src/game/java/net/minecraft/client/resources/sounds/ElytraOnPlayerSoundInstance.java

package net.minecraft.client.resources.sounds;

import net.minecraft.client.player.LocalPlayer;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.util.Mth;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class ElytraOnPlayerSoundInstance extends AbstractTickableSoundInstance {
    public static final int DELAY = 20;
    private final LocalPlayer player;
    private int time;

    public ElytraOnPlayerSoundInstance(LocalPlayer p_119673_) {
        super(SoundEvents.ELYTRA_FLYING, SoundSource.PLAYERS, SoundInstance.createUnseededRandom());
        this.player = p_119673_;
        this.looping = true;
        this.delay = 0;
        this.volume = 0.1F;
    }

    @Override
    public void tick() {
        this.time++;
        if (!this.player.isRemoved() && (this.time <= 20 || this.player.isFallFlying())) {
            this.x = (double)((float)this.player.getX());
            this.y = (double)((float)this.player.getY());
            this.z = (double)((float)this.player.getZ());
            float f = (float)this.player.getDeltaMovement().lengthSqr();
            if ((double)f >= 1.0E-7) {
                this.volume = Mth.clamp(f / 4.0F, 0.0F, 1.0F);
            } else {
                this.volume = 0.0F;
            }

            if (this.time < 20) {
                this.volume = 0.0F;
            } else if (this.time < 40) {
                this.volume = this.volume * ((float)(this.time - 20) / 20.0F);
            }

            float f1 = 0.8F;
            if (this.volume > 0.8F) {
                this.pitch = 1.0F + (this.volume - 0.8F);
            } else {
                this.pitch = 1.0F;
            }
        } else {
            this.stop();
        }
    }
}