Make DOOM work

I think I lost this work originally

Robust.Client.NameGenerator/XamlUiPartialClassGenerator.cs

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

Robust.Client/Audio/Midi/MidiManager.cs

@@ -11,9 +11,11 @@ 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 +34,6 @@ 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 +41,11 @@ 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>
@@ -75,6 +64,7 @@ namespace Robust.Client.Audio.Midi
 
         private SharedBroadPhaseSystem _broadPhaseSystem = default!;
 
+        [ViewVariables]
         public bool IsAvailable
         {
             get
@@ -85,12 +75,29 @@ 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;
+
+                _volume = value;
+                _volumeDirty = true;
+            }
+        }
 
         private static readonly string[] LinuxSoundfonts =
         {
@@ -117,6 +124,7 @@ 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()
@@ -175,18 +183,6 @@ 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 +246,9 @@ namespace Robust.Client.Audio.Midi
                 }
 
                 lock (_renderers)
+                {
                     _renderers.Add(renderer);
+                }
 
                 return renderer;
             }
@@ -268,74 +266,79 @@ 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 +349,7 @@ namespace Robust.Client.Audio.Midi
             while (_alive)
             {
                 lock (_renderers)
+                {
                     for (var i = 0; i < _renderers.Count; i++)
                     {
                         var renderer = _renderers[i];
@@ -353,10 +357,11 @@ namespace Robust.Client.Audio.Midi
                             renderer.Render();
                         else
                         {
-                            ((IMidiRenderer)renderer).InternalDispose();
+                            renderer.InternalDispose();
                             _renderers.Remove(renderer);
                         }
                     }
+                }
 
                 Thread.Sleep(1);
             }
@@ -367,9 +372,13 @@ 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 +433,7 @@ 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 +457,7 @@ namespace Robust.Client.Audio.Midi
                 {
                     return -1;
                 }
+
                 return 0;
             }
 
@@ -468,10 +479,12 @@ 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

@@ -8,6 +8,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 using MidiEvent = NFluidsynth.MidiEvent;
 
 namespace Robust.Client.Audio.Midi
@@ -21,6 +22,17 @@ 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 +122,11 @@ 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 +176,7 @@ 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!;
@@ -188,8 +205,12 @@ namespace Robust.Client.Audio.Midi
         private readonly object _playerStateLock = new();
         private SequencerClientId _synthRegister;
         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 +224,7 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public byte MidiBank
         {
             get => _midiBank;
@@ -216,6 +238,7 @@ namespace Robust.Client.Audio.Midi
             }
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
         public uint MidiSoundfont
         {
             get => _midiSoundfont;
@@ -229,10 +252,16 @@ 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 +272,19 @@ 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 +296,11 @@ 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)
         {
@@ -294,7 +331,11 @@ 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 +373,13 @@ 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 +403,8 @@ namespace Robust.Client.Audio.Midi
 
         public void StopAllNotes()
         {
-            _synth.AllNotesOff(-1);
+            lock(_playerStateLock)
+                _synth.AllNotesOff(-1);
         }
 
         public void LoadSoundfont(string filename, bool resetPresets = false)
@@ -372,7 +419,12 @@ 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;
 
@@ -452,6 +504,7 @@ 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 +515,7 @@ namespace Robust.Client.Audio.Midi
             var timestamp = SequencerTick;
             var midiEv = (Shared.Audio.Midi.MidiEvent) midiEvent;
             midiEv.Tick = timestamp;
+            midiEvent.Dispose();
             SendMidiEvent(midiEv);
             return 0;
         }

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/Console/ScriptClient.cs

@@ -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/GameController/GameController.cs

@@ -93,7 +93,7 @@ namespace Robust.Client
             // Disable load context usage on content start.
             // This prevents Content.Client being loaded twice and things like csi blowing up because of it.
             _modLoader.SetUseLoadContext(!ContentStart);
-            _modLoader.SetEnableSandboxing(Options.Sandboxing);
+            _modLoader.SetEnableSandboxing(false && Options.Sandboxing);
 
             if (!_modLoader.TryLoadModulesFrom(new ResourcePath("/Assemblies/"), Options.ContentModulePrefix))
             {
@@ -125,7 +125,6 @@ namespace Robust.Client
             _prototypeManager.Resync();
             _mapManager.Initialize();
             _entityManager.Initialize();
-            IoCManager.Resolve<IEntityLookup>().Initialize();
             _gameStateManager.Initialize();
             _placementManager.Initialize();
             _viewVariablesManager.Initialize();

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -109,6 +109,7 @@ 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/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

@@ -125,6 +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
         {
@@ -1355,7 +1367,7 @@ namespace Robust.Client.GameObjects
             if (map != MapId.Nullspace)
             {
                 Owner.EntityManager.EventBus.RaiseEvent(EventSource.Local,
-                    new RenderTreeRemoveSpriteMessage(this, map));
+                    new RenderTreeRemoveSpriteEvent(this, map));
             }
         }
 
@@ -2179,6 +2191,10 @@ namespace Robust.Client.GameObjects
                 return null;
             }
 
+            public void QueueDelete()
+            {
+            }
+
             public void Delete()
             {
             }
@@ -2193,10 +2209,12 @@ 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

@@ -2,11 +2,10 @@
 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
 {
@@ -24,6 +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();
@@ -34,48 +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;
         }
@@ -87,7 +81,7 @@ namespace Robust.Client.GameObjects
                 return;
             }
 
