refactor: let the bevy rewrite begin: mostly working model nodes

Signed-off-by: Schmarni <marnistromer@gmail.com>

src/nodes/spatial/mod.rs

@@ -9,16 +9,85 @@ use crate::core::client::Client;
 use crate::core::error::Result;
 use crate::core::registry::Registry;
 use crate::nodes::{Node, OWNED_ASPECT_ALIAS_INFO};
+use bevy::ecs::entity_disabling::Disabled;
+use bevy::prelude::Transform as BevyTransform;
+use bevy::prelude::*;
 use color_eyre::eyre::OptionExt;
 use glam::{Mat4, Quat, Vec3, vec3a};
 use mint::Vector3;
 use parking_lot::Mutex;
 use rustc_hash::FxHashMap;
 use std::fmt::Debug;
+use std::sync::atomic::Ordering;
 use std::sync::{Arc, OnceLock, Weak};
 use std::{f32, ptr};
 use stereokit_rust::maths::Bounds;
 
+pub struct SpatialNodePlugin;
+impl Plugin for SpatialNodePlugin {
+	fn build(&self, app: &mut App) {
+		app.add_systems(
+			PostUpdate,
+			(replace_childof, update_spatial_nodes).before(TransformSystem::TransformPropagate),
+		);
+	}
+}
+
+fn update_spatial_nodes(
+	mut query: Query<(Entity, &mut BevyTransform, &SpatialNode, Has<Disabled>)>,
+	cmds: ParallelCommands,
+) {
+	query
+		.par_iter_mut()
+		.for_each(|(entity, mut transform, spatial_node, disabled)| {
+			let Some(spatial) = spatial_node.0.upgrade() else {
+				return;
+			};
+			if !spatial
+				.node()
+				.map(|n| n.enabled.load(Ordering::Relaxed))
+				.unwrap_or(true)
+			{
+				// cmds.command_scope(|mut cmds| {
+				// 	cmds.entity(entity).insert(Visibility::Hidden);
+				// });
+				// return;
+			}
+			let mat4 = spatial.global_transform();
+
+			let scale_zero = mat4.to_scale_rotation_translation().0.length_squared() > 0.0;
+			if scale_zero {
+				// cmds.command_scope(|mut cmds| {
+				// 	cmds.entity(entity).insert(Visibility::Hidden);
+				// });
+			} else if disabled {
+				// cmds.command_scope(|mut cmds| {
+				// 	cmds.entity(entity).insert(Visibility::Visible);
+				// });
+			}
+			*transform = BevyTransform::from_matrix(mat4);
+		});
+}
+
+fn replace_childof(query: Query<(Entity, &ChildOf), With<SpatialNode>>, mut cmds: Commands) {
+	for (entity, parent) in &query {
+		cmds.entity(entity)
+			.insert(NonSpatialChildOf(parent.0))
+			.remove::<ChildOf>();
+	}
+}
+
+#[derive(Component, Default, Debug, PartialEq, Eq)]
+#[relationship_target(relationship = NonSpatialChildOf, linked_spawn)]
+pub struct NonSpatialChildren(Vec<Entity>);
+#[derive(Component, Debug, PartialEq, Eq)]
+#[relationship(relationship_target = NonSpatialChildren)]
+pub struct NonSpatialChildOf(Entity);
+
+#[derive(Clone, Component, Debug)]
+#[require(BevyTransform)]
+pub struct SpatialNode(pub Weak<Spatial>);
+
 stardust_xr_server_codegen::codegen_spatial_protocol!();
 impl Transform {
 	pub fn to_mat4(&self, position: bool, rotation: bool, scale: bool) -> Mat4 {