (sender.IsActive)
-        {
-            AddBehaviour(behaviour);
-            OnBehaviourAdd(behaviour);
-            OnCollected?.Invoke(this, new(behaviour));
-        }
-        else if (activeBehaviours.Remove(behaviour))
-        {
-            OnBehaviourRemove(behaviour);
-            OnRemoved?.Invoke(this, new(behaviour));
-        }
-    }
-
-    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
-    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
-    {
-        if (args.BehaviourRemoved is not T tBehaviour)
-            return;
-
-        if (!monitoringBehaviours.Remove(tBehaviour) || !monitoringActiveToBehaviour.Remove(tBehaviour))
-            return;
-
-        tBehaviour.OnActiveChanged.RemoveListener(delegateOnBehaviourStateChanged);
-        if (activeBehaviours.Remove(tBehaviour))
-        {
-            OnBehaviourRemove(tBehaviour);
-            OnRemoved?.Invoke(this, new(tBehaviour));
-        }
-    }
-
     public bool Assign(IUniverse universe)
     {
         if (Universe is not null)
@@ -123,10 +57,75 @@ public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : clas
         return true;
     }
 
-    public int Count => activeBehaviours.Count;
+    protected abstract void AddBehaviour(T behaviour);
-    public T this[Index index] => activeBehaviours[index];
+    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
+    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
+    {
+        if (args.BehaviourAdded is not T tBehaviour)
+            return;
 
-    public ActiveBehaviourCollector()
+        monitoringBehaviours.Add(tBehaviour);
+        monitoringActiveToBehaviour.Add(tBehaviour, tBehaviour);
+        tBehaviour.OnActiveChanged.AddListener(delegateOnBehaviourStateChanged);
+        OnBehaviourStateChanged(tBehaviour, new(!tBehaviour.IsActive));
+    }
+
+    protected abstract bool RemoveBehaviour(T behaviour);
+    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
+    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
+    {
+        if (args.BehaviourRemoved is not T tBehaviour)
+            return;
+
+        if (!monitoringBehaviours.Remove(tBehaviour) || !monitoringActiveToBehaviour.Remove(tBehaviour))
+            return;
+
+        tBehaviour.OnActiveChanged.RemoveListener(delegateOnBehaviourStateChanged);
+        if (!RemoveBehaviour(tBehaviour))
+            return;
+
+        OnBehaviourRemove(tBehaviour);
+        OnRemoved?.Invoke(this, new(tBehaviour));
+    }
+    private void OnBehaviourStateChanged(IActive sender, IActive.ActiveChangedArguments args)
+    {
+        T behaviour = monitoringActiveToBehaviour[sender];
+        if (sender.IsActive)
+        {
+            AddBehaviour(behaviour);
+            OnBehaviourAdd(behaviour);
+            OnCollected?.Invoke(this, new(behaviour));
+        }
+        else if (RemoveBehaviour(behaviour))
+        {
+            OnBehaviourRemove(behaviour);
+            OnRemoved?.Invoke(this, new(behaviour));
+        }
+    }
+
+    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
+    {
+        IUniverseObject universeObject = args.UniverseObjectRegistered;
+
+        universeObject.BehaviourController.OnBehaviourAdded.AddListener(delegateOnBehaviourAdded);
+        universeObject.BehaviourController.OnBehaviourRemoved.AddListener(delegateOnBehaviourRemoved);
+
+        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
+            OnBehaviourAdded(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
+    }
+
+    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
+    {
+        IUniverseObject universeObject = args.UniverseObjectUnregistered;
+
+        universeObject.BehaviourController.OnBehaviourAdded.RemoveListener(delegateOnBehaviourAdded);
+        universeObject.BehaviourController.OnBehaviourRemoved.RemoveListener(delegateOnBehaviourRemoved);
+
+        for (int i = 0; i < universeObject.BehaviourController.Count; i++)
+            OnBehaviourRemoved(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
+    }
+
+    public ActiveBehaviourCollectorBase()
     {
         delegateOnBehaviourAdded = OnBehaviourAdded;
         delegateOnBehaviourRemoved = OnBehaviourRemoved;
@@ -135,7 +134,7 @@ public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : clas
         delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
     }
 
-    public ActiveBehaviourCollector(IUniverse universe)
+    public ActiveBehaviourCollectorBase(IUniverse universe)
     {
         delegateOnBehaviourAdded = OnBehaviourAdded;
         delegateOnBehaviourRemoved = OnBehaviourRemoved;

