update

src/Builtin/BaseProcesses.cs

@@ -7,24 +7,28 @@ namespace DCFApixels.DragonECS
 {
     #region Interfaces
     [MetaName(nameof(PreInit))]
+    [MetaColor(MetaColor.Orange)]
     [BindWithEcsRunner(typeof(EcsPreInitProcessRunner))]
     public interface IEcsPreInitProcess : IEcsProcess
     {
         void PreInit();
     }
     [MetaName(nameof(Init))]
+    [MetaColor(MetaColor.Orange)]
     [BindWithEcsRunner(typeof(EcsInitProcessRunner))]
     public interface IEcsInitProcess : IEcsProcess
     {
         void Init();
     }
     [MetaName(nameof(Run))]
+    [MetaColor(MetaColor.Orange)]
     [BindWithEcsRunner(typeof(EcsRunProcessRunner))]
     public interface IEcsRunProcess : IEcsProcess
     {
         void Run();
     }
     [MetaName(nameof(Destroy))]
+    [MetaColor(MetaColor.Orange)]
     [BindWithEcsRunner(typeof(EcsDestroyProcessRunner))]
     public interface IEcsDestroyProcess : IEcsProcess
     {

src/Collections/EcsGroup.cs

@@ -23,6 +23,11 @@ namespace DCFApixels.DragonECS
 
         #region Properties
         public bool IsNull => _source == null;
+        public int WorldID
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _source.World.id;
+        }
         public EcsWorld World
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -116,6 +121,11 @@ namespace DCFApixels.DragonECS
         internal bool _isReleased = true;
 
         #region Properties
+        public int WorldID
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _source.id;
+        }
         public EcsWorld World
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -619,7 +629,7 @@ namespace DCFApixels.DragonECS
                 yield return _dense[i];
         }
         public LongsIterator GetLongs() => new LongsIterator(this);
-        public ref struct Enumerator
+        public struct Enumerator : IEnumerator<int>
         {
             private readonly int[] _dense;
             private readonly int _count;
@@ -636,8 +646,13 @@ namespace DCFApixels.DragonECS
                 [MethodImpl(MethodImplOptions.AggressiveInlining)]
                 get => _dense[_index];
             }
+            object IEnumerator.Current => Current;
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             public bool MoveNext() => ++_index <= _count; // <= потму что отсчет начинается с индекса 1 //_count < _dense.Length дает среде понять что проверки на выход за границы не нужны
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            public void Dispose() { }
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            public void Reset() { }
         }
         public readonly struct LongsIterator : IEnumerable<entlong>
         {
@@ -680,25 +695,6 @@ namespace DCFApixels.DragonECS
         }
         #endregion
 
-        #region Object
-        public override string ToString() => $"group{{{string.Join(", ", _dense.Skip(1).Take(_count))}}}";
-        #endregion
-
-        #region OtherMethods
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public int First() => _dense[1];
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public int Last() => _dense[_count];
-        #endregion
-
-        #region OnWorldResize
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        internal void OnWorldResize(int newSize)
-        {
-            Array.Resize(ref _sparse, newSize);
-        }
-        #endregion
-
         #region Convertions
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static implicit operator EcsReadonlyGroup(EcsGroup a) => a.Readonly;
@@ -706,7 +702,26 @@ namespace DCFApixels.DragonECS
         public static implicit operator ReadOnlySpan<int>(EcsGroup a) => a.ToSpan();
         #endregion
 
-        #region DebuggerProxy
+        #region Other
+        public override string ToString()
+        {
+            return $"group{{{string.Join(", ", _dense.Skip(1).Take(_count))}}}";
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public int First()
+        {
+            return _dense[1];
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public int Last()
+        {
+            return _dense[_count];
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal void OnWorldResize(int newSize)
+        {
+            Array.Resize(ref _sparse, newSize);
+        }
         internal class DebuggerProxy
         {
             private EcsGroup _group;
@@ -726,7 +741,6 @@ namespace DCFApixels.DragonECS
             public int Count => _group.Count;
             public int CapacityDense => _group.CapacityDense;
             public int CapacitySparce => _group.CapacitySparce;
-
             public override string ToString() => _group.ToString();
             public DebuggerProxy(EcsGroup group) => _group = group;
         }

