Remove ICollideSpecial entirely (#1782)

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

Robust.Client.NameGenerator/XamlUiPartialClassGenerator.cs

@@ -247,7 +247,6 @@ namespace {nameSpace}
                                 DiagnosticSeverity.Error,
                                 true),
                             Location.None));
-                    return null;
                 }
             }
 

Robust.Client/Audio/Midi/MidiManager.cs

@@ -6,14 +6,18 @@ using System.Threading;
 using NFluidsynth;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
+using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
+using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 using Robust.Shared.Physics.Broadphase;
 using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 using Logger = Robust.Shared.Log.Logger;
 
 namespace Robust.Client.Audio.Midi
@@ -32,24 +36,6 @@ namespace Robust.Client.Audio.Midi
         /// </returns>
         IMidiRenderer? GetNewRenderer();
 
-        /*
-        /// <summary>
-        ///     Checks whether the file at the given path is a valid midi file or not.
-        /// </summary>
-        /// <remarks>
-        ///     We add this here so content doesn't need to reference NFluidsynth.
-        /// </remarks>
-        bool IsMidiFile(string filename);
-
-        /// <summary>
-        ///     Checks whether the file at the given path is a valid midi file or not.
-        /// </summary>
-        /// <remarks>
-        ///     We add this here so content doesn't need to reference NFluidsynth.
-        /// </remarks>
-        bool IsSoundfontFile(string filename);
-        */
-
         /// <summary>
         ///     Method called every frame.
         ///     Should be used to update positional audio.
@@ -57,6 +43,11 @@ namespace Robust.Client.Audio.Midi
         /// <param name="frameTime"></param>
         void FrameUpdate(float frameTime);
 
+        /// <summary>
+        ///     Volume, in db.
+        /// </summary>
+        float Volume { get; set; }
+
         /// <summary>
         ///     If true, MIDI support is available.
         /// </summary>
@@ -72,9 +63,11 @@ namespace Robust.Client.Audio.Midi
         [Dependency] private readonly IEyeManager _eyeManager = default!;
         [Dependency] private readonly IResourceManagerInternal _resourceManager = default!;
         [Dependency] private readonly IEntityManager _entityManager = default!;
+        [Dependency] private readonly IConfigurationManager _cfgMan = default!;
 
         private SharedBroadPhaseSystem _broadPhaseSystem = default!;
 
+        [ViewVariables]
         public bool IsAvailable
         {
             get
@@ -85,12 +78,29 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
-        private readonly List<MidiRenderer> _renderers = new();
+        [ViewVariables]
+        private readonly List<IMidiRenderer> _renderers = new();
 
         private bool _alive = true;
         private Settings? _settings;
         private Thread? _midiThread;
         private ISawmill _midiSawmill = default!;
+        private float _volume = 0f;
+        private bool _volumeDirty = true;
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        public float Volume
+        {
+            get => _volume;
+            set
+            {
+                if (MathHelper.CloseTo(_volume, value))
+                    return;
+
+                _cfgMan.SetCVar(CVars.MidiVolume, value);
+                _volumeDirty = true;
+            }
+        }
 
         private static readonly string[] LinuxSoundfonts =
         {
@@ -117,12 +127,19 @@ namespace Robust.Client.Audio.Midi
         private NFluidsynth.Logger.LoggerDelegate _loggerDelegate = default!;
         private ISawmill _sawmill = default!;
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public int OcclusionCollisionMask { get; set; }
 
         private void InitializeFluidsynth()
         {
             if (FluidsynthInitialized || _failedInitialize) return;
 
+            _cfgMan.OnValueChanged(CVars.MidiVolume, value =>
+            {
+                _volume = value;
+                _volumeDirty = true;
+            }, true);
+
             _midiSawmill = Logger.GetSawmill("midi");
             _sawmill = Logger.GetSawmill("midi.fluidsynth");
             _loggerDelegate = LoggerDelegate;
@@ -175,18 +192,6 @@ namespace Robust.Client.Audio.Midi
             _sawmill.Log(rLevel, message);
         }
 
-        /*
-        public bool IsMidiFile(string filename)
-        {
-            return SoundFont.IsMidiFile(filename);
-        }
-
-        public bool IsSoundfontFile(string filename)
-        {
-            return SoundFont.IsSoundFont(filename);
-        }
-        */
-
         public IMidiRenderer? GetNewRenderer()
         {
             if (!FluidsynthInitialized)
@@ -250,7 +255,9 @@ namespace Robust.Client.Audio.Midi
                 }
 
                 lock (_renderers)
+                {
                     _renderers.Add(renderer);
+                }
 
                 return renderer;
             }
@@ -268,74 +275,79 @@ namespace Robust.Client.Audio.Midi
             }
 
             // Update positions of streams every frame.
-            lock (_renderers)
-                foreach (var renderer in _renderers)
+            foreach (var renderer in _renderers)
+            {
+                if (renderer.Disposed)
+                    continue;
+
+                if(_volumeDirty)
+                    renderer.Source.SetVolume(Volume);
+
+                if (!renderer.Mono)
                 {
-                    if (renderer.Disposed)
-                        continue;
-
-                    if (!renderer.Mono)
-                    {
-                        renderer.Source.SetGlobal();
-                        continue;
-                    }
-
-                    MapCoordinates? mapPos = null;
-                    if (renderer.TrackingCoordinates != null)
-                    {
-                        mapPos = renderer.TrackingCoordinates.Value.ToMap(_entityManager);
-                    }
-                    else if (renderer.TrackingEntity != null)
-                    {
-                        mapPos = renderer.TrackingEntity.Transform.MapPosition;
-                    }
-
-                    if (mapPos != null)
-                    {
-                        var pos = mapPos.Value;
-                        if (pos.MapId != _eyeManager.CurrentMap)
-                        {
-                            renderer.Source.SetVolume(-10000000);
-                        }
-                        else
-                        {
-                            var sourceRelative = _eyeManager.CurrentEye.Position.Position - pos.Position;
-                            var occlusion = 0f;
-                            if (sourceRelative.Length > 0)
-                            {
-                                occlusion = _broadPhaseSystem.IntersectRayPenetration(
-                                    pos.MapId,
-                                    new CollisionRay(
-                                        pos.Position,
-                                        sourceRelative.Normalized,
-                                        OcclusionCollisionMask),
-                                    sourceRelative.Length,
-                                    renderer.TrackingEntity);
-                            }
-                            renderer.Source.SetOcclusion(occlusion);
-                        }
-
-                        if (renderer.Source.SetPosition(pos.Position))
-                        {
-                            continue;
-                        }
-
-                        if (renderer.TrackingEntity != null)
-                        {
-                            renderer.Source.SetVelocity(renderer.TrackingEntity.GlobalLinearVelocity());
-                        }
-
-                        if (float.IsNaN(pos.Position.X) || float.IsNaN(pos.Position.Y))
-                        {
-                            // just duck out instead of move to NaN
-                            renderer.Source.SetOcclusion(float.MaxValue);
-                            continue;
-                        }
-
-                        _midiSawmill?.Warning("Interrupting positional audio, can't set position.");
-                        renderer.Source.StopPlaying();
-                    }
+                    renderer.Source.SetGlobal();
+                    continue;
                 }
+
+                MapCoordinates? mapPos = null;
+                if (renderer.TrackingCoordinates != null)
+                {
+                    mapPos = renderer.TrackingCoordinates.Value.ToMap(_entityManager);
+                }
+                else if (renderer.TrackingEntity != null)
+                {
+                    mapPos = renderer.TrackingEntity.Transform.MapPosition;
+                }
+
+                if (mapPos != null)
+                {
+                    var pos = mapPos.Value;
+                    if (pos.MapId != _eyeManager.CurrentMap)
+                    {
+                        renderer.Source.SetVolume(-10000000);
+                    }
+                    else
+                    {
+                        var sourceRelative = _eyeManager.CurrentEye.Position.Position - pos.Position;
+                        var occlusion = 0f;
+                        if (sourceRelative.Length > 0)
+                        {
+                            occlusion = _broadPhaseSystem.IntersectRayPenetration(
+                                pos.MapId,
+                                new CollisionRay(
+                                    pos.Position,
+                                    sourceRelative.Normalized,
+                                    OcclusionCollisionMask),
+                                sourceRelative.Length,
+                                renderer.TrackingEntity);
+                        }
+
+                        renderer.Source.SetOcclusion(occlusion);
+                    }
+
+                    if (renderer.Source.SetPosition(pos.Position))
+                    {
+                        continue;
+                    }
+
+                    if (renderer.TrackingEntity != null)
+                    {
+                        renderer.Source.SetVelocity(renderer.TrackingEntity.GlobalLinearVelocity());
+                    }
+
+                    if (float.IsNaN(pos.Position.X) || float.IsNaN(pos.Position.Y))
+                    {
+                        // just duck out instead of move to NaN
+                        renderer.Source.SetOcclusion(float.MaxValue);
+                        continue;
+                    }
+
+                    _midiSawmill?.Warning("Interrupting positional audio, can't set position.");
+                    renderer.Source.StopPlaying();
+                }
+            }
+
+            _volumeDirty = false;
         }
 
         /// <summary>
@@ -346,6 +358,7 @@ namespace Robust.Client.Audio.Midi
             while (_alive)
             {
                 lock (_renderers)
+                {
                     for (var i = 0; i < _renderers.Count; i++)
                     {
                         var renderer = _renderers[i];
@@ -353,10 +366,11 @@ namespace Robust.Client.Audio.Midi
                             renderer.Render();
                         else
                         {
-                            ((IMidiRenderer)renderer).InternalDispose();
+                            renderer.InternalDispose();
                             _renderers.Remove(renderer);
                         }
                     }
+                }
 
                 Thread.Sleep(1);
             }
@@ -367,9 +381,13 @@ namespace Robust.Client.Audio.Midi
             _alive = false;
             _midiThread?.Join();
             _settings?.Dispose();
-            foreach (var renderer in _renderers)
+
+            lock (_renderers)
             {
-                renderer?.Dispose();
+                foreach (var renderer in _renderers)
+                {
+                    renderer?.Dispose();
+                }
             }
 
             if (FluidsynthInitialized && !_failedInitialize)
@@ -424,6 +442,7 @@ namespace Robust.Client.Audio.Midi
                 var span = new Span<byte>(buf.ToPointer(), length);
                 var stream = _openStreams[(int) sfHandle];
 
+                // Fluidsynth's docs state that this method should leave the buffer unmodified if it fails. (returns -1)
                 try
                 {
                     // Fluidsynth does a LOT of tiny allocations (frankly, way too much).
@@ -447,6 +466,7 @@ namespace Robust.Client.Audio.Midi
                 {
                     return -1;
                 }
+
                 return 0;
             }
 
@@ -468,10 +488,12 @@ namespace Robust.Client.Audio.Midi
 
             public override int Close(IntPtr sfHandle)
             {
-                var stream = _openStreams[(int) sfHandle];
+                if (!_openStreams.Remove((int) sfHandle, out var stream))
+                    return -1;
+
                 stream.Dispose();
-                _openStreams.Remove((int) sfHandle);
                 return 0;
+
             }
         }
     }

Robust.Client/Audio/Midi/MidiRenderer.cs

@@ -7,7 +7,9 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
+using Robust.Shared.Maths;
 using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 using MidiEvent = NFluidsynth.MidiEvent;
 
 namespace Robust.Client.Audio.Midi
@@ -21,6 +23,17 @@ namespace Robust.Client.Audio.Midi
 
     public interface IMidiRenderer : IDisposable
     {
+
+        /// <summary>
+        ///     The buffered audio source of this renderer.
+        /// </summary>
+        internal IClydeBufferedAudioSource Source { get; }
+
+        /// <summary>
+        ///     Whether this renderer has been disposed or not.
+        /// </summary>
+        bool Disposed { get; }
+
         /// <summary>
         ///     This controls whether the midi file being played will loop or not.
         /// </summary>
@@ -110,6 +123,11 @@ namespace Robust.Client.Audio.Midi
         /// </summary>
         void StopAllNotes();
 
+        /// <summary>
+        ///     Render and play MIDI to the audio source.
+        /// </summary>
+        internal void Render();
+
         /// <summary>
         ///     Loads a new soundfont into the renderer.
         /// </summary>
@@ -159,7 +177,7 @@ namespace Robust.Client.Audio.Midi
         internal void InternalDispose();
     }
 
-    public class MidiRenderer : IMidiRenderer
+    internal class MidiRenderer : IMidiRenderer
     {
         [Dependency] private readonly IClydeAudio _clydeAudio = default!;
         [Dependency] private readonly ITaskManager _taskManager = default!;
@@ -186,10 +204,16 @@ namespace Robust.Client.Audio.Midi
         private const int SampleRate = 44100;
         private const int Buffers = SampleRate / 2205;
         private readonly object _playerStateLock = new();
+        private bool _debugEvents = false;
         private SequencerClientId _synthRegister;
+        private SequencerClientId _debugRegister;
         public IClydeBufferedAudioSource Source { get; set; }
+        IClydeBufferedAudioSource IMidiRenderer.Source => Source;
+
+        [ViewVariables]
         public bool Disposed { get; private set; } = false;
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public byte MidiProgram
         {
             get => _midiProgram;
@@ -203,6 +227,7 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public byte MidiBank
         {
             get => _midiBank;
@@ -216,6 +241,7 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public uint MidiSoundfont
         {
             get => _midiSoundfont;
@@ -229,10 +255,16 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public bool DisablePercussionChannel { get; set; } = true;
+
+        [ViewVariables(VVAccess.ReadWrite)]
         public bool DisableProgramChangeEvent { get; set; } = true;
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public int PlayerTotalTick => _player?.GetTotalTicks ?? 0;
+
+        [ViewVariables(VVAccess.ReadWrite)]
         public int PlayerTick
         {
             get => _player?.CurrentTick ?? 0;
@@ -243,12 +275,19 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public uint SequencerTick => _sequencer?.Tick ?? 0;
+
+        [ViewVariables(VVAccess.ReadWrite)]
         public double SequencerTimeScale => _sequencer?.TimeScale ?? 0;
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public bool Mono { get; set; }
+
+        [ViewVariables]
         public MidiRendererStatus Status { get; private set; } = MidiRendererStatus.None;
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public bool LoopMidi
         {
             get => _loopMidi;
@@ -260,10 +299,11 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public IEntity? TrackingEntity { get; set; } = null;
-        public EntityCoordinates? TrackingCoordinates { get; set; } = null;
 
-        internal bool Free { get; set; } = false;
+        [ViewVariables(VVAccess.ReadWrite)]
+        public EntityCoordinates? TrackingCoordinates { get; set; } = null;
 
         internal MidiRenderer(Settings settings, SoundFontLoader soundFontLoader, bool mono = true)
         {
@@ -276,6 +316,7 @@ namespace Robust.Client.Audio.Midi
             _soundFontLoader = soundFontLoader;
             _synth = new Synth(_settings);
             _sequencer = new Sequencer(false);
+            _debugRegister = _sequencer.RegisterClient("honk", DumpSequencerEvent);
             _synthRegister = _sequencer.RegisterFluidsynth(_synth);
 
             _synth.AddSoundFontLoader(soundFontLoader);
@@ -285,6 +326,27 @@ namespace Robust.Client.Audio.Midi
             Source.StartPlaying();
         }
 
+        private void DumpSequencerEvent(uint time, SequencerEvent @event)
+        {
+            // ReSharper disable once UseStringInterpolation
+            _midiSawmill.Debug(string.Format(
+                "{0:D8}: {1} chan:{2:D2} key:{3:D5} bank:{4:D2} ctrl:{5:D5} dur:{6:D5} pitch:{7:D5} prog:{8:D3} val:{9:D5} vel:{10:D5}",
+                time,
+                @event.Type.ToString().PadLeft(22),
+                @event.Channel,
+                @event.Key,
+                @event.Bank,
+                @event.Control,
+                @event.Duration,
+                @event.Pitch,
+                @event.Program,
+                @event.Value,
+                @event.Velocity));
+
+            @event.Dest = _synthRegister;
+            _sequencer.SendNow(@event);
+        }
+
         public bool OpenInput()
         {
             if (Disposed)
@@ -294,7 +356,11 @@ namespace Robust.Client.Audio.Midi
             Status = MidiRendererStatus.Input;
             StopAllNotes();
 
-            _driver = new MidiDriver(_settings, MidiDriverEventHandler);
+            lock (_playerStateLock)
+            {
+                _driver = new MidiDriver(_settings, MidiDriverEventHandler);
+            }
+
             return true;
         }
 
@@ -332,8 +398,13 @@ namespace Robust.Client.Audio.Midi
         {
             if (Status != MidiRendererStatus.Input) return false;
             Status = MidiRendererStatus.None;
-            _driver?.Dispose();
-            _driver = null;
+
+            lock (_playerStateLock)
+            {
+                _driver?.Dispose();
+                _driver = null;
+            }
+
             StopAllNotes();
             return true;
         }
@@ -357,7 +428,8 @@ namespace Robust.Client.Audio.Midi
 
         public void StopAllNotes()
         {
-            _synth.AllNotesOff(-1);
+            lock(_playerStateLock)
+                _synth.AllNotesOff(-1);
         }
 
         public void LoadSoundfont(string filename, bool resetPresets = false)
@@ -372,13 +444,15 @@ namespace Robust.Client.Audio.Midi
         public event Action<Shared.Audio.Midi.MidiEvent>? OnMidiEvent;
         public event Action? OnMidiPlayerFinished;
 
-        internal void Render(int length = SampleRate / 250)
+        void IMidiRenderer.Render()
+        {
+            Render();
+        }
+
+        private void Render(int length = SampleRate / 250)
         {
             if (Disposed) return;
 
-            // SSE needs this.
-            DebugTools.Assert(length % 4 == 0, "Sample length must be multiple of 4");
-
             var buffersProcessed = Source.GetNumberOfBuffersProcessed();
             if(buffersProcessed == Buffers) _midiSawmill.Warning("MIDI buffer overflow!");
             if (buffersProcessed == 0) return;
@@ -393,36 +467,16 @@ namespace Robust.Client.Audio.Midi
                 Source.GetBuffersProcessed(buffers);
 
                 lock (_playerStateLock)
+                {
+                    // _sequencer.Process(10);
                     _synth?.WriteSampleFloat(length * buffers.Length, audio, 0, Mono ? 1 : 2,
                         audio, Mono ? length * buffers.Length : 1, Mono ? 1 : 2);
-
+                }
                 if (Mono) // Turn audio to mono
                 {
                     var l = length * buffers.Length;
 
-                    if (Sse.IsSupported)
-                    {
-                        fixed (float* ptr = audio)
-                        {
-                            for (var j = 0; j < l; j += 4)
-                            {
-                                var k = j + l;
-
-                                var jV = Sse.LoadVector128(ptr + j);
-                                var kV = Sse.LoadVector128(ptr + k);
-
-                                Sse.Store(j + ptr, Sse.Add(jV, kV));
-                            }
-                        }
-                    }
-                    else
-                    {
-                        for (var j = 0; j < l; j++)
-                        {
-                            var k = j + l;
-                            audio[j] = ((audio[k] + audio[j]));
-                        }
-                    }
+                    NumericsHelpers.Add(audio[..l], audio[l..]);
                 }
 
                 for (var i = 0; i < buffers.Length; i++)
@@ -452,6 +506,7 @@ namespace Robust.Client.Audio.Midi
             var timestamp = SequencerTick;
             var midiEv = (Shared.Audio.Midi.MidiEvent) midiEvent;
             midiEv.Tick = timestamp;
+            midiEvent.Dispose();
             SendMidiEvent(midiEv);
             return 0;
         }
@@ -462,6 +517,7 @@ namespace Robust.Client.Audio.Midi
             var timestamp = SequencerTick;
             var midiEv = (Shared.Audio.Midi.MidiEvent) midiEvent;
             midiEv.Tick = timestamp;
+            midiEvent.Dispose();
             SendMidiEvent(midiEv);
             return 0;
         }
@@ -478,16 +534,16 @@ namespace Robust.Client.Audio.Midi
                 lock(_playerStateLock)
                     switch (midiEvent.Type)
                     {
-                        // Note On 0x80
-                        case 144:
-                            _synth.NoteOn(midiEvent.Channel, midiEvent.Key, midiEvent.Velocity);
-                            break;
-
-                        // Note Off - 0x90
+                        // Note Off - 0x80
                         case 128:
                             _synth.NoteOff(midiEvent.Channel, midiEvent.Key);
                             break;
 
+                        // Note On 0x90
+                        case 144:
+                            _synth.NoteOn(midiEvent.Channel, midiEvent.Key, midiEvent.Velocity);
+                            break;
+
                         // After Touch - 0xA
                         case 160:
                             _synth.KeyPressure(midiEvent.Channel, midiEvent.Key, midiEvent.Value);
@@ -522,6 +578,12 @@ namespace Robust.Client.Audio.Midi
                         case 81:
                         // System Messages - 0xF0
                         case 240:
+                            switch (midiEvent.Control)
+                            {
+                                case 11:
+                                    _synth.AllNotesOff(midiEvent.Channel);
+                                    break;
+                            }
                             return;
 
                         default:
@@ -543,7 +605,7 @@ namespace Robust.Client.Audio.Midi
             if (Disposed) return;
 
             var seqEv = (SequencerEvent) midiEvent;
-            seqEv.Dest = _synthRegister;
+            seqEv.Dest = _debugEvents ? _debugRegister : _synthRegister;
             _sequencer.SendAt(seqEv, time, absolute);
         }
 

Robust.Client/BaseClient.cs

@@ -13,6 +13,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -25,6 +26,7 @@ namespace Robust.Client
         [Dependency] private readonly IPlayerManager _playMan = default!;
         [Dependency] private readonly INetConfigurationManager _configManager = default!;
         [Dependency] private readonly IClientEntityManager _entityManager = default!;
+        [Dependency] private readonly IEntityLookup _entityLookup = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly IDiscordRichPresence _discord = default!;
         [Dependency] private readonly IGameTiming _timing = default!;
@@ -165,7 +167,7 @@ namespace Robust.Client
         ///     receiving states when they join the lobby.
         /// </summary>
         /// <param name="session">Session of the player.</param>
-        private void OnPlayerJoinedServer(IPlayerSession session)
+        private void OnPlayerJoinedServer(ICommonSession session)
         {
             DebugTools.Assert(RunLevel < ClientRunLevel.Connected);
             OnRunLevelChanged(ClientRunLevel.Connected);
@@ -175,20 +177,11 @@ namespace Robust.Client
             PlayerJoinedServer?.Invoke(this, new PlayerEventArgs(session));
         }
 
-        private void GameStartedSetup()
-        {
-            _entityManager.Startup();
-            _mapManager.Startup();
-
-            _timing.ResetSimTime();
-            _timing.Paused = false;
-        }
-
         /// <summary>
         ///     Player is joining the game
         /// </summary>
         /// <param name="session">Session of the player.</param>
-        private void OnPlayerJoinedGame(IPlayerSession session)
+        private void OnPlayerJoinedGame(ICommonSession session)
         {
             DebugTools.Assert(RunLevel >= ClientRunLevel.Connected);
             OnRunLevelChanged(ClientRunLevel.InGame);
@@ -218,12 +211,22 @@ namespace Robust.Client
             GameStoppedReset();
         }
 
+        private void GameStartedSetup()
+        {
+            _entityManager.Startup();
+            _mapManager.Startup();
+            _entityLookup.Startup();
+
+            _timing.ResetSimTime();
+            _timing.Paused = false;
+        }
+
         private void GameStoppedReset()
         {
             IoCManager.Resolve<INetConfigurationManager>().FlushMessages();
             _gameStates.Reset();
             _playMan.Shutdown();
-            IoCManager.Resolve<IEntityLookup>().Shutdown();
+            _entityLookup.Shutdown();
             _entityManager.Shutdown();
             _mapManager.Shutdown();
             _discord.ClearPresence();
@@ -295,12 +298,12 @@ namespace Robust.Client
         /// <summary>
         ///     The session that triggered the event.
         /// </summary>
-        private IPlayerSession? Session { get; }
+        private ICommonSession? Session { get; }
 
         /// <summary>
         ///     Constructs a new instance of the class.
         /// </summary>
-        public PlayerEventArgs(IPlayerSession? session)
+        public PlayerEventArgs(ICommonSession? session)
         {
             Session = session;
         }

Robust.Client/ClientIoC.cs

@@ -45,7 +45,7 @@ namespace Robust.Client
             IoCManager.Register<IMapManagerInternal, ClientMapManager>();
             IoCManager.Register<IClientMapManager, ClientMapManager>();
             IoCManager.Register<IEntityManager, ClientEntityManager>();
-            IoCManager.Register<IEntityLookup, SharedEntityLookup>();
+            IoCManager.Register<IEntityLookup, EntityLookup>();
             IoCManager.Register<IComponentFactory, ClientComponentFactory>();
             IoCManager.Register<ITileDefinitionManager, ClydeTileDefinitionManager>();
             IoCManager.Register<IClydeTileDefinitionManager, ClydeTileDefinitionManager>();

