Network View Bubble (#1629)

* Adds barbones culling.

* Visibility culling and recursive parent ent additions.
DebugEntityNetView improvements.
Visibility moved from session to eyecomponent.

* Multiple viewport support.

* Perf improvements.

* Removed old netbubble system from ServerEntityManager.
Supports old NaN system for entities leaving view.
Supports old SendFullMap optimization for anchored, non-updating Entities.

* Fixes size of netView box.

* Remove empty EntityManager.Update method.
Switching ViewCulling back to PLINQ.

Resources/Shaders/Internal/fov-lighting.swsl

@@ -28,5 +28,10 @@ void fragment()
 
     highp float occlusion = ChebyshevUpperBound(occlDist, ourDist);
 
+    if (occlusion >= 1.0)
+    {
+        discard;
+    }
+
     COLOR = vec4(0.0, 0.0, 0.0, 1.0 - occlusion);
 }

Robust.Client/Audio/Midi/MidiManager.cs

@@ -11,7 +11,6 @@ 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;
@@ -321,6 +320,11 @@ namespace Robust.Client.Audio.Midi
                             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

Robust.Client/ClientIoC.cs

@@ -27,8 +27,6 @@ using Robust.Shared.Network;
 using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
-using Robust.Shared.Serialization;
-using Robust.Shared.Serialization.Manager;
 
 namespace Robust.Client
 {
@@ -66,8 +64,6 @@ namespace Robust.Client
             IoCManager.Register<IDiscordRichPresence, DiscordRichPresence>();
             IoCManager.Register<IClientConsoleHost, ClientConsoleHost>();
             IoCManager.Register<IConsoleHost, ClientConsoleHost>();
-            IoCManager.Register<IFontManager, FontManager>();
-            IoCManager.Register<IFontManagerInternal, FontManager>();
             IoCManager.Register<IMidiManager, MidiManager>();
             IoCManager.Register<IAuthManager, AuthManager>();
             switch (mode)
@@ -94,8 +90,9 @@ namespace Robust.Client
                     throw new ArgumentOutOfRangeException();
             }
 
+            IoCManager.Register<IFontManager, FontManager>();
+            IoCManager.Register<IFontManagerInternal, FontManager>();
             IoCManager.Register<IEyeManager, EyeManager>();
-
             IoCManager.Register<IPlacementManager, PlacementManager>();
             IoCManager.Register<IOverlayManager, OverlayManager>();
             IoCManager.Register<IOverlayManagerInternal, OverlayManager>();

Robust.Client/Console/Commands/MonitorCommands.cs

@@ -0,0 +1,44 @@
+using System.Linq;
+using JetBrains.Annotations;
+using Robust.Client.Graphics;
+using Robust.Shared.Console;
+using Robust.Shared.IoC;
+
+namespace Robust.Client.Console.Commands
+{
+    [UsedImplicitly]
+    public sealed class LsMonitorCommand : IConsoleCommand
+    {
+        public string Command => "lsmonitor";
+        public string Description => "";
+        public string Help => "";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            var clyde = IoCManager.Resolve<IClyde>();
+
+            foreach (var monitor in clyde.EnumerateMonitors())
+            {
+                shell.WriteLine(
+                    $"[{monitor.Id}] {monitor.Name}: {monitor.Size.X}x{monitor.Size.Y}@{monitor.RefreshRate}Hz");
+            }
+        }
+    }
+
+    [UsedImplicitly]
+    public sealed class SetMonitorCommand : IConsoleCommand
+    {
+        public string Command => "setmonitor";
+        public string Description => "";
+        public string Help => "Usage: setmonitor <id>";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            var clyde = IoCManager.Resolve<IClyde>();
+
+            var id = int.Parse(args[0]);
+            var monitor = clyde.EnumerateMonitors().Single(m => m.Id == id);
+            clyde.SetWindowMonitor(monitor);
+        }
+    }
+}

Robust.Client/Debugging/DebugDrawing.cs

@@ -1,8 +1,9 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
 using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
@@ -41,14 +42,14 @@ namespace Robust.Client.Debugging
 
                 _debugColliders = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<PhysicsOverlay>())
                 {
                     _overlayManager.AddOverlay(new PhysicsOverlay(_componentManager, _eyeManager,
                         _prototypeManager, _inputManager, _physicsManager));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(PhysicsOverlay));
+                    _overlayManager.RemoveOverlay<PhysicsOverlay>();
                 }
             }
         }
@@ -66,13 +67,13 @@ namespace Robust.Client.Debugging
 
                 _debugPositions = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<EntityPositionOverlay>())
                 {
                     _overlayManager.AddOverlay(new EntityPositionOverlay(_entityManager, _eyeManager));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(EntityPositionOverlay));
+                    _overlayManager.RemoveOverlay<EntityPositionOverlay>();
                 }
             }
         }
@@ -91,8 +92,8 @@ namespace Robust.Client.Debugging
             private Vector2 _hoverStartScreen = Vector2.Zero;
             private List<IPhysBody> _hoverBodies = new();
 
+
             public PhysicsOverlay(IComponentManager compMan, IEyeManager eyeMan, IPrototypeManager protoMan, IInputManager inputManager, IPhysicsManager physicsManager)
-                : base(nameof(PhysicsOverlay))
             {
                 _componentManager = compMan;
                 _eyeManager = eyeMan;
@@ -160,6 +161,8 @@ namespace Robust.Client.Debugging
                 if (viewport.IsEmpty()) return;
 
                 var mapId = _eyeManager.CurrentMap;
+                var sleepThreshold = IoCManager.Resolve<IConfigurationManager>().GetCVar(CVars.TimeToSleep);
+                var colorEdge = Color.Red.WithAlpha(0.33f);
 
                 foreach (var physBody in EntitySystem.Get<SharedBroadPhaseSystem>().GetCollidingEntities(mapId, viewport))
                 {
@@ -169,9 +172,6 @@ namespace Robust.Client.Debugging
                     var worldBox = physBody.GetWorldAABB();
                     if (worldBox.IsEmpty()) continue;
 
-                    var colorEdge = Color.Red.WithAlpha(0.33f);
-                    var sleepThreshold = IoCManager.Resolve<IConfigurationManager>().GetCVar(CVars.TimeToSleep);
-
                     foreach (var fixture in physBody.Fixtures)
                     {
                         var shape = fixture.Shape;
@@ -193,9 +193,9 @@ namespace Robust.Client.Debugging
             {
                 var baseLine = new Vector2(pos.X, font.GetAscent(1) + pos.Y);
 
-                foreach (var chr in str)
+                foreach (var rune in str.EnumerateRunes())
                 {
-                    var advance = font.DrawChar(handle, chr, baseLine, 1, Color.White);
+                    var advance = font.DrawChar(handle, rune, baseLine, 1, Color.White);
                     baseLine += new Vector2(advance, 0);
                 }
             }
@@ -265,7 +265,7 @@ namespace Robust.Client.Debugging
 
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public EntityPositionOverlay(IEntityManager entityManager, IEyeManager eyeManager) : base(nameof(EntityPositionOverlay))
+            public EntityPositionOverlay(IEntityManager entityManager, IEyeManager eyeManager)
             {
                 _entityManager = entityManager;
                 _eyeManager = eyeManager;

Robust.Client/Debugging/DebugDrawingManager.cs

@@ -1,10 +1,11 @@
-using Robust.Shared.IoC;
+using Robust.Shared.IoC;
 using Robust.Shared.Network.Messages;
 using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
+using Robust.Shared.Enums;
 using Robust.Shared.Network;
 
 namespace Robust.Client.Debugging
@@ -38,13 +39,13 @@ namespace Robust.Client.Debugging
 
                 _debugDrawRays = value;
 
-                if (value)
+                if (value && !_overlayManager.HasOverlay<DebugDrawRayOverlay>())
                 {
                     _overlayManager.AddOverlay(new DebugDrawRayOverlay(this));
                 }
                 else
                 {
-                    _overlayManager.RemoveOverlay(nameof(DebugDrawRayOverlay));
+                    _overlayManager.RemoveOverlay<DebugDrawRayOverlay>();
                 }
             }
         }
@@ -81,7 +82,7 @@ namespace Robust.Client.Debugging
             private readonly DebugDrawingManager _owner;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public DebugDrawRayOverlay(DebugDrawingManager owner) : base(nameof(DebugDrawRayOverlay))
+            public DebugDrawRayOverlay(DebugDrawingManager owner)
             {
                 _owner = owner;
             }

Robust.Client/Debugging/DebugPhysicsSystem.cs

@@ -24,6 +24,7 @@
 
 using System;
 using Robust.Client.Graphics;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -55,7 +56,7 @@ namespace Robust.Client.Debugging
                     IoCManager.Resolve<IOverlayManager>().AddOverlay(new PhysicsDebugOverlay(this));
 
                 if (value == PhysicsDebugFlags.None)
-                    IoCManager.Resolve<IOverlayManager>().RemoveOverlay(nameof(PhysicsDebugOverlay));
+                    IoCManager.Resolve<IOverlayManager>().RemoveOverlay(typeof(PhysicsDebugOverlay));
 
                 _flags = value;
             }
@@ -119,7 +120,7 @@ namespace Robust.Client.Debugging
 
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-        public PhysicsDebugOverlay(DebugPhysicsSystem system) : base(nameof(PhysicsDebugOverlay))
+        public PhysicsDebugOverlay(DebugPhysicsSystem system)
         {
             _physics = system;
         }

