feat: basic universe object tests

Use IUniverseObject.Children to access children

Engine.Core/Abstract/Assignable/IAssignable.cs

@@ -8,7 +8,7 @@ public interface IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IAssignable"/>'s fields are unassigned and completely ready to recycle.
     /// </summary> 
-    event UnassignEventHandler? OnUnassigned;
+    Event<IAssignable>? OnUnassigned { get; }
 
     /// <summary>
     /// Unassign <see cref="IAssignable"/>'s all fields and make it ready to recycle.
@@ -17,6 +17,4 @@ public interface IAssignable
     /// <see cref="true"/>, if the fields are unsigned successfully, <see cref="false"/> if not.
     /// </returns>
     bool Unassign();
-
-    delegate void UnassignEventHandler(IAssignable sender);
 }

Engine.Core/Abstract/Assignable/IHasBehaviourController.cs

@@ -8,7 +8,7 @@ public interface IHasBehaviourController : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IBehaviourController"/> value has has been assigned a new value.
     /// </summary>
-    event BehaviourControllerAssignedEventHandler? OnBehaviourControllerAssigned;
+    Event<IHasBehaviourController> OnBehaviourControllerAssigned { get; }
 
     /// <inheritdoc cref="IBehaviourController" />
     IBehaviourController BehaviourController { get; }
@@ -21,6 +21,4 @@ public interface IHasBehaviourController : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IBehaviourController behaviourController);
-
-    delegate void BehaviourControllerAssignedEventHandler(IHasBehaviourController sender);
 }

Engine.Core/Abstract/Assignable/IHasEntity.cs

@@ -8,7 +8,7 @@ public interface IHasEntity : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IEntity"/> value has has been assigned a new value.
     /// </summary>
-    event EntityAssignedEventHandler? OnEntityAssigned;
+    Event<IHasEntity> OnEntityAssigned { get; }
 
     /// <inheritdoc cref="IEntity" />
     IEntity Entity { get; }
@@ -21,6 +21,4 @@ public interface IHasEntity : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IEntity entity);
-
-    delegate void EntityAssignedEventHandler(IHasEntity sender);
 }

Engine.Core/Abstract/Assignable/IHasStateEnable.cs

@@ -8,7 +8,7 @@ public interface IHasStateEnable : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IStateEnable"/> value has has been assigned a new value.
     /// </summary>
-    event StateEnableAssignedEventHandler? OnStateEnableAssigned;
+    Event<IHasStateEnable> OnStateEnableAssigned { get; }
 
     /// <inheritdoc cref="IStateEnable" />
     IStateEnable StateEnable { get; }
@@ -21,6 +21,4 @@ public interface IHasStateEnable : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IStateEnable stateEnable);
-
-    delegate void StateEnableAssignedEventHandler(IHasStateEnable sender);
 }

Engine.Core/Abstract/Assignable/IHasUniverse.cs

@@ -8,7 +8,7 @@ public interface IHasUniverse : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IUniverse"/> value has has been assigned a new value.
     /// </summary>
-    event UniverseAssignedEventHandler? OnUniverseAssigned;
+    Event<IHasUniverse> OnUniverseAssigned { get; }
 
     /// <inheritdoc cref="IUniverse" />
     IUniverse Universe { get; }
@@ -21,6 +21,4 @@ public interface IHasUniverse : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IUniverse universe);
-
-    delegate void UniverseAssignedEventHandler(IHasUniverse sender);
 }

Engine.Core/Abstract/Assignable/IHasUniverseObject.cs

@@ -8,7 +8,7 @@ public interface IHasUniverseObject : IAssignable
     /// <summary>
     /// Event triggered when the <see cref="IUniverseObject"/> value has has been assigned a new value.
     /// </summary>
-    event UniverseObjectAssignedEventHandler? OnUniverseObjectAssigned;
+    Event<IHasUniverseObject> OnUniverseObjectAssigned { get; }
 
     /// <inheritdoc cref="IUniverseObject" />
     IUniverseObject UniverseObject { get; }
@@ -21,6 +21,4 @@ public interface IHasUniverseObject : IAssignable
     /// <see cref="true"/>, if the value given assigned successfully assigned, <see cref="false"/> if not.
     /// </returns>
     bool Assign(IUniverseObject universeObject);
-
-    delegate void UniverseObjectAssignedEventHandler(IHasUniverseObject sender);
 }

Engine.Core/Abstract/IActive.cs

@@ -8,12 +8,12 @@ public interface IActive
     /// <summary>
     /// Event triggered when the <see cref="IsActive"/> state of the <see cref="IActive"/> changes.
     /// </summary>
-    event ActiveChangedEventHandler? OnActiveChanged;
+    Event<IActive, ActiveChangedArguments> OnActiveChanged { get; }
 
     /// <summary>
     /// The value indicating whether the <see cref="IActive"/> is enabled.
     /// </summary>
     bool IsActive { get; }
 
-    delegate void ActiveChangedEventHandler(IActive sender, bool previousState);
+    readonly record struct ActiveChangedArguments(bool PreviousState);
 }

Engine.Core/Abstract/IBehaviour.cs

@@ -8,12 +8,12 @@ public interface IBehaviour : IEntity, IActive, IHasBehaviourController, IHasSta
     /// <summary>
     /// Event triggered when the priority of the <see cref="IBehaviour"/> changes.
     /// </summary>
-    event PriorityChangedEventHandler? OnPriorityChanged;
+    Event<IBehaviour, PriorityChangedArguments> OnPriorityChanged { get; }
 
     /// <summary>
     /// The priority of the <see cref="IBehaviour"/>.
     /// </summary>
     int Priority { get; set; }
 
-    delegate void PriorityChangedEventHandler(IBehaviour sender, int previousPriority);
+    readonly record struct PriorityChangedArguments(int PreviousPriority);
 }

Engine.Core/Abstract/IBehaviourCollector.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-
 namespace Syntriax.Engine.Core;
 
 /// <summary>
@@ -7,29 +5,38 @@ namespace Syntriax.Engine.Core;
 /// Provides mechanisms for tracking additions and removals, and notifies subscribers when such events occur on the assigned <see cref="IUniverse"/>.
 /// </summary>
 /// <typeparam name="T">The type of objects tracked by the collector.</typeparam>
-public interface IBehaviourCollector<T> : IHasUniverse, IEnumerable<T> where T : class
+public interface IBehaviourCollector<T> : IHasUniverse where T : class
 {
     /// <summary>
     /// Event triggered when an object of type <typeparamref name="T"/> is added to the collector.
     /// </summary>
-    event CollectedEventHandler? OnCollected;
+    Event<IBehaviourCollector<T>, BehaviourCollectedArguments> OnCollected { get; }
 
     /// <summary>
     /// Event triggered when an object of type <typeparamref name="T"/> is removed from the collector.
     /// </summary>
-    event RemovedEventHandler? OnRemoved;
+    Event<IBehaviourCollector<T>, BehaviourRemovedArguments> OnRemoved { get; }
+
+    /// <summary>
+    /// Amount of <typeparamref name="T"/> collected.
+    /// </summary>
+    int Count { get; }
+
+    /// <summary>
+    /// Get a <typeparamref name="T"/> collected by it's index.
+    /// </summary>
+    T this[System.Index index] { get; }
 
     /// <summary>
     /// Delegate for handling the <see cref="OnCollected"/> event.
     /// </summary>
     /// <param name="sender">The instance of the <see cref="IBehaviourCollector{T}"/> that triggered the event.</param>
     /// <param name="behaviourCollected">The object of type <typeparamref name="T"/> that was added to the collector.</param>
-    delegate void CollectedEventHandler(IBehaviourCollector<T> sender, T behaviourCollected);
+    readonly record struct BehaviourCollectedArguments(T BehaviourCollected);
 
     /// <summary>
     /// Delegate for handling the <see cref="OnRemoved"/> event.
     /// </summary>
-    /// <param name="sender">The instance of the <see cref="IBehaviourCollector{T}"/> that triggered the event.</param>
-    /// <param name="behaviourRemoved">The object of type <typeparamref name="T"/> that was removed from the collector.</param>
-    delegate void RemovedEventHandler(IBehaviourCollector<T> sender, T behaviourRemoved);
+    /// <param name="BehaviourRemoved">The object of type <typeparamref name="T"/> that was removed from the collector.</param>
+    readonly record struct BehaviourRemovedArguments(T BehaviourRemoved);
 }

Engine.Core/Abstract/IBehaviourController.cs

@@ -3,34 +3,29 @@ using System.Collections.Generic;
 namespace Syntriax.Engine.Core;
 
 /// <summary>
-/// Represents a controller for managing <see cref="IBehaviour"/>s and notify them accordingly about the engine's updates. Connected to an <see cref="IUniverseObject"/>.
+/// Represents a controller for managing <see cref="IBehaviour"/>s. Connected to an <see cref="IUniverseObject"/>.
 /// </summary>
-public interface IBehaviourController : IEntity, IHasUniverseObject, IEnumerable<IBehaviour>
+public interface IBehaviourController : IEntity, IHasUniverseObject
 {
-    /// <summary>
-    /// Event triggered before the update of <see cref="IBehaviour"/>s.
-    /// </summary>
-    event PreUpdateEventHandler? OnPreUpdate;
-
-    /// <summary>
-    /// Event triggered during the update of <see cref="IBehaviour"/>s.
-    /// </summary>
-    event UpdateEventHandler? OnUpdate;
-
-    /// <summary>
-    /// Event triggered before the drawing phase.
-    /// </summary>
-    event PreDrawEventHandler? OnPreDraw;
-
     /// <summary>
     /// Event triggered when a <see cref="IBehaviour"/> is added to the <see cref="IBehaviourController"/>.
     /// </summary>
-    event BehaviourAddedEventHandler? OnBehaviourAdded;
+    Event<IBehaviourController, BehaviourAddedArguments> OnBehaviourAdded { get; }
 
     /// <summary>
     /// Event triggered when a <see cref="IBehaviour"/> is removed from the <see cref="IBehaviourController"/>.
     /// </summary>
-    event BehaviourRemovedEventHandler? OnBehaviourRemoved;
+    Event<IBehaviourController, BehaviourRemovedArguments> OnBehaviourRemoved { get; }
+
+    /// <summary>
+    /// Amount of <see cref="IBehaviour"/> collected.
+    /// </summary>
+    int Count { get; }
+
+    /// <summary>
+    /// Get a <see cref="IBehaviour"/> collected by it's index.
+    /// </summary>
+    IBehaviour this[System.Index index] { get; }
 
     /// <summary>
     /// Adds a <see cref="IBehaviour"/> to the <see cref="IBehaviourController"/>.
@@ -83,20 +78,6 @@ public interface IBehaviourController : IEntity, IHasUniverseObject, IEnumerable
     /// <param name="behaviour">The <see cref="IBehaviour"/> to remove.</param>
     void RemoveBehaviour<T>(T behaviour) where T : class, IBehaviour;
 
-    /// <summary>
-    /// Updates all <see cref="IBehaviour"/>s in the <see cref="IBehaviourController"/>.
-    /// </summary>
-    void Update();
-
-    /// <summary>
-    /// Performs pre-draw operations.
-    /// </summary>
-    void UpdatePreDraw();
-
-    delegate void PreUpdateEventHandler(IBehaviourController sender);
-    delegate void UpdateEventHandler(IBehaviourController sender);
-    delegate void PreDrawEventHandler(IBehaviourController sender);
-    delegate void BehaviourAddedEventHandler(IBehaviourController sender, IBehaviour behaviourAdded);
-    delegate void BehaviourRemovedEventHandler(IBehaviourController sender, IBehaviour behaviourRemoved);
-
+    readonly record struct BehaviourAddedArguments(IBehaviour BehaviourAdded);
+    readonly record struct BehaviourRemovedArguments(IBehaviour BehaviourRemoved);
 }

Engine.Core/Abstract/IEntity.cs

@@ -9,12 +9,12 @@ public interface IEntity : IInitializable, IHasStateEnable
     /// Event triggered when the <see cref="Id"/> of the <see cref="IEntity"/> changes.
     /// The string action parameter is the previous <see cref="Id"/> of the <see cref="IEntity"/>. 
     /// </summary>
-    event IdChangedEventHandler? OnIdChanged;
+    Event<IEntity, IdChangedArguments> OnIdChanged { get; }
 
     /// <summary>
     /// The ID of the <see cref="IEntity"/>.
     /// </summary>
     string Id { get; set; }
 
-    delegate void IdChangedEventHandler(IEntity sender, string previousId);
+    readonly record struct IdChangedArguments(string PreviousId);
 }

Engine.Core/Abstract/IInitializable.cs

@@ -8,12 +8,12 @@ public interface IInitializable
     /// <summary>
     /// Event triggered when the <see cref="Initialize"/> method is called successfully.
     /// </summary>
-    event InitializedEventHandler? OnInitialized;
+    Event<IInitializable> OnInitialized { get; }
 
     /// <summary>
     /// Event triggered when the <see cref="IInitializable"/> method is called successfully.
     /// </summary>
-    event FinalizedEventHandler? OnFinalized;
+    Event<IInitializable> OnFinalized { get; }
 
     /// <summary>
     /// The value indicating whether the entity has been initialized.
@@ -31,7 +31,4 @@ public interface IInitializable
     /// </summary>
     /// <returns><see cref="true"/> if finalization is successful, otherwise <see cref="false"/>.</returns>
     bool Finalize();
-
-    delegate void InitializedEventHandler(IInitializable sender);
-    delegate void FinalizedEventHandler(IInitializable sender);
 }

Engine.Core/Abstract/INameable.cs

@@ -8,12 +8,12 @@ public interface INameable
     /// <summary>
     /// Event triggered when the name of the entity changes.
     /// </summary>
-    event NameChangedEventHandler? OnNameChanged;
+    Event<INameable, NameChangedArguments> OnNameChanged { get; }
 
     /// <summary>
     /// The name of the entity.
     /// </summary>
     string Name { get; set; }
 
-    delegate void NameChangedEventHandler(INameable sender, string previousName);
+    readonly record struct NameChangedArguments(string PreviousName);
 }

Engine.Core/Abstract/IStateEnable.cs

@@ -8,12 +8,12 @@ public interface IStateEnable : IHasEntity
     /// <summary>
     /// Event triggered when the <see cref="Enabled"/> state of the <see cref="IStateEnable"/> changes.
     /// </summary>
-    event EnabledChangedEventHandler? OnEnabledChanged;
+    Event<IStateEnable, EnabledChangedArguments> OnEnabledChanged { get; }
 
     /// <summary>
     /// The value indicating whether the <see cref="IStateEnable"/> is enabled.
     /// </summary>
     bool Enabled { get; set; }
 
-    delegate void EnabledChangedEventHandler(IStateEnable sender, bool previousState);
+    readonly record struct EnabledChangedArguments(bool PreviousState);
 }

Engine.Core/Abstract/ITransform2D.cs

@@ -8,17 +8,37 @@ public interface ITransform2D : IBehaviour
     /// <summary>
     /// Event triggered when the <see cref="Position"/> of the <see cref="ITransform2D"/> changes.
     /// </summary>
-    event PositionChangedEventHandler? OnPositionChanged;
+    Event<ITransform2D, PositionChangedArguments> OnPositionChanged { get; }
 
     /// <summary>
     /// Event triggered when the <see cref="Scale"/> of the <see cref="ITransform2D"/> changes.
     /// </summary>
-    event ScaleChangedEventHandler? OnScaleChanged;
+    Event<ITransform2D, ScaleChangedArguments> OnScaleChanged { get; }
 
     /// <summary>
     /// Event triggered when the <see cref="Rotation"/> of the <see cref="ITransform"/> changes.
     /// </summary>
-    event RotationChangedEventHandler? OnRotationChanged;
+    Event<ITransform2D, RotationChangedArguments> OnRotationChanged { get; }
+
+    /// <summary>
+    /// The <see cref="Vector2D"/> pointing upwards in world space.
+    /// </summary>
+    Vector2D Up { get; }
+
+    /// <summary>
+    /// The <see cref="Vector2D"/> pointing upwards in world space.
+    /// </summary>
+    Vector2D Down { get; }
+
+    /// <summary>
+    /// The <see cref="Vector2D"/> pointing upwards in world space.
+    /// </summary>
+    Vector2D Left { get; }
+
+    /// <summary>
+    /// The <see cref="Vector2D"/> pointing upwards in world space.
+    /// </summary>
+    Vector2D Right { get; }
 
     /// <summary>
     /// The world position of the <see cref="ITransform2D"/> in 2D space.
@@ -51,23 +71,20 @@ public interface ITransform2D : IBehaviour
     float LocalRotation { get; set; }
 
     /// <summary>
-    /// Delegate for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
+    /// Arguments for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
     /// </summary>
-    /// <param name="sender">The <see cref="ITransform2D"/> that the parent has changed.</param>
-    /// <param name="previousPosition">The previous <see cref="Position"/> of the <see cref="ITransform2D"/>.</param>
-    delegate void PositionChangedEventHandler(ITransform2D sender, Vector2D previousPosition);
+    /// <param name="PreviousPosition">The previous <see cref="Position"/> of the <see cref="ITransform2D"/>.</param>
+    readonly record struct PositionChangedArguments(Vector2D PreviousPosition);
 
     /// <summary>
-    /// Delegate for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
+    /// Arguments for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
     /// </summary>
-    /// <param name="sender">The <see cref="ITransform2D"/> that the parent has changed.</param>
-    /// <param name="previousScale">The previous <see cref="Scale"/> of the <see cref="ITransform2D"/>.</param>
-    delegate void ScaleChangedEventHandler(ITransform2D sender, Vector2D previousScale);
+    /// <param name="PreviousScale">The previous <see cref="Scale"/> of the <see cref="ITransform2D"/>.</param>
+    readonly record struct ScaleChangedArguments(Vector2D PreviousScale);
 
     /// <summary>
-    /// Delegate for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
+    /// Arguments for the event triggered when the <see cref="ITransform2D"/>'s rotation changes.
     /// </summary>
-    /// <param name="sender">The <see cref="ITransform2D"/> that the parent has changed.</param>
-    /// <param name="previousRotation">The previous <see cref="Rotation"/> of the <see cref="ITransform2D"/>.</param>
-    delegate void RotationChangedEventHandler(ITransform2D sender, float previousRotation);
+    /// <param name="PreviousRotation">The previous <see cref="Rotation"/> of the <see cref="ITransform2D"/>.</param>
+    readonly record struct RotationChangedArguments(float PreviousRotation);
 }

Engine.Core/Abstract/IUniverse.cs

@@ -10,32 +10,57 @@ public interface IUniverse : IEntity, IEnumerable<IUniverseObject>
     /// <summary>
     /// Event triggered when <see cref="Update(UniverseTime)"/> is about to be called called on the <see cref="IUniverse"/>.
     /// </summary>
-    event UpdateEventHandler? OnPreUpdate;
+    Event<IUniverse, UpdateArguments> OnPreUpdate { get; }
 
     /// <summary>
     /// Event triggered when <see cref="Update(UniverseTime)"/> is called on the <see cref="IUniverse"/>.
     /// </summary>
-    event UpdateEventHandler? OnUpdate;
+    Event<IUniverse, UpdateArguments> OnUpdate { get; }
 
     /// <summary>
-    /// Event triggered when <see cref="PreDraw"/> is called on the <see cref="IUniverse"/>.
+    /// Event triggered after <see cref="Update(UniverseTime)"/> is called on the <see cref="IUniverse"/>.
     /// </summary>
-    event PreDrawEventHandler? OnPreDraw;
+    Event<IUniverse, UpdateArguments> OnPostUpdate { get; }
+
+    /// <summary>
+    /// Event triggered when <see cref="Draw"/> is about to be called called on the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse> OnPreDraw { get; }
+
+    /// <summary>
+    /// Event triggered when <see cref="Draw"/> is called on the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse> OnDraw { get; }
+
+    /// <summary>
+    /// Event triggered after <see cref="Draw"/> is called on the <see cref="IUniverse"/>.
+    /// </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 UniverseObjectRegisteredEventHandler? OnUniverseObjectRegistered;
+    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>
-    event UniverseObjectUnRegisteredEventHandler? OnUniverseObjectUnRegistered;
+    Event<IUniverse, UniverseObjectUnRegisteredArguments> OnUniverseObjectUnRegistered { get; }
 
     /// <summary>
     /// Event triggered when <see cref="TimeScale"/> is changed on the <see cref="IUniverse"/>.
     /// </summary>
-    event TimeScaleChangedEventHandler? OnTimeScaleChanged;
+    Event<IUniverse, TimeScaleChangedArguments> OnTimeScaleChanged { get; }
 
     /// <summary>
     /// Current time scale the <see cref="IUniverse"/> operates on.
@@ -84,15 +109,12 @@ public interface IUniverse : IEntity, IEnumerable<IUniverseObject>
     void Update(UniverseTime universeTime);
 
     /// <summary>
-    /// Performs operations that should be done before the draw calls.
+    /// Performs operations that should be done to the draw.
     /// </summary>
-    void PreDraw();
+    void Draw();
 
-    delegate void TimeScaleChangedEventHandler(IUniverse sender, float previousTimeScale);
-
-    delegate void UpdateEventHandler(IUniverse sender, UniverseTime engineTime);
-    delegate void PreDrawEventHandler(IUniverse sender);
-
-    delegate void UniverseObjectRegisteredEventHandler(IUniverse sender, IUniverseObject universeObjectRegistered);
-    delegate void UniverseObjectUnRegisteredEventHandler(IUniverse sender, IUniverseObject universeObjectUnregistered);
+    readonly record struct TimeScaleChangedArguments(float PreviousTimeScale);
+    readonly record struct UpdateArguments(UniverseTime EngineTime);
+    readonly record struct UniverseObjectRegisteredArguments(IUniverseObject UniverseObjectRegistered);
+    readonly record struct UniverseObjectUnRegisteredArguments(IUniverseObject UniverseObjectUnregistered);
 }

Engine.Core/Abstract/IUniverseObject.cs

@@ -7,32 +7,32 @@ namespace Syntriax.Engine.Core;
 /// 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.
     /// </summary>
-    event EnteredUniverseEventHandler? OnEnteredUniverse;
+    Event<IUniverseObject, EnteredUniverseArguments> OnEnteredUniverse { get; }
 
     /// <summary>
     /// Event triggered when the <see cref="IUniverseObject"/> exits the universe.
     /// </summary>
-    event ExitedUniverseEventHandler? OnExitedUniverse;
+    Event<IUniverseObject, ExitedUniverseArguments> OnExitedUniverse { get; }
 
     /// <summary>
     /// Event triggered when the <see cref="Parent"/> of the <see cref="IUniverseObject"/> changes. The second parameter is the old <see cref="IUniverseObject"/>.
     /// </summary>
-    event ParentChangedEventHandler? OnParentChanged;
+    Event<IUniverseObject, ParentChangedArguments> OnParentChanged { get; }
 
     /// <summary>
     /// Event triggered when a new <see cref="IUniverseObject"/> is added to the <see cref="Children"/>.
     /// </summary>
-    event ChildrenAddedEventHandler? OnChildrenAdded;
+    Event<IUniverseObject, ChildrenAddedArguments> OnChildrenAdded { get; }
 
     /// <summary>
     /// Event triggered when an <see cref="IUniverseObject"/> is removed from the <see cref="Children"/>.
     /// </summary>
-    event ChildrenRemovedEventHandler? OnChildrenRemoved;
+    Event<IUniverseObject, ChildrenRemovedArguments> OnChildrenRemoved { get; }
 
     /// <summary>
     /// Gets the <see cref="IUniverse"/> this <see cref="IUniverseObject"/> is connected to, if any.
@@ -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>
@@ -94,38 +88,38 @@ public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourCon
     void RemoveChild(IUniverseObject universeObject);
 
     /// <summary>
-    /// EventHandler delegate for the event triggered when the <see cref="IUniverseObject"/> enters the universe of a <see cref="IUniverse">.
+    /// Arguments for the event triggered when the <see cref="IUniverseObject"/> enters the universe of a <see cref="IUniverse">.
     /// </summary>
     /// <param name="sender">The <see cref="IUniverseObject"/> that entered the universe.</param>
     /// <param name="universe">The <see cref="IUniverse"/> that the <see cref="IUniverseObject"/> has entered it's universe.</param>
-    delegate void EnteredUniverseEventHandler(IUniverseObject sender, IUniverse universe);
+    readonly record struct EnteredUniverseArguments(IUniverse Universe);
 
     /// <summary>
-    /// EventHandler delegate for the event triggered when the <see cref="IUniverseObject"/> exits the universe of a <see cref="IUniverse">.
+    /// Arguments for the event triggered when the <see cref="IUniverseObject"/> exits the universe of a <see cref="IUniverse">.
     /// </summary>
     /// <param name="sender">The <see cref="IUniverseObject"/> that exited the universe.</param>
     /// <param name="universe">The <see cref="IUniverse"/> that the <see cref="IUniverseObject"/> has exited it's universe.</param>
-    delegate void ExitedUniverseEventHandler(IUniverseObject sender, IUniverse universe);
+    readonly record struct ExitedUniverseArguments(IUniverse Universe);
 
     /// <summary>
-    /// Delegate for the event triggered when the <see cref="IUniverseObject"/>'s parent changes.
+    /// Arguments for the event triggered when the <see cref="IUniverseObject"/>'s parent changes.
     /// </summary>
     /// <param name="sender">The <see cref="IUniverseObject"/> that the parent has changed.</param>
     /// <param name="previousParent">The previous <see cref="IUniverseObject"/> the sender was a child of.</param>
     /// <param name="newParent">The new and current <see cref="IUniverseObject"/> the sender is a child of.</param>
-    delegate void ParentChangedEventHandler(IUniverseObject sender, IUniverseObject? previousParent, IUniverseObject? newParent);
+    readonly record struct ParentChangedArguments(IUniverseObject? PreviousParent, IUniverseObject? CurrentParent);
 
     /// <summary>
-    /// Delegate for the event triggered when a new <see cref="IUniverseObject"/> added as a child.
+    /// Arguments for the event triggered when a new <see cref="IUniverseObject"/> added as a child.
     /// </summary>
     /// <param name="sender">The parent <see cref="IUniverseObject"/> this event is being called from.</param>
     /// <param name="childrenAdded">The <see cref="IUniverseObject"/> that got removed as a children of the sender <see cref="IUniverseObject"/>.</param>
-    delegate void ChildrenAddedEventHandler(IUniverseObject sender, IUniverseObject childrenAdded);
+    readonly record struct ChildrenAddedArguments(IUniverseObject ChildrenAdded);
 
     /// <summary>
     /// Delegate for the event triggered when a new <see cref="IUniverseObject"/> removed from being a child.
     /// </summary>
     /// <param name="sender">The parent <see cref="IUniverseObject"/> this event is being called from.</param>
     /// <param name="childrenAdded">The <see cref="IUniverseObject"/> that got removed as a children of the sender <see cref="IUniverseObject"/>.</param>
-    delegate void ChildrenRemovedEventHandler(IUniverseObject sender, IUniverseObject childrenRemoved);
+    readonly record struct ChildrenRemovedArguments(IUniverseObject ChildrenRemoved);
 }

Engine.Core/ActiveBehaviourCollector.cs

@@ -1,89 +1,92 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
 public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : class, IBehaviour
 {
-    public event IAssignable.UnassignEventHandler? OnUnassigned = null;
-    public event IHasUniverse.UniverseAssignedEventHandler? OnUniverseAssigned = null;
+    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 event IBehaviourCollector<T>.CollectedEventHandler? OnCollected = null;
-    public event IBehaviourCollector<T>.RemovedEventHandler? OnRemoved = null;
+    private readonly Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments>.EventHandler delegateOnBehaviourAdded = null!;
+    private readonly Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments>.EventHandler delegateOnBehaviourRemoved = null!;
+    private readonly Event<IActive, IActive.ActiveChangedArguments>.EventHandler delegateOnBehaviourStateChanged = null!;
+    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);
     protected readonly List<T> activeBehaviours = new(32);
     protected readonly Dictionary<IActive, T> monitoringActiveToBehaviour = new(32);
 
-    public IReadOnlyList<T> Behaviours => activeBehaviours;
     public IUniverse Universe { get; private set; } = null!;
 
-    public T this[Index index] => activeBehaviours[index];
-
-    public ActiveBehaviourCollector() { }
-    public ActiveBehaviourCollector(IUniverse universe) => Assign(universe);
-
-    private void OnUniverseObjectRegistered(IUniverse manager, IUniverseObject universeObject)
+    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
     {
-        universeObject.BehaviourController.OnBehaviourAdded += OnBehaviourAdded;
-        universeObject.BehaviourController.OnBehaviourRemoved += OnBehaviourRemoved;
+        IUniverseObject universeObject = args.UniverseObjectRegistered;
 