Engine.Core/Collectors/ActiveBehaviourCollectorOrdered.cs

@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+public class ActiveBehaviourCollectorOrdered<TIndex, TItem> : ActiveBehaviourCollector<TItem> where TItem : class, IBehaviour where TIndex : IComparable
+{
+    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
+
+    private readonly SortedDictionary<TIndex, FastList<TItem>> behaviours = null!;
+
+    private readonly Func<TItem, TIndex> getIndexFunc = null!;
+    private readonly IComparer<TIndex> sortBy = null!;
+
+    private int count = 0;
+    public override int Count => count;
+
+    public override TItem this[Index index]
+    {
+        get
+        {
+            int actualIndex = index.IsFromEnd
+                ? count - index.Value
+                : index.Value;
+
+            if (actualIndex < 0 || actualIndex >= count)
+                throw new IndexOutOfRangeException();
+
+            int leftIndex = actualIndex;
+            foreach ((TIndex i, FastList<TItem> list) in behaviours)
+            {
+                if (leftIndex < list.Count)
+                    return list[leftIndex];
+                leftIndex -= list.Count;
+            }
+            throw new IndexOutOfRangeException();
+        }
+    }
+
+    protected override bool RemoveBehaviour(TItem tBehaviour)
+    {
+        TIndex index = getIndexFunc(tBehaviour);
+        if (!behaviours.TryGetValue(index, out FastList<TItem>? list))
+            throw new Exceptions.NotFoundException($"Index of '{index}' is not found in the collector");
+
+        if (!list.Remove(tBehaviour))
+            return false;
+
+        count--;
+        return true;
+    }
+
+    protected override void AddBehaviour(TItem behaviour)
+    {
+        TIndex key = getIndexFunc(behaviour);
+        if (!behaviours.TryGetValue(key, out FastList<TItem>? list))
+            behaviours[key] = list = [];
+
+        count++;
+        list.Add(behaviour);
+    }
+
+    protected override void OnBehaviourAdd(IBehaviour behaviour) => behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
+    protected override void OnBehaviourRemove(IBehaviour behaviour) => behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
+
+    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
+    {
+        TItem behaviour = (TItem)sender;
+        RemoveBehaviour(behaviour);
+        AddBehaviour(behaviour);
+    }
+
+    public ActiveBehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = Comparer<TIndex>.Create(sortBy);
+        behaviours = new(this.sortBy);
+    }
+
+    public ActiveBehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy) : base(universe)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = Comparer<TIndex>.Create(sortBy);
+        behaviours = new(this.sortBy);
+    }
+
+    public ActiveBehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy)
+    {
+        this.getIndexFunc = getIndexFunc;
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.sortBy = sortBy;
+        behaviours = new(sortBy);
+    }
+
+    public ActiveBehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy) : base(universe)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = sortBy;
+        behaviours = new(sortBy);
+    }
+}

Engine.Core/Collectors/BehaviourCollector.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace Engine.Core;
+
+public class BehaviourCollector<T> : BehaviourCollectorBase<T> where T : class
+{
+    protected readonly FastList<T> behaviours = new(32);
+
+    public override T this[Index index] => behaviours[index];
+    public override int Count => behaviours.Count;
+
+    protected override void AddBehaviour(T behaviour) => behaviours.Add(behaviour);
+    protected override bool RemoveBehaviour(T tBehaviour) => behaviours.Remove(tBehaviour);
+
+    public BehaviourCollector() { }
+    public BehaviourCollector(IUniverse universe) : base(universe) { }
+}

Engine.Core/Collectors/BehaviourCollectorBase.cs

@@ -1,24 +1,87 @@
 using System;
-using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
-public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
+public abstract class BehaviourCollectorBase<T> : IBehaviourCollector<T> where T : class
 {
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
-    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
-    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
-    public Event<IAssignable>? OnUnassigned { get; } = new();
-
     private readonly Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments>.EventHandler delegateOnBehaviourAdded = null!;
     private readonly Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments>.EventHandler delegateOnBehaviourRemoved = null!;
     private readonly Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments>.EventHandler delegateOnUniverseObjectRegistered = null!;
     private readonly Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments>.EventHandler delegateOnUniverseObjectUnregistered = null!;
 
-    protected readonly List<T> behaviours = new(32);
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourCollectedArguments> OnCollected { get; } = new();
+    public Event<IBehaviourCollector<T>, IBehaviourCollector<T>.BehaviourRemovedArguments> OnRemoved { get; } = new();
+    public Event<IHasUniverse> OnUniverseAssigned { get; } = new();
+    public Event<IAssignable>? OnUnassigned { get; } = new();
 
     public IUniverse Universe { get; private set; } = null!;
 
+    public abstract int Count { get; }
+
+    public abstract T this[Index index] { get; }
+
+    public bool Assign(IUniverse universe)
+    {
+        if (Universe is not null)
+            return false;
+
+        foreach (IUniverseObject universeObject in universe.UniverseObjects)
+            OnUniverseObjectRegistered(universe, new(universeObject));
+
+        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
+        universe.OnPreUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
+
+        Universe = universe;
+        OnAssign(universe);
+        OnUniverseAssigned?.Invoke(this);
+
+        return true;
+    }
+
+    public bool Unassign()
+    {
+        if (Universe is null)
+            return false;
+
+        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
+            OnUniverseObjectUnregistered(Universe, new(universeObject));
+
+        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
+        Universe.OnPreUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
+
+        Universe = null!;
+        OnUnassigned?.Invoke(this);
+        return true;
+    }
+
+    protected virtual void OnAssign(IUniverse universe) { }
+
+    protected abstract void AddBehaviour(T behaviour);
+    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
+    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
+    {
+        if (args.BehaviourAdded is not T tBehaviour)
+            return;
+
+        AddBehaviour(tBehaviour);
+        OnBehaviourAdd(args.BehaviourAdded);
+        OnCollected?.Invoke(this, new(tBehaviour));
+    }
+
+    protected abstract bool RemoveBehaviour(T tBehaviour);
+    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
+    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
+    {
+        if (args.BehaviourRemoved is not T tBehaviour)
+            return;
+
+        if (!RemoveBehaviour(tBehaviour))
+            return;
+
+        OnBehaviourRemove(args.BehaviourRemoved);
+        OnRemoved?.Invoke(this, new(tBehaviour));
+    }
+
     private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
     {
         IUniverseObject universeObject = args.UniverseObjectRegistered;
@@ -41,70 +104,7 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
             OnBehaviourRemoved(universeObject.BehaviourController, new(universeObject.BehaviourController[i]));
     }
 
