From 6e5df25675604b88660a4faca97e99cb84280ed6 Mon Sep 17 00:00:00 2001
From: aligator <me@aligator.dev>
Date: Thu, 11 Apr 2024 20:07:00 +0200
Subject: [PATCH] Add world root

---
 src/voxel_world_internal.rs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/voxel_world_internal.rs b/src/voxel_world_internal.rs
index 10b03c5..2f9d028 100644
--- a/src/voxel_world_internal.rs
+++ b/src/voxel_world_internal.rs
@@ -61,9 +61,13 @@ pub(crate) struct NeedsMaterial<C>(PhantomData<C>);
 
 pub(crate) struct Internals<C>(PhantomData<C>);
 
+#[derive(Component)]
+pub struct WorldRoot<C>(PhantomData<C>);
+
 impl<C: VoxelWorldConfig> Internals<C> {
     /// Init the resources used internally by bevy_voxel_world
     pub fn setup(mut commands: Commands) {
+        commands.spawn(WorldRoot::<C>(PhantomData));
         commands.init_resource::<ChunkMap<C>>();
         commands.init_resource::<ChunkMapInsertBuffer<C>>();
         commands.init_resource::<ChunkMapUpdateBuffer<C>>();
@@ -78,10 +82,14 @@ impl<C: VoxelWorldConfig> Internals<C> {
     pub fn spawn_chunks(
         mut commands: Commands,
         mut chunk_map_write_buffer: ResMut<ChunkMapInsertBuffer<C>>,
+        world_root: Query<Entity, With<WorldRoot<C>>>,
         chunk_map: Res<ChunkMap<C>>,
         configuration: Res<C>,
         camera_info: CameraInfo,
     ) {
+        // Panic if no root exists as it is already inserted in the setup.
+        let world_root = world_root.get_single().unwrap();
+
         let (camera, cam_gtf) = camera_info.single();
         let cam_pos = cam_gtf.translation().as_ivec3();
 
@@ -159,7 +167,7 @@ impl<C: VoxelWorldConfig> Internals<C> {
             let has_chunk = ChunkMap::<C>::contains_chunk(&chunk_position, &chunk_map_read_lock);
 
             if !has_chunk {
-                let chunk = Chunk::<C>::new(chunk_position, commands.spawn(NeedsRemesh).id());
+                let chunk = Chunk::<C>::new(chunk_position, commands.entity(world_root).insert(NeedsRemesh).id());
 
                 chunk_map_write_buffer.push((chunk_position, ChunkData::with_entity(chunk.entity)));