Robust.Client/CommandLineArgs.cs

@@ -17,6 +17,7 @@ namespace Robust.Client
         public bool Launcher { get; }
         public string? Username { get; }
         public IReadOnlyCollection<(string key, string value)> CVars { get; }
+        public IReadOnlyCollection<(string key, string value)> LogLevels { get; }
 
         // Manual parser because C# has no good command line parsing libraries. Also dependencies bad.
         // Also I don't like spending 100ms parsing command line args. Do you?
@@ -31,6 +32,7 @@ namespace Robust.Client
             var launcher = false;
             string? username = null;
             var cvars = new List<(string, string)>();
+            var logLevels = new List<(string, string)>();
             var mountOptions = new MountOptions();
 
             using var enumerator = args.GetEnumerator();
@@ -124,6 +126,26 @@ namespace Robust.Client
 
                     mountOptions.DirMounts.Add(enumerator.Current);
                 }
+                else if (arg == "--loglevel")
+                {
+                    if (!enumerator.MoveNext())
+                    {
+                        C.WriteLine("Missing loglevel sawmill.");
+                        return false;
+                    }
+
+                    var loglevel = enumerator.Current;
+                    DebugTools.AssertNotNull(loglevel);
+                    var pos = loglevel.IndexOf('=');
+
+                    if (pos == -1)
+                    {
+                        C.WriteLine("Expected = in loglevel.");
+                        return false;
+                    }
+
+                    logLevels.Add((loglevel[..pos], loglevel[(pos + 1)..]));
+                }
                 else if (arg == "--help")
                 {
                     PrintHelp();
@@ -142,6 +164,7 @@ namespace Robust.Client
                 launcher,
                 username,
                 cvars,
+                logLevels,
                 connectAddress,
                 ss14Address,
                 mountOptions);
@@ -162,6 +185,7 @@ Options:
   --launcher          Run in launcher mode (no main menu, auto connect).
   --username          Override username.
   --cvar              Specifies an additional cvar overriding the config file. Syntax is <key>=<value>
+  --loglevel          Specifies an additional sawmill log level overriding the default values. Syntax is <key>=<value>
   --mount-dir         Resource directory to mount.
   --mount-zip         Resource zip to mount.
   --help              Display this help text and exit.
@@ -175,6 +199,7 @@ Options:
             bool launcher,
             string? username,
             IReadOnlyCollection<(string key, string value)> cVars,
+            IReadOnlyCollection<(string key, string value)> logLevels,
             string connectAddress, string? ss14Address,
             MountOptions mountOptions)
         {
@@ -184,6 +209,7 @@ Options:
             Launcher = launcher;
             Username = username;
             CVars = cVars;
+            LogLevels = logLevels;
             ConnectAddress = connectAddress;
             Ss14Address = ss14Address;
             MountOptions = mountOptions;

Robust.Client/Console/ClientConsoleHost.cs

@@ -36,7 +36,7 @@ namespace Robust.Client.Console
             Message = message;
         }
     }
-    
+
     /// <inheritdoc cref="IClientConsoleHost" />
     internal class ClientConsoleHost : ConsoleHost, IClientConsoleHost
     {
@@ -45,9 +45,9 @@ namespace Robust.Client.Console
         /// <inheritdoc />
         public void Initialize()
         {
-            NetManager.RegisterNetMessage<MsgConCmdReg>(MsgConCmdReg.NAME, HandleConCmdReg);
-            NetManager.RegisterNetMessage<MsgConCmdAck>(MsgConCmdAck.NAME, HandleConCmdAck);
-            NetManager.RegisterNetMessage<MsgConCmd>(MsgConCmd.NAME, ProcessCommand);
+            NetManager.RegisterNetMessage<MsgConCmdReg>(HandleConCmdReg);
+            NetManager.RegisterNetMessage<MsgConCmdAck>(HandleConCmdAck);
+            NetManager.RegisterNetMessage<MsgConCmd>(ProcessCommand);
 
             Reset();
             LogManager.RootSawmill.AddHandler(new DebugConsoleLogHandler(this));

Robust.Client/Console/ScriptClient.cs

@@ -17,11 +17,11 @@ namespace Robust.Client.Console
 
         public void Initialize()
         {
-            _netManager.RegisterNetMessage<MsgScriptStop>(MsgScriptStop.NAME);
-            _netManager.RegisterNetMessage<MsgScriptEval>(MsgScriptEval.NAME);
-            _netManager.RegisterNetMessage<MsgScriptStart>(MsgScriptStart.NAME);
-            _netManager.RegisterNetMessage<MsgScriptResponse>(MsgScriptResponse.NAME, ReceiveScriptResponse);
-            _netManager.RegisterNetMessage<MsgScriptStartAck>(MsgScriptStartAck.NAME, ReceiveScriptStartAckResponse);
+            _netManager.RegisterNetMessage<MsgScriptStop>();
+            _netManager.RegisterNetMessage<MsgScriptEval>();
+            _netManager.RegisterNetMessage<MsgScriptStart>();
+            _netManager.RegisterNetMessage<MsgScriptResponse>(ReceiveScriptResponse);
+            _netManager.RegisterNetMessage<MsgScriptStartAck>(ReceiveScriptStartAckResponse);
         }
 
         private void ReceiveScriptStartAckResponse(MsgScriptStartAck message)
@@ -30,7 +30,8 @@ namespace Robust.Client.Console
 
             var console = new ScriptConsoleServer(this, session);
             _activeConsoles.Add(session, console);
-            console.Open();
+            // FIXME: When this is Open(), resizing the window will cause its position to get NaN'd.
+            console.OpenCentered();
         }
 
         private void ReceiveScriptResponse(MsgScriptResponse message)

Robust.Client/Debugging/DebugDrawing.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
@@ -23,7 +23,7 @@ namespace Robust.Client.Debugging
         [Dependency] private readonly IOverlayManager _overlayManager = default!;
         [Dependency] private readonly IEyeManager _eyeManager = default!;
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
-        [Dependency] private readonly IEntityManager _entityManager = default!;
+        [Dependency] private readonly IEntityLookup _lookup = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly IInputManager _inputManager = default!;
 
@@ -70,7 +70,7 @@ namespace Robust.Client.Debugging
 
                 if (value && !_overlayManager.HasOverlay<EntityPositionOverlay>())
                 {
-                    _overlayManager.AddOverlay(new EntityPositionOverlay(_entityManager, _eyeManager));
+                    _overlayManager.AddOverlay(new EntityPositionOverlay(_lookup, _eyeManager));
                 }
                 else
                 {
@@ -171,7 +171,7 @@ namespace Robust.Client.Debugging
                     // all entities have a TransformComponent
                     var transform = physBody.Owner.Transform;
 
-                    var worldBox = physBody.GetWorldAABB(_mapManager);
+                    var worldBox = physBody.GetWorldAABB();
                     if (worldBox.IsEmpty()) continue;
 
                     foreach (var fixture in physBody.Fixtures)
@@ -270,14 +270,14 @@ namespace Robust.Client.Debugging
 
         private sealed class EntityPositionOverlay : Overlay
         {
-            private readonly IEntityManager _entityManager;
+            private readonly IEntityLookup _lookup;
             private readonly IEyeManager _eyeManager;
 
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public EntityPositionOverlay(IEntityManager entityManager, IEyeManager eyeManager)
+            public EntityPositionOverlay(IEntityLookup lookup, IEyeManager eyeManager)
             {
-                _entityManager = entityManager;
+                _lookup = lookup;
                 _eyeManager = eyeManager;
             }
 
@@ -286,18 +286,17 @@ namespace Robust.Client.Debugging
                 const float stubLength = 0.25f;
 
                 var worldHandle = (DrawingHandleWorld) args.DrawingHandle;
-                foreach (var entity in _entityManager.GetEntities())
+                var viewport = _eyeManager.GetWorldViewport();
+
+                foreach (var entity in _lookup.GetEntitiesIntersecting(_eyeManager.CurrentMap, viewport))
                 {
                     var transform = entity.Transform;
-                    if (transform.MapID != _eyeManager.CurrentMap ||
-                        !_eyeManager.GetWorldViewport().Contains(transform.WorldPosition))
-                    {
-                        continue;
-                    }
 
                     var center = transform.WorldPosition;
-                    var xLine = transform.WorldRotation.RotateVec(Vector2.UnitX);
-                    var yLine = transform.WorldRotation.RotateVec(Vector2.UnitY);
+                    var worldRotation = transform.WorldRotation;
+
+                    var xLine = worldRotation.RotateVec(Vector2.UnitX);
+                    var yLine = worldRotation.RotateVec(Vector2.UnitY);
 
                     worldHandle.DrawLine(center, center + xLine * stubLength, Color.Red);
                     worldHandle.DrawLine(center, center + yLine * stubLength, Color.Green);

Robust.Client/Debugging/DebugDrawingManager.cs

@@ -1,12 +1,12 @@
-using Robust.Shared.IoC;
-using Robust.Shared.Network.Messages;
 using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
-using Robust.Shared.Maths;
-using Robust.Shared.Timing;
 using Robust.Shared.Enums;
+using Robust.Shared.IoC;
+using Robust.Shared.Maths;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Messages;
+using Robust.Shared.Timing;
 
 namespace Robust.Client.Debugging
 {
@@ -54,7 +54,7 @@ namespace Robust.Client.Debugging
 
         public void Initialize()
         {
-            _net.RegisterNetMessage<MsgRay>(MsgRay.NAME, HandleDrawRay);
+            _net.RegisterNetMessage<MsgRay>(HandleDrawRay);
         }
 
         private void HandleDrawRay(MsgRay msg)

Robust.Client/GameController/GameController.cs

@@ -125,7 +125,6 @@ namespace Robust.Client
             _prototypeManager.Resync();
             _mapManager.Initialize();
             _entityManager.Initialize();
-            IoCManager.Resolve<IEntityLookup>().Initialize();
             _gameStateManager.Initialize();
             _placementManager.Initialize();
             _viewVariablesManager.Initialize();
@@ -203,6 +202,26 @@ namespace Robust.Client
 
             SetupLogging(_logManager, logHandlerFactory ?? (() => new ConsoleLogHandler()));
 
+            if (_commandLineArgs != null)
+            {
+                foreach (var (sawmill, level) in _commandLineArgs.LogLevels)
+                {
+                    LogLevel? logLevel;
+                    if (level == "null")
+                        logLevel = null;
+                    else
+                    {
+                        if (!Enum.TryParse<LogLevel>(level, out var result))
+                        {
+                            System.Console.WriteLine($"LogLevel {level} does not exist!");
+                            continue;
+                        }
+                        logLevel = result;
+                    }
+                    _logManager.GetSawmill(sawmill).Level = logLevel;
+                }
+            }
+
             // Figure out user data directory.
             var userDataDir = GetUserDataDir();
 

Robust.Client/GameObjects/ClientComponentFactory.cs

@@ -9,58 +9,30 @@ namespace Robust.Client.GameObjects
         public ClientComponentFactory()
         {
             // Required for the engine to work
-            Register<MetaDataComponent>();
-            RegisterReference<MetaDataComponent, IMetaDataComponent>();
-
-            // Required for the engine to work
-            Register<TransformComponent>();
-            RegisterReference<TransformComponent, ITransformComponent>();
-
-            Register<MapComponent>();
-            RegisterReference<MapComponent, IMapComponent>();
-
-            Register<MapGridComponent>();
-            RegisterReference<MapGridComponent, IMapGridComponent>();
-
-            Register<PhysicsComponent>();
-            RegisterReference<PhysicsComponent, IPhysBody>();
-
-            Register<CollisionWakeComponent>();
-
-            Register<ContainerManagerComponent>();
-            RegisterReference<ContainerManagerComponent, IContainerManager>();
-
             RegisterIgnore("KeyBindingInput");
 
-            Register<InputComponent>();
-
-            Register<SpriteComponent>();
-            RegisterReference<SpriteComponent, SharedSpriteComponent>();
-            RegisterReference<SpriteComponent, ISpriteComponent>();
-
-            Register<ClientOccluderComponent>();
-            RegisterReference<ClientOccluderComponent, OccluderComponent>();
-
-            Register<EyeComponent>();
-            RegisterReference<EyeComponent, SharedEyeComponent>();
-
-            Register<AppearanceComponent>();
-            RegisterReference<AppearanceComponent, SharedAppearanceComponent>();
-
-            Register<AppearanceTestComponent>();
-            Register<SnapGridComponent>();
-
-            Register<ClientUserInterfaceComponent>();
-            RegisterReference<ClientUserInterfaceComponent, SharedUserInterfaceComponent>();
-
-            Register<AnimationPlayerComponent>();
-
-            Register<TimerComponent>();
+            RegisterClass<MetaDataComponent>();
+            RegisterClass<TransformComponent>();
+            RegisterClass<MapComponent>();
+            RegisterClass<MapGridComponent>();
+            RegisterClass<PhysicsComponent>();
+            RegisterClass<CollisionWakeComponent>();
+            RegisterClass<ClientUserInterfaceComponent>();
+            RegisterClass<ContainerManagerComponent>();
+            RegisterClass<InputComponent>();
+            RegisterClass<SpriteComponent>();
+            RegisterClass<ClientOccluderComponent>();
+            RegisterClass<EyeComponent>();
+            RegisterClass<AppearanceComponent>();
+            RegisterClass<AppearanceTestComponent>();
+            RegisterClass<SnapGridComponent>();
+            RegisterClass<AnimationPlayerComponent>();
+            RegisterClass<TimerComponent>();
 
 #if DEBUG
-            Register<DebugExceptionOnAddComponent>();
-            Register<DebugExceptionInitializeComponent>();
-            Register<DebugExceptionStartupComponent>();
+            RegisterClass<DebugExceptionOnAddComponent>();
+            RegisterClass<DebugExceptionInitializeComponent>();
+            RegisterClass<DebugExceptionStartupComponent>();
 #endif
 
         }

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -1,14 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using JetBrains.Annotations;
 using Prometheus;
 using Robust.Client.GameStates;
-using Robust.Shared.Exceptions;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
-using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Timing;
@@ -67,7 +62,7 @@ namespace Robust.Client.GameObjects
         /// <inheritdoc />
         public void SetupNetworking()
         {
-            _networkManager.RegisterNetMessage<MsgEntity>(MsgEntity.NAME, HandleEntityNetworkMessage);
+            _networkManager.RegisterNetMessage<MsgEntity>(HandleEntityNetworkMessage);
         }
 
         public override void TickUpdate(float frameTime, Histogram? histogram)
@@ -109,6 +104,7 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         public void SendComponentNetworkMessage(INetChannel? channel, IEntity entity, IComponent component, ComponentMessage message)
         {
             if (!component.NetID.HasValue)

Robust.Client/GameObjects/Components/Appearance/AppearanceComponent.cs

@@ -10,6 +10,7 @@ using YamlDotNet.RepresentationModel;
 
 namespace Robust.Client.GameObjects
 {
+    [ComponentReference(typeof(SharedAppearanceComponent))]
     public sealed class AppearanceComponent : SharedAppearanceComponent
     {
         [ViewVariables]

Robust.Client/GameObjects/Components/Eye/EyeComponent.cs

@@ -10,6 +10,7 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.GameObjects
 {
+    [ComponentReference(typeof(SharedEyeComponent))]
     public class EyeComponent : SharedEyeComponent
     {
         [Dependency] private readonly IEyeManager _eyeManager = default!;

Robust.Client/GameObjects/Components/Light/ClientOccluderComponent.cs

@@ -8,10 +8,11 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.GameObjects
 {
+    [ComponentReference(typeof(OccluderComponent))]
     internal sealed class ClientOccluderComponent : OccluderComponent
     {
         [Dependency] private readonly IMapManager _mapManager = default!;
-        
+
         [ViewVariables] private (GridId, Vector2i) _lastPosition;
         [ViewVariables] internal OccluderDir Occluding { get; private set; }
         [ViewVariables] internal uint UpdateGeneration { get; set; }

Robust.Client/GameObjects/Components/Light/PointLightComponent.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Animations;
@@ -167,7 +168,7 @@ namespace Robust.Client.GameObjects
             set
             {
                 _radius = MathF.Max(value, 0.01f); // setting radius to 0 causes exceptions, so just use a value close enough to zero that it's unnoticeable.
-                Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PointLightRadiusChangedMessage(this));
+                Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PointLightRadiusChangedEvent(this));
             }
         }
 
@@ -179,6 +180,18 @@ namespace Robust.Client.GameObjects
                 Mask = null;
         }
 
+        /// <summary>
+        /// What MapId we are intersecting for RenderingTreeSystem.
+        /// </summary>
+        [ViewVariables]
+        internal MapId IntersectingMapId { get; set; } = MapId.Nullspace;
+
+        /// <summary>
+        /// What grids we're on for RenderingTreeSystem.
+        /// </summary>
+        [ViewVariables]
+        internal List<GridId> IntersectingGrids = new();
+
         void ISerializationHooks.AfterDeserialization()
         {
             if (_maskPath != null)
@@ -230,7 +243,7 @@ namespace Robust.Client.GameObjects
             if (map != MapId.Nullspace)
             {
                 Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local,
-                    new RenderTreeRemoveLightMessage(this, map));
+                    new RenderTreeRemoveLightEvent(this, map));
             }
         }
 
@@ -248,11 +261,11 @@ namespace Robust.Client.GameObjects
         }
     }
 
-    public struct PointLightRadiusChangedMessage
+    public class PointLightRadiusChangedEvent : EntityEventArgs
     {
         public PointLightComponent PointLightComponent { get; }
 
-        public PointLightRadiusChangedMessage(PointLightComponent pointLightComponent)
+        public PointLightRadiusChangedEvent(PointLightComponent pointLightComponent)
         {
             PointLightComponent = pointLightComponent;
         }

Robust.Client/GameObjects/Components/Renderable/SpriteComponent.cs

@@ -27,6 +27,8 @@ using DrawDepthTag = Robust.Shared.GameObjects.DrawDepth;
 
 namespace Robust.Client.GameObjects
 {
+    [ComponentReference(typeof(SharedSpriteComponent))]
+    [ComponentReference(typeof(ISpriteComponent))]
     public sealed class SpriteComponent : SharedSpriteComponent, ISpriteComponent,
         IComponentDebug, ISerializationHooks
     {
@@ -123,6 +125,18 @@ namespace Robust.Client.GameObjects
         [DataField("directional")]
         private bool _directional = true;
 
+        /// <summary>
+        /// What MapId we are intersecting for RenderingTreeSystem.
+        /// </summary>
+        [ViewVariables]
+        internal MapId IntersectingMapId { get; set; } = MapId.Nullspace;
+
+        /// <summary>
+        /// What grids we're on for RenderingTreeSystem.
+        /// </summary>
+        [ViewVariables]
+        internal List<GridId> IntersectingGrids { get; } = new();
+
         [DataField("layerDatums")]
         private List<PrototypeLayerData> LayerDatums
         {
@@ -1345,18 +1359,6 @@ namespace Robust.Client.GameObjects
             return texture;
         }
 
-        public override void OnRemove()
-        {
-            base.OnRemove();
-
-            var map = Owner.Transform.MapID;
-            if (map != MapId.Nullspace)
-            {
-                Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local,
-                    new RenderTreeRemoveSpriteMessage(this, map));
-            }
-        }
-
         public void FrameUpdate(float delta)
         {
             foreach (var t in Layers)
@@ -1576,9 +1578,10 @@ namespace Robust.Client.GameObjects
         {
             var builder = new StringBuilder();
             builder.AppendFormat(
-                "vis/depth/scl/rot/ofs/col/diral/dir: {0}/{1}/{2}/{3}/{4}/{5}/{6}/{7}\n",
+                "vis/depth/scl/rot/ofs/col/norot/override/dir: {0}/{1}/{2}/{3}/{4}/{5}/{6}/{8}/{7}\n",
                 Visible, DrawDepth, Scale, Rotation, Offset,
-                Color, Directional, GetDir(RSI.State.DirectionType.Dir8, Owner.Transform.WorldRotation)
+                Color, NoRotation, GetDir(RSI.State.DirectionType.Dir8, Owner.Transform.WorldRotation),
+                DirectionOverride
             );
 
             foreach (var layer in Layers)
@@ -2176,6 +2179,10 @@ namespace Robust.Client.GameObjects
                 return null;
             }
 
+            public void QueueDelete()
+            {
+            }
+
             public void Delete()
             {
             }
@@ -2190,10 +2197,12 @@ namespace Robust.Client.GameObjects
                 return Enumerable.Empty<T>();
             }
 
+            [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
             public void SendMessage(IComponent? owner, ComponentMessage message)
             {
             }
 
+            [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
             public void SendNetworkMessage(IComponent owner, ComponentMessage message, INetChannel? channel = null)
             {
             }

Robust.Client/GameObjects/Components/UserInterface/ClientUserInterfaceComponent.cs

@@ -2,14 +2,14 @@
 using System.Collections.Generic;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Network;
-using Robust.Shared.Players;
 using Robust.Shared.Reflection;
 using Robust.Shared.Serialization;
 using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.GameObjects
 {
+    [ComponentReference(typeof(SharedUserInterfaceComponent))]
     public class ClientUserInterfaceComponent : SharedUserInterfaceComponent, ISerializationHooks
     {
         [Dependency] private readonly IReflectionManager _reflectionManager = default!;
@@ -23,6 +23,9 @@ namespace Robust.Client.GameObjects
         [DataField("interfaces", readOnly: true)]
         private List<PrototypeData> _interfaceData = new();
 
+        [ViewVariables]
+        public IEnumerable<BoundUserInterface> Interfaces => _openInterfaces.Values;
+
         void ISerializationHooks.AfterDeserialization()
         {
             _interfaces.Clear();
@@ -33,48 +36,40 @@ namespace Robust.Client.GameObjects
             }
         }
 
-        public override void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel,
-            ICommonSession? session = null)
+        internal void MessageReceived(BoundUIWrapMessage msg)
         {
-            base.HandleNetworkMessage(message, netChannel, session);
-
-            switch (message)
+            switch (msg.Message)
             {
-                case BoundInterfaceMessageWrapMessage wrapped:
-                    // Double nested switches who needs readability anyways.
-                    switch (wrapped.Message)
+                case OpenBoundInterfaceMessage _:
+                    if (_openInterfaces.ContainsKey(msg.UiKey))
                     {
-                        case OpenBoundInterfaceMessage _:
-                            if (_openInterfaces.ContainsKey(wrapped.UiKey))
-                            {
-                                return;
-                            }
+                        return;
+                    }
 
-                            OpenInterface(wrapped);
-                            break;
+                    OpenInterface(msg);
+                    break;
 
-                        case CloseBoundInterfaceMessage _:
-                            Close(wrapped.UiKey, true);
-                            break;
+                case CloseBoundInterfaceMessage _:
+                    Close(msg.UiKey, true);
+                    break;
 
-                        default:
-                            if (_openInterfaces.TryGetValue(wrapped.UiKey, out var bi))
-                            {
-                                bi.InternalReceiveMessage(wrapped.Message);
-                            }
-                            break;
+                default:
+                    if (_openInterfaces.TryGetValue(msg.UiKey, out var bi))
+                    {
+                        bi.InternalReceiveMessage(msg.Message);
                     }
 
                     break;
             }
         }
 
-        private void OpenInterface(BoundInterfaceMessageWrapMessage wrapped)
+        private void OpenInterface(BoundUIWrapMessage wrapped)
         {
             var data = _interfaces[wrapped.UiKey];
             // TODO: This type should be cached, but I'm too lazy.
             var type = _reflectionManager.LooseGetType(data.ClientType);
-            var boundInterface = (BoundUserInterface) _dynamicTypeFactory.CreateInstance(type, new[]{this, wrapped.UiKey});
+            var boundInterface =
+                (BoundUserInterface) _dynamicTypeFactory.CreateInstance(type, new[] {this, wrapped.UiKey});
             boundInterface.Open();
             _openInterfaces[wrapped.UiKey] = boundInterface;
         }
@@ -86,7 +81,7 @@ namespace Robust.Client.GameObjects
                 return;
             }
 
