Fixes for pegasus flying wind sound effect

This fixes several aspects of the wind sound effect:
-Interpolation of FadeOutSoundInstance breaking the effect's volume controls
-Attenuation and panning (3D audio) should now work correctly for other clients
-New attenuation curve for velocity based attenuation
-New pitch controls same as above
-Made effect a continuous loop
-Added rate limiter so that sudden movements won't cause volume and pitch jolts (storms?)

src/main/java/com/minelittlepony/unicopia/USounds.java

@@ -10,6 +10,7 @@ public interface USounds {
     SoundEvent ENTITY_PLAYER_BATPONY_SCREECH = register("entity.player.batpony.screech");
     SoundEvent ENTITY_PLAYER_REBOUND = register("entity.player.rebound");
     SoundEvent ENTITY_PLAYER_PEGASUS_WINGSFLAP = register("entity.player.pegasus.wingsflap");
+    SoundEvent ENTITY_PLAYER_PEGASUS_FLYING = register("entity.player.pegasus.flying");
     SoundEvent ENTITY_PLAYER_PEGASUS_DASH = register("entity.player.pegasus.dash");
     SoundEvent ENTITY_PLAYER_PEGASUS_MOLT = register("entity.player.pegasus.molt");
     SoundEvent ENTITY_PLAYER_CHANGELING_BUZZ = register("entity.player.changeling.buzz");

src/main/java/com/minelittlepony/unicopia/client/ClientInteractionManager.java

@@ -75,8 +75,10 @@ public class ClientInteractionManager extends InteractionManager {
                     PlayerPhysics physics = Pony.of(e).getPhysics();
                     return physics.isFlying() && physics.getFlightType() == FlightType.INSECTOID;
                 }, USounds.ENTITY_PLAYER_CHANGELING_BUZZ, 1F, 1F, Random.create(seed)));
-            } else if (type == SOUND_GLIDING && source instanceof PlayerEntity) {
+            } else if (type == SOUND_GLIDING && source instanceof PlayerEntity && isClientPlayer((PlayerEntity) source)) {
                 soundManager.play(new MotionBasedSoundInstance(SoundEvents.ITEM_ELYTRA_FLYING, (PlayerEntity)source, Random.create(seed)));
+            } else if (type == SOUND_GLIDING && source instanceof PlayerEntity) {
+                soundManager.play(new MotionBasedSoundInstance(USounds.ENTITY_PLAYER_PEGASUS_FLYING, (PlayerEntity)source, Random.create(seed)));
             } else if (type == SOUND_MAGIC_BEAM) {
                 soundManager.play(new LoopedEntityTrackingSoundInstance(USounds.SPELL_CAST_SHOOT, 0.3F, 1F, source, seed));
             }

src/main/java/com/minelittlepony/unicopia/client/sound/FadeOutSoundInstance.java

@@ -81,6 +81,12 @@ public abstract class FadeOutSoundInstance extends MovingSoundInstance {
         progress = 0;
     }
 
+    protected void setVolume(float vol){
+        sourceVolume = vol;
+        targetVolume = vol;
+        progress = 0;
+    }
+
     private float getLerpedVolume() {
         float delta = MinecraftClient.getInstance().getTickDelta();
         float interpolate = MathHelper.clamp(MathHelper.lerp(delta, prevProgress, progress) / transitionTicks, 0, 1);

src/main/java/com/minelittlepony/unicopia/client/sound/MotionBasedSoundInstance.java

@@ -2,6 +2,7 @@ package com.minelittlepony.unicopia.client.sound;
 
 import com.minelittlepony.unicopia.entity.player.Pony;
 
+import net.minecraft.client.MinecraftClient;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.sound.SoundEvent;
 import net.minecraft.util.math.MathHelper;
@@ -11,18 +12,30 @@ public class MotionBasedSoundInstance extends FadeOutSoundInstance {
 
     private final PlayerEntity player;
 
