slight entity manager optimization

encompass-cs/Engine.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Reflection;
 using System.Collections.Generic;
 using System.Linq;
@@ -151,17 +151,6 @@ namespace Encompass
             return entityManager.EntityExists(entity.ID);
         }
 
-        /// <summary>
-        /// Returns the Entity with the specified ID.
-        /// </summary>
-        /// <exception cref="Encompass.Exceptions.EntityNotFoundException">
-        /// Thrown when an Entity with the given ID does not exist.
-        /// </exception>
-        internal Entity GetEntity(Guid entityID)
-        {
-            return entityManager.GetEntity(entityID);
-        }
-
         /// <summary>
         /// Returns an Entity containing the specified Component type.
         /// </summary>

encompass-cs/EntityManager.cs

@@ -1,4 +1,4 @@
-using System.Linq;
+using System.Linq;
 using System;
 using System.Collections.Generic;
 using Encompass.Exceptions;
@@ -7,7 +7,7 @@ namespace Encompass
 {
     internal class EntityManager
     {
-        private readonly Dictionary<Guid, Entity> IDToEntity = new Dictionary<Guid, Entity>(1024);
+        private readonly HashSet<Guid> IDs = new HashSet<Guid>();
 
         private readonly HashSet<Entity> entitiesMarkedForDestroy = new HashSet<Entity>();
 
@@ -22,25 +22,13 @@ namespace Encompass
         {
             var id = NextID();
             var entity = new Entity(id);
-            IDToEntity[id] = entity;
+            IDs.Add(id);
             return entity;
         }
 
         public bool EntityExists(Guid id)
         {
-            return IDToEntity.ContainsKey(id);
-        }
-
-        public Entity GetEntity(Guid id)
-        {
-            if (IDToEntity.ContainsKey(id))
-            {
-                return IDToEntity[id];
-            }
-            else
-            {
-                throw new EntityNotFoundException("Entity with ID {0} does not exist.", id);
-            }
+            return IDs.Contains(id);
         }
 
         public void MarkForDestroy(Entity entity)
@@ -53,7 +41,7 @@ namespace Encompass
             foreach (var entity in entitiesMarkedForDestroy)
             {
                 componentManager.MarkAllComponentsOnEntityForRemoval(entity);
-                IDToEntity.Remove(entity.ID);
+                IDs.Remove(entity.ID);
             }
 
             entitiesMarkedForDestroy.Clear();

encompass-cs/Renderer.cs

@@ -19,11 +19,6 @@ namespace Encompass
             this.componentManager = componentManager;
         }
 
-        internal Entity GetEntity(Guid entityID)
-        {
-            return entityManager.GetEntity(entityID);
-        }
-
         protected IEnumerable<Entity> ReadEntities<TComponent>() where TComponent : struct, IComponent
         {
             return ReadComponentsIncludingEntity<TComponent>().Select(tuple => tuple.Item2);