feat: loading and splash screens

Cargo.toml

@@ -24,14 +24,16 @@ default = [ # Only in debug
 release = [ # Only in release (build with --release --no-default-features --features release)
   "bevy_embedded_assets",
   "common",
+  "loading",
   "tts",
 ]
-common = ["input", "menu", "persist", "ui"]
+common = ["menu", "persist"]
 
 3d_camera = []
 input = ["leafwing-input-manager"]
-menu = ["navigation", "input"]
-navigation = ["bevy-alt-ui-navigation-lite"]
+loading = ["ui"]
+menu = ["navigation", "input", "ui"]
+navigation = ["bevy-alt-ui-navigation-lite", "ui"]
 persist = ["bevy-persistent"]
 pixel_perfect = []
 resizable = []

src/assets.rs

@@ -16,7 +16,7 @@ pub struct AssetLoaderPlugin;
 impl Plugin for AssetLoaderPlugin {
     fn build(&self, app: &mut App) {
         app.insert_resource(LoadingData::default())
-            .add_systems(Startup, load_core)
+            .add_systems(OnEnter(GameState::Startup), load_core)
             .add_systems(
                 OnEnter(GameState::Loading),
                 load_example,
@@ -62,7 +62,7 @@ pub struct ExampleAssets {
 // Systems
 // ·······
 
-fn load_core(mut cmd: Commands, asset_server: Res<AssetServer>) {
+pub(crate) fn load_core(mut cmd: Commands, asset_server: Res<AssetServer>) {
     // They use the asset server directly
     let assets = CoreAssets {
         bevy_icon: asset_server.load(if cfg!(feature = "pixel_perfect") {
@@ -99,7 +99,7 @@ fn load_example(
 // ·······
 
 #[derive(Resource, Debug, Default)]
-struct LoadingData {
+pub(crate) struct LoadingData {
     assets: Vec<UntypedHandle>,
     loaded: usize,
     total: usize,
@@ -118,7 +118,7 @@ impl LoadingData {
     }
 
     /// Returns the current loaded assets and the total assets registered
-    fn current(&mut self, asset_server: &AssetServer) -> (usize, usize) {
+    pub(crate) fn current(&mut self, asset_server: &AssetServer) -> (usize, usize) {
         // Find assets that have already been loaded and remove them from the list
         self.assets.retain(|asset| {
             let Some(state) = asset_server.get_load_states(asset) else { return true };
@@ -142,10 +142,21 @@ impl LoadingData {
 }
 
 fn check_load_state(
+    #[cfg(feature = "loading")] curr_loading_state: Res<
+        State<crate::ui::loading::LoadingScreenState>,
+    >,
     mut next_state: ResMut<NextState<GameState>>,
     mut loading_data: ResMut<LoadingData>,
     asset_server: Res<AssetServer>,
 ) {
+    #[cfg(feature = "loading")]
+    if !matches!(
+        curr_loading_state.get(),
+        crate::ui::loading::LoadingScreenState::Loading
+    ) {
+        return;
+    }
+
     let (loaded, total) = loading_data.current(&asset_server);
     if loaded == total {
         next_state.set(if cfg!(feature = "menu") { GameState::Menu } else { GameState::Play });

src/camera.rs

@@ -2,7 +2,10 @@
 
 use bevy::prelude::*;
 
-use crate::data::{GameOptions, Persistent};
+use crate::{
+    data::{init_data, GameOptions, Persistent},
+    GameState,
+};
 
 /// The luminance of the background color
 pub const BACKGROUND_LUMINANCE: f32 = 0.05;
@@ -18,7 +21,10 @@ pub struct CameraPlugin;
 
 impl Plugin for CameraPlugin {
     fn build(&self, app: &mut App) {
-        app.add_systems(Startup, init);
+        app.add_systems(
+            OnEnter(GameState::Startup),
+            init.after(init_data),
+        );
     }
 }
 

src/data.rs

@@ -7,6 +7,7 @@ use serde::{Deserialize, Serialize};
 
 #[cfg(not(feature = "persist"))]
 pub use self::alt::Persistent;
+use crate::GameState;
 
 // ······
 // Plugin
@@ -19,7 +20,7 @@ pub struct DataPlugin;
 
 impl Plugin for DataPlugin {
     fn build(&self, app: &mut App) {
-        app.add_systems(PreStartup, init);
+        app.add_systems(OnEnter(GameState::Startup), init_data);
     }
 }
 