+    // Tune these if you want to change the way this sounds!
+    // Currently just hardcoded for flying because nothing else uses this class
+    private static final float MAX_VELOCITY = 1.5f;    // Max velocity before we clamp volume (units/tick?)
+    private static final float VOLUME_AT_MAX = 1.0f;
+    private static final float ATTEN_EXPO = 2.0f;       // Exponent for velocity based attenuation
+    private static final int FADEIN_TICKS = 20;         // Ticks for fade-in
+    private static final float MIN_PITCH = 0.7f;        // Pitch at 0-speed
+    private static final float MAX_PITCH = 2.6f;        // Pitch at reference speed MAX_VELOCITY
+    private static final float MAX_RATE_TICKS = 20.0f;       // How many ticks it takes to go from 0 to max volume (filter!)
+
     private int tickCount;
+    private float currentVal;   // Cache last tick's curve value
 
     public MotionBasedSoundInstance(SoundEvent sound, PlayerEntity player, Random random) {
         super(sound, player.getSoundCategory(), 0.1F, random);
         this.player = player;
+        currentVal = 0.0f;
     }
 
     @Override
     protected boolean shouldKeepPlaying() {
         ++tickCount;
 
-        if (player.isRemoved() || tickCount > 200) {
+        if (player.isRemoved()) {
             return false;
         }
 
@@ -32,30 +45,41 @@ public class MotionBasedSoundInstance extends FadeOutSoundInstance {
             return false;
         }
 
+        // Update effect position
         x = ((float)player.getX());
         y = ((float)player.getY());
-        z = ((float)this.player.getZ());
+        z = ((float)player.getZ());
 
+        // Get velocity
         float f = (float)player.getVelocity().horizontalLength();
+
+        float lastVal = currentVal;
+
+        // First we normalise the volume to the maximum velocity we're targeting, then we make it a curve.
+        // Drag is not linear, and neither is the woosh it produces, so a curve makes it sound more natural.
+        currentVal = (float) Math.pow(MathHelper.clamp(f / MAX_VELOCITY, 0, 1),ATTEN_EXPO);
+
+        // Primitive lowpass filter/rate limiter thingy to rule out sudden jolts
+        currentVal = lastVal + MathHelper.clamp(currentVal - lastVal, -(1/MAX_RATE_TICKS), 1/MAX_RATE_TICKS);
+
         if (f >= 1.0E-7D) {
-           volume = MathHelper.clamp(f / 4F, 0, 1);
+           // Multiply output volume by reference volume for overall gain control.
+           volume = currentVal * VOLUME_AT_MAX;
         } else {
            volume = 0.0F;
         }
 
-        if (tickCount < 20) {
+        // If we only just started playing, fade in!
-           volume = 0;
+        if (tickCount < FADEIN_TICKS) {
-        } else if (tickCount < 40) {
+           volume *= ((tickCount) / (float)FADEIN_TICKS);
-           volume = (float)(volume * ((tickCount - 20) / 20D));
         }
 
-        if (volume > 0.8F) {
+        // Control pitch with velocity
-           pitch = 1 + (volume - 0.8F);
+        pitch = MathHelper.lerp(currentVal,MIN_PITCH,MAX_PITCH);
-        } else {
-           pitch = 1;
-        }
 
-        setTargetVolume(volume);
+        // Setting target volume every frame breaks interpolation. We set volume directly,
+        // so that FadeOutSoundInstance only handles stopping the sound with an actual fade out!
+        setVolume(volume);
 
         return true;
     }

src/main/resources/assets/unicopia/sounds.json

@@ -21,6 +21,14 @@
       "unicopia:woosh/woosh5"
     ]
   },
+  "entity.player.pegasus.flying": {
+    "sounds": [
+      {
+        "name": "unicopia:wind/flying_loop",
+        "volume": 0.6
+      }
+    ]
+  },
   "item.magic.aura": {
     "category": "player",
     "subtitle": "unicopia.subtitle.magic_aura",