Robust.Client/GameController.cs

@@ -1,5 +1,6 @@
-using System;
+using System;
 using System.IO;
+using System.Management;
 using System.Net;
 using System.Threading.Tasks;
 using Robust.Client.Audio.Midi;
@@ -80,6 +81,74 @@ namespace Robust.Client
         }
 
         public bool Startup(Func<ILogHandler>? logHandlerFactory = null)
+        {
+            if (!StartupSystemSplash(logHandlerFactory))
+                return false;
+
+            // 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(!_disableAssemblyLoadContext);
+            _modLoader.SetEnableSandboxing(true);
+
+            if (!_modLoader.TryLoadModulesFrom(new ResourcePath("/Assemblies/"), "Content."))
+            {
+                Logger.Fatal("Errors while loading content assemblies.");
+                return false;
+            }
+
+            foreach (var loadedModule in _modLoader.LoadedModules)
+            {
+                _configurationManager.LoadCVarsFromAssembly(loadedModule);
+            }
+
+            IoCManager.Resolve<ISerializationManager>().Initialize();
+
+            // Call Init in game assemblies.
+            _modLoader.BroadcastRunLevel(ModRunLevel.PreInit);
+            _modLoader.BroadcastRunLevel(ModRunLevel.Init);
+
+            _resourceCache.PreloadTextures();
+            _userInterfaceManager.Initialize();
+            _networkManager.Initialize(false);
+            IoCManager.Resolve<INetConfigurationManager>().SetupNetworking();
+            _serializer.Initialize();
+            _inputManager.Initialize();
+            _console.Initialize();
+            _prototypeManager.Initialize();
+            _prototypeManager.LoadDirectory(new ResourcePath(@"/Prototypes/"));
+            _prototypeManager.Resync();
+            _mapManager.Initialize();
+            _entityManager.Initialize();
+            _gameStateManager.Initialize();
+            _placementManager.Initialize();
+            _viewVariablesManager.Initialize();
+            _scriptClient.Initialize();
+
+            _client.Initialize();
+            _discord.Initialize();
+            _modLoader.BroadcastRunLevel(ModRunLevel.PostInit);
+
+            if (_commandLineArgs?.Username != null)
+            {
+                _client.PlayerNameOverride = _commandLineArgs.Username;
+            }
+
+            _authManager.LoadFromEnv();
+
+            GC.Collect();
+
+            _clyde.Ready();
+
+            if ((_commandLineArgs?.Connect == true || _commandLineArgs?.Launcher == true)
+                && LaunchState.ConnectEndpoint != null)
+            {
+                _client.ConnectToServer(LaunchState.ConnectEndpoint);
+            }
+
+            return true;
+        }
+
+        private bool StartupSystemSplash(Func<ILogHandler>? logHandlerFactory)
         {
             ReadInitialLaunchState();
 
@@ -119,6 +188,8 @@ namespace Robust.Client
                 _configurationManager.OverrideConVars(_commandLineArgs.CVars);
             }
 
+            ProfileOptSetup.Setup(_configurationManager);
+
             _resourceCache.Initialize(LoadConfigAndUserData ? userDataDir : null);
 
             ProgramShared.DoMounts(_resourceCache, _commandLineArgs?.MountOptions, "Content.Client", _loaderArgs != null);
@@ -129,6 +200,13 @@ namespace Robust.Client
                 _modLoader.VerifierExtraLoadHandler = VerifierExtraLoadHandler;
             }
 
+            _clyde.TextEntered += TextEntered;
+            _clyde.MouseMove += MouseMove;
+            _clyde.KeyUp += KeyUp;
+            _clyde.KeyDown += KeyDown;
+            _clyde.MouseWheel += MouseWheel;
+            _clyde.CloseWindow += Shutdown;
+
             // Bring display up as soon as resources are mounted.
             if (!_clyde.Initialize())
             {
@@ -137,65 +215,7 @@ namespace Robust.Client
 
             _clyde.SetWindowTitle("Space Station 14");
 
-            _fontManager.Initialize();
-
-            // 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(!_disableAssemblyLoadContext);
-            _modLoader.SetEnableSandboxing(true);
-
-            if (!_modLoader.TryLoadModulesFrom(new ResourcePath("/Assemblies/"), "Content."))
-            {
-                Logger.Fatal("Errors while loading content assemblies.");
-                return false;
-            }
-
-            foreach (var loadedModule in _modLoader.LoadedModules)
-            {
-                _configurationManager.LoadCVarsFromAssembly(loadedModule);
-            }
-
-            IoCManager.Resolve<ISerializationManager>().Initialize();
-
-            // Call Init in game assemblies.
-            _modLoader.BroadcastRunLevel(ModRunLevel.PreInit);
-            _modLoader.BroadcastRunLevel(ModRunLevel.Init);
-
-            _userInterfaceManager.Initialize();
-            _networkManager.Initialize(false);
-            IoCManager.Resolve<INetConfigurationManager>().SetupNetworking();
-            _serializer.Initialize();
-            _inputManager.Initialize();
-            _console.Initialize();
-            _prototypeManager.Initialize();
-            _prototypeManager.LoadDirectory(new ResourcePath(@"/Prototypes/"));
-            _prototypeManager.Resync();
-            _mapManager.Initialize();
-            _entityManager.Initialize();
-            _gameStateManager.Initialize();
-            _placementManager.Initialize();
-            _viewVariablesManager.Initialize();
-            _scriptClient.Initialize();
-
-            _client.Initialize();
-            _discord.Initialize();
-            _modLoader.BroadcastRunLevel(ModRunLevel.PostInit);
-
-            if (_commandLineArgs?.Username != null)
-            {
-                _client.PlayerNameOverride = _commandLineArgs.Username;
-            }
-
-            _authManager.LoadFromEnv();
-
-            _clyde.Ready();
-
-            if ((_commandLineArgs?.Connect == true || _commandLineArgs?.Launcher == true)
-                && LaunchState.ConnectEndpoint != null)
-            {
-                _client.ConnectToServer(LaunchState.ConnectEndpoint);
-            }
-
+            _fontManager.SetFontDpi((uint) _configurationManager.GetCVar(CVars.DisplayFontDpi));
             return true;
         }
 
@@ -272,17 +292,13 @@ namespace Robust.Client
             _modLoader.BroadcastUpdate(ModUpdateLevel.PreEngine, frameEventArgs);
             _timerManager.UpdateTimers(frameEventArgs);
             _taskManager.ProcessPendingTasks();
-            _userInterfaceManager.Update(frameEventArgs);
 
+            // GameStateManager is in full control of the simulation update.
             if (_client.RunLevel >= ClientRunLevel.Connected)
             {
-                _componentManager.CullRemovedComponents();
                 _gameStateManager.ApplyGameState();
-                _entityManager.Update(frameEventArgs.DeltaSeconds);
-                _playerManager.Update(frameEventArgs.DeltaSeconds);
             }
 
-            _stateManager.Update(frameEventArgs);
             _modLoader.BroadcastUpdate(ModUpdateLevel.PostEngine, frameEventArgs);
         }
 

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -212,12 +212,6 @@ namespace Robust.Client.GameObjects
             return entity;
         }
 
-        /// <inheritdoc />
-        public override IEntity SpawnEntityNoMapInit(string? protoName, EntityCoordinates coordinates)
-        {
-            return SpawnEntity(protoName, coordinates);
-        }
-
         protected override EntityUid GenerateEntityUid()
         {
             return new(_nextClientEntityUid++);

Robust.Client/GameObjects/ClientEntityNetworkManager.cs

@@ -34,7 +34,7 @@ namespace Robust.Client.GameObjects
             _networkManager.RegisterNetMessage<MsgEntity>(MsgEntity.NAME, HandleEntityNetworkMessage);
         }
 
-        public void Update()
+        public void TickUpdate()
         {
             while (_queue.Count != 0 && _queue.Peek().msg.SourceTick <= _gameStateManager.CurServerTick)
             {
@@ -45,12 +45,12 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntitySystemMessage message)
+        public void SendSystemNetworkMessage(EntityEventArgs message)
         {
             SendSystemNetworkMessage(message, default(uint));
         }
 
-        public void SendSystemNetworkMessage(EntitySystemMessage message, uint sequence)
+        public void SendSystemNetworkMessage(EntityEventArgs message, uint sequence)
         {
             var msg = _networkManager.CreateNetMessage<MsgEntity>();
             msg.Type = EntityMessageType.SystemMessage;
@@ -62,7 +62,7 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntitySystemMessage message, INetChannel channel)
+        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel channel)
         {
             throw new NotSupportedException();
         }

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

@@ -1,4 +1,4 @@
-using Robust.Client.Graphics;
+using Robust.Client.Graphics;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
@@ -152,6 +152,7 @@ namespace Robust.Client.GameObjects
             Zoom = state.Zoom;
             Offset = state.Offset;
             Rotation = state.Rotation;
+            VisibilityMask = state.VisibilityMask;
         }
 
         public override void OnRemove()

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
@@ -19,6 +19,7 @@ using Robust.Shared.Reflection;
 using Robust.Shared.Serialization;
 using Robust.Shared.Serialization.Manager;
 using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
@@ -36,13 +37,13 @@ namespace Robust.Client.GameObjects
         private bool _visible = true;
 
         [ViewVariables(VVAccess.ReadWrite)]
-        public bool Visible
+        public override bool Visible
         {
             get => _visible;
             set => _visible = value;
         }
 
-        [DataFieldWithConstant("drawdepth", typeof(DrawDepthTag))]
+        [DataField("drawdepth", customTypeSerializer: typeof(ConstantSerializer<DrawDepthTag>))]
         private int drawDepth = DrawDepthTag.Default;
 
         /// <summary>
@@ -2084,6 +2085,7 @@ namespace Robust.Client.GameObjects
             public IEntityManager EntityManager { get; } = null!;
             public string Name { get; set; } = string.Empty;
             public EntityUid Uid { get; } = EntityUid.Invalid;
+            EntityLifeStage IEntity.LifeStage { get => _lifeStage; set => _lifeStage = value; }
             public bool Initialized { get; } = false;
             public bool Initializing { get; } = false;
             public bool Deleted { get; } = true;
@@ -2100,6 +2102,7 @@ namespace Robust.Client.GameObjects
             public IMetaDataComponent MetaData { get; } = null!;
 
             private Dictionary<Type, IComponent> _components = new();
+            private EntityLifeStage _lifeStage;
 
             public T AddComponent<T>() where T : Component, new()
             {
@@ -2147,11 +2150,6 @@ namespace Robust.Client.GameObjects
                 return null!;
             }
 
-            public IComponent GetComponent(uint netID)
-            {
-                return null!;
-            }
-
             public bool TryGetComponent<T>([NotNullWhen(true)] out T? component) where T : class
             {
                 component = null;
@@ -2178,21 +2176,6 @@ namespace Robust.Client.GameObjects
                 return null;
             }
 
-            public bool TryGetComponent(uint netId, [NotNullWhen(true)]  out IComponent? component)
-            {
-                component = null;
-                return false;
-            }
-
-            public IComponent? GetComponentOrNull(uint netId)
-            {
-                return null;
-            }
-
-            public void Shutdown()
-            {
-            }
-
             public void Delete()
             {
             }

Robust.Client/GameObjects/EntityManagerExt.cs

@@ -9,7 +9,7 @@ namespace Robust.Client.GameObjects
     public static class EntityManagerExt
     {
         public static void RaisePredictiveEvent<T>(this IEntityManager entityManager, T msg)
-            where T : EntitySystemMessage
+            where T : EntityEventArgs
         {
             var localPlayer = IoCManager.Resolve<IPlayerManager>().LocalPlayer;
             DebugTools.AssertNotNull(localPlayer);

