Changed project name

Ghost.Entities/Component.cs

@@ -0,0 +1,96 @@
+using Ghost.Core;
+using Misaki.HighPerformance.LowLevel.Collections;
+using Misaki.HighPerformance.LowLevel.Utilities;
+
+namespace Ghost.Entities;
+
+public interface IComponent : IIdentifierType
+{
+}
+
+public struct ComponentInfo
+{
+    // public FixedText64 stableName; // Do we actually need this?
+    public int size;
+    public int alignment;
+    public Identifier<IComponent> id;
+}
+
+public static unsafe class ComponentTypeID<T>
+    where T : unmanaged, IComponent
+{
+    public static readonly Identifier<IComponent> value = ComponentRegister.GetOrRegisterComponent<T>();
+}
+
+internal static class ComponentRegister
+{
+    private static int s_nextComponentTypeID = 0;
+    private static Dictionary<IntPtr, Identifier<IComponent>> s_typeHandleToID = new();
+
+    private static List<ComponentInfo> s_registeredComponents = new();
+    private static Dictionary<string, Identifier<IComponent>> s_nameToRuntimeID = new();
+
+    public unsafe static Identifier<IComponent> GetOrRegisterComponent<T>()
+        where T : unmanaged, IComponent
+    {
+        var typeHandle = typeof(T).TypeHandle.Value;
+
+        lock (s_registeredComponents)
+        {
+            if (s_typeHandleToID.TryGetValue(typeHandle, out var existingID))
+            {
+                return existingID;
+            }
+
+            var newID = new Identifier<IComponent>(s_nextComponentTypeID);
+            s_nextComponentTypeID++;
+
+            var stableName = typeof(T).FullName ?? typeof(T).Name;
+
+            var info = new ComponentInfo
+            {
+                // stableName = new FixedText64(stableName),
+                size = sizeof(T),
+                alignment = (int)MemoryUtility.AlignOf<T>(),
+                id = newID,
+            };
+
+            while (s_registeredComponents.Count <= newID.value) s_registeredComponents.Add(default);
+            s_registeredComponents[newID.value] = info;
+
+            s_typeHandleToID[typeHandle] = newID;
+            s_nameToRuntimeID[stableName] = newID;
+
+            return newID;
+        }
+    }
+
+    public static ComponentInfo GetComponentInfo(Identifier<IComponent> typeId)
+    {
+        return s_registeredComponents[typeId];
+    }
+
+    public static int GetHashCode(ReadOnlySpan<Identifier<IComponent>> componentTypeIDs)
+    {
+        var largestID = 0;
+        foreach (var id in componentTypeIDs)
+        {
+            if (id.value > largestID)
+            {
+                largestID = id.value;
+            }
+        }
+
+        var length = UnsafeBitSet.RequiredLength(largestID + 1);
+        var bits = (Span<uint>)stackalloc uint[length];
+        bits.Clear();
+
+        var bitSet = new SpanBitSet(bits);
+        foreach (var id in componentTypeIDs)
+        {
+            bitSet.SetBit(id.value);
+        }
+
+        return bitSet.GetHashCode();
+    }
+}