Make superflat option per client rather than per world

examples/combat.rs

@@ -87,7 +87,6 @@ impl Config for Game {
     fn init(&self, server: &mut Server<Self>) {
         let (_, world) = server.worlds.insert(DimensionId::default(), ());
         server.state = Some(server.player_lists.insert(()).0);
-        world.meta.set_flat(true);
 
         let min_y = server.shared.dimension(DimensionId::default()).min_y;
 
@@ -117,7 +116,7 @@ impl Config for Game {
     }
 
     fn update(&self, server: &mut Server<Self>) {
-        let (world_id, world) = server.worlds.iter_mut().next().unwrap();
+        let (world_id, _) = server.worlds.iter_mut().next().unwrap();
 
         let current_tick = server.shared.current_tick();
 
@@ -152,6 +151,7 @@ impl Config for Game {
                 client.state.extra_knockback = true;
 
                 client.spawn(world_id);
+                client.set_flat(true);
                 client.set_game_mode(GameMode::Survival);
                 client.teleport(
                     [

examples/conway.rs

@@ -101,7 +101,6 @@ impl Config for Game {
     fn init(&self, server: &mut Server<Self>) {
         let world = server.worlds.insert(DimensionId::default(), ()).1;
         server.state.player_list = Some(server.player_lists.insert(()).0);
-        world.meta.set_flat(true);
 
         for chunk_z in -2..Integer::div_ceil(&(SIZE_X as i32), &16) + 2 {
             for chunk_x in -2..Integer::div_ceil(&(SIZE_Z as i32), &16) + 2 {
@@ -144,6 +143,7 @@ impl Config for Game {
                 }
 
                 client.spawn(world_id);
+                client.set_flat(true);
                 client.teleport(spawn_pos, 0.0, 0.0);
                 client.set_player_list(server.state.player_list.clone());
 

examples/cow_sphere.rs

@@ -81,7 +81,6 @@ impl Config for Game {
     fn init(&self, server: &mut Server<Self>) {
         let (world_id, world) = server.worlds.insert(DimensionId::default(), ());
         server.state.player_list = Some(server.player_lists.insert(()).0);
-        world.meta.set_flat(true);
 
         let size = 5;
         for z in -size..size {
@@ -127,6 +126,7 @@ impl Config for Game {
                 }
 
                 client.spawn(world_id);
+                client.set_flat(true);
                 client.set_game_mode(GameMode::Creative);
                 client.teleport(
                     [

examples/raycast.rs

@@ -76,7 +76,6 @@ impl Config for Game {
     fn init(&self, server: &mut Server<Self>) {
         let (world_id, world) = server.worlds.insert(DimensionId::default(), ());
         server.state = Some(server.player_lists.insert(()).0);
-        world.meta.set_flat(true);
 
         let size = 5;
         for z in -size..size {
@@ -127,6 +126,7 @@ impl Config for Game {
                 }
 
                 client.spawn(world_id);
+                client.set_flat(true);
                 client.set_game_mode(GameMode::Creative);
                 client.teleport(
                     [

examples/terrain.rs

@@ -84,9 +84,8 @@ impl Config for Game {
     }
 
     fn init(&self, server: &mut Server<Self>) {
-        let (_, world) = server.worlds.insert(DimensionId::default(), ());
+        server.worlds.insert(DimensionId::default(), ());
         server.state = Some(server.player_lists.insert(()).0);
-        world.meta.set_flat(true);
     }
 
     fn update(&self, server: &mut Server<Self>) {
@@ -119,6 +118,7 @@ impl Config for Game {
                 }
 
                 client.spawn(world_id);
+                client.set_flat(true);
                 client.set_game_mode(GameMode::Creative);
                 client.teleport([0.0, 200.0, 0.0], 0.0, 0.0);
                 client.set_player_list(server.state.clone());

src/client.rs

@@ -227,6 +227,7 @@ pub struct Client<C: Config> {
 #[bitfield(u16)]
 struct ClientBits {
     spawn: bool,
+    flat: bool,
     teleported_this_tick: bool,
     /// If spawn_position or spawn_position_yaw were modified this tick.
     modified_spawn_position: bool,
@@ -238,7 +239,7 @@ struct ClientBits {
     velocity_modified: bool,
     created_this_tick: bool,
     view_distance_modified: bool,
-    #[bits(6)]
+    #[bits(5)]
     _pad: u8,
 }
 