-        foreach (IBehaviour item in universeObject.BehaviourController)
-            OnBehaviourAdded(universeObject.BehaviourController, item);
+        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, IUniverseObject universeObject)
+    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
     {
-        universeObject.BehaviourController.OnBehaviourAdded -= OnBehaviourAdded;
-        universeObject.BehaviourController.OnBehaviourRemoved -= OnBehaviourRemoved;
+        IUniverseObject universeObject = args.UniverseObjectUnregistered;
 
-        foreach (IBehaviour item in universeObject.BehaviourController)
-            OnBehaviourRemoved(universeObject.BehaviourController, item);
+        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, IBehaviour behaviour)
+    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
     {
-        if (behaviour is not T tBehaviour)
+        if (args.BehaviourAdded is not T tBehaviour)
             return;
 
         monitoringBehaviours.Add(tBehaviour);
         monitoringActiveToBehaviour.Add(tBehaviour, tBehaviour);
-        tBehaviour.OnActiveChanged += OnBehaviourStateChanged;
-        OnBehaviourStateChanged(tBehaviour, !tBehaviour.IsActive);
+        tBehaviour.OnActiveChanged.AddListener(delegateOnBehaviourStateChanged);
+        OnBehaviourStateChanged(tBehaviour, new(!tBehaviour.IsActive));
     }
 
-    private void OnBehaviourStateChanged(IActive sender, bool previousState)
+    protected virtual void AddBehaviour(T behaviour) => activeBehaviours.Add(behaviour);
+    private void OnBehaviourStateChanged(IActive sender, IActive.ActiveChangedArguments args)
     {
         T behaviour = monitoringActiveToBehaviour[sender];
         if (sender.IsActive)
         {
-            activeBehaviours.Add(behaviour);
+            AddBehaviour(behaviour);
             OnBehaviourAdd(behaviour);
-            OnCollected?.InvokeSafe(this, behaviour);
+            OnCollected?.Invoke(this, new(behaviour));
         }
         else if (activeBehaviours.Remove(behaviour))
         {
             OnBehaviourRemove(behaviour);
-            OnRemoved?.InvokeSafe(this, behaviour);
+            OnRemoved?.Invoke(this, new(behaviour));
         }
     }
 
     protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
-    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviour behaviour)
+    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
     {
-        if (behaviour is not T tBehaviour)
+        if (args.BehaviourRemoved is not T tBehaviour)
             return;
 
         if (!monitoringBehaviours.Remove(tBehaviour) || !monitoringActiveToBehaviour.Remove(tBehaviour))
             return;
 
-        tBehaviour.OnActiveChanged -= OnBehaviourStateChanged;
+        tBehaviour.OnActiveChanged.RemoveListener(delegateOnBehaviourStateChanged);
         if (activeBehaviours.Remove(tBehaviour))
         {
             OnBehaviourRemove(tBehaviour);
-            OnRemoved?.InvokeSafe(this, tBehaviour);
+            OnRemoved?.Invoke(this, new(tBehaviour));
         }
     }
 
@@ -93,13 +96,13 @@ public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : clas
             return false;
 
         foreach (IUniverseObject universeObject in universe.UniverseObjects)
-            OnUniverseObjectRegistered(universe, universeObject);
+            OnUniverseObjectRegistered(universe, new(universeObject));
 
-        universe.OnUniverseObjectRegistered += OnUniverseObjectRegistered;
-        universe.OnUniverseObjectUnRegistered += OnUniverseObjectUnregistered;
+        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
+        universe.OnUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
 
         Universe = universe;
-        OnUniverseAssigned?.InvokeSafe(this);
+        OnUniverseAssigned?.Invoke(this);
 
         return true;
     }
@@ -110,16 +113,36 @@ public class ActiveBehaviourCollector<T> : IBehaviourCollector<T> where T : clas
             return false;
 
         foreach (IUniverseObject universeObject in Universe.UniverseObjects)
-            OnUniverseObjectUnregistered(Universe, universeObject);
+            OnUniverseObjectUnregistered(Universe, new(universeObject));
 
-        Universe.OnUniverseObjectRegistered -= OnUniverseObjectRegistered;
-        Universe.OnUniverseObjectUnRegistered -= OnUniverseObjectUnregistered;
+        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
+        Universe.OnUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
 
         Universe = null!;
-        OnUnassigned?.InvokeSafe(this);
+        OnUnassigned?.Invoke(this);
         return true;
     }
 
-    public IEnumerator<T> GetEnumerator() => activeBehaviours.GetEnumerator();
-    IEnumerator IEnumerable.GetEnumerator() => activeBehaviours.GetEnumerator();
+    public int Count => activeBehaviours.Count;
+    public T this[Index index] => activeBehaviours[index];
+
+    public ActiveBehaviourCollector()
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+    }
+
+    public ActiveBehaviourCollector(IUniverse universe)
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnBehaviourStateChanged = OnBehaviourStateChanged;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+
+        Assign(universe);
+    }
 }

Engine.Core/ActiveBehaviourCollectorSorted.cs

@@ -1,11 +1,14 @@
 using System;
+using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
 public class ActiveBehaviourCollectorSorted<T> : ActiveBehaviourCollector<T> where T : class, IBehaviour
 {
-    private Comparison<T>? _sortBy = null;
-    public Comparison<T>? SortBy
+    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
+
+    private IComparer<T>? _sortBy = null;
+    public IComparer<T>? SortBy
     {
         get => _sortBy;
         set
@@ -17,12 +20,48 @@ public class ActiveBehaviourCollectorSorted<T> : ActiveBehaviourCollector<T> whe
         }
     }
 
-    protected override void OnBehaviourAdd(IBehaviour behaviour)
+    protected override void AddBehaviour(T behaviour)
     {
-        if (SortBy is not null)
-            activeBehaviours.Sort(SortBy);
+        if (SortBy is null)
+        {
+            activeBehaviours.Add(behaviour);
+            return;
+        }
+
+        int insertionIndex = activeBehaviours.BinarySearch(behaviour, SortBy);
+
+        if (insertionIndex < 0)
+            insertionIndex = ~insertionIndex;
+
+        activeBehaviours.Insert(insertionIndex, behaviour);
     }
 
-    public ActiveBehaviourCollectorSorted() { }
-    public ActiveBehaviourCollectorSorted(IUniverse universe, Comparison<T> sortBy) : base(universe) => SortBy = sortBy;
+    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

@@ -4,13 +4,11 @@ namespace Syntriax.Engine.Core;
 
 public abstract class BaseEntity : IEntity
 {
-    public event IEntity.IdChangedEventHandler? OnIdChanged = null;
-
-    public event IInitializable.InitializedEventHandler? OnInitialized = null;
-    public event IInitializable.FinalizedEventHandler? OnFinalized = null;
-
-    public event IHasStateEnable.StateEnableAssignedEventHandler? OnStateEnableAssigned = null;
-    public event IAssignable.UnassignEventHandler? OnUnassigned = null;
+    public Event<IEntity, IEntity.IdChangedArguments> OnIdChanged { get; } = new();
+    public Event<IInitializable> OnInitialized { get; } = new();
+    public Event<IInitializable> OnFinalized { get; } = new();
+    public Event<IHasStateEnable> OnStateEnableAssigned { get; } = new();
+    public Event<IAssignable> OnUnassigned { get; } = new();
 
     private IStateEnable _stateEnable = null!;
 
@@ -33,7 +31,7 @@ public abstract class BaseEntity : IEntity
             string previousId = _id;
 
             _id = value;
-            OnIdChanged?.InvokeSafe(this, previousId);
+            OnIdChanged?.Invoke(this, new(previousId));
         }
     }
 
@@ -47,9 +45,9 @@ public abstract class BaseEntity : IEntity
 
             _initialized = value;
             if (value)
-                OnInitialized?.InvokeSafe(this);
+                OnInitialized?.Invoke(this);
             else
-                OnFinalized?.InvokeSafe(this);
+                OnFinalized?.Invoke(this);
         }
     }
 
@@ -62,7 +60,7 @@ public abstract class BaseEntity : IEntity
         _stateEnable = stateEnable;
         _stateEnable.Assign(this);
         OnAssign(stateEnable);
-        OnStateEnableAssigned?.InvokeSafe(this);
+        OnStateEnableAssigned?.Invoke(this);
         return true;
     }
 
@@ -76,7 +74,7 @@ public abstract class BaseEntity : IEntity
 
         _stateEnable = null!;
         _stateEnable.Unassign();
-        OnUnassigned?.InvokeSafe(this);
+        OnUnassigned?.Invoke(this);
         return true;
     }
 

Engine.Core/Behaviour.cs

@@ -2,108 +2,49 @@ namespace Syntriax.Engine.Core;
 
 public abstract class Behaviour : BehaviourBase
 {
-    private bool isInitializedThisFrame = false;
-
-    protected IUniverse Universe => BehaviourController.UniverseObject.Universe;
-    protected IUniverseObject UniverseObject => BehaviourController.UniverseObject;
+    private readonly Event<IUniverseObject, IUniverseObject.EnteredUniverseArguments>.EventHandler delegateEnteredUniverse = null!;
+    private readonly Event<IUniverseObject, IUniverseObject.ExitedUniverseArguments>.EventHandler delegateExitedUniverse = null!;
 
     public Behaviour()
     {
-        OnInitialized += OnInitialize;
-        OnFinalized += OnFinalize;
-        OnUnassigned += OnUnassign;
+        OnInitialized.AddListener(OnInitialize);
+        OnFinalized.AddListener(OnFinalize);
+        OnUnassigned.AddListener(OnUnassign);
+
+        delegateEnteredUniverse = EnteredUniverse;
+        delegateExitedUniverse = ExitedUniverse;
     }
 
     protected virtual void OnUnassign() { }
-    protected virtual void OnUnassign(IAssignable assignable) => OnUnassign();
+    protected void OnUnassign(IAssignable assignable) => OnUnassign();
 
     protected virtual void OnInitialize() { }
-    protected virtual void OnInitialize(IInitializable _)
+    protected void OnInitialize(IInitializable _)
     {
-        isInitializedThisFrame = true;
-
-        BehaviourController.OnPreUpdate += PreUpdate;
-        BehaviourController.OnPreDraw += PreDraw;
-        BehaviourController.OnUpdate += Update;
-        BehaviourController.UniverseObject.OnEnteredUniverse += EnteredUniverse;
-        BehaviourController.UniverseObject.OnExitedUniverse += ExitedUniverse;
+        BehaviourController.UniverseObject.OnEnteredUniverse.AddListener(delegateEnteredUniverse);
+        BehaviourController.UniverseObject.OnExitedUniverse.AddListener(delegateExitedUniverse);
 
         OnInitialize();
 
         if (UniverseObject.IsInUniverse)
-            EnteredUniverse(UniverseObject, Universe);
+            EnteredUniverse(UniverseObject, new(Universe));
     }
 
     protected virtual void OnFinalize() { }
-    protected virtual void OnFinalize(IInitializable _)
+    protected void OnFinalize(IInitializable _)
     {
-        BehaviourController.OnPreUpdate -= PreUpdate;
-        BehaviourController.OnPreDraw -= PreDraw;
-        BehaviourController.OnUpdate -= Update;
-        BehaviourController.UniverseObject.OnEnteredUniverse -= EnteredUniverse;
-        BehaviourController.UniverseObject.OnExitedUniverse -= ExitedUniverse;
+        BehaviourController.UniverseObject.OnEnteredUniverse.RemoveListener(delegateEnteredUniverse);
+        BehaviourController.UniverseObject.OnExitedUniverse.RemoveListener(delegateExitedUniverse);
 
         OnFinalize();
 
         if (UniverseObject.IsInUniverse)
-            ExitedUniverse(UniverseObject, Universe);
-    }
-
-    protected virtual void OnPreUpdatePreActiveCheck() { }
-    protected virtual void OnPreUpdate() { }
-    protected virtual void PreUpdate(IBehaviourController _)
-    {
-        Debug.Assert.AssertInitialized(this);
-
-        OnPreUpdatePreActiveCheck();
-
-        if (!IsActive)
-            return;
-
-        if (isInitializedThisFrame)
-            FirstActiveFrame();
-
-        OnPreUpdate();
-    }
-
-    protected virtual void OnFirstActiveFrame() { }
-    protected virtual void FirstActiveFrame()
-    {
-        OnFirstActiveFrame();
-        isInitializedThisFrame = false;
-    }
-
-    protected virtual void OnUpdatePreActiveCheck() { }
-    protected virtual void OnUpdate() { }
-    protected virtual void Update(IBehaviourController _)
-    {
-        Debug.Assert.AssertInitialized(this);
-
-        OnUpdatePreActiveCheck();
-
-        if (!IsActive)
-            return;
-
-        OnUpdate();
-    }
-
-    protected virtual void OnPreDrawPreActiveCheck() { }
-    protected virtual void OnPreDraw() { }
-    protected virtual void PreDraw(IBehaviourController _)
-    {
-        Debug.Assert.AssertInitialized(this);
-
-        OnPreDrawPreActiveCheck();
-
-        if (!StateEnable.Enabled)
-            return;
-
-        OnPreDraw();
+            ExitedUniverse(UniverseObject, new(Universe));
     }
 
     protected virtual void OnEnteredUniverse(IUniverse universe) { }
-    protected virtual void EnteredUniverse(IUniverseObject sender, IUniverse universe) => OnEnteredUniverse(universe);
+    protected void EnteredUniverse(IUniverseObject sender, IUniverseObject.EnteredUniverseArguments args) => OnEnteredUniverse(args.Universe);
 
     protected virtual void OnExitedUniverse(IUniverse universe) { }
-    protected virtual void ExitedUniverse(IUniverseObject sender, IUniverse universe) => OnExitedUniverse(universe);
+    protected void ExitedUniverse(IUniverseObject sender, IUniverseObject.ExitedUniverseArguments args) => OnExitedUniverse(args.Universe);
 }

Engine.Core/Behaviour2D.cs

@@ -4,23 +4,6 @@ public abstract class Behaviour2D : Behaviour, IBehaviour2D
 {
     public ITransform2D Transform { get; private set; } = null!;
 
-    protected sealed override void OnInitialize(IInitializable _)
-    {
-        Transform = BehaviourController.GetRequiredBehaviour<ITransform2D>();
-        base.OnInitialize(_);
-    }
-
-    protected sealed override void OnFinalize(IInitializable _)
-    {
-        Transform = null!;
-        base.OnFinalize(_);
-    }
-
-    protected sealed override void OnUnassign(IAssignable assignable) => base.OnUnassign(assignable);
-    protected sealed override void PreUpdate(IBehaviourController behaviourController) => base.PreUpdate(behaviourController);
-    protected sealed override void FirstActiveFrame() => base.FirstActiveFrame();
-    protected sealed override void Update(IBehaviourController behaviourController) => base.Update(behaviourController);
-    protected sealed override void PreDraw(IBehaviourController behaviourController) => base.PreDraw(behaviourController);
-    protected sealed override void EnteredUniverse(IUniverseObject sender, IUniverse universe) => base.EnteredUniverse(sender, universe);
-    protected sealed override void ExitedUniverse(IUniverseObject sender, IUniverse universe) => base.ExitedUniverse(sender, universe);
+    protected override void OnInitialize() => Transform = BehaviourController.GetRequiredBehaviour<ITransform2D>();
+    protected override void OnFinalize() => Transform = null!;
 }

Engine.Core/BehaviourBase.cs

@@ -3,9 +3,16 @@ namespace Syntriax.Engine.Core;
 [System.Diagnostics.DebuggerDisplay("{GetType().Name, nq}, Priority: {Priority}, Initialized: {Initialized}")]
 public abstract class BehaviourBase : BaseEntity, IBehaviour
 {
-    public event IHasBehaviourController.BehaviourControllerAssignedEventHandler? OnBehaviourControllerAssigned = null;
-    public event IBehaviour.PriorityChangedEventHandler? OnPriorityChanged = null;
-    public event IActive.ActiveChangedEventHandler? OnActiveChanged = null;
+    public Event<IBehaviour, IBehaviour.PriorityChangedArguments> OnPriorityChanged { get; } = new();
+    public Event<IActive, IActive.ActiveChangedArguments> OnActiveChanged { get; } = new();
+    public Event<IHasBehaviourController> OnBehaviourControllerAssigned { get; } = new();
+
+    private readonly Event<IHasUniverseObject>.EventHandler delegateOnUniverseObjectAssigned = null!;
+    private readonly Event<IActive, IActive.ActiveChangedArguments>.EventHandler delegateOnUniverseObjectActiveChanged = null!;
+    private readonly Event<IStateEnable, IStateEnable.EnabledChangedArguments>.EventHandler delegateOnStateEnabledChanged = null!;
+
+    public IUniverse Universe => BehaviourController.UniverseObject.Universe;
+    public IUniverseObject UniverseObject => BehaviourController.UniverseObject;
 
     private IBehaviourController _behaviourController = null!;
     public IBehaviourController BehaviourController => _behaviourController;
@@ -21,7 +28,7 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
 
             int previousPriority = _priority;
             _priority = value;
-            OnPriorityChanged?.InvokeSafe(this, previousPriority);
+            OnPriorityChanged?.Invoke(this, new(previousPriority));
         }
     }
 
@@ -36,16 +43,17 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
 
         _behaviourController = behaviourController;
         OnAssign(behaviourController);
-        behaviourController.OnUniverseObjectAssigned += OnUniverseObjectAssigned;
+        behaviourController.OnUniverseObjectAssigned.AddListener(delegateOnUniverseObjectAssigned);
+        behaviourController.StateEnable.OnEnabledChanged.AddListener(delegateOnStateEnabledChanged);
         if (behaviourController.UniverseObject is not null)
             OnUniverseObjectAssigned(behaviourController);
-        OnBehaviourControllerAssigned?.InvokeSafe(this);
+        OnBehaviourControllerAssigned?.Invoke(this);
         return true;
     }
 
     private void OnUniverseObjectAssigned(IHasUniverseObject sender)
     {
-        sender.UniverseObject.OnActiveChanged += OnUniverseObjectActiveChanged;
+        sender.UniverseObject.OnActiveChanged.AddListener(delegateOnUniverseObjectActiveChanged);
         UpdateActive();
     }
 
@@ -53,13 +61,15 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
     {
         base.OnAssign(stateEnable);
 
-        stateEnable.OnEnabledChanged += OnStateEnabledChanged;
+        stateEnable.OnEnabledChanged.AddListener(delegateOnStateEnabledChanged);
     }
 
     protected override void UnassignInternal()
     {
-        StateEnable.OnEnabledChanged -= OnStateEnabledChanged;
-        BehaviourController.OnUniverseObjectAssigned -= OnUniverseObjectAssigned;
+        BehaviourController.UniverseObject.OnActiveChanged.RemoveListener(delegateOnUniverseObjectActiveChanged);
+        StateEnable.OnEnabledChanged.RemoveListener(delegateOnStateEnabledChanged);
+        BehaviourController.OnUniverseObjectAssigned.RemoveListener(delegateOnUniverseObjectAssigned);
+        BehaviourController.StateEnable.OnEnabledChanged.RemoveListener(delegateOnStateEnabledChanged);
         base.UnassignInternal();
         _behaviourController = null!;
     }
@@ -68,17 +78,26 @@ public abstract class BehaviourBase : BaseEntity, IBehaviour
     {
         Debug.Assert.AssertBehaviourControllerAssigned(this);
         Debug.Assert.AssertStateEnableAssigned(this);
+
+        UpdateActive();
     }
 
-    private void OnStateEnabledChanged(IStateEnable sender, bool previousState) => UpdateActive();
-    private void OnUniverseObjectActiveChanged(IActive sender, bool previousState) => UpdateActive();
+    private void OnStateEnabledChanged(IStateEnable sender, IStateEnable.EnabledChangedArguments args) => UpdateActive();
+    private void OnUniverseObjectActiveChanged(IActive sender, IActive.ActiveChangedArguments args) => UpdateActive();
 
     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?.InvokeSafe(this, previousActive);
+            OnActiveChanged?.Invoke(this, new(previousActive));
+    }
+
+    protected BehaviourBase()
+    {
+        delegateOnUniverseObjectAssigned = OnUniverseObjectAssigned;
+        delegateOnUniverseObjectActiveChanged = OnUniverseObjectActiveChanged;
+        delegateOnStateEnabledChanged = OnStateEnabledChanged;
     }
 }

Engine.Core/BehaviourCollector.cs

@@ -1,67 +1,69 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
 public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
 {
-    public event IAssignable.UnassignEventHandler? OnUnassigned = null;
-    public event IHasUniverse.UniverseAssignedEventHandler? OnUniverseAssigned = null;
+    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 event IBehaviourCollector<T>.CollectedEventHandler? OnCollected = null;
-    public event IBehaviourCollector<T>.RemovedEventHandler? OnRemoved = null;
+    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 IReadOnlyList<T> Behaviours => behaviours;
     public IUniverse Universe { get; private set; } = null!;
 
-    public T this[Index index] => behaviours[index];
-
-    public BehaviourCollector() { }
-    public BehaviourCollector(IUniverse universe) => Assign(universe);
-
-    private void OnUniverseObjectRegistered(IUniverse manager, IUniverseObject universeObject)
+    private void OnUniverseObjectRegistered(IUniverse manager, IUniverse.UniverseObjectRegisteredArguments args)
     {
-        universeObject.BehaviourController.OnBehaviourAdded += OnBehaviourAdded;
-        universeObject.BehaviourController.OnBehaviourRemoved += OnBehaviourRemoved;
+        IUniverseObject universeObject = args.UniverseObjectRegistered;
 
-        foreach (IBehaviour item in universeObject.BehaviourController)
-            OnBehaviourAdded(universeObject.BehaviourController, item);
+        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, IUniverseObject universeObject)
+    private void OnUniverseObjectUnregistered(IUniverse manager, IUniverse.UniverseObjectUnRegisteredArguments args)
     {
-        universeObject.BehaviourController.OnBehaviourAdded -= OnBehaviourAdded;
-        universeObject.BehaviourController.OnBehaviourRemoved -= OnBehaviourRemoved;
+        IUniverseObject universeObject = args.UniverseObjectUnregistered;
 
-        foreach (IBehaviour item in universeObject.BehaviourController)
-            OnBehaviourRemoved(universeObject.BehaviourController, item);
+        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 AddBehaviour(T behaviour) => behaviours.Add(behaviour);
     protected virtual void OnBehaviourAdd(IBehaviour behaviour) { }
-    private void OnBehaviourAdded(IBehaviourController controller, IBehaviour behaviour)
+    private void OnBehaviourAdded(IBehaviourController controller, IBehaviourController.BehaviourAddedArguments args)
     {
-        if (behaviour is not T tBehaviour)
+        if (args.BehaviourAdded is not T tBehaviour)
             return;
 
-        behaviours.Add(tBehaviour);
-        OnBehaviourAdd(behaviour);
-        OnCollected?.InvokeSafe(this, tBehaviour);
+        AddBehaviour(tBehaviour);
+        OnBehaviourAdd(args.BehaviourAdded);
+        OnCollected?.Invoke(this, new(tBehaviour));
     }
 
     protected virtual void OnBehaviourRemove(IBehaviour behaviour) { }
-    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviour behaviour)
+    private void OnBehaviourRemoved(IBehaviourController controller, IBehaviourController.BehaviourRemovedArguments args)
     {
-        if (behaviour is not T tBehaviour)
+        if (args.BehaviourRemoved is not T tBehaviour)
             return;
 
         if (!behaviours.Remove(tBehaviour))
             return;
 
-        OnBehaviourRemove(behaviour);
-        OnRemoved?.InvokeSafe(this, tBehaviour);
+        OnBehaviourRemove(args.BehaviourRemoved);
+        OnRemoved?.Invoke(this, new(tBehaviour));
     }
 
     protected virtual void OnAssign(IUniverse universe) { }
@@ -71,14 +73,14 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
             return false;
 
         foreach (IUniverseObject universeObject in universe.UniverseObjects)
-            OnUniverseObjectRegistered(universe, universeObject);
+            OnUniverseObjectRegistered(universe, new(universeObject));
 
-        universe.OnUniverseObjectRegistered += OnUniverseObjectRegistered;
-        universe.OnUniverseObjectUnRegistered += OnUniverseObjectUnregistered;
+        universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
+        universe.OnPreUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
 
         Universe = universe;
         OnAssign(universe);
-        OnUniverseAssigned?.InvokeSafe(this);
+        OnUniverseAssigned?.Invoke(this);
 
         return true;
     }
@@ -89,16 +91,34 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
             return false;
 
         foreach (IUniverseObject universeObject in Universe.UniverseObjects)
-            OnUniverseObjectUnregistered(Universe, universeObject);
+            OnUniverseObjectUnregistered(Universe, new(universeObject));
 
-        Universe.OnUniverseObjectRegistered -= OnUniverseObjectRegistered;
-        Universe.OnUniverseObjectUnRegistered -= OnUniverseObjectUnregistered;
+        Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
+        Universe.OnPreUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
 
         Universe = null!;
-        OnUnassigned?.InvokeSafe(this);
+        OnUnassigned?.Invoke(this);
         return true;
     }
 
-    public IEnumerator<T> GetEnumerator() => behaviours.GetEnumerator();
-    IEnumerator IEnumerable.GetEnumerator() => behaviours.GetEnumerator();
+    public int Count => behaviours.Count;
+    public T this[Index index] => behaviours[index];
+
+    public BehaviourCollector()
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+    }
+
+    public BehaviourCollector(IUniverse universe)
+    {
+        delegateOnBehaviourAdded = OnBehaviourAdded;
+        delegateOnBehaviourRemoved = OnBehaviourRemoved;
+        delegateOnUniverseObjectRegistered = OnUniverseObjectRegistered;
+        delegateOnUniverseObjectUnregistered = OnUniverseObjectUnregistered;
+
+        Assign(universe);
+    }
 }

Engine.Core/BehaviourCollectorSorted.cs

@@ -1,11 +1,14 @@
 using System;
+using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
 public class BehaviourCollectorSorted<T> : BehaviourCollector<T> where T : class
 {
-    private Comparison<T>? _sortBy = null;
-    public Comparison<T>? SortBy
+    private readonly Event<IBehaviour, IBehaviour.PriorityChangedArguments>.EventHandler delegateOnPriorityChanged = null!;
+
+    private IComparer<T>? _sortBy = null;
+    public IComparer<T>? SortBy
     {
         get => _sortBy;
         set
@@ -17,12 +20,48 @@ public class BehaviourCollectorSorted<T> : BehaviourCollector<T> where T : class
         }
     }
 
-    protected override void OnBehaviourAdd(IBehaviour behaviour)
+    protected override void AddBehaviour(T behaviour)
     {
-        if (SortBy is not null)
-            behaviours.Sort(SortBy);
+        if (SortBy is null)
+        {
+            behaviours.Add(behaviour);
+            return;
+        }
+
+        int insertionIndex = behaviours.BinarySearch(behaviour, SortBy);
+
+        if (insertionIndex < 0)
+            insertionIndex = ~insertionIndex;
+
+        behaviours.Insert(insertionIndex, behaviour);
     }
 
-    public BehaviourCollectorSorted() { }
-    public BehaviourCollectorSorted(IUniverse universe, Comparison<T> sortBy) : base(universe) => SortBy = sortBy;
+    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

@@ -1,26 +1,22 @@
 using System;
-using System.Collections;
 using System.Collections.Generic;
-using System.Linq;
 
 namespace Syntriax.Engine.Core;
 
 [System.Diagnostics.DebuggerDisplay("Behaviour Count: {behaviours.Count}")]
 public class BehaviourController : BaseEntity, IBehaviourController
 {
-    public event IBehaviourController.PreUpdateEventHandler? OnPreUpdate = null;
-    public event IBehaviourController.UpdateEventHandler? OnUpdate = null;
-    public event IBehaviourController.PreDrawEventHandler? OnPreDraw = null;
+    public Event<IBehaviourController, IBehaviourController.BehaviourAddedArguments> OnBehaviourAdded { get; } = new();
+    public Event<IBehaviourController, IBehaviourController.BehaviourRemovedArguments> OnBehaviourRemoved { get; } = new();
+    public Event<IHasUniverseObject> OnUniverseObjectAssigned { get; } = new();
 