-            if(!remoteCall)
+            if (!remoteCall)
                 SendMessage(new CloseBoundInterfaceMessage(), uiKey);
             _openInterfaces.Remove(uiKey);
             boundUserInterface.Dispose();
@@ -95,7 +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);

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/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 +50,148 @@ 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);
+            SubscribeLocalEvent<SpriteComponent, EntMapIdChangedMessage>(SpriteMapChanged);
+            SubscribeLocalEvent<SpriteComponent, MoveEvent>(SpriteMoved);
+            SubscribeLocalEvent<SpriteComponent, EntParentChangedMessage>(SpriteParentChanged);
+            SubscribeLocalEvent<SpriteComponent, RenderTreeRemoveSpriteEvent>(RemoveSprite);
+
+            SubscribeLocalEvent<PointLightComponent, EntMapIdChangedMessage>(LightMapChanged);
+            SubscribeLocalEvent<PointLightComponent, MoveEvent>(LightMoved);
+            SubscribeLocalEvent<PointLightComponent, EntParentChangedMessage>(LightParentChanged);
+            SubscribeLocalEvent<PointLightComponent, PointLightRadiusChangedEvent>(PointLightRadiusChanged);
+            SubscribeLocalEvent<PointLightComponent, RenderTreeRemoveLightEvent>(RemoveLight);
         }
 
+        // 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, RenderTreeRemoveSpriteEvent 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 +199,27 @@ 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 +243,109 @@ 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();
@@ -290,9 +380,9 @@ namespace Robust.Client.GameObjects
         }
     }
 
-    internal struct RenderTreeRemoveSpriteMessage
+    internal class RenderTreeRemoveSpriteEvent : EntityEventArgs
     {
-        public RenderTreeRemoveSpriteMessage(SpriteComponent sprite, MapId map)
+        public RenderTreeRemoveSpriteEvent(SpriteComponent sprite, MapId map)
         {
             Sprite = sprite;
             Map = map;
@@ -302,9 +392,9 @@ namespace Robust.Client.GameObjects
         public MapId Map { get; }
     }
 
-    internal struct RenderTreeRemoveLightMessage
+    internal class RenderTreeRemoveLightEvent : EntityEventArgs
     {
-        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/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

@@ -183,6 +183,32 @@ namespace Robust.Client.Graphics.Clyde
             if (handles.filterHandle != 0) EFX.DeleteFilter(handles.filterHandle);
         }
 
+        public AudioStream LoadAudioRaw(short[] samples, int channels, int sampleRate)
+        {
+            var buffer = AL.GenBuffer();
+
+            unsafe
+            {
+                fixed (short* ptr = samples)
+                {
+                    AL.BufferData(
+                        buffer,
+                        channels == 1 ? ALFormat.Mono16 : ALFormat.Stereo16,
+                        (IntPtr) ptr,
+                        samples.Length * 2,
+                        sampleRate);
+                }
+            }
+
+            _checkAlError();
+
+            var handle = new ClydeHandle(_audioSampleBuffers.Count);
+            _audioSampleBuffers.Add(new LoadedAudioSample(buffer));
+            // ReSharper disable once PossibleLossOfFraction
+            var length = TimeSpan.FromSeconds(samples.Length / channels / (double) sampleRate);
+            return new AudioStream(handle, length, channels);
+        }
+
         public void SetMasterVolume(float newVolume)
         {
             AL.Listener(ALListenerf.Gain, _baseGain * newVolume);
@@ -439,6 +465,21 @@ namespace Robust.Client.Graphics.Clyde
                 _checkAlError();
             }
 
+            public void SetVolumeDirect(float decibels)
+            {
+                _checkDisposed();
+                var priorOcclusion = 1f;
+                if (!IsEfxSupported)
+                {
+                    AL.GetSource(SourceHandle, ALSourcef.Gain, out var priorGain);
+                    priorOcclusion = priorGain / _gain;
+                }
+
+                _gain = decibels;
+                AL.Source(SourceHandle, ALSourcef.Gain, _gain * priorOcclusion);
+                _checkAlError();
+            }
+
             public void SetOcclusion(float blocks)
             {
                 _checkDisposed();
@@ -747,6 +788,21 @@ namespace Robust.Client.Graphics.Clyde
                 _checkAlError();
             }
 
+            public void SetVolumeDirect(float masterVolumeDecay)
+            {
+                _checkDisposed();
+                var priorOcclusion = 1f;
+                if (!IsEfxSupported)
+                {
+                    AL.GetSource(SourceHandle!.Value, ALSourcef.Gain, out var priorGain);
+                    priorOcclusion = priorGain / _gain;
+                }
+
+                _gain = masterVolumeDecay;
+                AL.Source(SourceHandle!.Value, ALSourcef.Gain, _gain * priorOcclusion);
+                _checkAlError();
+            }
+
             public void SetPitch(float pitch)
             {
                 _checkDisposed();

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -248,6 +248,11 @@ namespace Robust.Client.Graphics.Clyde
             return new(default, default, 1, name);
         }
 
+        public AudioStream LoadAudioRaw(short[] samples, int channels, int sampleRate)
+        {
+            throw new NotImplementedException();
+        }
+
         public IClydeAudioSource CreateAudioSource(AudioStream stream)
         {
             return DummyAudioSource.Instance;
@@ -337,6 +342,11 @@ namespace Robust.Client.Graphics.Clyde
             {
                 // Nada.
             }
+
+            public void SetVolumeDirect(float masterVolumeDecay)
+            {
+                // Nada.
+            }
         }
 
         private sealed class DummyBufferedAudioSource : DummyAudioSource, IClydeBufferedAudioSource