src/Collections/EcsSpan.cs

@@ -0,0 +1,81 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+
+namespace DCFApixels.DragonECS
+{
+    public readonly ref struct EcsSpan
+    {
+        private readonly int _worldID;
+        private readonly ReadOnlySpan<int> _values;
+
+        #region Properties
+        public int WorldID => _worldID;
+        public EcsWorld World => EcsWorld.GetWorld(_worldID);
+        public int Length => _values.Length;
+        public bool IsEmpty => _values.IsEmpty;
+        public readonly int this[int index]
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _values[index];
+        }
+        #endregion
+
+        #region Constructors
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal EcsSpan(int worldID, ReadOnlySpan<int> span)
+        {
+            _worldID = worldID;
+            _values = span;
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal EcsSpan(int worldID, int[] array)
+        {
+            _worldID = worldID;
+            _values = array;
+        }
+        internal EcsSpan(int worldID, int[] array, int length)
+        {
+            _worldID = worldID;
+            _values = new ReadOnlySpan<int>(array, 0, length);
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal EcsSpan(int worldID, int[] array, int start, int length)
+        {
+            _worldID = worldID;
+            _values = new ReadOnlySpan<int>(array, start, length);
+        }
+        #endregion
+
+        #region Object
+#pragma warning disable CS0809 // Устаревший член переопределяет неустаревший член
+        [Obsolete($"Equals() on {nameof(EcsSpan)} will always throw an exception. Use the equality operator instead.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public override bool Equals(object obj) => throw new NotSupportedException();
+        [Obsolete($"GetHashCode() on {nameof(EcsSpan)} will always throw an exception.")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
+        public override int GetHashCode() => throw new NotSupportedException();
+#pragma warning restore CS0809 // Устаревший член переопределяет неустаревший член
+        public override string ToString() => _values.ToString();
+        #endregion
+
+        #region operators
+        public static bool operator ==(EcsSpan left, EcsSpan right) => left._values == right._values;
+        public static bool operator !=(EcsSpan left, EcsSpan right) => left._values != right._values;
+        #endregion
+
+        #region Enumerator
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public ReadOnlySpan<int>.Enumerator GetEnumerator() => _values.GetEnumerator();
+        #endregion
+
+        #region Other
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public EcsSpan Slice(int start) => new EcsSpan(_worldID, _values.Slice(start));
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public EcsSpan Slice(int start, int length) => new EcsSpan(_worldID, _values.Slice(start, length));
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public int[] ToArray() => _values.ToArray();
+        #endregion
+    }
+}

src/EcsAspect.cs

@@ -334,12 +334,14 @@ namespace DCFApixels.DragonECS
     #region Iterator
     public ref struct EcsAspectIterator
     {
+        public readonly int worldID;
         public readonly EcsMask mask;
         private EcsReadonlyGroup _sourceGroup;
         private Enumerator _enumerator;
 
         public EcsAspectIterator(EcsAspect aspect, EcsReadonlyGroup sourceGroup)
         {
+            worldID = aspect.World.id;
             mask = aspect.mask; 
             _sourceGroup = sourceGroup;
             _enumerator = default;
@@ -361,6 +363,30 @@ namespace DCFApixels.DragonECS
             while (enumerator.MoveNext())
                 group.AddInternal(enumerator.Current);
         }
+        public int CopyTo(ref int[] array)
+        {
+            var enumerator = GetEnumerator();
+            int count = 0;
+            while (enumerator.MoveNext())
+            {
+                if(array.Length <= count)
+                    Array.Resize(ref array, array.Length << 1);
+                array[count++] = enumerator.Current;
+            }
+            return count;
+        }
+        public EcsSpan CopyToSpan(ref int[] array)
+        {
+            var enumerator = GetEnumerator();
+            int count = 0;
+            while (enumerator.MoveNext())
+            {
+                if (array.Length <= count)
+                    Array.Resize(ref array, array.Length << 1);
+                array[count++] = enumerator.Current;
+            }
+            return new EcsSpan(worldID, array, count);
+        }
 
         #region object
         public override string ToString()

src/EcsRunner.cs

@@ -239,7 +239,7 @@ namespace DCFApixels.DragonECS
                 _filter = null;
                 OnDestroy();
             }
-            protected virtual void OnSetup() { }
+            protected virtual void OnSetup() { } //rename to OnInitialize
             protected virtual void OnDestroy() { }
         }
     }

src/EcsWorld.cs

@@ -141,6 +141,10 @@ namespace DCFApixels.DragonECS
         {
             return GetExecutor<EcsWhereExecutor<TAspect>>().Execute();
         }
+        public EcsSpan WhereSpan<TAspect>() where TAspect : EcsAspect
+        {
+            return GetExecutor<EcsWhereSpanExecutor<TAspect>>().Execute();
+        }
         #endregion
 
         #region Entity

src/Executors/EcsQueryExecutor.cs

@@ -1,15 +1,31 @@
-namespace DCFApixels.DragonECS
+using System.Runtime.CompilerServices;
+
+namespace DCFApixels.DragonECS
 {
     public abstract class EcsQueryExecutor
     {
-        private EcsWorld _world;
+        private EcsWorld _source;
-        public EcsWorld World => _world;
+        public int WorldID
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _source.id;
+        }
+        public EcsWorld World
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _source;
+        }
+        public abstract long Version { get; }
         internal void Initialize(EcsWorld world)
         {
-            _world = world;
+            _source = world;
             OnInitialize();
         }
-        internal void Destroy() => OnDestroy();
+        internal void Destroy()
+        {
+            OnDestroy();
+            _source = null;
+        }
         protected abstract void OnInitialize();
         protected abstract void OnDestroy();
     }

src/Executors/EcsWhereExecutor.cs

@@ -1,19 +1,29 @@
-namespace DCFApixels.DragonECS
+using System.Runtime.CompilerServices;
+
+namespace DCFApixels.DragonECS
 {
     public sealed class EcsWhereExecutor<TAspect> : EcsQueryExecutor where TAspect : EcsAspect
     {
         private TAspect _aspect;
         private EcsGroup _filteredGroup;
 