-    public event IBehaviourController.BehaviourAddedEventHandler? OnBehaviourAdded = null;
-    public event IBehaviourController.BehaviourRemovedEventHandler? OnBehaviourRemoved = null;
-    public event IHasUniverseObject.UniverseObjectAssignedEventHandler? OnUniverseObjectAssigned = null;
-
-    private readonly IList<IBehaviour> behaviours = new List<IBehaviour>(Constants.BEHAVIOURS_SIZE_INITIAL);
+    private readonly List<IBehaviour> behaviours = new(Constants.BEHAVIOURS_SIZE_INITIAL);
 
     private IUniverseObject _universeObject = null!;
 
     public IUniverseObject UniverseObject => _universeObject;
+    public int Count => behaviours.Count;
+    public IBehaviour this[Index index] => behaviours[index];
 
     public T AddBehaviour<T>(T behaviour) where T : class, IBehaviour
     {
@@ -30,13 +26,17 @@ public class BehaviourController : BaseEntity, IBehaviourController
 
         if (IsInitialized)
             behaviour.Initialize();
-        behaviour.OnPriorityChanged += OnPriorityChange;
-        OnBehaviourAdded?.InvokeSafe(this, behaviour);
+
+        behaviour.OnPriorityChanged.AddListener(OnPriorityChange);
+        OnBehaviourAdded?.Invoke(this, new(behaviour));
         return behaviour;
     }
 
     public T AddBehaviour<T>(params object?[]? args) where T : class, IBehaviour
-        => AddBehaviour(Factory.BehaviourFactory.Instantiate<T>(_universeObject, args));
+    {
+        T behaviour = Factory.BehaviourFactory.Instantiate<T>(args);
+        return AddBehaviour(behaviour);
+    }
 
     public T? GetBehaviour<T>()
     {
@@ -49,17 +49,13 @@ public class BehaviourController : BaseEntity, IBehaviourController
 
     public IReadOnlyList<T> GetBehaviours<T>()
     {
-        List<T>? behaviours = null;
+        List<T> behaviours = [];
+
         foreach (IBehaviour behaviourItem in this.behaviours)
-        {
-            if (behaviourItem is not T behaviour)
-                continue;
+            if (behaviourItem is T behaviour)
+                behaviours.Add(behaviour);
 
-            behaviours ??= [];
-            behaviours.Add(behaviour);
-        }
-
-        return behaviours ?? Enumerable.Empty<T>().ToList();
+        return behaviours;
     }
 
     public void GetBehaviours<T>(IList<T> results)
@@ -76,7 +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;
@@ -93,10 +89,10 @@ public class BehaviourController : BaseEntity, IBehaviourController
         if (!behaviours.Contains(behaviour))
             throw new Exception($"{behaviour.GetType().Name} does not exist in {UniverseObject.Name}'s {nameof(IBehaviourController)}.");
 
-        behaviour.OnPriorityChanged -= OnPriorityChange;
+        behaviour.OnPriorityChanged.RemoveListener(OnPriorityChange);
         behaviour.Finalize();
         behaviours.Remove(behaviour);
-        OnBehaviourRemoved?.InvokeSafe(this, behaviour);
+        OnBehaviourRemoved?.Invoke(this, new(behaviour));
     }
 
     protected virtual void OnAssign(IUniverseObject universeObject) { }
@@ -107,7 +103,7 @@ public class BehaviourController : BaseEntity, IBehaviourController
 
         _universeObject = universeObject;
         OnAssign(universeObject);
-        OnUniverseObjectAssigned?.InvokeSafe(this);
+        OnUniverseObjectAssigned?.Invoke(this);
         return true;
     }
 
@@ -125,27 +121,6 @@ public class BehaviourController : BaseEntity, IBehaviourController
             behaviour.Finalize();
     }
 
-    public void Update()
-    {
-        Debug.Assert.AssertInitialized(this);
-
-        if (!UniverseObject.StateEnable.Enabled || !StateEnable.Enabled)
-            return;
-
-        OnPreUpdate?.InvokeSafe(this);
-        OnUpdate?.InvokeSafe(this);
-    }
-
-    public void UpdatePreDraw()
-    {
-        Debug.Assert.AssertInitialized(this);
-
-        if (!UniverseObject.StateEnable.Enabled || !StateEnable.Enabled)
-            return;
-
-        OnPreDraw?.InvokeSafe(this);
-    }
-
     public BehaviourController() { }
     public BehaviourController(IUniverseObject universeObject) => Assign(universeObject);
 
@@ -166,12 +141,9 @@ public class BehaviourController : BaseEntity, IBehaviourController
             behaviours.Add(behaviour);
     }
 
-    private void OnPriorityChange(IBehaviour sender, int previousPriority)
+    private void OnPriorityChange(IBehaviour sender, IBehaviour.PriorityChangedArguments args)
     {
         behaviours.Remove(sender);
         InsertBehaviourByPriority(sender);
     }
-
-    public IEnumerator<IBehaviour> GetEnumerator() => behaviours.GetEnumerator();
-    IEnumerator IEnumerable.GetEnumerator() => behaviours.GetEnumerator();
 }

Engine.Core/CoroutineManager.cs

@@ -3,7 +3,7 @@ using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
-public class CoroutineManager : UniverseObject
+public class CoroutineManager : Behaviour, IUpdate
 {
     private readonly List<IEnumerator> enumerators = [];
 
@@ -18,17 +18,7 @@ public class CoroutineManager : UniverseObject
         enumerators.Remove(enumerator);
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
-    {
-        universe.OnUpdate += OnUpdate;
-    }
-
-    protected override void OnExitingUniverse(IUniverse universe)
-    {
-        universe.OnUpdate -= OnUpdate;
-    }
-
-    private void OnUpdate(IUniverse sender, UniverseTime time)
+    void IUpdate.Update()
     {
         for (int i = enumerators.Count - 1; i >= 0; i--)
         {
@@ -39,4 +29,6 @@ public class CoroutineManager : UniverseObject
                 enumerators.RemoveAt(i);
         }
     }
+
+    public CoroutineManager() => Priority = int.MinValue;
 }

Engine.Core/Debug/AssertHelpers.cs

@@ -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/FileLogger.cs

@@ -7,14 +7,23 @@ public class FileLogger : LoggerBase
 {
     public readonly string FilePath;
 
-    public FileLogger(string filePath)
-    {
-        FilePath = filePath;
-        File.Open(filePath, FileMode.Create).Close();
-    }
-
     protected override void Write(string message)
     {
         File.AppendAllTextAsync(FilePath, $"{message}{Environment.NewLine}");
     }
+
+    public FileLogger(string filePath)
+    {
+        FilePath = filePath;
+
+        bool isRelativePath = Path.GetFullPath(filePath).CompareTo(filePath) != 0;
+
+        if (isRelativePath)
+            FilePath = Path.GetFullPath(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, filePath));
+
+        if (Path.GetDirectoryName(FilePath) is string directoryPath)
+            Directory.CreateDirectory(directoryPath);
+
+        File.Open(FilePath, FileMode.Create).Close();
+    }
 }

Engine.Core/Debug/ILogger.cs

@@ -2,12 +2,15 @@ namespace Syntriax.Engine.Core.Debug;
 
 public interface ILogger
 {
+    static ILogger Shared { get; set; } = new ConsoleLogger();
+
     Level FilterLevel { get; set; }
 
     void Log(string message, Level level = Level.Info, bool force = false);
 
     enum Level
     {
+        Trace,
         Info,
         Warning,
         Error,

Engine.Core/Debug/LoggerBase.cs

@@ -4,7 +4,7 @@ namespace Syntriax.Engine.Core.Debug;
 
 public abstract class LoggerBase : ILogger
 {
-    public ILogger.Level FilterLevel { get; set; } = ILogger.Level.Info;
+    public ILogger.Level FilterLevel { get; set; } = ILogger.Level.Trace;
 
     public void Log(string message, ILogger.Level level = ILogger.Level.Info, bool force = false)
     {

Engine.Core/Debug/LoggerContainer.cs

@@ -0,0 +1,9 @@
+namespace Syntriax.Engine.Core.Debug;
+
+public class LoggerContainer : Behaviour, ILogger
+{
+    public ILogger Logger { get; set; } = ILogger.Shared;
+
+    public ILogger.Level FilterLevel { get => Logger.FilterLevel; set => Logger.FilterLevel = value; }
+    public void Log(string message, ILogger.Level level = ILogger.Level.Info, bool force = false) => Logger.Log(message, level, force);
+}

Engine.Core/Debug/LoggerExtensions.cs

@@ -16,13 +16,21 @@ public static class LoggerExtensions
     public static void LogError<T>(this ILogger logger, T caller, string message, bool force = false)
     {
         Log(logger, caller, message, ILogger.Level.Error, force);
-        Log(logger, caller, $"{nameof(StackTrace)}:{Environment.NewLine}{new StackTrace()}");
+        LogTrace(logger, caller, new StackTrace(), force);
     }
 
     public static void LogException<T>(this ILogger logger, T caller, Exception exception, bool force = false)
     {
+        Log(logger, caller, $"Exception of type {exception.GetType().Name} occured", ILogger.Level.Error, force);
         Log(logger, caller, $"Message: {exception.Message}", ILogger.Level.Error, force);
         Log(logger, caller, $"InnerException: {exception.InnerException}", ILogger.Level.Error, force);
-        Log(logger, caller, $"{nameof(StackTrace)}:{Environment.NewLine}{exception.StackTrace}");
+
+        // Not using LogTrace because exception.StackTrace is a type of string
+        Log(logger, caller, $"{nameof(StackTrace)}:{Environment.NewLine}{exception.StackTrace}", ILogger.Level.Trace);
+    }
+
+    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

@@ -0,0 +1,23 @@
+namespace Syntriax.Engine.Core.Debug;
+
+public class LoggerWrapper(ILogger firstLogger, ILogger secondLogger) : ILogger
+{
+    private readonly ILogger firstLogger = firstLogger;
+    private readonly ILogger secondLogger = secondLogger;
+
+    public ILogger.Level FilterLevel
+    {
+        get => firstLogger.FilterLevel;
+        set
+        {
+            firstLogger.FilterLevel = value;
+            secondLogger.FilterLevel = value;
+        }
+    }
+
+    public void Log(string message, ILogger.Level level = ILogger.Level.Info, bool force = false)
+    {
+        firstLogger.Log(message, level, force);
+        secondLogger.Log(message, level, force);
+    }
+}

Engine.Core/Debug/LoggerWrapperExtensions.cs

@@ -0,0 +1,6 @@
+namespace Syntriax.Engine.Core.Debug;
+
+public static class LoggerWrapperExtensions
+{
+    public static ILogger WrapWith(this ILogger thisLogger, ILogger logger) => new LoggerWrapper(thisLogger, logger);
+}

Engine.Core/Engine.Core.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>false</ImplicitUsings>
     <Nullable>enable</Nullable>
     <RootNamespace>Syntriax.Engine.Core</RootNamespace>

Engine.Core/Exceptions/BehaviourNotFoundException.cs

@@ -1,9 +1,3 @@
-using System;
-
 namespace Syntriax.Engine.Core.Exceptions;
 
-public class BehaviourNotFoundException(string? message) : Exception(message)
-{
-    public static NotAssignedException FromType<TBehaviour>()
-        => new($"{typeof(TBehaviour).FullName} was not found");
-}
+public class BehaviourNotFoundException(string? message) : NotFoundException(message);

Engine.Core/Exceptions/NotFoundException.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace Syntriax.Engine.Core.Exceptions;
+
+public class NotFoundException(string? message) : Exception(message)
+{
+    public static NotAssignedException FromType<T>()
+        => new($"{typeof(T).FullName} was not found");
+}

Engine.Core/Exceptions/UniverseObjectNotFoundException.cs

@@ -1,9 +1,3 @@
-using System;
-
 namespace Syntriax.Engine.Core.Exceptions;
 
-public class UniverseObjectNotFoundException(string? message) : Exception(message)
-{
-    public static NotAssignedException FromType<TUniverseObject>()
-        => new($"{typeof(TUniverseObject).FullName} was not found");
-}
+public class UniverseObjectNotFoundException(string? message) : NotFoundException(message);

Engine.Core/Extensions/BehaviourControllerExtensions.cs

@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
 using Syntriax.Engine.Core.Exceptions;
@@ -26,7 +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.
@@ -38,6 +39,19 @@ public static class BehaviourControllerExtensions
     public static T GetOrAddBehaviour<T>(this IBehaviourController behaviourController, params object?[]? args) where T : class, IBehaviour
         => behaviourController.GetBehaviour<T>() ?? behaviourController.AddBehaviour<T>(args);
 
+    /// <summary>
+    /// Gets an existing <see cref="IBehaviour"/> of the specified type, or adds and returns the fallback type if it doesn't exist.
+    /// </summary>
+    /// <typeparam name="TOriginal">The type of <see cref="IBehaviour"/> to get.</typeparam>
+    /// <typeparam name="TFallback">The type of <see cref="IBehaviour"/> to add. It must be assignable from <typeparamref name="TOriginal"/></typeparam>
+    /// <param name="behaviourController">The <see cref="IBehaviourController"/> to search in.</param>
+    /// <param name="args">Optional arguments to pass to the constructor of the <see cref="IBehaviour"/> if a new one is added.</param>
+    /// <returns>The existing or newly added <see cref="IBehaviour"/> of the specified type.</returns>
+    public static TOriginal GetOrAddBehaviour<TOriginal, TFallback>(this IBehaviourController behaviourController, params object?[]? args)
+            where TOriginal : class
+            where TFallback : class, IBehaviour, TOriginal
+        => behaviourController.GetBehaviour<TOriginal>() ?? behaviourController.AddBehaviour<TFallback>(args);
+
     /// <summary>
     /// Tries to get a <see cref="IBehaviour"/> of the specified type in it's <see cref="IUniverseObject"/>'s parents recursively.
     /// </summary>
@@ -79,7 +93,28 @@ 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.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/>s to get.</typeparam>
+    /// <param name="behavioursInParent">The list to store the <see cref="IBehaviour"/>s.</param>
+    public static void GetBehavioursInParent<T>(this IBehaviourController behaviourController, IList<T> behavioursInParent) where T : class
+    {
+        IBehaviourController? controller = behaviourController;
+        List<T> cache = [];
+        behavioursInParent.Clear();
+
+        while (controller is not null)
+        {
+            controller.GetBehaviours(cache);
+            foreach (T behaviour in cache)
+                behavioursInParent.Add(behaviour);
+
+            controller = controller.UniverseObject.Parent?.BehaviourController;
+        }
+    }
 
     /// <summary>
     /// Tries to get a <see cref="IBehaviour"/> of the specified type in it's <see cref="IUniverseObject"/>'s children recursively.
@@ -105,7 +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;
 
@@ -119,5 +154,29 @@ 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.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/>s to get.</typeparam>
+    /// <param name="behavioursInChildren">The list to store the <see cref="IBehaviour"/>s.</param>
+    public static void GetBehavioursInChildren<T>(this IBehaviourController behaviourController, IList<T> behavioursInChildren) where T : class
+    {
+        List<T> cache = [];
+        behavioursInChildren.Clear();
+
+        TraverseChildrenForBehaviour(behaviourController.UniverseObject, behavioursInChildren, cache);
+    }
+
+    private static void TraverseChildrenForBehaviour<T>(IUniverseObject universeObject, IList<T> behaviours, IList<T> cache) where T : class
+    {
+        universeObject.BehaviourController.GetBehaviours(cache);
+
+        foreach (T behaviour in cache)
+            behaviours.Add(behaviour);
+
+        foreach (IUniverseObject child in universeObject.Children)
+            TraverseChildrenForBehaviour(child, behaviours, cache);
+    }
 }

Engine.Core/Extensions/BehaviourExtensions.cs

@@ -1,34 +0,0 @@
-using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
-
-namespace Syntriax.Engine.Core;
-
-public static class BehaviourExtensions
-{
-    public static T? FindBehaviour<T>(this IEnumerable<IUniverseObject> universeObjects) where T : class
-    {
-        foreach (IUniverseObject universeObject in universeObjects)
-            if (universeObject.BehaviourController.GetBehaviour<T>() is T behaviour)
-                return behaviour;
-
-        return default;
-    }
-
-    public static bool TryFindBehaviour<T>(this IEnumerable<IUniverseObject> universeObjects, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
-    {
-        behaviour = FindBehaviour<T>(universeObjects);
-        return behaviour is not null;
-    }
-
-    public static void FindBehaviours<T>(this IEnumerable<IUniverseObject> universeObjects, List<T> behaviours) where T : class
-    {
-        behaviours.Clear();
-        List<T> cache = [];
-
-        foreach (IUniverseObject universeObject in universeObjects)
-        {
-            universeObject.BehaviourController.GetBehaviours(cache);
-            behaviours.AddRange(cache);
-        }
-    }
-}

Engine.Core/Extensions/UniverseExtensions.cs

@@ -7,9 +7,30 @@ public static class UniverseExtensions
     public static IUniverseObject InstantiateUniverseObject(this IUniverse universe, params object?[]? args)
         => universe.InstantiateUniverseObject<UniverseObject>(args);
 
+    /// <summary>
+    /// Searches through all <see cref="IUniverseObject"/>s to find the specified instance of the type.
+    /// </summary>
+    /// <typeparam name="T">Type to be searched through the <see cref="IUniverse"/>.</typeparam>
+    /// <returns>The specified type if found; otherwise, throws <see cref="UniverseObjectNotFoundException"/>.</returns>
     public static T GetRequiredUniverseObject<T>(this IUniverse universe) where T : class
         => universe.GetUniverseObject<T>() ?? throw new UniverseObjectNotFoundException($"{universe.GetType().FullName}({universe.Id}) does not contain any {nameof(IUniverseObject)} object of type {typeof(T).FullName}");
 
+    /// <summary>
+    /// Searches through all <see cref="IBehaviours"/>s to find the specified instance of the type.
+    /// </summary>
+    /// <typeparam name="T">Type to be searched through the <see cref="IUniverse"/>.</typeparam>
+    /// <returns>The specified type if found; otherwise, throws <see cref="BehaviourNotFoundException"/>.</returns>
     public static T FindRequiredBehaviour<T>(this IUniverse universe) where T : class
         => universe.FindBehaviour<T>() ?? throw new BehaviourNotFoundException($"{universe.GetType().FullName}({universe.Id}) does not contain any {nameof(IUniverseObject)} with {nameof(IBehaviour)} of type {typeof(T).FullName}");
+
+    /// <summary>
+    /// Searches through all <see cref="IUniverseObject"/>s and <see cref="IBehaviours"/>s to find the specified instance of the type.
+    /// </summary>
+    /// <remarks>
+    /// WARNING: This is more expensive compared to <see cref="GetRequiredUniverseObject{T}(IUniverse)"/> or <see cref="FindRequiredBehaviour{T}(IUniverse)"/> as it combines the two. If you know whether the type is either a type that gets implemented on an <see cref="IBehaviour"/> or <see cref="IUniverseObject"/> use the method appropriate for it for performance.
+    /// </remarks>
+    /// <typeparam name="T">Type to be searched through the <see cref="IUniverse"/>.</typeparam>
+    /// <returns>The specified type if found; otherwise, throws <see cref="NotFoundException"/>.</returns>
+    public static T FindRequired<T>(this IUniverse universe) where T : class
+        => universe.Find<T>() ?? throw new NotFoundException($"{universe.GetType().FullName}({universe.Id}) does not contain any {nameof(IUniverseObject)} or {nameof(IBehaviour)} of type {typeof(T).FullName}");
 }

Engine.Core/Extensions/UniverseObjectExtensions.cs

@@ -1,6 +1,8 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
+using Syntriax.Engine.Core.Exceptions;
+
 namespace Syntriax.Engine.Core;
 
 public static class UniverseObjectExtensions
@@ -10,10 +12,17 @@ public static class UniverseObjectExtensions
         if (!string.IsNullOrWhiteSpace(name))
             universeObject.Name = name;
         if (parent is not null)
-            universeObject.SetParent(parent);
+            universeObject.Parent = parent;
         return universeObject;
     }
 
+    #region Universe Object Search
+    /// <summary>
+    /// Gets a <see cref="IUniverseObject"/> of the specified type.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObjects">The <see cref="IUniverseObject"/>s to search.</param>
+    /// <returns>The first found <see cref="IUniverseObject"/> of the specified type; otherwise, null.</returns>
     public static T? GetUniverseObject<T>(this IEnumerable<IUniverseObject> universeObjects) where T : class
     {
         foreach (IUniverseObject universeObject in universeObjects)
@@ -23,17 +32,224 @@ public static class UniverseObjectExtensions
         return default;
     }
 
-    public static bool TryGetUniverseObject<T>(this IEnumerable<IUniverseObject> universeObjects, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
+    /// <summary>
+    /// Tries to get a <see cref="IUniverseObject"/> of the specified type.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObjects">The <see cref="IUniverseObject"/>s to search.</param>
+    /// <returns><see cref="true"/> if a <see cref="IUniverseObject"/> of the specified type was found in the universe objects; otherwise, <see cref="false"/>.</returns>
+    public static bool TryGetUniverseObject<T>(this IEnumerable<IUniverseObject> universeObjects, [NotNullWhen(returnValue: true)] out T? universeObject) where T : class
     {
-        behaviour = GetUniverseObject<T>(universeObjects);
+        universeObject = GetUniverseObject<T>(universeObjects);
+        return universeObject is not null;
+    }
+
+    /// <summary>
+    /// Searches through the provided <see cref="IUniverseObject"/>s to collect a list of <see cref="IUniverseObject"/>s of the specified type.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObject">The <see cref="IUniverseObject"/> to search.</param>
+    /// <returns>The found <see cref="IUniverseObject"/>s of the specified types</returns>
+    public static void GetUniverseObjects<T>(this IEnumerable<IUniverseObject> universeObjects, IList<T> foundUniverseObjects) where T : class
+    {
+        foundUniverseObjects.Clear();
+
+        foreach (IUniverseObject universeObject in universeObjects)
+            if (universeObject is T @object)
+                foundUniverseObjects.Add(@object);
+    }
+    #endregion
+
+    #region Universe Object Search In Parent
+    /// <summary>
+    /// Tries to get a <see cref="IUniverseObject"/> of the specified type in it's parents recursively.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="behaviour">When this method returns, contains the <see cref="IUniverseObject"/> of the specified type, if found; otherwise, null.</param>
+    /// <returns><see cref="true"/> if a <see cref="IUniverseObject"/> of the specified type was found in the parent universe objects; otherwise, <see cref="false"/>.</returns>
+    public static bool TryGetUniverseObjectInParent<T>(this IUniverseObject universeObject, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
+    {
+        behaviour = GetUniverseObjectInParent<T>(universeObject);
         return behaviour is not null;
     }
 
-    public static void GetUniverseObjects<T>(this IEnumerable<IUniverseObject> universeObjects, List<T> behaviours) where T : class
+    /// <summary>
+    /// Gets a <see cref="IUniverseObject"/> of the specified type in it's parents recursively.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObject">The <see cref="IUniverseObject"/> to start searching from.</param>
+    /// <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.Children.GetUniverseObject<T>() is T localUniverseObject)
+            return localUniverseObject;
+
+        IUniverseObject? parent = universeObject;
+
+        while (parent is not null)
+        {
+            if (parent is T behaviour)
+                return behaviour;
+
+            parent = universeObject.Parent;
+        }
+
+        return default;
+    }
+
+    /// <summary>
+    /// Gets a <see cref="IUniverseObject"/> of the specified type in the parents recursively. Throws an error if not found.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObject">The <see cref="IUniverseObject"/> to start searching from.</param>
+    /// <returns>The <see cref="IUniverseObject"/> of the specified type if found; otherwise, throws <see cref="UniverseObjectNotFoundException"/>.</returns>
+    public static T GetRequiredUniverseObjectInParent<T>(this IUniverseObject universeObject) where T : class
+        => universeObject.GetUniverseObjectInParent<T>() ?? throw new UniverseObjectNotFoundException($"{universeObject.Name}'s {nameof(IUniverseObject)} does not contain any {typeof(T).FullName} on any parent ");
+
+    #endregion
+
+    #region Universe Object Search In Children
+    /// <summary>
+    /// Tries to get a <see cref="IUniverseObject"/> of the specified type in it's children recursively.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="behaviour">When this method returns, contains the <see cref="IUniverseObject"/> of the specified type, if found; otherwise, null.</param>
+    /// <returns><see cref="true"/> if a <see cref="IUniverseObject"/> of the specified type was found in the child universe objects; otherwise, <see cref="false"/>.</returns>
+    public static bool TryGetUniverseObjectInChildren<T>(this IUniverseObject universeObject, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
+    {
+        behaviour = GetUniverseObjectInChildren<T>(universeObject);
+        return behaviour is not null;
+    }
+
+    /// <summary>
+    /// Gets a <see cref="IUniverseObject"/> of the specified type in it's children recursively.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObject">The <see cref="IUniverseObject"/> to start searching from.</param>
+    /// <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.Children.GetUniverseObject<T>() is T localUniverseObject)
+            return localUniverseObject;
+
+        foreach (IUniverseObject child in universeObject.Children)
+            if (GetUniverseObjectInChildren<T>(child) is T behaviour)
+                return behaviour;
+
+        return default;
+    }
+
+    /// <summary>
+    /// Gets a <see cref="IUniverseObject"/> of the specified type in the children recursively. Throws an error if not found.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IUniverseObject"/> to get.</typeparam>
+    /// <param name="universeObject">The <see cref="IUniverseObject"/> to start searching from.</param>
+    /// <returns>The <see cref="IUniverseObject"/> of the specified type if found; otherwise, throws <see cref="UniverseObjectNotFoundException"/>.</returns>
+    public static T GetRequiredUniverseObjectInChildren<T>(this IUniverseObject universeObject) where T : class
+        => universeObject.GetUniverseObjectInChildren<T>() ?? throw new UniverseObjectNotFoundException($"{universeObject.Name}'s {nameof(IUniverseObject)} does not contain any {typeof(T).FullName} on any children ");
+    #endregion
+
+    #region Behaviour Search
+    /// <summary>
+    /// Finds a <see cref="IBehaviour"/> of the specified type in the provided <see cref="IUniverseObject"/>s.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to find.</typeparam>
+    /// <returns>The first found <see cref="IBehaviour"/> of the specified type; otherwise, null.</returns>
+    public static T? FindBehaviour<T>(this IEnumerable<IUniverseObject> universeObjects) where T : class
+    {
+        foreach (IUniverseObject universeObject in universeObjects)
+            if (universeObject.BehaviourController.GetBehaviour<T>() is T behaviour)
+                return behaviour;
+
+        return default;
+    }
+
+    /// <summary>
+    /// Tries to find a <see cref="IBehaviour"/> of the specified type in the provided <see cref="IUniverseObject"/>s.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to find.</typeparam>
+    /// <param name="behaviour">When this method returns, contains the <see cref="IUniverseObject"/> of the specified type, if found; otherwise, null.</param>
+    /// <returns><see cref="true"/> if a <see cref="IBehaviour"/> of the specified type was found in the provided <see cref="IUniverseObject"/>s; otherwise, <see cref="false"/>.</returns>
+    public static bool TryFindBehaviour<T>(this IEnumerable<IUniverseObject> universeObjects, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
+    {
+        behaviour = FindBehaviour<T>(universeObjects);
+        return behaviour is not null;
+    }
+
+    /// <summary>
+    /// Searches through the provided <see cref="IUniverseObject"/>s to collect a list of <see cref="IBehaviour"/>s of the specified type.
+    /// </summary>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to get.</typeparam>
+    /// <param name="universeObjects">The <see cref="IUniverseObject"/>s to search.</param>
+    public static void FindBehaviours<T>(this IEnumerable<IUniverseObject> universeObjects, IList<T> behaviours) where T : class
     {
         behaviours.Clear();
+        List<T> cache = [];
+
         foreach (IUniverseObject universeObject in universeObjects)
-            if (universeObject is T @object)
-                behaviours.Add(@object);
+        {
+            universeObject.BehaviourController.GetBehaviours(cache);
+            foreach (T behaviour in cache)
+                behaviours.Add(behaviour);
+        }
     }
+    #endregion
+
+    #region General Search
+    /// <summary>
+    /// Finds an object of the specified type in the provided <see cref="IUniverseObject"/>s and their <see cref="IBehaviour"/>s.
+    /// </summary>
+    /// <remarks>
+    /// WARNING: This is more expensive compared to <see cref="GetUniverseObject{T}(IEnumerable{IUniverseObject})"/> or <see cref="FindBehaviour{T}(IEnumerable{IUniverseObject})"/> as it combines the two. If you know whether the type is either a type that gets implemented on an <see cref="IBehaviour"/> or <see cref="IUniverseObject"/> use the method appropriate for it for performance.
+    /// </remarks>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to find.</typeparam>
+    /// <returns>The first found instance of the specified type; otherwise, null.</returns>
+    public static T? Find<T>(this IEnumerable<IUniverseObject> universeObjects) where T : class
+    {
+        if (universeObjects.GetUniverseObject<T>() is T foundUniverseObject)
+            return foundUniverseObject;
+
+        if (universeObjects.FindBehaviour<T>() is T foundBehaviour)
+            return foundBehaviour;
+
+        return null;
+    }
+
+    /// <summary>
+    /// Tries to find an object of the specified type in the provided <see cref="IUniverseObject"/>s and their <see cref="IBehaviour"/>s.
+    /// </summary>
+    /// <remarks>
+    /// WARNING: This is more expensive compared to <see cref="TryGetUniverseObject{T}(IEnumerable{IUniverseObject}, out T?)"/> or <see cref="TryFindBehaviour{T}(IEnumerable{IUniverseObject}, out T?)"/> as it combines the two. If you know whether the type is either a type that gets implemented on an <see cref="IBehaviour"/> or <see cref="IUniverseObject"/> use the method appropriate for it for performance.
+    /// </remarks>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to find.</typeparam>
+    /// <param name="behaviour">When this method returns, contains the <see cref="IUniverseObject"/> of the specified type, if found; otherwise, null.</param>
+    /// <returns><see cref="true"/> if an object of the specified type was found in the provided <see cref="IUniverseObject"/>s; otherwise, <see cref="false"/>.</returns>
+    public static bool TryFind<T>(this IEnumerable<IUniverseObject> universeObjects, [NotNullWhen(returnValue: true)] out T? behaviour) where T : class
+    {
+        behaviour = Find<T>(universeObjects);
+        return behaviour is not null;
+    }
+
+    /// <summary>
+    /// Searches through the provided <see cref="IUniverseObject"/>s and their <see cref="IBehaviour"/>s to collect a list of the specified type.
+    /// </summary>
+    /// <remarks>
+    /// WARNING: This is more expensive compared to <see cref="GetUniverseObjects{T}(IEnumerable{IUniverseObject}, IList{T})"/> or <see cref="FindBehaviours{T}(IEnumerable{IUniverseObject}, IList{T})"/> as it combines the two. If you know whether the type is either a type that gets implemented on an <see cref="IBehaviour"/> or <see cref="IUniverseObject"/> use the method appropriate for it for performance.
+    /// </remarks>
+    /// <typeparam name="T">The type of <see cref="IBehaviour"/> to get.</typeparam>
+    /// <param name="instances">List of objects found wit the specified type.</param>
+    /// <param name="universeObjects">The <see cref="IUniverseObject"/>s to search.</param>
+    public static void Find<T>(this IEnumerable<IUniverseObject> universeObjects, IList<T> instances) where T : class
+    {
+        instances.Clear();
+        List<T> cache = [];
+
+        foreach (IUniverseObject universeObject in universeObjects)
+        {
+            universeObject.Children.Find(cache);
+            foreach (T behaviour in cache)
+                instances.Add(behaviour);
+        }
+    }
+    #endregion
 }