Robust.Client/Graphics/IClydeAudio.cs

@@ -8,6 +8,7 @@ namespace Robust.Client.Graphics
         // AUDIO SYSTEM DOWN BELOW.
         AudioStream LoadAudioOggVorbis(Stream stream, string? name = null);
         AudioStream LoadAudioWav(Stream stream, string? name = null);
+        AudioStream LoadAudioRaw(short[] samples, int channels, int sampleRate);
 
         void SetMasterVolume(float newVolume);
 

Robust.Client/Graphics/IClydeAudioSource.cs

@@ -21,5 +21,6 @@ namespace Robust.Client.Graphics
         void SetOcclusion(float blocks);
         void SetPlaybackPosition(float seconds);
         void SetVelocity(Vector2 velocity);
+        void SetVolumeDirect(float masterVolumeDecay);
     }
 }

Robust.Client/Graphics/IRenderHandle.cs

@@ -4,7 +4,7 @@ using Robust.Shared.Maths;
 
 namespace Robust.Client.Graphics
 {
-    internal interface IRenderHandle
+    public interface IRenderHandle
     {
         DrawingHandleScreen DrawingHandleScreen { get; }
         DrawingHandleWorld DrawingHandleWorld { get; }

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/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

@@ -28,7 +28,7 @@ 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 +69,10 @@ 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;

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/UserInterface/Control.cs

@@ -463,7 +463,7 @@ namespace Robust.Client.UserInterface
         {
         }
 
-        internal virtual void DrawInternal(IRenderHandle renderHandle)
+        public virtual void DrawInternal(IRenderHandle renderHandle)
         {
             Draw(renderHandle.DrawingHandleScreen);
         }

Robust.Client/UserInterface/Controls/SpriteView.cs

@@ -41,7 +41,7 @@ namespace Robust.Client.UserInterface.Controls
             return (32, 32) * Scale;
         }
 
-        internal override void DrawInternal(IRenderHandle renderHandle)
+        public override void DrawInternal(IRenderHandle renderHandle)
         {
             if (Sprite == null || Sprite.Deleted)
             {

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.Server/BaseServer.cs

@@ -306,7 +306,6 @@ namespace Robust.Server
             // Call Init in game assemblies.
             _modLoader.BroadcastRunLevel(ModRunLevel.Init);
             _entityManager.Initialize();
-            IoCManager.Resolve<IEntityLookup>().Initialize();
 
             IoCManager.Resolve<ISerializationManager>().Initialize();
 
@@ -319,6 +318,7 @@ namespace Robust.Server
 
             IoCManager.Resolve<IServerConsoleHost>().Initialize();
             _entityManager.Startup();
+            IoCManager.Resolve<IEntityLookup>().Startup();
             _stateManager.Initialize();
             _scriptHost.Initialize();
 

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/GameObjects/Components/Actor/ActorComponent.cs

@@ -27,6 +27,7 @@ namespace Robust.Server.GameObjects
     ///     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; }
@@ -41,6 +42,7 @@ namespace Robust.Server.GameObjects
     ///     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; }

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;
 
@@ -49,7 +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);
         }
@@ -68,32 +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);
         }
     }
 
@@ -154,6 +141,7 @@ namespace Robust.Server.GameObjects
             {
                 _playerStateOverrides[session] = state;
             }
+
             _stateDirty = true;
         }
 
@@ -179,7 +167,6 @@ namespace Robust.Server.GameObjects
         }
 
 
-
         /// <summary>
         ///     Opens this interface for a specific client.
         /// </summary>

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

@@ -219,9 +219,7 @@ 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;
@@ -320,7 +318,12 @@ 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 +335,7 @@ 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/ServerEntityManager.cs

@@ -137,6 +137,7 @@ 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/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.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/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/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.Physics.cs

@@ -98,7 +98,6 @@ namespace Robust.Shared.GameObjects
                 if (_bodyType == value)
                     return;
 
-                var oldAnchored = _bodyType == BodyType.Static;
                 var oldType = _bodyType;
                 _bodyType = value;
 
@@ -121,14 +120,7 @@ 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));
-                }
             }
         }
 
@@ -900,35 +892,6 @@ 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
         {
@@ -1347,16 +1310,6 @@ namespace Robust.Shared.GameObjects
         }
     }
 
-    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>
@@ -1372,11 +1325,6 @@ 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/MapGridComponent.cs

@@ -52,6 +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/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;
@@ -66,25 +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
@@ -264,6 +261,7 @@ namespace Robust.Shared.GameObjects
             set
             {
                 var oldPosition = Coordinates;
+                _localPosition = value.Position;
 
                 if (value.EntityId != _parent)
                 {
@@ -271,7 +269,6 @@ namespace Robust.Shared.GameObjects
                     AttachParent(newEntity);
                 }
 
-                _localPosition = value.Position;
                 Dirty();
 
                 if (!DeferUpdates)
@@ -425,6 +422,28 @@ 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 />
@@ -572,7 +591,6 @@ namespace Robust.Shared.GameObjects
             // offset position from world to parent
             SetPosition(newParent.InvWorldMatrix.Transform(WorldPosition));
             _parent = newParentEnt.Uid;
-
             ChangeMapId(newConcrete.MapID);
 