-    protected virtual void AddBehaviour(T behaviour) => behaviours.Add(behaviour);
+    public BehaviourCollectorBase()
-    protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
-    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
-    {
-        if (args.BehaviourAdded is not T tBehaviour)
-            return;
-
-        AddBehaviour(tBehaviour);
-        OnBehaviourAdd(args.BehaviourAdded);
-        OnCollected?.Invoke(this, new(tBehaviour));
-    }
-
-    protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
-    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
-    {
-        if (args.BehaviourRemoved is not T tBehaviour)
-            return;
-
-        if (!behaviours.Remove(tBehaviour))
-            return;
-
-        OnBehaviourRemove(args.BehaviourRemoved);
-        OnRemoved?.Invoke(this, new(tBehaviour));
-    }
-
-    protected virtual void OnAssign(IUniverse universe) { }
-    public bool Assign(IUniverse universe)
-    {
-        if (Universe is not null)
-            return false;
-
-        foreach (IUniverseObject universeObject in universe.UniverseObjects)
-            OnUniverseObjectRegistered(universe, new(universeObject));
-
-        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
-        universe.OnUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
-
-        Universe = universe;
-        OnAssign(universe);
-        OnUniverseAssigned?.Invoke(this);
-
-        return true;
-    }
-
-    public bool Unassign()
-    {
-        if (Universe is null)
-            return false;
-
-        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
-            OnUniverseObjectUnregistered(Universe, new(universeObject));
-
-        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
-        Universe.OnUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
-
-        Universe = null!;
-        OnUnassigned?.Invoke(this);
-        return true;
-    }
-
-    public int Count => behaviours.Count;
-    public T this[Index index] => behaviours[index];
-
-    public BehaviourCollector()
     {
         delegateOnBehaviourAdded = OnBehaviourAdded;
         delegateOnBehaviourRemoved = OnBehaviourRemoved;
@@ -112,7 +112,7 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
         delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
     }
 
-    public BehaviourCollector(IUniverse universe)
+    public BehaviourCollectorBase(IUniverse universe)
     {
         delegateOnBehaviourAdded = OnBehaviourAdded;
         delegateOnBehaviourRemoved = OnBehaviourRemoved;

Engine.Core/Collectors/BehaviourCollectorOrdered.cs

@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+public class BehaviourCollectorOrdered<TIndex, TItem> : BehaviourCollectorBase<TItem> where TItem : class where TIndex : IComparable
+{
+    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
+
+    private readonly SortedDictionary<TIndex, FastList<TItem>> behaviours = null!;
+
+    private readonly Func<TItem, TIndex> getIndexFunc = null!;
+    private readonly IComparer<TIndex> sortBy = null!;
+
+    private int count = 0;
+    public override int Count => count;
+
+    public override TItem this[Index index]
+    {
+        get
+        {
+            int actualIndex = index.IsFromEnd
+                ? count - index.Value
+                : index.Value;
+
+            if (actualIndex < 0 || actualIndex >= count)
+                throw new IndexOutOfRangeException();
+
+            int leftIndex = actualIndex;
+            foreach ((TIndex i, FastList<TItem> list) in behaviours)
+            {
+                if (leftIndex < list.Count)
+                    return list[leftIndex];
+                leftIndex -= list.Count;
+            }
+            throw new IndexOutOfRangeException();
+        }
+    }
+
+    protected override bool RemoveBehaviour(TItem tBehaviour)
+    {
+        TIndex index = getIndexFunc(tBehaviour);
+        if (!behaviours.TryGetValue(index, out FastList<TItem>? list))
+            throw new Exceptions.NotFoundException($"Index of '{index}' is not found in the collector");
+
+        if (!list.Remove(tBehaviour))
+            return false;
+
+        count--;
+        return true;
+    }
+
+    protected override void AddBehaviour(TItem behaviour)
+    {
+        TIndex key = getIndexFunc(behaviour);
+        if (!behaviours.TryGetValue(key, out FastList<TItem>? list))
+            behaviours[key] = list = [];
+
+        count++;
+        list.Add(behaviour);
+    }
+
+    protected override void OnBehaviourAdd(IBehaviour behaviour) => behaviour.OnPriorityChanged.AddListener(delegateOnPriorityChanged);
+    protected override void OnBehaviourRemove(IBehaviour behaviour) => behaviour.OnPriorityChanged.RemoveListener(delegateOnPriorityChanged);
+
+    private void OnPriorityChanged(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
+    {
+        TItem behaviour = (TItem)sender;
+        RemoveBehaviour(behaviour);
+        AddBehaviour(behaviour);
+    }
+
+    public BehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = Comparer<TIndex>.Create(sortBy);
+        behaviours = new(this.sortBy);
+    }
+
+    public BehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy) : base(universe)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = Comparer<TIndex>.Create(sortBy);
+        behaviours = new(this.sortBy);
+    }
+
+    public BehaviourCollectorOrdered(Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy)
+    {
+        this.getIndexFunc = getIndexFunc;
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.sortBy = sortBy;
+        behaviours = new(sortBy);
+    }
+
+    public BehaviourCollectorOrdered(IUniverse universe, Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy) : base(universe)
+    {
+        delegateOnPriorityChanged = OnPriorityChanged;
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = sortBy;
+        behaviours = new(sortBy);
+    }
+}

Engine.Core/CoroutineManager.cs

@@ -1,7 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public class CoroutineManager : Behaviour, IUpdate
 {

Engine.Core/CoroutineYield.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public class CoroutineYield(Func<bool> condition) : ICoroutineYield
 {

Engine.Core/Debug/AssertHelpers.cs

@@ -1,6 +1,6 @@
 using System.Runtime.CompilerServices;
 
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public static class Assert
 {
@@ -10,21 +10,21 @@ public static class Assert
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static void AssertBehaviourControllerAssigned(IHasBehaviourController assignable)
-        => System.Diagnostics.Debug.Assert(assignable.BehaviourController is not null, $"{assignable.GetType().Name} must be initialized");
+        => System.Diagnostics.Debug.Assert(assignable.BehaviourController is not null, $"{assignable.GetType().Name} must be assigned an {nameof(IBehaviourController)}");
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static void AssertEntityAssigned(IHasEntity assignable)
-        => System.Diagnostics.Debug.Assert(assignable.Entity is not null, $"{assignable.GetType().Name} must be initialized");
+        => System.Diagnostics.Debug.Assert(assignable.Entity is not null, $"{assignable.GetType().Name} must be assigned an {nameof(IEntity)}");
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static void AssertUniverseAssigned(IHasUniverse assignable)
-        => System.Diagnostics.Debug.Assert(assignable.Universe is not null, $"{assignable.GetType().Name} must be initialized");
+        => System.Diagnostics.Debug.Assert(assignable.Universe is not null, $"{assignable.GetType().Name} must be assigned an {nameof(IUniverse)}");
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static void AssertUniverseObjectAssigned(IHasUniverseObject assignable)
-        => System.Diagnostics.Debug.Assert(assignable.UniverseObject is not null, $"{assignable.GetType().Name} must be initialized");
+        => System.Diagnostics.Debug.Assert(assignable.UniverseObject is not null, $"{assignable.GetType().Name} must be assigned an {nameof(IUniverseObject)}");
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static void AssertStateEnableAssigned(IHasStateEnable assignable)
-        => System.Diagnostics.Debug.Assert(assignable.StateEnable is not null, $"{assignable.GetType().Name} must be initialized");
+        => System.Diagnostics.Debug.Assert(assignable.StateEnable is not null, $"{assignable.GetType().Name} must be assigned an {nameof(IStateEnable)}");
 }