Engine.Core/Factory/BehaviourControllerFactory.cs

@@ -4,10 +4,10 @@ namespace Syntriax.Engine.Core.Factory;
 
 public class BehaviourControllerFactory
 {
-    public static IBehaviourController Instantiate(IUniverseObject universeObject)
-        => Instantiate<BehaviourController>(universeObject);
+    public static IBehaviourController Instantiate(IUniverseObject universeObject, IStateEnable? stateEnable = null)
+        => 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

@@ -4,22 +4,23 @@ namespace Syntriax.Engine.Core.Factory;
 
 public class BehaviourFactory
 {
-    public static T Instantiate<T>(IUniverseObject universeObject, params object?[]? args) where T : class, IBehaviour
-        => Instantiate<T>(universeObject, stateEnable: null, args);
+    public static T Instantiate<T>(params object?[]? args) where T : class, IBehaviour
+        => Instantiate<T>(stateEnable: null, args);
 
-    public static T Instantiate<T>(IUniverseObject universeObject, IStateEnable? stateEnable, params object?[]? args)
+    public static T Instantiate<T>(IStateEnable? stateEnable, params object?[]? args)
         where T : class, IBehaviour
     {
         T behaviour = TypeFactory.Get<T>(args);
 
-        stateEnable ??= TypeFactory.Get<StateEnable>();
-        if (!stateEnable.Assign(behaviour))
-            throw AssignFailedException.From(stateEnable, behaviour);
-
-        if (!behaviour.Assign(stateEnable))
-            throw AssignFailedException.From(behaviour, stateEnable);
-        if (!behaviour.Assign(universeObject.BehaviourController))
-            throw AssignFailedException.From(behaviour, universeObject.BehaviourController);
+        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/UniverseObjectFactory.cs

@@ -18,18 +18,25 @@ public class UniverseObjectFactory
     {
         T universeObject = TypeFactory.Get<T>(args);
 
-        behaviourController ??= TypeFactory.Get<BehaviourController>();
-        stateEnable ??= TypeFactory.Get<StateEnable>();
+        if (behaviourController is not null)
+        {
+            if (!behaviourController.Assign(universeObject))
+                throw AssignFailedException.From(behaviourController, universeObject);
+            if (!universeObject.Assign(behaviourController))
+                throw AssignFailedException.From(universeObject, behaviourController);
+        }
+        else
+            BehaviourControllerFactory.Instantiate(universeObject);
 
-        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);
-        if (!universeObject.Assign(stateEnable))
-            throw AssignFailedException.From(universeObject, stateEnable);
+        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/DelegateExtensions.cs

@@ -1,17 +0,0 @@
-using System;
-
-namespace Syntriax.Engine.Core;
-
-public static class DelegateExtensions
-{
-    public static void InvokeSafe(this Delegate @delegate, params object?[] args)
-    {
-        foreach (Delegate invocation in @delegate.GetInvocationList())
-            try { invocation.DynamicInvoke(args); }
-            catch (Exception exception)
-            {
-                string methodCallRepresentation = $"{invocation.Method.DeclaringType?.FullName}.{invocation.Method.Name}({string.Join(", ", args)})";
-                Console.WriteLine($"Unexpected exception on invocation of method {methodCallRepresentation}:{Environment.NewLine}{exception.InnerException}");
-            }
-    }
-}

Engine.Core/Helpers/Event.cs

@@ -0,0 +1,500 @@
+using System;
+using System.Collections.Generic;
+
+using Syntriax.Engine.Core.Debug;
+
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a simple event with no parameters.
+/// <para>Example usage:</para> 
+/// <code>
+/// public class MyBehaviour : Behaviour, IUpdate
+/// {
+///     public readonly Event MyEvent = new();
+/// 
+///     public MyBehaviour()
+///     {
+///         MyEvent.AddListener(OnEventTriggered);
+///         MyEvent.AddOneTimeListener(OnEventTriggeredOneTime);
+///     }
+/// 
+///     public void Update()
+///     {
+///         MyEvent.Invoke();
+///     }
+/// 
+///     private void OnEventTriggered()
+///     {
+///         Console.WriteLine($"Event occurred!");
+///     }
+/// 
+///     private static void OnEventTriggeredOneTime()
+///     {
+///         Console.WriteLine($"Event called once!");
+///     }
+/// }
+/// </code>
+/// The output of the example code above would be: 
+/// <code>
+/// Event occurred!
+/// Event called once!
+/// Event occurred!
+/// Event occurred!
+/// Event occurred!
+/// ...
+/// </code>
+/// </summary>
+public class Event
+{
+    // We use Ascending order because draw calls are running from last to first
+    private static readonly Comparer<ListenerData> SortByAscendingPriority = Comparer<ListenerData>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private ILogger _logger = ILogger.Shared;
+    public ILogger Logger { get => _logger; set => _logger = value ?? ILogger.Shared; }
+
+    private readonly List<ListenerData> listeners = null!;
+    private readonly List<ListenerData> onceListeners = null!;
+
+    /// <summary>
+    /// Subscribes the callback to be invoked whenever the event is triggered.
+    /// </summary>
+    /// <param name="listener">The callback to be called when the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = listeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        listeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Subscribes the callback to be invoked the next time the event is triggered. The callback will be called only once.
+    /// </summary>
+    /// <param name="listener">The callback to be called the next time the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddOneTimeListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = onceListeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        onceListeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddListener(EventHandler)"/></param>
+    public void RemoveListener(EventHandler listener)
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            if (listeners[i].Callback == listener)
+            {
+                listeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/></param>
+    public void RemoveOneTimeListener(EventHandler listener)
+    {
+        for (int i = 0; i < onceListeners.Count; i++)
+            if (onceListeners[i].Callback == listener)
+            {
+                onceListeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes all listeners that was previously registered by either <see cref="AddListener(EventHandler)"/> or <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    public void Clear() { listeners.Clear(); onceListeners.Clear(); }
+
+    /// <summary>
+    /// Triggers the event.
+    /// </summary>
+    public void Invoke()
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            try { listeners[i].Callback.Invoke(); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{listeners[i].Callback.Method.DeclaringType?.FullName}.{listeners[i].Callback.Method.Name}()";
+                EventHelpers.LogInvocationException(listeners[i].Callback.Target ?? this, Logger, exception, methodCallRepresentation);
+            }
+
+        for (int i = onceListeners.Count - 1; i >= 0; i--)
+        {
+            try { onceListeners[i].Callback.Invoke(); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{onceListeners[i].Callback.Method.DeclaringType?.FullName}.{onceListeners[i].Callback.Method.Name}()";
+                EventHelpers.LogInvocationException(onceListeners[i].Callback.Target ?? this, Logger, exception, methodCallRepresentation);
+            }
+            onceListeners.RemoveAt(i);
+        }
+    }
+
+    public Event(int initialListenerCount = 4, int initialOnceListenerCount = 2)
+    {
+        listeners = new(initialListenerCount);
+        onceListeners = new(initialOnceListenerCount);
+    }
+
+    public Event()
+    {
+        listeners = new(4);
+        onceListeners = new(2);
+    }
+
+    public delegate void EventHandler();
+    private record struct ListenerData(EventHandler Callback, int Priority);
+}
+
+/// <summary>
+/// Represents an event with only sender parameters.
+/// <para>Example usage:</para> 
+/// <code>
+/// public class MyBehaviour : Behaviour, IUpdate
+/// {
+///     public readonly Event&lt;MyBehaviour&gt; MyEvent = new();
+/// 
+///     public MyBehaviour()
+///     {
+///         MyEvent.AddListener(OnEventTriggered);
+///         MyEvent.AddOneTimeListener(OnEventTriggeredOneTime);
+///     }
+/// 
+///     public void Update()
+///     {
+///         MyEvent.Invoke(this);
+///     }
+/// 
+///     private void OnEventTriggered(MyBehaviour sender)
+///     {
+///         Console.WriteLine($"{sender.Id}'s event occurred!");
+///     }
+/// 
+///     private static void OnEventTriggeredOneTime(MyBehaviour sender)
+///     {
+///         Console.WriteLine($"{sender.Id}'s event called once!");
+///     }
+/// }
+/// </code>
+/// The output of the example code above would be: 
+/// <code>
+/// [Id]'s event occurred!
+/// [Id]'s event called once!
+/// [Id]'s event occurred!
+/// [Id]'s event occurred!
+/// [Id]'s event occurred!
+/// ...
+/// </code>
+/// 
+/// </summary>
+/// <typeparam name="TSender">Sender type</typeparam>
+public class Event<TSender> where TSender : class
+{
+    // We use Ascending order because draw calls are running from last to first
+    private static readonly Comparer<ListenerData> SortByAscendingPriority = Comparer<ListenerData>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private ILogger _logger = ILogger.Shared;
+    public ILogger Logger { get => _logger; set => _logger = value ?? ILogger.Shared; }
+
+    private readonly List<ListenerData> listeners = null!;
+    private readonly List<ListenerData> onceListeners = null!;
+
+    /// <summary>
+    /// Subscribes the callback to be invoked whenever the event is triggered.
+    /// </summary>
+    /// <param name="listener">The callback to be called when the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = listeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        listeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Subscribes the callback to be invoked the next time the event is triggered. The callback will be called only once.
+    /// </summary>
+    /// <param name="listener">The callback to be called the next time the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddOneTimeListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = onceListeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        onceListeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddListener(EventHandler)"/></param>
+    public void RemoveListener(EventHandler listener)
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            if (listeners[i].Callback == listener)
+            {
+                listeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/></param>
+    public void RemoveOneTimeListener(EventHandler listener)
+    {
+        for (int i = 0; i < onceListeners.Count; i++)
+            if (onceListeners[i].Callback == listener)
+            {
+                onceListeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes all listeners that was previously registered by either <see cref="AddListener(EventHandler)"/> or <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    public void Clear() { listeners.Clear(); onceListeners.Clear(); }
+
+    /// <summary>
+    /// Triggers the event.
+    /// </summary>
+    /// <param name="sender">The caller that's triggering this event.</param>
+    public void Invoke(TSender sender)
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            try { listeners[i].Callback.Invoke(sender); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{listeners[i].Callback.Method.DeclaringType?.FullName}.{listeners[i].Callback.Method.Name}({sender})";
+                EventHelpers.LogInvocationException(listeners[i].Callback.Target ?? sender, Logger, exception, methodCallRepresentation);
+            }
+
+        for (int i = onceListeners.Count - 1; i >= 0; i--)
+        {
+            try { onceListeners[i].Callback.Invoke(sender); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{onceListeners[i].Callback.Method.DeclaringType?.FullName}.{onceListeners[i].Callback.Method.Name}({sender})";
+                EventHelpers.LogInvocationException(onceListeners[i].Callback.Target ?? sender, Logger, exception, methodCallRepresentation);
+            }
+            onceListeners.RemoveAt(i);
+        }
+    }
+
+    public Event(int initialListenerCount = 4, int initialOnceListenerCount = 2)
+    {
+        listeners = new(initialListenerCount);
+        onceListeners = new(initialOnceListenerCount);
+    }
+
+    public Event()
+    {
+        listeners = new(4);
+        onceListeners = new(2);
+    }
+
+    public delegate void EventHandler(TSender sender);
+    private record struct ListenerData(EventHandler Callback, int Priority);
+}
+
+/// <summary>
+/// Represents an event with sender and argument parameters.
+/// <para>Example usage:</para> 
+/// <code>
+/// public class MyBehaviour : Behaviour, IUpdate
+/// {
+///     public readonly Event&lt;MyBehaviour, MyArguments&gt; MyEvent = new();
+/// 
+///     private int myInt = 0;
+///     private bool myBool = false;
+/// 
+///     public MyBehaviour()
+///     {
+///         MyEvent.AddOneTimeListener(OnEventTriggeredOneTime);
+///         MyEvent.AddListener(OnEventTriggered);
+///     }
+/// 
+///     public void Update()
+///     {
+///         MyEvent.Invoke(this, new MyArguments(myInt, myBool));
+///         myInt++;
+///         myBool = !myBool;
+///     }
+/// 
+///     private void OnEventTriggered(MyBehaviour sender, MyArguments args)
+///     {
+///         Console.WriteLine($"{sender.Id}'s event occurred with MyInt: {args.MyInt} and MyBool {args.MyBool}!");
+///     }
+/// 
+///     private static void OnEventTriggeredOneTime(MyBehaviour sender, MyArguments args)
+///     {
+///         Console.WriteLine($"{sender.Id}'s event called once with MyInt: {args.MyInt} and MyBool {args.MyBool}!");
+///     }
+/// 
+///     public readonly record struct MyArguments(int MyInt, bool MyBool);
+/// }
+/// </code>
+/// The output of the example code above would be: 
+/// <code>
+/// [Id]'s event occurred with MyInt: 0 and MyBool False!
+/// [Id]'s event called once with MyInt: 0 and MyBool False!
+/// [Id]'s event occurred with MyInt: 1 and MyBool True!
+/// [Id]'s event occurred with MyInt: 2 and MyBool False!
+/// [Id]'s event occurred with MyInt: 3 and MyBool True!
+/// ...
+/// </code>
+/// 
+/// </summary>
+/// <typeparam name="TSender">Sender type</typeparam>
+public class Event<TSender, TArguments> where TSender : class
+{
+    // We use Ascending order because draw calls are running from last to first
+    private static readonly Comparer<ListenerData> SortByAscendingPriority = Comparer<ListenerData>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private ILogger _logger = ILogger.Shared;
+    public ILogger Logger { get => _logger; set => _logger = value ?? ILogger.Shared; }
+
+    private readonly List<ListenerData> listeners = null!;
+    private readonly List<ListenerData> onceListeners = null!;
+
+    /// <summary>
+    /// Subscribes the callback to be invoked whenever the event is triggered.
+    /// </summary>
+    /// <param name="listener">The callback to be called when the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = listeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        listeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Subscribes the callback to be invoked the next time the event is triggered. The callback will be called only once.
+    /// </summary>
+    /// <param name="listener">The callback to be called the next time the event is triggered.</param>
+    /// <param name="priority">Priority of the callback.</param>
+    public void AddOneTimeListener(EventHandler listener, int priority = 0)
+    {
+        ListenerData listenerData = new(listener, priority);
+
+        int insertIndex = onceListeners.BinarySearch(listenerData, SortByAscendingPriority);
+        if (insertIndex < 0)
+            insertIndex = ~insertIndex;
+
+        onceListeners.Insert(insertIndex, listenerData);
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddListener(EventHandler)"/></param>
+    public void RemoveListener(EventHandler listener)
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            if (listeners[i].Callback == listener)
+            {
+                listeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes the callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    /// <param name="listener">The callback that was previously registered by <see cref="AddOneTimeListener(EventHandler)"/></param>
+    public void RemoveOneTimeListener(EventHandler listener)
+    {
+        for (int i = 0; i < onceListeners.Count; i++)
+            if (onceListeners[i].Callback == listener)
+            {
+                onceListeners.RemoveAt(i);
+                return;
+            }
+    }
+
+    /// <summary>
+    /// Unsubscribes all listeners that was previously registered by either <see cref="AddListener(EventHandler)"/> or <see cref="AddOneTimeListener(EventHandler)"/>.
+    /// </summary>
+    public void Clear() { listeners.Clear(); onceListeners.Clear(); }
+
+    /// <summary>
+    /// Triggers the event.
+    /// </summary>
+    /// <param name="sender">The caller that's triggering this event.</param>
+    /// <param name="args">The arguments provided for this event.</param>
+    public void Invoke(TSender sender, TArguments args)
+    {
+        for (int i = listeners.Count - 1; i >= 0; i--)
+            try { listeners[i].Callback.Invoke(sender, args); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{listeners[i].Callback.Method.DeclaringType?.FullName}.{listeners[i].Callback.Method.Name}({sender}, {args})";
+                EventHelpers.LogInvocationException(listeners[i].Callback.Target ?? sender, Logger, exception, methodCallRepresentation);
+            }
+
+        for (int i = onceListeners.Count - 1; i >= 0; i--)
+        {
+            try { onceListeners[i].Callback.Invoke(sender, args); }
+            catch (Exception exception)
+            {
+                string methodCallRepresentation = $"{onceListeners[i].Callback.Method.DeclaringType?.FullName}.{onceListeners[i].Callback.Method.Name}({sender}, {args})";
+                EventHelpers.LogInvocationException(onceListeners[i].Callback.Target ?? sender, Logger, exception, methodCallRepresentation);
+            }
+            onceListeners.RemoveAt(i);
+        }
+    }
+
+    public Event(int initialListenerCount = 4, int initialOnceListenerCount = 2)
+    {
+        listeners = new(initialListenerCount);
+        onceListeners = new(initialOnceListenerCount);
+    }
+
+    public Event()
+    {
+        listeners = new(4);
+        onceListeners = new(2);
+    }
+
+    public delegate void EventHandler(TSender sender, TArguments args);
+    private record struct ListenerData(EventHandler Callback, int Priority);
+}
+
+internal static class EventHelpers
+{
+    public static void LogInvocationException(object sender, ILogger logger, Exception exception, string methodCallRepresentation)
+    {
+        logger.LogException(sender, exception);
+        logger.LogError(sender, $"Unexpected exception on invocation of method {methodCallRepresentation}");
+    }
+}

Engine.Core/Helpers/IPool.cs

@@ -0,0 +1,10 @@
+namespace Syntriax.Engine.Core;
+
+public interface IPool<T>
+{
+    Event<IPool<T>, T> OnRemoved { get; }
+    Event<IPool<T>, T> OnReturned { get; }
+
+    T Get();
+    void Return(T item);
+}

Engine.Core/Helpers/ListPool.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+
+namespace Syntriax.Engine.Core;
+
+public class ListPool<T> : IPool<List<T>>
+{
+    public Event<IPool<List<T>>, List<T>> OnReturned { get; } = new();
+    public Event<IPool<List<T>>, List<T>> OnRemoved { get; } = new();
+
+    private readonly Func<List<T>> generator = null!;
+    private readonly Queue<List<T>> queue = new();
+
+    public List<T> Get()
+    {
+        if (!queue.TryDequeue(out List<T>? result))
+            result = generator();
+
+        result.Clear();
+        OnRemoved?.Invoke(this, result);
+        return result;
+    }
+
+    public void Return(List<T> list)
+    {
+        if (queue.Contains(list))
+            return;
+
+        list.Clear();
+        queue.Enqueue(list);
+        OnReturned?.Invoke(this, list);
+    }
+
+    public ListPool(int initialListCount = 1, int initialListCapacity = 32)
+    {
+        generator = () => new(initialListCapacity);
+        for (int i = 0; i < initialListCount; i++)
+            queue.Enqueue(generator());
+    }
+}

Engine.Core/Helpers/Pool.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+
+namespace Syntriax.Engine.Core;
+
+public class Pool<T> : IPool<T>
+{
+    public Event<IPool<T>, T> OnRemoved { get; } = new();
+    public Event<IPool<T>, T> OnReturned { get; } = new();
+
+    private readonly Func<T> generator = null!;
+    private readonly Queue<T> queue = new();
+
+    public T Get()
+    {
+        if (!queue.TryDequeue(out T? result))
+            result = generator();
+
+        OnRemoved?.Invoke(this, result);
+        return result;
+    }
+
+    public void Return(T item)
+    {
+        if (queue.Contains(item))
+            return;
+
+        queue.Enqueue(item);
+        OnReturned?.Invoke(this, item);
+    }
+
+    public Pool(Func<T> generator, int initialCapacity = 1)
+    {
+        this.generator = generator;
+        for (int i = 0; i < initialCapacity; i++)
+            queue.Enqueue(generator());
+    }
+}

Engine.Core/Helpers/Progression/IReadOnlyProgressionTracker.cs

@@ -2,12 +2,11 @@ namespace Syntriax.Engine.Core;
 
 public interface IReadOnlyProgressionTracker
 {
-    event ProgressionUpdatedEventHandler? OnUpdated;
-    event ProgressionEndedEventHandler? OnEnded;
+    Event<IReadOnlyProgressionTracker, ProgressionUpdatedArguments> OnUpdated { get; }
+    Event<IReadOnlyProgressionTracker> OnEnded { get; }
 
     float Progression { get; }
     string Status { get; }
 
-    delegate void ProgressionUpdatedEventHandler(IReadOnlyProgressionTracker sender, float previousProgression, string previousStatus);
-    delegate void ProgressionEndedEventHandler(IReadOnlyProgressionTracker sender);
+    readonly record struct ProgressionUpdatedArguments(float PreviousProgression, string PreviousStatus);
 }

Engine.Core/Helpers/Progression/ProgressionTracker.cs

@@ -2,8 +2,8 @@ namespace Syntriax.Engine.Core;
 
 public class ProgressionTracker : IProgressionTracker
 {
-    public event IReadOnlyProgressionTracker.ProgressionUpdatedEventHandler? OnUpdated = null;
-    public event IReadOnlyProgressionTracker.ProgressionEndedEventHandler? OnEnded = null;
+    public Event<IReadOnlyProgressionTracker, IReadOnlyProgressionTracker.ProgressionUpdatedArguments> OnUpdated { get; } = new();
+    public Event<IReadOnlyProgressionTracker> OnEnded { get; } = new();
 
     public float Progression { get; private set; } = 0f;
     public string Status { get; private set; } = "Default";
@@ -19,10 +19,10 @@ public class ProgressionTracker : IProgressionTracker
         Progression = progression.Clamp(Progression, 1f);
         Status = status;
 
-        OnUpdated?.InvokeSafe(this, previousProgression, previousStatus);
+        OnUpdated?.Invoke(this, new(previousProgression, previousStatus));
 
         if (progression >= 1f)
-            OnEnded?.InvokeSafe(this);
+            OnEnded?.Invoke(this);
     }
 
     void IProgressionTracker.Reset()
@@ -30,7 +30,7 @@ public class ProgressionTracker : IProgressionTracker
         Progression = 0f;
         Status = "Default";
 
-        OnUpdated = null;
-        OnEnded = null;
+        OnUpdated.Clear();
+        OnEnded.Clear();
     }
 }

Engine.Core/Math.cs

@@ -6,29 +6,29 @@ namespace Syntriax.Engine.Core;
 public static class Math
 {
     /// <summary>
-    /// The value of Pi (π), a mathematical constant approximately equal to 3.14159.
+    /// The value of Pi (π).
     /// </summary>
-    public const float PI = 3.1415926535897932f;
+    public const float Pi = 3.1415926535897932f;
 
     /// <summary>
-    /// The value of Tau (τ), a mathematical constant equal to 2π, approximately equal to 6.28319.
+    /// The value of Tau (τ), mathematical constant equal to 2π.
     /// </summary>
-    public const float Tau = 2f * PI;
+    public const float Tau = 2f * Pi;
 
     /// <summary>
-    /// The base of the natural logarithm, approximately equal to 2.71828.
+    /// The base of the natural logarithm.
     /// </summary>
     public const float E = 2.718281828459045f;
 
     /// <summary>
     /// The conversion factor from radians to degrees.
     /// </summary>
-    public const float RadianToDegree = 180f / PI;
+    public const float RadianToDegree = 180f / Pi;
 
     /// <summary>
     /// The conversion factor from degrees to radians.
     /// </summary>
-    public const float DegreeToRadian = PI / 180f;
+    public const float DegreeToRadian = Pi / 180f;
 
     /// <summary>
     /// Gets one minus of given <see cref="T"/>.