             Owner.EntityManager.EventBus.RaiseLocalEvent(Owner.Uid, entMessage);
@@ -580,6 +598,7 @@ namespace Robust.Shared.GameObjects
 
             RebuildMatrices();
             Dirty();
+            GridID = GetGridIndex();
         }
 
         internal void ChangeMapId(MapId newMapId)

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/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();
@@ -288,6 +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))
@@ -458,6 +480,7 @@ namespace Robust.Shared.GameObjects
             var session = netMsg.Session;
             compMsg.Remote = true;
 
+#pragma warning disable 618
             var uid = netMsg.EntityUid;
             if (compMsg.Directed)
             {
@@ -471,6 +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>();
+            }
+        }
+    }
+}

Robust.Shared/GameObjects/EntitySystem.cs

@@ -18,7 +18,7 @@ namespace Robust.Shared.GameObjects
     ///     This class is instantiated by the <c>EntitySystemManager</c>, and any IoC Dependencies will be resolved.
     /// </remarks>
     [Reflect(false), PublicAPI]
-    public abstract class EntitySystem : IEntitySystem
+    public abstract partial class EntitySystem : IEntitySystem
     {
         [Dependency] protected readonly IEntityManager EntityManager = default!;
         [Dependency] protected readonly IComponentManager ComponentManager = default!;
@@ -40,47 +40,14 @@ namespace Robust.Shared.GameObjects
         public virtual void FrameUpdate(float frameTime) { }
 
         /// <inheritdoc />
-        public virtual void Shutdown() { }
+        public virtual void Shutdown()
+        {
+            ShutdownSubscriptions();
+        }
 
 
         #region Event Proxy
 
-        protected void SubscribeNetworkEvent<T>(EntityEventHandler<T> handler)
-            where T : notnull
-        {
-            EntityManager.EventBus.SubscribeEvent(EventSource.Network, this, handler);
-        }
-
-        protected void SubscribeNetworkEvent<T>(EntitySessionEventHandler<T> handler)
-            where T : notnull
-        {
-            EntityManager.EventBus.SubscribeSessionEvent(EventSource.Network, this, handler);
-        }
-
-        protected void SubscribeLocalEvent<T>(EntityEventHandler<T> handler)
-            where T : notnull
-        {
-            EntityManager.EventBus.SubscribeEvent(EventSource.Local, this, handler);
-        }
-
-        protected void SubscribeLocalEvent<T>(EntitySessionEventHandler<T> handler)
-            where T : notnull
-        {
-            EntityManager.EventBus.SubscribeSessionEvent(EventSource.Local, this, handler);
-        }
-
-        protected void UnsubscribeNetworkEvent<T>()
-            where T : notnull
-        {
-            EntityManager.EventBus.UnsubscribeEvent<T>(EventSource.Network, this);
-        }
-
-        protected void UnsubscribeLocalEvent<T>()
-            where T : notnull
-        {
-            EntityManager.EventBus.UnsubscribeEvent<T>(EventSource.Local, this);
-        }
-
         protected void RaiseLocalEvent<T>(T message) where T : notnull
         {
             EntityManager.EventBus.RaiseEvent(EventSource.Local, message);
@@ -120,28 +87,6 @@ namespace Robust.Shared.GameObjects
             return EntityManager.EventBus.AwaitEvent<T>(EventSource.Network, cancellationToken);
         }
 
-        protected void SubscribeLocalEvent<TComp, TEvent>(ComponentEventHandler<TComp, TEvent> handler)
-            where TComp : IComponent
-            where TEvent : EntityEventArgs
-        {
-            EntityManager.EventBus.SubscribeLocalEvent(handler);
-        }
-
-        [Obsolete("Use the overload without the handler argument.")]
-        protected void UnsubscribeLocalEvent<TComp, TEvent>(ComponentEventHandler<TComp, TEvent> handler)
-            where TComp : IComponent
-            where TEvent : EntityEventArgs
-        {
-            EntityManager.EventBus.UnsubscribeLocalEvent<TComp, TEvent>();
-        }
-
-        protected void UnsubscribeLocalEvent<TComp, TEvent>()
-            where TComp : IComponent
-            where TEvent : EntityEventArgs
-        {
-            EntityManager.EventBus.UnsubscribeLocalEvent<TComp, TEvent>();
-        }
-
         protected void RaiseLocalEvent<TEvent>(EntityUid uid, TEvent args, bool broadcast = true)
             where TEvent : EntityEventArgs
         {

Robust.Shared/GameObjects/EntitySystemMessages/EntMapIdChangedMessage.cs

@@ -2,7 +2,7 @@ using Robust.Shared.Map;
 
 namespace Robust.Shared.GameObjects
 {
-    public readonly struct EntMapIdChangedMessage
+    public class EntMapIdChangedMessage : EntityEventArgs
     {
         public EntMapIdChangedMessage(IEntity entity, MapId oldMapId)
         {

Robust.Shared/GameObjects/IComponent.cs

@@ -1,4 +1,5 @@
-using Robust.Shared.Network;
+using System;
+using Robust.Shared.Network;
 using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Timing;
@@ -105,6 +106,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <param name="message">Incoming event message.</param>
         /// <param name="component">The local component that sent the message.</param>
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         void HandleMessage(ComponentMessage message, IComponent? component);
 