-            if(!remoteCall)
+            if (!remoteCall)
                 SendMessage(new CloseBoundInterfaceMessage(), uiKey);
             _openInterfaces.Remove(uiKey);
             boundUserInterface.Dispose();
@@ -94,7 +89,8 @@ namespace Robust.Client.GameObjects
 
         internal void SendMessage(BoundUserInterfaceMessage message, object uiKey)
         {
-            SendNetworkMessage(new BoundInterfaceMessageWrapMessage(message, uiKey));
+            EntitySystem.Get<UserInterfaceSystem>()
+                .Send(new BoundUIWrapMessage(Owner.Uid, message, uiKey));
         }
     }
 

Robust.Client/GameObjects/EntitySystems/AudioSystem.cs

@@ -41,17 +41,6 @@ namespace Robust.Client.GameObjects
             _broadPhaseSystem = Get<SharedBroadPhaseSystem>();
         }
 
-        public override void Shutdown()
-        {
-            base.Shutdown();
-            UnsubscribeNetworkEvent<PlayAudioEntityMessage>();
-            UnsubscribeNetworkEvent<PlayAudioGlobalMessage>();
-            UnsubscribeNetworkEvent<PlayAudioPositionalMessage>();
-            UnsubscribeNetworkEvent<StopAudioMessageClient>();
-
-            UnsubscribeLocalEvent<SoundSystem.QueryAudioSystem>();
-        }
-
         private void StopAudioMessageHandler(StopAudioMessageClient ev)
         {
             var stream = _playingClydeStreams.Find(p => p.NetIdentifier == ev.Identifier);
@@ -265,7 +254,7 @@ namespace Robust.Client.GameObjects
             if (!source.SetPosition(entity.Transform.WorldPosition))
             {
                 source.Dispose();
-                Logger.Warning("Can't play positional audio, can't set position.");
+                Logger.Warning($"Can't play positional audio \"{stream.Name}\", can't set position.");
                 return null;
             }
 
@@ -312,7 +301,7 @@ namespace Robust.Client.GameObjects
             if (!source.SetPosition(coordinates.ToMapPos(EntityManager)))
             {
                 source.Dispose();
-                Logger.Warning("Can't play positional audio, can't set position.");
+                Logger.Warning("Can't play positional audio \"{stream.Name}\", can't set position.");
                 return null;
             }
 

Robust.Client/GameObjects/EntitySystems/ClientOccluderSystem.cs

@@ -38,15 +38,6 @@ namespace Robust.Client.GameObjects
             SubscribeLocalEvent<ClientOccluderComponent, SnapGridPositionChangedEvent>(HandleSnapGridMove);
         }
 
-        /// <inheritdoc />
-        public override void Shutdown()
-        {
-            UnsubscribeLocalEvent<OccluderDirtyEvent>();
-            UnsubscribeLocalEvent<ClientOccluderComponent, SnapGridPositionChangedEvent>();
-
-            base.Shutdown();
-        }
-
         public override void FrameUpdate(float frameTime)
         {
             base.FrameUpdate(frameTime);

Robust.Client/GameObjects/EntitySystems/DebugGridTileLookupSystem.cs

@@ -0,0 +1,134 @@
+#if DEBUG
+using System;
+using System.Text;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Client.UserInterface;
+using Robust.Client.UserInterface.Controls;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+
+namespace Robust.Client.GameObjects
+{
+    internal sealed class DebugGridTileLookupSystem : EntitySystem
+    {
+        [Dependency] private readonly IEyeManager _eyeManager = default!;
+        [Dependency] private readonly IInputManager _inputManager = default!;
+        [Dependency] private readonly IMapManager _mapManager = default!;
+
+        public bool Enabled
+        {
+            get => _enabled;
+            set
+            {
+                if (_enabled == value) return;
+                _enabled = value;
+
+                if (_enabled)
+                {
+                    _label.Visible = true;
+                    LastTile = default;
+                }
+                else
+                {
+                    _label.Text = null;
+                    _label.Visible = false;
+                }
+            }
+        }
+
+        private bool _enabled;
+
+        private (GridId Grid, Vector2i Indices) LastTile;
+
+        // Label and shit that follows cursor
+        private Label _label = new()
+        {
+            Visible = false,
+        };
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            SubscribeNetworkEvent<SendGridTileLookupMessage>(HandleSentEntities);
+            IoCManager.Resolve<IUserInterfaceManager>().StateRoot.AddChild(_label);
+        }
+
+        public override void Shutdown()
+        {
+            base.Shutdown();
+            UnsubscribeNetworkEvent<SendGridTileLookupMessage>();
+            IoCManager.Resolve<IUserInterfaceManager>().StateRoot.RemoveChild(_label);
+        }
+
+        private void RequestEntities(GridId gridId, Vector2i indices)
+        {
+            if (gridId == GridId.Invalid) return;
+            RaiseNetworkEvent(new RequestGridTileLookupMessage(gridId, indices));
+        }
+
+        private void HandleSentEntities(SendGridTileLookupMessage message)
+        {
+            if (!Enabled) return;
+            var text = new StringBuilder();
+            text.AppendLine($"GridId: {LastTile.Grid}, Tile: {LastTile.Indices}");
+
+            for (var i = 0; i < message.Entities.Count; i++)
+            {
+                var uid = message.Entities[i];
+
+                if (!EntityManager.TryGetEntity(uid, out var entity)) continue;
+
+                text.AppendLine(entity.ToString());
+            }
+
+            _label.Text = text.ToString();
+        }
+
+        public override void FrameUpdate(float frameTime)
+        {
+            base.FrameUpdate(frameTime);
+            if (!Enabled) return;
+
+            var mousePos = _inputManager.MouseScreenPosition;
+            var worldPos = _eyeManager.ScreenToMap(mousePos);
+
+            GridId gridId;
+            Vector2i tile;
+
+            if (_mapManager.TryFindGridAt(worldPos, out var grid))
+            {
+                gridId = grid.Index;
+                tile = grid.WorldToTile(worldPos.Position);
+            }
+            else
+            {
+                gridId = GridId.Invalid;
+                tile = new Vector2i((int) MathF.Floor(worldPos.Position.X), (int) MathF.Floor(worldPos.Position.Y));
+            }
+
+            LayoutContainer.SetPosition(_label, mousePos.Position);
+
+            if ((gridId, tile).Equals(LastTile)) return;
+
+            _label.Text = null;
+            LastTile = (gridId, tile);
+            RequestEntities(gridId, tile);
+        }
+    }
+
+    internal sealed class RequestTileEntities : IConsoleCommand
+    {
+        public string Command => "tilelookup";
+        public string Description => "Used for debugging GridTileLookupSystem";
+        public string Help => $"{Command}";
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            EntitySystem.Get<DebugGridTileLookupSystem>().Enabled ^= true;
+        }
+    }
+}
+#endif

Robust.Client/GameObjects/EntitySystems/RenderingTreeSystem.cs

@@ -1,4 +1,6 @@
 using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
 using JetBrains.Annotations;
 using Robust.Client.Physics;
 using Robust.Shared.GameObjects;
@@ -6,6 +8,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
+using Robust.Shared.Utility;
 
 namespace Robust.Client.GameObjects
 {
@@ -47,14 +50,171 @@ namespace Robust.Client.GameObjects
             _mapManager.OnGridCreated += MapManagerOnGridCreated;
             _mapManager.OnGridRemoved += MapManagerOnGridRemoved;
 
-            SubscribeLocalEvent<EntMapIdChangedMessage>(EntMapIdChanged);
-            SubscribeLocalEvent<MoveEvent>(EntMoved);
-            SubscribeLocalEvent<EntParentChangedMessage>(EntParentChanged);
-            SubscribeLocalEvent<PointLightRadiusChangedMessage>(PointLightRadiusChanged);
-            SubscribeLocalEvent<RenderTreeRemoveSpriteMessage>(RemoveSprite);
-            SubscribeLocalEvent<RenderTreeRemoveLightMessage>(RemoveLight);
+            // Due to how recursion works, this must be done.
+            SubscribeLocalEvent<MoveEvent>(AnythingMoved);
+
+            SubscribeLocalEvent<SpriteComponent, EntMapIdChangedMessage>(SpriteMapChanged);
+            SubscribeLocalEvent<SpriteComponent, MoveEvent>(SpriteMoved);
+            SubscribeLocalEvent<SpriteComponent, EntParentChangedMessage>(SpriteParentChanged);
+            SubscribeLocalEvent<SpriteComponent, ComponentRemove>(RemoveSprite);
+
+            SubscribeLocalEvent<PointLightComponent, EntMapIdChangedMessage>(LightMapChanged);
+            SubscribeLocalEvent<PointLightComponent, MoveEvent>(LightMoved);
+            SubscribeLocalEvent<PointLightComponent, EntParentChangedMessage>(LightParentChanged);
+            SubscribeLocalEvent<PointLightComponent, PointLightRadiusChangedEvent>(PointLightRadiusChanged);
+            SubscribeLocalEvent<PointLightComponent, RenderTreeRemoveLightEvent>(RemoveLight);
         }
 
+        private void AnythingMoved(MoveEvent args)
+        {
+            AnythingMovedSubHandler(args.Sender.Transform);
+        }
+
+        private void AnythingMovedSubHandler(ITransformComponent sender)
+        {
+            // This recursive search is needed, as MoveEvent is defined to not care about indirect events like children.
+            // WHATEVER YOU DO, DON'T REPLACE THIS WITH SPAMMING EVENTS UNLESS YOU HAVE A GUARANTEE IT WON'T LAG THE GC.
+            // (Struct-based events ok though)
+            if (sender.Owner.TryGetComponent(out SpriteComponent? sprite))
+                QueueSpriteUpdate(sprite);
+            if (sender.Owner.TryGetComponent(out PointLightComponent? light))
+                QueueLightUpdate(light);
+            foreach (ITransformComponent child in sender.Children)
+            {
+                AnythingMovedSubHandler(child);
+            }
+        }
+
+        // For the RemoveX methods
+        // If the Transform is removed BEFORE the Sprite/Light,
+        // then the MapIdChanged code will handle and remove it (because MapId gets set to nullspace).
+        // Otherwise these will still have their past MapId and that's all we need..
+
+        #region SpriteHandlers
+        private void SpriteMapChanged(EntityUid uid, SpriteComponent component, EntMapIdChangedMessage args)
+        {
+            QueueSpriteUpdate(component);
+        }
+
+        private void SpriteMoved(EntityUid uid, SpriteComponent component, MoveEvent args)
+        {
+            QueueSpriteUpdate(component);
+        }
+
+        private void SpriteParentChanged(EntityUid uid, SpriteComponent component, EntParentChangedMessage args)
+        {
+            QueueSpriteUpdate(component);
+        }
+
+        private void RemoveSprite(EntityUid uid, SpriteComponent component, ComponentRemove args)
+        {
+            ClearSprite(component);
+        }
+
+        private void ClearSprite(SpriteComponent component)
+        {
+            if (_gridTrees.TryGetValue(component.IntersectingMapId, out var gridTrees))
+            {
+                foreach (var gridId in component.IntersectingGrids)
+                {
+                    if (!gridTrees.TryGetValue(gridId, out var tree)) continue;
+                    tree.SpriteTree.Remove(component);
+                }
+            }
+
+            component.IntersectingGrids.Clear();
+        }
+
+        private void QueueSpriteUpdate(SpriteComponent component)
+        {
+            if (component.TreeUpdateQueued) return;
+
+            component.TreeUpdateQueued = true;
+            _spriteQueue.Add(component);
+
+            foreach (var child in component.Owner.Transform.Children)
+            {
+                QueueSpriteUpdate(child.Owner);
+            }
+        }
+
+        private void QueueSpriteUpdate(IEntity entity)
+        {
+            if (!entity.TryGetComponent(out SpriteComponent? spriteComponent)) return;
+            QueueSpriteUpdate(spriteComponent);
+
+            foreach (var child in entity.Transform.Children)
+            {
+                QueueSpriteUpdate(child.Owner);
+            }
+        }
+        #endregion
+
+        #region LightHandlers
+        private void LightMapChanged(EntityUid uid, PointLightComponent component, EntMapIdChangedMessage args)
+        {
+            QueueLightUpdate(component);
+        }
+
+        private void LightMoved(EntityUid uid, PointLightComponent component, MoveEvent args)
+        {
+            QueueLightUpdate(component);
+        }
+
+        private void LightParentChanged(EntityUid uid, PointLightComponent component, EntParentChangedMessage args)
+        {
+            QueueLightUpdate(component);
+        }
+
+        private void PointLightRadiusChanged(EntityUid uid, PointLightComponent component, PointLightRadiusChangedEvent args)
+        {
+            QueueLightUpdate(component);
+        }
+
+        private void RemoveLight(EntityUid uid, PointLightComponent component, RenderTreeRemoveLightEvent args)
+        {
+            ClearLight(component);
+        }
+
+        private void ClearLight(PointLightComponent component)
+        {
+            if (_gridTrees.TryGetValue(component.IntersectingMapId, out var gridTrees))
+            {
+                foreach (var gridId in component.IntersectingGrids)
+                {
+                    if (!gridTrees.TryGetValue(gridId, out var tree)) continue;
+                    tree.LightTree.Remove(component);
+                }
+            }
+
+            component.IntersectingGrids.Clear();
+        }
+
+        private void QueueLightUpdate(PointLightComponent component)
+        {
+            if (component.TreeUpdateQueued) return;
+
+            component.TreeUpdateQueued = true;
+            _lightQueue.Add(component);
+
+            foreach (var child in component.Owner.Transform.Children)
+            {
+                QueueLightUpdate(child.Owner);
+            }
+        }
+
+        private void QueueLightUpdate(IEntity entity)
+        {
+            if (!entity.TryGetComponent(out PointLightComponent? lightComponent)) return;
+            QueueLightUpdate(lightComponent);
+
+            foreach (var child in entity.Transform.Children)
+            {
+                QueueLightUpdate(child.Owner);
+            }
+        }
+        #endregion
+
         public override void Shutdown()
         {
             base.Shutdown();
@@ -62,136 +222,27 @@ namespace Robust.Client.GameObjects
             _mapManager.MapDestroyed -= MapManagerOnMapDestroyed;
             _mapManager.OnGridCreated -= MapManagerOnGridCreated;
             _mapManager.OnGridRemoved -= MapManagerOnGridRemoved;
-
-            UnsubscribeLocalEvent<EntMapIdChangedMessage>();
-            UnsubscribeLocalEvent<MoveEvent>();
-            UnsubscribeLocalEvent<EntParentChangedMessage>();
-            UnsubscribeLocalEvent<PointLightRadiusChangedMessage>();
-            UnsubscribeLocalEvent<RenderTreeRemoveSpriteMessage>();
-            UnsubscribeLocalEvent<RenderTreeRemoveLightMessage>();
-        }
-
-        // For these next 2 methods (the Remove* ones):
-        // If the Transform is removed BEFORE the Sprite/Light,
-        // then the MapIdChanged code will handle and remove it (because MapId gets set to nullspace).
-        // Otherwise these will still have their past MapId and that's all we need..
-        private void RemoveLight(RenderTreeRemoveLightMessage ev)
-        {
-            foreach (var gridId in _mapManager.FindGridIdsIntersecting(ev.Map, MapTrees.LightAabbFunc(ev.Light), true))
-            {
-                _gridTrees[ev.Map][gridId].LightTree.Remove(ev.Light);
-            }
-        }
-
-        private void RemoveSprite(RenderTreeRemoveSpriteMessage ev)
-        {
-            foreach (var gridId in _mapManager.FindGridIdsIntersecting(ev.Map, MapTrees.SpriteAabbFunc(ev.Sprite), true))
-            {
-                _gridTrees[ev.Map][gridId].SpriteTree.Remove(ev.Sprite);
-            }
-        }
-
-        private void PointLightRadiusChanged(PointLightRadiusChangedMessage ev)
-        {
-            QueueUpdateLight(ev.PointLightComponent);
-        }
-
-        private void EntParentChanged(EntParentChangedMessage ev)
-        {
-            UpdateEntity(ev.Entity);
-        }
-
-        private void EntMoved(MoveEvent ev)
-        {
-            UpdateEntity(ev.Sender);
-        }
-
-        private void UpdateEntity(IEntity entity)
-        {
-            if (entity.TryGetComponent(out SpriteComponent? spriteComponent))
-            {
-                if (!spriteComponent.TreeUpdateQueued)
-                {
-                    spriteComponent.TreeUpdateQueued = true;
-
-                    _spriteQueue.Add(spriteComponent);
-                }
-            }
-
-            if (entity.TryGetComponent(out PointLightComponent? light))
-            {
-                QueueUpdateLight(light);
-            }
-
-            foreach (var child in entity.Transform.ChildEntityUids)
-            {
-                UpdateEntity(EntityManager.GetEntity(child));
-            }
-        }
-
-        private void QueueUpdateLight(PointLightComponent light)
-        {
-            if (!light.TreeUpdateQueued)
-            {
-                light.TreeUpdateQueued = true;
-
-                _lightQueue.Add(light);
-            }
-        }
-
-        private void EntMapIdChanged(EntMapIdChangedMessage ev)
-        {
-            // Nullspace is a valid map ID for stuff to have but we also aren't gonna bother indexing it.
-            // So that's why there's a GetValueOrDefault.
-            var oldMapTrees = _gridTrees.GetValueOrDefault(ev.OldMapId);
-            var newMapTrees = _gridTrees.GetValueOrDefault(ev.Entity.Transform.MapID);
-
-            // TODO: MMMM probably a better way to do this.
-            if (ev.Entity.TryGetComponent(out SpriteComponent? sprite))
-            {
-                if (oldMapTrees != null)
-                {
-                    foreach (var (_, gridTree) in oldMapTrees)
-                    {
-                        gridTree.SpriteTree.Remove(sprite);
-                    }
-                }
-
-                var bounds = MapTrees.SpriteAabbFunc(sprite);
-
-                foreach (var gridId in _mapManager.FindGridIdsIntersecting(ev.Entity.Transform.MapID, bounds, true))
-                {
-                    var gridBounds = gridId == GridId.Invalid
-                        ? bounds : bounds.Translated(-_mapManager.GetGrid(gridId).WorldPosition);
-
-                    newMapTrees?[gridId].SpriteTree.AddOrUpdate(sprite, gridBounds);
-                }
-            }
-
-            if (ev.Entity.TryGetComponent(out PointLightComponent? light))
-            {
-                if (oldMapTrees != null)
-                {
-                    foreach (var (_, gridTree) in oldMapTrees)
-                    {
-                        gridTree.LightTree.Remove(light);
-                    }
-                }
-
-                var bounds = MapTrees.LightAabbFunc(light);
-
-                foreach (var gridId in _mapManager.FindGridIdsIntersecting(ev.Entity.Transform.MapID, bounds, true))
-                {
-                    var gridBounds = gridId == GridId.Invalid
-                        ? bounds : bounds.Translated(-_mapManager.GetGrid(gridId).WorldPosition);
-
-                    newMapTrees?[gridId].LightTree.AddOrUpdate(light, gridBounds);
-                }
-            }
         }
 
         private void MapManagerOnMapDestroyed(object? sender, MapEventArgs e)
         {
+            foreach (var (_, gridTree) in _gridTrees[e.Map])
+            {
+                foreach (var comp in gridTree.LightTree)
+                {
+                    comp.IntersectingGrids.Clear();
+                }
+
+                foreach (var comp in gridTree.SpriteTree)
+                {
+                    comp.IntersectingGrids.Clear();
+                }
+
+                // Just in case?
+                gridTree.LightTree.Clear();
+                gridTree.SpriteTree.Clear();
+            }
+
             _gridTrees.Remove(e.Map);
         }
 
@@ -215,47 +266,109 @@ namespace Robust.Client.GameObjects
 
         private void MapManagerOnGridRemoved(MapId mapId, GridId gridId)
         {
+            var gridTree = _gridTrees[mapId][gridId];
+
+            foreach (var sprite in gridTree.SpriteTree)
+            {
+                sprite.IntersectingGrids.Remove(gridId);
+            }
+
+            foreach (var light in gridTree.LightTree)
+            {
+                light.IntersectingGrids.Remove(gridId);
+            }
+
+            // Clear in case
+            gridTree.LightTree.Clear();
+            gridTree.SpriteTree.Clear();
             _gridTrees[mapId].Remove(gridId);
         }
 
         public override void FrameUpdate(float frameTime)
         {
-            foreach (var queuedUpdateSprite in _spriteQueue)
+            foreach (var sprite in _spriteQueue)
             {
-                var map = queuedUpdateSprite.Owner.Transform.MapID;
-                if (map == MapId.Nullspace)
+                var mapId = sprite.Owner.Transform.MapID;
+
+                // If we're on a new map then clear the old one.
+                if (sprite.IntersectingMapId != mapId)
                 {
-                    continue;
+                    ClearSprite(sprite);
                 }
 
-                var mapTree = _gridTrees[map];
+                sprite.IntersectingMapId = mapId;
 
-                foreach (var gridId in _mapManager.FindGridIdsIntersecting(map,
-                    MapTrees.SpriteAabbFunc(queuedUpdateSprite), true))
+                if (mapId == MapId.Nullspace) continue;
+
+                var mapTree = _gridTrees[mapId];
+                var aabb = MapTrees.SpriteAabbFunc(sprite);
+                var intersectingGrids = _mapManager.FindGridIdsIntersecting(mapId, aabb, true).ToList();
+
+                // Remove from old
+                foreach (var gridId in sprite.IntersectingGrids)
                 {
-                    mapTree[gridId].SpriteTree.AddOrUpdate(queuedUpdateSprite);
+                    if (intersectingGrids.Contains(gridId)) continue;
+                    mapTree[gridId].SpriteTree.Remove(sprite);
                 }
 
-                queuedUpdateSprite.TreeUpdateQueued = false;
+                // Rebuild in the update below
+                sprite.IntersectingGrids.Clear();
+
+                // Update / add to new
+                foreach (var gridId in intersectingGrids)
+                {
+                    var translated = aabb.Translated(gridId == GridId.Invalid
+                        ? Vector2.Zero
+                        : -_mapManager.GetGrid(gridId).WorldPosition);
+
+                    mapTree[gridId].SpriteTree.AddOrUpdate(sprite, translated);
+
+                    sprite.IntersectingGrids.Add(gridId);
+                }
+
+                sprite.TreeUpdateQueued = false;
             }
 
-            foreach (var queuedUpdateLight in _lightQueue)
+            foreach (var light in _lightQueue)
             {
-                var map = queuedUpdateLight.Owner.Transform.MapID;
-                if (map == MapId.Nullspace)
+                var mapId = light.Owner.Transform.MapID;
+
+                // If we're on a new map then clear the old one.
+                if (light.IntersectingMapId != mapId)
                 {
-                    continue;
+                    ClearLight(light);
                 }
 
-                var mapTree = _gridTrees[map];
+                light.IntersectingMapId = mapId;
 
-                foreach (var gridId in _mapManager.FindGridIdsIntersecting(map,
-                    MapTrees.LightAabbFunc(queuedUpdateLight), true))
+                if (mapId == MapId.Nullspace) continue;
+
+                var mapTree = _gridTrees[mapId];
+                var aabb = MapTrees.LightAabbFunc(light);
+                var intersectingGrids = _mapManager.FindGridIdsIntersecting(mapId, aabb, true).ToList();
+
+                // Remove from old
+                foreach (var gridId in intersectingGrids)
                 {
-                    mapTree[gridId].LightTree.AddOrUpdate(queuedUpdateLight);
+                    if (intersectingGrids.Contains(gridId)) continue;
+                    mapTree[gridId].LightTree.Remove(light);
                 }
 
-                queuedUpdateLight.TreeUpdateQueued = false;
+                // Rebuild in the update below
+                light.IntersectingGrids.Clear();
+
+                // Update / add to new
+                foreach (var gridId in intersectingGrids)
+                {
+                    var translated = aabb.Translated(gridId == GridId.Invalid
+                        ? Vector2.Zero
+                        : -_mapManager.GetGrid(gridId).WorldPosition);
+
+                    mapTree[gridId].LightTree.AddOrUpdate(light, translated);
+                    light.IntersectingGrids.Add(gridId);
+                }
+
+                light.TreeUpdateQueued = false;
             }
 
             _spriteQueue.Clear();
@@ -290,21 +403,9 @@ namespace Robust.Client.GameObjects
         }
     }
 
-    internal struct RenderTreeRemoveSpriteMessage
+    internal class RenderTreeRemoveLightEvent : EntityEventArgs
     {
-        public RenderTreeRemoveSpriteMessage(SpriteComponent sprite, MapId map)
-        {
-            Sprite = sprite;
-            Map = map;
-        }
-
-        public SpriteComponent Sprite { get; }
-        public MapId Map { get; }
-    }
-
-    internal struct RenderTreeRemoveLightMessage
-    {
-        public RenderTreeRemoveLightMessage(PointLightComponent light, MapId map)
+        public RenderTreeRemoveLightEvent(PointLightComponent light, MapId map)
         {
             Light = light;
             Map = map;

