Engine - ECS: make TreeNode blittable

friflo · Jul 19, 2024 · 06dbf6c · 06dbf6c
1 parent 1cf975a
commit 06dbf6c
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/Engine/src/ECS/Components/TreeNode.cs b/Engine/src/ECS/Components/TreeNode.cs
@@ -16,7 +16,6 @@ public struct TreeNode : IComponent    // todo should be internal
 
 //  [Browse(Never)] internal    int         parentId;   //  4   0 if entity has no parent
                     internal    IdArray     childIds;   //  8
-                    internal    int[]       dummy;      //  8  todo remove
 
     /// same as <see cref="IdArrayExtensions.GetSpan"/>
     public ReadOnlySpan<int>  GetChildIds(EntityStore store)

diff --git a/Engine/src/ECS/Entity/Store/Entities.cs b/Engine/src/ECS/Entity/Store/Entities.cs
@@ -81,7 +81,10 @@ internal int CreateEntityInternal(Archetype archetype, int id)
     /// <summary>
     /// Create and return a clone of the passed <paramref name="entity"/> in the store.
     /// </summary>
-    /// <returns></returns>
+    /// <remarks>
+    /// Child entities of the passed <paramref name="entity"/> are not copied to the cloned entity.<br/>
+    /// If doing this these child entities would be children of the passed entity <b>and</b> the clone.
+    /// </remarks>
     public Entity CloneEntity(Entity entity)
     {
         var archetype   = entity.archetype ?? throw EntityNullException(entity);
@@ -96,6 +99,9 @@ public Entity CloneEntity(Entity entity)
             var scriptTypeByType    = Static.EntitySchema.ScriptTypeByType;
             // CopyComponents() must be used only in case all component types are blittable
             Archetype.CopyComponents(archetype, entity.compIndex, clone.compIndex);
+            if (clone.HasComponent<TreeNode>()) {
+                clone.GetComponent<TreeNode>() = default;   // clear child ids. See child entities note in remarks.
+            }
             // --- clone scripts
             foreach (var script in entity.Scripts) {
                 var scriptType      = scriptTypeByType[script.GetType()];
@@ -110,7 +116,7 @@ public Entity CloneEntity(Entity entity)
 
             // --- deserialize DataEntity
             dataBuffer.pid      = IdToPid(clone.Id);
-            dataBuffer.children = null; // child ids are not copied. If doing this these children would have two parents.
+            dataBuffer.children = null;                     // clear children. See child entities note in remarks.
             // convert will use entity created above
             converter.DataEntityToEntity(dataBuffer, this, out string error); // error == null. No possibility for mapping errors
             AssertNoError(error);