         /// <summary>
@@ -113,6 +115,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="message">Incoming event message.</param>
         /// <param name="netChannel">The channel of the remote client that sent the message.</param>
         /// <param name="session">The session data for the player who sent this message. Null if this is a client.</param>
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         void HandleNetworkMessage(ComponentMessage message, INetChannel netChannel, ICommonSession? session = null);
 
         /// <summary>

Robust.Shared/GameObjects/IEntity.cs

@@ -161,6 +161,11 @@ namespace Robust.Shared.GameObjects
         /// <returns>The component, if it was found. Null otherwise.</returns>
         IComponent? GetComponentOrNull(Type type);
 
+        /// <summary>
+        ///     Queues this entity for deletion at the end of the tick.
+        /// </summary>
+        void QueueDelete();
+
         /// <summary>
         ///     Deletes this entity.
         /// </summary>
@@ -185,6 +190,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <param name="owner">Object that sent the event.</param>
         /// <param name="message">Message to send.</param>
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         void SendMessage(IComponent? owner, ComponentMessage message);
 
         /// <summary>
@@ -192,6 +198,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <param name="owner"></param>
         /// <param name="message">Message to send.</param>
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         void SendNetworkMessage(IComponent owner, ComponentMessage message, INetChannel? channel = null);
 
         /// <summary>

Robust.Shared/GameObjects/IEntityManager.cs

@@ -84,6 +84,10 @@ namespace Robust.Shared.GameObjects
 
         IEnumerable<IEntity> GetEntities();
 
+        public void QueueDeleteEntity(IEntity entity);
+
+        public void QueueDeleteEntity(EntityUid uid);
+
         /// <summary>
         /// Shuts-down and removes given <see cref="IEntity"/>. This is also broadcast to all clients.
         /// </summary>

Robust.Shared/GameObjects/IEntityNetworkManager.cs

@@ -34,6 +34,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="entity">Entity sending the message (also entity to send to).</param>
         /// <param name="component">Component that sent the message.</param>
         /// <param name="message">Message to send.</param>
+        [Obsolete("Component Messages are deprecated, use Entity Events instead.")]
         void SendComponentNetworkMessage(INetChannel? channel, IEntity entity, IComponent component,
             ComponentMessage message);
 

Robust.Shared/GameObjects/NetworkComponentMessage.cs

@@ -30,7 +30,9 @@ namespace Robust.Shared.GameObjects
         /// <summary>
         /// The message payload.
         /// </summary>
+#pragma warning disable 618
         public readonly ComponentMessage Message;
+#pragma warning restore 618
 
         /// <summary>
         /// If the message is from the client, the client's session.

Robust.Shared/GameObjects/Systems/CollisionWakeSystem.cs

@@ -12,14 +12,6 @@ namespace Robust.Shared.GameObjects
             SubscribeLocalEvent<CollisionWakeComponent, CollisionWakeStateMessage>(HandleCollisionWakeState);
         }
 
-        public override void Shutdown()
-        {
-            base.Shutdown();
-            UnsubscribeLocalEvent<PhysicsWakeMessage>();
-            UnsubscribeLocalEvent<PhysicsSleepMessage>();
-            UnsubscribeLocalEvent<CollisionWakeComponent, CollisionWakeStateMessage>();
-        }
-
         private void HandleWake(PhysicsWakeMessage message)
         {
             if (!message.Body.Owner.TryGetComponent<CollisionWakeComponent>(out var comp) || !comp.Enabled) return;

Robust.Shared/GameObjects/Systems/EntityLookup.cs

@@ -1,6 +1,8 @@
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using JetBrains.Annotations;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
@@ -12,7 +14,7 @@ namespace Robust.Shared.GameObjects
     {
         // Not an EntitySystem given EntityManager has a dependency on it which means it's just easier to IoC it for tests.
 
-        void Initialize();
+        void Startup();
 
         void Shutdown();
 
@@ -61,7 +63,8 @@ namespace Robust.Shared.GameObjects
         Box2 GetWorldAabbFromEntity(in IEntity ent);
     }
 
-    public class SharedEntityLookup : IEntityLookup, IEntityEventSubscriber
+    [UsedImplicitly]
+    public class EntityLookup : IEntityLookup, IEntityEventSubscriber
     {
         private readonly IEntityManager _entityManager;
         private readonly IMapManager _mapManager;
@@ -69,25 +72,32 @@ namespace Robust.Shared.GameObjects
         private readonly Dictionary<MapId, DynamicTree<IEntity>> _entityTreesPerMap = new();
 
         // Using stacks so we always use latest data (given we only run it once per entity).
-        private Stack<MoveEvent> _moveQueue = new();
-        private Stack<RotateEvent> _rotateQueue = new();
-        private Queue<EntMapIdChangedMessage> _mapChangeQueue = new();
+        private readonly Stack<MoveEvent> _moveQueue = new();
+        private readonly Stack<RotateEvent> _rotateQueue = new();
+        private readonly Queue<EntMapIdChangedMessage> _mapChangeQueue = new();
 
         /// <summary>
         /// Move and rotate events generate the same update so no point duplicating work in the same tick.
         /// </summary>
-        private HashSet<EntityUid> _handledThisTick = new();
+        private readonly HashSet<EntityUid> _handledThisTick = new();
 
         // TODO: Should combine all of the methods that check for IPhysBody and just use the one GetWorldAabbFromEntity method
 