Engine.Core/Primitives/AABB.cs

@@ -38,6 +38,9 @@ public readonly struct AABB(Vector2D lowerBoundary, Vector2D upperBoundary)
     /// </summary>
     public readonly Vector2D SizeHalf => Size * .5f;
 
+    public static bool operator ==(AABB left, AABB right) => left.UpperBoundary == right.UpperBoundary && left.LowerBoundary == right.LowerBoundary;
+    public static bool operator !=(AABB left, AABB right) => left.UpperBoundary != right.UpperBoundary || left.LowerBoundary != right.LowerBoundary;
+
     /// <summary>
     /// Creates an <see cref="AABB"/> from a collection of <see cref="Vector2D"/>s.
     /// </summary>
@@ -63,12 +66,6 @@ public readonly struct AABB(Vector2D lowerBoundary, Vector2D upperBoundary)
         return new(lowerBoundary, upperBoundary);
     }
 
-    /// <summary>
-    /// Converts the <see cref="AABB"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="AABB"/>.</returns>
-    public override string ToString() => $"{nameof(AABB)}({LowerBoundary}, {UpperBoundary})";
-
     /// <summary>
     /// Checks if two <see cref="AABB"/>s are approximately equal.
     /// </summary>
@@ -78,6 +75,25 @@ public readonly struct AABB(Vector2D lowerBoundary, Vector2D upperBoundary)
     /// <returns><see cref="true"/> if the <see cref="AABB"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
     public static bool ApproximatelyEquals(AABB left, AABB right, float epsilon = float.Epsilon)
         => left.LowerBoundary.ApproximatelyEquals(right.LowerBoundary, epsilon) && left.UpperBoundary.ApproximatelyEquals(right.UpperBoundary, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="AABB"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="AABB"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="AABB"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is AABB aabb && this == aabb;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="AABB"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="AABB"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(LowerBoundary, UpperBoundary);
+
+    /// <summary>
+    /// Converts the <see cref="AABB"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="AABB"/>.</returns>
+    public override string ToString() => $"{nameof(AABB)}({LowerBoundary}, {UpperBoundary})";
 }
 
 /// <summary>

Engine.Core/Primitives/Circle.cs

@@ -38,6 +38,9 @@ public readonly struct Circle(Vector2D center, float radius)
     /// </summary>
     public static readonly Circle UnitCircle = new(Vector2D.Zero, 1f);
 
+    public static bool operator ==(Circle left, Circle right) => left.Center == right.Center && left.Radius == right.Radius;
+    public static bool operator !=(Circle left, Circle right) => left.Center != right.Center || left.Radius != right.Radius;
+
     /// <summary>
     /// Sets the center of the <see cref="Circle"/>.
     /// </summary>
@@ -77,6 +80,25 @@ public readonly struct Circle(Vector2D center, float radius)
     /// <returns><see cref="true"/> if the <see cref="Circle"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
     public static bool ApproximatelyEquals(Circle left, Circle right, float epsilon = float.Epsilon)
         => left.Center.ApproximatelyEquals(right.Center, epsilon) && left.Radius.ApproximatelyEquals(right.Radius, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Circle"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Circle"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Circle"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Circle circle && this == circle;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Circle"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Circle"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Center, Radius);
+
+    /// <summary>
+    /// Converts the <see cref="Circle"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Circle"/>.</returns>
+    public override string ToString() => $"{nameof(Circle)}({Center}, {Radius})";
 }
 
 /// <summary>

Engine.Core/Primitives/ColorHSV.cs

@@ -27,49 +27,19 @@ public readonly struct ColorHSV(float hue, float saturation, float value)
     /// </summary>
     public readonly float Value = value.Clamp(0f, 1f);
 
-    public static ColorHSV operator -(ColorHSV color) => new(color.Hue.OneMinus().Clamp(0f, 1f), color.Saturation.OneMinus().Clamp(0f, 1f), color.Value.OneMinus().Clamp(0f, 1f));
-    public static ColorHSV operator +(ColorHSV left, ColorHSV right) => new((left.Hue + right.Hue).Clamp(0f, 1f), (left.Saturation + right.Saturation).Clamp(0f, 1f), (left.Value + right.Value).Clamp(0f, 1f));
-    public static ColorHSV operator -(ColorHSV left, ColorHSV right) => new((left.Hue - right.Hue).Clamp(0f, 1f), (left.Saturation - right.Saturation).Clamp(0f, 1f), (left.Value - right.Value).Clamp(0f, 1f));
-    public static ColorHSV operator *(ColorHSV left, ColorHSV right) => new((left.Hue * right.Hue).Clamp(0f, 1f), (left.Saturation * right.Saturation).Clamp(0f, 1f), (left.Value * right.Value).Clamp(0f, 1f));
-    public static ColorHSV operator *(ColorHSV color, float value) => new((color.Hue * value).Clamp(0f, 1f), (color.Saturation * value).Clamp(0f, 1f), (color.Value * value).Clamp(0f, 1f));
-    public static ColorHSV operator *(float value, ColorHSV color) => new((color.Hue * value).Clamp(0f, 1f), (color.Saturation * value).Clamp(0f, 1f), (color.Value * value).Clamp(0f, 1f));
-    public static ColorHSV operator /(ColorHSV color, float value) => new((color.Hue / value).Clamp(0f, 1f), (color.Saturation / value).Clamp(0f, 1f), (color.Value / value).Clamp(0f, 1f));
-    public static bool operator ==(ColorHSV left, ColorHSV right) => left.Hue.ApproximatelyEquals(right.Hue) && left.Saturation.ApproximatelyEquals(right.Saturation) && left.Value.ApproximatelyEquals(right.Value);
-    public static bool operator !=(ColorHSV left, ColorHSV right) => !left.Hue.ApproximatelyEquals(right.Hue) || !left.Saturation.ApproximatelyEquals(right.Saturation) || !left.Value.ApproximatelyEquals(right.Value);
+    public static ColorHSV operator -(ColorHSV color) => new(color.Hue.OneMinus(), color.Saturation.OneMinus(), color.Value.OneMinus());
+    public static ColorHSV operator +(ColorHSV left, ColorHSV right) => new(left.Hue + right.Hue, left.Saturation + right.Saturation, left.Value + right.Value);
+    public static ColorHSV operator -(ColorHSV left, ColorHSV right) => new(left.Hue - right.Hue, left.Saturation - right.Saturation, left.Value - right.Value);
+    public static ColorHSV operator *(ColorHSV left, ColorHSV right) => new(left.Hue * right.Hue, left.Saturation * right.Saturation, left.Value * right.Value);
+    public static ColorHSV operator *(ColorHSV color, float value) => new(color.Hue * value, color.Saturation * value, color.Value * value);
+    public static ColorHSV operator *(float value, ColorHSV color) => new(color.Hue * value, color.Saturation * value, color.Value * value);
+    public static ColorHSV operator /(ColorHSV color, float value) => new(color.Hue / value, color.Saturation / value, color.Value / value);
+    public static bool operator ==(ColorHSV left, ColorHSV right) => left.Hue == right.Hue && left.Saturation == right.Saturation && left.Value == right.Value;
+    public static bool operator !=(ColorHSV left, ColorHSV right) => left.Hue != right.Hue || left.Saturation != right.Saturation || left.Value != right.Value;
 
-    public static implicit operator ColorHSV(ColorRGBA rgba) => (ColorRGB)rgba;
-    public static implicit operator ColorHSV(ColorRGB rgb)
-    {
-        float hue;
-        float saturation;
-        float value;
-
-        float rd = rgb.R / 255f;
-        float gd = rgb.G / 255f;
-        float bd = rgb.B / 255f;
-
-        float max = Math.Max(rd, Math.Max(gd, bd));
-        float min = Math.Min(rd, Math.Min(gd, bd));
-        float delta = max - min;
-
-        if (delta.ApproximatelyEquals(0))
-            hue = 0f;
-        else if (max.ApproximatelyEquals(rd))
-            hue = 60f * ((gd - bd) / delta % 6f);
-        else if (max.ApproximatelyEquals(gd))
-            hue = 60f * (((bd - rd) / delta) + 2f);
-        else
-            hue = 60f * (((rd - gd) / delta) + 4f);
-
-        if (hue < 0f)
-            hue += 360f;
-
-        hue /= 360f;
-        saturation = max.ApproximatelyEquals(0f) ? 0f : delta / max;
-        value = max;
-
-        return new(hue, saturation, value);
-    }
+    public static implicit operator ColorHSV(ColorHSVA hsva) => new(hsva.Hue, hsva.Saturation, hsva.Value);
+    public static implicit operator ColorHSV(ColorRGBA rgba) => (ColorHSVA)rgba;
+    public static implicit operator ColorHSV(ColorRGB rgb) => (ColorHSVA)rgb;
 
     /// <summary>
     /// Inverts the given <see cref="ColorHSV"/>.
@@ -110,14 +80,6 @@ public readonly struct ColorHSV(float hue, float saturation, float value)
     /// <returns>The result of dividing the <see cref="ColorHSV"/> by the scalar value.</returns>
     public static ColorHSV Divide(ColorHSV color, float value) => color / value;
 
-    /// <summary>
-    /// Calculates the <see cref="ColorHSV"/> from one point to another.
-    /// </summary>
-    /// <param name="from">The starting point.</param>
-    /// <param name="to">The ending point.</param>
-    /// <returns>The <see cref="ColorHSV"/> from the starting point to the ending point.</returns>
-    public static ColorHSV FromTo(ColorHSV from, ColorHSV to) => to - from;
-
     /// <summary>
     /// Performs linear interpolation between two <see cref="ColorHSV"/>s.
     /// </summary>
@@ -125,13 +87,14 @@ public readonly struct ColorHSV(float hue, float saturation, float value)
     /// <param name="to">The ending <see cref="ColorHSV"/> (t = 1).</param>
     /// <param name="t">The interpolation parameter.</param>
     /// <returns>The interpolated <see cref="ColorHSV"/>.</returns>
-    public static ColorHSV Lerp(ColorHSV from, ColorHSV to, float t) => from + FromTo(from, to) * t;
+    public static ColorHSV Lerp(ColorHSV from, ColorHSV to, float t)
+    {
+        float hueDiff = to.Hue - from.Hue;
+        float saturationDiff = to.Saturation - from.Saturation;
+        float valueDiff = to.Value - from.Value;
 
-    /// <summary>
-    /// Converts the <see cref="ColorHSV"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="ColorHSV"/>.</returns>
-    public override string ToString() => $"{nameof(ColorHSV)}({Hue}, {Saturation}, {Value})";
+        return from + new ColorHSV(hueDiff * t, saturationDiff * t, valueDiff * t);
+    }
 
     /// <summary>
     /// Checks if two <see cref="ColorHSV"/>s are approximately equal within a specified epsilon range.
@@ -148,13 +111,19 @@ public readonly struct ColorHSV(float hue, float saturation, float value)
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="ColorHSV"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="ColorHSV"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is ColorHSV objVec && Hue.Equals(objVec.Hue) && Saturation.Equals(objVec.Saturation) && Value.Equals(objVec.Value);
+    public override bool Equals(object? obj) => obj is ColorHSV colorHSV && this == colorHSV;
 
     /// <summary>
     /// Generates a hash code for the <see cref="ColorHSV"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="ColorHSV"/>.</returns>
     public override int GetHashCode() => System.HashCode.Combine(Hue, Saturation, Value);
+
+    /// <summary>
+    /// Converts the <see cref="ColorHSV"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="ColorHSV"/>.</returns>
+    public override string ToString() => $"{nameof(ColorHSV)}({Hue}, {Saturation}, {Value})";
 }
 
 /// <summary>
@@ -174,9 +143,6 @@ public static class ColorHSVExtensions
     /// <inheritdoc cref="ColorHSV.Divide(ColorHSV, ColorHSV)" />
     public static ColorHSV Divide(this ColorHSV color, float value) => ColorHSV.Divide(color, value);
 
-    /// <inheritdoc cref="ColorHSV.FromTo(ColorHSV, ColorHSV)" />
-    public static ColorHSV FromTo(this ColorHSV from, ColorHSV to) => ColorHSV.FromTo(from, to);
-
     /// <inheritdoc cref="ColorHSV.Lerp(ColorHSV, ColorHSV, float)" />
     public static ColorHSV Lerp(this ColorHSV from, ColorHSV to, float t) => ColorHSV.Lerp(from, to, t);
 

Engine.Core/Primitives/ColorHSVA.cs

@@ -0,0 +1,189 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents an HSV color.
+/// </summary>
+/// <param name="hue">Hue of the <see cref="ColorHSVA"/>.</param>
+/// <param name="saturation">Saturation of the <see cref="ColorHSVA"/>.</param>
+/// <param name="value">Value of the <see cref="ColorHSVA"/>.</param>
+/// <param name="alpha">Alpha of the <see cref="ColorHSVA"/>.</param>
+/// <remarks>
+/// Initializes a new instance of the <see cref="ColorHSVA"/> struct with the specified values.
+/// </remarks>
+[System.Diagnostics.DebuggerDisplay("{ToString(),nq}")]
+public readonly struct ColorHSVA(float hue, float saturation, float value, float alpha = 1)
+{
+    /// <summary>
+    /// The Hue value of the <see cref="ColorHSVA"/>.
+    /// </summary>
+    public readonly float Hue = hue.Clamp(0f, 1f);
+
+    /// <summary>
+    /// The Saturation value of the <see cref="ColorHSVA"/>.
+    /// </summary>
+    public readonly float Saturation = saturation.Clamp(0f, 1f);
+
+    /// <summary>
+    /// The Value value of the <see cref="ColorHSVA"/>.
+    /// </summary>
+    public readonly float Value = value.Clamp(0f, 1f);
+
+    /// <summary>
+    /// The Alpha value of the <see cref="ColorHSVA"/>.
+    /// </summary>
+    public readonly float Alpha = alpha;
+
+    public static ColorHSVA operator -(ColorHSVA color) => new(color.Hue.OneMinus(), color.Saturation.OneMinus(), color.Value.OneMinus(), color.Alpha);
+    public static ColorHSVA operator +(ColorHSVA left, ColorHSVA right) => new(left.Hue + right.Hue, left.Saturation + right.Saturation, left.Value + right.Value, left.Alpha + right.Alpha);
+    public static ColorHSVA operator -(ColorHSVA left, ColorHSVA right) => new(left.Hue - right.Hue, left.Saturation - right.Saturation, left.Value - right.Value, left.Alpha - right.Alpha);
+    public static ColorHSVA operator *(ColorHSVA left, ColorHSVA right) => new(left.Hue * right.Hue, left.Saturation * right.Saturation, left.Value * right.Value, left.Alpha * right.Alpha);
+    public static ColorHSVA operator *(ColorHSVA color, float value) => new(color.Hue * value, color.Saturation * value, color.Value * value, color.Alpha * value);
+    public static ColorHSVA operator *(float value, ColorHSVA color) => new(color.Hue * value, color.Saturation * value, color.Value * value, color.Alpha * value);
+    public static ColorHSVA operator /(ColorHSVA color, float value) => new(color.Hue / value, color.Saturation / value, color.Value / value, color.Alpha / value);
+    public static bool operator ==(ColorHSVA left, ColorHSVA right) => left.Hue == right.Hue && left.Saturation == right.Saturation && left.Value == right.Value;
+    public static bool operator !=(ColorHSVA left, ColorHSVA right) => left.Hue != right.Hue || left.Saturation != right.Saturation || left.Value != right.Value;
+
+    public static implicit operator ColorHSVA(ColorHSV hsv) => new(hsv.Hue, hsv.Saturation, hsv.Value, 1f);
+    public static implicit operator ColorHSVA(ColorRGB rgb) => (ColorRGBA)rgb;
+    public static implicit operator ColorHSVA(ColorRGBA rgba)
+    {
+        float hue;
+        float saturation;
+        float value;
+
+        float rd = rgba.R / 255f;
+        float gd = rgba.G / 255f;
+        float bd = rgba.B / 255f;
+
+        float max = Math.Max(rd, Math.Max(gd, bd));
+        float min = Math.Min(rd, Math.Min(gd, bd));
+        float delta = max - min;
+
+        if (delta.ApproximatelyEquals(0))
+            hue = 0f;
+        else if (max.ApproximatelyEquals(rd))
+            hue = 60f * ((gd - bd) / delta % 6f);
+        else if (max.ApproximatelyEquals(gd))
+            hue = 60f * (((bd - rd) / delta) + 2f);
+        else
+            hue = 60f * (((rd - gd) / delta) + 4f);
+
+        if (hue < 0f)
+            hue += 360f;
+
+        hue /= 360f;
+        saturation = max.ApproximatelyEquals(0f) ? 0f : delta / max;
+        value = max;
+
+        return new(hue, saturation, value, rgba.A / 255f);
+    }
+
+    /// <summary>
+    /// Inverts the given <see cref="ColorHSVA"/>.
+    /// </summary>
+    /// <param name="color">The <see cref="ColorHSVA"/>.</param>
+    /// <returns>The inverted <see cref="ColorHSVA"/>.</returns>
+    public static ColorHSVA Invert(ColorHSVA color) => -color;
+
+    /// <summary>
+    /// Adds two <see cref="ColorHSVA"/>s.
+    /// </summary>
+    /// <param name="left">The first <see cref="ColorHSVA"/>.</param>
+    /// <param name="right">The second <see cref="ColorHSVA"/>.</param>
+    /// <returns>The sum of the two <see cref="ColorHSVA"/>s.</returns>
+    public static ColorHSVA Add(ColorHSVA left, ColorHSVA right) => left + right;
+
+    /// <summary>
+    /// Subtracts one <see cref="ColorHSVA"/> from another.
+    /// </summary>
+    /// <param name="left">The <see cref="ColorHSVA"/> to subtract from.</param>
+    /// <param name="right">The <see cref="ColorHSVA"/> to subtract.</param>
+    /// <returns>The result of subtracting the second <see cref="ColorHSVA"/> from the first.</returns>
+    public static ColorHSVA Subtract(ColorHSVA left, ColorHSVA right) => left - right;
+
+    /// <summary>
+    /// Multiplies a <see cref="ColorHSVA"/> by a scalar value.
+    /// </summary>
+    /// <param name="color">The <see cref="ColorHSVA"/>.</param>
+    /// <param name="value">The scalar value.</param>
+    /// <returns>The result of multiplying the <see cref="ColorHSVA"/> by the scalar value.</returns>
+    public static ColorHSVA Multiply(ColorHSVA color, float value) => color * value;
+
+    /// <summary>
+    /// Divides a <see cref="ColorHSVA"/> by a scalar value.
+    /// </summary>
+    /// <param name="color">The <see cref="ColorHSVA"/>.</param>
+    /// <param name="value">The scalar value.</param>
+    /// <returns>The result of dividing the <see cref="ColorHSVA"/> by the scalar value.</returns>
+    public static ColorHSVA Divide(ColorHSVA color, float value) => color / value;
+
+    /// <summary>
+    /// Performs linear interpolation between two <see cref="ColorHSVA"/>s.
+    /// </summary>
+    /// <param name="from">The starting <see cref="ColorHSVA"/> (t = 0).</param>
+    /// <param name="to">The ending <see cref="ColorHSVA"/> (t = 1).</param>
+    /// <param name="t">The interpolation parameter.</param>
+    /// <returns>The interpolated <see cref="ColorHSVA"/>.</returns>
+    public static ColorHSVA Lerp(ColorHSVA from, ColorHSVA to, float t)
+    {
+        float hueDiff = to.Hue - from.Hue;
+        float saturationDiff = to.Saturation - from.Saturation;
+        float valueDiff = to.Value - from.Value;
+        float alphaDiff = to.Alpha - from.Alpha;
+
+        return from + new ColorHSVA(hueDiff * t, saturationDiff * t, valueDiff * t, alphaDiff * t);
+    }
+
+    /// <summary>
+    /// Checks if two <see cref="ColorHSVA"/>s are approximately equal within a specified epsilon range.
+    /// </summary>
+    /// <param name="left">The first <see cref="ColorHSVA"/>.</param>
+    /// <param name="right">The second <see cref="ColorHSVA"/>.</param>
+    /// <param name="epsilon">The epsilon range.</param>
+    /// <returns><see cref="true"/> if the <see cref="ColorHSVA"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
+    public static bool ApproximatelyEquals(ColorHSVA left, ColorHSVA right, float epsilon = float.Epsilon)
+        => left.Hue.ApproximatelyEquals(right.Hue, epsilon) && left.Saturation.ApproximatelyEquals(right.Saturation, epsilon) && left.Value.ApproximatelyEquals(right.Value, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="ColorHSVA"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="ColorHSVA"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="ColorHSVA"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is ColorHSVA colorHSVA && this == colorHSVA;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="ColorHSVA"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="ColorHSVA"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Hue, Saturation, Value);
+
+    /// <summary>
+    /// Converts the <see cref="ColorHSVA"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="ColorHSVA"/>.</returns>
+    public override string ToString() => $"{nameof(ColorHSVA)}({Hue}, {Saturation}, {Value})";
+}
+
+/// <summary>
+/// Provides extension methods for <see cref="ColorHSVA"/> type.
+/// </summary>
+public static class ColorHSVAExtensions
+{
+    /// <inheritdoc cref="ColorHSVA.Add(ColorHSVA, ColorHSVA)" />
+    public static ColorHSVA Add(this ColorHSVA color, ColorHSVA value) => ColorHSVA.Add(color, value);
+
+    /// <inheritdoc cref="ColorHSVA.Subtract(ColorHSVA, ColorHSVA)" />
+    public static ColorHSVA Subtract(this ColorHSVA color, ColorHSVA value) => ColorHSVA.Subtract(color, value);
+
+    /// <inheritdoc cref="ColorHSVA.Multiply(ColorHSVA, ColorHSVA)" />
+    public static ColorHSVA Multiply(this ColorHSVA color, float value) => ColorHSVA.Multiply(color, value);
+
+    /// <inheritdoc cref="ColorHSVA.Divide(ColorHSVA, ColorHSVA)" />
+    public static ColorHSVA Divide(this ColorHSVA color, float value) => ColorHSVA.Divide(color, value);
+
+    /// <inheritdoc cref="ColorHSVA.Lerp(ColorHSVA, ColorHSVA, float)" />
+    public static ColorHSVA Lerp(this ColorHSVA from, ColorHSVA to, float t) => ColorHSVA.Lerp(from, to, t);
+
+    /// <inheritdoc cref="ColorHSVA.ApproximatelyEquals(ColorHSVA, ColorHSVA, float) " />
+    public static bool ApproximatelyEquals(this ColorHSVA left, ColorHSVA right, float epsilon = float.Epsilon) => ColorHSVA.ApproximatelyEquals(left, right, epsilon);
+}

Engine.Core/Primitives/ColorRGB.cs

@@ -38,30 +38,8 @@ public readonly struct ColorRGB(byte r, byte g, byte b)
     public static bool operator !=(ColorRGB left, ColorRGB right) => left.R != right.R || left.G != right.G || left.B != right.B;
 
     public static implicit operator ColorRGB(ColorRGBA rgba) => new(rgba.R, rgba.G, rgba.B);
-    public static implicit operator ColorRGB(ColorHSV hsv)
-    {
-        float hue = hsv.Hue * 360f;
-        float chroma = hsv.Value * hsv.Saturation;
-        float x = chroma * (1f - Math.Abs(hue / 60f % 2f - 1f));
-        float m = hsv.Value - chroma;
-
-        float r1 = 0f;
-        float g1 = 0f;
-        float b1 = 0f;
-
-        if (hue < 60) { r1 = chroma; g1 = x; b1 = 0; }
-        else if (hue < 120) { r1 = x; g1 = chroma; b1 = 0; }
-        else if (hue < 180) { r1 = 0; g1 = chroma; b1 = x; }
-        else if (hue < 240) { r1 = 0; g1 = x; b1 = chroma; }
-        else if (hue < 300) { r1 = x; g1 = 0; b1 = chroma; }
-        else if (hue <= 360) { r1 = chroma; g1 = 0; b1 = x; }
-
-        byte r = (byte)Math.RoundToInt((r1 + m) * 255);
-        byte g = (byte)Math.RoundToInt((g1 + m) * 255);
-        byte b = (byte)Math.RoundToInt((b1 + m) * 255);
-
-        return new(r, g, b);
-    }
+    public static implicit operator ColorRGB(ColorHSVA hsva) => (ColorRGBA)hsva;
+    public static implicit operator ColorRGB(ColorHSV hsv) => (ColorRGBA)hsv;
 
     /// <summary>
     /// Inverts the given <see cref="ColorRGB"/>.
@@ -102,14 +80,6 @@ public readonly struct ColorRGB(byte r, byte g, byte b)
     /// <returns>The result of dividing the <see cref="ColorRGB"/> by the scalar value.</returns>
     public static ColorRGB Divide(ColorRGB color, float value) => color / value;
 
-    /// <summary>
-    /// Calculates the <see cref="ColorRGB"/> from one point to another.
-    /// </summary>
-    /// <param name="from">The starting point.</param>
-    /// <param name="to">The ending point.</param>
-    /// <returns>The <see cref="ColorRGB"/> from the starting point to the ending point.</returns>
-    public static ColorRGB FromTo(ColorRGB from, ColorRGB to) => to - from;
-
     /// <summary>
     /// Performs linear interpolation between two <see cref="ColorRGB"/>s.
     /// </summary>
@@ -117,26 +87,33 @@ public readonly struct ColorRGB(byte r, byte g, byte b)
     /// <param name="to">The ending <see cref="ColorRGB"/> (t = 1).</param>
     /// <param name="t">The interpolation parameter.</param>
     /// <returns>The interpolated <see cref="ColorRGB"/>.</returns>
-    public static ColorRGB Lerp(ColorRGB from, ColorRGB to, float t) => from + FromTo(from, to) * t;
+    public static ColorRGB Lerp(ColorRGB from, ColorRGB to, float t)
+    {
+        int redDiff = to.R - from.R;
+        int greenDiff = to.G - from.G;
+        int blueDiff = to.B - from.B;
 
-    /// <summary>
-    /// Converts the <see cref="ColorRGB"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="ColorRGB"/>.</returns>
-    public override string ToString() => $"{nameof(ColorRGB)}({R}, {G}, {B})";
+        return from + new ColorRGB((byte)(redDiff * t), (byte)(greenDiff * t), (byte)(blueDiff * t));
+    }
 
     /// <summary>
     /// Determines whether the specified object is equal to the current <see cref="ColorRGB"/>.
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="ColorRGB"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="ColorRGB"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is ColorRGB objVec && R.Equals(objVec.R) && G.Equals(objVec.G) && B.Equals(objVec.B);
+    public override bool Equals(object? obj) => obj is ColorRGB colorRGB && this == colorRGB;
 
     /// <summary>
     /// Generates a hash code for the <see cref="ColorRGB"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="ColorRGB"/>.</returns>
     public override int GetHashCode() => System.HashCode.Combine(R, G, B);
+
+    /// <summary>
+    /// Converts the <see cref="ColorRGB"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="ColorRGB"/>.</returns>
+    public override string ToString() => $"{nameof(ColorRGB)}({R}, {G}, {B})";
 }
 
 /// <summary>
@@ -156,9 +133,6 @@ public static class ColorRGBExtensions
     /// <inheritdoc cref="ColorRGB.Divide(ColorRGB, ColorRGB)" />
     public static ColorRGB Divide(this ColorRGB color, float value) => ColorRGB.Divide(color, value);
 
-    /// <inheritdoc cref="ColorRGB.FromTo(ColorRGB, ColorRGB)" />
-    public static ColorRGB FromTo(this ColorRGB from, ColorRGB to) => ColorRGB.FromTo(from, to);
-
     /// <inheritdoc cref="ColorRGB.Lerp(ColorRGB, ColorRGB, float)" />
     public static ColorRGB Lerp(this ColorRGB from, ColorRGB to, float t) => ColorRGB.Lerp(from, to, t);
 }

Engine.Core/Primitives/ColorRGBA.cs

@@ -44,7 +44,31 @@ public readonly struct ColorRGBA(byte r, byte g, byte b, byte a = 255)
     public static bool operator !=(ColorRGBA left, ColorRGBA right) => left.R != right.R || left.G != right.G || left.B != right.B || left.A != right.A;
 
     public static implicit operator ColorRGBA(ColorRGB rgb) => new(rgb.R, rgb.G, rgb.B, 255);
-    public static implicit operator ColorRGBA(ColorHSV hsv) => (ColorRGB)hsv;
+    public static implicit operator ColorRGBA(ColorHSV hsv) => (ColorHSVA)hsv;
+    public static implicit operator ColorRGBA(ColorHSVA hsva)
+    {
+        float hue = hsva.Hue * 360f;
+        float chroma = hsva.Value * hsva.Saturation;
+        float x = chroma * (1f - Math.Abs(hue / 60f % 2f - 1f));
+        float m = hsva.Value - chroma;
+
+        float r1 = 0f;
+        float g1 = 0f;
+        float b1 = 0f;
+
+        if (hue < 60) { r1 = chroma; g1 = x; b1 = 0; }
+        else if (hue < 120) { r1 = x; g1 = chroma; b1 = 0; }
+        else if (hue < 180) { r1 = 0; g1 = chroma; b1 = x; }
+        else if (hue < 240) { r1 = 0; g1 = x; b1 = chroma; }
+        else if (hue < 300) { r1 = x; g1 = 0; b1 = chroma; }
+        else if (hue <= 360) { r1 = chroma; g1 = 0; b1 = x; }
+
+        byte r = (byte)Math.RoundToInt((r1 + m) * 255);
+        byte g = (byte)Math.RoundToInt((g1 + m) * 255);
+        byte b = (byte)Math.RoundToInt((b1 + m) * 255);
+
+        return new(r, g, b, (byte)(hsva.Alpha * 255));
+    }
 
     /// <summary>
     /// Inverts the given <see cref="ColorRGBA"/>.
@@ -85,14 +109,6 @@ public readonly struct ColorRGBA(byte r, byte g, byte b, byte a = 255)
     /// <returns>The result of dividing the <see cref="ColorRGBA"/> by the scalar value.</returns>
     public static ColorRGBA Divide(ColorRGBA color, float value) => color / value;
 
-    /// <summary>
-    /// Calculates the <see cref="ColorRGBA"/> from one point to another.
-    /// </summary>
-    /// <param name="from">The starting point.</param>
-    /// <param name="to">The ending point.</param>
-    /// <returns>The <see cref="ColorRGBA"/> from the starting point to the ending point.</returns>
-    public static ColorRGBA FromTo(ColorRGBA from, ColorRGBA to) => to - from;
-
     /// <summary>
     /// Performs linear interpolation between two <see cref="ColorRGBA"/>s.
     /// </summary>
@@ -100,26 +116,34 @@ public readonly struct ColorRGBA(byte r, byte g, byte b, byte a = 255)
     /// <param name="to">The ending <see cref="ColorRGBA"/> (t = 1).</param>
     /// <param name="t">The interpolation parameter.</param>
     /// <returns>The interpolated <see cref="ColorRGBA"/>.</returns>
-    public static ColorRGBA Lerp(ColorRGBA from, ColorRGBA to, float t) => from + FromTo(from, to) * t;
+    public static ColorRGBA Lerp(ColorRGBA from, ColorRGBA to, float t)
+    {
+        int redDiff = to.R - from.R;
+        int greenDiff = to.G - from.G;
+        int blueDiff = to.B - from.B;
+        int alphaDiff = to.A - from.A;
 
-    /// <summary>
-    /// Converts the <see cref="ColorRGBA"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="ColorRGBA"/>.</returns>
-    public override string ToString() => $"{nameof(ColorRGBA)}({R}, {G}, {B}, {A})";
+        return from + new ColorRGBA((byte)(redDiff * t), (byte)(greenDiff * t), (byte)(blueDiff * t), (byte)(alphaDiff * t));
+    }
 
     /// <summary>
     /// Determines whether the specified object is equal to the current <see cref="ColorRGBA"/>.
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="ColorRGBA"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="ColorRGBA"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is ColorRGBA objVec && R.Equals(objVec.R) && G.Equals(objVec.G) && B.Equals(objVec.B) && A.Equals(objVec.A);
+    public override bool Equals(object? obj) => obj is ColorRGBA colorRGBA && this == colorRGBA;
 
     /// <summary>
     /// Generates a hash code for the <see cref="ColorRGBA"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="ColorRGBA"/>.</returns>
     public override int GetHashCode() => System.HashCode.Combine(R, G, B, A);
+
+    /// <summary>
+    /// Converts the <see cref="ColorRGBA"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="ColorRGBA"/>.</returns>
+    public override string ToString() => $"{nameof(ColorRGBA)}({R}, {G}, {B}, {A})";
 }
 