Robust.Client/GameObjects/EntitySystems/SpriteSystem.cs

@@ -16,11 +16,17 @@ namespace Robust.Client.GameObjects
         [Dependency] private readonly IEyeManager _eyeManager = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
 
+        private RenderingTreeSystem _treeSystem = default!;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+            _treeSystem = Get<RenderingTreeSystem>();
+        }
+
         /// <inheritdoc />
         public override void FrameUpdate(float frameTime)
         {
-            var renderTreeSystem = EntitySystemManager.GetEntitySystem<RenderingTreeSystem>();
-
             // So we could calculate the correct size of the entities based on the contents of their sprite...
             // Or we can just assume that no entity is larger than 10x10 and get a stupid easy check.
             var pvsBounds = _eyeManager.GetWorldViewport().Enlarged(5);
@@ -33,18 +39,9 @@ namespace Robust.Client.GameObjects
 
             foreach (var gridId in _mapManager.FindGridIdsIntersecting(currentMap, pvsBounds, true))
             {
-                Box2 gridBounds;
+                var gridBounds = gridId == GridId.Invalid ? pvsBounds : pvsBounds.Translated(-_mapManager.GetGrid(gridId).WorldPosition);
 
-                if (gridId == GridId.Invalid)
-                {
-                    gridBounds = pvsBounds;
-                }
-                else
-                {
-                    gridBounds = pvsBounds.Translated(-_mapManager.GetGrid(gridId).WorldPosition);
-                }
-
-                var mapTree = renderTreeSystem.GetSpriteTreeForMap(currentMap, gridId);
+                var mapTree = _treeSystem.GetSpriteTreeForMap(currentMap, gridId);
 
                 mapTree.QueryAabb(ref frameTime, (ref float state, in SpriteComponent value) =>
                 {

Robust.Client/GameObjects/EntitySystems/UserInterfaceSystem.cs

@@ -0,0 +1,37 @@
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+
+namespace Robust.Client.GameObjects
+{
+    [UsedImplicitly]
+    public sealed class UserInterfaceSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeNetworkEvent<BoundUIWrapMessage>(MessageReceived);
+            SubscribeLocalEvent<ClientUserInterfaceComponent, ComponentShutdown>(OnUserInterfaceShutdown);
+        }
+
+        private void OnUserInterfaceShutdown(EntityUid uid, ClientUserInterfaceComponent component, ComponentShutdown args)
+        {
+            foreach (var bui in component.Interfaces)
+            {
+                bui.Dispose();
+            }
+        }
+
+        private void MessageReceived(BoundUIWrapMessage ev)
+        {
+            var cmp = ComponentManager.GetComponent<ClientUserInterfaceComponent>(ev.Entity);
+
+            cmp.MessageReceived(ev);
+        }
+
+        internal void Send(BoundUIWrapMessage msg)
+        {
+            RaiseNetworkEvent(msg);
+        }
+    }
+}

Robust.Client/GameObjects/PlayerMessages.cs

@@ -1,12 +1,15 @@
+using System;
 using Robust.Shared.GameObjects;
 
 namespace Robust.Client.GameObjects
 {
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
     public class PlayerAttachedMsg : ComponentMessage
     {
 
     }
 
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
     public class PlayerDetachedMsg : ComponentMessage
     {
 

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -1,3 +1,5 @@
+// ReSharper disable once RedundantUsingDirective
+// Used in EXCEPTION_TOLERANCE preprocessor
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
@@ -5,19 +7,18 @@ using System.Linq;
 using Robust.Client.GameObjects;
 using Robust.Client.Input;
 using Robust.Client.Map;
-using Robust.Shared.GameStates;
-using Robust.Shared.IoC;
-using Robust.Shared.Network.Messages;
 using Robust.Client.Player;
 using Robust.Client.Timing;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.Exceptions;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 using Robust.Shared.Input;
+using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Map;
 using Robust.Shared.Network;
+using Robust.Shared.Network.Messages;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -80,8 +81,8 @@ namespace Robust.Client.GameStates
         {
             _processor = new GameStateProcessor(_timing);
 
-            _network.RegisterNetMessage<MsgState>(MsgState.NAME, HandleStateMessage);
-            _network.RegisterNetMessage<MsgStateAck>(MsgStateAck.NAME);
+            _network.RegisterNetMessage<MsgState>(HandleStateMessage);
+            _network.RegisterNetMessage<MsgStateAck>();
             _client.RunLevelChanged += RunLevelChanged;
 
             _config.OnValueChanged(CVars.NetInterp, b => _processor.Interpolation = b, true);

Robust.Client/GameStates/NetEntityOverlay.cs

@@ -146,13 +146,12 @@ namespace Robust.Client.GameStates
         private void DrawWorld(in OverlayDrawArgs args)
         {
             bool pvsEnabled = _configurationManager.GetCVar<bool>("net.pvs");
-
             if(!pvsEnabled)
                 return;
 
-            float pvsSize = _configurationManager.GetCVar<float>("net.maxupdaterange");
+            float pvsRange = _configurationManager.GetCVar<float>("net.maxupdaterange");
             var pvsCenter = _eyeManager.CurrentEye.Position;
-            Box2 pvsBox = Box2.CenteredAround(pvsCenter.Position, new Vector2(pvsSize, pvsSize));
+            Box2 pvsBox = Box2.CenteredAround(pvsCenter.Position, new Vector2(pvsRange * 2, pvsRange * 2));
 
             var worldHandle = args.WorldHandle;
 

Robust.Client/Graphics/Clyde/Audio/Clyde.Audio.cs

@@ -44,8 +44,12 @@ namespace Robust.Client.Graphics.Clyde
 
         internal bool IsEfxSupported;
 
+        private ISawmill _openALSawmill = default!;
+
         private void _initializeAudio()
         {
+            _openALSawmill = Logger.GetSawmill("clyde.oal");
+
             _audioOpenDevice();
 
             // Create OpenAL context.
@@ -74,9 +78,9 @@ namespace Robust.Client.Graphics.Clyde
                 _alContextExtensions.Add(extension);
             }
 
-            Logger.DebugS("clyde.oal", "OpenAL Vendor: {0}", AL.Get(ALGetString.Vendor));
-            Logger.DebugS("clyde.oal", "OpenAL Renderer: {0}", AL.Get(ALGetString.Renderer));
-            Logger.DebugS("clyde.oal", "OpenAL Version: {0}", AL.Get(ALGetString.Version));
+            _openALSawmill.Debug("OpenAL Vendor: {0}", AL.Get(ALGetString.Vendor));
+            _openALSawmill.Debug("OpenAL Renderer: {0}", AL.Get(ALGetString.Renderer));
+            _openALSawmill.Debug("OpenAL Version: {0}", AL.Get(ALGetString.Version));
         }
 
         private void _audioOpenDevice()
@@ -89,7 +93,7 @@ namespace Robust.Client.Graphics.Clyde
                 _openALDevice = ALC.OpenDevice(preferredDevice);
                 if (_openALDevice == IntPtr.Zero)
                 {
-                    Logger.WarningS("clyde.oal", "Unable to open preferred audio device '{0}': {1}. Falling back default.",
+                    _openALSawmill.Warning("Unable to open preferred audio device '{0}': {1}. Falling back default.",
                         preferredDevice, ALC.GetError(ALDevice.Null));
 
                     _openALDevice = ALC.OpenDevice(null);
@@ -153,7 +157,7 @@ namespace Robust.Client.Graphics.Clyde
             // Clear out finalized audio sources.
             while (_sourceDisposeQueue.TryDequeue(out var handles))
             {
-                Logger.DebugS("clyde.oal", "Cleaning out source {0} which finalized in another thread.", handles.sourceHandle);
+                _openALSawmill.Debug("Cleaning out source {0} which finalized in another thread.", handles.sourceHandle);
                 if (IsEfxSupported) RemoveEfx(handles);
                 AL.DeleteSource(handles.sourceHandle);
                 _checkAlError();
@@ -163,7 +167,7 @@ namespace Robust.Client.Graphics.Clyde
             // Clear out finalized buffered audio sources.
             while (_bufferedSourceDisposeQueue.TryDequeue(out var handles))
             {
-                Logger.DebugS("clyde.oal", "Cleaning out buffered source {0} which finalized in another thread.", handles.sourceHandle);
+                _openALSawmill.Debug("Cleaning out buffered source {0} which finalized in another thread.", handles.sourceHandle);
                 if (IsEfxSupported) RemoveEfx(handles);
                 AL.DeleteSource(handles.sourceHandle);
                 _checkAlError();
@@ -211,24 +215,24 @@ namespace Robust.Client.Graphics.Clyde
             return audioSource;
         }
 
-        private static void _checkAlcError(ALDevice device,
+        private void _checkAlcError(ALDevice device,
             [CallerMemberName] string callerMember = "",
             [CallerLineNumber] int callerLineNumber = -1)
         {
             var error = ALC.GetError(device);
             if (error != AlcError.NoError)
             {
-                Logger.ErrorS("clyde.oal", "[{0}:{1}] ALC error: {2}", callerMember, callerLineNumber, error);
+                _openALSawmill.Error("[{0}:{1}] ALC error: {2}", callerMember, callerLineNumber, error);
             }
         }
 
-        private static void _checkAlError([CallerMemberName] string callerMember = "",
+        private void _checkAlError([CallerMemberName] string callerMember = "",
             [CallerLineNumber] int callerLineNumber = -1)
         {
             var error = AL.GetError();
             if (error != ALError.NoError)
             {
-                Logger.ErrorS("clyde.oal", "[{0}:{1}] AL error: {2}", callerMember, callerLineNumber, error);
+                _openALSawmill.Error("[{0}:{1}] AL error: {2}", callerMember, callerLineNumber, error);
             }
         }
 
@@ -330,6 +334,35 @@ namespace Robust.Client.Graphics.Clyde
             return new AudioStream(handle, length, wav.NumChannels, name);
         }
 
+        public AudioStream LoadAudioRaw(ReadOnlySpan<short> samples, int channels, int sampleRate, string? name = null)
+        {
+            var fmt = channels switch
+            {
+                1 => ALFormat.Mono16,
+                2 => ALFormat.Stereo16,
+                _ => throw new ArgumentOutOfRangeException(
+                    nameof(channels), "Only stereo and mono is currently supported")
+            };
+
+            var buffer = AL.GenBuffer();
+            _checkAlError();
+
+            unsafe
+            {
+                fixed (short* ptr = samples)
+                {
+                    AL.BufferData(buffer, fmt, (IntPtr) ptr, samples.Length * sizeof(short), sampleRate);
+                }
+            }
+
+            _checkAlError();
+
+            var handle = new ClydeHandle(_audioSampleBuffers.Count);
+            var length = TimeSpan.FromSeconds((double) samples.Length / channels / sampleRate);
+            _audioSampleBuffers.Add(new LoadedAudioSample(buffer));
+            return new AudioStream(handle, length, channels, name);
+        }
+
         private sealed class LoadedAudioSample
         {
             public readonly int BufferHandle;
@@ -381,14 +414,14 @@ namespace Robust.Client.Graphics.Clyde
             {
                 _checkDisposed();
                 AL.SourcePlay(SourceHandle);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void StopPlaying()
             {
                 _checkDisposed();
                 AL.SourceStop(SourceHandle);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public bool IsPlaying
@@ -407,14 +440,14 @@ namespace Robust.Client.Graphics.Clyde
                 {
                     _checkDisposed();
                     AL.GetSource(SourceHandle, ALSourceb.Looping, out var ret);
-                    _checkAlError();
+                    _master._checkAlError();
                     return ret;
                 }
                 set
                 {
                     _checkDisposed();
                     AL.Source(SourceHandle, ALSourceb.Looping, value);
-                    _checkAlError();
+                    _master._checkAlError();
                 }
             }
 
@@ -422,7 +455,7 @@ namespace Robust.Client.Graphics.Clyde
             {
                 _checkDisposed();
                 AL.Source(SourceHandle, ALSourceb.SourceRelative, true);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void SetVolume(float decibels)
@@ -436,7 +469,21 @@ namespace Robust.Client.Graphics.Clyde
                 }
                 _gain =  MathF.Pow(10, decibels / 10);
                 AL.Source(SourceHandle, ALSourcef.Gain, _gain * priorOcclusion);
-                _checkAlError();
+                _master._checkAlError();
+            }
+
+            public void SetVolumeDirect(float scale)
+            {
+                _checkDisposed();
+                var priorOcclusion = 1f;
+                if (!IsEfxSupported)
+                {
+                    AL.GetSource(SourceHandle, ALSourcef.Gain, out var priorGain);
+                    priorOcclusion = priorGain / _gain;
+                }
+                _gain = scale;
+                AL.Source(SourceHandle, ALSourcef.Gain, _gain * priorOcclusion);
+                _master._checkAlError();
             }
 
             public void SetOcclusion(float blocks)
@@ -453,7 +500,7 @@ namespace Robust.Client.Graphics.Clyde
                     gain *= gain * gain;
                     AL.Source(SourceHandle, ALSourcef.Gain, _gain * gain);
                 }
-                _checkAlError();
+                _master._checkAlError();
             }
 
             private void SetOcclusionEfx(float gain, float cutoff)
@@ -473,7 +520,7 @@ namespace Robust.Client.Graphics.Clyde
             {
                 _checkDisposed();
                 AL.Source(SourceHandle, ALSourcef.SecOffset, seconds);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public bool SetPosition(Vector2 position)
@@ -499,7 +546,7 @@ namespace Robust.Client.Graphics.Clyde
 #endif
 
                 AL.Source(SourceHandle, ALSource3f.Position, x, y, 0);
-                _checkAlError();
+                _master._checkAlError();
                 return true;
             }
 
@@ -526,14 +573,14 @@ namespace Robust.Client.Graphics.Clyde
 
                 AL.Source(SourceHandle, ALSource3f.Velocity, x, y, 0);
 
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void SetPitch(float pitch)
             {
                 _checkDisposed();
                 AL.Source(SourceHandle, ALSourcef.Pitch, pitch);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             ~AudioSource()
@@ -559,7 +606,7 @@ namespace Robust.Client.Graphics.Clyde
                     if (FilterHandle != 0) EFX.DeleteFilter(FilterHandle);
                     AL.DeleteSource(SourceHandle);
                     _master._audioSources.Remove(SourceHandle);
-                    _checkAlError();
+                    _master._checkAlError();
                 }
 
                 SourceHandle = -1;
@@ -609,7 +656,7 @@ namespace Robust.Client.Graphics.Clyde
                 _checkDisposed();
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.SourcePlay(stackalloc int[] {SourceHandle!.Value});
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void StopPlaying()
@@ -617,7 +664,7 @@ namespace Robust.Client.Graphics.Clyde
                 _checkDisposed();
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.SourceStop(SourceHandle!.Value);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public bool IsPlaying
@@ -643,7 +690,7 @@ namespace Robust.Client.Graphics.Clyde
                 _mono = false;
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.Source(SourceHandle!.Value, ALSourceb.SourceRelative, true);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void SetLooping()
@@ -662,7 +709,21 @@ namespace Robust.Client.Graphics.Clyde
                 }
                 _gain =  MathF.Pow(10, decibels / 10);
                 AL.Source(SourceHandle!.Value, ALSourcef.Gain, _gain * priorOcclusion);
-                _checkAlError();
+                _master._checkAlError();
+            }
+
+            public void SetVolumeDirect(float scale)
+            {
+                _checkDisposed();
+                var priorOcclusion = 1f;
+                if (!IsEfxSupported)
+                {
+                    AL.GetSource(SourceHandle!.Value, ALSourcef.Gain, out var priorGain);
+                    priorOcclusion = priorGain / _gain;
+                }
+                _gain = scale;
+                AL.Source(SourceHandle!.Value, ALSourcef.Gain, _gain * priorOcclusion);
+                _master._checkAlError();
             }
 
             public void SetOcclusion(float blocks)
@@ -680,7 +741,7 @@ namespace Robust.Client.Graphics.Clyde
                     AL.Source(SourceHandle!.Value, ALSourcef.Gain, gain * _gain);
                 }
 
-                _checkAlError();
+                _master._checkAlError();
             }
 
             private void SetOcclusionEfx(float gain, float cutoff)
@@ -700,7 +761,7 @@ namespace Robust.Client.Graphics.Clyde
                 _checkDisposed();
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.Source(SourceHandle!.Value, ALSourcef.SecOffset, seconds);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public bool SetPosition(Vector2 position)
@@ -717,7 +778,7 @@ namespace Robust.Client.Graphics.Clyde
                 _mono = true;
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.Source(SourceHandle!.Value, ALSource3f.Position, x, y, 0);
-                _checkAlError();
+                _master._checkAlError();
                 return true;
             }
 
@@ -744,7 +805,7 @@ namespace Robust.Client.Graphics.Clyde
 
                 AL.Source(SourceHandle!.Value, ALSource3f.Velocity, x, y, 0);
 
-                _checkAlError();
+                _master._checkAlError();
             }
 
             public void SetPitch(float pitch)
@@ -752,7 +813,7 @@ namespace Robust.Client.Graphics.Clyde
                 _checkDisposed();
                 // ReSharper disable once PossibleInvalidOperationException
                 AL.Source(SourceHandle!.Value, ALSourcef.Pitch, pitch);
-                _checkAlError();
+                _master._checkAlError();
             }
 
             ~BufferedAudioSource()
@@ -783,7 +844,7 @@ namespace Robust.Client.Graphics.Clyde
                     AL.DeleteSource(SourceHandle.Value);
                     AL.DeleteBuffers(BufferHandles);
                     _master._bufferedAudioSources.Remove(SourceHandle.Value);
-                    _checkAlError();
+                    _master._checkAlError();
                 }
 
                 SourceHandle = null;

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -59,7 +59,6 @@ namespace Robust.Client.Graphics.Clyde
         private bool _enableSoftShadows = true;
 
         private bool _checkGLErrors;
-        private bool _initialized;
 
         private Thread? _gameThread;
 
@@ -105,7 +104,6 @@ namespace Robust.Client.Graphics.Clyde
                 return false;
 
             _initializeAudio();
-            _initialized = true;
             return true;
         }
 

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -48,14 +48,14 @@ namespace Robust.Client.Graphics.Clyde
         public IClydeDebugInfo DebugInfo { get; } = new DummyDebugInfo();
         public IClydeDebugStats DebugStats { get; } = new DummyDebugStats();
 
-        public event Action<TextEventArgs>? TextEntered;
-        public event Action<MouseMoveEventArgs>? MouseMove;
-        public event Action<MouseEnterLeaveEventArgs>? MouseEnterLeave;
-        public event Action<KeyEventArgs>? KeyUp;
-        public event Action<KeyEventArgs>? KeyDown;
-        public event Action<MouseWheelEventArgs>? MouseWheel;
-        public event Action<WindowClosedEventArgs>? CloseWindow;
-        public event Action<WindowDestroyedEventArgs>? DestroyWindow;
+        public event Action<TextEventArgs>? TextEntered { add { } remove { } }
+        public event Action<MouseMoveEventArgs>? MouseMove { add { } remove { } }
+        public event Action<MouseEnterLeaveEventArgs>? MouseEnterLeave { add { } remove { } }
+        public event Action<KeyEventArgs>? KeyUp { add { } remove { } }
+        public event Action<KeyEventArgs>? KeyDown { add { } remove { } }
+        public event Action<MouseWheelEventArgs>? MouseWheel { add { } remove { } }
+        public event Action<WindowClosedEventArgs>? CloseWindow { add { } remove { } }
+        public event Action<WindowDestroyedEventArgs>? DestroyWindow { add { } remove { } }
 
         public Texture GetStockTexture(ClydeStockTexture stockTexture)
         {
@@ -248,6 +248,12 @@ namespace Robust.Client.Graphics.Clyde
             return new(default, default, 1, name);
         }
 
+        public AudioStream LoadAudioRaw(ReadOnlySpan<short> samples, int channels, int sampleRate, string? name = null)
+        {
+            // TODO: Might wanna actually load this so the length gets reported correctly.
+            return new(default, default, channels, name);
+        }
+
         public IClydeAudioSource CreateAudioSource(AudioStream stream)
         {
             return DummyAudioSource.Instance;
@@ -323,6 +329,11 @@ namespace Robust.Client.Graphics.Clyde
                 // Nada.
             }
 
+            public void SetVolumeDirect(float scale)
+            {
+                // Nada.
+            }
+
             public void SetOcclusion(float blocks)
             {
                 // Nada.
@@ -594,7 +605,7 @@ namespace Robust.Client.Graphics.Clyde
             public bool IsVisible { get; set; } = true;
             public Vector2 ContentScale => Vector2.One;
             public bool DisposeOnClose { get; set; }
-            public event Action<WindowClosedEventArgs>? Closed;
+            public event Action<WindowClosedEventArgs>? Closed { add { } remove { } }
 
             public void MaximizeOnMonitor(IClydeMonitor monitor)
             {

Robust.Client/Graphics/Clyde/Windowing/Glfw.Cursors.cs

@@ -71,7 +71,7 @@ namespace Robust.Client.Graphics.Clyde
                 var impl = (CursorImpl) cursor;
                 DebugTools.Assert(impl.Owner == this);
 
-                if (impl.Id == null)
+                if (impl.Id == default)
                 {
                     throw new ObjectDisposedException(nameof(cursor));
                 }

Robust.Client/Graphics/IClydeAudio.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System;
+using System.IO;
 using Robust.Client.Audio;
 
 namespace Robust.Client.Graphics
@@ -8,6 +9,7 @@ namespace Robust.Client.Graphics
         // AUDIO SYSTEM DOWN BELOW.
         AudioStream LoadAudioOggVorbis(Stream stream, string? name = null);
         AudioStream LoadAudioWav(Stream stream, string? name = null);
+        AudioStream LoadAudioRaw(ReadOnlySpan<short> samples, int channels, int sampleRate, string? name = null);
 
         void SetMasterVolume(float newVolume);
 

Robust.Client/Graphics/IClydeAudioSource.cs

@@ -18,6 +18,7 @@ namespace Robust.Client.Graphics
         void SetPitch(float pitch);
         void SetGlobal();
         void SetVolume(float decibels);
+        void SetVolumeDirect(float decibels);
         void SetOcclusion(float blocks);
         void SetPlaybackPosition(float seconds);
         void SetVelocity(Vector2 velocity);

Robust.Client/Input/InputManager.cs

@@ -334,6 +334,7 @@ namespace Robust.Client.Input
         {
             // christ this crap *is* re-entrant thanks to PlacementManager and
             // I honestly have no idea what the best solution here is.
+            // note from the future: context switches won't cause re-entrancy anymore because InputContextContainer defers context switches
             DebugTools.Assert(!_currentlyFindingViewport, "Re-entrant key events??");
 
             try
@@ -341,6 +342,8 @@ namespace Robust.Client.Input
                 // This is terrible but anyways.
                 // This flag keeps track of "did a viewport fire the key up for us" so we know we don't do it again.
                 _currentlyFindingViewport = true;
+                // And this stops context switches from causing crashes
+                Contexts.DeferringEnabled = true;
 
                 binding.State = state;
 
@@ -361,12 +364,14 @@ namespace Robust.Client.Input
             finally
             {
                 _currentlyFindingViewport = false;
+                Contexts.DeferringEnabled = false;
             }
         }
 
         public void ViewportKeyEvent(Control? viewport, BoundKeyEventArgs eventArgs)
         {
             _currentlyFindingViewport = false;
+            Contexts.DeferringEnabled = false;
 
             var cmd = GetInputCommand(eventArgs.Function);
             // TODO: Allow input commands to still get forwarded to server if necessary.

