Channels won't work _easily_ as the Receiver is not Send

I think I'll try using Bevy's event system

src/main.rs

@@ -100,9 +100,8 @@ fn main() -> AppExit {
     .add_systems(OnExit(View::MainMenu), main_menu::exit)
     .add_systems(
         OnEnter(View::LoadingGame),
-        (player::startup, statue::startup, map::spawn),
+        (player::startup, statue::startup, map::init),
     )
-    .add_systems(OnEnter(View::InGame), map::finalize)
     .add_systems(
         OnExit(View::InGame),
         (player::exit, statue::exit, map::exit),
@@ -112,6 +111,7 @@ fn main() -> AppExit {
         (
             load_menu.run_if(in_state(View::LoadingMenu)),
             load_game.run_if(in_state(View::LoadingGame)),
+            map::tile_loaders.run_if(in_state(View::LoadingGame)),
             input::process_input,
             (update,).after(input::process_input),
             (

src/map.rs

@@ -1,3 +1,5 @@
+use std::sync::mpsc::{channel, Receiver};
+
 use crate::{inspector::HideFromInspector, prelude::*};
 use bevy::{
     ecs::{system::SystemState, world::CommandQueue},
@@ -15,57 +17,68 @@ use rand_seeder::Seeder;
 #[derive(Component, Debug)]
 pub struct Tilemap;
 
-#[derive(Component)]
+#[derive(Resource, Debug)]
-struct MapGenTask(Task<CommandQueue>);
+pub struct TileChan(Receiver<TileBundle>);
 
-#[derive(Resource, Deref, DerefMut)]
+#[derive(Component, Debug)]
-struct TileStorageHandle(TileStorage);
+pub struct TileInit(Task<()>);
 
-pub fn spawn(mut commands: Commands, assets: Res<AssetServer>) {
+pub fn init(mut commands: Commands, assets: Res<AssetServer>) {
     // TODO: I'm pretty determined to not have this sieze up the game despite the large number of entities being added. Should work with a "loading" screen and doing this in the background?
 
     let mut rng: Pcg64 = Seeder::from("default_seed").make_rng();
     let size = TilemapSize::new(1024, 1024);
-    let tilemap = commands.spawn((Tilemap, Name::new("Tilemap"))).id();
+    let tile_size = TilemapTileSize::new(16., 16.);
-    commands.insert_resource(TileStorageHandle(TileStorage::empty(size)));
+    let grid_size = TilemapGridSize::new(16., 16.);
-    let pool = AsyncComputeTaskPool::get();
+    let map_type = TilemapType::Square;
-    // this task is for generating tilebundles
+    let texture = TilemapTexture::Single(assets.load("img/Tileset Grass.png"));
-    for x in 0..size.x {
+    let storage = TileStorage::empty(size);
-        for y in 0..size.y {
-            let position = TilePos::new(x, y);
-            let texture_index = TileTextureIndex(if rng.gen_range(0..1000) > 925 {
-                rng.gen_range(0..(16 * 8))
-            } else {
-                0
-            });
-            let task = pool.spawn(async move {
-                let mut command_queue = CommandQueue::default();
-                command_queue.push(move |world: &mut World| {
-                    let mut state = SystemState::<ResMut<TileStorageHandle>>::new(world);
-                    let entity = world
-                        .spawn((
-                            HideFromInspector,
-                            TileBundle {
-                                position,
-                                tilemap_id: TilemapId(tilemap),
-                                texture_index,
-                                ..Default::default()
-                            },
-                        ))
-                        .id();
 
-                    let mut storage = state.get_mut(world);
+    let tilemap = commands
-                    storage.set(&position, entity);
+        .spawn((
+            Tilemap,
+            Name::new("Tilemap"),
+            TilemapBundle {
+                grid_size,
+                map_type,
+                size,
+                storage,
+                texture,
+                tile_size,
+                transform: get_tilemap_center_transform(&size, &grid_size, &map_type, f32::MIN),
+                ..Default::default()
+            },
+        ))
+        .id();
+
+    let pool = AsyncComputeTaskPool::get();
+    let task = pool.spawn(async move {
+        let (tx, rx) = channel::<TileBundle>();
+        for x in 0..size.x {
+            for y in 0..size.y {
+                let position = TilePos::new(x, y);
+                let texture_index = TileTextureIndex(if rng.gen_range(0..1000) > 925 {
+                    rng.gen_range(0..(16 * 8))
+                } else {
+                    0
                 });
-                command_queue
+                tx.send(TileBundle {
-            });
+                    position,
-            commands.entity(tilemap).insert(MapGenTask(task));
+                    tilemap_id: TilemapId(tilemap),
+                    texture_index,
+                    ..Default::default()
+                })
+                .unwrap();
+            }
         }
-    }
+        tx
+    });
+
+    commands.entity(tilemap).insert(TileInit(task));
 }
 
-fn load(mut commands: Commands, mut tasks: Query<&mut MapGenTask>) {
+pub fn tile_loaders(mut commands: Commands, mut tasks: Query<&mut TileInit>) {
-    // to avoid locking up the universe we only want to handle a certain number per iteration (Update)
+    // TODO: to avoid locking up the universe we only want to handle a certain number per iteration (Update)
     for mut task in &mut tasks {
         if let Some(mut commands_queue) = block_on(future::poll_once(&mut task.0)) {
             // append the returned command queue to have it execute later
@@ -74,38 +87,6 @@ fn load(mut commands: Commands, mut tasks: Query<&mut MapGenTask>) {
     }
 }
 
-pub fn finalize(
-    // mut commands: Commands,
-    // mut storage: Res<TileStorageHandle>,
-    // tilemap: Query<Entity, With<Tilemap>>,
-    // assets: Res<AssetServer>,
-    world: &mut World,
-) {
-    let storage = world.remove_resource::<TileStorageHandle>().unwrap();
-
-    // TODO: dedupe with load
-    let size = TilemapSize::new(1024, 1024);
-    let tile_size = TilemapTileSize::new(16., 16.);
-    let grid_size = TilemapGridSize::new(16., 16.);
-    let map_type = TilemapType::Square;
-    let storage = storage.0;
-    let mut query = world.query_filtered::<Entity, With<Tilemap>>();
-    let tilemap = query.single(world);
-    let assets = world.resource::<AssetServer>();
-    let texture = TilemapTexture::Single(assets.load("img/Tileset Grass.png"));
-    let mut commands = world.commands();
-    commands.entity(tilemap).insert(TilemapBundle {
-        grid_size,
-        map_type,
-        size,
-        storage,
-        texture,
-        tile_size,
-        transform: get_tilemap_center_transform(&size, &grid_size, &map_type, f32::MIN),
-        ..Default::default()
-    });
-}
-
 pub fn exit(mut commands: Commands, q: Query<Entity, With<Tilemap>>) {
     for id in q.iter() {
         commands.entity(id).despawn_recursive();