Added block placement in sim and ECS object tracking

ECS objects are stored in a newly created weak dictionary so that events can be called on them and possibly other things can be done with them

TechbloxModdingAPI/Block.cs

@@ -45,10 +45,12 @@ namespace TechbloxModdingAPI
 		/// <param name="position">The block's position - default block size is 0.2</param>
 		/// <param name="autoWire">Whether the block should be auto-wired (if functional)</param>
 		/// <param name="player">The player who placed the block</param>
+		/// <param name="force"></param>
 		/// <returns>The placed block or null if failed</returns>
-		public static Block PlaceNew(BlockIDs block, float3 position, bool autoWire = false, Player player = null)
+		public static Block PlaceNew(BlockIDs block, float3 position, bool autoWire = false, Player player = null,
+			bool force = false)
 		{
-			if (PlacementEngine.IsInGame && GameState.IsBuildMode())
+			if (PlacementEngine.IsInGame && (GameState.IsBuildMode() || force))
 			{
 				var initializer = PlacementEngine.PlaceBlock(block, position, player, autoWire);
 				var egid = initializer.EGID;
@@ -140,9 +142,10 @@ namespace TechbloxModdingAPI
 		/// <param name="position">The block's position (a block is 0.2 wide in terms of position)</param>
 		/// <param name="autoWire">Whether the block should be auto-wired (if functional)</param>
 		/// <param name="player">The player who placed the block</param>
-		public Block(BlockIDs type, float3 position, bool autoWire = false, Player player = null)
+		/// <param name="force">Place even if not in build mode</param>
+		public Block(BlockIDs type, float3 position, bool autoWire = false, Player player = null, bool force = false)
 		{
-			if (!PlacementEngine.IsInGame || !GameState.IsBuildMode())
+			if (!PlacementEngine.IsInGame || !GameState.IsBuildMode() && !force)
 				throw new BlockException("Blocks can only be placed in build mode.");
 			var initializer = PlacementEngine.PlaceBlock(type, position, player, autoWire);
 			Id = initializer.EGID;

TechbloxModdingAPI/EcsObjectBase.cs

@@ -1,9 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.Linq.Expressions;
 using Svelto.DataStructures;
 using Svelto.ECS;
 using Svelto.ECS.Internal;
-using TechbloxModdingAPI.Blocks;
+using TechbloxModdingAPI.Utility;
 
 namespace TechbloxModdingAPI
 {
@@ -11,6 +12,32 @@ namespace TechbloxModdingAPI
     {
         public abstract EGID Id { get; } //Abstract to support the 'place' Block constructor
 
+        private static readonly Dictionary<Type, WeakDictionary<EGID, EcsObjectBase>> _instances =
+            new Dictionary<Type, WeakDictionary<EGID, EcsObjectBase>>();
+
+        private static readonly WeakDictionary<EGID, EcsObjectBase> _noInstance =
+            new WeakDictionary<EGID, EcsObjectBase>();
+
+        internal static WeakDictionary<EGID, EcsObjectBase> GetInstances(Type type)
+        {
+            return _instances.TryGetValue(type, out var dict) ? dict : null;
+        }
+
+        protected EcsObjectBase()
+        {
+            if (!_instances.TryGetValue(GetType(), out var dict))
+            {
+                dict = new WeakDictionary<EGID, EcsObjectBase>();
+                _instances.Add(GetType(), dict);
+            }
+
+            // ReSharper disable once VirtualMemberCallInConstructor
+            // The ID should not depend on the constructor
+            dict.Add(Id, this);
+        }
+
+        #region ECS initializer stuff
+
         protected internal EcsInitData InitData;
 
         /// <summary>
@@ -22,7 +49,7 @@ namespace TechbloxModdingAPI
             private EntityReference reference;
 
             public static implicit operator EcsInitData(EntityInitializer initializer) => new EcsInitData
-                {group = GetInitGroup(initializer), reference = initializer.reference};
+                { group = GetInitGroup(initializer), reference = initializer.reference };
 
             public EntityInitializer Initializer(EGID id) => new EntityInitializer(id, group, reference);
             public bool Valid => group != null;
@@ -56,8 +83,10 @@ namespace TechbloxModdingAPI
                 returnExpr = Expression.ConvertChecked(memberExpr, invokeMethod.ReturnType);
 
             var lambda =
-                Expression.Lambda<TDelegate>(returnExpr, $"Access{paramType.Name}_{memberName}", new[] {objParam});
+                Expression.Lambda<TDelegate>(returnExpr, $"Access{paramType.Name}_{memberName}", new[] { objParam });
             return lambda.Compile();
         }
+
+        #endregion
     }
 }