Robust.Client/GameObjects/EntitySystems/AudioSystem.cs

@@ -8,7 +8,6 @@ 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.Player;
@@ -165,6 +164,12 @@ namespace Robust.Client.GameObjects
                             Logger.Warning("Interrupting positional audio, can't set position.");
                             stream.Source.StopPlaying();
                         }
+
+                        if (stream.TrackingEntity != null)
+                        {
+                            stream.Source.SetVelocity(stream.TrackingEntity.GlobalLinearVelocity());
+                        }
+
                     }
                 }
             }
@@ -188,7 +193,7 @@ namespace Robust.Client.GameObjects
         /// </summary>
         /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream? Play(string filename, AudioParams? audioParams = null)
+        private IPlayingAudioStream? Play(string filename, AudioParams? audioParams = null)
         {
             if (_resourceCache.TryGetResource<AudioResource>(new ResourcePath(filename), out var audio))
             {
@@ -204,7 +209,7 @@ namespace Robust.Client.GameObjects
         /// </summary>
         /// <param name="stream">The audio stream to play.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream Play(AudioStream stream, AudioParams? audioParams = null)
+        private IPlayingAudioStream Play(AudioStream stream, AudioParams? audioParams = null)
         {
             var source = _clyde.CreateAudioSource(stream);
             ApplyAudioParams(audioParams, source);
@@ -226,7 +231,7 @@ namespace Robust.Client.GameObjects
         /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
         /// <param name="entity">The entity "emitting" the audio.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream? Play(string filename, IEntity entity, AudioParams? audioParams = null)
+        private IPlayingAudioStream? Play(string filename, IEntity entity, AudioParams? audioParams = null)
         {
             if (_resourceCache.TryGetResource<AudioResource>(new ResourcePath(filename), out var audio))
             {
@@ -243,7 +248,7 @@ namespace Robust.Client.GameObjects
         /// <param name="stream">The audio stream to play.</param>
         /// <param name="entity">The entity "emitting" the audio.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream? Play(AudioStream stream, IEntity entity, AudioParams? audioParams = null)
+        private IPlayingAudioStream? Play(AudioStream stream, IEntity entity, AudioParams? audioParams = null)
         {
             var source = _clyde.CreateAudioSource(stream);
             if (!source.SetPosition(entity.Transform.WorldPosition))
@@ -272,7 +277,7 @@ namespace Robust.Client.GameObjects
         /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
         /// <param name="coordinates">The coordinates at which to play the audio.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream? Play(string filename, EntityCoordinates coordinates, AudioParams? audioParams = null)
+        private IPlayingAudioStream? Play(string filename, EntityCoordinates coordinates, AudioParams? audioParams = null)
         {
             if (_resourceCache.TryGetResource<AudioResource>(new ResourcePath(filename), out var audio))
             {
@@ -289,7 +294,7 @@ namespace Robust.Client.GameObjects
         /// <param name="stream">The audio stream to play.</param>
         /// <param name="coordinates">The coordinates at which to play the audio.</param>
         /// <param name="audioParams"></param>
-        public IPlayingAudioStream? Play(AudioStream stream, EntityCoordinates coordinates,
+        private IPlayingAudioStream? Play(AudioStream stream, EntityCoordinates coordinates,
             AudioParams? audioParams = null)
         {
             var source = _clyde.CreateAudioSource(stream);

Robust.Client/GameObjects/EntitySystems/ClientOccluderSystem.cs

@@ -106,7 +106,7 @@ namespace Robust.Client.GameObjects
     /// <summary>
     ///     Event raised by a <see cref="ClientOccluderComponent"/> when it needs to be recalculated.
     /// </summary>
-    internal sealed class OccluderDirtyEvent : EntitySystemMessage
+    internal sealed class OccluderDirtyEvent : EntityEventArgs
     {
         public OccluderDirtyEvent(IEntity sender, (GridId grid, Vector2i pos)? lastPosition, SnapGridOffset offset)
         {

Robust.Client/GameObjects/EntitySystems/EffectSystem.cs

@@ -11,6 +11,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
+using Robust.Shared.Enums;
 
 namespace Robust.Client.GameObjects
 {
@@ -42,7 +43,7 @@ namespace Robust.Client.GameObjects
         {
             base.Shutdown();
 
-            overlayManager.RemoveOverlay("EffectSystem");
+            overlayManager.RemoveOverlay(typeof(EffectOverlay));
         }
 
         public void CreateEffect(EffectSystemMessage message)
@@ -329,7 +330,6 @@ namespace Robust.Client.GameObjects
         {
             private readonly IPlayerManager _playerManager;
 
-            public override bool AlwaysDirty => true;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
             private readonly ShaderInstance _unshadedShader;
@@ -337,8 +337,7 @@ namespace Robust.Client.GameObjects
             private readonly IMapManager _mapManager;
             private readonly IEntityManager _entityManager;
 
-            public EffectOverlay(EffectSystem owner, IPrototypeManager protoMan, IMapManager mapMan, IPlayerManager playerMan, IEntityManager entityManager) : base(
-                "EffectSystem")
+            public EffectOverlay(EffectSystem owner, IPrototypeManager protoMan, IMapManager mapMan, IPlayerManager playerMan, IEntityManager entityManager)
             {
                 _owner = owner;
                 _unshadedShader = protoMan.Index<ShaderPrototype>("unshaded").Instance();

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -157,7 +157,7 @@ namespace Robust.Client.GameObjects
     /// <summary>
     ///     Entity system message that is raised when the player changes attached entities.
     /// </summary>
-    public class PlayerAttachSysMessage : EntitySystemMessage
+    public class PlayerAttachSysMessage : EntityEventArgs
     {
         /// <summary>
         ///     New entity the player is attached to.

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -27,7 +27,7 @@ namespace Robust.Client.GameStates
         private uint _nextInputCmdSeq = 1;
         private readonly Queue<FullInputCmdMessage> _pendingInputs = new();
 
-        private readonly Queue<(uint sequence, GameTick sourceTick, EntitySystemMessage msg, object sessionMsg)>
+        private readonly Queue<(uint sequence, GameTick sourceTick, EntityEventArgs msg, object sessionMsg)>
             _pendingSystemMessages
                 = new();
 
@@ -126,7 +126,7 @@ namespace Robust.Client.GameStates
             _nextInputCmdSeq++;
         }
 
-        public uint SystemMessageDispatched<T>(T message) where T : EntitySystemMessage
+        public uint SystemMessageDispatched<T>(T message) where T : EntityEventArgs
         {
             if (!Predicting)
             {
@@ -242,65 +242,67 @@ namespace Robust.Client.GameStates
 
             if (!Predicting) return;
 
-            using var _ = _timing.StartPastPredictionArea();
-
-
-            if (_pendingInputs.Count > 0)
+            using(var _ = _timing.StartPastPredictionArea())
             {
-                Logger.DebugS(CVars.NetPredict.Name,  "CL> Predicted:");
+                if (_pendingInputs.Count > 0)
+                {
+                    Logger.DebugS(CVars.NetPredict.Name,  "CL> Predicted:");
+                }
+
+                var pendingInputEnumerator = _pendingInputs.GetEnumerator();
+                var pendingMessagesEnumerator = _pendingSystemMessages.GetEnumerator();
+                var hasPendingInput = pendingInputEnumerator.MoveNext();
+                var hasPendingMessage = pendingMessagesEnumerator.MoveNext();
+
+                var ping = _network.ServerChannel!.Ping / 1000f + PredictLagBias; // seconds.
+                var targetTick = _timing.CurTick.Value + _processor.TargetBufferSize +
+                                 (int) Math.Ceiling(_timing.TickRate * ping) + PredictTickBias;
+
+                // Logger.DebugS("net.predict", $"Predicting from {_lastProcessedTick} to {targetTick}");
+
+                for (var t = _lastProcessedTick.Value + 1; t <= targetTick; t++)
+                {
+                    var tick = new GameTick(t);
+                    _timing.CurTick = tick;
+
+                    while (hasPendingInput && pendingInputEnumerator.Current.Tick <= tick)
+                    {
+                        var inputCmd = pendingInputEnumerator.Current;
+
+                        _inputManager.NetworkBindMap.TryGetKeyFunction(inputCmd.InputFunctionId, out var boundFunc);
+
+                        Logger.DebugS(CVars.NetPredict.Name,
+                            $"    seq={inputCmd.InputSequence}, sub={inputCmd.SubTick}, dTick={tick}, func={boundFunc.FunctionName}, " +
+                            $"state={inputCmd.State}");
+
+
+                        input.PredictInputCommand(inputCmd);
+
+                        hasPendingInput = pendingInputEnumerator.MoveNext();
+                    }
+
+                    while (hasPendingMessage && pendingMessagesEnumerator.Current.sourceTick <= tick)
+                    {
+                        var msg = pendingMessagesEnumerator.Current.msg;
+
+                        _entities.EventBus.RaiseEvent(EventSource.Local, msg);
+                        _entities.EventBus.RaiseEvent(EventSource.Local, pendingMessagesEnumerator.Current.sessionMsg);
+
+                        hasPendingMessage = pendingMessagesEnumerator.MoveNext();
+                    }
+
+                    if (t != targetTick)
+                    {
+                        // Don't run EntitySystemManager.TickUpdate if this is the target tick,
+                        // because the rest of the main loop will call into it with the target tick later,
+                        // and it won't be a past prediction.
+                        _entitySystemManager.TickUpdate((float) _timing.TickPeriod.TotalSeconds);
+                        ((IBroadcastEventBusInternal) _entities.EventBus).ProcessEventQueue();
+                    }
+                }
             }
 
-            var pendingInputEnumerator = _pendingInputs.GetEnumerator();
-            var pendingMessagesEnumerator = _pendingSystemMessages.GetEnumerator();
-            var hasPendingInput = pendingInputEnumerator.MoveNext();
-            var hasPendingMessage = pendingMessagesEnumerator.MoveNext();
-
-            var ping = _network.ServerChannel!.Ping / 1000f + PredictLagBias; // seconds.
-            var targetTick = _timing.CurTick.Value + _processor.TargetBufferSize +
-                             (int) Math.Ceiling(_timing.TickRate * ping) + PredictTickBias;
-
-            // Logger.DebugS("net.predict", $"Predicting from {_lastProcessedTick} to {targetTick}");
-
-            for (var t = _lastProcessedTick.Value + 1; t <= targetTick; t++)
-            {
-                var tick = new GameTick(t);
-                _timing.CurTick = tick;
-
-                while (hasPendingInput && pendingInputEnumerator.Current.Tick <= tick)
-                {
-                    var inputCmd = pendingInputEnumerator.Current;
-
-                    _inputManager.NetworkBindMap.TryGetKeyFunction(inputCmd.InputFunctionId, out var boundFunc);
-
-                    Logger.DebugS(CVars.NetPredict.Name,
-                        $"    seq={inputCmd.InputSequence}, sub={inputCmd.SubTick}, dTick={tick}, func={boundFunc.FunctionName}, " +
-                        $"state={inputCmd.State}");
-
-
-                    input.PredictInputCommand(inputCmd);
-
-                    hasPendingInput = pendingInputEnumerator.MoveNext();
-                }
-
-                while (hasPendingMessage && pendingMessagesEnumerator.Current.sourceTick <= tick)
-                {
-                    var msg = pendingMessagesEnumerator.Current.msg;
-
-                    _entities.EventBus.RaiseEvent(EventSource.Local, msg);
-                    _entities.EventBus.RaiseEvent(EventSource.Local, pendingMessagesEnumerator.Current.sessionMsg);
-
-                    hasPendingMessage = pendingMessagesEnumerator.MoveNext();
-                }
-
-                if (t != targetTick)
-                {
-                    // Don't run EntitySystemManager.Update if this is the target tick,
-                    // because the rest of the main loop will call into it with the target tick later,
-                    // and it won't be a past prediction.
-                    _entitySystemManager.Update((float) _timing.TickPeriod.TotalSeconds);
-                    ((IEntityEventBus) _entities.EventBus).ProcessEventQueue();
-                }
-            }
+            _entities.TickUpdate((float) _timing.TickPeriod.TotalSeconds);
         }
 
         private void ResetPredictedEntities(GameTick curTick)

