fungus/Assets/Fungus/Audio/Scripts/MusicController.cs

using UnityEngine;
using System.Collections;

namespace Fungus
{
	/**
	 * Singleton music manager component.
	 * Provides basic music and sound effect functionality.
	 * Music playback persists across scene loads.
	 */
	[RequireComponent(typeof(AudioSource))]
	public class MusicController : MonoBehaviour 
	{
		static MusicController instance;

		/**
		 * Returns the MusicController singleton instance.
		 * Will create a MusicController game object if none currently exists.
		 */
		static public MusicController GetInstance()
		{
			if (instance == null)
			{
				GameObject go = new GameObject("MusicController");
				DontDestroyOnLoad(go);
				instance = go.AddComponent<MusicController>();
			}

			return instance;
		}

		protected virtual void Start()
		{
			GetComponent<AudioSource>().playOnAwake = false;
			GetComponent<AudioSource>().loop = true;
		}

		/**
		 * Plays game music using an audio clip.
		 * One music clip may be played at a time.
		 * @param musicClip The music clip to play
		 * @param atTime Time in the music clip to start at
		 */
		public void PlayMusic(AudioClip musicClip, bool loop, float fadeDuration, float atTime)
		{
			AudioSource audioSource = GetComponent<AudioSource>();
			if (audioSource == null || audioSource.clip == musicClip)
			{
				return;
			}

			if (fadeDuration == 0f)
			{
				audioSource.clip = musicClip;
				audioSource.loop = loop;
				audioSource.time = atTime;	// May be inaccurate if the audio source is compressed http://docs.unity3d.com/ScriptReference/AudioSource-time.html BK
				audioSource.Play();
			}
			else
			{
				float startVolume = audioSource.volume;

				LeanTween.value(gameObject, startVolume, 0f, fadeDuration)
					.setOnUpdate( (v) => {
						// Fade out current music
						audioSource.volume = v;
					}).setOnComplete( () => {
						// Play new music
						audioSource.volume = startVolume;
						audioSource.clip = musicClip;
						audioSource.loop = loop;
						audioSource.time = atTime;	// May be inaccurate if the audio source is compressed http://docs.unity3d.com/ScriptReference/AudioSource-time.html BK
						audioSource.Play();
					});
			}
		}

		/**
		 * Stops playing game music.
		 */
		public virtual void StopMusic()
		{
			GetComponent<AudioSource>().Stop();
		}

		/**
		 * Fades the game music volume to required level over a period of time.
		 * @param volume The new music volume value [0..1]
		 * @param duration The length of time in seconds needed to complete the volume change.
		 */
		public virtual void SetAudioVolume(float volume, float duration)
		{
			AudioSource audio = GetComponent<AudioSource>();

			if (duration == 0f)
			{
				audio.volume = volume;
				return;
			}

			LeanTween.value(gameObject, 
				audio.volume, 
				volume, 
				duration).setOnUpdate( (v) => {
					audio.volume = v;
				});
		}

		/**
		 * Shifts the game music pitch to required value over a period of time.
		 * @param volume The new music pitch value
		 * @param duration The length of time in seconds needed to complete the pitch change.
		 * @param onComplete A delegate method to call when the pitch shift has completed.
		 */
		public virtual void SetAudioPitch(float pitch, float duration, System.Action onComplete)
		{
			AudioSource audio = GetComponent<AudioSource>();

			if (duration == 0f)
			{
				audio.pitch = pitch;
				if (onComplete != null)
				{
					onComplete();
				}
				return;
			}

			LeanTween.value(gameObject, 
				audio.pitch, 
				pitch, 
				duration).setOnUpdate( (p) => {
					audio.pitch = p;
				}).setOnComplete( () => {
					if (onComplete != null)
					{
						onComplete();
					}
				});
		}

		/**
		 * Plays a sound effect once, at the specified volume.
		 * Multiple sound effects can be played at the same time.
		 * @param soundClip The sound effect clip to play
		 * @param volume The volume level of the sound effect
		 */
		public virtual void PlaySound(AudioClip soundClip, float volume)
		{
			GetComponent<AudioSource>().PlayOneShot(soundClip, volume);
		}

		public virtual void PlaySoundAtTime(AudioClip soundClip, float volume, float atTime)
		{
			GetComponent<AudioSource>().time = atTime;						// This may not work BK
			GetComponent<AudioSource>().PlayOneShot(soundClip, volume);
		}
	}
}