Engine.Core/Debug/ConsoleLogger.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public class ConsoleLogger : LoggerBase
 {

Engine.Core/Debug/FileLogger.cs

@@ -1,7 +1,7 @@
 using System;
 using System.IO;
 
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public class FileLogger : LoggerBase
 {
@@ -14,6 +14,9 @@ public class FileLogger : LoggerBase
 
     public FileLogger(string filePath)
     {
+        if (!filePath.EndsWith(".log"))
+            filePath += ".log";
+
         FilePath = filePath;
 
         bool isRelativePath = Path.GetFullPath(filePath).CompareTo(filePath) != 0;

Engine.Core/Debug/ILogger.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public interface ILogger
 {

Engine.Core/Debug/LoggerBase.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public abstract class LoggerBase : ILogger
 {

Engine.Core/Debug/LoggerContainer.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public class LoggerContainer : Behaviour, ILogger
 {

Engine.Core/Debug/LoggerExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Diagnostics;
 
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public static class LoggerExtensions
 {
@@ -29,7 +29,7 @@ public static class LoggerExtensions
         Log(logger, caller, $"{nameof(StackTrace)}:{Environment.NewLine}{exception.StackTrace}", ILogger.Level.Trace);
     }
 
-    public static void LogTrace<T>(this ILogger logger, T caller, StackTrace stackTrace, bool force = false)
+    public static void LogTrace<T>(this ILogger logger, T caller, StackTrace? stackTrace = null, bool force = false)
     {
         Log(logger, caller, $"{nameof(StackTrace)}:{Environment.NewLine}{stackTrace ?? new()}", ILogger.Level.Trace, force);
     }

Engine.Core/Debug/LoggerWrapper.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public class LoggerWrapper(ILogger firstLogger, ILogger secondLogger) : ILogger
 {

Engine.Core/Debug/LoggerWrapperExtensions.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Debug;
+namespace Engine.Core.Debug;
 
 public static class LoggerWrapperExtensions
 {

Engine.Core/Debug/RotatingFileLogger.cs

@@ -0,0 +1,71 @@
+using System;
+using System.IO;
+using System.Linq;
+
+namespace Engine.Core.Debug;
+
+public class RotatingFileLogger : ILogger
+{
+    public readonly FileLogger FileLogger = null!;
+    public readonly string Directory = string.Empty;
+    public readonly int RotateLength = 3;
+
+    public RotatingFileLogger(string directory, string namePrefix, string nameSuffix = "", int rotateLength = 3)
+    {
+        RotateLength = rotateLength;
+
+        string fileName = Path.Combine(directory, namePrefix);
+        if (!string.IsNullOrWhiteSpace(nameSuffix))
+            fileName += $"_{nameSuffix}";
+
+        bool isRelativePath = Path.GetFullPath(fileName).CompareTo(fileName) != 0;
+
+        if (isRelativePath)
+            fileName = Path.GetFullPath(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, fileName));
+
+        if (File.Exists($"{fileName}.log"))
+            RenameExistingLogs(fileName, RotateLength);
+
+        FileLogger = new(fileName);
+
+        Directory = Path.GetDirectoryName(fileName) ?? throw new("Unexpected error on getting directory of logger path");
+        RotateLastLogs(Directory, namePrefix, RotateLength);
+    }
+
+    private static void RenameExistingLogs(string filePath, int rotateLength)
+    {
+        for (int i = rotateLength - 1; i >= 0; i--)
+        {
+            string source = i == 0
+                ? $"{filePath}.log"
+                : $"{filePath}_{i}.log";
+
+            string dest = $"{filePath}_{i + 1}.log";
+
+            if (!File.Exists(source))
+                continue;
+
+            if (File.Exists(dest))
+                File.Delete(dest);
+
+            File.Move(source, dest);
+        }
+    }
+
+    private static void RotateLastLogs(string directory, string prefix, int rotateLength)
+    {
+        IOrderedEnumerable<string> logs = System.IO.Directory.GetFiles(directory, $"{prefix}*.log")
+            .OrderBy(File.GetCreationTime);
+
+        foreach (string file in logs.Skip(rotateLength))
+            try
+            {
+                ILogger.Shared.Log($"Removing log file located at \"{file}\" during rotation.");
+                File.Delete(file);
+            }
+            catch (Exception e) { ILogger.Shared.LogException($"Failed to rotate log file at \"{file}\"", e); }
+    }
+
+    public ILogger.Level FilterLevel { get => FileLogger.FilterLevel; set => FileLogger.FilterLevel = value; }
+    public void Log(string message, ILogger.Level level = ILogger.Level.Info, bool force = false) => FileLogger.Log(message, level, force);
+}

Engine.Core/Engine.Core.csproj

@@ -4,7 +4,8 @@
     <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>false</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <RootNamespace>Syntriax.Engine.Core</RootNamespace>
+    <RootNamespace>Engine.Core</RootNamespace>
+    <AssemblyName>Engine.Core</AssemblyName>
   </PropertyGroup>
 