Robust.Client/Physics/DebugPhysicsIslandSystem.cs

@@ -52,7 +52,7 @@ namespace Robust.Client.Physics
         public override void Shutdown()
         {
             base.Shutdown();
-            UnsubscribeLocalEvent<IslandSolveMessage>();
+
             IoCManager.Resolve<IOverlayManager>().RemoveOverlay(typeof(PhysicsIslandOverlay));
         }
 

Robust.Client/Placement/PlacementManager.cs

@@ -156,7 +156,7 @@ namespace Robust.Client.Placement
         {
             _drawingShader = _prototypeManager.Index<ShaderPrototype>("unshaded").Instance();
 
-            NetworkManager.RegisterNetMessage<MsgPlacement>(MsgPlacement.NAME, HandlePlacementMessage);
+            NetworkManager.RegisterNetMessage<MsgPlacement>(HandlePlacementMessage);
 
             _modeDictionary.Clear();
             foreach (var type in ReflectionManager.GetAllChildren<PlacementMode>())

Robust.Client/Player/IPlayerManager.cs

@@ -2,13 +2,14 @@ using System;
 using System.Collections.Generic;
 using Robust.Shared.GameStates;
 using Robust.Shared.Network;
+using Robust.Shared.Players;
 
 namespace Robust.Client.Player
 {
     public interface IPlayerManager : Shared.Players.ISharedPlayerManager
     {
-        new IEnumerable<IPlayerSession> Sessions { get; }
-        IReadOnlyDictionary<NetUserId, IPlayerSession> SessionsDict { get; }
+        new IEnumerable<ICommonSession> Sessions { get; }
+        IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict { get; }
 
         LocalPlayer? LocalPlayer { get; }
 

Robust.Client/Player/IPlayerSession.cs

@@ -1,11 +0,0 @@
-using System;
-using Robust.Shared.Players;
-
-namespace Robust.Client.Player
-{
-    /// <summary>
-    /// Client side session of a player.
-    /// </summary>
-    [Obsolete("Use the base " + nameof(ICommonSession))]
-    public interface IPlayerSession : ICommonSession { }
-}

Robust.Client/Player/LocalPlayer.cs

@@ -4,6 +4,7 @@ using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Network;
+using Robust.Shared.Players;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Player
@@ -36,7 +37,7 @@ namespace Robust.Client.Player
         ///     Session of the local client.
         /// </summary>
         [ViewVariables]
-        public IPlayerSession Session => InternalSession;
+        public ICommonSession Session => InternalSession;
 
         internal PlayerSession InternalSession { get; set; } = default!;
 

Robust.Client/Player/PlayerManager.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
@@ -28,7 +27,7 @@ namespace Robust.Client.Player
         /// <summary>
         ///     Active sessions of connected clients to the server.
         /// </summary>
-        private readonly Dictionary<NetUserId, IPlayerSession> _sessions = new();
+        private readonly Dictionary<NetUserId, ICommonSession> _sessions = new();
 
         /// <inheritdoc />
         public IEnumerable<ICommonSession> NetworkedSessions
@@ -69,10 +68,10 @@ namespace Robust.Client.Player
 
         /// <inheritdoc />
         [ViewVariables]
-        IEnumerable<IPlayerSession> IPlayerManager.Sessions => _sessions.Values;
+        IEnumerable<ICommonSession> IPlayerManager.Sessions => _sessions.Values;
 
         /// <inheritdoc />
-        public IReadOnlyDictionary<NetUserId, IPlayerSession> SessionsDict => _sessions;
+        public IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict => _sessions;
 
         /// <inheritdoc />
         public event EventHandler? PlayerListUpdated;
@@ -82,8 +81,8 @@ namespace Robust.Client.Player
         {
             _client.RunLevelChanged += OnRunLevelChanged;
 
-            _network.RegisterNetMessage<MsgPlayerListReq>(MsgPlayerListReq.NAME);
-            _network.RegisterNetMessage<MsgPlayerList>(MsgPlayerList.NAME, HandlePlayerList);
+            _network.RegisterNetMessage<MsgPlayerListReq>();
+            _network.RegisterNetMessage<MsgPlayerList>(HandlePlayerList);
         }
 
         /// <inheritdoc />

Robust.Client/Player/PlayerSession.cs

@@ -5,7 +5,7 @@ using Robust.Shared.Players;
 
 namespace Robust.Client.Player
 {
-    internal sealed class PlayerSession : IPlayerSession
+    internal sealed class PlayerSession : ICommonSession
     {
         internal SessionStatus Status { get; set; } = SessionStatus.Connecting;
 

Robust.Client/Prototypes/ClientPrototypeManager.cs

@@ -30,7 +30,7 @@ namespace Robust.Client.Prototypes
         {
             base.Initialize();
 
-            _netManager.RegisterNetMessage<MsgReloadPrototypes>(MsgReloadPrototypes.NAME, accept: NetMessageAccept.Server);
+            _netManager.RegisterNetMessage<MsgReloadPrototypes>(accept: NetMessageAccept.Server);
 
             _clyde.OnWindowFocused += WindowFocusedChanged;
 

Robust.Client/UserInterface/Controls/Tree.cs

@@ -20,7 +20,7 @@ namespace Robust.Client.UserInterface.Controls
 
         public bool HideRoot { get; set; }
 
-        public Item? Root => _root;
+        public Item? TreeRoot => _root;
 
         public Item? Selected => _selectedIndex == null ? null : _itemList[_selectedIndex.Value];
 

Robust.Client/UserInterface/CustomControls/DebugConsole.xaml.cs

@@ -288,7 +288,7 @@ namespace Robust.Client.UserInterface.CustomControls
                 }
                 catch (Exception e)
                 {
-                    sawmill.Warning("Failed to load debug console history due to exception!\n{e}");
+                    sawmill.Warning($"Failed to load debug console history due to exception!\n{e}");
                     return null;
                 }
                 finally

Robust.Client/UserInterface/CustomControls/DebugInputPanel.cs

@@ -36,7 +36,8 @@ namespace Robust.Client.UserInterface.CustomControls
                 return;
             }
 
-            _label.Text = string.Join("\n", _inputManager.DownKeyFunctions);
+            var functionsText = string.Join("\n", _inputManager.DownKeyFunctions);
+            _label.Text = $"Context: {_inputManager.Contexts.ActiveContext.Name}\n{functionsText}";
         }
     }
 }

Robust.Client/UserInterface/CustomControls/SS14Window.xaml.cs

@@ -96,7 +96,7 @@ namespace Robust.Client.UserInterface.CustomControls
             var (spaceX, spaceY) = Parent!.Size;
             if (Position.Y > spaceY)
             {
-                LayoutContainer.SetPosition(this, (Position.X, spaceY - HEADER_SIZE_Y));
+                LayoutContainer.SetPosition(this, (Position.X, spaceY + HEADER_SIZE_Y));
             }
 
             if (Position.X > spaceX)
@@ -104,6 +104,16 @@ namespace Robust.Client.UserInterface.CustomControls
                 // 50 is arbitrary here. As long as it's bumped back into view.
                 LayoutContainer.SetPosition(this, (spaceX - 50, Position.Y));
             }
+
+            if (Position.Y < 0)
+            {
+                LayoutContainer.SetPosition(this, (Position.X, 0));
+            }
+
+            if (Position.X < 0)
+            {
+                LayoutContainer.SetPosition(this, (0, Position.Y));
+            }
         }
 
         protected override DragMode GetDragModeFor(Vector2 relativeMousePos)

Robust.Client/UserInterface/UserInterfaceManager.cs

@@ -25,8 +25,6 @@ namespace Robust.Client.UserInterface
     {
         [Dependency] private readonly IInputManager _inputManager = default!;
         [Dependency] private readonly IClydeInternal _clyde = default!;
-        [Dependency] private readonly IClientConsoleHost _consoleHost = default!;
-        [Dependency] private readonly IResourceManager _resourceManager = default!;
         [Dependency] private readonly IGameTiming _gameTiming = default!;
         [Dependency] private readonly IPlayerManager _playerManager = default!;
         [Dependency] private readonly IEyeManager _eyeManager = default!;

Robust.Client/ViewVariables/ViewVariablesManager.cs

@@ -16,7 +16,7 @@ using Robust.Shared.Network.Messages;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
-using NumberType = Robust.Client.ViewVariables.Editors.VVPropEditorNumeric.NumberType;
+using static Robust.Client.ViewVariables.Editors.VVPropEditorNumeric;
 
 namespace Robust.Client.ViewVariables
 {
@@ -43,17 +43,13 @@ namespace Robust.Client.ViewVariables
 
         public void Initialize()
         {
-            _netManager.RegisterNetMessage<MsgViewVariablesOpenSession>(MsgViewVariablesOpenSession.NAME,
-                _netMessageOpenSession);
-            _netManager.RegisterNetMessage<MsgViewVariablesRemoteData>(MsgViewVariablesRemoteData.NAME,
-                _netMessageRemoteData);
-            _netManager.RegisterNetMessage<MsgViewVariablesCloseSession>(MsgViewVariablesCloseSession.NAME,
-                _netMessageCloseSession);
-            _netManager.RegisterNetMessage<MsgViewVariablesDenySession>(MsgViewVariablesDenySession.NAME,
-                _netMessageDenySession);
-            _netManager.RegisterNetMessage<MsgViewVariablesModifyRemote>(MsgViewVariablesModifyRemote.NAME);
-            _netManager.RegisterNetMessage<MsgViewVariablesReqSession>(MsgViewVariablesReqSession.NAME);
-            _netManager.RegisterNetMessage<MsgViewVariablesReqData>(MsgViewVariablesReqData.NAME);
+            _netManager.RegisterNetMessage<MsgViewVariablesOpenSession>(_netMessageOpenSession);
+            _netManager.RegisterNetMessage<MsgViewVariablesRemoteData>(_netMessageRemoteData);
+            _netManager.RegisterNetMessage<MsgViewVariablesCloseSession>(_netMessageCloseSession);
+            _netManager.RegisterNetMessage<MsgViewVariablesDenySession>(_netMessageDenySession);
+            _netManager.RegisterNetMessage<MsgViewVariablesModifyRemote>();
+            _netManager.RegisterNetMessage<MsgViewVariablesReqSession>();
+            _netManager.RegisterNetMessage<MsgViewVariablesReqData>();
         }
 
         public VVPropEditor PropertyFor(Type? type)

Robust.Server/BaseServer.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Diagnostics;
 using System.IO;
 using System.Runtime;
@@ -217,6 +217,26 @@ namespace Robust.Server
                 _log.RootSawmill.AddHandler(_logHandler!);
             }
 
+            if (_commandLineArgs != null)
+            {
+                foreach (var (sawmill, level) in _commandLineArgs.LogLevels)
+                {
+                    LogLevel? logLevel;
+                    if (level == "null")
+                        logLevel = null;
+                    else
+                    {
+                        if (!Enum.TryParse<LogLevel>(level, out var result))
+                        {
+                            System.Console.WriteLine($"LogLevel {level} does not exist!");
+                            continue;
+                        }
+                        logLevel = result;
+                    }
+                    _log.GetSawmill(sawmill).Level = logLevel;
+                }
+            }
+
             SelfLog.Enable(s => { System.Console.WriteLine("SERILOG ERROR: {0}", s); });
 
             if (!SetupLoki())
@@ -306,7 +326,6 @@ namespace Robust.Server
             // Call Init in game assemblies.
             _modLoader.BroadcastRunLevel(ModRunLevel.Init);
             _entityManager.Initialize();
-            IoCManager.Resolve<IEntityLookup>().Initialize();
 
             IoCManager.Resolve<ISerializationManager>().Initialize();
 
@@ -319,6 +338,7 @@ namespace Robust.Server
 
             IoCManager.Resolve<IServerConsoleHost>().Initialize();
             _entityManager.Startup();
+            IoCManager.Resolve<IEntityLookup>().Startup();
             _stateManager.Initialize();
             _scriptHost.Initialize();
 
@@ -330,6 +350,7 @@ namespace Robust.Server
 
             _watchdogApi.Initialize();
 
+            AddFinalStringsToSerializer();
             _stringSerializer.LockStrings();
 
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) && _config.GetCVar(CVars.SysWinTickPeriod) >= 0)
@@ -342,6 +363,16 @@ namespace Robust.Server
             return false;
         }
 
+        private void AddFinalStringsToSerializer()
+        {
+            var factory = IoCManager.Resolve<IComponentFactory>();
+            foreach (var regType in factory.AllRegisteredTypes)
+            {
+                var reg = factory.GetRegistration(regType);
+                _stringSerializer.AddString(reg.Name);
+            }
+        }
+
         private bool SetupLoki()
         {
             var enabled = _config.GetCVar(CVars.LokiEnabled);

Robust.Server/CommandLineArgs.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using Robust.Shared;
 using Robust.Shared.Utility;
@@ -12,6 +12,7 @@ namespace Robust.Server
         public string? ConfigFile { get; }
         public string? DataDir { get; }
         public IReadOnlyCollection<(string key, string value)> CVars { get; }
+        public IReadOnlyCollection<(string key, string value)> LogLevels { get; }
 
         // Manual parser because C# has no good command line parsing libraries. Also dependencies bad.
         // Also I don't like spending 100ms parsing command line args. Do you?
@@ -21,6 +22,7 @@ namespace Robust.Server
             string? configFile = null;
             string? dataDir = null;
             var cvars = new List<(string, string)>();
+            var logLevels = new List<(string, string)>();
             var mountOptions = new MountOptions();
 
             using var enumerator = args.GetEnumerator();
@@ -93,13 +95,33 @@ namespace Robust.Server
 
                     mountOptions.DirMounts.Add(enumerator.Current);
                 }
+                else if (arg == "--loglevel")
+                {
+                    if (!enumerator.MoveNext())
+                    {
+                        C.WriteLine("Missing loglevel sawmill.");
+                        return false;
+                    }
+
+                    var loglevel = enumerator.Current;
+                    DebugTools.AssertNotNull(loglevel);
+                    var pos = loglevel.IndexOf('=');
+
+                    if (pos == -1)
+                    {
+                        C.WriteLine("Expected = in loglevel.");
+                        return false;
+                    }
+
+                    logLevels.Add((loglevel[..pos], loglevel[(pos + 1)..]));
+                }
                 else
                 {
                     C.WriteLine("Unknown argument: {0}", arg);
                 }
             }
 
-            parsed = new CommandLineArgs(configFile, dataDir, cvars, mountOptions);
+            parsed = new CommandLineArgs(configFile, dataDir, cvars, logLevels, mountOptions);
             return true;
         }
 
@@ -110,17 +132,19 @@ Options:
   --config-file     Path to the config file to read from.
   --data-dir        Path to the data directory to read/write from/to.
   --cvar            Specifies an additional cvar overriding the config file. Syntax is <key>=<value>
+  --loglevel        Specifies an additional sawmill log level overriding the default values. Syntax is <key>=<value>
   --mount-dir       Resource directory to mount.
   --mount-zip       Resource zip to mount.
   --help            Display this help text and exit.
 ");
         }
 
-        private CommandLineArgs(string? configFile, string? dataDir, IReadOnlyCollection<(string, string)> cVars, MountOptions mountOptions)
+        private CommandLineArgs(string? configFile, string? dataDir, IReadOnlyCollection<(string, string)> cVars, IReadOnlyCollection<(string, string)> logLevels, MountOptions mountOptions)
         {
             ConfigFile = configFile;
             DataDir = dataDir;
             CVars = cVars;
+            LogLevels = logLevels;
             MountOptions = mountOptions;
         }
     }

Robust.Server/Console/Commands/PlayerCommands.cs

@@ -57,9 +57,8 @@ namespace Robust.Server.Console.Commands
             else
             {
                 var mapEnt = mapMgr.GetMapEntity(mapId);
-
-                transform.AttachParent(mapEnt);
                 transform.WorldPosition = position;
+                transform.AttachParent(mapEnt);
             }
 
             shell.WriteLine($"Teleported {player} to {mapId}:{posX},{posY}.");

Robust.Server/Console/ServerConsoleHost.cs

@@ -62,15 +62,14 @@ namespace Robust.Server.Console
                 var sudoShell = new SudoShell(this, localShell, shell);
                 ExecuteInShell(sudoShell, argStr.Substring("sudo ".Length));
             });
-            
+
             LoadConsoleCommands();
 
             // setup networking with clients
-            NetManager.RegisterNetMessage<MsgConCmd>(MsgConCmd.NAME, ProcessCommand);
-            NetManager.RegisterNetMessage<MsgConCmdAck>(MsgConCmdAck.NAME);
+            NetManager.RegisterNetMessage<MsgConCmd>(ProcessCommand);
+            NetManager.RegisterNetMessage<MsgConCmdAck>();
 
-            NetManager.RegisterNetMessage<MsgConCmdReg>(MsgConCmdReg.NAME,
-                message => HandleRegistrationRequest(message.MsgChannel));
+            NetManager.RegisterNetMessage<MsgConCmdReg>(message => HandleRegistrationRequest(message.MsgChannel));
         }
 
         private void ExecuteInShell(IConsoleShell shell, string command)

Robust.Server/Debugging/DebugDrawingManager.cs

@@ -14,7 +14,7 @@ namespace Robust.Server.Debugging
 
         public void Initialize()
         {
-            _net.RegisterNetMessage<MsgRay>(MsgRay.NAME);
+            _net.RegisterNetMessage<MsgRay>();
             // TODO _physics.DebugDrawRay += data => PhysicsOnDebugDrawRay(data);
         }
 

Robust.Server/GameObjects/Components/Actor/ActorComponent.cs

@@ -0,0 +1,45 @@
+using System;
+using Robust.Server.Player;
+using Robust.Shared.GameObjects;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Server.GameObjects
+{
+    public class ActorComponent : Component
+    {
+        public override string Name => "Actor";
+
+        [ViewVariables]
+        public IPlayerSession PlayerSession { get; internal set; } = default!;
+    }
+
+    /// <summary>
+    ///     Raised on an entity whenever a player attaches to this entity.
+    /// </summary>
+    [Serializable]
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
+    public class PlayerAttachedMsg : ComponentMessage
+    {
+        public IPlayerSession NewPlayer { get; }
+
+        public PlayerAttachedMsg(IPlayerSession newPlayer)
+        {
+            NewPlayer = newPlayer;
+        }
+    }
+
+    /// <summary>
+    ///     Raised on an entity whenever a player detaches from this entity.
+    /// </summary>
+    [Serializable]
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
+    public class PlayerDetachedMsg : ComponentMessage
+    {
+        public IPlayerSession OldPlayer { get; }
+
+        public PlayerDetachedMsg(IPlayerSession oldPlayer)
+        {
+            OldPlayer = oldPlayer;
+        }
+    }
+}

Robust.Server/GameObjects/Components/Actor/BasicActorComponent.cs

@@ -1,75 +0,0 @@
-using System;
-using Robust.Server.Player;
-using Robust.Shared.GameObjects;
-using Robust.Shared.ViewVariables;
-
-namespace Robust.Server.GameObjects
-{
-    public class BasicActorComponent : Component, IActorComponent
-    {
-        public override string Name => "BasicActor";
-
-        [ViewVariables] public IPlayerSession playerSession { get; internal set; } = default!;
-
-        /// <inheritdoc />
-        protected override void Shutdown()
-        {
-            base.Shutdown();
-            
-            // Warning: careful here, Detach removes this component, make sure this is after the base shutdown
-            // to prevent infinite recursion
-            // ReSharper disable once ConstantConditionalAccessQualifier
-            playerSession?.DetachFromEntity();
-        }
-    }
-
-    /// <summary>
-    ///     Raised on an entity whenever a player attaches to this entity.
-    /// </summary>
-    [Serializable]
-    public class PlayerAttachedMsg : ComponentMessage
-    {
-        public IPlayerSession NewPlayer { get; }
-
-        public PlayerAttachedMsg(IPlayerSession newPlayer)
-        {
-            NewPlayer = newPlayer;
-        }
-    }
-
-    /// <summary>
-    ///     Raised on an entity whenever a player detaches from this entity.
-    /// </summary>
-    [Serializable]
-    public class PlayerDetachedMsg : ComponentMessage
-    {
-        public IPlayerSession OldPlayer { get; }
-
-        public PlayerDetachedMsg(IPlayerSession oldPlayer)
-        {
-            OldPlayer = oldPlayer;
-        }
-    }
-
-    public class PlayerAttachSystemMessage : EntityEventArgs
-    {
-        public PlayerAttachSystemMessage(IEntity entity, IPlayerSession newPlayer)
-        {
-            Entity = entity;
-            NewPlayer = newPlayer;
-        }
-
-        public IEntity Entity { get; }
-        public IPlayerSession NewPlayer { get; }
-    }
-
-    public class PlayerDetachedSystemMessage : EntityEventArgs
-    {
-        public PlayerDetachedSystemMessage(IEntity entity)
-        {
-            Entity = entity;
-        }
-
-        public IEntity Entity { get; }
-    }
-}

Robust.Server/GameObjects/Components/Actor/IActorComponent.cs

@@ -1,10 +0,0 @@
-using Robust.Server.Player;
-using Robust.Shared.GameObjects;
-
-namespace Robust.Server.GameObjects
-{
-    public interface IActorComponent : IComponent
-    {
-        IPlayerSession playerSession { get; }
-    }
-}

Robust.Server/GameObjects/Components/Appearance/AppearanceComponent.cs

@@ -7,6 +7,7 @@ using Robust.Shared.Players;
 
 namespace Robust.Server.GameObjects
 {
+    [ComponentReference(typeof(SharedAppearanceComponent))]
     public sealed class AppearanceComponent : SharedAppearanceComponent
     {
         [ViewVariables]

Robust.Server/GameObjects/Components/Eye/EyeComponent.cs

@@ -8,6 +8,7 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.GameObjects
 {
+    [ComponentReference(typeof(SharedEyeComponent))]
     public class EyeComponent : SharedEyeComponent
     {
         [DataField("drawFov")]

Robust.Server/GameObjects/Components/Renderable/SpriteComponent.cs

@@ -14,6 +14,8 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.GameObjects
 {
+    [ComponentReference(typeof(SharedSpriteComponent))]
+    [ComponentReference(typeof(ISpriteRenderableComponent))]
     public class SpriteComponent : SharedSpriteComponent, ISpriteRenderableComponent, ISerializationHooks
     {
         const string LayerSerializationCache = "spritelayersrv";

Robust.Server/GameObjects/Components/UserInterface/ServerUserInterfaceComponent.cs

@@ -7,8 +7,6 @@ using Robust.Server.Player;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Log;
-using Robust.Shared.Network;
-using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Serialization.Manager.Attributes;
 
@@ -20,6 +18,7 @@ namespace Robust.Server.GameObjects
     /// </summary>
     /// <seealso cref="BoundUserInterface"/>
     [PublicAPI]
+    [ComponentReference(typeof(SharedUserInterfaceComponent))]
     public sealed class ServerUserInterfaceComponent : SharedUserInterfaceComponent, ISerializationHooks
     {
         private readonly Dictionary<object, BoundUserInterface> _interfaces =
@@ -48,7 +47,8 @@ namespace Robust.Server.GameObjects
             return _interfaces[uiKey];
         }
 
-        public bool TryGetBoundUserInterface(object uiKey, [NotNullWhen(true)] out BoundUserInterface? boundUserInterface)
+        public bool TryGetBoundUserInterface(object uiKey,
+            [NotNullWhen(true)] out BoundUserInterface? boundUserInterface)
         {
             return _interfaces.TryGetValue(uiKey, out boundUserInterface);
         }
@@ -67,32 +67,20 @@ namespace Robust.Server.GameObjects
 
         internal void SendToSession(IPlayerSession session, BoundUserInterfaceMessage message, object uiKey)
         {
-            SendNetworkMessage(new BoundInterfaceMessageWrapMessage(message, uiKey), session.ConnectedClient);
+            EntitySystem.Get<UserInterfaceSystem>()
+                .SendTo(session, new BoundUIWrapMessage(Owner.Uid, message, uiKey));
         }
 
-        public override void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel,
-            ICommonSession? session = null)
+        internal void ReceiveMessage(IPlayerSession session, BoundUIWrapMessage msg)
         {
-            base.HandleNetworkMessage(message, netChannel, session);
-
-            switch (message)
+            if (!_interfaces.TryGetValue(msg.UiKey, out var @interface))
             {
-                case BoundInterfaceMessageWrapMessage wrapped:
-                    if (session == null)
-                    {
-                        throw new ArgumentNullException(nameof(session));
-                    }
-
-                    if (!_interfaces.TryGetValue(wrapped.UiKey, out var @interface))
-                    {
-                        Logger.DebugS("go.comp.ui", "Got BoundInterfaceMessageWrapMessage for unknown UI key: {0}",
-                            wrapped.UiKey);
-                        return;
-                    }
-
-                    @interface.ReceiveMessage(wrapped.Message, (IPlayerSession)session);
-                    break;
+                Logger.DebugS("go.comp.ui", "Got BoundInterfaceMessageWrapMessage for unknown UI key: {0}",
+                    msg.UiKey);
+                return;
             }
+
+            @interface.ReceiveMessage(msg.Message, session);
         }
     }
 
@@ -153,6 +141,7 @@ namespace Robust.Server.GameObjects
             {
                 _playerStateOverrides[session] = state;
             }
+
             _stateDirty = true;
         }
 
@@ -178,7 +167,6 @@ namespace Robust.Server.GameObjects
         }
 
 
-
         /// <summary>
         ///     Opens this interface for a specific client.
         /// </summary>

