Update EntityManager and Archetype

Ghost.ArcEntities/Entity.cs

@@ -4,26 +4,26 @@ using System.Runtime.InteropServices;
 namespace Ghost.ArcEntities;
 
 [StructLayout(LayoutKind.Sequential, Size = 8)]
-public struct Entity : IEquatable<Entity>, IComparable<Entity>
+public readonly struct Entity : IEquatable<Entity>, IComparable<Entity>
 {
     public const EntityID INVALID_ID = -1;
 
-    private EntityID _id;
-    private GenerationID _generation;
+    private readonly EntityID _id;
+    private readonly GenerationID _generation;
 
-    public readonly EntityID ID
+    public EntityID ID
     {
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get => _id;
     }
 
-    public readonly GenerationID Generation
+    public GenerationID Generation
     {
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get => _generation;
     }
 
-    public readonly bool IsValid
+    public bool IsValid
     {
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get => ID != INVALID_ID;
@@ -41,27 +41,24 @@ public struct Entity : IEquatable<Entity>, IComparable<Entity>
         _generation = generation;
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    internal void IncrementGeneration() => _generation++;
-
-    public readonly bool Equals(Entity other)
+    public bool Equals(Entity other)
     {
         return _id == other._id && _generation == other._generation;
     }
 
-    public readonly int CompareTo(Entity other)
+    public int CompareTo(Entity other)
     {
         return _id.CompareTo(other._id);
     }
 
-    public override readonly bool Equals(object? obj)
+    public override bool Equals(object? obj)
     {
         return obj is Entity other && Equals(other);
     }
 
-    public override readonly int GetHashCode()
+    public override int GetHashCode()
     {
-        return _id.GetHashCode();
+        return _id ^ _generation << 16;
     }
 
     public static bool operator ==(Entity left, Entity right)
@@ -74,7 +71,7 @@ public struct Entity : IEquatable<Entity>, IComparable<Entity>
         return !(left == right);
     }
 
-    public override readonly string ToString()
+    public override string ToString()
     {
         return $"Entity {{ Index: {ID}, Generation: {Generation} }}";
     }