 </Project>

Engine.Core/Exceptions/AssignFailedException.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Exceptions;
+namespace Engine.Core.Exceptions;
 
 public class AssignFailedException(string? message) : Exception(message)
 {

Engine.Core/Exceptions/BehaviourNotFoundException.cs

@@ -1,3 +1,3 @@
-namespace Syntriax.Engine.Core.Exceptions;
+namespace Engine.Core.Exceptions;
 
 public class BehaviourNotFoundException(string? message) : NotFoundException(message);

Engine.Core/Exceptions/NotAssignedException.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Exceptions;
+namespace Engine.Core.Exceptions;
 
 public class NotAssignedException(string? message) : Exception(message)
 {

Engine.Core/Exceptions/NotFoundException.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Exceptions;
+namespace Engine.Core.Exceptions;
 
 public class NotFoundException(string? message) : Exception(message)
 {

Engine.Core/Exceptions/UniverseObjectNotFoundException.cs

@@ -1,3 +1,3 @@
-namespace Syntriax.Engine.Core.Exceptions;
+namespace Engine.Core.Exceptions;
 
 public class UniverseObjectNotFoundException(string? message) : NotFoundException(message);

Engine.Core/Extensions/BehaviourControllerExtensions.cs

@@ -1,9 +1,9 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class BehaviourControllerExtensions
 {
@@ -27,7 +27,7 @@ public static class BehaviourControllerExtensions
     /// <param name="behaviourController">The <see cref="IBehaviourController"/> to start searching from.</param>
     /// <returns>The <see cref="IBehaviour"/> of the specified type if found; otherwise, throws <see cref="BehaviourNotFoundException"/>.</returns>
     public static T GetRequiredBehaviour<T>(this IBehaviourController behaviourController) where T : class
-        => behaviourController.GetBehaviour<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject.Name}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName}");
+        => behaviourController.GetBehaviour<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject?.Name ?? "NULL"}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName}");
 
     /// <summary>
     /// Gets an existing <see cref="IBehaviour"/> of the specified type, or adds and returns a new one if it doesn't exist.
@@ -93,7 +93,7 @@ public static class BehaviourControllerExtensions
     /// <param name="behaviourController">The <see cref="IBehaviourController"/> to start searching from.</param>
     /// <returns>The <see cref="IBehaviour"/> of the specified type if found; otherwise, throws <see cref="BehaviourNotFoundException"/>.</returns>
     public static T GetRequiredBehaviourInParent<T>(this IBehaviourController behaviourController) where T : class
-        => behaviourController.GetBehaviourInParent<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject.Name}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName} on any parent");
+        => behaviourController.GetBehaviourInParent<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject?.Name ?? "NULL"}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName} on any parent");
 
     /// <summary>
     /// Gets all <see cref="IBehaviour"/>s of the specified type in it's <see cref="IUniverseObject"/>'s parents recursively and stores them in the provided list.
@@ -140,7 +140,7 @@ public static class BehaviourControllerExtensions
         if (behaviourController.GetBehaviour<T>() is T localBehaviour)
             return localBehaviour;
 
-        foreach (IUniverseObject child in behaviourController.UniverseObject)
+        foreach (IUniverseObject child in behaviourController.UniverseObject.Children)
             if (GetBehaviourInChildren<T>(child.BehaviourController) is T behaviour)
                 return behaviour;
 
@@ -154,7 +154,7 @@ public static class BehaviourControllerExtensions
     /// <param name="behaviourController">The <see cref="IBehaviourController"/> to start searching from.</param>
     /// <returns>The <see cref="IBehaviour"/> of the specified type if found; otherwise, throws <see cref="BehaviourNotFoundException"/>.</returns>
     public static T GetRequiredBehaviourInChildren<T>(this IBehaviourController behaviourController) where T : class
-        => behaviourController.GetBehaviourInChildren<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject.Name}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName} on any children ");
+        => behaviourController.GetBehaviourInChildren<T>() ?? throw new BehaviourNotFoundException($"{behaviourController.UniverseObject?.Name ?? "NULL"}'s {nameof(IBehaviourController)} does not contain any {typeof(T).FullName} on any children ");
 
     /// <summary>
     /// Gets all <see cref="IBehaviour"/>s of the specified type in it's <see cref="IUniverseObject"/>'s children recursively and stores them in the provided list.
@@ -176,7 +176,7 @@ public static class BehaviourControllerExtensions
         foreach (T behaviour in cache)
             behaviours.Add(behaviour);
 
-        foreach (IUniverseObject child in universeObject)
+        foreach (IUniverseObject child in universeObject.Children)
             TraverseChildrenForBehaviour(child, behaviours, cache);
     }
 }

Engine.Core/Extensions/EnumExtensions.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class EnumExtensions
 {

Engine.Core/Extensions/FloatExtensions.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class FloatExtensions
 {

Engine.Core/Extensions/TransformExtensions.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class TransformExtensions
 {

Engine.Core/Extensions/UniverseExtensions.cs

@@ -1,6 +1,6 @@
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class UniverseExtensions
 {

Engine.Core/Extensions/UniverseObjectExtensions.cs

@@ -1,9 +1,9 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class UniverseObjectExtensions
 {
@@ -12,7 +12,7 @@ public static class UniverseObjectExtensions
         if (!string.IsNullOrWhiteSpace(name))
             universeObject.Name = name;
         if (parent is not null)
-            universeObject.SetParent(parent);
+            universeObject.Parent = parent;
         return universeObject;
     }
 
@@ -81,7 +81,7 @@ public static class UniverseObjectExtensions
     /// <returns>The <see cref="IUniverseObject"/> of the specified type if found; otherwise, null.</returns>
     public static T? GetUniverseObjectInParent<T>(this IUniverseObject universeObject) where T : class
     {
-        if (universeObject.GetUniverseObject<T>() is T localUniverseObject)
+        if (universeObject.Children.GetUniverseObject<T>() is T localUniverseObject)
             return localUniverseObject;
 
