add a cozy fade-in from black on start

src/effects.rs

@@ -0,0 +1,92 @@
+use bevy::prelude::*;
+use crate::settings;
+
+pub struct EffectsPlugin;
+
+impl Plugin for EffectsPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, setup);
+        app.add_systems(Startup, spawn_effects.after(setup));
+        app.add_systems(Update, spawn_effects);
+        app.add_systems(Update, update_fadeblack);
+        app.add_event::<SpawnEffectEvent>();
+    }
+}
+
+#[derive(Clone)]
+pub enum Effects {
+    FadeIn,
+}
+
+#[derive(Component)] pub struct FadeBlack;
+#[derive(Component)]
+pub struct Effect {
+    pub class: Effects,
+    pub duration: f64,
+    pub start_time: f64,
+}
+#[derive(Event)]
+pub struct SpawnEffectEvent {
+    pub class: Effects,
+    pub duration: f64,
+}
+
+pub fn setup(
+    settings: Res<settings::Settings>,
+    mut ew_effect: EventWriter<SpawnEffectEvent>,
+) {
+    if !settings.dev_mode {
+        ew_effect.send(SpawnEffectEvent { class: Effects::FadeIn, duration: 4.0 });
+    }
+}
+
+pub fn spawn_effects(
+    mut commands: Commands,
+    mut er_effect: EventReader<SpawnEffectEvent>,
+    time: Res<Time>,
+) {
+    let now = time.elapsed_seconds_f64();
+    for effect in er_effect.read() {
+        match effect.class {
+            Effects::FadeIn => {
+                commands.spawn((
+                    Effect {
+                        class: effect.class.clone(),
+                        duration: effect.duration,
+                        start_time: now,
+                    },
+                    FadeBlack,
+                    NodeBundle {
+                        style: Style {
+                            width: Val::Vw(100.0),
+                            height: Val::Vh(100.0),
+                            position_type: PositionType::Absolute,
+                            top: Val::Px(0.0),
+                            left: Val::Px(0.0),
+                            ..default()
+                        },
+                        background_color: Color::rgba(0.0, 0.0, 0.0, 1.0).into(),
+                        ..default()
+                    },
+                ));
+            },
+            //_ => {},
+        }
+    }
+}
+
+pub fn update_fadeblack(
+    mut commands: Commands,
+    mut q_effect: Query<(Entity, &Effect, &mut BackgroundColor), With<FadeBlack>>,
+    time: Res<Time>,
+) {
+    for (entity, effect, mut bgcolor) in &mut q_effect {
+        let now = time.elapsed_seconds_f64();
+        if effect.start_time + effect.duration < now {
+            commands.entity(entity).despawn();
+            continue;
+        }
+        let alpha = (1.3 - 1.3 * (now - effect.start_time) / effect.duration).clamp(0.0, 1.0);
+        bgcolor.0 = Color::rgba(0.0, 0.0, 0.0, alpha as f32);
+    }
+}

src/main.rs

@@ -4,6 +4,7 @@ mod world;
 mod settings;
 mod hud;
 mod actor;
+mod effects;
 
 #[allow(dead_code)]
 mod nature;
@@ -53,6 +54,7 @@ impl Plugin for OutFlyPlugin {
             hud::HudPlugin,
             actor::ActorPlugin,
             audio::AudioPlugin,
+            effects::EffectsPlugin,
         ));
     }
 }

src/settings.rs

@@ -3,6 +3,7 @@ use std::env;
 
 #[derive(Resource)]
 pub struct Settings {
+    pub dev_mode: bool,
     pub mute_sfx: bool,
     pub mute_music: bool,
     pub volume_sfx: u8,
@@ -48,17 +49,24 @@ pub struct Settings {
 
 impl Default for Settings {
     fn default() -> Self {
+        let dev_mode;
+
         let default_mute_sfx = false;
         let default_mute_music;
         if let Ok(_) = env::var("CARGO") {
             // Mute audio by default when run through `cargo`
             default_mute_music = cfg!(debug_assertions);
+
+            // Enable dev mode when running `cargo run` without `--release`
+            dev_mode = cfg!(debug_assertions);
         }
         else {
             default_mute_music = false;
+            dev_mode = false;
         }
 
         Settings {
+            dev_mode: dev_mode,
             mute_sfx: default_mute_sfx,
             mute_music: default_mute_music,
             volume_sfx: 100,