Ambient sound system (#4552)

* Ambient sound system

Client-side system that plays audio from nearby objects that are randomly sampled.

* Decent

* Tweaks

* Tweaks

* Comment this out for now

* reduce VM sound

* Fix rolloff

* Fixes

* Volume tweak

Content.Client/Audio/AmbientSoundSystem.cs

@@ -0,0 +1,178 @@
+using System.Collections.Generic;
+using System.Linq;
+using Content.Shared.Audio;
+using Content.Shared.CCVar;
+using Robust.Client.Player;
+using Robust.Shared.Audio;
+using Robust.Shared.Configuration;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Player;
+using Robust.Shared.Random;
+
+namespace Content.Client.Audio
+{
+    /// <summary>
+    /// Samples nearby <see cref="AmbientSoundComponent"/> and plays audio.
+    /// </summary>
+    public sealed class AmbientSoundSystem : SharedAmbientSoundSystem
+    {
+        [Dependency] private IEntityLookup _lookup = default!;
+        [Dependency] private readonly IPlayerManager _playerManager = default!;
+        [Dependency] private readonly IRobustRandom _random = default!;
+
+        private int _maxAmbientCount;
+
+        private float _maxAmbientRange;
+        private float _cooldown;
+        private float _accumulator;
+
+        /// <summary>
+        /// How many times we can be playing 1 particular sound at once.
+        /// </summary>
+        private int _maxSingleSound = 3;
+
+        private Dictionary<AmbientSoundComponent, (IPlayingAudioStream? Stream, string Sound)> _playingSounds = new();
+
+        private const float RangeBuffer = 0.5f;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            var configManager = IoCManager.Resolve<IConfigurationManager>();
+            configManager.OnValueChanged(CCVars.AmbientCooldown, SetCooldown, true);
+            configManager.OnValueChanged(CCVars.MaxAmbientSources, SetAmbientCount, true);
+            configManager.OnValueChanged(CCVars.AmbientRange, SetAmbientRange, true);
+        }
+
+        private void SetCooldown(float value) => _cooldown = value;
+        private void SetAmbientCount(int value) => _maxAmbientCount = value;
+        private void SetAmbientRange(float value) => _maxAmbientRange = value;
+
+        public override void Shutdown()
+        {
+            base.Shutdown();
+            var configManager = IoCManager.Resolve<IConfigurationManager>();
+            configManager.UnsubValueChanged(CCVars.AmbientCooldown, SetCooldown);
+            configManager.UnsubValueChanged(CCVars.MaxAmbientSources, SetAmbientCount);
+            configManager.UnsubValueChanged(CCVars.AmbientRange, SetAmbientRange);
+        }
+
+        private int PlayingCount(string countSound)
+        {
+            var count = 0;
+
+            foreach (var (_, (_, sound)) in _playingSounds)
+            {
+                if (sound.Equals(countSound)) count++;
+            }
+
+            return count;
+        }
+
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+
+            if (_cooldown <= 0f)
+            {
+                _accumulator = 0f;
+                return;
+            }
+
+            _accumulator += frameTime;
+            if (_accumulator < _cooldown) return;
+            _accumulator -= _cooldown;
+
+            var player = _playerManager.LocalPlayer?.ControlledEntity;
+            if (player == null)
+            {
+                ClearSounds();
+                return;
+            }
+
+            var coordinates = player.Transform.Coordinates;
+
+            foreach (var (comp, (stream, _)) in _playingSounds.ToArray())
+            {
+                if (!comp.Deleted && comp.Enabled && comp.Owner.Transform.Coordinates.TryDistance(EntityManager, coordinates, out var range) &&
+                    range <= comp.Range)
+                {
+                    continue;
+                }
+
+                stream?.Stop();
+
+                _playingSounds.Remove(comp);
+            }
+
+            if (_playingSounds.Count >= _maxAmbientCount) return;
+
+            SampleNearby(coordinates);
+        }
+
+        private void ClearSounds()
+        {
+            foreach (var (_, (stream, _)) in _playingSounds)
+            {
+                stream?.Stop();
+            }
+
+            _playingSounds.Clear();
+        }
+
+        /// <summary>
+        /// Get a list of ambient components in range and determine which ones to start playing.
+        /// </summary>
+        private void SampleNearby(EntityCoordinates coordinates)
+        {
+            var compsInRange = new List<AmbientSoundComponent>();
+
+            foreach (var entity in _lookup.GetEntitiesInRange(coordinates, _maxAmbientRange,
+                LookupFlags.Approximate | LookupFlags.IncludeAnchored))
+            {
+                if (!entity.TryGetComponent(out AmbientSoundComponent? ambientComp) ||
+                    _playingSounds.ContainsKey(ambientComp) ||
+                    !ambientComp.Enabled ||
+                    // We'll also do this crude distance check because it's what we're doing in the active loop above.
+                    !entity.Transform.Coordinates.TryDistance(EntityManager, coordinates, out var range) ||
+                    range > ambientComp.Range - RangeBuffer)
+                {
+                    continue;
+                }
+
+                compsInRange.Add(ambientComp);
+            }
+
+            while (_playingSounds.Count < _maxAmbientCount)
+            {
+                if (compsInRange.Count == 0) break;
+
+                var comp = _random.PickAndTake(compsInRange);
+                var sound = comp.Sound.GetSound();
+
+                if (PlayingCount(sound) >= _maxSingleSound) continue;
+
+                var audioParams = AudioHelpers
+                    .WithVariation(0.01f)
+                    .WithVolume(comp.Volume)
+                    .WithLoop(true)
+                    .WithAttenuation(Attenuation.LinearDistance)
+                    // Randomise start so 2 sources don't increase their volume.
+                    .WithPlayOffset(_random.NextFloat())
+                    .WithMaxDistance(comp.Range);
+
+                var stream = SoundSystem.Play(
+                    Filter.Local(),
+                    sound,
+                    comp.Owner,
+                    audioParams);
+
+                if (stream == null) continue;
+
+                _playingSounds[comp] = (stream, sound);
+            }
+        }
+    }
+}