-        public SharedEntityLookup(IEntityManager entityManager, IMapManager mapManager)
+        public bool Started { get; private set; } = false;
+
+        public EntityLookup(IEntityManager entityManager, IMapManager mapManager)
         {
             _entityManager = entityManager;
             _mapManager = mapManager;
         }
 
-        public void Initialize()
+        public void Startup()
         {
+            if (Started)
+            {
+                throw new InvalidOperationException("Startup() called multiple times.");
+            }
+
             var eventBus = _entityManager.EventBus;
             eventBus.SubscribeEvent<MoveEvent>(EventSource.Local, this, ev => _moveQueue.Push(ev));
             eventBus.SubscribeEvent<RotateEvent>(EventSource.Local, this, ev => _rotateQueue.Push(ev));
@@ -96,15 +106,27 @@ namespace Robust.Shared.GameObjects
             _entityManager.EntityStarted += HandleEntityStarted;
             _mapManager.MapCreated += HandleMapCreated;
             _mapManager.MapDestroyed += HandleMapDestroyed;
+            Started = true;
         }
 
         public void Shutdown()
         {
+            // If we haven't even started up, there's nothing to clean up then.
+            if (!Started)
+                return;
+
+            _moveQueue.Clear();
+            _rotateQueue.Clear();
+            _handledThisTick.Clear();
+            _mapChangeQueue.Clear();
+            _entityTreesPerMap.Clear();
+
             _entityManager.EventBus.UnsubscribeEvents(this);
             _entityManager.EntityDeleted -= HandleEntityDeleted;
             _entityManager.EntityStarted -= HandleEntityStarted;
             _mapManager.MapCreated -= HandleMapCreated;
             _mapManager.MapDestroyed -= HandleMapDestroyed;
+            Started = false;
         }
 
         private void HandleEntityDeleted(object? sender, EntityUid uid)
@@ -193,14 +215,14 @@ namespace Robust.Shared.GameObjects
         /// <inheritdoc />
         public IEnumerable<IEntity> GetEntitiesIntersecting(MapId mapId, Box2 position, bool approximate = false)
         {
-            if (mapId == MapId.Nullspace)
+            if (!_entityTreesPerMap.TryGetValue(mapId, out var mapTree))
             {
                 return Enumerable.Empty<IEntity>();
             }
 
             var list = new List<IEntity>();
 
-            _entityTreesPerMap[mapId].QueryAabb(ref list, (ref List<IEntity> list, in IEntity ent) =>
+            mapTree.QueryAabb(ref list, (ref List<IEntity> list, in IEntity ent) =>
             {
                 if (!ent.Deleted)
                 {

Robust.Shared/GameObjects/Systems/OccluderSystem.cs

@@ -53,6 +53,7 @@ namespace Robust.Shared.GameObjects
         public override void Shutdown()
         {
             base.Shutdown();
+
             _mapManager.MapCreated -= OnMapCreated;
             _mapManager.MapDestroyed -= OnMapDestroyed;
             _mapManager.OnGridCreated -= OnGridCreated;

Robust.Shared/GameObjects/Systems/SharedGridTraversalSystem.cs

@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Robust.Shared.Containers;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
@@ -12,55 +11,63 @@ namespace Robust.Shared.GameObjects
     {
         [Dependency] private readonly IMapManager _mapManager = default!;
 
-        private Queue<MoveEvent> _queuedMoveEvents = new();
-
         public override void Initialize()
         {
             base.Initialize();
-            SubscribeLocalEvent<MoveEvent>(QueueMoveEvent);
+            SubscribeLocalEvent<MoveEvent>(HandleMove);
         }
 
-        public override void Shutdown()
+        private void HandleMove(MoveEvent moveEvent)
         {
-            base.Shutdown();
-            UnsubscribeLocalEvent<MoveEvent>();
-        }
+            var entity = moveEvent.Sender;
 
-        public override void Update(float frameTime)
-        {
-            base.Update(frameTime);
-            while (_queuedMoveEvents.Count > 0)
+            if (entity.Deleted ||
+                entity.HasComponent<IMapComponent>() ||
+                entity.HasComponent<IMapGridComponent>() ||
+                entity.IsInContainer())
             {
-                var moveEvent = _queuedMoveEvents.Dequeue();
-                var entity = moveEvent.Sender;
+                return;
+            }
 
-                if (entity.Deleted || !entity.HasComponent<PhysicsComponent>() || entity.IsInContainer()) continue;
+            var transform = entity.Transform;
 