Robust.Server/GameObjects/EntitySystems/ActorSystem.cs

@@ -0,0 +1,173 @@
+using System;
+using JetBrains.Annotations;
+using Robust.Server.Player;
+using Robust.Shared.GameObjects;
+
+namespace Robust.Server.GameObjects
+{
+    /// <summary>
+    ///     System that handles players being attached/detached from entities.
+    /// </summary>
+    [UsedImplicitly]
+    public class ActorSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<AttachPlayerEvent>(OnActorPlayerAttach);
+            SubscribeLocalEvent<ActorComponent, DetachPlayerEvent>(OnActorPlayerDetach);
+            SubscribeLocalEvent<ActorComponent, ComponentShutdown>(OnActorShutdown);
+        }
+
+        private void OnActorPlayerAttach(AttachPlayerEvent args)
+        {
+            // Cannot attach to a deleted entity.
+            if (args.Entity.Deleted)
+            {
+                args.Result = false;
+                return;
+            }
+
+            var uid = args.Entity.Uid;
+
+            // Check if there was a player attached to the entity already...
+            if (ComponentManager.TryGetComponent(uid, out ActorComponent actor))
+            {
+                // If we're not forcing the attach, this fails.
+                if (!args.Force)
+                {
+                    args.Result = false;
+                    return;
+                }
+
+                // Set the event's force-kicked session before detaching it.
+                args.ForceKicked = actor.PlayerSession;
+
+                // This detach cannot fail, as a player is attached to this entity.
+                // It's important to note that detaching the player removes the component.
+                RaiseLocalEvent(uid, new DetachPlayerEvent());
+            }
+
+            // We add the actor component.
+            actor = ComponentManager.AddComponent<ActorComponent>(args.Entity);
+            actor.PlayerSession = args.Player;
+            args.Player.SetAttachedEntity(args.Entity);
+            args.Result = true;
+
+            // TODO: Remove component message.
+            args.Entity.SendMessage(actor, new PlayerAttachedMsg(args.Player));
+
+            // The player is fully attached now, raise an event!
+            RaiseLocalEvent(uid, new PlayerAttachedEvent(args.Entity, args.Player));
+        }
+
+        private void OnActorPlayerDetach(EntityUid uid, ActorComponent component, DetachPlayerEvent args)
+        {
+            // Removing the component will call shutdown, and our subscription will handle the rest of the detach logic.
+            ComponentManager.RemoveComponent<ActorComponent>(uid);
+            args.Result = true;
+        }
+
+        private void OnActorShutdown(EntityUid uid, ActorComponent component, ComponentShutdown args)
+        {
+            component.PlayerSession.SetAttachedEntity(null);
+
+            var entity = EntityManager.GetEntity(uid);
+
+            // TODO: Remove component message.
+            entity.SendMessage(component, new PlayerDetachedMsg(component.PlayerSession));
+
+            // The player is fully detached now that the component has shut down.
+            RaiseLocalEvent(uid, new PlayerDetachedEvent(entity, component.PlayerSession));
+        }
+    }
+
+    /// <summary>
+    ///     Raise this broadcast event to attach a player to an entity, optionally detaching the player attached to it.
+    /// </summary>
+    public class AttachPlayerEvent : EntityEventArgs
+    {
+        /// <summary>
+        ///     Player to attach to the entity.
+        ///     Input parameter.
+        /// </summary>
+        public IPlayerSession Player { get; }
+
+        /// <summary>
+        ///     Entity to attach the player to.
+        ///     Input parameter.
+        /// </summary>
+        public IEntity Entity { get; }
+
+        /// <summary>
+        ///     Whether to force-attach the player,
+        ///     detaching any players attached to it if any.
+        ///     Input parameter.
+        /// </summary>
+        public bool Force { get; }
+
+        /// <summary>
+        ///     If the attach was forced and there was a player attached to the entity before, this will be it.
+        ///     Output parameter.
+        /// </summary>
+        public IPlayerSession? ForceKicked { get; set; }
+
+        /// <summary>
+        ///     Whether the player was attached correctly.
+        ///     False if not forcing and the entity already had a player attached to it.
+        ///     Output parameter.
+        /// </summary>
+        public bool Result { get; set; } = false;
+
+        public AttachPlayerEvent(IEntity entity, IPlayerSession player, bool force = false)
+        {
+            Entity = entity;
+            Player = player;
+            Force = force;
+        }
+    }
+
+    /// <summary>
+    ///     Raise this directed event to detach a player from an entity.
+    /// </summary>
+    public class DetachPlayerEvent : EntityEventArgs
+    {
+        /// <summary>
+        ///     Whether the player was detached correctly.
+        ///     Fails if no player was attached to the entity.
+        ///     Output parameter.
+        /// </summary>
+        public bool Result { get; set; } = false;
+    }
+
+    /// <summary>
+    ///     Event for when a player has been attached to an entity.
+    /// </summary>
+    public class PlayerAttachedEvent : EntityEventArgs
+    {
+        public IEntity Entity { get; }
+        public IPlayerSession Player { get; }
+
+        public PlayerAttachedEvent(IEntity entity, IPlayerSession player)
+        {
+            Entity = entity;
+            Player = player;
+        }
+    }
+
+    /// <summary>
+    ///     Event for when a player has been detached from an entity.
+    /// </summary>
+    public class PlayerDetachedEvent : EntityEventArgs
+    {
+        public IEntity Entity { get; }
+        public IPlayerSession Player { get; }
+
+        public PlayerDetachedEvent(IEntity entity, IPlayerSession player)
+        {
+            Entity = entity;
+            Player = player;
+        }
+    }
+}

Robust.Server/GameObjects/EntitySystems/InputSystem.cs

@@ -30,6 +30,8 @@ namespace Robust.Server.GameObjects
         /// <inheritdoc />
         public override void Shutdown()
         {
+            base.Shutdown();
+
             _playerManager.PlayerStatusChanged -= OnPlayerStatusChanged;
         }
 

Robust.Server/GameObjects/EntitySystems/TileLookup/GridTileLookupSystem.cs

@@ -16,6 +16,7 @@ namespace Robust.Server.GameObjects
     [UsedImplicitly]
     public sealed class GridTileLookupSystem : EntitySystem
     {
+        [Dependency] private readonly IEntityLookup _lookup = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
 
         private readonly Dictionary<GridId, Dictionary<Vector2i, GridTileLookupChunk>> _graph =
@@ -198,16 +199,16 @@ namespace Robust.Server.GameObjects
 
         private Box2 GetEntityBox(IEntity entity)
         {
-            // Need to clip the aabb as anything with an edge intersecting another tile might be picked up, such as walls.
-            if (entity.TryGetComponent(out IPhysBody? physics))
-                return new Box2(physics.GetWorldAABB().BottomLeft + 0.01f, physics.GetWorldAABB().TopRight - 0.01f);
-
-            // Don't want to accidentally get neighboring tiles unless we're near an edge
-            return Box2.CenteredAround(entity.Transform.Coordinates.ToMapPos(EntityManager), Vector2.One / 2);
+            var aabb = _lookup.GetWorldAabbFromEntity(entity);
+            return aabb.IsEmpty() ? aabb : aabb.Enlarged(-0.1f);
         }
 
         public override void Initialize()
         {
+            base.Initialize();
+#if DEBUG
+            SubscribeNetworkEvent<RequestGridTileLookupMessage>(HandleRequest);
+#endif
             SubscribeLocalEvent<MoveEvent>(HandleEntityMove);
             SubscribeLocalEvent<EntityInitializedMessage>(HandleEntityInitialized);
             SubscribeLocalEvent<EntityDeletedMessage>(HandleEntityDeleted);
@@ -219,14 +220,20 @@ namespace Robust.Server.GameObjects
         public override void Shutdown()
         {
             base.Shutdown();
-            UnsubscribeLocalEvent<MoveEvent>();
-            UnsubscribeLocalEvent<EntityInitializedMessage>();
-            UnsubscribeLocalEvent<EntityDeletedMessage>();
+
             _mapManager.OnGridCreated -= HandleGridCreated;
             _mapManager.OnGridRemoved -= HandleGridRemoval;
             _mapManager.TileChanged -= HandleTileChanged;
         }
 
+#if DEBUG
+        private void HandleRequest(RequestGridTileLookupMessage message, EntitySessionEventArgs args)
+        {
+            var entities = GetEntitiesIntersecting(message.GridId, message.Indices).Select(e => e.Uid).ToList();
+            RaiseNetworkEvent(new SendGridTileLookupMessage(message.GridId, message.Indices, entities), args.SenderSession.ConnectedClient);
+        }
+#endif
+
         private void HandleEntityInitialized(EntityInitializedMessage message)
         {
             HandleEntityAdd(message.Entity);
@@ -320,7 +327,12 @@ namespace Robust.Server.GameObjects
         /// <param name="moveEvent"></param>
         private void HandleEntityMove(MoveEvent moveEvent)
         {
-            if (moveEvent.Sender.Deleted || moveEvent.NewPosition.GetGridId(EntityManager) == GridId.Invalid || !moveEvent.NewPosition.IsValid(EntityManager))
+            // TODO: When Acruid does TileEntities we may actually be able to delete this system if tile lookups become fast enough
+            var gridId = moveEvent.NewPosition.GetGridId(EntityManager);
+
+            if (moveEvent.Sender.Deleted ||
+                gridId == GridId.Invalid ||
+                !moveEvent.NewPosition.IsValid(EntityManager))
             {
                 HandleEntityRemove(moveEvent.Sender);
                 return;
@@ -332,7 +344,7 @@ namespace Robust.Server.GameObjects
             }
 
             // Memory leak protection
-            var gridBounds = _mapManager.GetGrid(moveEvent.Sender.Transform.GridID).WorldBounds;
+            var gridBounds = _mapManager.GetGrid(gridId).WorldBounds;
             if (!gridBounds.Contains(moveEvent.Sender.Transform.WorldPosition))
             {
                 HandleEntityRemove(moveEvent.Sender);

Robust.Server/GameObjects/EntitySystems/UserInterfaceSystem.cs

@@ -22,6 +22,31 @@ namespace Robust.Server.GameObjects
         /// <inheritdoc />
         public override void Initialize()
         {
+            base.Initialize();
+
+            SubscribeNetworkEvent<BoundUIWrapMessage>(OnMessageReceived);
+            SubscribeLocalEvent<ServerUserInterfaceComponent, ComponentShutdown>(OnUserInterfaceShutdown);
+        }
+
+        private void OnUserInterfaceShutdown(EntityUid uid, ServerUserInterfaceComponent component, ComponentShutdown args)
+        {
+            foreach (var bui in component.Interfaces)
+            {
+                DeactivateInterface(bui);
+            }
+        }
+
+        internal void SendTo(IPlayerSession session, BoundUIWrapMessage msg)
+        {
+            RaiseNetworkEvent(msg, session.ConnectedClient);
+        }
+
+        private void OnMessageReceived(BoundUIWrapMessage msg, EntitySessionEventArgs args)
+        {
+            if (!ComponentManager.TryGetComponent<ServerUserInterfaceComponent>(msg.Entity, out var uiComp))
+                return;
+
+            uiComp.ReceiveMessage((IPlayerSession) args.SenderSession, msg);
         }
 
         /// <inheritdoc />

Robust.Server/GameObjects/ServerComponentFactory.cs

@@ -1,68 +1,37 @@
 using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 
-using Robust.Shared.Physics;
-
 namespace Robust.Server.GameObjects
 {
     public class ServerComponentFactory : ComponentFactory
     {
         public ServerComponentFactory()
         {
-            // Required for the engine to work
-            Register<MetaDataComponent>();
-            RegisterReference<MetaDataComponent, IMetaDataComponent>();
-
-            // Required for the engine to work
-            Register<TransformComponent>();
-            RegisterReference<TransformComponent, ITransformComponent>();
-
-            Register<MapComponent>();
-            RegisterReference<MapComponent, IMapComponent>();
-
-            Register<MapGridComponent>();
-            RegisterReference<MapGridComponent, IMapGridComponent>();
-
-            Register<EyeComponent>();
-            RegisterReference<EyeComponent, SharedEyeComponent>();
-
-            Register<BasicActorComponent>();
-            RegisterReference<BasicActorComponent, IActorComponent>();
-
-            Register<PhysicsComponent>();
-            RegisterReference<PhysicsComponent, IPhysBody>();
-
-            Register<CollisionWakeComponent>();
-
-            Register<ContainerManagerComponent>();
-            RegisterReference<ContainerManagerComponent, IContainerManager>();
-
-            Register<OccluderComponent>();
-
             RegisterIgnore("Input");
-            Register<SpriteComponent>();
-            RegisterReference<SpriteComponent, SharedSpriteComponent>();
-            RegisterReference<SpriteComponent, ISpriteRenderableComponent>();
-
-            Register<AppearanceComponent>();
-            RegisterReference<AppearanceComponent, SharedAppearanceComponent>();
-
-            Register<SnapGridComponent>();
-
-            Register<ServerUserInterfaceComponent>();
-            RegisterReference<ServerUserInterfaceComponent, SharedUserInterfaceComponent>();
-
-            Register<TimerComponent>();
-
             RegisterIgnore("AnimationPlayer");
 
-#if DEBUG
-            Register<DebugExceptionOnAddComponent>();
-            Register<DebugExceptionInitializeComponent>();
-            Register<DebugExceptionStartupComponent>();
-#endif
+            RegisterClass<MetaDataComponent>();
+            RegisterClass<TransformComponent>();
+            RegisterClass<MapComponent>();
+            RegisterClass<MapGridComponent>();
+            RegisterClass<EyeComponent>();
+            RegisterClass<ActorComponent>();
+            RegisterClass<PhysicsComponent>();
+            RegisterClass<CollisionWakeComponent>();
+            RegisterClass<ContainerManagerComponent>();
+            RegisterClass<OccluderComponent>();
+            RegisterClass<SpriteComponent>();
+            RegisterClass<AppearanceComponent>();
+            RegisterClass<SnapGridComponent>();
+            RegisterClass<ServerUserInterfaceComponent>();
+            RegisterClass<TimerComponent>();
+            RegisterClass<MapSaveIdComponent>();
 
-            Register<MapSaveIdComponent>();
+#if DEBUG
+            RegisterClass<DebugExceptionOnAddComponent>();
+            RegisterClass<DebugExceptionInitializeComponent>();
+            RegisterClass<DebugExceptionStartupComponent>();
+#endif
         }
     }
 }

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -9,7 +9,6 @@ using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Prototypes;
@@ -108,7 +107,7 @@ namespace Robust.Server.GameObjects
         /// <inheritdoc />
         public void SetupNetworking()
         {
-            _networkManager.RegisterNetMessage<MsgEntity>(MsgEntity.NAME, HandleEntityNetworkMessage);
+            _networkManager.RegisterNetMessage<MsgEntity>(HandleEntityNetworkMessage);
 
             _playerManager.PlayerStatusChanged += OnPlayerStatusChanged;
 
@@ -137,6 +136,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         public void SendComponentNetworkMessage(INetChannel? channel, IEntity entity, IComponent component,
             ComponentMessage message)
         {

Robust.Server/GameStates/EntityViewCulling.cs

@@ -132,11 +132,11 @@ namespace Robust.Server.GameStates
             if (session.Status != SessionStatus.InGame || session.AttachedEntityUid is null)
                 return viewers;
 
-            var query = _compMan.EntityQuery<BasicActorComponent>();
+            var query = _compMan.EntityQuery<ActorComponent>();
 
             foreach (var actorComp in query)
             {
-                if (actorComp.playerSession == session)
+                if (actorComp.PlayerSession == session)
                     viewers.Add(actorComp.Owner.Uid);
             }
 

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -12,7 +12,6 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Players;
@@ -63,8 +62,8 @@ namespace Robust.Server.GameStates
         /// <inheritdoc />
         public void Initialize()
         {
-            _networkManager.RegisterNetMessage<MsgState>(MsgState.NAME);
-            _networkManager.RegisterNetMessage<MsgStateAck>(MsgStateAck.NAME, HandleStateAck);
+            _networkManager.RegisterNetMessage<MsgState>();
+            _networkManager.RegisterNetMessage<MsgStateAck>(HandleStateAck);
 
             _networkManager.Connected += HandleClientConnected;
             _networkManager.Disconnect += HandleClientDisconnect;
@@ -211,7 +210,10 @@ namespace Robust.Server.GameStates
                     _logger.Log(LogLevel.Error, e, string.Empty);
                 }
 
-                return (new MsgState(session.ConnectedClient), null);
+                var msg = _networkManager.CreateNetMessage<MsgState>();
+                msg.MsgChannel = session.ConnectedClient;
+
+                return (msg, null);
             }
 
             var mailBag = _playerManager.GetAllPlayers()

Robust.Server/Placement/PlacementManager.cs

@@ -1,13 +1,13 @@
 using System;
-using Robust.Shared.IoC;
-using Robust.Shared.Map;
 using System.Collections.Generic;
 using System.Linq;
 using Robust.Server.GameObjects;
 using Robust.Server.Player;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
 using Robust.Shared.Log;
+using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
@@ -34,7 +34,7 @@ namespace Robust.Server.Placement
 
         public void Initialize()
         {
-            _networkManager.RegisterNetMessage<MsgPlacement>(MsgPlacement.NAME, HandleNetMessage);
+            _networkManager.RegisterNetMessage<MsgPlacement>(HandleNetMessage);
         }
 
         /// <summary>
@@ -212,7 +212,7 @@ namespace Robust.Server.Placement
             foreach (IEntity entity in IoCManager.Resolve<IEntityLookup>().GetEntitiesIntersecting(start.GetMapId(_entityManager),
                 new Box2(start.Position, start.Position + rectSize)))
             {
-                if (entity.Deleted || entity.HasComponent<IMapGridComponent>() || entity.HasComponent<IActorComponent>())
+                if (entity.Deleted || entity.HasComponent<IMapGridComponent>() || entity.HasComponent<ActorComponent>())
                     continue;
                 entity.Delete();
             }
@@ -223,10 +223,10 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementBegin(IEntity mob, int range, string objectType, string alignOption)
         {
-            if (!mob.TryGetComponent<IActorComponent>(out var actor))
+            if (!mob.TryGetComponent<ActorComponent>(out var actor))
                 return;
 
-            var playerConnection = actor.playerSession.ConnectedClient;
+            var playerConnection = actor.PlayerSession.ConnectedClient;
             if (playerConnection == null)
                 return;
 
@@ -244,10 +244,10 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementBeginTile(IEntity mob, int range, string tileType, string alignOption)
         {
-            if (!mob.TryGetComponent<IActorComponent>(out var actor))
+            if (!mob.TryGetComponent<ActorComponent>(out var actor))
                 return;
 
-            var playerConnection = actor.playerSession.ConnectedClient;
+            var playerConnection = actor.PlayerSession.ConnectedClient;
             if (playerConnection == null)
                 return;
 
@@ -265,10 +265,10 @@ namespace Robust.Server.Placement
         /// </summary>
         public void SendPlacementCancel(IEntity mob)
         {
-            if (!mob.TryGetComponent<IActorComponent>(out var actor))
+            if (!mob.TryGetComponent<ActorComponent>(out var actor))
                 return;
 
-            var playerConnection = actor.playerSession.ConnectedClient;
+            var playerConnection = actor.PlayerSession.ConnectedClient;
             if (playerConnection == null)
                 return;
 

Robust.Server/Player/IPlayerSession.cs

@@ -20,8 +20,8 @@ namespace Robust.Server.Player
         ///     NOTE: The content pack almost certainly has an alternative for this.
         ///     Do not call this directly for most content code.
         /// </summary>
-        /// <param name="a">The entity to attach to.</param>
-        void AttachToEntity(IEntity? a);
+        /// <param name="entity">The entity to attach to.</param>
+        void AttachToEntity(IEntity? entity);
 
         /// <summary>
         ///     Detaches this player from an entity.
@@ -36,5 +36,12 @@ namespace Robust.Server.Player
         ///     Persistent data for this player.
         /// </summary>
         IPlayerData Data { get; }
+
+        /// <summary>
+        ///     Internal method to set <see cref="ICommonSession.AttachedEntity"/> and update the player's status.
+        ///     Do NOT use this unless you know what you're doing, you probably want <see cref="AttachToEntity"/>
+        ///     and <see cref="DetachFromEntity"/> instead.
+        /// </summary>
+        internal void SetAttachedEntity(IEntity? entity);
     }
 }

Robust.Server/Player/PlayerHelpers.cs

@@ -10,10 +10,10 @@ namespace Robust.Server.Player
             if (entity == null)
                 return null;
             
-            if (!entity.TryGetComponent(out IActorComponent? actorComponent))
+            if (!entity.TryGetComponent(out ActorComponent? actorComponent))
                 return null;
 
-            return actorComponent.playerSession;
+            return actorComponent.PlayerSession;
         }
     }
 }

Robust.Server/Player/PlayerManager.cs

@@ -107,8 +107,8 @@ namespace Robust.Server.Player
 
             MaxPlayers = maxPlayers;
 
-            _network.RegisterNetMessage<MsgPlayerListReq>(MsgPlayerListReq.NAME, HandlePlayerListReq);
-            _network.RegisterNetMessage<MsgPlayerList>(MsgPlayerList.NAME);
+            _network.RegisterNetMessage<MsgPlayerListReq>(HandlePlayerListReq);
+            _network.RegisterNetMessage<MsgPlayerList>();
 
             _network.Connecting += OnConnecting;
             _network.Connected += NewSession;

Robust.Server/Player/PlayerSession.cs

@@ -6,6 +6,7 @@ using Robust.Shared.GameStates;
 using Robust.Shared.Network;
 using Robust.Shared.Players;
 using Robust.Shared.ViewVariables;
+using Logger = Robust.Shared.Log.Logger;
 
 namespace Robust.Server.Player
 {
@@ -36,7 +37,7 @@ namespace Robust.Server.Player
 
         [ViewVariables] public INetChannel ConnectedClient { get; }
 
-        [ViewVariables] public IEntity? AttachedEntity { get; private set; }
+        [ViewVariables] public IEntity? AttachedEntity { get; set; }
 
         [ViewVariables] public EntityUid? AttachedEntityUid => AttachedEntity?.Uid;
 
@@ -109,21 +110,21 @@ namespace Robust.Server.Player
         public event EventHandler<SessionStatusEventArgs>? PlayerStatusChanged;
 
         /// <inheritdoc />
-        public void AttachToEntity(IEntity? a)
+        public void AttachToEntity(IEntity? entity)
         {
             DetachFromEntity();
 
-            if (a == null)
-            {
+            if (entity == null)
                 return;
-            }
 
-            var actorComponent = a.AddComponent<BasicActorComponent>();
-            actorComponent.playerSession = this;
-            AttachedEntity = a;
-            a.SendMessage(actorComponent, new PlayerAttachedMsg(this));
-            a.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PlayerAttachSystemMessage(a, this));
-            UpdatePlayerState();
+            // This event needs to be broadcast.
+            var attachPlayer = new AttachPlayerEvent(entity, this);
+            entity.EntityManager.EventBus.RaiseLocalEvent(entity.Uid, attachPlayer);
+
+            if (!attachPlayer.Result)
+            {
+                Logger.Warning($"Couldn't attach player \"{this}\" to entity \"{entity}\"! Did it have a player already attached to it?");
+            }
         }
 
         /// <inheritdoc />
@@ -132,22 +133,12 @@ namespace Robust.Server.Player
             if (AttachedEntity == null)
                 return;
 
-            if (AttachedEntity.Deleted)
-            {
-                throw new InvalidOperationException("Tried to detach player, but my entity does not exist!");
-            }
+            var detachPlayer = new DetachPlayerEvent();
+            AttachedEntity.EntityManager.EventBus.RaiseLocalEvent(AttachedEntity.Uid, detachPlayer, false);
 
-            if (AttachedEntity.TryGetComponent<BasicActorComponent>(out var actor))
+            if (!detachPlayer.Result)
             {
-                AttachedEntity.SendMessage(actor, new PlayerDetachedMsg(this));
-                AttachedEntity.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PlayerDetachedSystemMessage(AttachedEntity));
-                AttachedEntity.RemoveComponent<BasicActorComponent>();
-                AttachedEntity = null;
-                UpdatePlayerState();
-            }
-            else
-            {
-                throw new InvalidOperationException("Tried to detach player, but entity does not have ActorComponent!");
+                Logger.Warning($"Couldn't detach player \"{this}\" to entity \"{AttachedEntity}\"! Is it missing an ActorComponent?");
             }
         }
 
@@ -190,6 +181,13 @@ namespace Robust.Server.Player
 
         public LoginType AuthType => ConnectedClient.AuthType;
 
+        /// <inheritdoc />
+        void IPlayerSession.SetAttachedEntity(IEntity? entity)
+        {
+            AttachedEntity = entity;
+            UpdatePlayerState();
+        }
+
         private void UpdatePlayerState()
         {
             PlayerState.Status = Status;

