Use a vec of splash screen images

src/screens/splash.rs

@@ -1,5 +1,7 @@
 //! A splash screen that plays briefly at startup.
 
+use std::collections::VecDeque;
+
 use bevy::{
     input::common_conditions::input_just_pressed,
     prelude::*,
@@ -12,6 +14,8 @@ use crate::{theme::prelude::*, AppSet};
 pub(super) fn plugin(app: &mut App) {
     // Spawn splash screen.
     app.insert_resource(ClearColor(SPLASH_BACKGROUND_COLOR));
+    app.init_resource::<SplashScreenImageList>();
+
     app.add_systems(OnEnter(Screen::Splash), spawn_splash);
 
     // Animate splash screen.
@@ -49,11 +53,71 @@ const SPLASH_BACKGROUND_COLOR: Color = Color::srgb(0.157, 0.157, 0.157);
 const SPLASH_DURATION_SECS: f32 = 1.8;
 const SPLASH_FADE_DURATION_SECS: f32 = 0.6;
 
+#[derive(Component)]
+struct SplashScreenContainer;
+
+#[derive(Resource)]
+struct SplashScreenImageList(VecDeque<&'static str>);
+
+impl Default for SplashScreenImageList {
+    fn default() -> Self {
+        // Use paths here rather than an ImageHandle as the loading screen hasn't
+        // run yet. To show your own splash images, replace or add here
+        Self(VecDeque::from_iter(["images/splash.png"].into_iter()))
+    }
+}
 
 fn exit_splash_screen(mut next_screen: ResMut<NextState<Screen>>) {
     next_screen.set(Screen::Loading);
 }
 
+fn splash_image_bundle(asset_server: &AssetServer, path: &'static str) -> impl Bundle {
+    (
+        Name::new("Splash image"),
+        ImageBundle {
+            style: Style {
+                margin: UiRect::all(Val::Auto),
+                width: Val::Percent(70.0),
+                ..default()
+            },
+            image: UiImage::new(asset_server.load_with_settings(
+                // This should be an embedded asset for instant loading, but that is
+                // currently [broken on Windows Wasm builds](https://github.com/bevyengine/bevy/issues/14246).
+                path,
+                |settings: &mut ImageLoaderSettings| {
+                    // Make an exception for the splash image in case
+                    // `ImagePlugin::default_nearest()` is used for pixel art.
+                    settings.sampler = ImageSampler::linear();
+                },
+            )),
+            background_color: BackgroundColor(Color::srgba(0., 0., 0., 0.)),
+            ..default()
+        },
+        UiImageFadeInOut {
+            total_duration: SPLASH_DURATION_SECS,
+            fade_duration: SPLASH_FADE_DURATION_SECS,
+            t: 0.0,
+        },
+    )
+}
+
+fn spawn_splash(
+    mut commands: Commands,
+    splash_images: Res<SplashScreenImageList>,
+    mut next_screen: ResMut<NextState<Screen>>,
+) {
+    if splash_images.0.is_empty() {
+        // if there are no splash images, go directly to the loading screen
+        next_screen.set(Screen::Loading);
+    } else {
+        // spawn the UI root but wait for the first timer tick to show an image
+        commands.ui_root().insert((
+            Name::new("Splash screen container"),
+            BackgroundColor(SPLASH_BACKGROUND_COLOR),
+            StateScoped(Screen::Splash),
+            SplashScreenContainer,
+        ));
+    }
 }
 
 #[derive(Component, Reflect)]
@@ -112,8 +176,35 @@ fn tick_splash_timer(time: Res<Time>, mut timer: ResMut<SplashTimer>) {
     timer.0.tick(time.delta());
 }
 
-fn check_splash_timer(timer: ResMut<SplashTimer>, mut next_screen: ResMut<NextState<Screen>>) {
-    if timer.0.just_finished() {
+fn check_splash_timer(
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    mut timer: ResMut<SplashTimer>,
+    mut next_screen: ResMut<NextState<Screen>>,
+    mut splash_screens: ResMut<SplashScreenImageList>,
+    containers: Query<Entity, With<SplashScreenContainer>>,
+) {
+    if !timer.0.just_finished() {
+        return;
+    }
+
+    // try to get  the next splash screen. If there isn't one, we move on to the next screen
+    if let Some(next_splash_image) = splash_screens.0.pop_front() {
+        // despawn other splash images
+        if let Ok(container) = containers.get_single() {
+            commands
+                .entity(container)
+                .despawn_descendants()
+                .with_children(|parent| {
+                    parent.spawn(splash_image_bundle(&asset_server, next_splash_image));
+                });
+        }
+
+        // reset the timer
+        timer.0.reset();
+    } else {
+        // no more splash screens, exit
         next_screen.set(Screen::Loading);
+        return;
     }
 }