feat!: GetRequiredBehaviour/HierarchyObject methods added for cleaner null handling

Engine.Core/GameManager.cs

@@ -3,7 +3,7 @@ using System.Collections;
 using System.Collections.Generic;
 
 using Syntriax.Engine.Core.Abstract;
-using Syntriax.Engine.Core.Exceptions;
+using Syntriax.Engine.Core.Helpers;
 
 namespace Syntriax.Engine.Core;
 
@@ -22,21 +22,6 @@ public class GameManager : BaseEntity, IGameManager
 
     public IReadOnlyList<IHierarchyObject> HierarchyObjects => _hierarchyObjects;
 
-    public override IStateEnable StateEnable
-    {
-        get
-        {
-            if (base.StateEnable is null)
-            {
-                Assign(Factory.StateEnableFactory.Instantiate(this));
-                if (base.StateEnable is null)
-                    throw NotAssignedException.From(this, base.StateEnable);
-            }
-
-            return base.StateEnable;
-        }
-    }
-
     public EngineTime Time { get; private set; } = new();
     public EngineTime UnscaledTime { get; private set; } = new();
     public float TimeScale
@@ -104,9 +89,6 @@ public class GameManager : BaseEntity, IGameManager
 
     protected override void InitializeInternal()
     {
-        base.InitializeInternal();
-        NotAssignedException.Check(this, StateEnable);
-
         foreach (IHierarchyObject hierarchyObject in HierarchyObjects)
             hierarchyObject.Initialize();
     }
@@ -120,6 +102,8 @@ public class GameManager : BaseEntity, IGameManager
 
     public void Update(EngineTime engineTime)
     {
+        AssertHelpers.AssertInitialized(this);
+
         UnscaledTime = engineTime;
         Time = new(TimeSpan.FromTicks((long)(Time.TimeSinceStart.Ticks + engineTime.DeltaSpan.Ticks * TimeScale)), TimeSpan.FromTicks((long)(engineTime.DeltaSpan.Ticks * TimeScale)));
 
@@ -133,6 +117,8 @@ public class GameManager : BaseEntity, IGameManager
 
     public void PreDraw()
     {
+        AssertHelpers.AssertInitialized(this);
+
         for (int i = 0; i < HierarchyObjects.Count; i++)
             HierarchyObjects[i].BehaviourController.UpdatePreDraw();