minecraft-src/net/minecraft/client/sounds/MusicManager.java

package net.minecraft.client.sounds;

import com.mojang.serialization.Codec;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.Minecraft;
import net.minecraft.client.resources.sounds.SimpleSoundInstance;
import net.minecraft.client.resources.sounds.Sound;
import net.minecraft.client.resources.sounds.SoundInstance;
import net.minecraft.sounds.Music;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.util.Mth;
import net.minecraft.util.OptionEnum;
import net.minecraft.util.RandomSource;
import net.minecraft.util.StringRepresentable;
import org.jetbrains.annotations.Nullable;

/**
 * The MusicManager class manages the playing of music in Minecraft.
 */
@Environment(EnvType.CLIENT)
public class MusicManager {
	/**
	 * The delay before starting to play the next song.
	 */
	private static final int STARTING_DELAY = 100;
	private final RandomSource random = RandomSource.create();
	private final Minecraft minecraft;
	@Nullable
	private SoundInstance currentMusic;
	private MusicManager.MusicFrequency gameMusicFrequency;
	private float currentGain = 1.0F;
	/**
	 * The delay until the next song starts.
	 */
	private int nextSongDelay = 100;
	private boolean toastShown = false;

	public MusicManager(Minecraft minecraft) {
		this.minecraft = minecraft;
		this.gameMusicFrequency = minecraft.options.musicFrequency().get();
	}

	/**
	 * Called every tick to manage the playing of music.
	 */
	public void tick() {
		MusicInfo musicInfo = this.minecraft.getSituationalMusic();
		float f = musicInfo.volume();
		if (this.currentMusic != null && this.currentGain != f) {
			boolean bl = this.fadePlaying(f);
			if (!bl) {
				return;
			}
		}

		Music music = musicInfo.music();
		if (music == null) {
			this.nextSongDelay = Math.max(this.nextSongDelay, 100);
		} else {
			if (this.currentMusic != null) {
				if (musicInfo.canReplace(this.currentMusic)) {
					this.minecraft.getSoundManager().stop(this.currentMusic);
					this.nextSongDelay = Mth.nextInt(this.random, 0, music.minDelay() / 2);
				}

				if (!this.minecraft.getSoundManager().isActive(this.currentMusic)) {
					this.currentMusic = null;
					this.nextSongDelay = Math.min(this.nextSongDelay, this.gameMusicFrequency.getNextSongDelay(music, this.random));
				}
			}

			this.nextSongDelay = Math.min(this.nextSongDelay, this.gameMusicFrequency.getNextSongDelay(music, this.random));
			if (this.currentMusic == null && this.nextSongDelay-- <= 0) {
				this.startPlaying(musicInfo);
			}
		}
	}

	public void startPlaying(MusicInfo music) {
		SoundEvent soundEvent = music.music().event().value();
		this.currentMusic = SimpleSoundInstance.forMusic(soundEvent, music.volume());
		switch (this.minecraft.getSoundManager().play(this.currentMusic)) {
			case STARTED:
				this.minecraft.getToastManager().showNowPlayingToast();
				this.toastShown = true;
				break;
			case STARTED_SILENTLY:
				this.toastShown = false;
		}

		this.nextSongDelay = Integer.MAX_VALUE;
		this.currentGain = music.volume();
	}

	public void showNowPlayingToastIfNeeded() {
		if (!this.toastShown) {
			this.minecraft.getToastManager().showNowPlayingToast();
			this.toastShown = true;
		}
	}

	/**
	 * Stops playing the specified {@linkplain Music} selector.
	 * 
	 * @param music the {@linkplain Music} selector to stop playing
	 */
	public void stopPlaying(Music music) {
		if (this.isPlayingMusic(music)) {
			this.stopPlaying();
		}
	}

	/**
	 * Stops playing the current {@linkplain Music} selector.
	 */
	public void stopPlaying() {
		if (this.currentMusic != null) {
			this.minecraft.getSoundManager().stop(this.currentMusic);
			this.currentMusic = null;
			this.minecraft.getToastManager().hideNowPlayingToast();
		}

		this.nextSongDelay += 100;
	}

	private boolean fadePlaying(float volume) {
		if (this.currentMusic == null) {
			return false;
		} else if (this.currentGain == volume) {
			return true;
		} else {
			if (this.currentGain < volume) {
				this.currentGain = this.currentGain + Mth.clamp(this.currentGain, 5.0E-4F, 0.005F);
				if (this.currentGain > volume) {
					this.currentGain = volume;
				}
			} else {
				this.currentGain = 0.03F * volume + 0.97F * this.currentGain;
				if (Math.abs(this.currentGain - volume) < 1.0E-4F || this.currentGain < volume) {
					this.currentGain = volume;
				}
			}

			this.currentGain = Mth.clamp(this.currentGain, 0.0F, 1.0F);
			if (this.currentGain <= 1.0E-4F) {
				this.stopPlaying();
				return false;
			} else {
				this.minecraft.getSoundManager().setVolume(this.currentMusic, this.currentGain);
				return true;
			}
		}
	}

	/**
	 * {@return {@code true} if the {@linkplain Music} selector is currently playing, {@code false} otherwise}
	 * 
	 * @param selector the {@linkplain Music} selector to check for
	 */
	public boolean isPlayingMusic(Music selector) {
		return this.currentMusic == null ? false : selector.event().value().location().equals(this.currentMusic.getLocation());
	}

	@Nullable
	public String getCurrentMusicTranslationKey() {
		if (this.currentMusic != null) {
			Sound sound = this.currentMusic.getSound();
			if (sound != null) {
				return sound.getLocation().toShortLanguageKey();
			}
		}

		return null;
	}

	public void setMinutesBetweenSongs(MusicManager.MusicFrequency musicFrequency) {
		this.gameMusicFrequency = musicFrequency;
		this.nextSongDelay = this.gameMusicFrequency.getNextSongDelay(this.minecraft.getSituationalMusic().music(), this.random);
	}

	@Environment(EnvType.CLIENT)
	public static enum MusicFrequency implements OptionEnum, StringRepresentable {
		DEFAULT(20),
		FREQUENT(10),
		CONSTANT(0);

		public static final Codec<MusicManager.MusicFrequency> CODEC = StringRepresentable.fromEnum(MusicManager.MusicFrequency::values);
		private static final String KEY_PREPEND = "options.music_frequency.";
		private final int id;
		private final int maxFrequency;
		private final String key;

		private MusicFrequency(final int maxFrequency) {
			this.id = maxFrequency;
			this.maxFrequency = maxFrequency * 1200;
			this.key = "options.music_frequency." + this.name().toLowerCase();
		}

		int getNextSongDelay(@Nullable Music music, RandomSource random) {
			if (music == null) {
				return this.maxFrequency;
			} else if (this == CONSTANT) {
				return 100;
			} else {
				int i = Math.min(music.minDelay(), this.maxFrequency);
				int j = Math.min(music.maxDelay(), this.maxFrequency);
				return Mth.nextInt(random, i, j);
			}
		}

		@Override
		public int getId() {
			return this.id;
		}

		@Override
		public String getKey() {
			return this.key;
		}

		@Override
		public String getSerializedName() {
			return this.name();
		}
	}
}