Robust.Client/GameStates/IClientGameStateManager.cs

@@ -70,6 +70,6 @@ namespace Robust.Client.GameStates
         /// <param name="message">Message being dispatched.</param>
         void InputCommandDispatched(FullInputCmdMessage message);
 
-        uint SystemMessageDispatched<T>(T message) where T : EntitySystemMessage;
+        uint SystemMessageDispatched<T>(T message) where T : EntityEventArgs;
     }
 }

Robust.Client/GameStates/NetEntityOverlay.cs

@@ -1,13 +1,16 @@
 using System.Collections.Generic;
 using Robust.Client.Graphics;
+using Robust.Client.Player;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Configuration;
 using Robust.Shared.Console;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Timing;
+using Robust.Shared.Utility;
 
 namespace Robust.Client.GameStates
 {
@@ -27,13 +30,13 @@ namespace Robust.Client.GameStates
         private const int TrafficHistorySize = 64; // Size of the traffic history bar in game ticks.
 
         /// <inheritdoc />
-        public override OverlaySpace Space => OverlaySpace.ScreenSpace;
-        
+        public override OverlaySpace Space => OverlaySpace.ScreenSpace | OverlaySpace.WorldSpace;
+
         private readonly Font _font;
         private readonly int _lineHeight;
         private readonly List<NetEntity> _netEnts = new();
 
-        public NetEntityOverlay() : base(nameof(NetEntityOverlay))
+        public NetEntityOverlay()
         {
             IoCManager.InjectDependencies(this);
             var cache = IoCManager.Resolve<IResourceCache>();
@@ -42,12 +45,12 @@ namespace Robust.Client.GameStates
 
             _gameStateManager.GameStateApplied += HandleGameStateApplied;
         }
-        
+
         private void HandleGameStateApplied(GameStateAppliedArgs args)
         {
             if(_gameTiming.InPrediction) // we only care about real server states.
                 return;
-            
+
             // Shift traffic history down one
             for (var i = 0; i < _netEnts.Count; i++)
             {
@@ -74,7 +77,7 @@ namespace Robust.Client.GameStates
 
                         if (netEnt.Id != entityState.Uid)
                             continue;
-                    
+
                         //TODO: calculate size of state and record it here.
                         netEnt.Traffic[^1] = 1;
                         netEnt.LastUpdate = gameState.ToSequence;
@@ -94,15 +97,15 @@ namespace Robust.Client.GameStates
             }
 
             bool pvsEnabled = _configurationManager.GetCVar<bool>("net.pvs");
-            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*2, pvsSize*2));
+            Box2 pvsBox = Box2.CenteredAround(pvsCenter.Position, new Vector2(pvsRange*2, pvsRange*2));
 
             int timeout = _gameTiming.TickRate * 3;
             for (int i = 0; i < _netEnts.Count; i++)
             {
                 var netEnt = _netEnts[i];
-                
+
                 if(_entityManager.EntityExists(netEnt.Id))
                 {
                     //TODO: Whoever is working on PVS remake, change the InPVS detection.
@@ -123,22 +126,58 @@ namespace Robust.Client.GameStates
                 _netEnts[i] = netEnt; // copy struct back
             }
         }
-        
+
         protected override void Draw(DrawingHandleBase handle, OverlaySpace currentSpace)
         {
             if (!_netManager.IsConnected)
                 return;
 
+            switch (currentSpace)
+            {
+                case OverlaySpace.ScreenSpace:
+                    DrawScreen(handle);
+                    break;
+                case OverlaySpace.WorldSpace:
+                    DrawWorld(handle);
+                    break;
+            }
+        }
+
+        private void DrawWorld(DrawingHandleBase handle)
+        {
+            bool pvsEnabled = _configurationManager.GetCVar<bool>("net.pvs");
+
+            if(!pvsEnabled)
+                return;
+
+            float pvsSize = _configurationManager.GetCVar<float>("net.maxupdaterange");
+            var pvsCenter = _eyeManager.CurrentEye.Position;
+            Box2 pvsBox = Box2.CenteredAround(pvsCenter.Position, new Vector2(pvsSize, pvsSize));
+
+            var worldHandle = (DrawingHandleWorld)handle;
+
+            worldHandle.DrawRect(pvsBox, Color.Red, false);
+        }
+
+        private void DrawScreen(DrawingHandleBase handle)
+        {
             // remember, 0,0 is top left of ui with +X right and +Y down
-            var screenHandle = (DrawingHandleScreen)handle;
-            
+            var screenHandle = (DrawingHandleScreen) handle;
+
             for (int i = 0; i < _netEnts.Count; i++)
             {
                 var netEnt = _netEnts[i];
 
+                if (!_entityManager.TryGetEntity(netEnt.Id, out var ent))
+                {
+                    _netEnts.RemoveSwap(i);
+                    i--;
+                    continue;
+                }
+
                 var xPos = 100;
                 var yPos = 10 + _lineHeight * i;
-                var name = $"({netEnt.Id}) {_entityManager.GetEntity(netEnt.Id).Prototype?.ID}";
+                var name = $"({netEnt.Id}) {ent.Prototype?.ID}";
                 var color = CalcTextColor(ref netEnt);
                 DrawString(screenHandle, _font, new Vector2(xPos + (TrafficHistorySize + 4), yPos), name, color);
                 DrawTrafficBox(screenHandle, ref netEnt, xPos, yPos);
@@ -179,20 +218,19 @@ namespace Robust.Client.GameStates
             return Color.Green; // Entity in PVS, but not updated recently.
         }
 
-        protected override void Dispose(bool disposing)
+        protected override void DisposeBehavior()
         {
             _gameStateManager.GameStateApplied -= HandleGameStateApplied;
-
-            base.Dispose(disposing);
+            base.DisposeBehavior();
         }
 
         private static void DrawString(DrawingHandleScreen handle, Font font, Vector2 pos, string str, Color textColor)
         {
             var baseLine = new Vector2(pos.X, font.GetAscent(1) + pos.Y);
 
-            foreach (var chr in str)
+            foreach (var rune in str.EnumerateRunes())
             {
-                var advance = font.DrawChar(handle, chr, baseLine, 1, textColor);
+                var advance = font.DrawChar(handle, rune, baseLine, 1, textColor);
                 baseLine += new Vector2(advance, 0);
             }
         }
@@ -225,7 +263,7 @@ namespace Robust.Client.GameStates
             {
                 if (args.Length != 1)
                 {
-                    shell.WriteError("Invalid argument amount. Expected 2 arguments.");
+                    shell.WriteError("Invalid argument amount. Expected 1 arguments.");
                     return;
                 }
 
@@ -238,14 +276,14 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if(bValue && !overlayMan.HasOverlay(nameof(NetEntityOverlay)))
+                if(bValue && !overlayMan.HasOverlay(typeof(NetEntityOverlay)))
                 {
                     overlayMan.AddOverlay(new NetEntityOverlay());
                     shell.WriteLine("Enabled network entity report overlay.");
                 }
-                else if(!bValue && overlayMan.HasOverlay(nameof(NetEntityOverlay)))
+                else if(!bValue && overlayMan.HasOverlay(typeof(NetEntityOverlay)))
                 {
-                    overlayMan.RemoveOverlay(nameof(NetEntityOverlay));
+                    overlayMan.RemoveOverlay(typeof(NetEntityOverlay));
                     shell.WriteLine("Disabled network entity report overlay.");
                 }
             }

Robust.Client/GameStates/NetGraphOverlay.cs

@@ -1,7 +1,11 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Text;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
 using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
@@ -34,7 +38,11 @@ namespace Robust.Client.GameStates
 
         private readonly List<(GameTick Tick, int Payload, int lag, int interp)> _history = new(HistorySize+10);
 
-        public NetGraphOverlay() : base(nameof(NetGraphOverlay))
+        private int _totalHistoryPayload; // sum of all data point sizes in bytes
+
+        public EntityUid WatchEntId { get; set; }
+
+        public NetGraphOverlay()
         {
             IoCManager.InjectDependencies(this);
             var cache = IoCManager.Resolve<IResourceCache>();
@@ -58,7 +66,73 @@ namespace Robust.Client.GameStates
             // calc interp info
             var interpBuff = _gameStateManager.CurrentBufferSize - _gameStateManager.MinBufferSize;
 
+            _totalHistoryPayload += sz;
             _history.Add((toSeq, sz, lag, interpBuff));
+
+            // not watching an ent
+            if(!WatchEntId.IsValid() || WatchEntId.IsClientSide())
+                return;
+
+            string? entStateString = null;
+            string? entDelString = null;
+            var conShell = IoCManager.Resolve<IConsoleHost>().LocalShell;
+
+            var entStates = args.AppliedState.EntityStates;
+            if (entStates is not null)
+            {
+                var sb = new StringBuilder();
+                foreach (var entState in entStates)
+                {
+                    if (entState.Uid == WatchEntId)
+                    {
+                        if(entState.ComponentChanges is not null)
+                        {
+                            sb.Append($"\n  Changes:");
+                            foreach (var compChange in entState.ComponentChanges)
+                            {
+                                var del = compChange.Deleted ? 'D' : 'C';
+                                sb.Append($"\n    [{del}]{compChange.NetID}:{compChange.ComponentName}");
+                            }
+                        }
+
+                        if (entState.ComponentStates is not null)
+                        {
+                            sb.Append($"\n  States:");
+                            foreach (var compState in entState.ComponentStates)
+                            {
+                                sb.Append($"\n    {compState.NetID}:{compState.GetType().Name}");
+                            }
+                        }
+                    }
+                }
+                entStateString = sb.ToString();
+            }
+
+            var entDeletes = args.AppliedState.EntityDeletions;
+            if (entDeletes is not null)
+            {
+                var sb = new StringBuilder();
+                foreach (var entDelete in entDeletes)
+                {
+                    if (entDelete == WatchEntId)
+                    {
+                        entDelString = "\n  Deleted";
+                    }
+                }
+            }
+
+            if (!string.IsNullOrWhiteSpace(entStateString) || !string.IsNullOrWhiteSpace(entDelString))
+            {
+                var fullString = $"watchEnt: from={args.AppliedState.FromSequence}, to={args.AppliedState.ToSequence}, eid={WatchEntId}";
+                if (!string.IsNullOrWhiteSpace(entStateString))
+                    fullString += entStateString;
+
+                if (!string.IsNullOrWhiteSpace(entDelString))
+                    fullString += entDelString;
+
+                conShell.WriteLine(fullString + "\n");
+            }
+
         }
 