 /// <summary>
@@ -139,9 +163,6 @@ public static class ColorRGBAExtensions
     /// <inheritdoc cref="ColorRGBA.Divide(ColorRGBA, ColorRGBA)" />
     public static ColorRGBA Divide(this ColorRGBA color, float value) => ColorRGBA.Divide(color, value);
 
-    /// <inheritdoc cref="ColorRGBA.FromTo(ColorRGBA, ColorRGBA)" />
-    public static ColorRGBA FromTo(this ColorRGBA from, ColorRGBA to) => ColorRGBA.FromTo(from, to);
-
     /// <inheritdoc cref="ColorRGBA.Lerp(ColorRGBA, ColorRGBA, float)" />
     public static ColorRGBA Lerp(this ColorRGBA from, ColorRGBA to, float t) => ColorRGBA.Lerp(from, to, t);
 }

Engine.Core/Primitives/Line2D.cs

@@ -43,6 +43,9 @@ public readonly struct Line2D(Vector2D from, Vector2D to)
     /// </summary>
     public readonly float LengthSquared => From.FromTo(To).LengthSquared();
 
+    public static bool operator ==(Line2D left, Line2D right) => left.From == right.From && left.To == right.To;
+    public static bool operator !=(Line2D left, Line2D right) => left.From != right.From || left.To != right.To;
+
     /// <summary>
     /// The equation of the <see cref="Line2D"/> defined by this <see cref="Line2D"/> segment.
     /// </summary>
@@ -167,17 +170,14 @@ public readonly struct Line2D(Vector2D from, Vector2D to)
     /// </summary>
     public static Vector2D ClosestPointTo(Line2D line, Vector2D point)
     {
-        Vector2D edgeVector = line.From.FromTo(line.To);
-        Vector2D pointVector = point - line.From;
+        Vector2D lineRelativeVector = line.From.FromTo(line.To);
 
-        float t = (pointVector.X * edgeVector.X + pointVector.Y * edgeVector.Y) / (edgeVector.X * edgeVector.X + edgeVector.Y * edgeVector.Y);
+        Vector2D lineDirection = lineRelativeVector.Normalized;
+        Vector2D pointVector = line.From.FromTo(point);
 
-        t = Math.Max(0, Math.Min(1, t));
+        float dot = lineDirection.Dot(pointVector).Clamp(0f, lineRelativeVector.Magnitude);
 
-        float closestX = line.From.X + t * edgeVector.X;
-        float closestY = line.From.Y + t * edgeVector.Y;
-
-        return new Vector2D((float)closestX, (float)closestY);
+        return lineDirection * dot;
     }
 
     /// <summary>
@@ -189,6 +189,25 @@ public readonly struct Line2D(Vector2D from, Vector2D to)
     /// <returns><see cref="true"/> if the <see cref="Line2D"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
     public static bool ApproximatelyEquals(Line2D left, Line2D right, float epsilon = float.Epsilon)
         => left.From.ApproximatelyEquals(right.From, epsilon) && left.To.ApproximatelyEquals(right.To, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Line2D"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Line2D"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Line2D"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Line2D line2D && this == line2D;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Line2D"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Line2D"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(From, To);
+
+    /// <summary>
+    /// Converts the <see cref="Line2D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Line2D"/>.</returns>
+    public override string ToString() => $"{nameof(Line2D)}({From}, {To})";
 }
 
 /// <summary>
@@ -205,6 +224,9 @@ public static class Line2DExtensions
     /// <inheritdoc cref="Line2D.Intersects(Line2D, Vector2D)" />
     public static bool Intersects(this Line2D line, Vector2D point) => Line2D.Intersects(line, point);
 
+    /// <inheritdoc cref="Line2D.IntersectionPoint(Line2D, Line2D)" />
+    public static Vector2D IntersectionPoint(this Line2D left, Line2D right) => Line2D.IntersectionPoint(left, right);
+
     /// <inheritdoc cref="Line2D.GetT(Line2D, Vector2D)" />
     public static float GetT(this Line2D line, Vector2D point) => Line2D.GetT(line, point);
 
@@ -214,6 +236,9 @@ public static class Line2DExtensions
     /// <inheritdoc cref="Line2D.Intersects(Line2D, Line2D, out Vector2D?)" />
     public static bool Intersects(this Line2D left, Line2D right, [NotNullWhen(returnValue: true)] out Vector2D? point) => Line2D.Intersects(left, right, out point);
 
+    /// <inheritdoc cref="Line2D.ClosestPointTo(Line2D, Vector2D)" />
+    public static Vector2D ClosestPointTo(this Line2D line, Vector2D point) => Line2D.ClosestPointTo(line, point);
+
     /// <inheritdoc cref="Line2D.ApproximatelyEquals(Line2D, Line2D, float)" />
     public static bool ApproximatelyEquals(this Line2D left, Line2D right, float epsilon = float.Epsilon) => Line2D.ApproximatelyEquals(left, right, epsilon);
 }

Engine.Core/Primitives/Line2DEquation.cs

@@ -1,47 +1,69 @@
 namespace Syntriax.Engine.Core;
 
 /// <summary>
-/// Represents a line equation in the form y = mx + b.
+/// Represents a <see cref="Line2DEquation"/> in the form y = mx + b.
 /// </summary>
 /// <param name="slope">The slope of the line.</param>
-/// <param name="offsetY">The y-intercept of the line.</param>
+/// <param name="offsetY">The Y intercept of the line.</param>
 /// <remarks>
-/// Initializes a new instance of the <see cref="Line2DEquation"/> struct with the specified slope and y-intercept.
+/// Initializes a new instance of the <see cref="Line2DEquation"/> struct with the specified slope and Y intercept.
 /// </remarks>
 [System.Diagnostics.DebuggerDisplay("y = {Slope}x + {OffsetY}")]
 public readonly struct Line2DEquation(float slope, float offsetY)
 {
     /// <summary>
-    /// The slope of the line equation.
+    /// The slope of the <see cref="Line2DEquation"/>.
     /// </summary>
     public readonly float Slope = slope;
 
     /// <summary>
-    /// The y-intercept of the line equation.
+    /// The Y intercept of the <see cref="Line2DEquation"/>.
     /// </summary>
     public readonly float OffsetY = offsetY;
 
+    public static bool operator ==(Line2DEquation left, Line2DEquation right) => left.Slope == right.Slope && left.OffsetY == right.OffsetY;
+    public static bool operator !=(Line2DEquation left, Line2DEquation right) => left.Slope != right.Slope || left.OffsetY != right.OffsetY;
+
     /// <summary>
-    /// Resolves the y-coordinate for a given x-coordinate using the line equation.
+    /// Resolves the Y coordinate for a given X coordinate using the <see cref="Line2DEquation"/>.
     /// </summary>
-    /// <param name="lineEquation">The line equation to resolve.</param>
-    /// <param name="x">The x-coordinate for which to resolve the y-coordinate.</param>
-    /// <returns>The y-coordinate resolved using the line equation.</returns>
+    /// <param name="lineEquation">The <see cref="Line2DEquation"/> to resolve.</param>
+    /// <param name="x">The X coordinate for which to resolve the Y coordinate.</param>
+    /// <returns>The Y coordinate resolved using the <see cref="Line2DEquation"/>.</returns>
     public static float Resolve(Line2DEquation lineEquation, float x) => lineEquation.Slope * x + lineEquation.OffsetY; // y = mx + b
 
     /// <summary>
-    /// Checks if two line equations are approximately equal.
+    /// Checks if two <see cref="Line2DEquation"/> are approximately equal.
     /// </summary>
-    /// <param name="left">The first line equation to compare.</param>
-    /// <param name="right">The second line equation to compare.</param>
+    /// <param name="left">The first <see cref="Line2DEquation"/> to compare.</param>
+    /// <param name="right">The second <see cref="Line2DEquation"/> to compare.</param>
     /// <param name="epsilon">The epsilon range.</param>
-    /// <returns>True if the line equations are approximately equal; otherwise, false.</returns>
+    /// <returns>True if the <see cref="Line2DEquation"/> are approximately equal; otherwise, false.</returns>
     public static bool ApproximatelyEquals(Line2DEquation left, Line2DEquation right, float epsilon = float.Epsilon)
         => left.Slope.ApproximatelyEquals(right.Slope, epsilon) && left.OffsetY.ApproximatelyEquals(right.OffsetY, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Line2DEquation"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Line2DEquation"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Line2DEquation"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Line2DEquation lineEquation && this == lineEquation;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Line2DEquation"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Line2DEquation"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Slope, OffsetY);
+
+    /// <summary>
+    /// Converts the <see cref="Line2DEquation"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Line2DEquation"/>.</returns>
+    public override string ToString() => $"{nameof(Line2DEquation)}({Slope}, {OffsetY})";
 }
 
 /// <summary>
-/// Provides extension methods for the LineEquation struct.
+/// Provides extension methods for the <see cref="Line2DEquation"/> struct.
 /// </summary>
 public static class Line2DEquationExtensions
 {

Engine.Core/Primitives/Projection1D.cs

@@ -21,6 +21,9 @@ public readonly struct Projection1D(float min, float max)
     /// </summary>
     public readonly float Max = max;
 
+    public static bool operator ==(Projection1D left, Projection1D right) => left.Min == right.Min && left.Max == right.Max;
+    public static bool operator !=(Projection1D left, Projection1D right) => left.Min != right.Min || left.Max != right.Max;
+
     /// <summary>
     /// Checks if two projections overlap.
     /// </summary>
@@ -70,6 +73,35 @@ public readonly struct Projection1D(float min, float max)
         depth = 0f;
         return false;
     }
+
+    /// <summary>
+    /// Checks if two <see cref="Projection1D"/>s are approximately equal within a specified epsilon range.
+    /// </summary>
+    /// <param name="left">The first <see cref="Projection1D"/>.</param>
+    /// <param name="right">The second <see cref="Projection1D"/>.</param>
+    /// <param name="epsilon">The epsilon range.</param>
+    /// <returns><see cref="true"/> if the <see cref="Projection1D"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
+    public static bool ApproximatelyEquals(Projection1D left, Projection1D right, float epsilon = float.Epsilon)
+        => left.Min.ApproximatelyEquals(right.Min, epsilon) && left.Max.ApproximatelyEquals(right.Max, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Projection1D"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Projection1D"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Projection1D"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Projection1D projection1D && this == projection1D;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Projection1D"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Projection1D"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Min, Max);
+
+    /// <summary>
+    /// Converts the <see cref="Projection1D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Projection1D"/>.</returns>
+    public override string ToString() => $"{nameof(Projection1D)}({Min}, {Max})";
 }
 
 /// <summary>
@@ -82,4 +114,7 @@ public static class Projection1DExtensions
 
     /// <inheritdoc cref="Projection1D.Overlaps(Projection1D, Projection1D, out float)" />
     public static bool Overlaps(this Projection1D left, Projection1D right, out float depth) => Projection1D.Overlaps(left, right, out depth);
+
+    /// <inheritdoc cref="Projection1D.ApproximatelyEquals(Projection1D, Projection1D, float)" />
+    public static bool ApproximatelyEquals(this Projection1D left, Projection1D right, float epsilon = float.Epsilon) => Projection1D.ApproximatelyEquals(left, right, epsilon);
 }

Engine.Core/Primitives/Quaternion.cs

@@ -282,24 +282,24 @@ public readonly struct Quaternion(float x, float y, float z, float w)
     public static bool ApproximatelyEquals(Quaternion left, Quaternion right, float epsilon = float.Epsilon)
         => left.X.ApproximatelyEquals(right.X, epsilon) && left.Y.ApproximatelyEquals(right.Y, epsilon) && left.Z.ApproximatelyEquals(right.Z, epsilon) && left.W.ApproximatelyEquals(right.W, epsilon);
 
-    /// <summary>
-    /// Converts the <see cref="Quaternion"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="Quaternion"/>.</returns>
-    public override string ToString() => $"{nameof(Quaternion)}({W}, {X}, {Y}, {Z})";
-
     /// <summary>
     /// Determines whether the specified object is equal to the current <see cref="Quaternion"/>.
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="Quaternion"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Quaternion"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is Quaternion objVec && X.Equals(objVec.X) && Y.Equals(objVec.Y) && Z.Equals(objVec.Z) && W.Equals(objVec.W);
+    public override bool Equals(object? obj) => obj is Quaternion quaternion && this == quaternion;
 
     /// <summary>
     /// Generates a hash code for the <see cref="Quaternion"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="Quaternion"/>.</returns>
-    public override int GetHashCode() => System.HashCode.Combine(X, Y, Z);
+    public override int GetHashCode() => System.HashCode.Combine(W, X, Y, Z);
+
+    /// <summary>
+    /// Converts the <see cref="Quaternion"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Quaternion"/>.</returns>
+    public override string ToString() => $"{nameof(Quaternion)}({W}, {X}, {Y}, {Z})";
 }
 
 /// <summary>

Engine.Core/Primitives/Ray2D.cs

@@ -0,0 +1,105 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents an infinite ray in 2D space.
+/// </summary>
+/// <param name="Origin">The <see cref="Vector2D"/> in 2D space where the ray starts from.</param>
+/// <param name="Direction">Normalized <see cref="Vector2D"/> indicating the ray's is direction.</param> 
+public readonly struct Ray2D(Vector2D Origin, Vector2D Direction)
+{
+    /// <summary>
+    /// The starting point of the <see cref="Ray2D"/>.
+    /// </summary>
+    public readonly Vector2D Origin = Origin;
+
+    /// <summary>
+    /// The direction in which the <see cref="Ray2D"/> points. Should be a normalized vector.
+    /// </summary>
+    public readonly Vector2D Direction = Direction;
+
+    /// <summary>
+    /// Gets a <see cref="Ray2D"/> with the same origin but with the direction reversed.
+    /// </summary>
+    public readonly Ray2D Reversed => new(Origin, -Direction);
+
+    public static bool operator ==(Ray2D left, Ray2D right) => left.Origin == right.Origin && left.Direction == right.Direction;
+    public static bool operator !=(Ray2D left, Ray2D right) => left.Origin != right.Origin || left.Direction != right.Direction;
+    public static implicit operator Ray2D(Line2D line) => new(line.From, line.From.FromTo(line.To).Normalized);
+
+    /// <summary>
+    /// Constructs a <see cref="Line2D"/> from a <see cref="Ray2D"/>, extending from its origin in the <see cref="Ray2D"/>'s direction for a given distance.
+    /// </summary>
+    /// <param name="ray">The source <see cref="Ray2D"/>.</param>
+    /// <param name="distance">The length of the line segment to create from the <see cref="Ray2D"/>.</param>
+    /// <returns>A <see cref="Line2D"/> representing the segment of the <see cref="Ray2D"/>.</returns>
+    public static Line2D GetLine(Ray2D ray, float distance)
+        => new(ray.Origin, ray.Origin + ray.Direction * distance);
+
+    /// <summary>
+    /// Evaluates the point on the <see cref="Ray2D"/> at a specified distance from its origin.
+    /// </summary>
+    /// <param name="ray">The <see cref="Ray2D"/> to evaluate.</param>
+    /// <param name="distanceFromOrigin">The distance from the origin along the <see cref="Ray2D"/>'s direction.</param>
+    /// <returns>A <see cref="Vector2D"/> representing the point at the given distance on the <see cref="Ray2D"/>.</returns>
+    public static Vector2D Evaluate(Ray2D ray, float distanceFromOrigin)
+        => ray.Origin + ray.Direction * distanceFromOrigin;
+
+    /// <summary>
+    /// Calculates the closest point on the <see cref="Ray2D"/> to the specified point.
+    /// </summary>
+    public static Vector2D ClosestPointTo(Ray2D ray, Vector2D point)
+    {
+        Vector2D originToPoint = ray.Origin.FromTo(point);
+
+        float dot = ray.Direction.Dot(originToPoint);
+
+        return ray.Origin + ray.Direction * dot;
+    }
+
+    /// <summary>
+    /// Checks if two <see cref="Ray2D"/>s are approximately equal within a specified epsilon range.
+    /// </summary>
+    /// <param name="left">The first <see cref="Ray2D"/>.</param>
+    /// <param name="right">The second <see cref="Ray2D"/>.</param>
+    /// <param name="epsilon">The epsilon range.</param>
+    /// <returns><see cref="true"/> if the <see cref="Ray2D"/>s are approximately equal; otherwise, <see cref="false"/>.</returns>
+    public static bool ApproximatelyEquals(Ray2D left, Ray2D right, float epsilon = float.Epsilon)
+        => left.Origin.ApproximatelyEquals(right.Origin, epsilon) && left.Direction.ApproximatelyEquals(right.Direction, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Ray2D"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Ray2D"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Ray2D"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Ray2D ray2D && this == ray2D;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Ray2D"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Ray2D"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Origin, Direction);
+
+    /// <summary>
+    /// Converts the <see cref="Ray2D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Ray2D"/>.</returns>
+    public override string ToString() => $"{nameof(Ray2D)}({Origin}, {Direction})";
+}
+
+/// <summary>
+/// Provides extension methods for the <see cref="Ray2D"/> struct.
+/// </summary>
+public static class Ray2DExtensions
+{
+    /// <inheritdoc cref="Ray2D.GetLine(Ray2D, float) />
+    public static Line2D ToLine(this Ray2D ray, float distance) => Ray2D.GetLine(ray, distance);
+
+    /// <inheritdoc cref="Ray2D.Evaluate(Ray2D, float) />
+    public static Vector2D Evaluate(this Ray2D ray, float distanceFromOrigin) => Ray2D.Evaluate(ray, distanceFromOrigin);
+
+    /// <inheritdoc cref="Ray2D.ClosestPointTo(Ray2D, Vector2D) />
+    public static Vector2D ClosestPointTo(this Ray2D ray, Vector2D point) => Ray2D.ClosestPointTo(ray, point);
+
+    /// <inheritdoc cref="Ray2D.ApproximatelyEquals(Ray2D, Ray2D, float)" />
+    public static bool ApproximatelyEquals(this Ray2D left, Ray2D right, float epsilon = float.Epsilon) => Ray2D.ApproximatelyEquals(left, right, epsilon);
+}

Engine.Core/Primitives/Shape2D.cs

@@ -18,7 +18,7 @@ public class Shape2D(List<Vector2D> vertices) : IEnumerable<Vector2D>
     public static Shape2D Pentagon => CreateNgon(5, Vector2D.Up);
     public static Shape2D Hexagon => CreateNgon(6, Vector2D.Right);
 
-    public event ShapeUpdatedEventHandler? OnShapeUpdated = null;
+    public Event<Shape2D> OnShapeUpdated { get; } = new();
 
     private List<Vector2D> _vertices = vertices;
 
@@ -35,7 +35,7 @@ public class Shape2D(List<Vector2D> vertices) : IEnumerable<Vector2D>
             foreach (Vector2D vertex in value)
                 _vertices.Add(vertex);
 
-            OnShapeUpdated?.InvokeSafe(this);
+            OnShapeUpdated?.Invoke(this);
         }
     }
 
@@ -122,7 +122,7 @@ public class Shape2D(List<Vector2D> vertices) : IEnumerable<Vector2D>
         triangles.Clear();
 
         for (int i = 2; i < shape.Vertices.Count; i++)
-            triangles.Add(new Triangle(shape[0], shape[i - 1], shape[i]));
+            triangles.Add(new Triangle(shape[0], shape[i], shape[i - 1]));
     }
 
     /// <summary>
@@ -229,7 +229,7 @@ public class Shape2D(List<Vector2D> vertices) : IEnumerable<Vector2D>
         for (int i = 0; i < count; i++)
             to._vertices.Add(transform.Transform(from[i]));
 
-        to.OnShapeUpdated?.InvokeSafe(to);
+        to.OnShapeUpdated?.Invoke(to);
     }
 
     /// <summary>
@@ -251,13 +251,39 @@ public class Shape2D(List<Vector2D> vertices) : IEnumerable<Vector2D>
         return true;
     }
 
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Shape2D"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Shape2D"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Shape2D"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Shape2D shape2D && _vertices.Equals(shape2D._vertices);
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Shape2D"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Shape2D"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(Vertices);
+
+    /// <summary>
+    /// Converts the <see cref="Shape2D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Shape2D"/>.</returns>
+    public override string ToString()
+    {
+        System.Text.StringBuilder stringBuilder = new(Vertices[0].ToString());
+        for (int i = 1; i < Vertices.Count; i++)
+        {
+            stringBuilder.Append(", ");
+            stringBuilder.Append(Vertices[i].ToString());
+        }
+        return $"{nameof(Shape2D)}({stringBuilder})";
+    }
+
     /// <inheritdoc/>
     public IEnumerator<Vector2D> GetEnumerator() => Vertices.GetEnumerator();
 
     /// <inheritdoc/>
     IEnumerator IEnumerable.GetEnumerator() => Vertices.GetEnumerator();
-
-    public delegate void ShapeUpdatedEventHandler(Shape2D shape2D);
 }
 
 /// <summary>
@@ -272,7 +298,7 @@ public static class Shape2DExtensions
     public static Triangle ToSuperTriangle(this Shape2D shape) => Shape2D.GetSuperTriangle(shape);
 
     /// <inheritdoc cref="Shape2D.TriangulateConvex(Shape2D, IList{Triangle})" />
-    public static void ToTrianglesConvex(this Shape2D shape, IList<Triangle> lines) => Shape2D.TriangulateConvex(shape, lines);
+    public static void ToTrianglesConvex(this Shape2D shape, IList<Triangle> triangles) => Shape2D.TriangulateConvex(shape, triangles);
 
     /// <inheritdoc cref="Shape2D.TriangulateConvex(Shape2D)" />
     public static List<Triangle> ToTrianglesConvex(this Shape2D shape) => Shape2D.TriangulateConvex(shape);

Engine.Core/Primitives/Triangle.cs

@@ -7,6 +7,9 @@ public readonly struct Triangle(Vector2D A, Vector2D B, Vector2D C)
     public readonly Vector2D B { get; init; } = B;
     public readonly Vector2D C { get; init; } = C;
 
+    public static bool operator ==(Triangle left, Triangle right) => left.A == right.A && left.B == right.B && left.C == right.C;
+    public static bool operator !=(Triangle left, Triangle right) => left.A != right.A || left.B != right.B || left.C != right.C;
+
     public readonly float Area
         => .5f * Math.Abs(
                 A.X * (B.Y - C.Y) +
@@ -44,6 +47,25 @@ public readonly struct Triangle(Vector2D A, Vector2D B, Vector2D C)
     /// <returns><c>true</c> if the <see cref="Triangle"/>s are approximately equal; otherwise, <c>false</c>.</returns>
     public static bool ApproximatelyEquals(Triangle left, Triangle right, float epsilon = float.Epsilon)
         => left.A.ApproximatelyEquals(right.A, epsilon) && left.B.ApproximatelyEquals(right.B, epsilon) && left.C.ApproximatelyEquals(right.C, epsilon);
+
+    /// <summary>
+    /// Determines whether the specified object is equal to the current <see cref="Triangle"/>.
+    /// </summary>
+    /// <param name="obj">The object to compare with the current <see cref="Triangle"/>.</param>
+    /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Triangle"/>; otherwise, <see cref="false"/>.</returns>
+    public override bool Equals(object? obj) => obj is Triangle triangle && this == triangle;
+
+    /// <summary>
+    /// Generates a hash code for the <see cref="Triangle"/>.
+    /// </summary>
+    /// <returns>A hash code for the <see cref="Triangle"/>.</returns>
+    public override int GetHashCode() => System.HashCode.Combine(A, B, C);
+
+    /// <summary>
+    /// Converts the <see cref="Triangle"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Triangle"/>.</returns>
+    public override string ToString() => $"{nameof(Triangle)}({A}, {B}, {C})";
 }
 
 public static class TriangleExtensions

Engine.Core/Primitives/Vector2D.cs

@@ -31,6 +31,11 @@ public readonly struct Vector2D(float x, float y)
     /// </summary>
     public float MagnitudeSquared => LengthSquared(this);
 
+    /// <summary>
+    /// Gets a <see cref="Vector2D"/> with the direction reversed.
+    /// </summary>
+    public readonly Vector2D Reversed => -this;
+
     /// <summary>
     /// The normalized form of the <see cref="Vector2D"/> (a <see cref="Vector2D"/> with the same direction and a magnitude of 1).
     /// </summary>
@@ -297,24 +302,24 @@ public readonly struct Vector2D(float x, float y)
     public static bool ApproximatelyEquals(Vector2D left, Vector2D right, float epsilon = float.Epsilon)
         => left.X.ApproximatelyEquals(right.X, epsilon) && left.Y.ApproximatelyEquals(right.Y, epsilon);
 
-    /// <summary>
-    /// Converts the <see cref="Vector2D"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="Vector2D"/>.</returns>
-    public override string ToString() => $"{nameof(Vector2D)}({X}, {Y})";
-
     /// <summary>
     /// Determines whether the specified object is equal to the current <see cref="Vector2D"/>.
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="Vector2D"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Vector2D"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is Vector2D objVec && X.Equals(objVec.X) && Y.Equals(objVec.Y);
+    public override bool Equals(object? obj) => obj is Vector2D vector2D && this == vector2D;
 
     /// <summary>
     /// Generates a hash code for the <see cref="Vector2D"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="Vector2D"/>.</returns>
     public override int GetHashCode() => System.HashCode.Combine(X, Y);
+
+    /// <summary>
+    /// Converts the <see cref="Vector2D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Vector2D"/>.</returns>
+    public override string ToString() => $"{nameof(Vector2D)}({X}, {Y})";
 }
 
 /// <summary>

Engine.Core/Primitives/Vector3D.cs

@@ -271,24 +271,24 @@ public readonly struct Vector3D(float x, float y, float z)
     public static bool ApproximatelyEquals(Vector3D left, Vector3D right, float epsilon = float.Epsilon)
         => left.X.ApproximatelyEquals(right.X, epsilon) && left.Y.ApproximatelyEquals(right.Y, epsilon) && left.Z.ApproximatelyEquals(right.Z, epsilon);
 
-    /// <summary>
-    /// Converts the <see cref="Vector3D"/> to its string representation.
-    /// </summary>
-    /// <returns>A string representation of the <see cref="Vector3D"/>.</returns>
-    public override string ToString() => $"{nameof(Vector3D)}({X}, {Y}, {Z})";
-
     /// <summary>
     /// Determines whether the specified object is equal to the current <see cref="Vector3D"/>.
     /// </summary>
     /// <param name="obj">The object to compare with the current <see cref="Vector3D"/>.</param>
     /// <returns><see cref="true"/> if the specified object is equal to the current <see cref="Vector3D"/>; otherwise, <see cref="false"/>.</returns>
-    public override bool Equals(object? obj) => obj is Vector3D objVec && X.Equals(objVec.X) && Y.Equals(objVec.Y) && Z.Equals(objVec.Z);
+    public override bool Equals(object? obj) => obj is Vector3D vector3D && this == vector3D;
 
     /// <summary>
     /// Generates a hash code for the <see cref="Vector3D"/>.
     /// </summary>
     /// <returns>A hash code for the <see cref="Vector3D"/>.</returns>
     public override int GetHashCode() => System.HashCode.Combine(X, Y, Z);
+
+    /// <summary>
+    /// Converts the <see cref="Vector3D"/> to its string representation.
+    /// </summary>
+    /// <returns>A string representation of the <see cref="Vector3D"/>.</returns>
+    public override string ToString() => $"{nameof(Vector3D)}({X}, {Y}, {Z})";
 }
 
 /// <summary>

Engine.Core/Serialization/EntityRegistry.cs

@@ -5,7 +5,7 @@ namespace Syntriax.Engine.Core.Serialization;
 
 public class EntityRegistry
 {
-    public event EntityRegisteredEventHandler? OnEntityRegistered = null!;
+    public Event<EntityRegistry, EntityRegisteredArguments> OnEntityRegistered = null!;
 
     private readonly Dictionary<string, Action<IEntity>?> assignCallbacks = [];
     private readonly Dictionary<string, IEntity> registeredEntities = [];
@@ -14,7 +14,7 @@ public class EntityRegistry
     public void Add(IEntity entity)
     {
         if (registeredEntities.TryAdd(entity.Id, entity))
-            OnEntityRegistered?.InvokeSafe(this, entity);
+            OnEntityRegistered?.Invoke(this, new(entity));
     }
 
     public void QueueAssign(string id, Action<IEntity> setMethod)
@@ -26,7 +26,7 @@ public class EntityRegistry
     public void AssignAll()
     {
         foreach ((string id, Action<IEntity>? action) in assignCallbacks)
-            action?.InvokeSafe(registeredEntities[id]);
+            action?.Invoke(registeredEntities[id]);
     }
 
     public void Reset()
@@ -35,5 +35,5 @@ public class EntityRegistry
         registeredEntities.Clear();
     }
 