@@ -325,6 +326,20 @@ impl<C: Config> Client<C> {
         mem::replace(&mut self.new_player_list, id)
     }
 
+    /// Sets if this client sees the world as superflat. Superflat worlds have
+    /// a horizon line lower than normal worlds.
+    ///
+    /// The player must be spawned for changes to take effect.
+    pub fn set_flat(&mut self, flat: bool) {
+        self.bits.set_flat(flat);
+    }
+
+    /// Gets if this client sees the world as superflat. Superflat worlds have
+    /// a horizon line lower than normal worlds.
+    pub fn is_flat(&self) -> bool {
+        self.bits.flat()
+    }
+
     /// Changes the world this client is located in and respawns the client.
     /// This can be used to respawn the client after death.
     ///
@@ -862,7 +877,7 @@ impl<C: Config> Client<C> {
         let current_tick = shared.current_tick();
 
         // Send the join game packet and other initial packets. We defer this until now
-        // so that the user can set the client's location, game mode, etc.
+        // so that the user can set the client's initial location, game mode, etc.
         if self.created_this_tick() {
             if let Some(id) = &self.new_player_list {
                 player_lists
@@ -899,7 +914,7 @@ impl<C: Config> Client<C> {
                 reduced_debug_info: false,
                 enable_respawn_screen: false,
                 is_debug: false,
-                is_flat: world.meta.is_flat(),
+                is_flat: self.bits.flat(),
                 last_death_location: self
                     .death_location
                     .map(|(id, pos)| (ident!("{LIBRARY_NAMESPACE}:dimension_{}", id.0), pos)),
@@ -921,7 +936,7 @@ impl<C: Config> Client<C> {
                     game_mode: self.game_mode(),
                     previous_game_mode: self.game_mode(),
                     is_debug: false,
-                    is_flat: false,
+                    is_flat: self.bits.flat(),
                     copy_metadata: true,
                     last_death_location: None,
                 });
@@ -939,7 +954,7 @@ impl<C: Config> Client<C> {
                     game_mode: self.game_mode(),
                     previous_game_mode: self.game_mode(),
                     is_debug: false,
-                    is_flat: world.meta.is_flat(),
+                    is_flat: self.bits.flat(),
                     copy_metadata: true,
                     last_death_location: self
                         .death_location

src/world.rs

@@ -49,10 +49,7 @@ impl<C: Config> Worlds<C> {
             state,
             spatial_index: SpatialIndex::new(),
             chunks: Chunks::new(self.server.clone(), dim),
-            meta: WorldMeta {
+            meta: WorldMeta { dimension: dim },
-                dimension: dim,
-                is_flat: false,
-            },
         });
 
         (WorldId(id), world)
@@ -136,8 +133,6 @@ pub struct World<C: Config> {
 /// Contains miscellaneous world state.
 pub struct WorldMeta {
     dimension: DimensionId,
-    is_flat: bool,
-    // TODO: time, weather
 }
 
 impl WorldMeta {
@@ -145,18 +140,4 @@ impl WorldMeta {
     pub fn dimension(&self) -> DimensionId {
         self.dimension
     }
-
-    /// Gets if this world is considered a superflat world. Superflat worlds
-    /// have a horizon line at y=0.
-    pub fn is_flat(&self) -> bool {
-        self.is_flat
-    }
-
-    /// Sets if this world is considered a superflat world. Superflat worlds
-    /// have a horizon line at y=0.
-    ///
-    /// Clients already in the world must be respawned to see any changes.
-    pub fn set_flat(&mut self, flat: bool) {
-        self.is_flat = flat;
-    }
 }