         IUniverseObject? parent = universeObject;
@@ -129,10 +129,10 @@ public static class UniverseObjectExtensions
     /// <returns>The <see cref="IUniverseObject"/> of the specified type if found; otherwise, null.</returns>
     public static T? GetUniverseObjectInChildren<T>(this IUniverseObject universeObject) where T : class
     {
-        if (universeObject.GetUniverseObject<T>() is T localUniverseObject)
+        if (universeObject.Children.GetUniverseObject<T>() is T localUniverseObject)
             return localUniverseObject;
 
-        foreach (IUniverseObject child in universeObject)
+        foreach (IUniverseObject child in universeObject.Children)
             if (GetUniverseObjectInChildren<T>(child) is T behaviour)
                 return behaviour;
 
@@ -246,7 +246,7 @@ public static class UniverseObjectExtensions
 
         foreach (IUniverseObject universeObject in universeObjects)
         {
-            universeObject.Find(cache);
+            universeObject.Children.Find(cache);
             foreach (T behaviour in cache)
                 instances.Add(behaviour);
         }

Engine.Core/Factory/Abstract/IFactory.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Factory.Abstract;
+namespace Engine.Core.Factory.Abstract;
 
 public interface IFactory<TInterface> where TInterface : class
 {

Engine.Core/Factory/BehaviourControllerFactory.cs

@@ -1,13 +1,13 @@
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public class BehaviourControllerFactory
 {
-    public static IBehaviourController Instantiate(IUniverseObject universeObject)
+    public static IBehaviourController Instantiate(IUniverseObject universeObject, IStateEnable? stateEnable = null)
-        => Instantiate<BehaviourController>(universeObject);
+        => Instantiate<BehaviourController>(universeObject, stateEnable);
 
-    public static T Instantiate<T>(IUniverseObject universeObject, params object?[]? args)
+    public static T Instantiate<T>(IUniverseObject universeObject, IStateEnable? stateEnable = null, params object?[]? args)
         where T : class, IBehaviourController
     {
         T behaviourController = TypeFactory.Get<T>(args);
@@ -18,6 +18,17 @@ public class BehaviourControllerFactory
         if (!behaviourController.Assign(universeObject))
             throw AssignFailedException.From(behaviourController, universeObject);
 
+        if (stateEnable is not null)
+        {
+            if (!stateEnable.Assign(behaviourController))
+                throw AssignFailedException.From(stateEnable, behaviourController);
+
+            if (!behaviourController.Assign(stateEnable))
+                throw AssignFailedException.From(behaviourController, stateEnable);
+        }
+        else
+            StateEnableFactory.Instantiate(behaviourController);
+
         return behaviourController;
     }
 }

Engine.Core/Factory/BehaviourFactory.cs

@@ -1,6 +1,6 @@
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public class BehaviourFactory
 {
@@ -12,12 +12,15 @@ public class BehaviourFactory
     {
         T behaviour = TypeFactory.Get<T>(args);
 
-        stateEnable ??= TypeFactory.Get<StateEnable>();
+        if (stateEnable is not null)
+        {
             if (!stateEnable.Assign(behaviour))
                 throw AssignFailedException.From(stateEnable, behaviour);
-
             if (!behaviour.Assign(stateEnable))
                 throw AssignFailedException.From(behaviour, stateEnable);
+        }
+        else
+            StateEnableFactory.Instantiate(behaviour);
 
         return behaviour;
     }

Engine.Core/Factory/FactoryBase.cs

@@ -1,7 +1,7 @@
 using System;
-using Syntriax.Engine.Core.Factory.Abstract;
+using Engine.Core.Factory.Abstract;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public abstract class FactoryBase<TInterface> : IFactory<TInterface>
     where TInterface : class

Engine.Core/Factory/StateEnableFactory.cs

@@ -1,6 +1,6 @@
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public class StateEnableFactory
 {

Engine.Core/Factory/TransformFactory.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public class TransformFactory
 {

Engine.Core/Factory/TypeFactory.cs

@@ -3,7 +3,7 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public static class TypeFactory
 {

Engine.Core/Factory/UniverseObjectFactory.cs

@@ -1,6 +1,6 @@
-using Syntriax.Engine.Core.Exceptions;
+using Engine.Core.Exceptions;
 
-namespace Syntriax.Engine.Core.Factory;
+namespace Engine.Core.Factory;
 
 public class UniverseObjectFactory
 {
@@ -18,18 +18,25 @@ public class UniverseObjectFactory
     {
         T universeObject = TypeFactory.Get<T>(args);
 
-        behaviourController ??= TypeFactory.Get<BehaviourController>();
+        if (behaviourController is not null)
-        stateEnable ??= TypeFactory.Get<StateEnable>();
+        {
-
             if (!behaviourController.Assign(universeObject))
                 throw AssignFailedException.From(behaviourController, universeObject);
-        if (!stateEnable.Assign(universeObject))
-            throw AssignFailedException.From(stateEnable, universeObject);
-
             if (!universeObject.Assign(behaviourController))
                 throw AssignFailedException.From(universeObject, behaviourController);
+        }
+        else
+            BehaviourControllerFactory.Instantiate(universeObject);
+
+        if (stateEnable is not null)
+        {
+            if (!stateEnable.Assign(universeObject))
+                throw AssignFailedException.From(stateEnable, universeObject);
             if (!universeObject.Assign(stateEnable))
                 throw AssignFailedException.From(universeObject, stateEnable);
+        }
+        else
+            StateEnableFactory.Instantiate(universeObject);
 
         return universeObject;
     }

Engine.Core/Helpers/Event.cs

@@ -1,9 +1,15 @@
 using System;
 using System.Collections.Generic;
 
-using Syntriax.Engine.Core.Debug;
+using Engine.Core.Debug;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
+
+// TODO!: every reverse loop has a chance to have more than 1 unsubscription,
+// for (int i = listeners.Count - 1; i >= 0; i--) 
+// can be replaced with 
+// for (int i = listeners.Count - 1; i >= 0; i = Math.Min(i - 1, listeners.Count - 1))
+// but this would causes possible double calls on already called callbacks, find a better method.
 