         /// <inheritdoc />
@@ -67,10 +141,16 @@ namespace Robust.Client.GameStates
             base.FrameUpdate(args);
 
             var over = _history.Count - HistorySize;
-            if (over > 0)
+            if (over <= 0)
+                return;
+
+            for (int i = 0; i < over; i++)
             {
-                _history.RemoveRange(0, over);
+                var point = _history[i];
+                _totalHistoryPayload -= point.Payload;
             }
+
+            _history.RemoveRange(0, over);
         }
 
         protected override void Draw(DrawingHandleBase handle, OverlaySpace currentSpace)
@@ -80,6 +160,7 @@ namespace Robust.Client.GameStates
             var leftMargin = 300;
             var width = HistorySize;
             var height = 500;
+            var drawSizeThreshold = Math.Min(_totalHistoryPayload / HistorySize, 300);
 
             // bottom payload line
             handle.DrawLine(new Vector2(leftMargin, height), new Vector2(leftMargin + width, height), Color.DarkGray.WithAlpha(0.8f));
@@ -99,6 +180,12 @@ namespace Robust.Client.GameStates
                 var yoff = height - state.Payload / BytesPerPixel;
                 handle.DrawLine(new Vector2(xOff, height), new Vector2(xOff, yoff), Color.LightGreen.WithAlpha(0.8f));
 
+                // Draw size if above average
+                if (drawSizeThreshold * 1.5 < state.Payload)
+                {
+                    DrawString((DrawingHandleScreen) handle, _font, new Vector2(xOff, yoff - _font.GetLineHeight(1)), state.Payload.ToString());
+                }
+
                 // second tick marks
                 if (state.Tick.Value % _gameTiming.TickRate == 0)
                 {
@@ -123,6 +210,10 @@ namespace Robust.Client.GameStates
                 handle.DrawLine(new Vector2(xOff, height + LowerGraphOffset), new Vector2(xOff, height + LowerGraphOffset + state.interp * 6), interpColor.WithAlpha(0.8f));
             }
 
+            // average payload line
+            var avgyoff = height - drawSizeThreshold / BytesPerPixel;
+            handle.DrawLine(new Vector2(leftMargin, avgyoff), new Vector2(leftMargin + width, avgyoff), Color.DarkGray.WithAlpha(0.8f));
+
             // top payload warning line
             var warnYoff = height - _warningPayloadSize / BytesPerPixel;
             handle.DrawLine(new Vector2(leftMargin, warnYoff), new Vector2(leftMargin + width, warnYoff), Color.DarkGray.WithAlpha(0.8f));
@@ -142,20 +233,20 @@ namespace Robust.Client.GameStates
             DrawString((DrawingHandleScreen)handle, _font, new Vector2(leftMargin, height + LowerGraphOffset), $"{_gameStateManager.CurrentBufferSize.ToString()} states");
         }
 
-        protected override void Dispose(bool disposing)
+        protected override void DisposeBehavior()
         {
             _gameStateManager.GameStateApplied -= HandleGameStateApplied;
 
-            base.Dispose(disposing);
+            base.DisposeBehavior();
         }
 
         private void DrawString(DrawingHandleScreen handle, Font font, Vector2 pos, string str)
         {
             var baseLine = new Vector2(pos.X, font.GetAscent(1) + pos.Y);
 
-            foreach (var chr in str)
+            foreach (var rune in str.EnumerateRunes())
             {
-                var advance = font.DrawChar(handle, chr, baseLine, 1, Color.White);
+                var advance = font.DrawChar(handle, rune, baseLine, 1, Color.White);
                 baseLine += new Vector2(advance, 0);
             }
         }
@@ -183,17 +274,48 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if(bValue && !overlayMan.HasOverlay(nameof(NetGraphOverlay)))
+                if(bValue && !overlayMan.HasOverlay(typeof(NetGraphOverlay)))
                 {
                     overlayMan.AddOverlay(new NetGraphOverlay());
                     shell.WriteLine("Enabled network overlay.");
                 }
-                else if(overlayMan.HasOverlay(nameof(NetGraphOverlay)))
+                else if(overlayMan.HasOverlay(typeof(NetGraphOverlay)))
                 {
-                    overlayMan.RemoveOverlay(nameof(NetGraphOverlay));
+                    overlayMan.RemoveOverlay(typeof(NetGraphOverlay));
                     shell.WriteLine("Disabled network overlay.");
                 }
             }
         }
+
+        private class NetWatchEntCommand : IConsoleCommand
+        {
+            public string Command => "net_watchent";
+            public string Help => "net_watchent <0|EntityUid>";
+            public string Description => "Dumps all network updates for an EntityId to the console.";
+
+            public void Execute(IConsoleShell shell, string argStr, string[] args)
+            {
+                if (args.Length != 1)
+                {
+                    shell.WriteError("Invalid argument amount. Expected 1 argument.");
+                    return;
+                }
+
+                if (!EntityUid.TryParse(args[0], out var eValue))
+                {
+                    shell.WriteError("Invalid argument: Needs to be 0 or an entityId.");
+                    return;
+                }
+                
+                var overlayMan = IoCManager.Resolve<IOverlayManager>();
+                
+                if (overlayMan.HasOverlay(typeof(NetGraphOverlay)))
+                {
+                    var netOverlay = overlayMan.GetOverlay<NetGraphOverlay>();
+
+                    netOverlay.WatchEntId = eValue;
+                }
+            }
+        }
     }
 }

Robust.Client/GameStates/NetInterpOverlay.cs

@@ -1,3 +1,4 @@
+using Robust.Shared.Enums;
 using Robust.Client.Graphics;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
@@ -5,6 +6,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
+using System;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.GameStates
@@ -18,7 +20,7 @@ namespace Robust.Client.GameStates
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
         private readonly ShaderInstance _shader;
 
-        public NetInterpOverlay() : base(nameof(NetInterpOverlay))
+        public NetInterpOverlay()
         {
             IoCManager.InjectDependencies(this);
             _shader = _prototypeManager.Index<ShaderPrototype>("unshaded").Instance();
@@ -85,14 +87,14 @@ namespace Robust.Client.GameStates
                 var bValue = iValue > 0;
                 var overlayMan = IoCManager.Resolve<IOverlayManager>();
 
-                if (bValue && !overlayMan.HasOverlay(nameof(NetInterpOverlay)))
+                if (bValue && !overlayMan.HasOverlay<NetInterpOverlay>())
                 {
                     overlayMan.AddOverlay(new NetInterpOverlay());
                     shell.WriteLine("Enabled network interp overlay.");
                 }
-                else if (overlayMan.HasOverlay(nameof(NetInterpOverlay)))
+                else if (overlayMan.HasOverlay<NetInterpOverlay>())
                 {
-                    overlayMan.RemoveOverlay(nameof(NetInterpOverlay));
+                    overlayMan.RemoveOverlay<NetInterpOverlay>();
                     shell.WriteLine("Disabled network interp overlay.");
                 }
             }

Robust.Client/Graphics/AtlasTexture.cs

@@ -1,4 +1,4 @@
-using JetBrains.Annotations;
+using JetBrains.Annotations;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 

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

@@ -53,7 +53,7 @@ namespace Robust.Client.Graphics.Clyde
 
             IsEfxSupported = HasAlDeviceExtension("ALC_EXT_EFX");
 
-            _configurationManager.OnValueChanged(CVars.AudioMasterVolume, SetMasterVolume, true);
+            ConfigurationManager.OnValueChanged(CVars.AudioMasterVolume, SetMasterVolume, true);
         }
 
         private void _audioCreateContext()
@@ -81,7 +81,7 @@ namespace Robust.Client.Graphics.Clyde
 
         private void _audioOpenDevice()
         {
-            var preferredDevice = _configurationManager.GetCVar(CVars.AudioDevice);
+            var preferredDevice = ConfigurationManager.GetCVar(CVars.AudioDevice);
 
             // Open device.
             if (!string.IsNullOrEmpty(preferredDevice))
@@ -482,7 +482,7 @@ namespace Robust.Client.Graphics.Clyde
 
                 var (x, y) = position;
 
-                if (!ValidatePosition(x, y))
+                if (!AreFinite(x, y))
                 {
                     return false;
                 }
@@ -503,7 +503,7 @@ namespace Robust.Client.Graphics.Clyde
                 return true;
             }
 
-            private static bool ValidatePosition(float x, float y)
+            private static bool AreFinite(float x, float y)
             {
                 if (float.IsFinite(x) && float.IsFinite(y))
                 {
@@ -513,6 +513,22 @@ namespace Robust.Client.Graphics.Clyde
                 return false;
             }
 
+            public void SetVelocity(Vector2 velocity)
+            {
+                _checkDisposed();
+
+                var (x, y) = velocity;
+
+                if (!AreFinite(x, y))
+                {
+                    return;
+                }
+
+                AL.Source(SourceHandle, ALSource3f.Velocity, x, y, 0);
+
+                _checkAlError();
+            }
+
             public void SetPitch(float pitch)
             {
                 _checkDisposed();
@@ -667,7 +683,6 @@ namespace Robust.Client.Graphics.Clyde
                 _checkAlError();
             }
 
-
             private void SetOcclusionEfx(float gain, float cutoff)
             {
                 if (FilterHandle == 0)
@@ -694,7 +709,7 @@ namespace Robust.Client.Graphics.Clyde
 
                 var (x, y) = position;
 
-                if (!ValidatePosition(x, y))
+                if (!AreFinite(x, y))
                 {
                     return false;
                 }
@@ -706,7 +721,7 @@ namespace Robust.Client.Graphics.Clyde
                 return true;
             }
 