-                var transform = entity.Transform;
-                // Change parent if necessary
-                // Given islands will probably have a bunch of static bodies in them then we'll verify velocities first as it's way cheaper
-
-                // This shoouullddnnn'''tt de-parent anything in a container because none of that should have physics applied to it.
-                if (_mapManager.TryFindGridAt(transform.MapID, moveEvent.NewPosition.ToMapPos(EntityManager), out var grid) &&
-                    grid.GridEntityId.IsValid() &&
-                    grid.GridEntityId != entity.Uid)
+            // Change parent if necessary
+            if (_mapManager.TryFindGridAt(transform.MapID, moveEvent.NewPosition.ToMapPos(EntityManager), out var grid) &&
+                grid.GridEntityId.IsValid() &&
+                grid.GridEntityId != entity.Uid)
+            {
+                // Some minor duplication here with AttachParent but only happens when going on/off grid so not a big deal ATM.
+                if (grid.Index != transform.GridID)
                 {
-                    // Also this may deparent if 2 entities are parented but not using containers so fix that
-                    if (grid.Index != transform.GridID)
-                    {
-                        transform.AttachParent(EntityManager.GetEntity(grid.GridEntityId));
-                    }
+                    transform.AttachParent(EntityManager.GetEntity(grid.GridEntityId));
+                    RaiseLocalEvent(entity.Uid, new ChangedGridMessage(entity, transform.GridID, grid.Index));
                 }
-                else
+            }
+            else
+            {
+                var oldGridId = transform.GridID;
+
+                // Attach them to map / they are on an invalid grid
+                if (oldGridId != GridId.Invalid)
                 {
                     transform.AttachParent(_mapManager.GetMapEntity(transform.MapID));
+                    RaiseLocalEvent(entity.Uid, new ChangedGridMessage(entity, oldGridId, GridId.Invalid));
                 }
             }
         }
+    }
 
-        private void QueueMoveEvent(MoveEvent moveEvent)
+    public sealed class ChangedGridMessage : EntityEventArgs
+    {
+        public IEntity Entity;
+        public GridId OldGrid;
+        public GridId NewGrid;
+
+        public ChangedGridMessage(IEntity entity, GridId oldGrid, GridId newGrid)
         {
-            _queuedMoveEvents.Enqueue(moveEvent);
+            Entity = entity;
+            OldGrid = oldGrid;
+            NewGrid = newGrid;
         }
     }
 }

Robust.Shared/GameObjects/Systems/SharedPhysicsSystem.cs

@@ -168,14 +168,6 @@ namespace Robust.Shared.GameObjects
 
             _mapManager.MapCreated -= HandleMapCreated;
             _mapManager.MapDestroyed -= HandleMapDestroyed;
-
-            UnsubscribeLocalEvent<PhysicsUpdateMessage>();
-            UnsubscribeLocalEvent<PhysicsWakeMessage>();
-            UnsubscribeLocalEvent<PhysicsSleepMessage>();
-            UnsubscribeLocalEvent<EntMapIdChangedMessage>();
-
-            UnsubscribeLocalEvent<EntInsertedIntoContainerMessage>();
-            UnsubscribeLocalEvent<EntRemovedFromContainerMessage>();
         }
 
         private void HandleMapCreated(object? sender, MapEventArgs eventArgs)

Robust.Shared/GameObjects/Systems/SnapGridSystem.cs

@@ -21,16 +21,6 @@ namespace Robust.Shared.GameObjects
             SubscribeLocalEvent<SnapGridComponent, MoveEvent>(HandleMoveEvent);
         }
 
-        /// <inheritdoc />
-        public override void Shutdown()
-        {
-            base.Shutdown();
-
-            UnsubscribeLocalEvent<SnapGridComponent, ComponentStartup>();
-            UnsubscribeLocalEvent<SnapGridComponent, ComponentShutdown>();
-            UnsubscribeLocalEvent<SnapGridComponent, MoveEvent>();
-        }
-
         private void HandleComponentStartup(EntityUid uid, SnapGridComponent component, ComponentStartup args)
         {
             var transform = ComponentManager.GetComponent<ITransformComponent>(uid);

Robust.Shared/Input/InputContextContainer.cs

@@ -14,6 +14,11 @@ namespace Robust.Shared.Input
         /// </summary>
         IInputCmdContext ActiveContext { get; }
 
+        /// <summary>
+        ///     Puts context switches 'on hold'. When set to false, the last deferred context switch is executed, if any.
+        /// </summary>
+        bool DeferringEnabled { get; set; }
+
         /// <summary>
         ///     This event is raised when ever the Active Context is changed.
         /// </summary>
@@ -65,6 +70,7 @@ namespace Robust.Shared.Input
 
         /// <summary>
         ///     Sets the context with the given unique name as the Active context.
+        ///     This *may* be deferred if during input handling, and if multiple context switches are deferred, only the last 'counts'.
         /// </summary>
         /// <param name="uniqueName">Unique name of the context to set as active.</param>
         void SetActiveContext(string uniqueName);
@@ -82,17 +88,42 @@ namespace Robust.Shared.Input
         public event EventHandler<ContextChangedEventArgs>? ContextChanged;
 
         private readonly Dictionary<string, InputCmdContext> _contexts = new();
+        // Random scribble here:
+        // InputManager r/n feeds the first active context using DefaultContextName
+        // This is why SetActiveContext needs to be careful to *not* defer the switch if there's no context,
+        //  or else the client instantly crashes because there's no context on startup
         private InputCmdContext _activeContext = default!;
+        /// <summary>
+        ///     This is used to hold a pending context switch, because someone decided that:
+        ///      + Reentrant input events were illegal
+        ///       and
+        ///      + Context switches ought to generate input events
+        ///     This prevents the inevitable errors this caused from input events that switch contexts,
+        ///      by deferring the context switches until we're definitely out of input event code.
+        /// </summary>
+        private InputCmdContext? _deferredContextSwitch = null;
 
