Mutate Concrete Node Data

The typed nodes in the hierarchy are what you pass to runtime access closures. Start with direct Sprite2D data:

with_node_mut!(ctx, Sprite2D, node_id, |sprite| {    sprite.texture_id = TextureID::new(42);});

Deref Inheritance

Descendant nodes include a base field of their ancestor type and implement Deref/DerefMut. Take Sprite2D and Node2D for example:

pub struct Sprite2D {    pub base: Node2D,    pub texture_id: TextureID,} impl Deref for Sprite2D {    type Target = Node2D;    fn deref(&self) -> &Self::Target { &self.base }} impl DerefMut for Sprite2D {    fn deref_mut(&mut self) -> &mut Self::Target { &mut self.base }}

Deref access is resolved at compile time, so there is no runtime overhead. When you have a Sprite2D, you treat it as also having Node2D fields like position and visibility, so those fields are used as if they are native on the concrete node even though they come through deref.

with_node_mut!(ctx, Sprite2D, node_id, |sprite| {    // Sprite2D field    sprite.texture_id = TextureID::new(7);     // Node2D fields via Deref/DerefMut    sprite.position.x += 12.0;    sprite.visible = true;    sprite.z_index = 3;});