-            private static bool ValidatePosition(float x, float y)
+            private static bool AreFinite(float x, float y)
             {
                 if (float.IsFinite(x) && float.IsFinite(y))
                 {
@@ -716,6 +731,22 @@ namespace Robust.Client.Graphics.Clyde
                 return false;
             }
 
+            public void SetVelocity(Vector2 velocity)
+            {
+                _checkDisposed();
+
+                var (x, y) = velocity;
+
+                if (!AreFinite(x, y))
+                {
+                    return;
+                }
+
+                AL.Source(SourceHandle!.Value, ALSource3f.Velocity, x, y, 0);
+
+                _checkAlError();
+            }
+
             public void SetPitch(float pitch)
             {
                 _checkDisposed();

Robust.Client/Graphics/Clyde/Clyde.DllMap.cs

@@ -12,7 +12,8 @@ namespace Robust.Client.Graphics.Clyde
         static Clyde()
         {
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows) &&
-                RuntimeInformation.ProcessArchitecture == Architecture.X64)
+                RuntimeInformation.ProcessArchitecture == Architecture.X64 &&
+                Environment.GetEnvironmentVariable("ROBUST_INTEGRATED_GPU") != "1")
             {
                 try
                 {

Robust.Client/Graphics/Clyde/Clyde.GLFeatures.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using OpenToolkit.Graphics.OpenGL4;
 using Robust.Shared.Log;
@@ -115,7 +115,7 @@ namespace Robust.Client.Graphics.Clyde
 
                 var prev = cap;
                 var cVarName = $"display.ogl_block_{capName}";
-                var block = _configurationManager.GetCVar<bool>(cVarName);
+                var block = ConfigurationManager.GetCVar<bool>(cVarName);
 
                 if (block)
                 {
@@ -146,7 +146,7 @@ namespace Robust.Client.Graphics.Clyde
 
             foreach (var cvar in cvars)
             {
-                _configurationManager.RegisterCVar($"display.ogl_block_{cvar}", false);
+                ConfigurationManager.RegisterCVar($"display.ogl_block_{cvar}", false);
             }
         }
 

Robust.Client/Graphics/Clyde/Clyde.HLR.cs

@@ -7,6 +7,8 @@ using Robust.Client.ResourceManagement;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
+using OpenToolkit.Graphics.OpenGL4;
+using Robust.Shared.Enums;
 
 namespace Robust.Client.Graphics.Clyde
 {
@@ -68,8 +70,7 @@ namespace Robust.Client.Graphics.Clyde
             RenderOverlays(OverlaySpace.ScreenSpaceBelowWorld);
 
             _mainViewport.Eye = _eyeManager.CurrentEye;
-            RenderViewport(_mainViewport);
-
+            RenderViewport(_mainViewport); //Worldspace overlays are rendered here.
             {
                 var handle = _renderHandle.DrawingHandleScreen;
                 var tex = _mainViewport.RenderTarget.Texture;
@@ -107,25 +108,67 @@ namespace Robust.Client.Graphics.Clyde
                         list.Add(overlay);
                     }
                 }
-
-                list.Sort(OverlayComparer.Instance);
-
-                foreach (var overlay in list)
-                {
-                    overlay.ClydeRender(_renderHandle, space);
-                }
-
                 FlushRenderQueue();
+                list.Sort(OverlayComparer.Instance);
+                foreach (var overlay in list) {
+                    if (overlay.RequestScreenTexture) {
+                        FlushRenderQueue();
+                        UpdateOverlayScreenTexture(space, _mainViewport.RenderTarget);
+                    }
+                    if (overlay.OverwriteTargetFrameBuffer()) {
+                        ClearFramebuffer(default);
+                    }
+                    overlay.ClydeRender(_renderHandle, space);
+                    FlushRenderQueue();
+                }
             }
         }
 
-        private void DrawEntitiesAndWorldOverlay(Viewport viewport, Box2 worldBounds)
+        private ClydeTexture? ScreenBufferTexture;
+        private GLHandle screenBufferHandle;
+        private Vector2 lastFrameSize;
+        /// <summary>
+        ///    Sends SCREEN_TEXTURE to all overlays in the given OverlaySpace that request it.
+        /// </summary>
+        private bool UpdateOverlayScreenTexture(OverlaySpace space, RenderTexture texture) {
+            //This currently does NOT consider viewports and just grabs the current screen framebuffer. This will need to be improved upon in the future.
+            List<Overlay> oTargets = new List<Overlay>();
+            foreach (var overlay in _overlayManager.AllOverlays) {
+                if (overlay.RequestScreenTexture && overlay.Space == space) {
+                    oTargets.Add(overlay);
+                }
+            }
+            if (oTargets.Count > 0 && ScreenBufferTexture != null) {
+                if (lastFrameSize != _framebufferSize) {
+                    GL.BindTexture(TextureTarget.Texture2D, screenBufferHandle.Handle);
+                    GL.TexImage2D(TextureTarget.Texture2D, 0, _hasGLSrgb ? PixelInternalFormat.Srgb8Alpha8 : PixelInternalFormat.Rgba8, _framebufferSize.X, _framebufferSize.Y, 0,
+                        PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero);
+                }
+                lastFrameSize = _framebufferSize;
+                CopyRenderTextureToTexture(texture, ScreenBufferTexture);
+                foreach (Overlay overlay in oTargets) {
+                    overlay.ScreenTexture = ScreenBufferTexture;
+                }
+                oTargets.Clear();
+                return true;
+            }
+            return false;
+        }
+
+
+
+
+
+
+        private void DrawEntities(Viewport viewport, Box2 worldBounds)
         {
             if (_eyeManager.CurrentMap == MapId.Nullspace || !_mapManager.HasMapEntity(_eyeManager.CurrentMap))
             {
                 return;
             }
 
+            RenderOverlays(OverlaySpace.WorldSpaceBelowEntities);
+
             var screenSize = viewport.Size;
 
             // So we could calculate the correct size of the entities based on the contents of their sprite...
@@ -267,14 +310,6 @@ namespace Robust.Client.Graphics.Clyde
 
             _drawingSpriteList.Clear();
             FlushRenderQueue();
-
-            // Cleanup remainders
-            foreach (var overlay in worldOverlays)
-            {
-                overlay.ClydeRender(_renderHandle, OverlaySpace.WorldSpace);
-            }
-
-            FlushRenderQueue();
         }
 
         [MethodImpl(MethodImplOptions.NoInlining)]
@@ -368,12 +403,21 @@ namespace Robust.Client.Graphics.Clyde
                     // We will also render worldspace overlays here so we can do them under / above entities as necessary
                     using (DebugGroup("Entities"))
                     {
-                        DrawEntitiesAndWorldOverlay(viewport, worldBounds);
+                        DrawEntities(viewport, worldBounds);
                     }
 
+                    RenderOverlays(OverlaySpace.WorldSpaceBelowFOV);
+
                     if (_lightManager.Enabled && _lightManager.DrawHardFov && eye.DrawFov)
                     {
+                        GL.Clear(ClearBufferMask.StencilBufferBit);
+                        GL.Enable(EnableCap.StencilTest);
+                        GL.StencilOp(OpenToolkit.Graphics.OpenGL4.StencilOp.Keep, OpenToolkit.Graphics.OpenGL4.StencilOp.Keep, OpenToolkit.Graphics.OpenGL4.StencilOp.Replace);
+                        GL.StencilFunc(StencilFunction.Always, 1, 0xFF);
+                        GL.StencilMask(0xFF);
                         ApplyFovToBuffer(viewport, eye);
+                        GL.StencilMask(0x00);
+                        GL.Disable(EnableCap.StencilTest);
                     }
                 }
 
@@ -401,6 +445,14 @@ namespace Robust.Client.Graphics.Clyde
                         viewport.WallBleedIntermediateRenderTarget2.Texture,
                         UIBox2.FromDimensions(Vector2.Zero, ScreenSize), new Color(1, 1, 1, 0.5f));
                 }
+
+
+                RenderOverlays(OverlaySpace.WorldSpace);
+
+                GL.StencilFunc(StencilFunction.Notequal, 1, 0xFF);
+                GL.Disable(EnableCap.DepthTest);
+                RenderOverlays(OverlaySpace.WorldSpaceFOVStencil);
+                GL.Disable(EnableCap.StencilTest);
             }
 
             PopRenderStateFull(state);

Robust.Client/Graphics/Clyde/Clyde.Helpers.cs

@@ -5,6 +5,7 @@ using OpenToolkit.Graphics.OpenGL4;
 using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
+using SixLabors.ImageSharp.PixelFormats;
 using ES20 = OpenToolkit.Graphics.ES20;
 
 namespace Robust.Client.Graphics.Clyde
@@ -31,6 +32,27 @@ namespace Robust.Client.Graphics.Clyde
             CheckGlError();
             GL.BindTexture(TextureTarget.Texture2D, glHandle.Handle);
             CheckGlError();
+            GL.ActiveTexture(TextureUnit.Texture0);
+        }
+
+        private void CopyRenderTextureToTexture(RenderTexture source, ClydeTexture target) {
+            LoadedRenderTarget sourceLoaded = RtToLoaded(source);
+            bool pause = sourceLoaded != _currentBoundRenderTarget;
+            FullStoredRendererState? store = null;
+            if (pause) {
+                store = PushRenderStateFull();
+                BindRenderTargetFull(source);
+                CheckGlError();
+            }
+
+            GL.BindTexture(TextureTarget.Texture2D, _loadedTextures[target.TextureId].OpenGLObject.Handle);
+            CheckGlError();
+            GL.CopyTexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, 0, 0, _framebufferSize.X, _framebufferSize.Y);
+            CheckGlError();
+
+            if (pause && store != null) {
+                PopRenderStateFull((FullStoredRendererState)store);
+            }
         }
 
         private static long EstPixelSize(PixelInternalFormat format)

Robust.Client/Graphics/Clyde/Clyde.LightRendering.cs

@@ -10,6 +10,7 @@ using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using static Robust.Client.GameObjects.ClientOccluderComponent;
 using OGLTextureWrapMode = OpenToolkit.Graphics.OpenGL.TextureWrapMode;
+using TKStencilOp = OpenToolkit.Graphics.OpenGL4.StencilOp;
 
 namespace Robust.Client.Graphics.Clyde
 {
@@ -195,7 +196,6 @@ namespace Robust.Client.Graphics.Clyde
                 }
             }
 
-
             _lightSoftShaderHandle = LoadShaderHandle("/Shaders/Internal/light-soft.swsl");
             _lightHardShaderHandle = LoadShaderHandle("/Shaders/Internal/light-hard.swsl");
             _fovShaderHandle = LoadShaderHandle("/Shaders/Internal/fov.swsl");
@@ -361,16 +361,23 @@ namespace Robust.Client.Graphics.Clyde
                 FinalizeDepthDraw();
             }
 