-    public delegate void EntityRegisteredEventHandler(EntityRegistry sender, IEntity entity);
+    public readonly record struct EntityRegisteredArguments(IEntity Entity);
 }

Engine.Core/StateEnable.cs

@@ -2,9 +2,9 @@ namespace Syntriax.Engine.Core;
 
 public class StateEnable : IStateEnable
 {
-    public event IAssignable.UnassignEventHandler? OnUnassigned = null;
-    public event IHasEntity.EntityAssignedEventHandler? OnEntityAssigned = null;
-    public event IStateEnable.EnabledChangedEventHandler? OnEnabledChanged = null;
+    public Event<IStateEnable, IStateEnable.EnabledChangedArguments> OnEnabledChanged { get; } = new();
+    public Event<IHasEntity> OnEntityAssigned { get; } = new();
+    public Event<IAssignable>? OnUnassigned { get; } = new();
 
     private bool _enabled = true;
     private IEntity _entity = null!;
@@ -21,7 +21,7 @@ public class StateEnable : IStateEnable
 
             bool previousState = _enabled;
             _enabled = value;
-            OnEnabledChanged?.InvokeSafe(this, previousState);
+            OnEnabledChanged?.Invoke(this, new(previousState));
         }
     }
 
@@ -33,7 +33,7 @@ public class StateEnable : IStateEnable
 
         _entity = entity;
         OnAssign(entity);
-        OnEntityAssigned?.InvokeSafe(this);
+        OnEntityAssigned?.Invoke(this);
         return true;
     }
 
@@ -43,7 +43,7 @@ public class StateEnable : IStateEnable
             return false;
 
         _entity = null!;
-        OnUnassigned?.InvokeSafe(this);
+        OnUnassigned?.Invoke(this);
         return true;
     }
 }

Engine.Core/Systems/Abstract/IDraw.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified when the draw phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IDraw : IBehaviour
+{
+    /// <summary>
+    /// Calls draw logic for the <see cref="IBehaviour"/> to be displayed visually.
+    /// </summary>
+    void Draw();
+}

Engine.Core/Systems/Abstract/IEnterUniverse.cs

@@ -0,0 +1,6 @@
+namespace Syntriax.Engine.Core;
+
+public interface IEnterUniverse : IBehaviour
+{
+    void EnterUniverse(IUniverse universe);
+}

Engine.Core/Systems/Abstract/IExitUniverse.cs

@@ -0,0 +1,6 @@
+namespace Syntriax.Engine.Core;
+
+public interface IExitUniverse : IBehaviour
+{
+    void ExitUniverse(IUniverse universe);
+}

Engine.Core/Systems/Abstract/IFirstFrameUpdate.cs

@@ -0,0 +1,6 @@
+namespace Syntriax.Engine.Core;
+
+public interface IFirstFrameUpdate : IBehaviour
+{
+    void FirstActiveFrame();
+}

Engine.Core/Systems/Abstract/ILastFrameUpdate.cs

@@ -0,0 +1,6 @@
+namespace Syntriax.Engine.Core;
+
+public interface ILastFrameUpdate : IBehaviour
+{
+    void LastActiveFrame();
+}

Engine.Core/Systems/Abstract/IPostDraw.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified after the draw phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IPostDraw : IBehaviour
+{
+    /// <summary>
+    /// Updates the state of the <see cref="IBehaviour"/> after the main draw phase happens.
+    /// </summary>
+    void PostDraw();
+}

Engine.Core/Systems/Abstract/IPostUpdate.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified after the update phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IPostUpdate : IBehaviour
+{
+    /// <summary>
+    /// Updates the state of the <see cref="IBehaviour"/> after the main update phase happens.
+    /// </summary>
+    void PostUpdate();
+}

Engine.Core/Systems/Abstract/IPreDraw.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified before the draw phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IPreDraw : IBehaviour
+{
+    /// <summary>
+    /// Updates the state of the <see cref="IBehaviour"/> before the main draw phase happens.
+    /// </summary>
+    void PreDraw();
+}

Engine.Core/Systems/Abstract/IPreUpdate.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified before the update phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IPreUpdate : IBehaviour
+{
+    /// <summary>
+    /// Updates the state of the <see cref="IBehaviour"/> before the main update phase happens.
+    /// </summary>
+    void PreUpdate();
+}

Engine.Core/Systems/Abstract/IUpdate.cs

@@ -0,0 +1,12 @@
+namespace Syntriax.Engine.Core;
+
+/// <summary>
+/// Represents a <see cref="IBehaviour"/> to be notified when the update phase of the <see cref="IUniverse"/> occurs.
+/// </summary>
+public interface IUpdate : IBehaviour
+{
+    /// <summary>
+    /// Updates the state of the <see cref="IBehaviour"/>.
+    /// </summary>
+    void Update();
+}

Engine.Core/Systems/DrawManager.cs

@@ -0,0 +1,53 @@
+using System.Collections.Generic;
+
+namespace Syntriax.Engine.Core;
+
+public class DrawManager : Behaviour
+{
+    // We use Descending order because draw calls are running from last to first
+    private static Comparer<IBehaviour> SortByDescendingPriority() => Comparer<IBehaviour>.Create((x, y) => y.Priority.CompareTo(x.Priority));
+
+    private readonly ActiveBehaviourCollectorSorted<IPreDraw> preDrawEntities = new() { SortBy = SortByDescendingPriority() };
+    private readonly ActiveBehaviourCollectorSorted<IDraw> drawEntities = new() { SortBy = SortByDescendingPriority() };
+    private readonly ActiveBehaviourCollectorSorted<IPostDraw> postDrawEntities = new() { SortBy = SortByDescendingPriority() };
+
+    private void OnPreDraw(IUniverse sender)
+    {
+        for (int i = preDrawEntities.Count - 1; i >= 0; i--)
+            preDrawEntities[i].PreDraw();
+    }
+
+    private void OnDraw(IUniverse sender)
+    {
+        for (int i = drawEntities.Count - 1; i >= 0; i--)
+            drawEntities[i].Draw();
+    }
+
+    private void OnPostDraw(IUniverse sender)
+    {
+        for (int i = postDrawEntities.Count - 1; i >= 0; i--)
+            postDrawEntities[i].PostDraw();
+    }
+
+    protected override void OnEnteredUniverse(IUniverse universe)
+    {
+        preDrawEntities.Assign(universe);
+        drawEntities.Assign(universe);
+        postDrawEntities.Assign(universe);
+
+        universe.OnPreDraw.AddListener(OnPreDraw);
+        universe.OnDraw.AddListener(OnDraw);
+        universe.OnPostDraw.AddListener(OnPostDraw);
+    }
+
+    protected override void OnExitedUniverse(IUniverse universe)
+    {
+        preDrawEntities.Unassign();
+        drawEntities.Unassign();
+        postDrawEntities.Unassign();
+
+        universe.OnPreDraw.RemoveListener(OnPreDraw);
+        universe.OnDraw.RemoveListener(OnDraw);
+        universe.OnPostDraw.RemoveListener(OnPostDraw);
+    }
+}

Engine.Core/Systems/UniverseEntranceManager.cs

@@ -0,0 +1,71 @@
+using System.Collections.Generic;
+
+namespace Syntriax.Engine.Core;
+
+public class UniverseEntranceManager : Behaviour
+{
+    // We use Ascending order because we are using reverse for loop to call them
+    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private readonly ActiveBehaviourCollectorSorted<IEnterUniverse> enterUniverses = new() { SortBy = SortByAscendingPriority() };
+    private readonly ActiveBehaviourCollectorSorted<IExitUniverse> exitUniverses = new() { SortBy = SortByAscendingPriority() };
+
+    private readonly List<IEnterUniverse> toCallEnterUniverses = new(32);
+    private readonly List<IExitUniverse> toCallExitUniverses = new(32);
+
+    protected override void OnEnteredUniverse(IUniverse universe)
+    {
+        enterUniverses.Assign(universe);
+
+        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
+            OnUniverseObjectRegistered(Universe, new(universeObject));
+
+        universe.OnUniverseObjectRegistered.AddListener(OnUniverseObjectRegistered);
+        universe.OnUniverseObjectUnRegistered.AddListener(OnUniverseObjectUnRegistered);
+    }
+
+    protected override void OnExitedUniverse(IUniverse universe)
+    {
+        enterUniverses.Unassign();
+
+        foreach (IUniverseObject universeObject in Universe.UniverseObjects)
+            OnUniverseObjectUnRegistered(Universe, new(universeObject));
+
+        universe.OnUniverseObjectRegistered.RemoveListener(OnUniverseObjectRegistered);
+        universe.OnUniverseObjectUnRegistered.RemoveListener(OnUniverseObjectUnRegistered);
+    }
+
+    private void OnUniverseObjectUnRegistered(IUniverse sender, IUniverse.UniverseObjectUnRegisteredArguments args)
+    {
+        for (int i = toCallExitUniverses.Count - 1; i >= 0; i--)
+        {
+            toCallExitUniverses[i].ExitUniverse(Universe);
+            toCallExitUniverses.RemoveAt(i);
+        }
+    }
+
+    private void OnUniverseObjectRegistered(IUniverse sender, IUniverse.UniverseObjectRegisteredArguments args)
+    {
+        for (int i = toCallEnterUniverses.Count - 1; i >= 0; i--)
+        {
+            toCallEnterUniverses[i].EnterUniverse(Universe);
+            toCallEnterUniverses.RemoveAt(i);
+        }
+    }
+
+    private void OnEnterUniverseCollected(IBehaviourCollector<IEnterUniverse> sender, IBehaviourCollector<IEnterUniverse>.BehaviourCollectedArguments args)
+    {
+        toCallEnterUniverses.Add(args.BehaviourCollected);
+    }
+
+    private void OnExitUniverseCollected(IBehaviourCollector<IExitUniverse> sender, IBehaviourCollector<IExitUniverse>.BehaviourCollectedArguments args)
+    {
+        toCallExitUniverses.Add(args.BehaviourCollected);
+    }
+
+    public UniverseEntranceManager()
+    {
+        enterUniverses.OnCollected.AddListener(OnEnterUniverseCollected);
+        exitUniverses.OnCollected.AddListener(OnExitUniverseCollected);
+    }
+}

Engine.Core/Systems/UpdateManager.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+
+namespace Syntriax.Engine.Core;
+
+public class UpdateManager : Behaviour
+{
+    // We use Ascending order because we are using reverse for loop to call them
+    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private readonly ActiveBehaviourCollectorSorted<IFirstFrameUpdate> firstFrameUpdates = new() { SortBy = SortByAscendingPriority() };
+    private readonly ActiveBehaviourCollector<ILastFrameUpdate> lastFrameUpdates = new();
+    private readonly ActiveBehaviourCollectorSorted<IPreUpdate> preUpdateEntities = new() { SortBy = SortByAscendingPriority() };
+    private readonly ActiveBehaviourCollectorSorted<IUpdate> updateEntities = new() { SortBy = SortByAscendingPriority() };
+    private readonly ActiveBehaviourCollectorSorted<IPostUpdate> postUpdateEntities = new() { SortBy = SortByAscendingPriority() };
+
+    private readonly List<IFirstFrameUpdate> toCallFirstFrameUpdates = new(32);
+
+    protected override void OnEnteredUniverse(IUniverse universe)
+    {
+        firstFrameUpdates.Assign(universe);
+        lastFrameUpdates.Assign(universe);
+        preUpdateEntities.Assign(universe);
+        updateEntities.Assign(universe);
+        postUpdateEntities.Assign(universe);
+
+        universe.OnPreUpdate.AddListener(OnPreUpdate);
+        universe.OnUpdate.AddListener(OnUpdate);
+        universe.OnPostUpdate.AddListener(OnPostUpdate);
+    }
+
+    protected override void OnExitedUniverse(IUniverse universe)
+    {
+        firstFrameUpdates.Unassign();
+        lastFrameUpdates.Unassign();
+        preUpdateEntities.Unassign();
+        updateEntities.Unassign();
+        postUpdateEntities.Unassign();
+
+        universe.OnPreUpdate.RemoveListener(OnPreUpdate);
+        universe.OnUpdate.RemoveListener(OnUpdate);
+        universe.OnPostUpdate.RemoveListener(OnPostUpdate);
+    }
+
+    private void OnPreUpdate(IUniverse sender, IUniverse.UpdateArguments args)
+    {
+        for (int i = toCallFirstFrameUpdates.Count - 1; i >= 0; i--)
+        {
+            toCallFirstFrameUpdates[i].FirstActiveFrame();
+            toCallFirstFrameUpdates.RemoveAt(i);
+        }
+
+        for (int i = preUpdateEntities.Count - 1; i >= 0; i--)
+            preUpdateEntities[i].PreUpdate();
+    }
+
+    private void OnUpdate(IUniverse sender, IUniverse.UpdateArguments args)
+    {
+        for (int i = updateEntities.Count - 1; i >= 0; i--)
+            updateEntities[i].Update();
+    }
+
+    private void OnPostUpdate(IUniverse sender, IUniverse.UpdateArguments args)
+    {
+        for (int i = postUpdateEntities.Count - 1; i >= 0; i--)
+            postUpdateEntities[i].PostUpdate();
+    }
+
+    private void OnFirstFrameCollected(IBehaviourCollector<IFirstFrameUpdate> sender, IBehaviourCollector<IFirstFrameUpdate>.BehaviourCollectedArguments args)
+    {
+        toCallFirstFrameUpdates.Add(args.BehaviourCollected);
+    }
+
+    private void OnLastFrameRemoved(IBehaviourCollector<ILastFrameUpdate> sender, IBehaviourCollector<ILastFrameUpdate>.BehaviourRemovedArguments args)
+    {
+        args.BehaviourRemoved.LastActiveFrame();
+    }
+
+    public UpdateManager()
+    {
+        firstFrameUpdates.OnCollected.AddListener(OnFirstFrameCollected);
+        lastFrameUpdates.OnRemoved.AddListener(OnLastFrameRemoved);
+    }
+}

Engine.Core/Transform2D.cs

@@ -5,9 +5,9 @@ namespace Syntriax.Engine.Core;
 [System.Diagnostics.DebuggerDisplay("Name: {UniverseObject.Name, nq} Position: {Position.ToString(), nq}, Scale: {Scale.ToString(), nq}, Rotation: {Rotation}")]
 public class Transform2D : Behaviour, ITransform2D
 {
-    public event ITransform2D.PositionChangedEventHandler? OnPositionChanged = null;
-    public event ITransform2D.ScaleChangedEventHandler? OnScaleChanged = null;
-    public event ITransform2D.RotationChangedEventHandler? OnRotationChanged = null;
+    public Event<ITransform2D, ITransform2D.PositionChangedArguments> OnPositionChanged { get; } = new();
+    public Event<ITransform2D, ITransform2D.ScaleChangedArguments> OnScaleChanged { get; } = new();
+    public Event<ITransform2D, ITransform2D.RotationChangedArguments> OnRotationChanged { get; } = new();
 
     private Vector2D _position = Vector2D.Zero;
     private Vector2D _scale = Vector2D.One;
@@ -19,6 +19,11 @@ public class Transform2D : Behaviour, ITransform2D
 
     private ITransform2D? parentTransform = null;
 
+    public Vector2D Up => Vector2D.Up.Rotate(Rotation * Math.DegreeToRadian);
+    public Vector2D Down => Vector2D.Down.Rotate(Rotation * Math.DegreeToRadian);
+    public Vector2D Left => Vector2D.Left.Rotate(Rotation * Math.DegreeToRadian);
+    public Vector2D Right => Vector2D.Right.Rotate(Rotation * Math.DegreeToRadian);
+
     public Vector2D Position
     {
         get => _position;
@@ -31,7 +36,7 @@ public class Transform2D : Behaviour, ITransform2D
             _position = value;
 
             UpdateLocalPosition();
-            OnPositionChanged?.InvokeSafe(this, previousPosition);
+            OnPositionChanged?.Invoke(this, new(previousPosition));
         }
     }
 
@@ -47,7 +52,7 @@ public class Transform2D : Behaviour, ITransform2D
             _scale = value;
 
             UpdateLocalScale();
-            OnScaleChanged?.InvokeSafe(this, previousScale);
+            OnScaleChanged?.Invoke(this, new(previousScale));
         }
     }
 
@@ -63,7 +68,7 @@ public class Transform2D : Behaviour, ITransform2D
             _rotation = value;
 
             UpdateLocalRotation();
-            OnRotationChanged?.InvokeSafe(this, previousRotation);
+            OnRotationChanged?.Invoke(this, new(previousRotation));
         }
     }
 
@@ -79,7 +84,7 @@ public class Transform2D : Behaviour, ITransform2D
             _localPosition = value;
 
             UpdatePosition();
-            OnPositionChanged?.InvokeSafe(this, previousPosition);
+            OnPositionChanged?.Invoke(this, new(previousPosition));
         }
     }
 
@@ -97,8 +102,8 @@ public class Transform2D : Behaviour, ITransform2D
 
             UpdateScale();
             UpdatePosition();
-            OnScaleChanged?.InvokeSafe(this, previousScale);
-            OnPositionChanged?.InvokeSafe(this, previousPosition);
+            OnScaleChanged?.Invoke(this, new(previousScale));
+            OnPositionChanged?.Invoke(this, new(previousPosition));
         }
     }
 
@@ -114,21 +119,21 @@ public class Transform2D : Behaviour, ITransform2D
             _localRotation = value;
 
             UpdateRotation();
-            OnRotationChanged?.InvokeSafe(this, previousRotation);
+            OnRotationChanged?.Invoke(this, new(previousRotation));
         }
     }
 
-    private void RecalculatePosition(ITransform2D _, Vector2D previousPosition)
+    private void RecalculatePosition(ITransform2D _, ITransform2D.PositionChangedArguments args)
     {
         if (parentTransform is null)
             return;
 
         UpdatePosition();
 
-        OnPositionChanged?.InvokeSafe(this, previousPosition);
+        OnPositionChanged?.Invoke(this, args);
     }
 
-    private void RecalculateScale(ITransform2D _, Vector2D previousScale)
+    private void RecalculateScale(ITransform2D _, ITransform2D.ScaleChangedArguments args)
     {
         if (parentTransform is null)
             return;
@@ -138,11 +143,11 @@ public class Transform2D : Behaviour, ITransform2D
         UpdateScale();
         UpdatePosition();
 
-        OnScaleChanged?.InvokeSafe(this, previousScale);
-        OnPositionChanged?.InvokeSafe(this, previousPosition);
+        OnScaleChanged?.Invoke(this, args);
+        OnPositionChanged?.Invoke(this, new(previousPosition));
     }
 
-    private void RecalculateRotation(ITransform2D _, float previousRotation)
+    private void RecalculateRotation(ITransform2D _, ITransform2D.RotationChangedArguments args)
     {
         if (parentTransform is null)
             return;
@@ -152,8 +157,8 @@ public class Transform2D : Behaviour, ITransform2D
         UpdateRotation();
         UpdatePosition();
 
-        OnRotationChanged?.InvokeSafe(this, previousRotation);
-        OnPositionChanged?.InvokeSafe(this, previousPosition);
+        OnRotationChanged?.Invoke(this, args);
+        OnPositionChanged?.Invoke(this, new(previousPosition));
     }
 
     private void UpdateLocalPosition()
@@ -207,12 +212,12 @@ public class Transform2D : Behaviour, ITransform2D
     protected override void InitializeInternal()
     {
         UpdateReferences(UniverseObject.Parent);
-        UniverseObject.OnParentChanged += OnParentChanged;
+        UniverseObject.OnParentChanged.AddListener(OnParentChanged);
     }
 
     protected override void FinalizeInternal()
     {
-        UniverseObject.OnParentChanged -= OnParentChanged;
+        UniverseObject.OnParentChanged.RemoveListener(OnParentChanged);
     }
 
     private void UpdateReferences(IUniverseObject? parent)
@@ -220,48 +225,48 @@ public class Transform2D : Behaviour, ITransform2D
         ITransform2D? previousParent = parentTransform;
         if (previousParent is not null)
         {
-            previousParent.OnPositionChanged -= RecalculatePosition;
-            previousParent.OnScaleChanged -= RecalculateScale;
-            previousParent.OnRotationChanged -= RecalculateRotation;
-            previousParent.BehaviourController.UniverseObject.OnParentChanged -= OnParentChanged;
-            previousParent.BehaviourController.OnBehaviourAdded -= LookForTransform2D;
+            previousParent.OnPositionChanged.RemoveListener(RecalculatePosition);
+            previousParent.OnScaleChanged.RemoveListener(RecalculateScale);
+            previousParent.OnRotationChanged.RemoveListener(RecalculateRotation);
+            previousParent.BehaviourController.UniverseObject.OnParentChanged.RemoveListener(OnParentChanged);
+            previousParent.BehaviourController.OnBehaviourAdded.RemoveListener(LookForTransform2D);
         }
 
         parentTransform = parent?.BehaviourController.GetBehaviour<ITransform2D>();
 
         if (parentTransform is not null)
         {
-            parentTransform.OnPositionChanged += RecalculatePosition;
-            parentTransform.OnScaleChanged += RecalculateScale;
-            parentTransform.OnRotationChanged += RecalculateRotation;
-            parentTransform.BehaviourController.UniverseObject.OnParentChanged += OnParentChanged;
+            parentTransform.OnPositionChanged.AddListener(RecalculatePosition);
+            parentTransform.OnScaleChanged.AddListener(RecalculateScale);
+            parentTransform.OnRotationChanged.AddListener(RecalculateRotation);
+            parentTransform.BehaviourController.UniverseObject.OnParentChanged.AddListener(OnParentChanged);
 
             UpdatePosition();
             UpdateScale();
             UpdateRotation();
         }
         else if (UniverseObject.Parent is not null)
-            UniverseObject.Parent.BehaviourController.OnBehaviourAdded += LookForTransform2D;
+            UniverseObject.Parent.BehaviourController.OnBehaviourAdded.AddListener(LookForTransform2D);
 
         UpdateLocalPosition();
         UpdateLocalScale();
         UpdateLocalRotation();
 
-        OnPositionChanged?.InvokeSafe(this, Position);
-        OnScaleChanged?.InvokeSafe(this, Scale);
-        OnRotationChanged?.InvokeSafe(this, Rotation);
+        OnPositionChanged?.Invoke(this, new(Position));
+        OnScaleChanged?.Invoke(this, new(Scale));
+        OnRotationChanged?.Invoke(this, new(Rotation));
     }
 
-    private void LookForTransform2D(IBehaviourController sender, IBehaviour behaviourAdded)
+    private void LookForTransform2D(IBehaviourController sender, IBehaviourController.BehaviourAddedArguments args)
     {
-        if (behaviourAdded is not ITransform2D transform2D)
+        if (args.BehaviourAdded is not ITransform2D)
             return;
 
         UpdateReferences(UniverseObject.Parent);
     }
 
-    private void OnParentChanged(IUniverseObject sender, IUniverseObject? previousParent, IUniverseObject? newParent)
+    private void OnParentChanged(IUniverseObject sender, IUniverseObject.ParentChangedArguments args)
     {
-        UpdateReferences(newParent);
+        UpdateReferences(args.CurrentParent);
     }
 }

Engine.Core/Universe.cs

@@ -7,18 +7,30 @@ namespace Syntriax.Engine.Core;
 [System.Diagnostics.DebuggerDisplay("UniverseObject Count: {_universeObjects.Count}")]
 public class Universe : BaseEntity, IUniverse
 {
-    public event IUniverse.UpdateEventHandler? OnPreUpdate = null;
-    public event IUniverse.UpdateEventHandler? OnUpdate = null;
-    public event IUniverse.PreDrawEventHandler? OnPreDraw = null;
+    public Event<IUniverse, IUniverse.UpdateArguments> OnPreUpdate { get; } = new();
+    public Event<IUniverse, IUniverse.UpdateArguments> OnUpdate { get; } = new();
+    public Event<IUniverse, IUniverse.UpdateArguments> OnPostUpdate { get; } = new();
+    public Event<IUniverse> OnPreDraw { get; } = new();
+    public Event<IUniverse> OnDraw { get; } = new();
+    public Event<IUniverse> OnPostDraw { get; } = new();
+    public Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments> OnPreUniverseObjectRegistered { get; } = new();
+    public Event<IUniverse, IUniverse.UniverseObjectRegisteredArguments> OnUniverseObjectRegistered { get; } = new();
+    public Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments> OnPreUniverseObjectUnRegistered { get; } = new();
+    public Event<IUniverse, IUniverse.UniverseObjectUnRegisteredArguments> OnUniverseObjectUnRegistered { get; } = new();
+    public Event<IUniverse, IUniverse.TimeScaleChangedArguments> OnTimeScaleChanged { get; } = new();
 
-    public event IUniverse.UniverseObjectRegisteredEventHandler? OnUniverseObjectRegistered = null;
-    public event IUniverse.UniverseObjectUnRegisteredEventHandler? OnUniverseObjectUnRegistered = null;
-
-    public event IUniverse.TimeScaleChangedEventHandler? OnTimeScaleChanged = null;
+    private readonly Event<IInitializable>.EventHandler delegateOnUniverseObjectFinalize = null!;
+    private readonly Event<IUniverseObject, IUniverseObject.ExitedUniverseArguments>.EventHandler delegateOnUniverseObjectExitedUniverse = null!;
 
     private readonly List<IUniverseObject> _universeObjects = new(Constants.UNIVERSE_OBJECTS_SIZE_INITIAL);
     private float _timeScale = 1f;
 
+    public Universe()
+    {
+        delegateOnUniverseObjectFinalize = OnUniverseObjectFinalize;
+        delegateOnUniverseObjectExitedUniverse = OnUniverseObjectExitedUniverse;
+    }
+
     public IReadOnlyList<IUniverseObject> UniverseObjects => _universeObjects;
 
     public UniverseTime Time { get; private set; } = new();
@@ -34,7 +46,7 @@ public class Universe : BaseEntity, IUniverse
 
             float previousTimeScale = _timeScale;
             _timeScale = value;
-            OnTimeScaleChanged?.InvokeSafe(this, previousTimeScale);
+            OnTimeScaleChanged?.Invoke(this, new(previousTimeScale));
         }
     }
 
@@ -43,8 +55,10 @@ public class Universe : BaseEntity, IUniverse
         if (_universeObjects.Contains(universeObject))
             throw new Exception($"{nameof(IUniverseObject)} named {universeObject.Name} is already registered to the {nameof(Universe)}.");
 
-        universeObject.OnFinalized += OnUniverseObjectFinalize;
-        universeObject.OnExitedUniverse += OnUniverseObjectExitedUniverse;
+        OnPreUniverseObjectRegistered?.Invoke(this, new(universeObject));
+
+        universeObject.OnFinalized.AddListener(delegateOnUniverseObjectFinalize);
+        universeObject.OnExitedUniverse.AddListener(delegateOnUniverseObjectExitedUniverse);
 
         if (!universeObject.Initialize())
             throw new Exception($"{universeObject.Name} can't be initialized");
@@ -57,7 +71,7 @@ public class Universe : BaseEntity, IUniverse
         if (!universeObject.EnterUniverse(this))
             throw new Exception($"{universeObject.Name} can't enter the universe");
 
-        OnUniverseObjectRegistered?.InvokeSafe(this, universeObject);
+        OnUniverseObjectRegistered?.Invoke(this, new(universeObject));
     }
 
     public T InstantiateUniverseObject<T>(params object?[]? args) where T : class, IUniverseObject
@@ -69,7 +83,7 @@ public class Universe : BaseEntity, IUniverse
 
     public void Remove(IUniverseObject universeObject)
     {
-        universeObject.SetParent(null);
+        universeObject.Parent = null;
         RemoveIncursive(universeObject);
     }
 
@@ -78,8 +92,10 @@ public class Universe : BaseEntity, IUniverse
         if (!_universeObjects.Contains(universeObject))
             throw new Exception($"{nameof(IUniverseObject)} named {universeObject.Name} is not registered to the {nameof(Universe)}.");
 
-        universeObject.OnFinalized -= OnUniverseObjectFinalize;
-        universeObject.OnExitedUniverse -= OnUniverseObjectExitedUniverse;
+        OnPreUniverseObjectUnRegistered?.Invoke(this, new(universeObject));
+
+        universeObject.OnFinalized.RemoveListener(delegateOnUniverseObjectFinalize);
+        universeObject.OnExitedUniverse.RemoveListener(delegateOnUniverseObjectExitedUniverse);
 
         for (int i = universeObject.Children.Count - 1; i >= 0; i--)
             Remove(universeObject.Children[i]);
@@ -92,7 +108,7 @@ public class Universe : BaseEntity, IUniverse
         if (!universeObject.Finalize())
             throw new Exception($"{universeObject.Name} can't be finalized");
 
