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
+                }
+            }
+        }
+    }
+}