-            BindRenderTargetImmediate(RtToLoaded(viewport.LightRenderTarget));
-            CheckGlError();
-            GLClearColor(_lightManager.AmbientLightColor);
-            GL.Clear(ClearBufferMask.ColorBufferBit);
-            CheckGlError();
+            GL.Enable(EnableCap.StencilTest);
+            _isStencilling = true;
 
             var (lightW, lightH) = GetLightMapSize(viewport.Size);
             GL.Viewport(0, 0, lightW, lightH);
             CheckGlError();
 
+            BindRenderTargetImmediate(RtToLoaded(viewport.LightRenderTarget));
+            CheckGlError();
+            GLClearColor(_lightManager.AmbientLightColor);
+            GL.ClearStencil(0xFF);
+            GL.StencilMask(0xFF);
+            GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.StencilBufferBit);
+            CheckGlError();
+
+            ApplyLightingFovToBuffer(viewport, eye);
+
             var lightShader = _loadedShaders[_enableSoftShadows ? _lightSoftShaderHandle : _lightHardShaderHandle].Program;
             lightShader.Use();
 
@@ -382,6 +389,11 @@ namespace Robust.Client.Graphics.Clyde
             GL.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.One);
             CheckGlError();
 
+            GL.StencilFunc(StencilFunction.Equal, 0xFF, 0xFF);
+            CheckGlError();
+            GL.StencilOp(TKStencilOp.Keep, TKStencilOp.Keep, TKStencilOp.Keep);
+            CheckGlError();
+
             var lastRange = float.NaN;
             var lastPower = float.NaN;
             var lastColor = new Color(float.NaN, float.NaN, float.NaN, float.NaN);
@@ -463,11 +475,11 @@ namespace Robust.Client.Graphics.Clyde
             }
 
             ResetBlendFunc();
+            GL.Disable(EnableCap.StencilTest);
+            _isStencilling = false;
 
             CheckGlError();
 
-            ApplyLightingFovToBuffer(viewport, eye);
-
             BlurOntoWalls(viewport, eye);
 
             MergeWallLayer(viewport);
@@ -690,6 +702,13 @@ namespace Robust.Client.Graphics.Clyde
             fovShader.SetUniformTextureMaybe(UniIMainTexture, TextureUnit.Texture0);
             fovShader.SetUniformMaybe("center", eye.Position.Position);
 
+            GL.StencilMask(0xFF);
+            CheckGlError();
+            GL.StencilFunc(StencilFunction.Always, 0, 0);
+            CheckGlError();
+            GL.StencilOp(TKStencilOp.Keep, TKStencilOp.Keep, TKStencilOp.Replace);
+            CheckGlError();
+
             DrawBlit(viewport, fovShader);
 
             if (_hasGLSamplerObjects)
@@ -939,7 +958,8 @@ namespace Robust.Client.Graphics.Clyde
             viewport.WallMaskRenderTarget = CreateRenderTarget(viewport.Size, RenderTargetColorFormat.R8,
                 name: $"{viewport.Name}-{nameof(viewport.WallMaskRenderTarget)}");
 
-            viewport.LightRenderTarget = CreateRenderTarget(lightMapSize, lightMapColorFormat,
+            viewport.LightRenderTarget = CreateRenderTarget(lightMapSize,
+                new RenderTargetFormatParameters(lightMapColorFormat, hasDepthStencil: true),
                 lightMapSampleParameters,
                 $"{viewport.Name}-{nameof(viewport.LightRenderTarget)}");
 

Robust.Client/Graphics/Clyde/Clyde.RenderTargets.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;

Robust.Client/Graphics/Clyde/Clyde.Rendering.cs

@@ -280,7 +280,7 @@ namespace Robust.Client.Graphics.Clyde
         }
 
         /// <summary>
-        ///     Flush the render handle, processing and re-pooling all the command lists.
+        ///     Flushes the render handle, processing and re-pooling all the command lists.
         /// </summary>
         private void FlushRenderQueue()
         {
@@ -371,6 +371,7 @@ namespace Robust.Client.Graphics.Clyde
 
             program.Use();
 
+            int textureUnitVal = 0;
             // Assign shader parameters to uniform since they may be dirty.
             foreach (var (name, value) in instance.Parameters)
             {
@@ -413,6 +414,15 @@ namespace Robust.Client.Graphics.Clyde
                     case Matrix4 matrix4:
                         program.SetUniform(name, matrix4);
                         break;
+                    case ClydeTexture clydeTexture:
+                        //It's important to start at Texture6 here since DrawCommandBatch uses Texture0 and Texture1 immediately after calling this
+                        //function! If passing in textures as uniforms ever stops working it might be since someone made it use all the way up to Texture6 too.
+                        //Might change this in the future?
+                        TextureUnit cTarget = TextureUnit.Texture6+textureUnitVal;
+                        SetTexture(cTarget, ((ClydeTexture)clydeTexture).TextureId);
+                        program.SetUniformTexture(name, cTarget);
+                        textureUnitVal++;
+                        break;
                     default:
                         throw new InvalidOperationException($"Unable to handle shader parameter {name}: {value}");
                 }

Robust.Client/Graphics/Clyde/Clyde.Shaders.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
@@ -428,7 +428,8 @@ namespace Robust.Client.Graphics.Clyde
 
             private protected override void SetParameterImpl(string name, Texture value)
             {
-                throw new NotImplementedException();
+                var data = Parent._shaderInstances[Handle];
+                data.Parameters[name] = value;
             }
 
             private protected override void SetStencilOpImpl(StencilOp op)

Robust.Client/Graphics/Clyde/Clyde.Textures.cs

@@ -26,7 +26,7 @@ namespace Robust.Client.Graphics.Clyde
 
         private readonly ConcurrentQueue<ClydeHandle> _textureDisposeQueue = new();
 
-        public Texture LoadTextureFromPNGStream(Stream stream, string? name = null,
+        public OwnedTexture LoadTextureFromPNGStream(Stream stream, string? name = null,
             TextureLoadParameters? loadParams = null)
         {
             DebugTools.Assert(_mainThread == Thread.CurrentThread);
@@ -37,7 +37,7 @@ namespace Robust.Client.Graphics.Clyde
             return LoadTextureFromImage(image, name, loadParams);
         }
 
-        public Texture LoadTextureFromImage<T>(Image<T> image, string? name = null,
+        public OwnedTexture LoadTextureFromImage<T>(Image<T> image, string? name = null,
             TextureLoadParameters? loadParams = null) where T : unmanaged, IPixel<T>
         {
             DebugTools.Assert(_mainThread == Thread.CurrentThread);
@@ -56,19 +56,19 @@ namespace Robust.Client.Graphics.Clyde
                 {
                     // Disable sRGB so stuff doesn't get interpreter wrong.
                     actualParams.Srgb = false;
-                    var img = ApplyA8Swizzle((Image<A8>) (object) image);
+                    using var img = ApplyA8Swizzle((Image<A8>) (object) image);
                     return LoadTextureFromImage(img, name, loadParams);
                 }
 
                 if (pixelType == typeof(L8) && !actualParams.Srgb)
                 {
-                    var img = ApplyL8Swizzle((Image<L8>) (object) image);
+                    using var img = ApplyL8Swizzle((Image<L8>) (object) image);
                     return LoadTextureFromImage(img, name, loadParams);
                 }
             }
 
             // Flip image because OpenGL reads images upside down.
-            var copy = FlipClone(image);
+            using var copy = FlipClone(image);
 
             var texture = CreateBaseTextureInternal<T>(image.Width, image.Height, actualParams, name);
 
@@ -324,11 +324,13 @@ namespace Robust.Client.Graphics.Clyde
                 if (typeof(T) == typeof(A8))
                 {
                     SetSubImage(texture, dstTl, ApplyA8Swizzle((Image<A8>) (object) srcImage), srcBox);
+                    return;
                 }
 
                 if (typeof(T) == typeof(L8))
                 {
                     SetSubImage(texture, dstTl, ApplyL8Swizzle((Image<L8>) (object) srcImage), srcBox);
+                    return;
                 }
             }
 

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

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Runtime.CompilerServices;
@@ -7,6 +7,7 @@ using System.Runtime.InteropServices;
 using System.Threading;
 using OpenToolkit;
 using OpenToolkit.Graphics.OpenGL4;
+using OpenToolkit.GraphicsLibraryFramework;
 using Robust.Client.Input;
 using Robust.Client.UserInterface;
 using Robust.Client.Utility;
@@ -14,6 +15,7 @@ using Robust.Shared;
 using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Maths;
+using Robust.Shared.Utility;
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 using static Robust.Client.Utility.LiterallyJustMessageBox;
@@ -46,6 +48,7 @@ namespace Robust.Client.Graphics.Clyde
     {
         // Keep delegates around to prevent GC issues.
         private GLFWCallbacks.ErrorCallback _errorCallback = default!;
+        private GLFWCallbacks.MonitorCallback _monitorCallback = default!;
         private GLFWCallbacks.CharCallback _charCallback = default!;
         private GLFWCallbacks.CursorPosCallback _cursorPosCallback = default!;
         private GLFWCallbacks.KeyCallback _keyCallback = default!;
@@ -73,6 +76,18 @@ namespace Robust.Client.Graphics.Clyde
 
         private Vector2 _lastMousePos;
 
+        // Can't use ClydeHandle because it's 64 bit.
+        private int _nextWindowId = 1;
+        private readonly Dictionary<int, MonitorReg> _monitors = new();
+
+        public event Action<TextEventArgs>? TextEntered;
+        public event Action<MouseMoveEventArgs>? MouseMove;
+        public event Action<KeyEventArgs>? KeyUp;
+        public event Action<KeyEventArgs>? KeyDown;
+        public event Action<MouseWheelEventArgs>? MouseWheel;
+        public event Action<string>? CloseWindow;
+        public event Action? OnWindowScaleChanged;
+
         // NOTE: in engine we pretend the framebuffer size is the screen size..
         // For practical reasons like UI rendering.
         public override Vector2i ScreenSize => _framebufferSize;
@@ -148,24 +163,71 @@ namespace Robust.Client.Graphics.Clyde
                 return false;
             }
 