-        private long _executeVersion;
+        private long _version;
 
 #if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
-        private EcsProfilerMarker _executeWhere = new EcsProfilerMarker("Where");
+        private readonly EcsProfilerMarker _executeMarker = new EcsProfilerMarker("Where");
 #endif
 
         #region Properties
-        public TAspect Aspect => _aspect;
+        public TAspect Aspect
-        internal long ExecuteVersion => _executeVersion;
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _aspect;
+        }
+        public sealed override long Version
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _version;
+        }
         #endregion
 
         #region OnInitialize/OnDestroy
@@ -29,19 +39,80 @@
         #endregion
 
         #region Methods
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public EcsReadonlyGroup Execute() => ExecuteFor(_aspect.World.Entities);
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public EcsReadonlyGroup ExecuteFor(EcsReadonlyGroup sourceGroup)
         {
 #if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
-            _executeWhere.Begin();
+            _executeMarker.Begin();
             if (sourceGroup.IsNull) throw new System.ArgumentNullException();//TODO составить текст исключения. 
+            if (sourceGroup.WorldID != WorldID) throw new System.ArgumentException();//TODO составить текст исключения. 
 #endif
+            unchecked { _version++; }
             _aspect.GetIteratorFor(sourceGroup).CopyTo(_filteredGroup);
 #if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
-            _executeWhere.End();
+            _executeMarker.End();
 #endif
             return _filteredGroup.Readonly;
         }
         #endregion
     }
+
+
+
+
+    public sealed class EcsWhereSpanExecutor<TAspect> : EcsQueryExecutor where TAspect : EcsAspect
+    {
+        private TAspect _aspect;
+        private int[] _filteredEntities;
+
+        private long _version;
+
+#if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
+        private readonly EcsProfilerMarker _executeMarker = new EcsProfilerMarker("Where");
+#endif
+
+        #region Properties
+        public TAspect Aspect
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _aspect;
+        }
+        public sealed override long Version
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get => _version;
+        }
+        #endregion
+
+        #region OnInitialize/OnDestroy
+        protected sealed override void OnInitialize()
+        {
+            _aspect = World.GetAspect<TAspect>();
+            _filteredEntities = new int[32];
+        }
+        protected sealed override void OnDestroy() { }
+        #endregion
+
+        #region Methods
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public EcsSpan Execute() => ExecuteFor(_aspect.World.Entities);
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public EcsSpan ExecuteFor(EcsReadonlyGroup sourceGroup)
+        {
+#if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
+            _executeMarker.Begin();
+            if (sourceGroup.IsNull) throw new System.ArgumentNullException();//TODO составить текст исключения. 
+            if (sourceGroup.WorldID != WorldID) throw new System.ArgumentException();//TODO составить текст исключения. 
+#endif
+            unchecked { _version++; }
+            EcsSpan result = _aspect.GetIteratorFor(sourceGroup).CopyToSpan(ref _filteredEntities);
+#if (DEBUG && !DISABLE_DEBUG) || ENABLE_DRAGONECS_ASSERT_CHEKS
+            _executeMarker.End();
+#endif
+            return result;
+        }
+        #endregion
+    }
 }

src/Utils/GenericEnumerable.cs

@@ -0,0 +1,21 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+
+namespace DCFApixels.DragonECS.Internal
+{
+    public readonly struct GenericEnumerable<T, TEnumerator> : IEnumerable<T> where TEnumerator : IEnumerator<T>
+    {
+        public readonly TEnumerator _enumerator;
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public GenericEnumerable(TEnumerator enumerator) => _enumerator = enumerator;
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TEnumerator GetEnumerator() => _enumerator;
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        IEnumerator<T> IEnumerable<T>.GetEnumerator() => _enumerator;
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        IEnumerator IEnumerable.GetEnumerator() => _enumerator;
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static implicit operator GenericEnumerable<T, TEnumerator>(TEnumerator enumerator) => new GenericEnumerable<T, TEnumerator>(enumerator);
+    }
+}

src/Utils/ReadOnlySpanDummy.cs

@@ -38,13 +38,13 @@ namespace DCFApixels.DragonECS
         #endregion
 
         #region Constructors
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public ReadOnlySpan(T[] array)
         {
             _array = array ?? Array.Empty<T>();
             _start = 0;
             _length = array.Length;
         }
-
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public ReadOnlySpan(T[] array, int start, int length)
         {