Robust.Server/Prototypes/ServerPrototypeManager.cs

@@ -24,7 +24,7 @@ namespace Robust.Server.Prototypes
         {
             base.Initialize();
 
-            _netManager.RegisterNetMessage<MsgReloadPrototypes>(MsgReloadPrototypes.NAME, HandleReloadPrototypes, NetMessageAccept.Server);
+            _netManager.RegisterNetMessage<MsgReloadPrototypes>(HandleReloadPrototypes, NetMessageAccept.Server);
         }
 
         private void HandleReloadPrototypes(MsgReloadPrototypes msg)

Robust.Server/Scripting/ScriptHost.cs

@@ -36,11 +36,11 @@ namespace Robust.Server.Scripting
 
         public void Initialize()
         {
-            _netManager.RegisterNetMessage<MsgScriptStop>(MsgScriptStop.NAME, ReceiveScriptEnd);
-            _netManager.RegisterNetMessage<MsgScriptEval>(MsgScriptEval.NAME, ReceiveScriptEval);
-            _netManager.RegisterNetMessage<MsgScriptStart>(MsgScriptStart.NAME, ReceiveScriptStart);
-            _netManager.RegisterNetMessage<MsgScriptResponse>(MsgScriptResponse.NAME);
-            _netManager.RegisterNetMessage<MsgScriptStartAck>(MsgScriptStartAck.NAME);
+            _netManager.RegisterNetMessage<MsgScriptStop>(ReceiveScriptEnd);
+            _netManager.RegisterNetMessage<MsgScriptEval>(ReceiveScriptEval);
+            _netManager.RegisterNetMessage<MsgScriptStart>(ReceiveScriptStart);
+            _netManager.RegisterNetMessage<MsgScriptResponse>();
+            _netManager.RegisterNetMessage<MsgScriptStartAck>();
 
             _playerManager.PlayerStatusChanged += PlayerManagerOnPlayerStatusChanged;
         }

Robust.Server/ServerIoC.cs

@@ -46,7 +46,7 @@ namespace Robust.Server
             IoCManager.Register<IMapManagerInternal, ServerMapManager>();
             IoCManager.Register<IServerMapManager, ServerMapManager>();
             IoCManager.Register<IEntityManager, ServerEntityManager>();
-            IoCManager.Register<IEntityLookup, SharedEntityLookup>();
+            IoCManager.Register<IEntityLookup, EntityLookup>();
             IoCManager.Register<IEntityNetworkManager, ServerEntityManager>();
             IoCManager.Register<IServerEntityNetworkManager, ServerEntityManager>();
             IoCManager.Register<IMapLoader, MapLoader>();

Robust.Server/ViewVariables/ViewVariablesHost.cs

@@ -13,7 +13,7 @@ using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
-using DenyReason = Robust.Shared.Network.Messages.MsgViewVariablesDenySession.DenyReason;
+using static Robust.Shared.Network.Messages.MsgViewVariablesDenySession;
 
 namespace Robust.Server.ViewVariables
 {
@@ -34,16 +34,13 @@ namespace Robust.Server.ViewVariables
 
         public void Initialize()
         {
-            _netManager.RegisterNetMessage<MsgViewVariablesReqSession>(MsgViewVariablesReqSession.NAME,
-                _msgReqSession);
-            _netManager.RegisterNetMessage<MsgViewVariablesReqData>(MsgViewVariablesReqData.NAME, _msgReqData);
-            _netManager.RegisterNetMessage<MsgViewVariablesModifyRemote>(MsgViewVariablesModifyRemote.NAME,
-                _msgModifyRemote);
-            _netManager.RegisterNetMessage<MsgViewVariablesCloseSession>(MsgViewVariablesCloseSession.NAME,
-                _msgCloseSession);
-            _netManager.RegisterNetMessage<MsgViewVariablesDenySession>(MsgViewVariablesDenySession.NAME);
-            _netManager.RegisterNetMessage<MsgViewVariablesOpenSession>(MsgViewVariablesOpenSession.NAME);
-            _netManager.RegisterNetMessage<MsgViewVariablesRemoteData>(MsgViewVariablesRemoteData.NAME);
+            _netManager.RegisterNetMessage<MsgViewVariablesReqSession>(_msgReqSession);
+            _netManager.RegisterNetMessage<MsgViewVariablesReqData>(_msgReqData);
+            _netManager.RegisterNetMessage<MsgViewVariablesModifyRemote>(_msgModifyRemote);
+            _netManager.RegisterNetMessage<MsgViewVariablesCloseSession>(_msgCloseSession);
+            _netManager.RegisterNetMessage<MsgViewVariablesDenySession>();
+            _netManager.RegisterNetMessage<MsgViewVariablesOpenSession>();
+            _netManager.RegisterNetMessage<MsgViewVariablesRemoteData>();
         }
 
         private void _msgCloseSession(MsgViewVariablesCloseSession message)

Robust.Shared/CVars.cs

@@ -463,5 +463,12 @@ namespace Robust.Shared
         /// </summary>
         public static readonly CVarDef<int> DebugTargetFps =
             CVarDef.Create("debug.target_fps", 60, CVar.CLIENTONLY | CVar.ARCHIVE);
+
+        /*
+         * MIDI
+         */
+
+        public static readonly CVarDef<float> MidiVolume =
+            CVarDef.Create("midi.volume", 0f, CVar.CLIENTONLY | CVar.ARCHIVE);
     }
 }

Robust.Shared/Configuration/NetConfigurationManager.cs

@@ -82,7 +82,7 @@ namespace Robust.Shared.Configuration
                 _netManager.Disconnect += PeerDisconnected;
             }
 
-            _netManager.RegisterNetMessage<MsgConVars>(MsgConVars.NAME, HandleNetVarMessage);
+            _netManager.RegisterNetMessage<MsgConVars>(HandleNetVarMessage);
         }
 
         private void PeerConnected(object? sender, NetChannelArgs e)

Robust.Shared/Containers/ContainerContentsModifiedMessage.cs

@@ -1,3 +1,4 @@
+using System;
 using Robust.Shared.GameObjects;
 
 namespace Robust.Shared.Containers
@@ -5,6 +6,7 @@ namespace Robust.Shared.Containers
     /// <summary>
     /// The contents of this container have been changed.
     /// </summary>
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
     public class ContainerContentsModifiedMessage : ComponentMessage
     {
         /// <summary>
@@ -35,4 +37,4 @@ namespace Robust.Shared.Containers
             Removed = removed;
         }
     }
-}
+}

Robust.Shared/Containers/ContainerHelpers.cs

@@ -197,6 +197,27 @@ namespace Robust.Shared.Containers
             return userContainer == otherContainer;
         }
 
+        public static bool IsInSameOrParentContainer(this IEntity user, IEntity other)
+        {
+            DebugTools.AssertNotNull(user);
+            DebugTools.AssertNotNull(other);
+
+            var isUserContained = TryGetContainer(user, out var userContainer);
+            var isOtherContained = TryGetContainer(other, out var otherContainer);
+
+            // Both entities are not in a container
+            if (!isUserContained && !isOtherContained) return true;
+
+            // One contains the other
+            if (userContainer?.Owner == other || otherContainer?.Owner == user) return true;
+
+            // Both entities are in different contained states
+            if (isUserContained != isOtherContained) return false;
+
+            // Both entities are in the same container
+            return userContainer == otherContainer;
+        }
+
         /// <summary>
         /// Shortcut method to make creation of containers easier.
         /// Creates a new container on the entity and gives it back to you.

Robust.Shared/Containers/ContainerManagerComponent.cs

@@ -16,8 +16,7 @@ namespace Robust.Shared.Containers
     /// <summary>
     /// Holds data about a set of entity containers on this entity.
     /// </summary>
-    // [RegisterComponent]
-    // [ComponentReference(typeof(IContainerManager))]
+    [ComponentReference(typeof(IContainerManager))]
     public class ContainerManagerComponent : Component, IContainerManager
     {
         [Dependency] private readonly IRobustSerializer _serializer = default!;

Robust.Shared/ContentPack/AssemblyTypeChecker.cs

@@ -106,6 +106,12 @@ namespace Robust.Shared.ContentPack
 
             var asmName = reader.GetString(reader.GetAssemblyDefinition().Name);
 
+            if (peReader.PEHeaders.CorHeader?.ManagedNativeHeaderDirectory is {Size: not 0})
+            {
+                _sawmill.Error($"Assembly {asmName} contains native code.");
+                return false;
+            }
+
             if (VerifyIL)
             {
                 if (!DoVerifyIL(asmName, resolver, peReader, reader))
@@ -404,7 +410,8 @@ namespace Robust.Shared.ContentPack
             }
         }
 
-        private bool IsTypeAccessAllowed(SandboxConfig sandboxConfig, MTypeReferenced type, [NotNullWhen(true)] out TypeConfig? cfg)
+        private bool IsTypeAccessAllowed(SandboxConfig sandboxConfig, MTypeReferenced type,
+            [NotNullWhen(true)] out TypeConfig? cfg)
         {
             if (type.Namespace == null)
             {

Robust.Shared/GameObjects/Component.cs

@@ -210,9 +210,11 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         public virtual void HandleMessage(ComponentMessage message, IComponent? component) { }
 
         /// <inheritdoc />
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         public virtual void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel, ICommonSession? session = null) { }
 
         /// <param name="player"></param>

Robust.Shared/GameObjects/ComponentManager.cs

@@ -21,6 +21,8 @@ namespace Robust.Shared.GameObjects
         [Dependency] private readonly IRuntimeLog _runtimeLog = default!;
 #endif
 
+        public IComponentFactory ComponentFactory => _componentFactory;
+
         private const int TypeCapacity = 32;
         private const int ComponentCollectionCapacity = 1024;
         private const int EntityCapacity = 1024;

Robust.Shared/GameObjects/ComponentMessage.cs

@@ -7,6 +7,7 @@ namespace Robust.Shared.GameObjects
     ///     A message containing info to send through the component message system.
     /// </summary>
     [Serializable, NetSerializable]
+    [Obsolete("Component messages are deprecated. Use directed local events instead.")]
     public abstract class ComponentMessage
     {
         /// <summary>

Robust.Shared/GameObjects/ComponentMessages/Messages.cs

@@ -1,7 +1,9 @@
-using JetBrains.Annotations;
+using System;
+using JetBrains.Annotations;
 
 namespace Robust.Shared.GameObjects
 {
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
     public class RelayMovementEntityMessage : ComponentMessage
     {
         [PublicAPI]
@@ -16,6 +18,7 @@ namespace Robust.Shared.GameObjects
     /// <summary>
     ///     The entity transform parent has been changed.
     /// </summary>
+    [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
     public class ParentChangedMessage : ComponentMessage
     {
         /// <summary>

Robust.Shared/GameObjects/Components/Collidable/PhysicsComponent.Collision.cs

@@ -30,12 +30,6 @@ namespace Robust.Shared.GameObjects
         void CollideWith(Fixture ourFixture, Fixture otherFixture, in Manifold manifold);
     }
 
-    public interface ICollideSpecial
-    {
-        [Obsolete("Use PreventCollideEvent instead")]
-        bool PreventCollide(IPhysBody collidedwith);
-    }
-
     [Serializable, NetSerializable]
     public enum BodyStatus: byte
     {

Robust.Shared/GameObjects/Components/Collidable/PhysicsComponent.Physics.cs

@@ -24,6 +24,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Robust.Shared.Containers;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
@@ -98,7 +99,6 @@ namespace Robust.Shared.GameObjects
                 if (_bodyType == value)
                     return;
 
-                var oldAnchored = _bodyType == BodyType.Static;
                 var oldType = _bodyType;
                 _bodyType = value;
 
@@ -121,14 +121,7 @@ namespace Robust.Shared.GameObjects
 
                 RegenerateContacts();
 
-                var anchored = value == BodyType.Static;
-
                 Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new PhysicsBodyTypeChangedEvent(_bodyType, oldType), false);
-
-                if (oldAnchored != anchored)
-                {
-                    SendMessage(new AnchoredChangedMessage(Anchored));
-                }
             }
         }
 
@@ -171,11 +164,11 @@ namespace Robust.Shared.GameObjects
             if (value)
             {
                 _sleepTime = 0.0f;
-                Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PhysicsWakeMessage(this));
+                Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new PhysicsWakeMessage(this));
             }
             else
             {
-                Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PhysicsSleepMessage(this));
+                Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new PhysicsSleepMessage(this));
                 ResetDynamics();
                 _sleepTime = 0.0f;
             }
@@ -269,10 +262,7 @@ namespace Robust.Shared.GameObjects
             {
                 fixture.Body = this;
                 fixture.ComputeProperties();
-                if (string.IsNullOrEmpty(fixture.Name))
-                {
-                    fixture.Name = GetFixtureName(fixture);
-                }
+                fixture.ID = GetFixtureName(fixture);
             }
 
             ResetMassData();
@@ -312,60 +302,76 @@ namespace Robust.Shared.GameObjects
 
             // We will pray that this deferred joint is handled properly.
 
-            // TODO: Crude as FUCK diffing here as well, fine for now.
             /*
              * -- Joints --
              */
 
-            var existingJoints = new List<Joint>();
+            // TODO: Iterating like this is inefficient and bloated as fuck but on the other hand the linked-list is very convenient
+            // for bodies with a large number of fixtures / joints.
+            // Probably store them in Dictionaries but still store the linked-list stuff on the fixture / joint itself.
+            var existingJoints = Joints.ToList();
+            var toAddJoints = new List<Joint>();
+            var toRemoveJoints = new List<Joint>();
 
-            for (var je = JointEdges; je != null; je = je.Next)
+            foreach (var newJoint in newState.Joints)
             {
-                existingJoints.Add(je.Joint);
-            }
+                var jointFound = false;
 
-            var jointsDiff = true;
-
-            if (existingJoints.Count == newState.Joints.Count)
-            {
-                var anyDiff = false;
-                for (var i = 0; i < existingJoints.Count; i++)
+                foreach (var joint in existingJoints)
                 {
-                    var existing = existingJoints[i];
-                    var newJoint = newState.Joints[i];
-
-                    if (!existing.Equals(newJoint))
+                    if (joint.ID.Equals(newJoint.ID))
                     {
-                        anyDiff = true;
+                        if (!newJoint.Equals(joint) && TrySetupNetworkedJoint(newJoint))
+                        {
+                            toAddJoints.Add(newJoint);
+                            toRemoveJoints.Add(joint);
+                        }
+
+                        jointFound = true;
                         break;
                     }
                 }
 
-                if (!anyDiff)
+                if (!jointFound && TrySetupNetworkedJoint(newJoint))
                 {
-                    jointsDiff = false;
+                    toAddJoints.Add(newJoint);
                 }
             }
 
-            if (jointsDiff)
+            foreach (var joint in existingJoints)
             {
-                ClearJoints();
+                var jointFound = false;
 
-                foreach (var joint in newState.Joints)
+                foreach (var newJoint in newState.Joints)
                 {
-                    joint.EdgeA = new JointEdge();
-                    joint.EdgeB = new JointEdge();
-                    // Defer joints given it relies on 2 bodies.
-                    AddJoint(joint);
+                    if (joint.ID.Equals(newJoint.ID))
+                    {
+                        jointFound = true;
+                        break;
+                    }
                 }
+
+                if (jointFound) continue;
+
+                toRemoveJoints.Add(joint);
+            }
+
+            foreach (var joint in toRemoveJoints)
+            {
+                RemoveJoint(joint);
+            }
+
+            foreach (var joint in toAddJoints)
+            {
+                AddJoint(joint);
             }
 
             /*
              * -- Fixtures --
              */
 
-            var toAdd = new List<Fixture>();
-            var toRemove = new List<Fixture>();
+            var toAddFixtures = new List<Fixture>();
+            var toRemoveFixtures = new List<Fixture>();
             var computeProperties = false;
 
             // Given a bunch of data isn't serialized need to sort of re-initialise it
@@ -385,12 +391,12 @@ namespace Robust.Shared.GameObjects
 
                 foreach (var existing in _fixtures)
                 {
-                    if (!fixture.Name.Equals(existing.Name)) continue;
+                    if (!fixture.ID.Equals(existing.ID)) continue;
 
                     if (!fixture.Equals(existing))
                     {
-                        toAdd.Add(fixture);
-                        toRemove.Add(existing);
+                        toAddFixtures.Add(fixture);
+                        toRemoveFixtures.Add(existing);
                     }
 
                     found = true;
@@ -399,7 +405,7 @@ namespace Robust.Shared.GameObjects
 
                 if (!found)
                 {
-                    toAdd.Add(fixture);
+                    toAddFixtures.Add(fixture);
                 }
             }
 
@@ -410,7 +416,7 @@ namespace Robust.Shared.GameObjects
 
                 foreach (var fixture in newFixtures)
                 {
-                    if (fixture.Name.Equals(existing.Name))
+                    if (fixture.ID.Equals(existing.ID))
                     {
                         found = true;
                         break;
@@ -419,18 +425,18 @@ namespace Robust.Shared.GameObjects
 
                 if (!found)
                 {
-                    toRemove.Add(existing);
+                    toRemoveFixtures.Add(existing);
                 }
             }
 
-            foreach (var fixture in toRemove)
+            foreach (var fixture in toRemoveFixtures)
             {
                 computeProperties = true;
                 RemoveFixture(fixture);
             }
 
             // TODO: We also still need event listeners for shapes (Probably need C# events)
-            foreach (var fixture in toAdd)
+            foreach (var fixture in toAddFixtures)
             {
                 computeProperties = true;
                 AddFixture(fixture);
@@ -454,6 +460,29 @@ namespace Robust.Shared.GameObjects
             Predict = false;
         }
 
+        private bool TrySetupNetworkedJoint(Joint joint)
+        {
+            // This can fail if we've already deleted the entity or remove physics from it I think?
+
+            if (!Owner.EntityManager.TryGetEntity(joint.BodyAUid, out var entityA) ||
+                !entityA.TryGetComponent(out PhysicsComponent? bodyA))
+            {
+                return false;
+            }
+
+            if (!Owner.EntityManager.TryGetEntity(joint.BodyBUid, out var entityB) ||
+                !entityB.TryGetComponent(out PhysicsComponent? bodyB))
+            {
+                return false;
+            }
+
+            joint.BodyA = bodyA;
+            joint.BodyB = bodyB;
+            joint.EdgeA = new JointEdge();
+            joint.EdgeB = new JointEdge();
+            return true;
+        }
+
         public Fixture? GetFixture(string name)
         {
             // Sooo I'd rather have fixtures as a list in serialization but there's not really an easy way to have it as a
@@ -463,7 +492,7 @@ namespace Robust.Shared.GameObjects
             // If we really need it then you just deserialize onto a dummy field that then just never gets used again.
             foreach (var fixture in _fixtures)
             {
-                if (fixture.Name.Equals(name))
+                if (fixture.ID.Equals(name))
                 {
                     return fixture;
                 }
@@ -485,35 +514,18 @@ namespace Robust.Shared.GameObjects
             Dirty();
         }
 
-        public Box2 GetWorldAABB(IMapManager? mapManager = null)
+        public Box2 GetWorldAABB(Vector2? worldPosition = null, Angle? worldRotation = null)
         {
-            mapManager ??= IoCManager.Resolve<IMapManager>();
-            var bounds = new Box2();
+            worldRotation ??= Owner.Transform.WorldRotation;
+            worldPosition ??= Owner.Transform.WorldPosition;
+            var bounds = new Box2(worldPosition.Value, worldPosition.Value);
 
             foreach (var fixture in _fixtures)
             {
-                foreach (var (gridId, proxies) in fixture.Proxies)
-                {
-                    Vector2 offset;
-
-                    if (gridId == GridId.Invalid)
-                    {
-                        offset = Vector2.Zero;
-                    }
-                    else
-                    {
-                        offset = mapManager.GetGrid(gridId).WorldPosition;
-                    }
-
-                    foreach (var proxy in proxies)
-                    {
-                        var shapeBounds = proxy.AABB.Translated(offset);
-                        bounds = bounds.IsEmpty() ? shapeBounds : bounds.Union(shapeBounds);
-                    }
-                }
+                bounds = bounds.Union(fixture.Shape.CalculateLocalBounds(worldRotation.Value).Translated(worldPosition.Value));
             }
 
-            return bounds.IsEmpty() ? Box2.UnitCentered.Translated(Owner.Transform.WorldPosition) : bounds;
+            return bounds;
         }
 
         /// <inheritdoc />
@@ -554,7 +566,6 @@ namespace Robust.Shared.GameObjects
                     return;
 
                 _canCollide = value;
-
                 Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new CollisionChangeMessage(this, Owner.Uid, _canCollide));
                 Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PhysicsUpdateMessage(this));
                 Dirty();
@@ -900,35 +911,6 @@ namespace Robust.Shared.GameObjects
             }
         }
 
-        /// <summary>
-        ///     Whether or not the entity is anchored in place.
-        /// </summary>
-        [ViewVariables(VVAccess.ReadWrite)]
-        [Obsolete("Use BodyType.Static instead")]
-        public bool Anchored
-        {
-            get => BodyType == BodyType.Static;
-            set
-            {
-                var anchored = BodyType == BodyType.Static;
-
-                if (anchored == value)
-                    return;
-
-                if (value)
-                {
-                    _bodyType = BodyType.Static;
-                }
-                else
-                {
-                    _bodyType = BodyType.Dynamic;
-                }
-
-                SendMessage(new AnchoredChangedMessage(Anchored));
-                Dirty();
-            }
-        }
-
         [ViewVariables(VVAccess.ReadWrite)]
         public bool Predict
         {
@@ -1005,12 +987,46 @@ namespace Robust.Shared.GameObjects
             Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new FixtureUpdateMessage(this, fixture));
         }
 
-        internal string GetFixtureName(Fixture fixture)
+        private string GetFixtureName(Fixture fixture)
         {
+            if (!string.IsNullOrEmpty(fixture.ID)) return fixture.ID;
+
             // For any fixtures that aren't named in the code we will assign one.
             return $"fixture-{_fixtures.IndexOf(fixture)}";
         }
 
+        private string GetJointName(Joint joint)
+        {
+            var id = joint.ID;
+
+            if (!string.IsNullOrEmpty(id)) return id;
+
+            var jointCount = Joints.Count();
+
+            for (var i = 0; i < jointCount + 1; i++)
+            {
+                id = $"joint-{i}";
+                if (GetJoint(id) != null) continue;
+                return id;
+            }
+
+            Logger.WarningS("physics", $"Unable to get a joint ID; using its hashcode instead.");
+            return joint.GetHashCode().ToString();
+        }
+
+        /// <summary>
+        /// Get a joint with the specified ID.
+        /// </summary>
+        public Joint? GetJoint(string id)
+        {
+            foreach (var joint in Joints)
+            {
+                if (joint.ID == id) return joint;
+            }
+
+            return null;
+        }
+
         internal Transform GetTransform()
         {
             return new(Owner.Transform.WorldPosition, (float) Owner.Transform.WorldRotation.Theta);
@@ -1158,15 +1174,10 @@ namespace Robust.Shared.GameObjects
                 else
                 {
                     // TODO: Probably a bad idea but ehh future sloth's problem; namely that we have to duplicate code between here and CanCollide.
-                    Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new CollisionChangeMessage(this, Owner.Uid, _canCollide));
-                    Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local, new PhysicsUpdateMessage(this));
+                    Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new CollisionChangeMessage(this, Owner.Uid, _canCollide));
+                    Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new PhysicsUpdateMessage(this));
                 }
             }
-
-            if (EntitySystem.Get<SharedPhysicsSystem>().Maps.TryGetValue(Owner.Transform.MapID, out var map))
-            {
-                PhysicsMap = map;
-            }
         }
 
         public void ClearJoints()
@@ -1218,12 +1229,23 @@ namespace Robust.Shared.GameObjects
 
         public void AddJoint(Joint joint)
         {
+            var id = GetJointName(joint);
+
+            foreach (var existing in Joints)
+            {
+                // This can happen if a server created joint is sent and applied before the client can create it locally elsewhere
+                if (existing.ID.Equals(id)) return;
+            }
+
             PhysicsMap.AddJoint(joint);
+            joint.ID = id;
+            Logger.DebugS("physics", $"Added joint id: {joint.ID} type: {joint.GetType().Name} to {Owner}");
         }
 
         public void RemoveJoint(Joint joint)
         {
             PhysicsMap.RemoveJoint(joint);
+            Logger.DebugS("physics", $"Removed joint id: {joint.ID} type: {joint.GetType().Name} from {Owner}");
         }
 
         public override void OnRemove()
@@ -1331,30 +1353,15 @@ namespace Robust.Shared.GameObjects
 
             if (preventCollideMessage.Cancelled) return false;
 
