BloodAndGore/Assets/Scripts/Audio/MusicPlayer.cs

using UnityEngine;
using UnityEngine.SceneManagement;
using Saltosion.OneWeapon.Utils;

namespace Saltosion.OneWeapon.Audio {
    public enum MusicTrack {
        None = -1,
        Elevator = 0,
        SetFireToReality, // 1, and so on
        SpaceDimensions,
        ThrustSequence,
    }

    public enum AmbienceTrack {
        None = -1,
        Dark = 0,
    }

    enum Channel {
        Music, Ambience, Count
    }

    public class MusicPlayer : MonoBehaviour {
        private static MusicPlayer Singleton;
        private static int SingletonSceneIndex = -1;

        [Header("Audio files")]
        public AudioClip[] MusicClips;
        public AudioClip[] AmbienceClips;

        [Header("Other")]
        public MusicChannelPlayer ChannelPlayerForMusic;
        public MusicChannelPlayer ChannelPlayerForAmbience;
        public MusicTrack DebugMusicTrack = MusicTrack.None;
        public bool DebugSetMusicTrack = false;
        public AmbienceTrack DebugAmbienceTrack = AmbienceTrack.None;
        public bool DebugSetAmbienceTrack = false;

        private MusicChannelPlayer[] Channels;

        private void Start() {
            int Index = SceneManager.GetActiveScene().buildIndex;
            if (SingletonSceneIndex == Index) {
                Debug.LogWarning($"The scene '{SceneManager.GetActiveScene().name}' has multiple MusicPlayers!\nOnly the last to run Start() will be used.");
            }
            SingletonSceneIndex = Index;
            Singleton = this;

            Channels = new MusicChannelPlayer[(int)Channel.Count];
            Channels[(int)Channel.Music] = ChannelPlayerForMusic;
            Channels[(int)Channel.Ambience] = ChannelPlayerForAmbience;
        }

        private void Update() {
            ChannelPlayerForMusic.Volume = Options.MusicVolume;
            ChannelPlayerForAmbience.Volume = Options.AmbienceVolume;

            if (DebugSetMusicTrack) {
                DebugSetMusicTrack = false;
                SetMusicTrack(DebugMusicTrack, true);
            }
            if (DebugSetAmbienceTrack) {
                DebugSetAmbienceTrack = false;
                SetAmbienceTrack(DebugAmbienceTrack, true);
            }
        }

        private void SetChannelTrack(Channel channel, AudioClip clip, bool fade) {
            int channelIndex = (int)channel;
            if (Channels[channelIndex].CurrentlyPlaying) {
                Channels[channelIndex].FadingOut = fade;
            }
            if (clip != null) {
                Channels[channelIndex].FadingIn = fade;
                Channels[channelIndex].NextClip = clip;
            }
        }

        public static void SetMusicTrack(MusicTrack track, bool fade) {
            Singleton.SetChannelTrack(Channel.Music, track == MusicTrack.None ? null : Singleton.MusicClips[(int)track], fade);
        }

        public static void SetAmbienceTrack(AmbienceTrack track, bool fade) {
            Singleton.SetChannelTrack(Channel.Ambience, track == AmbienceTrack.None ? null : Singleton.AmbienceClips[(int)track], fade);
        }
    }
}