riversong code showcase

Source/Riversong/Game/Audio/BackgroundMusicSystem.cs

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+using System;
+using Cysharp.Threading.Tasks;
+using PrimeTween;
+using UnityEngine;
+
+namespace DanieleMarotta.RiversongCodeShowcase
+{
+    [GameSystemGroup(typeof(AudioSystemGroup))]
+    public class BackgroundMusicSystem : GameSystem, IInitializable, IDisposable
+    {
+        [InjectService]
+        private GameConfig _config;
+
+        [InjectService]
+        private IScene _scene;
+
+        [InjectService]
+        private ISignalBus _signalBus;
+
+        private AudioSource _audioSource;
+
+        private AudioClip _mainThemeClip;
+
+        private AudioClip _gameplayClip;
+
+        public BackgroundMusicSystem(IServiceLocator serviceLocator) : base(serviceLocator)
+        {
+        }
+
+        public async UniTask InitializeAsync()
+        {
+            _audioSource = new GameObject("BGM").AddComponent<AudioSource>();
+            _audioSource.transform.SetParent(_scene.SceneFolders.AudioSources);
+            _audioSource.playOnAwake = false;
+            _audioSource.loop = true;
+
+            _mainThemeClip = await _config.Audio.MainThemeClip.LoadAssetAsync<AudioClip>();
+            _gameplayClip = await _config.Audio.GameplayClip.LoadAssetAsync<AudioClip>();
+
+            _signalBus.Subscribe<GameInitializationCompletedSignal>(OnGameInitializationCompleted);
+            _signalBus.Subscribe<GameStartedSignal>(OnGameStarted);
+            _signalBus.Subscribe<WorldReadySignal>(OnWorldReady);
+        }
+
+        public void Dispose()
+        {
+            _signalBus.Unsubscribe<GameInitializationCompletedSignal>(OnGameInitializationCompleted);
+            _signalBus.Unsubscribe<GameStartedSignal>(OnGameStarted);
+            _signalBus.Unsubscribe<WorldReadySignal>(OnWorldReady);
+        }
+
+        private void OnGameInitializationCompleted(GameInitializationCompletedSignal signal)
+        {
+            Play(_mainThemeClip, _config.Audio.MainThemeVolume);
+        }
+
+        private void OnGameStarted(GameStartedSignal signal)
+        {
+            _ = FadeOutAsync(2);
+        }
+
+        private async UniTask FadeOutAsync(float duration)
+        {
+            await Tween.Custom(_audioSource.volume, 0, duration, value => _audioSource.volume = value, Ease.Linear);
+        }
+
+        private void OnWorldReady(WorldReadySignal signal)
+        {
+            Play(_gameplayClip, _config.Audio.GameplayVolume);
+        }
+
+        private void Play(AudioClip clip, float volume)
+        {
+            _audioSource.Stop();
+
+            _audioSource.clip = clip;
+            _audioSource.volume = volume;
+
+            _audioSource.Play();
+        }
+    }
+}