-            foreach (var comp in Owner.GetAllComponents<ICollideSpecial>())
-            {
-                if (comp.PreventCollide(other)) return false;
-            }
+            preventCollideMessage = new PreventCollideEvent(other, this);
+            Owner.EntityManager.EventBus.RaiseLocalEvent(other.Owner.Uid, preventCollideMessage);
 
-            foreach (var comp in other.Owner.GetAllComponents<ICollideSpecial>())
-            {
-                if (comp.PreventCollide(this)) return false;
-            }
+            if (preventCollideMessage.Cancelled) return false;
 
             return true;
         }
     }
 
-    public class AnchoredChangedMessage : ComponentMessage
-    {
-        public readonly bool Anchored;
-
-        public AnchoredChangedMessage(bool anchored)
-        {
-            Anchored = anchored;
-        }
-    }
-
     /// <summary>
     ///     Directed event raised when an entity's physics BodyType changes.
     /// </summary>
@@ -1370,11 +1377,6 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         public BodyType Old { get; }
 
-        /// <summary>
-        ///     Whether the body is "anchored".
-        /// </summary>
-        public bool Anchored => New == BodyType.Static;
-
         public PhysicsBodyTypeChangedEvent(BodyType newType, BodyType oldType)
         {
             New = newType;

Robust.Shared/GameObjects/Components/ITransformComponent.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using JetBrains.Annotations;
 using Robust.Shared.Animations;
 using Robust.Shared.Map;
@@ -93,9 +94,6 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         bool IsMapTransform { get; }
 
-        /// <summary>
-        ///
-        /// </summary>
         Vector2? LerpDestination { get; }
 
         /// <summary>

Robust.Shared/GameObjects/Components/Map/MapComponent.cs

@@ -1,6 +1,5 @@
 using System;
 using Robust.Shared.Map;
-using Robust.Shared.Prototypes;
 using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Serialization.Manager.Attributes;
@@ -18,6 +17,7 @@ namespace Robust.Shared.GameObjects
     }
 
     /// <inheritdoc cref="IMapComponent"/>
+    [ComponentReference(typeof(IMapComponent))]
     public class MapComponent : Component, IMapComponent
     {
         [ViewVariables(VVAccess.ReadOnly)]

Robust.Shared/GameObjects/Components/Map/MapGridComponent.cs

@@ -21,6 +21,7 @@ namespace Robust.Shared.GameObjects
     }
 
     /// <inheritdoc cref="IMapGridComponent"/>
+    [ComponentReference(typeof(IMapGridComponent))]
     internal class MapGridComponent : Component, IMapGridComponent
     {
         [Dependency] private readonly IMapManager _mapManager = default!;
@@ -51,6 +52,17 @@ namespace Robust.Shared.GameObjects
             _gridIndex = GridId.Invalid;
         }
 
+        public override void Initialize()
+        {
+            base.Initialize();
+            var mapId = Owner.Transform.MapID;
+
+            if (_mapManager.HasMapEntity(mapId))
+            {
+                Owner.Transform.AttachParent(_mapManager.GetMapEntity(mapId));
+            }
+        }
+
         /// <param name="player"></param>
         /// <inheritdoc />
         public override ComponentState GetComponentState(ICommonSession player)

Robust.Shared/GameObjects/Components/MetaDataComponent.cs

@@ -65,6 +65,7 @@ namespace Robust.Shared.GameObjects
     }
 
     /// <inheritdoc cref="IMetaDataComponent"/>
+    [ComponentReference(typeof(IMetaDataComponent))]
     internal class MetaDataComponent : Component, IMetaDataComponent
     {
         [Dependency] private readonly IPrototypeManager _prototypes = default!;

Robust.Shared/GameObjects/Components/Transform/TransformComponent.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Robust.Shared.Animations;
 using Robust.Shared.Containers;
@@ -14,6 +15,7 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Shared.GameObjects
 {
+    [ComponentReference(typeof(ITransformComponent))]
     internal class TransformComponent : Component, ITransformComponent, IComponentDebug
     {
         [DataField("parent")]
@@ -65,25 +67,21 @@ namespace Robust.Shared.GameObjects
         [ViewVariables]
         public GridId GridID
         {
-            get
+            get => _gridId;
+            private set
             {
-                // root node, grid id is undefined
-                if (Owner.HasComponent<IMapComponent>())
-                    return GridId.Invalid;
-
-                // second level node, terminates recursion up the branch of the tree
-                if (Owner.TryGetComponent(out IMapGridComponent? gridComp))
-                    return gridComp.GridIndex;
-
-                // branch or leaf node
-                if (_parent.IsValid())
-                    return Parent!.GridID;
-
-                // Not on a grid
-                return GridId.Invalid;
+                if (_gridId.Equals(value)) return;
+                _gridId = value;
+                foreach (var transformComponent in Children)
+                {
+                    var child = (TransformComponent) transformComponent;
+                    child.GridID = value;
+                }
             }
         }
 
+        private GridId _gridId = GridId.Invalid;
+
         /// <inheritdoc />
         [ViewVariables(VVAccess.ReadWrite)]
         public bool NoLocalRotation
@@ -117,7 +115,7 @@ namespace Robust.Shared.GameObjects
 
                 // Set _nextRotation to null to break any active lerps if this is a client side prediction.
                 _nextRotation = null;
-                SetRotation(value);
+                _localRotation = value;
                 Dirty();
 
                 if (!DeferUpdates)
@@ -260,17 +258,51 @@ namespace Robust.Shared.GameObjects
                 var valid = _parent.IsValid();
                 return new EntityCoordinates(valid ? _parent : Owner.Uid, valid ? LocalPosition : Vector2.Zero);
             }
+            // NOTE: This setter must be callable from before initialize (inheriting from AttachParent's note)
             set
             {
                 var oldPosition = Coordinates;
+                _localPosition = value.Position;
+
+                var changedParent = false;
 
                 if (value.EntityId != _parent)
                 {
-                    var newEntity = Owner.EntityManager.GetEntity(value.EntityId);
-                    AttachParent(newEntity);
+                    changedParent = true;
+                    var newParentEnt = Owner.EntityManager.GetEntity(value.EntityId);
+                    var newParent = newParentEnt.Transform;
+
+                    DebugTools.Assert(newParent != this,
+                        $"Can't parent a {nameof(ITransformComponent)} to itself.");
+
+                    // That's already our parent, don't bother attaching again.
+
+                    var oldParent = Parent;
+                    var oldConcrete = (TransformComponent?) oldParent;
+                    var uid = Owner.Uid;
+                    oldConcrete?._children.Remove(uid);
+                    var newConcrete = (TransformComponent) newParent;
+                    newConcrete._children.Add(uid);
+
+                    var oldParentOwner = oldParent?.Owner;
+                    var entMessage = new EntParentChangedMessage(Owner, oldParentOwner);
+                    var compMessage = new ParentChangedMessage(newParentEnt, oldParentOwner);
+
+                    // offset position from world to parent
+                    _parent = newParentEnt.Uid;
+                    ChangeMapId(newConcrete.MapID);
+
+                    Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, entMessage);
+                    Owner.SendMessage(this, compMessage);
+
+                    GridID = GetGridIndex();
                 }
 
-                _localPosition = value.Position;
+                // These conditions roughly emulate the effects of the code before I changed things,
+                //  in regards to when to rebuild matrices.
+                // This may not in fact be the right thing.
+                if (changedParent || !DeferUpdates)
+                    RebuildMatrices();
                 Dirty();
 
                 if (!DeferUpdates)
@@ -278,7 +310,6 @@ namespace Robust.Shared.GameObjects
                     //TODO: This is a hack, look into WHY we can't call GridPosition before the comp is Running
                     if (Running)
                     {
-                        RebuildMatrices();
                         Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, new MoveEvent(Owner, oldPosition, Coordinates));
                     }
                 }
@@ -306,7 +337,7 @@ namespace Robust.Shared.GameObjects
                 _nextPosition = null;
 
                 var oldGridPos = Coordinates;
-                SetPosition(value);
+                _localPosition = value;
                 Dirty();
 
                 if (!DeferUpdates)
@@ -424,6 +455,28 @@ namespace Robust.Shared.GameObjects
                 // so duplicate additions (which will happen) don't matter.
                 ((TransformComponent) Parent!)._children.Add(Owner.Uid);
             }
+
+            GridID = GetGridIndex();
+        }
+
+        private GridId GetGridIndex()
+        {
+            if (Owner.HasComponent<IMapComponent>())
+            {
+                return GridId.Invalid;
+            }
+
+            if (Owner.TryGetComponent(out IMapGridComponent? gridComponent))
+            {
+                return gridComponent.GridIndex;
+            }
+
+            if (_parent.IsValid())
+            {
+                return Parent!.GridID;
+            }
+
+            return _mapManager.TryFindGridAt(MapID, WorldPosition, out var mapgrid) ? mapgrid.Index : GridId.Invalid;
         }
 
         /// <inheritdoc />
@@ -536,49 +589,22 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <summary>
-        /// Sets another entity as the parent entity.
+        /// Sets another entity as the parent entity, maintaining world position.
         /// </summary>
         /// <param name="newParent"></param>
         public virtual void AttachParent(ITransformComponent newParent)
         {
             //NOTE: This function must be callable from before initialize
 
-            // nothing to attach to.
+            // don't attach to something we're already attached to
             if (ParentUid == newParent.Owner.Uid)
                 return;
 
             DebugTools.Assert(newParent != this,
                 $"Can't parent a {nameof(ITransformComponent)} to itself.");
 
-            // That's already our parent, don't bother attaching again.
-            var newParentEnt = newParent.Owner;
-            if (newParentEnt.Uid == _parent)
-            {
-                return;
-            }
-
-            var oldParent = Parent;
-            var oldConcrete = (TransformComponent?) oldParent;
-            var uid = Owner.Uid;
-            oldConcrete?._children.Remove(uid);
-            var newConcrete = (TransformComponent) newParent;
-            newConcrete._children.Add(uid);
-
-            var oldParentOwner = oldParent?.Owner;
-            var entMessage = new EntParentChangedMessage(Owner, oldParentOwner);
-            var compMessage = new ParentChangedMessage(newParentEnt, oldParentOwner);
-
-            // offset position from world to parent
-            SetPosition(newParent.InvWorldMatrix.Transform(WorldPosition));
-            _parent = newParentEnt.Uid;
-
-            ChangeMapId(newConcrete.MapID);
-
-            Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, entMessage);
-            Owner.SendMessage(this, compMessage);
-            
-            RebuildMatrices();
-            Dirty();
+            // offset position from world to parent, and set
+            Coordinates = new EntityCoordinates(newParent.Owner.Uid, newParent.InvWorldMatrix.Transform(WorldPosition));
         }
 
         internal void ChangeMapId(MapId newMapId)
@@ -693,14 +719,14 @@ namespace Robust.Shared.GameObjects
 
                 if (LocalRotation != newState.Rotation)
                 {
-                    SetRotation(newState.Rotation);
+                    _localRotation = newState.Rotation;
                     rebuildMatrices = true;
                 }
 
                 if (!_localPosition.EqualsApprox(newState.LocalPosition, 0.0001))
                 {
                     var oldPos = Coordinates;
-                    SetPosition(newState.LocalPosition);
+                    _localPosition = newState.LocalPosition;
 
                     var ev = new MoveEvent(Owner, oldPos, Coordinates);
                     EntitySystem.Get<SharedTransformSystem>().DeferMoveEvent(ev);
@@ -735,17 +761,6 @@ namespace Robust.Shared.GameObjects
             }
         }
 
-        protected virtual void SetPosition(Vector2 position)
-        {
-            // DebugTools.Assert(!float.IsNaN(position.X) && !float.IsNaN(position.Y));
-            _localPosition = position;
-        }
-
-        protected virtual void SetRotation(Angle rotation)
-        {
-            _localRotation = rotation;
-        }
-
         public Matrix3 GetLocalMatrix()
         {
             return _localMatrix;

Robust.Shared/GameObjects/Components/UserInterface/SharedUserInterfaceComponent.cs

@@ -35,25 +35,6 @@ namespace Robust.Shared.GameObjects
                 UiKey = _uiKeyRaw;
             }
         }
-
-        [NetSerializable, Serializable]
-        protected sealed class BoundInterfaceMessageWrapMessage : ComponentMessage
-        {
-            public readonly BoundUserInterfaceMessage Message;
-            public readonly object UiKey;
-
-            public BoundInterfaceMessageWrapMessage(BoundUserInterfaceMessage message, object uiKey)
-            {
-                Directed = true;
-                Message = message;
-                UiKey = uiKey;
-            }
-
-            public override string ToString()
-            {
-                return $"{nameof(BoundInterfaceMessageWrapMessage)}: {Message}";
-            }
-        }
     }
 
     [NetSerializable, Serializable]
@@ -87,4 +68,24 @@ namespace Robust.Shared.GameObjects
     internal sealed class CloseBoundInterfaceMessage : BoundUserInterfaceMessage
     {
     }
+
+    [Serializable, NetSerializable]
+    internal sealed class BoundUIWrapMessage : EntityEventArgs
+    {
+        public readonly EntityUid Entity;
+        public readonly BoundUserInterfaceMessage Message;
+        public readonly object UiKey;
+
+        public BoundUIWrapMessage(EntityUid entity, BoundUserInterfaceMessage message, object uiKey)
+        {
+            Message = message;
+            UiKey = uiKey;
+            Entity = entity;
+        }
+
+        public override string ToString()
+        {
+            return $"{nameof(BoundUIWrapMessage)}: {Message}";
+        }
+    }
 }

Robust.Shared/GameObjects/Entity.cs

@@ -286,6 +286,12 @@ namespace Robust.Shared.GameObjects
             return TryGetComponent(type, out var component) ? component : null;
         }
 
+        /// <inheritdoc />
+        public void QueueDelete()
+        {
+            EntityManager.QueueDeleteEntity(this);
+        }
+
         /// <inheritdoc />
         public void Delete()
         {

Robust.Shared/GameObjects/EntityEventBus.Directed.cs

@@ -99,6 +99,7 @@ namespace Robust.Shared.GameObjects
         private class EventTables : IDisposable
         {
             private IEntityManager _entMan;
+            private IComponentFactory _comFac;
 
             // eUid -> EventType -> { CompType1, ... CompTypeN }
             private Dictionary<EntityUid, Dictionary<Type, HashSet<Type>>> _eventTables;
@@ -112,6 +113,7 @@ namespace Robust.Shared.GameObjects
             public EventTables(IEntityManager entMan)
             {
                 _entMan = entMan;
+                _comFac = entMan.ComponentManager.ComponentFactory;
 
                 _entMan.EntityAdded += OnEntityAdded;
                 _entMan.EntityDeleted += OnEntityDeleted;
@@ -194,18 +196,21 @@ namespace Robust.Shared.GameObjects
             {
                 var eventTable = _eventTables[euid];
 
-                if (!_subscriptions.TryGetValue(compType, out var compSubs))
-                    return;
-
-                foreach (var kvSub in compSubs)
+                foreach (var type in GetReferences(compType))
                 {
-                    if(!eventTable.TryGetValue(kvSub.Key, out var subscribedComps))
-                    {
-                        subscribedComps = new HashSet<Type>();
-                        eventTable.Add(kvSub.Key, subscribedComps);
-                    }
+                    if (!_subscriptions.TryGetValue(type, out var compSubs))
+                        continue;
 
-                    subscribedComps.Add(compType);
+                    foreach (var kvSub in compSubs)
+                    {
+                        if(!eventTable.TryGetValue(kvSub.Key, out var subscribedComps))
+                        {
+                            subscribedComps = new HashSet<Type>();
+                            eventTable.Add(kvSub.Key, subscribedComps);
+                        }
+
+                        subscribedComps.Add(type);
+                    }
                 }
             }
 
@@ -213,15 +218,18 @@ namespace Robust.Shared.GameObjects
             {
                 var eventTable = _eventTables[euid];
 
-                if (!_subscriptions.TryGetValue(compType, out var compSubs))
-                    return;
-
-                foreach (var kvSub in compSubs)
+                foreach (var type in GetReferences(compType))
                 {
-                    if (!eventTable.TryGetValue(kvSub.Key, out var subscribedComps))
-                        return;
+                    if (!_subscriptions.TryGetValue(type, out var compSubs))
+                        continue;
 
-                    subscribedComps.Remove(compType);
+                    foreach (var kvSub in compSubs)
+                    {
+                        if (!eventTable.TryGetValue(kvSub.Key, out var subscribedComps))
+                            return;
+
+                        subscribedComps.Remove(type);
+                    }
                 }
             }
 
@@ -241,19 +249,23 @@ namespace Robust.Shared.GameObjects
                         return;
 
                     var component = _entMan.ComponentManager.GetComponent(euid, compType);
+
                     handler(euid, component, args);
                 }
             }
 
             public void DispatchComponent(EntityUid euid, IComponent component, Type eventType, EntityEventArgs args)
             {
-                if (!_subscriptions.TryGetValue(component.GetType(), out var compSubs))
-                    return;
+                foreach (var type in GetReferences(component.GetType()))
+                {
+                    if (!_subscriptions.TryGetValue(type, out var compSubs))
+                        continue;
 
-                if (!compSubs.TryGetValue(eventType, out var handler))
-                    return;
+                    if (!compSubs.TryGetValue(eventType, out var handler))
+                        continue;
 
-                handler(euid, component, args);
+                    handler(euid, component, args);
+                }
             }
 
             public void ClearEntities()
@@ -281,6 +293,11 @@ namespace Robust.Shared.GameObjects
                 _eventTables = null!;
                 _subscriptions = null!;
             }
+
+            private IEnumerable<Type> GetReferences(Type type)
+            {
+                return _comFac.GetRegistration(type).References;
+            }
         }
 
         /// <inheritdoc />

Robust.Shared/GameObjects/EntityManager.cs

@@ -44,6 +44,8 @@ namespace Robust.Shared.GameObjects
         /// <inheritdoc />
         public virtual IEntityNetworkManager? EntityNetManager => null;
 
+        protected readonly HashSet<EntityUid> QueuedDeletions = new();
+
         /// <summary>
         ///     All entities currently stored in the manager.
         /// </summary>
@@ -112,6 +114,16 @@ namespace Robust.Shared.GameObjects
                 _eventBus.ProcessEventQueue();
             }
 
+            using (histogram?.WithLabels("QueuedDeletion").NewTimer())
+            {
+                foreach (var uid in QueuedDeletions)
+                {
+                    DeleteEntity(uid);
+                }
+
+                QueuedDeletions.Clear();
+            }
+
             using (histogram?.WithLabels("ComponentCull").NewTimer())
             {
                 _componentManager.CullRemovedComponents();
@@ -212,6 +224,7 @@ namespace Robust.Shared.GameObjects
             return false;
         }
 
+        [Obsolete("IEntityQuery is obsolete")]
         public IEnumerable<IEntity> GetEntities(IEntityQuery query)
         {
             return query.Match(this);
@@ -287,6 +300,16 @@ namespace Robust.Shared.GameObjects
             EventBus.RaiseEvent(EventSource.Local, new EntityDeletedMessage(entity));
         }
 
+        public void QueueDeleteEntity(IEntity entity)
+        {
+            QueueDeleteEntity(entity.Uid);
+        }
+
+        public void QueueDeleteEntity(EntityUid uid)
+        {
+            QueuedDeletions.Add(uid);
+        }
+
         public void DeleteEntity(EntityUid uid)
         {
             if (TryGetEntity(uid, out var entity))
@@ -359,7 +382,7 @@ namespace Robust.Shared.GameObjects
             // we want this called before adding components
             EntityAdded?.Invoke(this, entity.Uid);
 
-            // We do this after the event, so if the event throws we have not committed 
+            // We do this after the event, so if the event throws we have not committed
             Entities[entity.Uid] = entity;
             AllEntities.Add(entity);
 
@@ -457,6 +480,7 @@ namespace Robust.Shared.GameObjects
             var session = netMsg.Session;
             compMsg.Remote = true;
 
+#pragma warning disable 618
             var uid = netMsg.EntityUid;
             if (compMsg.Directed)
             {
@@ -470,6 +494,7 @@ namespace Robust.Shared.GameObjects
                     component.HandleNetworkMessage(compMsg, compChannel, session);
                 }
             }
+#pragma warning restore 618
         }
 
         /// <summary>

Robust.Shared/GameObjects/EntitySystem.Subscriptions.cs

@@ -0,0 +1,128 @@
+using System;
+using System.Collections.Generic;
+
+namespace Robust.Shared.GameObjects
+{
+    public abstract partial class EntitySystem
+    {
+        private List<SubBase>? _subscriptions;
+
+        protected void SubscribeNetworkEvent<T>(EntityEventHandler<T> handler)
+            where T : notnull
+        {
+            EntityManager.EventBus.SubscribeEvent(EventSource.Network, this, handler);
+
+            _subscriptions ??= new();
+            _subscriptions.Add(new SubBroadcast<T>(EventSource.Network));
+        }
+
+        protected void SubscribeNetworkEvent<T>(EntitySessionEventHandler<T> handler)
+            where T : notnull
+        {
+            EntityManager.EventBus.SubscribeSessionEvent(EventSource.Network, this, handler);
+
+            _subscriptions ??= new();
+            _subscriptions.Add(new SubBroadcast<EntitySessionMessage<T>>(EventSource.Network));
+        }
+
+        protected void SubscribeLocalEvent<T>(EntityEventHandler<T> handler)
+            where T : notnull
+        {
+            EntityManager.EventBus.SubscribeEvent(EventSource.Local, this, handler);
+
+            _subscriptions ??= new();
+            _subscriptions.Add(new SubBroadcast<T>(EventSource.Local));
+        }
+
+        protected void SubscribeLocalEvent<T>(EntitySessionEventHandler<T> handler)
+            where T : notnull
+        {
+            EntityManager.EventBus.SubscribeSessionEvent(EventSource.Local, this, handler);
+
+            _subscriptions ??= new();
+            _subscriptions.Add(new SubBroadcast<EntitySessionMessage<T>>(EventSource.Local));
+        }
+
+        [Obsolete("Unsubscribing of entity system events is now automatic")]
+        protected void UnsubscribeNetworkEvent<T>()
+            where T : notnull
+        {
+            EntityManager.EventBus.UnsubscribeEvent<T>(EventSource.Network, this);
+        }
+
+        [Obsolete("Unsubscribing of entity system events is now automatic")]
+        protected void UnsubscribeLocalEvent<T>()
+            where T : notnull
+        {
+            EntityManager.EventBus.UnsubscribeEvent<T>(EventSource.Local, this);
+        }
+
+
+        protected void SubscribeLocalEvent<TComp, TEvent>(ComponentEventHandler<TComp, TEvent> handler)
+            where TComp : IComponent
+            where TEvent : EntityEventArgs
+        {
+            EntityManager.EventBus.SubscribeLocalEvent(handler);
+
+            _subscriptions ??= new();
+            _subscriptions.Add(new SubLocal<TComp, TEvent>());
+        }
+
+        [Obsolete("Unsubscribing of entity system events is now automatic")]
+        protected void UnsubscribeLocalEvent<TComp, TEvent>(ComponentEventHandler<TComp, TEvent> handler)
+            where TComp : IComponent
+            where TEvent : EntityEventArgs
+        {
+            EntityManager.EventBus.UnsubscribeLocalEvent<TComp, TEvent>();
+        }
+
+        [Obsolete("Unsubscribing of entity system events is now automatic")]
+        protected void UnsubscribeLocalEvent<TComp, TEvent>()
+            where TComp : IComponent
+            where TEvent : EntityEventArgs
+        {
+            EntityManager.EventBus.UnsubscribeLocalEvent<TComp, TEvent>();
+        }
+
+        private void ShutdownSubscriptions()
+        {
+            if (_subscriptions == null)
+                return;
+
+            foreach (var sub in _subscriptions)
+            {
+                sub.Unsubscribe(this, EntityManager.EventBus);
+            }
+
+            _subscriptions = null;
+        }
+
+        private abstract class SubBase
+        {
+            public abstract void Unsubscribe(EntitySystem sys, IEventBus bus);
+        }
+
+        private sealed class SubBroadcast<T> : SubBase where T : notnull
+        {
+            private readonly EventSource _source;
+
+            public SubBroadcast(EventSource source)
+            {
+                _source = source;
+            }
+
+            public override void Unsubscribe(EntitySystem sys, IEventBus bus)
+            {
+                bus.UnsubscribeEvent<T>(_source, sys);
+            }
+        }
+
+        private sealed class SubLocal<TComp, TBase> : SubBase where TComp : IComponent where TBase : EntityEventArgs
+        {
+            public override void Unsubscribe(EntitySystem sys, IEventBus bus)
+            {
+                bus.UnsubscribeLocalEvent<TComp, TBase>();
+            }
+        }
+    }
+}