@@ -102,7 +103,7 @@ mod alt {
 // Systems
 // ·······
 #[cfg(feature = "persist")]
-fn init(mut cmd: Commands) {
+pub(crate) fn init_data(mut cmd: Commands) {
     let path = std::path::Path::new(if cfg!(target_arch = "wasm32") { "local" } else { ".data" });
     info!("{:?}", path);
 
@@ -132,7 +133,7 @@ fn init(mut cmd: Commands) {
 }
 
 #[cfg(not(feature = "persist"))]
-fn init(mut cmd: Commands) {
+pub(crate) fn init_data(mut cmd: Commands) {
     cmd.insert_resource(Persistent(GameOptions::default()));
     cmd.insert_resource(Persistent(SaveData::default()));
 }

src/input.rs

@@ -4,6 +4,8 @@ use bevy::prelude::*;
 pub use leafwing_input_manager::prelude::ActionState;
 use leafwing_input_manager::prelude::*;
 
+use crate::GameState;
+
 // ······
 // Plugin
 // ······
@@ -16,12 +18,15 @@ pub struct InputPlugin;
 impl Plugin for InputPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins(InputManagerPlugin::<Action>::default())
-            .add_systems(Startup, init);
+            .add_systems(
+                OnEnter(GameState::Play),
+                init.run_if(run_once()),
+            );
 
         #[cfg(feature = "menu")]
         app.add_systems(
             Update,
-            handle_input.run_if(in_state(crate::GameState::Play)),
+            handle_input.run_if(in_state(GameState::Play)),
         );
     }
 }

src/lib.rs

@@ -22,9 +22,13 @@ use bevy::{log::LogPlugin, prelude::*, window::WindowResolution};
 /// be deleted automatically when the state ends
 #[derive(States, Debug, Default, Clone, Eq, PartialEq, Hash)]
 pub enum GameState {
-    /// The game starts on the loading state
-    /// It stays here until all the relevant assets are ready
+    /// The game starts on the setup state
+    /// This runs before *anything*, including Startup
+    /// It inmediately transitions to loading, so only use it for OnEnter
     #[default]
+    Startup,
+    /// After startup it transitions to loading, which handles splash screens
+    /// and assets. It stays here until all the relevant assets are ready
     Loading,
     /// The main menu of the game, everything is paused
     Menu,
@@ -160,5 +164,22 @@ impl Plugin for GamePlugin {
 
         #[cfg(feature = "ui")]
         app.add_plugins(ui::UiPlugin);
+
+        app.add_systems(
+            Update,
+            finish_setup.run_if(in_state(GameState::Startup)),
+        );
     }
 }
+
+// ·······
+// Systems
+// ·······
+
+/// This system inmediately transitions Startup to Loading, ensuring that the
+/// first only lasts for a frame and that only the OnEnter and OnExit schedules
+/// are valid. This is a replacement for PreStartup and PostStartup that works
+/// with the new 0.14 schedule ordering.
+fn finish_setup(mut next_state: ResMut<NextState<GameState>>) {
+    next_state.set(GameState::Loading);
+}

src/ui.rs

@@ -3,8 +3,10 @@
 use bevy::prelude::*;
 use sickle_ui::{prelude::*, SickleUiPlugin};
 
-use crate::camera::FinalCamera;
+use crate::{camera::FinalCamera, GameState};
 
+#[cfg(feature = "loading")]
+pub mod loading;
 #[cfg(feature = "menu")]
 pub mod menu;
 #[cfg(feature = "navigation")]
@@ -13,6 +15,8 @@ pub mod navigation;
 pub mod tts;
 pub mod widgets;
 
+const UI_GAP: Val = Val::Px(16.);
+
 // ······
 // Plugin
 // ······
@@ -24,7 +28,10 @@ pub struct UiPlugin;
 impl Plugin for UiPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins(SickleUiPlugin)
-            .add_systems(PostStartup, init);
+            .add_systems(OnExit(GameState::Startup), init);
+
+        #[cfg(feature = "loading")]
+        app.add_plugins(loading::LoadingScreenPlugin);
 
         #[cfg(feature = "menu")]
         app.add_plugins(menu::MenuPlugin);