 /// <summary>
 /// Represents a simple event with no parameters.

Engine.Core/Helpers/FastList.cs

@@ -0,0 +1,102 @@
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+public class FastList<T> : IList<T>, IReadOnlyList<T>, IEnumerable<T> where T : notnull
+{
+    private readonly List<T> items = [];
+    private readonly Dictionary<T, int> indexMap = [];
+
+    public bool IsReadOnly { get; set; } = false;
+    public int Count => items.Count;
+    public T this[int index]
+    {
+        get => items[index];
+        set
+        {
+            if (IsReadOnly)
+                throw new System.Data.ReadOnlyException();
+
+            items[index] = value;
+        }
+    }
+
+    public void Add(T item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        indexMap[item] = items.Count;
+        items.Add(item);
+    }
+
+    public void RemoveAt(int i) => Remove(items[i], i);
+    public bool Remove(T item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        if (!indexMap.TryGetValue(item, out int index))
+            return false;
+
+        Remove(item, index);
+
+        return true;
+    }
+
+    private void Remove(T item, int index)
+    {
+        int lastIndex = items.Count - 1;
+        T lastItem = items[lastIndex];
+
+        items[index] = lastItem;
+        indexMap[lastItem] = index;
+
+        items.RemoveAt(lastIndex);
+        indexMap.Remove(item);
+    }
+
+    public void Insert(int index, T item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        items.Insert(index, item);
+
+        for (int i = index; i < items.Count; i++)
+            indexMap[items[i]] = i;
+    }
+
+    public void Clear()
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        items.Clear();
+        indexMap.Clear();
+    }
+
+    public bool Contains(T item) => indexMap.ContainsKey(item);
+    public int IndexOf(T item) => items.IndexOf(item);
+    public int BinarySearch(T item, IComparer<T>? comparer = null) => items.BinarySearch(item, comparer);
+
+    public void Sort(IComparer<T> comparer)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        items.Sort(comparer);
+
+        for (int i = 0; i < items.Count; i++)
+            indexMap[items[i]] = i;
+    }
+
+    public void CopyTo(T[] array, int arrayIndex) => items.CopyTo(array, arrayIndex);
+
+    public IEnumerator<T> GetEnumerator() => items.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    public FastList() { }
+    public FastList(int count) { items.Capacity = count; }
+}

Engine.Core/Helpers/FastListOrdered.cs

@@ -0,0 +1,172 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Engine.Core;
+
+/// <summary>
+/// TODO This is VEERY experimental, and doesn't work well with the indices access. Use with caution
+/// </summary>
+/// <typeparam name="TIndex"></typeparam>
+/// <typeparam name="TItem"></typeparam>
+public class FastListOrdered<TIndex, TItem> : IList<TItem>, IReadOnlyList<TItem>, IEnumerable<TItem> where TItem : notnull where TIndex : IComparable
+{
+    private readonly SortedDictionary<TIndex, FastList<TItem>> items = null!;
+
+    private readonly Func<TItem, TIndex> getIndexFunc = null!;
+    private readonly IComparer<TIndex> sortBy = null!;
+
+    private int count = 0;
+    public int Count => count;
+
+    public bool IsReadOnly { get; set; } = false;
+
+    public TItem this[int index]
+    {
+        get { (TIndex tIndex, int i) = GetAt(index); return items[tIndex][i]; }
+        set
+        {
+            if (IsReadOnly)
+                throw new System.Data.ReadOnlyException();
+            (TIndex tIndex, int i) = GetAt(index); items[tIndex][i] = value;
+        }
+    }
+
+    private (TIndex TIndex, int i) GetAt(Index index)
+    {
+        int actualIndex = index.IsFromEnd
+                ? count - index.Value
+                : index.Value;
+
+        if (actualIndex < 0 || actualIndex >= count)
+            throw new IndexOutOfRangeException();
+
+        int leftIndex = actualIndex;
+        foreach ((TIndex i, FastList<TItem> list) in items)
+        {
+            if (leftIndex < list.Count)
+                return (i, leftIndex);
+            leftIndex -= list.Count;
+        }
+        throw new IndexOutOfRangeException();
+    }
+
+    public int IndexOf(TItem item)
+    {
+        int indexCounter = 0;
+        foreach ((TIndex index, FastList<TItem> list) in items)
+        {
+            int i = list.IndexOf(item);
+            if (i != -1)
+                return indexCounter + i;
+            indexCounter += list.Count;
+        }
+
+        return -1;
+    }
+
+    public void Add(TItem item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        TIndex key = getIndexFunc(item);
+        if (!items.TryGetValue(key, out FastList<TItem>? list))
+            items[key] = list = [];
+
+        list.Add(item);
+        count++;
+    }
+
+    public void Insert(int index, TItem item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        TIndex tIndex = getIndexFunc(item);
+        if (!items.TryGetValue(tIndex, out FastList<TItem>? list))
+            items[tIndex] = list = [];
+
+        list.Insert(index, item);
+        count++;
+    }
+
+    public bool Remove(TItem item)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        TIndex index = getIndexFunc(item);
+        if (!items.TryGetValue(index, out FastList<TItem>? list))
+            throw new Exceptions.NotFoundException($"Index of '{index}' is not found in the collector");
+
+        if (!list.Remove(item))
+            return false;
+
+        count--;
+        return true;
+    }
+
+    public void RemoveAt(int index)
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        (TIndex tIndex, int i) = GetAt(index);
+        items[tIndex].RemoveAt(i);
+        count--;
+    }
+
+    public void Clear()
+    {
+        if (IsReadOnly)
+            throw new System.Data.ReadOnlyException();
+
+        foreach ((TIndex index, FastList<TItem> list) in items)
+            list.Clear();
+
+        count = 0;
+    }
+
+    public bool Contains(TItem item)
+    {
+        foreach ((TIndex index, FastList<TItem> list) in items)
+            if (list.Contains(item))
+                return true;
+        return false;
+    }
+
+    public void CopyTo(TItem[] array, int arrayIndex)
+    {
+        int indexCounter = 0;
+
+        foreach ((TIndex index, FastList<TItem> list) in items)
+        {
+            list.CopyTo(array, indexCounter);
+            indexCounter += list.Count;
+        }
+    }
+
+    public IEnumerator<TItem> GetEnumerator()
+    {
+        foreach ((TIndex index, FastList<TItem> list) in items)
+            foreach (TItem item in list)
+                yield return item;
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+    public FastListOrdered(Func<TItem, TIndex> getIndexFunc, Comparison<TIndex> sortBy)
+    {
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = Comparer<TIndex>.Create(sortBy);
+        items = new(this.sortBy);
+    }
+
+    public FastListOrdered(Func<TItem, TIndex> getIndexFunc, IComparer<TIndex> sortBy)
+    {
+        this.getIndexFunc = getIndexFunc;
+        this.sortBy = sortBy;
+        items = new(sortBy);
+    }
+}

