feat: last active frame interface

Engine.Core/Abstract/IUniverse.cs

@@ -37,11 +37,21 @@ public interface IUniverse : IEntity, IEnumerable<IUniverseObject>
     /// </summary>
     Event<IUniverse> OnPostDraw { get; }
 
+    /// <summary>
+    /// Event triggered when a <see cref="IUniverseObject"/> is about to be registered to the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse, UniverseObjectRegisteredArguments> OnPreUniverseObjectRegistered { get; }
+
     /// <summary>
     /// Event triggered when a <see cref="IUniverseObject"/> is registered to the <see cref="IUniverse"/>.
     /// </summary>
     Event<IUniverse, UniverseObjectRegisteredArguments> OnUniverseObjectRegistered { get; }
 
+    /// <summary>
+    /// Event triggered when a <see cref="IUniverseObject"/> is about to be unregistered from the <see cref="IUniverse"/>.
+    /// </summary>
+    Event<IUniverse, UniverseObjectUnRegisteredArguments> OnPreUniverseObjectUnRegistered { get; }
+
     /// <summary>
     /// Event triggered when a <see cref="IUniverseObject"/> is unregistered from the <see cref="IUniverse"/>.
     /// </summary>

Engine.Core/BehaviourCollector.cs

@@ -76,7 +76,7 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
             OnUniverseObjectRegistered(universe, new(universeObject));
 
         universe.OnUniverseObjectRegistered.AddListener(delegateOnUniverseObjectRegistered);
-        universe.OnUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
+        universe.OnPreUniverseObjectUnRegistered.AddListener(delegateOnUniverseObjectUnregistered);
 
         Universe = universe;
         OnAssign(universe);
@@ -94,7 +94,7 @@ public class BehaviourCollector<T> : IBehaviourCollector<T> where T : class
             OnUniverseObjectUnregistered(Universe, new(universeObject));
 
         Universe.OnUniverseObjectRegistered.RemoveListener(delegateOnUniverseObjectRegistered);
-        Universe.OnUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
+        Universe.OnPreUniverseObjectUnRegistered.RemoveListener(delegateOnUniverseObjectUnregistered);
 
         Universe = null!;
         OnUnassigned?.Invoke(this);

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/ILastFrameUpdate.cs

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

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

@@ -8,6 +8,7 @@ public class UpdateManager : Behaviour
     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() };
@@ -17,6 +18,7 @@ public class UpdateManager : Behaviour
     protected override void OnEnteredUniverse(IUniverse universe)
     {
         firstFrameUpdates.Assign(universe);
+        lastFrameUpdates.Assign(universe);
         preUpdateEntities.Assign(universe);
         updateEntities.Assign(universe);
         postUpdateEntities.Assign(universe);
@@ -29,6 +31,7 @@ public class UpdateManager : Behaviour
     protected override void OnExitedUniverse(IUniverse universe)
     {
         firstFrameUpdates.Unassign();
+        lastFrameUpdates.Unassign();
         preUpdateEntities.Unassign();
         updateEntities.Unassign();
         postUpdateEntities.Unassign();
@@ -67,8 +70,14 @@ public class UpdateManager : Behaviour
         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/Universe.cs

@@ -13,7 +13,9 @@ public class Universe : BaseEntity, IUniverse
     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();
 
@@ -53,6 +55,8 @@ public class Universe : BaseEntity, IUniverse
         if (_universeObjects.Contains(universeObject))
             throw new Exception($"{nameof(IUniverseObject)} named {universeObject.Name} is already registered to the {nameof(Universe)}.");
 
+        OnPreUniverseObjectRegistered?.Invoke(this, new(universeObject));
+
         universeObject.OnFinalized.AddListener(delegateOnUniverseObjectFinalize);
         universeObject.OnExitedUniverse.AddListener(delegateOnUniverseObjectExitedUniverse);
 
@@ -88,6 +92,8 @@ public class Universe : BaseEntity, IUniverse
         if (!_universeObjects.Contains(universeObject))
             throw new Exception($"{nameof(IUniverseObject)} named {universeObject.Name} is not registered to the {nameof(Universe)}.");
 
+        OnPreUniverseObjectUnRegistered?.Invoke(this, new(universeObject));
+
         universeObject.OnFinalized.RemoveListener(delegateOnUniverseObjectFinalize);
         universeObject.OnExitedUniverse.RemoveListener(delegateOnUniverseObjectExitedUniverse);