Clamp audio tickrate (#5296)

* Clamp audio tickrate

I am reasonably sure I saw a recommended 30TPS figure somewhere but I cannot find it again. At any rate I can't notice this but imagine it provides significant benefits for people on 144hz+ monitors.

* rn

---------

Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

RELEASE-NOTES.md

@@ -39,7 +39,7 @@ END TEMPLATE-->
 
 ### New features
 
-*None yet*
+* Audio ticks-per-second is now capped at 30 by default and controlled via `audio.tick_rate` cvar.
 
 ### Bugfixes
 

Robust.Client/Audio/AudioSystem.cs

@@ -37,7 +37,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
     [Dependency] private readonly IReplayRecordingManager _replayRecording = default!;
     [Dependency] private readonly IEyeManager _eyeManager = default!;
     [Dependency] private readonly IResourceCache _resourceCache = default!;
-    [Dependency] private readonly IMapManager _mapManager = default!;
     [Dependency] private readonly IParallelManager _parMan = default!;
     [Dependency] private readonly IRuntimeLog _runtimeLog = default!;
     [Dependency] private readonly IAudioInternal _audio = default!;
@@ -49,9 +48,10 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// Per-tick cache of relevant streams.
     /// </summary>
     private readonly List<(EntityUid Entity, AudioComponent Component, TransformComponent Xform)> _streams = new();
-    private EntityUid? _listenerGrid;
     private UpdateAudioJob _updateAudioJob;
 
+    private float _audioFrameTime;
+    private float _audioFrameTimeRemaining;
 
     private EntityQuery<PhysicsComponent> _physicsQuery;
 
@@ -110,9 +110,16 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
         Subs.CVar(CfgManager, CVars.AudioAttenuation, OnAudioAttenuation, true);
         Subs.CVar(CfgManager, CVars.AudioRaycastLength, OnRaycastLengthChanged, true);
+        Subs.CVar(CfgManager, CVars.AudioTickRate, OnAudioTickRate, true);
         InitializeLimit();
     }
 
+    private void OnAudioTickRate(int obj)
+    {
+        _audioFrameTime = 1f / obj;
+        _audioFrameTimeRemaining = MathF.Min(_audioFrameTimeRemaining, _audioFrameTime);
+    }
+
     private void OnAudioState(EntityUid uid, AudioComponent component, ref AfterAutoHandleStateEvent args)
     {
         ApplyAudioParams(component.Params, component);
@@ -254,6 +261,13 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
     public override void FrameUpdate(float frameTime)
     {
+        _audioFrameTimeRemaining -= frameTime;
+
+        if (_audioFrameTimeRemaining > 0f)
+            return;
+
+        // Clamp to 0 in case we have a really long frame.
+        _audioFrameTimeRemaining = MathF.Max(0f, _audioFrameTime + _audioFrameTimeRemaining);
         var eye = _eyeManager.CurrentEye;
         var localEntity = _playerManager.LocalEntity;
         Vector2 listenerVelocity;
@@ -277,9 +291,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
             _streams.Add((uid, comp, xform));
         }
 
-        _mapManager.TryFindGridAt(ourPos, out var gridUid, out _);
-        _listenerGrid = gridUid == EntityUid.Invalid ? null : gridUid;
-
         try
         {
             _updateAudioJob.OurPosition = ourPos;
@@ -332,7 +343,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
         Vector2 worldPos;
         component.Volume = component.Params.Volume;
-        Vector2 delta;
 
         // Handle grid audio differently by using grid position.
         if ((component.Flags & AudioFlags.GridAudio) != 0x0)
@@ -346,7 +356,7 @@ public sealed partial class AudioSystem : SharedAudioSystem
         }
 
         // Max distance check
-        delta = worldPos - listener.Position;
+        var delta = worldPos - listener.Position;
         var distance = delta.Length();
 
         // Out of range so just clip it for us.

Robust.Shared/CVars.cs

@@ -1157,6 +1157,13 @@ namespace Robust.Shared
         public static readonly CVarDef<float> AudioRaycastLength =
             CVarDef.Create("audio.raycast_length", SharedAudioSystem.DefaultSoundRange, CVar.ARCHIVE | CVar.CLIENTONLY);
 
+        /// <summary>
+        /// Tickrate for audio calculations.
+        /// OpenAL recommends 30TPS. This is to avoid running raycasts every frame especially for high-refresh rate monitors.
+        /// </summary>
+        public static readonly CVarDef<int> AudioTickRate =
+            CVarDef.Create("audio.tick_rate", 30, CVar.CLIENTONLY);
+
         public static readonly CVarDef<float> AudioZOffset =
             CVarDef.Create("audio.z_offset", -5f, CVar.REPLICATED);