Engine.Core/Helpers/IPool.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public interface IPool<T>
 {

Engine.Core/Helpers/ListPool.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public class ListPool<T> : IPool<List<T>>
 {

Engine.Core/Helpers/Pool.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public class Pool<T> : IPool<T>
 {
@@ -10,22 +10,25 @@ public class Pool<T> : IPool<T>
 
     private readonly Func<T> generator = null!;
     private readonly Queue<T> queue = new();
+    private readonly HashSet<T> queuedHashes = [];
 
     public T Get()
     {
         if (!queue.TryDequeue(out T? result))
             result = generator();
 
+        queuedHashes.Remove(result);
         OnRemoved?.Invoke(this, result);
         return result;
     }
 
     public void Return(T item)
     {
-        if (queue.Contains(item))
+        if (queuedHashes.Contains(item))
             return;
 
         queue.Enqueue(item);
+        queuedHashes.Add(item);
         OnReturned?.Invoke(this, item);
     }
 

Engine.Core/Helpers/Progression/IProgressionTracker.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public interface IProgressionTracker : IReadOnlyProgressionTracker
 {

Engine.Core/Helpers/Progression/IReadOnlyProgressionTracker.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public interface IReadOnlyProgressionTracker
 {

Engine.Core/Helpers/Progression/ProgressionTracker.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public class ProgressionTracker : IProgressionTracker
 {

Engine.Core/Helpers/Progression/ProgressiveTask.cs

@@ -1,6 +1,6 @@
 using System.Threading.Tasks;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public record struct ProgressiveTask<T>(IReadOnlyProgressionTracker ProgressionTracker, Task<T> Task)
 {

Engine.Core/Math.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Numerics;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class Math
 {

Engine.Core/MathExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Numerics;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 public static class MathExtensions
 {

Engine.Core/Preserver.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core
+namespace Engine.Core
 {
     // This is pretty much so the assembly gets loaded automatically because 
     // the builds include the assembly but sometimes doesn't link load it at startup.

Engine.Core/Primitives/AABB.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an Axis-Aligned Bounding Box (AABB) in 2D space.

Engine.Core/Primitives/Circle.cs

@@ -1,6 +1,6 @@
 using System.Diagnostics;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a 2D circle.

Engine.Core/Primitives/ColorHSV.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an HSV color.

Engine.Core/Primitives/ColorHSVA.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an HSV color.

Engine.Core/Primitives/ColorRGB.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an RGB color.

Engine.Core/Primitives/ColorRGBA.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an RGBA color.

Engine.Core/Primitives/Line2D.cs

@@ -1,6 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a 2D line segment defined by two endpoints.

Engine.Core/Primitives/Line2DEquation.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a <see cref="Line2DEquation"/> in the form y = mx + b.

Engine.Core/Primitives/Projection1D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a range of values along a single axis.

Engine.Core/Primitives/Quaternion.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a 3D space rotation.

Engine.Core/Primitives/Ray2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents an infinite ray in 2D space.

Engine.Core/Primitives/Shape2D.cs

@@ -1,7 +1,7 @@
 using System.Collections;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a shape defined by a collection of vertices.

Engine.Core/Primitives/Triangle.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 [System.Diagnostics.DebuggerDisplay("A: {A.ToString(), nq}, B: {B.ToString(), nq}, B: {C.ToString(), nq}")]
 public readonly struct Triangle(Vector2D A, Vector2D B, Vector2D C)

Engine.Core/Primitives/Vector2D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a two-dimensional vector.

Engine.Core/Primitives/Vector3D.cs

@@ -1,4 +1,4 @@
-namespace Syntriax.Engine.Core;
+namespace Engine.Core;
 
 /// <summary>
 /// Represents a three-dimensional vector.

Engine.Core/Serialization/Attributes/IgnoreSerializationAttribute.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Class)]
 public class IgnoreSerializationAttribute : Attribute;

Engine.Core/Serialization/Attributes/SerializeAllAttribute.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)]
 public class SerializeAllAttribute : Attribute;

Engine.Core/Serialization/Attributes/SerializeAttribute.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
 public class SerializeAttribute : Attribute;

Engine.Core/Serialization/EntityReference.cs

@@ -1,3 +1,3 @@
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 public record class EntityReference(string? Id = null);

Engine.Core/Serialization/EntityRegistry.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Collections.Generic;
 
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 public class EntityRegistry
 {

Engine.Core/Serialization/ISerializer.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace Syntriax.Engine.Core.Serialization;
+namespace Engine.Core.Serialization;
 
 public interface ISerializer
 {