TechbloxModdingAPI/Tests/TechbloxModdingAPIPluginTest.cs

@@ -91,7 +91,7 @@ namespace TechbloxModdingAPI.Tests
 							  .Description("Place a block of aluminium at the given coordinates")
 							  .Action((float x, float y, float z) =>
 							  {
-								  var block = Block.PlaceNew(BlockIDs.Cube, new float3(x, y, z));
+								  var block = Block.PlaceNew(BlockIDs.Cube, new float3(x, y, z), force: true);
 								  Logging.CommandLog("Block placed with type: " + block.Type);
 							  })
 							  .Build();

TechbloxModdingAPI/Utility/WeakDictionary.cs

@@ -0,0 +1,138 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace TechbloxModdingAPI.Utility
+{
+    public class WeakDictionary<TKey, TValue> : IDictionary<TKey, TValue> where TValue : class
+    {
+        private Dictionary<TKey, WeakReference<TValue>> _dictionary = new Dictionary<TKey, WeakReference<TValue>>();
+
+        public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
+        {
+            using var enumerator = _dictionary.GetEnumerator();
+            while (enumerator.MoveNext())
+            {
+                if (enumerator.Current.Value.TryGetTarget(out var value))
+                    yield return new KeyValuePair<TKey, TValue>(enumerator.Current.Key, value);
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+
+        public void Add(KeyValuePair<TKey, TValue> item)
+        {
+            Add(item.Key, item.Value);
+        }
+
+        public void Clear()
+        {
+            _dictionary.Clear();
+        }
+
+        public bool Contains(KeyValuePair<TKey, TValue> item)
+        {
+            return TryGetValue(item.Key, out var value) && item.Value == value;
+        }
+
+        public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
+        {
+            throw new System.NotImplementedException();
+        }
+
+        public bool Remove(KeyValuePair<TKey, TValue> item)
+        {
+            return Contains(item) && Remove(item.Key);
+        }
+
+        public int Count => _dictionary.Count;
+        public bool IsReadOnly => false;
+
+        public bool ContainsKey(TKey key)
+        {
+            return _dictionary.ContainsKey(key);
+        }
+
+        public void Add(TKey key, TValue value)
+        {
+            _dictionary.Add(key, new WeakReference<TValue>(value));
+        }
+
+        public bool Remove(TKey key)
+        {
+            return _dictionary.Remove(key);
+        }
+
+        public bool TryGetValue(TKey key, out TValue value)
+        {
+            value = null;
+            return _dictionary.TryGetValue(key, out var reference) && reference.TryGetTarget(out value);
+        }
+
+        public TValue this[TKey key]
+        {
+            get => TryGetValue(key, out var value)
+                ? value
+                : throw new KeyNotFoundException($"Key {key} not found in WeakDictionary.");
+            set => _dictionary[key] = new WeakReference<TValue>(value);
+        }
+
+        public ICollection<TKey> Keys => _dictionary.Keys;
+        public ICollection<TValue> Values => new ValueCollection(this);
+
+        public class ValueCollection : ICollection<TValue>, IReadOnlyCollection<TValue>
+        {
+            private WeakDictionary<TKey, TValue> _dictionary;
+            internal ValueCollection(WeakDictionary<TKey, TValue> dictionary)
+            {
+                _dictionary = dictionary;
+            }
+
+            public IEnumerator<TValue> GetEnumerator()
+            {
+                using var enumerator = _dictionary.GetEnumerator();
+                while (enumerator.MoveNext())
+                {
+                    yield return enumerator.Current.Value;
+                }
+            }
+
+            IEnumerator IEnumerable.GetEnumerator()
+            {
+                return GetEnumerator();
+            }
+
+            public void Add(TValue item)
+            {
+                throw new NotSupportedException("The value collection is read only.");
+            }
+
+            public void Clear()
+            {
+                throw new NotSupportedException("The value collection is read only.");
+            }
+
+            public bool Contains(TValue item)
+            {
+                return _dictionary.Any(kv => kv.Value == item);
+            }
+
+            public void CopyTo(TValue[] array, int arrayIndex)
+            {
+                throw new NotImplementedException();
+            }
+
+            public bool Remove(TValue item)
+            {
+                throw new NotSupportedException("The value collection is read only.");
+            }
+
+            public int Count => _dictionary.Count;
+            public bool IsReadOnly => true;
+        }
+    }
+}