1 files changed, 90 insertions, 0 deletions
diff --git a/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentManager.cs b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentManager.cs
new file mode 100644
index 0000000..a59c87c
--- /dev/null
+++ b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentManager.cs
@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using Microsoft.Xna.Framework;
+using MonoGame.Extended.Collections;
+using MonoGame.Extended.Entities.Systems;
+
+namespace MonoGame.Extended.Entities
+{
+    public interface IComponentMapperService
+    {
+        ComponentMapper<T> GetMapper<T>() where T : class;
+    }
+
+    public class ComponentManager : UpdateSystem, IComponentMapperService
+    {
+        public ComponentManager()
+        {
+            _componentMappers = new Bag<ComponentMapper>();
+            _componentTypes = new Dictionary<Type, int>();
+        }
+
+        private readonly Bag<ComponentMapper> _componentMappers;
+        private readonly Dictionary<Type, int> _componentTypes;
+
+        public Action<int> ComponentsChanged;
+
+        private ComponentMapper<T> CreateMapperForType<T>(int componentTypeId)
+            where T : class
+        {
+            // TODO: We can probably do better than this without a huge performance penalty by creating our own bit vector that grows after the first 32 bits.
+            if (componentTypeId >= 32)
+                throw new InvalidOperationException("Component type limit exceeded. We currently only allow 32 component types for performance reasons.");
+
+            var mapper = new ComponentMapper<T>(componentTypeId, ComponentsChanged);
+            _componentMappers[componentTypeId] = mapper;
+            return mapper;
+        }
+
+        public ComponentMapper GetMapper(int componentTypeId)
+        {
+            return _componentMappers[componentTypeId];
+        }
+
+        public ComponentMapper<T> GetMapper<T>()
+            where T : class
+        {
+            var componentTypeId = GetComponentTypeId(typeof(T));
+
+            if (_componentMappers[componentTypeId] != null)
+                return _componentMappers[componentTypeId] as ComponentMapper<T>;
+
+            return CreateMapperForType<T>(componentTypeId);
+        }
+
+        public int GetComponentTypeId(Type type)
+        {
+            if (_componentTypes.TryGetValue(type, out var id))
+                return id;
+
+            id = _componentTypes.Count;
+            _componentTypes.Add(type, id);
+            return id;
+        }
+
+        public BitVector32 CreateComponentBits(int entityId)
+        {
+            var componentBits = new BitVector32();
+            var mask = BitVector32.CreateMask();
+
+            for (var componentId = 0; componentId < _componentMappers.Count; componentId++)
+            {
+                componentBits[mask] = _componentMappers[componentId]?.Has(entityId) ?? false;
+                mask = BitVector32.CreateMask(mask);
+            }
+
+            return componentBits;
+        }
+
+        public void Destroy(int entityId)
+        {
+            foreach (var componentMapper in _componentMappers)
+                componentMapper?.Delete(entityId);
+        }
+
+        public override void Update(GameTime gameTime)
+        {
+        }
+    }
+}