         /// <inheritdoc />
-        public IInputCmdContext ActiveContext
+        public IInputCmdContext ActiveContext => _activeContext;
+
+        private bool _deferringEnabled = false;
+
+        /// <inheritdoc />
+        public bool DeferringEnabled
         {
-            get => _activeContext;
-            private set
-            {
-                var args = new ContextChangedEventArgs(_activeContext, value);
-                _activeContext = (InputCmdContext) value;
-                ContextChanged?.Invoke(this, args);
+            get => _deferringEnabled;
+            set {
+                // Must be first because _setActiveContextImmediately triggers input events.
+                _deferringEnabled = value;
+                if (!value)
+                {
+                    if (_deferredContextSwitch != null)
+                    {
+                        var icc = _deferredContextSwitch;
+                        _deferredContextSwitch = null;
+                        _setActiveContextImmediately(icc);
+                    }
+                }
             }
         }
 
@@ -179,7 +210,21 @@ namespace Robust.Shared.Input
         /// <inheritdoc />
         public void SetActiveContext(string uniqueName)
         {
-            ActiveContext = _contexts[uniqueName];
+            if (!DeferringEnabled)
+            {
+                _setActiveContextImmediately(_contexts[uniqueName]);
+            }
+            else
+            {
+                _deferredContextSwitch = _contexts[uniqueName];
+            }
+        }
+
+        private void _setActiveContextImmediately(InputCmdContext icc)
+        {
+            var args = new ContextChangedEventArgs(_activeContext, icc);
+            _activeContext = icc;
+            ContextChanged?.Invoke(this, args);
         }
     }
 

Robust.Shared/Network/Messages/MsgEntity.cs

@@ -23,7 +23,9 @@ namespace Robust.Shared.Network.Messages
         public EntityMessageType Type { get; set; }
 
         public EntityEventArgs SystemMessage { get; set; }
+#pragma warning disable 618
         public ComponentMessage ComponentMessage { get; set; }
+#pragma warning restore 618
 
         public EntityUid EntityUid { get; set; }
         public uint NetId { get; set; }
@@ -55,7 +57,9 @@ namespace Robust.Shared.Network.Messages
                     var serializer = IoCManager.Resolve<IRobustSerializer>();
                     int length = buffer.ReadVariableInt32();
                     using var stream = buffer.ReadAlignedMemory(length);
+#pragma warning disable 618
                     ComponentMessage = serializer.Deserialize<ComponentMessage>(stream);
+#pragma warning restore 618
                 }
                     break;
             }

Robust.Shared/Physics/BroadPhase/SharedBroadPhaseSystem.cs

@@ -218,13 +218,7 @@ namespace Robust.Shared.Physics.Broadphase
         public override void Shutdown()
         {
             base.Shutdown();
-            UnsubscribeLocalEvent<CollisionChangeMessage>();
-            UnsubscribeLocalEvent<MoveEvent>();
-            UnsubscribeLocalEvent<RotateEvent>();
-            UnsubscribeLocalEvent<EntMapIdChangedMessage>();
-            UnsubscribeLocalEvent<EntInsertedIntoContainerMessage>();
-            UnsubscribeLocalEvent<EntRemovedFromContainerMessage>();
-            UnsubscribeLocalEvent<FixtureUpdateMessage>();
+
             _mapManager.OnGridCreated -= HandleGridCreated;
             _mapManager.OnGridRemoved -= HandleGridRemoval;
             _mapManager.MapCreated -= HandleMapCreated;

Robust.Shared/Serialization/TypeSerializers/Implementations/Custom/Prototype/List/PrototypeIdListSerializer.cs

@@ -105,7 +105,7 @@ namespace Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Pro
             bool skipHook,
             ISerializationContext? context)
         {
-            return new();
+            return new(source);
         }
     }
 }

Robust.Shared/Utility/StreamExt.cs

@@ -44,7 +44,7 @@ namespace Robust.Shared.Utility
         }
 
         /// <exception cref="EndOfStreamException">
-        /// Thrown if not exactly <paramref name="amount"/> bytes could be read.
+        /// Thrown if not exactly <paramref name="buffer.Length"/> bytes could be read.
         /// </exception>
         public static void ReadExact(this Stream stream, Span<byte> buffer)
         {

Robust.UnitTesting/RobustUnitTest.cs

@@ -73,7 +73,7 @@ namespace Robust.UnitTesting
                 entMan.Startup();
             }
 
-            IoCManager.Resolve<IEntityLookup>().Initialize();
+            IoCManager.Resolve<IEntityLookup>().Startup();
             var mapMan = IoCManager.Resolve<IMapManager>();
             mapMan.Initialize();
             mapMan.Startup();

Robust.UnitTesting/Server/RobustServerSimulation.cs

@@ -175,7 +175,7 @@ namespace Robust.UnitTesting.Server
             //Tier 2: Simulation
             container.Register<IEntityManager, EntityManager>();
             container.Register<IMapManager, MapManager>();
-            container.Register<IEntityLookup, SharedEntityLookup>();
+            container.Register<IEntityLookup, EntityLookup>();
             container.Register<ISerializationManager, SerializationManager>();
             container.Register<IComponentManager, ComponentManager>();
             container.Register<IPrototypeManager, PrototypeManager>();
@@ -203,9 +203,9 @@ namespace Robust.UnitTesting.Server
 
             var entityMan = container.Resolve<IEntityManager>();
             entityMan.Initialize();
-            IoCManager.Resolve<IEntityLookup>().Initialize();
             _systemDelegate?.Invoke(container.Resolve<IEntitySystemManager>());
             entityMan.Startup();
+            IoCManager.Resolve<IEntityLookup>().Startup();
 
             var mapManager = container.Resolve<IMapManager>();
             mapManager.Initialize();