-        OnUniverseObjectUnRegistered?.InvokeSafe(this, universeObject);
+        OnUniverseObjectUnRegistered?.Invoke(this, new(universeObject));
     }
 
     protected override void InitializeInternal()
@@ -115,22 +131,18 @@ public class Universe : BaseEntity, IUniverse
         UnscaledTime = engineTime;
         Time = new(TimeSpan.FromTicks((long)(Time.TimeSinceStart.Ticks + engineTime.DeltaSpan.Ticks * TimeScale)), TimeSpan.FromTicks((long)(engineTime.DeltaSpan.Ticks * TimeScale)));
 
-        OnPreUpdate?.InvokeSafe(this, Time);
-
-        for (int i = 0; i < UniverseObjects.Count; i++)
-            UniverseObjects[i].BehaviourController.Update();
-
-        OnUpdate?.InvokeSafe(this, Time);
+        OnPreUpdate?.Invoke(this, new(Time));
+        OnUpdate?.Invoke(this, new(Time));
+        OnPostUpdate?.Invoke(this, new(Time));
     }
 
-    public void PreDraw()
+    public void Draw()
     {
         Debug.Assert.AssertInitialized(this);
 
-        for (int i = 0; i < UniverseObjects.Count; i++)
-            UniverseObjects[i].BehaviourController.UpdatePreDraw();
-
-        OnPreDraw?.InvokeSafe(this);
+        OnPreDraw?.Invoke(this);
+        OnDraw?.Invoke(this);
+        OnPostDraw?.Invoke(this);
     }
 
     private void OnUniverseObjectFinalize(IInitializable initializable)
@@ -139,7 +151,7 @@ public class Universe : BaseEntity, IUniverse
             Remove(universeObject);
     }
 
-    private void OnUniverseObjectExitedUniverse(IUniverseObject sender, IUniverse universe)
+    private void OnUniverseObjectExitedUniverse(IUniverseObject sender, IUniverseObject.ExitedUniverseArguments args)
     {
         if (sender is IUniverseObject universeObject)
             Remove(universeObject);

Engine.Core/UniverseObject.cs

@@ -1,4 +1,3 @@
-using System.Collections;
 using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
@@ -6,22 +5,23 @@ namespace Syntriax.Engine.Core;
 [System.Diagnostics.DebuggerDisplay("Name: {Name}, Initialized: {Initialized}")]
 public class UniverseObject : BaseEntity, IUniverseObject
 {
-    public event IUniverseObject.EnteredUniverseEventHandler? OnEnteredUniverse = null;
-    public event IUniverseObject.ExitedUniverseEventHandler? OnExitedUniverse = null;
-    public event IUniverseObject.ParentChangedEventHandler? OnParentChanged = null;
-    public event IUniverseObject.ChildrenAddedEventHandler? OnChildrenAdded = null;
-    public event IUniverseObject.ChildrenRemovedEventHandler? OnChildrenRemoved = null;
-    public event IHasBehaviourController.BehaviourControllerAssignedEventHandler? OnBehaviourControllerAssigned = null;
-    public event INameable.NameChangedEventHandler? OnNameChanged = null;
-    public event IActive.ActiveChangedEventHandler? OnActiveChanged = null;
+    public Event<IUniverseObject, IUniverseObject.EnteredUniverseArguments> OnEnteredUniverse { get; } = new();
+    public Event<IUniverseObject, IUniverseObject.ExitedUniverseArguments> OnExitedUniverse { get; } = new();
+    public Event<IUniverseObject, IUniverseObject.ParentChangedArguments> OnParentChanged { get; } = new();
+    public Event<IUniverseObject, IUniverseObject.ChildrenAddedArguments> OnChildrenAdded { get; } = new();
+    public Event<IUniverseObject, IUniverseObject.ChildrenRemovedArguments> OnChildrenRemoved { get; } = new();
+
+    public Event<IActive, IActive.ActiveChangedArguments> OnActiveChanged { get; } = new();
+    public Event<INameable, INameable.NameChangedArguments> OnNameChanged { get; } = new();
+    public Event<IHasBehaviourController> OnBehaviourControllerAssigned { get; } = new();
 
     private string _name = nameof(UniverseObject);
     private IUniverse _universe = null!;
     private IBehaviourController _behaviourController = null!;
     private bool _isActive = false;
     private readonly List<IUniverseObject> _children = [];
+    private IUniverseObject? _parent = null;
 
-    public IUniverseObject? Parent { get; private set; } = null;
     public IReadOnlyList<IUniverseObject> Children => _children;
     public IBehaviourController BehaviourController => _behaviourController;
     public IUniverse Universe => _universe;
@@ -37,7 +37,41 @@ public class UniverseObject : BaseEntity, IUniverseObject
 
             string previousName = _name;
             _name = value;
-            OnNameChanged?.InvokeSafe(this, previousName);
+            OnNameChanged?.Invoke(this, new(previousName));
+        }
+    }
+
+    public IUniverseObject? Parent
+    {
+        get => _parent;
+        set
+        {
+            if (value == this)
+                throw new Exceptions.AssignFailedException($"{Name} can not parent itself");
+
+            if (_parent == value)
+                return;
+
+            IUniverseObject? previousParent = Parent;
+            if (previousParent is not null)
+            {
+                previousParent.RemoveChild(this);
+                previousParent.OnActiveChanged.RemoveListener(OnParentActiveChanged);
+            }
+
+            _parent = value;
+
+            if (value is not null)
+            {
+                if (value.IsInUniverse && !IsInUniverse)
+                    value.Universe.Register(this);
+
+                value.AddChild(this);
+                value.OnActiveChanged.AddListener(OnParentActiveChanged);
+            }
+
+            UpdateActive();
+            OnParentChanged?.Invoke(this, new(previousParent, value));
         }
     }
 
@@ -50,7 +84,7 @@ public class UniverseObject : BaseEntity, IUniverseObject
         _universe = universe;
         UpdateActive();
         OnEnteringUniverse(universe);
-        OnEnteredUniverse?.InvokeSafe(this, universe);
+        OnEnteredUniverse?.Invoke(this, new(universe));
         return true;
     }
 
@@ -62,48 +96,18 @@ public class UniverseObject : BaseEntity, IUniverseObject
 
         OnExitingUniverse(universe);
         _universe = null!;
-        OnExitedUniverse?.InvokeSafe(this, universe);
+        OnExitedUniverse?.Invoke(this, new(universe));
         return true;
     }
 
-    public void SetParent(IUniverseObject? parent)
-    {
-        if (parent == this)
-            throw new Exceptions.AssignFailedException($"{Name} can not parent itself");
-
-        if (Parent == parent)
-            return;
-
-        IUniverseObject? previousParent = Parent;
-        if (previousParent is not null)
-        {
-            previousParent.RemoveChild(this);
-            previousParent.OnActiveChanged -= OnParentActiveChanged;
-        }
-
-        Parent = parent;
-
-        if (parent is not null)
-        {
-            if (parent.IsInUniverse && !IsInUniverse)
-                parent.Universe.Register(this);
-
-            parent.AddChild(this);
-            parent.OnActiveChanged += OnParentActiveChanged;
-        }
-
-        UpdateActive();
-        OnParentChanged?.InvokeSafe(this, previousParent, parent);
-    }
-
     public void AddChild(IUniverseObject parent)
     {
         if (_children.Contains(parent))
             return;
 
         _children.Add(parent);
-        parent.SetParent(this);
-        OnChildrenAdded?.InvokeSafe(this, parent);
+        parent.Parent = this;
+        OnChildrenAdded?.Invoke(this, new(parent));
     }
 
     public void RemoveChild(IUniverseObject child)
@@ -111,8 +115,8 @@ public class UniverseObject : BaseEntity, IUniverseObject
         if (!_children.Remove(child))
             return;
 
-        child.SetParent(null);
-        OnChildrenRemoved?.InvokeSafe(this, child);
+        child.Parent = null;
+        OnChildrenRemoved?.Invoke(this, new(child));
     }
 
     protected virtual void OnAssign(IBehaviourController behaviourController) { }
@@ -123,7 +127,7 @@ public class UniverseObject : BaseEntity, IUniverseObject
 
         _behaviourController = behaviourController;
         OnAssign(behaviourController);
-        OnBehaviourControllerAssigned?.InvokeSafe(this);
+        OnBehaviourControllerAssigned?.Invoke(this);
         return true;
     }
 
@@ -131,11 +135,12 @@ public class UniverseObject : BaseEntity, IUniverseObject
     {
         base.OnAssign(stateEnable);
 
-        stateEnable.OnEnabledChanged += OnStateEnabledChanged;
+        stateEnable.OnEnabledChanged.AddListener(OnStateEnabledChanged);
+        UpdateActive();
     }
 
-    private void OnParentActiveChanged(IActive sender, bool previousState) => UpdateActive();
-    private void OnStateEnabledChanged(IStateEnable sender, bool previousState) => UpdateActive();
+    private void OnParentActiveChanged(IActive sender, IActive.ActiveChangedArguments args) => UpdateActive();
+    private void OnStateEnabledChanged(IStateEnable sender, IStateEnable.EnabledChangedArguments args) => UpdateActive();
 
     private void UpdateActive()
     {
@@ -143,13 +148,13 @@ public class UniverseObject : BaseEntity, IUniverseObject
         _isActive = StateEnable.Enabled && (Parent?.IsActive ?? true);
 
         if (previousActive != IsActive)
-            OnActiveChanged?.InvokeSafe(this, previousActive);
+            OnActiveChanged?.Invoke(this, new(previousActive));
     }
 
     protected override void UnassignInternal()
     {
         base.UnassignInternal();
-        StateEnable.OnEnabledChanged -= OnStateEnabledChanged;
+        StateEnable.OnEnabledChanged.RemoveListener(OnStateEnabledChanged);
     }
 
     protected override void InitializeInternal()
@@ -163,7 +168,4 @@ public class UniverseObject : BaseEntity, IUniverseObject
     {
         _name = GetType().Name;
     }
-
-    public IEnumerator<IUniverseObject> GetEnumerator() => _children.GetEnumerator();
-    IEnumerator IEnumerable.GetEnumerator() => _children.GetEnumerator();
 }

Engine.Integration/Engine.Integration.MonoGame/Abstract/IDrawableSprite.cs

@@ -0,0 +1,8 @@
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public interface IDrawableSprite : IBehaviour
+{
+    void Draw(ISpriteBatch spriteBatch);
+}

Engine.Integration/Engine.Integration.MonoGame/Abstract/IDrawableTriangle.cs

@@ -0,0 +1,8 @@
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public interface IDrawableTriangle : IBehaviour
+{
+    void Draw(ITriangleBatch triangleBatch);
+}

Engine.Integration/Engine.Integration.MonoGame/Abstract/ILoadContent.cs

@@ -0,0 +1,10 @@
+using Microsoft.Xna.Framework.Content;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public interface ILoadContent : IBehaviour
+{
+    void LoadContent(ContentManager content);
+}

Engine.Integration/Engine.Integration.MonoGame/Abstract/ISpriteBatch.cs

@@ -0,0 +1,29 @@
+using System.Text;
+
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public interface ISpriteBatch
+{
+    void Begin(SpriteSortMode sortMode = SpriteSortMode.Deferred, BlendState? blendState = null, SamplerState? samplerState = null, DepthStencilState? depthStencilState = null, RasterizerState? rasterizerState = null, Effect? effect = null, Matrix? transformMatrix = null);
+    void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth);
+    void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth);
+    void Draw(Texture2D texture, AABB destinationAABB, AABB? sourceAABB, Color color, float rotation, Vector2D origin, SpriteEffects effects, float layerDepth);
+    void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color);
+    void Draw(Texture2D texture, AABB destinationAABB, AABB? sourceAABB, Color color);
+    void Draw(Texture2D texture, Vector2D position, Color color);
+    void Draw(Texture2D texture, AABB destinationAABB, Color color);
+    void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color);
+    void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth);
+    void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth);
+    void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth, bool rtl);
+    void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color);
+    void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth);
+    void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth);
+    void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth, bool rtl);
+    void End();
+}

Engine.Integration/Engine.Integration.MonoGame/Abstract/ITriangleBatch.cs

@@ -0,0 +1,12 @@
+using Microsoft.Xna.Framework;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public interface ITriangleBatch
+{
+    void Begin(Matrix? view = null, Matrix? projection = null);
+    void Draw(Triangle triangle, ColorRGBA colorRGBA);
+    void End();
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/DrawableShape.cs

@@ -0,0 +1,29 @@
+using System.Collections.Generic;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class DrawableShape : Behaviour2D, IDrawableTriangle, IPreDraw
+{
+    private readonly Shape2D shape = new([]);
+    private readonly List<Triangle> worldTriangles = [];
+    private readonly Shape2D worldShape = new([]);
+    protected ColorRGB color = new(255, 255, 255);
+
+    public void PreDraw() => UpdateWorldShape();
+
+    public void Draw(ITriangleBatch triangleBatch)
+    {
+        worldShape.ToTrianglesConvex(worldTriangles);
+
+        foreach (Triangle triangle in worldTriangles)
+            triangleBatch.Draw(new(triangle.C, triangle.B, triangle.A), color);
+    }
+
+    protected void UpdateWorldShape() => shape.Transform(Transform, worldShape);
+
+    public DrawableShape() => shape = Shape2D.Triangle;
+    public DrawableShape(Shape2D shape) => this.shape = shape;
+    public DrawableShape(Shape2D shape, ColorRGB color) { this.shape = shape; this.color = color; }
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/KeyboardInputs.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+
+using Microsoft.Xna.Framework.Input;
+
+using Syntriax.Engine.Core;
+using Syntriax.Engine.Systems.Input;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class KeyboardInputs : Behaviour, IButtonInputs<Keys>, IUpdate
+{
+    public Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments> OnAnyButtonPressed { get; } = new();
+    public Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments> OnAnyButtonReleased { get; } = new();
+
+    private readonly Dictionary<Keys, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>> OnPressed = new(256);
+    private readonly Dictionary<Keys, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>> OnReleased = new(256);
+
+    private int cachePressedCurrentlyCount = 0;
+    private readonly Keys[] cachePressedCurrently = new Keys[256];
+
+    private int cachePressedPreviouslyCount = 0;
+    private readonly Keys[] cachePressedPreviously = new Keys[256];
+
+    public void RegisterOnPress(Keys key, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>.EventHandler callback)
+    {
+        if (!OnPressed.TryGetValue(key, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? delegateCallback))
+        {
+            delegateCallback = new();
+            OnPressed.Add(key, delegateCallback);
+        }
+
+        delegateCallback.AddListener(callback);
+    }
+
+    public void UnregisterOnPress(Keys key, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>.EventHandler callback)
+    {
+        if (OnPressed.TryGetValue(key, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? delegateCallback))
+            delegateCallback.RemoveListener(callback);
+    }
+
+    public void RegisterOnRelease(Keys key, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>.EventHandler callback)
+    {
+        if (!OnReleased.TryGetValue(key, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? delegateCallback))
+        {
+            delegateCallback = new();
+            OnReleased.Add(key, delegateCallback);
+        }
+
+        delegateCallback.AddListener(callback);
+    }
+
+    public void UnregisterOnRelease(Keys key, Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>.EventHandler callback)
+    {
+        if (OnReleased.TryGetValue(key, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? delegateCallback))
+            delegateCallback.RemoveListener(callback);
+    }
+
+    public void Update()
+    {
+        KeyboardState keyboardState = Keyboard.GetState();
+        keyboardState.GetPressedKeys(cachePressedCurrently);
+        cachePressedCurrentlyCount = keyboardState.GetPressedKeyCount();
+
+        for (int i = 0; i < cachePressedCurrentlyCount; i++)
+        {
+            Keys currentlyPressedKey = cachePressedCurrently[i];
+
+            if (WasPressed(currentlyPressedKey))
+                continue;
+
+            if (OnPressed.TryGetValue(currentlyPressedKey, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? callback))
+                callback?.Invoke(this, new(currentlyPressedKey));
+
+            OnAnyButtonPressed?.Invoke(this, new(currentlyPressedKey));
+        }
+
+        for (int i = 0; i < cachePressedPreviouslyCount; i++)
+        {
+            Keys previouslyPressedKey = cachePressedPreviously[i];
+
+            if (IsPressed(previouslyPressedKey))
+                continue;
+
+            if (OnReleased.TryGetValue(previouslyPressedKey, out Event<IButtonInputs<Keys>, IButtonInputs<Keys>.ButtonCallbackArguments>? callback))
+                callback?.Invoke(this, new(previouslyPressedKey));
+
+            OnAnyButtonReleased?.Invoke(this, new(previouslyPressedKey));
+        }
+
+        Array.Copy(cachePressedCurrently, cachePressedPreviously, cachePressedCurrentlyCount);
+        cachePressedPreviouslyCount = cachePressedCurrentlyCount;
+    }
+
+    public bool IsPressed(Keys key)
+    {
+        for (int i = 0; i < cachePressedCurrentlyCount; i++)
+            if (cachePressedCurrently[i] == key)
+                return true;
+        return false;
+    }
+
+    private bool WasPressed(Keys key)
+    {
+        for (int i = 0; i < cachePressedPreviouslyCount; i++)
+            if (cachePressedPreviously[i] == key)
+                return true;
+        return false;
+    }
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/LoadContentManager.cs

@@ -0,0 +1,53 @@
+using System.Collections.Generic;
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class LoadContentManager : Behaviour, IFirstFrameUpdate
+{
+    // We use Ascending order because we are using reverse for loop to call them
+    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private readonly ActiveBehaviourCollectorSorted<ILoadContent> loadContents = new() { SortBy = SortByAscendingPriority() };
+    private readonly List<ILoadContent> toCallLoadContents = new(32);
+
+    private MonoGameWindowContainer monoGameWindowContainer = null!;
+
+    public void FirstActiveFrame()
+    {
+        monoGameWindowContainer = Universe.FindRequiredBehaviour<MonoGameWindowContainer>();
+    }
+
+    protected override void OnEnteredUniverse(IUniverse universe)
+    {
+        loadContents.Assign(universe);
+
+        universe.OnPreUpdate.AddListener(OnPreUpdate);
+    }
+
+    protected override void OnExitedUniverse(IUniverse universe)
+    {
+        loadContents.Unassign();
+
+        universe.OnPreUpdate.RemoveListener(OnPreUpdate);
+    }
+
+    private void OnPreUpdate(IUniverse sender, IUniverse.UpdateArguments args)
+    {
+        for (int i = toCallLoadContents.Count - 1; i >= 0; i--)
+        {
+            toCallLoadContents[i].LoadContent(monoGameWindowContainer.Window.Content);
+            toCallLoadContents.RemoveAt(i);
+        }
+    }
+
+    private void OnFirstFrameCollected(IBehaviourCollector<ILoadContent> sender, IBehaviourCollector<ILoadContent>.BehaviourCollectedArguments args)
+    {
+        toCallLoadContents.Add(args.BehaviourCollected);
+    }
+
+    public LoadContentManager()
+    {
+        loadContents.OnCollected.AddListener(OnFirstFrameCollected);
+    }
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/MonoGameCamera2D.cs

@@ -0,0 +1,109 @@
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class MonoGameCamera2D : BehaviourBase, ICamera2D, IFirstFrameUpdate, IPreDraw
+{
+    public event MatrixTransformChangedArguments? OnMatrixTransformChanged = null;
+    public event ViewportChangedArguments? OnViewportChanged = null;
+    public event ZoomChangedArguments? OnZoomChanged = null;
+
+    private Matrix _matrixTransform = Matrix.Identity;
+
+    private Viewport _viewport = default;
+    private float _zoom = 1f;
+
+    public GraphicsDeviceManager Graphics { get; private set; } = null!;
+    public ITransform2D Transform { get; private set; } = null!;
+
+    public Matrix MatrixTransform
+    {
+        get => _matrixTransform;
+        set
+        {
+            if (_matrixTransform == value)
+                return;
+
+            _matrixTransform = value;
+            OnMatrixTransformChanged?.Invoke(this);
+        }
+    }
+
+    public Vector2D Position
+    {
+        get => Transform.Position;
+        set => Transform.Position = value;
+    }
+
+    public Viewport Viewport
+    {
+        get => _viewport;
+        set
+        {
+            if (_viewport.Equals(value))
+                return;
+
+            _viewport = value;
+            OnViewportChanged?.Invoke(this);
+        }
+    }
+
+    public float Zoom
+    {
+        get => _zoom;
+        set
+        {
+            float newValue = Syntriax.Engine.Core.Math.Max(0.1f, value);
+
+            if (_zoom == newValue)
+                return;
+
+            _zoom = newValue;
+            OnZoomChanged?.Invoke(this);
+        }
+    }
+
+    public float Rotation
+    {
+        get => Transform.Rotation;
+        set => Transform.Rotation = value;
+    }
+
+    // TODO This causes delay since OnPreDraw calls assuming this is called in in Update 
+    public Vector2D ScreenToWorldPosition(Vector2D screenPosition)
+    {
+        Vector2D worldPosition = Vector2.Transform(screenPosition.ToVector2(), Matrix.Invert(MatrixTransform)).ToVector2D();
+        return worldPosition.Scale(EngineConverterExtensions.screenScale);
+    }
+    public Vector2D WorldToScreenPosition(Vector2D worldPosition)
+    {
+        Vector2D screenPosition = Vector2.Transform(worldPosition.ToVector2(), MatrixTransform).ToVector2D();
+        return screenPosition.Scale(EngineConverterExtensions.screenScale);
+    }
+
+    public void FirstActiveFrame()
+    {
+        Graphics = BehaviourController.UniverseObject.Universe.FindRequiredBehaviour<MonoGameWindowContainer>().Window.Graphics;
+        Viewport = Graphics.GraphicsDevice.Viewport;
+    }
+
+    public void PreDraw()
+    {
+        MatrixTransform =
+            Matrix.CreateTranslation(new Vector3(-Position.X, Position.Y, 0f)) *
+            Matrix.CreateRotationZ(Rotation * Syntriax.Engine.Core.Math.DegreeToRadian) *
+            Matrix.CreateScale(Transform.Scale.X.Max(Transform.Scale.Y)) *
+            Matrix.CreateScale(Zoom) *
+            Matrix.CreateTranslation(new Vector3(_viewport.Width * .5f, _viewport.Height * .5f, 0f));
+    }
+
+    protected sealed override void InitializeInternal() => Transform = BehaviourController.GetRequiredBehaviour<ITransform2D>();
+    protected sealed override void FinalizeInternal() => Transform = null!;
+
+    public delegate void MatrixTransformChangedArguments(MonoGameCamera2D sender);
+    public delegate void ViewportChangedArguments(MonoGameCamera2D sender);
+    public delegate void ZoomChangedArguments(MonoGameCamera2D sender);
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/SpriteBatchWrapper.cs

@@ -0,0 +1,64 @@
+using System.Text;
+
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class SpriteBatchWrapper(GraphicsDevice graphicsDevice) : ISpriteBatch
+{
+    private readonly SpriteBatch spriteBatch = new(graphicsDevice);
+
+    public void Begin(SpriteSortMode sortMode = SpriteSortMode.Deferred, BlendState? blendState = null, SamplerState? samplerState = null, DepthStencilState? depthStencilState = null, RasterizerState? rasterizerState = null, Effect? effect = null, Matrix? transformMatrix = null)
+        => spriteBatch.Begin(sortMode, blendState, samplerState, depthStencilState, rasterizerState, effect, transformMatrix);
+
+    public void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.Draw(texture, position.ToDisplayVector2(), sourceAABB?.ToRectangle(), color, rotation, origin.ToDisplayVector2(), scale.ToDisplayVector2(), effects, layerDepth);
+
+    public void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.Draw(texture, position.ToDisplayVector2(), sourceAABB?.ToRectangle(), color, rotation, origin.ToDisplayVector2(), scale, effects, layerDepth);
+
+    public void Draw(Texture2D texture, AABB destinationAABB, AABB? sourceAABB, Color color, float rotation, Vector2D origin, SpriteEffects effects, float layerDepth)
+        => spriteBatch.Draw(texture, destinationAABB.ToRectangle(), sourceAABB?.ToRectangle(), color, rotation, origin.ToDisplayVector2(), effects, layerDepth);
+
+    public void Draw(Texture2D texture, Vector2D position, AABB? sourceAABB, Color color)
+        => spriteBatch.Draw(texture, position.ToDisplayVector2(), sourceAABB?.ToRectangle(), color);
+
+    public void Draw(Texture2D texture, AABB destinationAABB, AABB? sourceAABB, Color color)
+        => spriteBatch.Draw(texture, destinationAABB.ToRectangle(), sourceAABB?.ToRectangle(), color);
+
+    public void Draw(Texture2D texture, Vector2D position, Color color)
+        => spriteBatch.Draw(texture, position.ToDisplayVector2(), color);
+
+    public void Draw(Texture2D texture, AABB destinationAABB, Color color)
+        => spriteBatch.Draw(texture, destinationAABB.ToRectangle(), color);
+
+    public void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color);
+
+    public void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale, effects, layerDepth);
+
+    public void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale.ToDisplayVector2(), effects, layerDepth);
+
+    public void DrawString(SpriteFont spriteFont, string text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth, bool rtl)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale.ToDisplayVector2(), effects, layerDepth, rtl);
+
+    public void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color);
+
+    public void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, float scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale, effects, layerDepth);
+
+    public void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale.ToDisplayVector2(), effects, layerDepth);
+
+    public void DrawString(SpriteFont spriteFont, StringBuilder text, Vector2D position, Color color, float rotation, Vector2D origin, Vector2D scale, SpriteEffects effects, float layerDepth, bool rtl)
+        => spriteBatch.DrawString(spriteFont, text, position.ToDisplayVector2(), color, rotation, origin.ToDisplayVector2(), scale.ToDisplayVector2(), effects, layerDepth, rtl);
+
+    public void End()
+        => spriteBatch.End();
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/SpriteBatcher.cs

@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class SpriteBatcher : BehaviourBase, IFirstFrameUpdate, IDraw
+{
+    private static Comparer<IBehaviour> SortByPriority() => Comparer<IBehaviour>.Create((x, y) => y.Priority.CompareTo(x.Priority));
+
+    private ISpriteBatch spriteBatch = null!;
+    private MonoGameCamera2D camera2D = null!;
+
+    private readonly ActiveBehaviourCollectorSorted<IDrawableSprite> drawableSprites = new() { SortBy = SortByPriority() };
+
+    public void FirstActiveFrame()
+    {
+        MonoGameWindowContainer windowContainer = Universe.FindRequiredBehaviour<MonoGameWindowContainer>();
+        camera2D = Universe.FindRequiredBehaviour<MonoGameCamera2D>();
+
+        spriteBatch = new SpriteBatchWrapper(windowContainer.Window.GraphicsDevice);
+        drawableSprites.Unassign();
+        drawableSprites.Assign(Universe);
+    }
+
+    public void Draw()
+    {
+        spriteBatch.Begin(transformMatrix: camera2D.MatrixTransform);
+        for (int i = 0; i < drawableSprites.Count; i++)
+            drawableSprites[i].Draw(spriteBatch);
+        spriteBatch.End();
+    }
+}

Engine.Integration/Engine.Integration.MonoGame/Behaviours/TriangleBatcher.cs

@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+
+using Microsoft.Xna.Framework;
+
+using Syntriax.Engine.Core;
+
+namespace Syntriax.Engine.Integration.MonoGame;
+
+public class TriangleBatcher : BehaviourBase, ITriangleBatch, IFirstFrameUpdate, IDraw
+{
+    private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));
+
+    private TriangleBatch triangleBatch = null!;
+    private MonoGameCamera2D camera2D = null!;
+    private readonly ActiveBehaviourCollectorSorted<IDrawableTriangle> drawableShapes = new() { SortBy = SortByAscendingPriority() };
+
+    public void FirstActiveFrame()
+    {
+        MonoGameWindowContainer windowContainer = BehaviourController.UniverseObject.Universe.FindRequiredBehaviour<MonoGameWindowContainer>();
+        camera2D = BehaviourController.UniverseObject.Universe.FindRequiredBehaviour<MonoGameCamera2D>();
+
+        triangleBatch = new(windowContainer.Window.GraphicsDevice);
+        drawableShapes.Unassign();
+        drawableShapes.Assign(BehaviourController.UniverseObject.Universe);
+    }
+
+    public void Draw()
+    {
+        triangleBatch.Begin(camera2D.MatrixTransform);
+        for (int i = 0; i < drawableShapes.Count; i++)
+            drawableShapes[i].Draw(triangleBatch);
+        triangleBatch.End();
+    }
+
+    public void Begin(Matrix? view = null, Matrix? projection = null) => triangleBatch.Begin(view, projection);
+    public void Draw(Triangle triangle, ColorRGBA colorRGBA) => triangleBatch.Draw(triangle, colorRGBA);
+    public void End() => triangleBatch.End();
+}

Engine.Integration/Engine.Integration.MonoGame/Engine.Integration.MonoGame.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>disable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <RootNamespace>Syntriax.Engine.Integration.MonoGame</RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="MonoGame.Framework.DesktopGL" Version="3.8.2.1105">
+      <PrivateAssets>All</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\Engine\Engine.csproj" />
+  </ItemGroup>
+</Project>