it is done

core/src/mindustry/game/LoopControl.java

@@ -0,0 +1,61 @@
+package mindustry.game;
+
+import arc.*;
+import arc.audio.*;
+import arc.struct.*;
+import arc.math.*;
+import arc.math.geom.*;
+import mindustry.*;
+
+public class LoopControl{
+    private ObjectMap<Sound, SoundData> sounds = new ObjectMap<>();
+
+    public void play(Sound sound, Position pos, float volume){
+        if(Vars.headless) return;
+
+        float baseVol = sound.calcFalloff(pos.getX(), pos.getY());
+        float vol = baseVol * volume;
+
+        SoundData data = sounds.getOr(sound, SoundData::new);
+        data.volume += vol;
+        data.volume = Mathf.clamp(data.volume, 0f, 1f);
+        data.total += baseVol;
+        data.sum.add(pos.getX() * baseVol, pos.getY() * baseVol);
+    }
+
+    public void update(){
+        float avol = Core.settings.getInt("ambientvol", 100) / 100f;
+
+        sounds.each((sound, data) -> {
+            data.curVolume = Mathf.lerpDelta(data.curVolume, data.volume * avol, 0.2f);
+
+            boolean play = data.curVolume > 0.01f;
+            float pan = Mathf.zero(data.total, 0.0001f) ? 0f : sound.calcPan(data.sum.x / data.total, data.sum.y / data.total);
+            if(data.soundID <= 0){
+                if(play){
+                    data.soundID = sound.loop(data.curVolume, 1f, pan);
+                }
+            }else{
+                if(data.curVolume <= 0.01f){
+                    sound.stop();
+                    data.soundID = -1;
+                    return;
+                }
+                sound.setPan(data.soundID, pan, data.curVolume);
+            }
+
+            data.volume = 0f;
+            data.total = 0f;
+            data.sum.setZero();
+        });
+    }
+
+    private class SoundData{
+        float volume;
+        float total;
+        Vector2 sum = new Vector2();
+
+        int soundID;
+        float curVolume;
+    }
+}