feat: ecs audio system

src/systems/audio.rs

@@ -0,0 +1,54 @@
+//! Audio system for handling sound playback in the Pac-Man game.
+//!
+//! This module provides an ECS-based audio system that integrates with SDL2_mixer
+//! for playing sound effects. The system uses NonSendMut resources to handle SDL2's
+//! main-thread requirements while maintaining Bevy ECS compatibility.
+
+use bevy_ecs::{
+    event::{Event, EventReader, EventWriter},
+    system::{NonSendMut, ResMut},
+};
+
+use crate::{audio::Audio, error::GameError, systems::components::AudioState};
+
+/// Events for triggering audio playback
+#[derive(Event, Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AudioEvent {
+    /// Play the "eat" sound when Pac-Man consumes a pellet
+    PlayEat,
+}
+
+/// Non-send resource wrapper for SDL2 audio system
+///
+/// This wrapper is needed because SDL2 audio components are not Send,
+/// but Bevy ECS requires Send for regular resources. Using NonSendMut
+/// allows us to use SDL2 audio on the main thread while integrating
+/// with the ECS system.
+pub struct AudioResource(pub Audio);
+
+/// System that processes audio events and plays sounds
+pub fn audio_system(
+    mut audio: NonSendMut<AudioResource>,
+    mut audio_state: ResMut<AudioState>,
+    mut audio_events: EventReader<AudioEvent>,
+    _errors: EventWriter<GameError>,
+) {
+    // Set mute state if it has changed
+    if audio.0.is_muted() != audio_state.muted {
+        audio.0.set_mute(audio_state.muted);
+    }
+
+    // Process audio events
+    for event in audio_events.read() {
+        match event {
+            AudioEvent::PlayEat => {
+                if !audio.0.is_disabled() && !audio_state.muted {
+                    audio.0.eat();
+                    // Update the sound index for cycling through sounds
+                    audio_state.sound_index = (audio_state.sound_index + 1) % 4;
+                    // 4 eat sounds available
+                }
+            }
+        }
+    }
+}

src/systems/components.rs

@@ -107,3 +107,12 @@ pub struct DeltaTime(pub f32);
 
 #[derive(Resource, Default)]
 pub struct RenderDirty(pub bool);
+
+/// Resource for tracking audio state
+#[derive(Resource, Debug, Clone, Default)]
+pub struct AudioState {
+    /// Whether audio is currently muted
+    pub muted: bool,
+    /// Current sound index for cycling through eat sounds
+    pub sound_index: usize,
+}

src/systems/item.rs

@@ -2,7 +2,10 @@ use bevy_ecs::{event::EventReader, prelude::*, query::With, system::Query};
 
 use crate::{
     events::GameEvent,
-    systems::components::{EntityType, ItemCollider, PacmanCollider, ScoreResource},
+    systems::{
+        audio::AudioEvent,
+        components::{EntityType, ItemCollider, PacmanCollider, ScoreResource},
+    },
 };
 
 pub fn item_system(
@@ -11,6 +14,7 @@ pub fn item_system(
     mut score: ResMut<ScoreResource>,
     pacman_query: Query<Entity, With<PacmanCollider>>,
     item_query: Query<(Entity, &EntityType), With<ItemCollider>>,
+    mut events: EventWriter<AudioEvent>,
 ) {
     for event in collision_events.read() {
         if let GameEvent::Collision(entity1, entity2) = event {
@@ -37,6 +41,8 @@ pub fn item_system(
 
                 // Remove the collected item
                 commands.entity(item_ent).despawn();
+
+                events.write(AudioEvent::PlayEat);
             }
         }
     }

src/systems/mod.rs

@@ -3,6 +3,7 @@
 //! This module contains all the ECS-related logic, including components, systems,
 //! and resources.
 
+pub mod audio;
 pub mod blinking;
 pub mod collision;
 pub mod components;

src/systems/profiling.rs

@@ -7,7 +7,7 @@ use std::time::Duration;
 use thousands::Separable;
 
 /// The maximum number of systems that can be profiled. Must not be exceeded, or it will panic.
-const MAX_SYSTEMS: usize = 11;
+const MAX_SYSTEMS: usize = 12;
 /// The number of durations to keep in the circular buffer.
 const TIMING_WINDOW_SIZE: usize = 30;