fixed relationship deletion

plugins/TinyEcs.Plugins/Relationship.cs

@@ -13,6 +13,9 @@ public struct Relationship
 	public readonly RelationshipIterator Children(World world) => new (world, First);
 }
 
+public readonly struct Parent { }
+public readonly struct Child { }
+
 public ref struct RelationshipIterator
 {
 	private readonly World _world;
@@ -40,9 +43,6 @@ public bool MoveNext()
 	public readonly RelationshipIterator GetEnumerator() => this;
 }
 
-public readonly struct Parent { }
-public readonly struct Child { }
-
 public static class RelationshipPlugin
 {
 	[ModuleInitializer]
@@ -51,7 +51,27 @@ internal static void ModuleInit()
 		World.OnPluginInitialization += world => {
 			world.Component<Parent>();
 			world.Component<Child>();
-			world.OnEntityDeleted += e => e.ClearChildren();
+			world.Component<Relationship>();
+			world.OnEntityDeleted += e => {
+				if (e.Has<Parent>())
+				{
+					e.World.Merge();
+
+					foreach (var childId in e.Children())
+					{
+						e.World.DeferredEntity(childId).Delete();
+					}
+
+					e.World.Merge();
+				}
+
+				if (e.Has<Child>())
+				{
+					ref var rel = ref e.Get<Relationship>();
+					if (rel.Parent != 0 && e.World.Exists(rel.Parent))
+						e.World.Entity(rel.Parent).RemoveChild(e);
+				}
+			};
 		};
 	}
 

samples/MyBattleground/Program.cs

@@ -12,16 +12,15 @@
 	.Set<Position>(new Position() {X = 2})
 	.Set<Velocity>(new Velocity());
 
-
 ecs.Filter<(Position, Velocity)>()
 	.Query((EntityView entity) => {
 		Console.WriteLine(entity.Name());
 	});
 
 
 
-var e2 = ecs.Entity("Main");
-ref var pp = ref e2.Get<Position>();
+// var e2 = ecs.Entity("Main");
+// ref var pp = ref e2.Get<Position>();
 
 var child = ecs.Entity("child 0");
 var child2 = ecs.Entity("child 1");
@@ -68,21 +67,34 @@
 
 Console.WriteLine();
 
-e.ClearChildren();
-ecs.Filter<With<Parent>>().Query((EntityView entity, ref Relationship relation) => {
-	Console.WriteLine("parent {0} has {1} children", entity.Name(), relation.Count);
-});
+// e.ClearChildren();
+// ecs.Filter<With<Parent>>().Query((EntityView entity, ref Relationship relation) => {
+// 	Console.WriteLine("parent {0} has {1} children", entity.Name(), relation.Count);
+// });
+
+for (var i = 0; i < 5; ++i)
+{
+	var c = ecs.Entity();
+	Console.WriteLine("Add {0}", c.ID);
+	e.AddChild(c);
+}
+
+foreach (var childId in e.Children())
+{
+	Console.WriteLine("child {0}", childId);
+}
 
 e.Delete();
+var exists = e.Exists();
 
-	ecs.Entity()
-		 .Set<Position>(new Position())
-		 .Set<Velocity>(new Velocity());
+ecs.Entity()
+	.Set<Position>(new Position())
+	.Set<Velocity>(new Velocity());
 
 for (int i = 0; i < ENTITIES_COUNT / 1; i++)
 	ecs.Entity()
-		 .Set<Position>(new Position())
-		 .Set<Velocity>(new Velocity())
+		.Set<Position>(new Position())
+		.Set<Velocity>(new Velocity())
 		//  .Set<PlayerTag>()
 		//  .Set<Dogs>()
 		//  .Set<Likes>()
@@ -97,7 +109,8 @@
 	//var cur = (start - last) / 1000f;
 	for (int i = 0; i < 3600; ++i)
 	{
-		ecs.Filter<With<PlayerTag>>()
+		ecs
+		//.Filter<With<PlayerTag>>()
 			.Query((ref Position pos, ref Velocity vel) =>
 			{
 				pos.X *= vel.X;

src/World.cs

@@ -43,7 +43,7 @@ public World()
 
     public ReadOnlySpan<Archetype> Archetypes => _archetypes.AsSpan(0, _archetypeCount);
 
-    public CommandEntityView DeferredEntity() => _commands.Entity();
+    public CommandEntityView DeferredEntity(EcsID id = default) => _commands.Entity(id);
 
     public void Merge() => _commands.Merge();