scene: some cleanup

lyra-scene/src/lib.rs

@@ -51,7 +51,7 @@ impl<'a, T> DerefMut for MutCow<'a, T> {
 /// This SceneGraph is special in the sense that it is literally just an ECS world with methods
 /// implemented for it that make it easier to use for a SceneGraph.
 //#[derive(Default)]
-pub struct SceneGraph<'a> {
+pub struct SceneGraph<'a>  {
     pub(crate) world: MutCow<'a, World>,
     root_node: SceneNode,
 }
@@ -162,6 +162,13 @@ impl<'a> SceneGraph<'a> {
         world_add_child_node(&mut self.world, parent, local_transform, bundle)
     }
 
+    pub fn add_empty_node_under(&mut self, parent: &SceneNode, local_transform: Transform) -> SceneNode {
+        let e = self.world.spawn((SceneNodeFlag, local_transform));
+        self.world.add_relation(e, ChildOf, parent.entity());
+
+        SceneNode::new(Some(parent.entity()), e)
+    }
+
     /// Traverses down the SceneGraph, calling `callback` with each SceneNode and its world transform.
     /// 
     /// The traversal does not include the root scene node.
@@ -189,6 +196,10 @@ impl<'a> SceneGraph<'a> {
             self.traverse_down_from(node, callback);
         }
     }
+
+    pub fn root_node(&self) -> SceneNode {
+        self.root_node.clone()
+    }
 }
 
 /// Add a node under a parent node.
@@ -256,7 +267,7 @@ pub mod tests {
         });
     }
 
-    #[test]
+    /* #[test]
     fn inserting_and_from_world() {
         let v2s = vec![Vec3::new(10.0, 10.0, 10.0), Vec3::new(50.0, 50.0, 50.0)];
 
@@ -301,5 +312,5 @@ pub mod tests {
 
             idx += 1;
         });
-    }
+    } */
 }