+            InitMonitors();
             InitCursors();
 
             return InitWindow();
         }
 
+        private void InitMonitors()
+        {
+            var monitors = GLFW.GetMonitorsRaw(out var count);
+
+            for (var i = 0; i < count; i++)
+            {
+                SetupMonitor(monitors[i]);
+            }
+        }
+
+        private void SetupMonitor(Monitor* monitor)
+        {
+            var handle = _nextWindowId++;
+
+            DebugTools.Assert(GLFW.GetMonitorUserPointer(monitor) == null, "GLFW window already has user pointer??");
+
+            var name = GLFW.GetMonitorName(monitor);
+            var videoMode = GLFW.GetVideoMode(monitor);
+            var impl = new ClydeMonitorImpl(handle, name, (videoMode->Width, videoMode->Height), videoMode->RefreshRate);
+
+            GLFW.SetMonitorUserPointer(monitor, (void*) handle);
+            _monitors[handle] = new MonitorReg
+            {
+                Id = handle,
+                Impl = impl,
+                Monitor = monitor
+            };
+        }
+
+        private void DestroyMonitor(Monitor* monitor)
+        {
+            var ptr = GLFW.GetMonitorUserPointer(monitor);
+
+            if (ptr == null)
+            {
+                var name = GLFW.GetMonitorName(monitor);
+                Logger.WarningS("clyde.win", $"Monitor '{name}' had no user pointer set??");
+                return;
+            }
+
+            _monitors.Remove((int) ptr);
+            GLFW.SetMonitorUserPointer(monitor, null);
+        }
+
         private bool InitWindow()
         {
-            var width = _configurationManager.GetCVar(CVars.DisplayWidth);
-            var height = _configurationManager.GetCVar(CVars.DisplayHeight);
+            var width = ConfigurationManager.GetCVar(CVars.DisplayWidth);
+            var height = ConfigurationManager.GetCVar(CVars.DisplayHeight);
 
             Monitor* monitor = null;
 
             if (WindowMode == WindowMode.Fullscreen)
             {
-                monitor = GLFW.GetPrimaryMonitor();
+                monitor = GLFW.GetMonitors()[1];
                 var mode = GLFW.GetVideoMode(monitor);
                 width = mode->Width;
                 height = mode->Height;
+
+                GLFW.WindowHint(WindowHintInt.RefreshRate, mode->RefreshRate);
             }
 
 #if DEBUG
@@ -174,13 +236,16 @@ namespace Robust.Client.Graphics.Clyde
             GLFW.WindowHint(WindowHintString.X11ClassName, "SS14");
             GLFW.WindowHint(WindowHintString.X11InstanceName, "SS14");
 
-            var renderer = (Renderer) _configurationManager.GetCVar<int>(CVars.DisplayRenderer);
+            var renderer = (Renderer) ConfigurationManager.GetCVar<int>(CVars.DisplayRenderer);
 
-            Span<Renderer> renderers = (renderer == Renderer.Default) ? stackalloc Renderer[] {
-                Renderer.OpenGL33,
-                Renderer.OpenGL31,
-                Renderer.OpenGLES2
-            } : stackalloc Renderer[] {renderer};
+            Span<Renderer> renderers = (renderer == Renderer.Default)
+                ? stackalloc Renderer[]
+                {
+                    Renderer.OpenGL33,
+                    Renderer.OpenGL31,
+                    Renderer.OpenGLES2
+                }
+                : stackalloc Renderer[] {renderer};
 
             foreach (Renderer r in renderers)
             {
@@ -193,6 +258,7 @@ namespace Robust.Client.Graphics.Clyde
                     _isCore = renderer == Renderer.OpenGL33;
                     break;
                 }
+
                 // Window failed to init due to error.
                 // Try not to treat the error code seriously.
                 var code = GLFW.GetError(out string desc);
@@ -206,9 +272,9 @@ namespace Robust.Client.Graphics.Clyde
                     var code = GLFW.GetError(out string desc);
 
                     var errorContent = "Failed to create the game window. " +
-                        "This probably means your GPU is too old to play the game. " +
-                        "That or update your graphic drivers\n" +
-                        $"The exact error is: [{code}]\n {desc}";
+                                       "This probably means your GPU is too old to play the game. " +
+                                       "That or update your graphic drivers\n" +
+                                       $"The exact error is: [{code}]\n {desc}";
 
                     MessageBoxW(null,
                         errorContent,
@@ -301,6 +367,7 @@ namespace Robust.Client.Graphics.Clyde
                     GLFW.WindowHint(WindowHintOpenGlProfile.OpenGlProfile, OpenGlProfile.Any);
                     GLFW.WindowHint(WindowHintBool.SrgbCapable, false);
                 }
+
                 _glfwWindow = GLFW.CreateWindow(width, height, string.Empty, monitor, null);
             }
         }
@@ -393,11 +460,30 @@ namespace Robust.Client.Graphics.Clyde
             Logger.ErrorS("clyde.win.glfw", "GLFW Error: [{0}] {1}", code, description);
         }
 
+        private void OnGlfwMonitor(Monitor* monitor, ConnectedState state)
+        {
+            try
+            {
+                if (state == ConnectedState.Connected)
+                {
+                    SetupMonitor(monitor);
+                }
+                else
+                {
+                    DestroyMonitor(monitor);
+                }
+            }
+            catch (Exception e)
+            {
+                CatchCallbackException(e);
+            }
+        }
+
         private void OnGlfwChar(Window* window, uint codepoint)
         {
             try
             {
-                _gameController.TextEntered(new TextEventArgs(codepoint));
+                TextEntered?.Invoke(new TextEventArgs(codepoint));
             }
             catch (Exception e)
             {
@@ -413,8 +499,7 @@ namespace Robust.Client.Graphics.Clyde
                 var delta = newPos - _lastMousePos;
                 _lastMousePos = newPos;
 
-                var ev = new MouseMoveEventArgs(delta, newPos);
-                _gameController.MouseMove(ev);
+                MouseMove?.Invoke(new MouseMoveEventArgs(delta, newPos));
             }
             catch (Exception e)
             {
@@ -461,11 +546,11 @@ namespace Robust.Client.Graphics.Clyde
             switch (action)
             {
                 case InputAction.Release:
-                    _gameController.KeyUp(ev);
+                    KeyUp?.Invoke(ev);
                     break;
                 case InputAction.Press:
                 case InputAction.Repeat:
-                    _gameController.KeyDown(ev);
+                    KeyDown?.Invoke(ev);
                     break;
                 default:
                     throw new ArgumentOutOfRangeException(nameof(action), action, null);
@@ -477,7 +562,7 @@ namespace Robust.Client.Graphics.Clyde
             try
             {
                 var ev = new MouseWheelEventArgs(((float) offsetX, (float) offsetY), _lastMousePos);
-                _gameController.MouseWheel(ev);
+                MouseWheel?.Invoke(ev);
             }
             catch (Exception e)
             {
@@ -489,7 +574,7 @@ namespace Robust.Client.Graphics.Clyde
         {
             try
             {
-                _gameController.Shutdown("Window closed");
+                CloseWindow?.Invoke("Window closed");
             }
             catch (Exception e)
             {
@@ -533,6 +618,7 @@ namespace Robust.Client.Graphics.Clyde
             try
             {
                 _windowScale = (xScale, yScale);
+                OnWindowScaleChanged?.Invoke();
             }
             catch (Exception e)
             {
@@ -568,6 +654,7 @@ namespace Robust.Client.Graphics.Clyde
         private void StoreCallbacks()
         {
             _errorCallback = OnGlfwError;
+            _monitorCallback = OnGlfwMonitor;
             _charCallback = OnGlfwChar;
             _cursorPosCallback = OnGlfwCursorPos;
             _keyCallback = OnGlfwKey;
@@ -590,6 +677,19 @@ namespace Robust.Client.Graphics.Clyde
             GLFW.SetWindowTitle(_glfwWindow, title);
         }
 
+        public void SetWindowMonitor(IClydeMonitor monitor)
+        {
+            var monitorImpl = (ClydeMonitorImpl) monitor;
+            var reg = _monitors[monitorImpl.Id];
+
+            GLFW.SetWindowMonitor(
+                _glfwWindow,
+                reg.Monitor,
+                0, 0,
+                monitorImpl.Size.X, monitorImpl.Size.Y,
+                monitorImpl.RefreshRate);
+        }
+
         public void RequestWindowAttention()
         {
             GLFW.RequestWindowAttention(_glfwWindow);
@@ -654,18 +754,40 @@ namespace Robust.Client.Graphics.Clyde
 
                 GLFW.GetWindowPos(_glfwWindow, out var x, out var y);
                 _prevWindowPos = (x, y);
-                var monitor = GLFW.GetPrimaryMonitor();
+                var monitor = MonitorForWindow(_glfwWindow);
                 var mode = GLFW.GetVideoMode(monitor);
 
-                GLFW.SetWindowMonitor(_glfwWindow, GLFW.GetPrimaryMonitor(), 0, 0, mode->Width, mode->Height,
+                GLFW.SetWindowMonitor(_glfwWindow, monitor, 0, 0, mode->Width, mode->Height,
                     mode->RefreshRate);
             }
             else
             {
-                GLFW.SetWindowMonitor(_glfwWindow, null, _prevWindowPos.X, _prevWindowPos.Y, _prevWindowSize.X, _prevWindowSize.Y, 0);
+                GLFW.SetWindowMonitor(_glfwWindow, null, _prevWindowPos.X, _prevWindowPos.Y, _prevWindowSize.X,
+                    _prevWindowSize.Y, 0);
             }
         }
 
+        // glfwGetWindowMonitor only works for fullscreen windows.
+        // Picks the monitor with the top-left corner of the window.
+        private Monitor* MonitorForWindow(Window* window)
+        {
+            GLFW.GetWindowPos(window, out var winPosX, out var winPosY);
+            var monitors = GLFW.GetMonitorsRaw(out var count);
+            for (var i = 0; i < count; i++)
+            {
+                var monitor = monitors[i];
+                GLFW.GetMonitorPos(monitor, out var monPosX, out var monPosY);
+                var videoMode = GLFW.GetVideoMode(monitor);
+
+                var box = Box2i.FromDimensions(monPosX, monPosY, videoMode->Width, videoMode->Height);
+                if (box.Contains(winPosX, winPosY))
+                    return monitor;
+            }
+
+            // Fallback
+            return GLFW.GetPrimaryMonitor();
+        }
+
         string IClipboardManager.GetText()
         {
             return GLFW.GetClipboardString(_glfwWindow);
@@ -676,6 +798,11 @@ namespace Robust.Client.Graphics.Clyde
             GLFW.SetClipboardString(_glfwWindow, text);
         }
 
+        public IEnumerable<IClydeMonitor> EnumerateMonitors()
+        {
+            return _monitors.Values.Select(c => c.Impl);
+        }
+
         // We can't let exceptions unwind into GLFW, as that can cause the CLR to crash.
         // And it probably messes up GLFW too.
         // So all the callbacks are passed to this method.
@@ -689,5 +816,28 @@ namespace Robust.Client.Graphics.Clyde
 
             _glfwExceptionList.Add(e);
         }
+
+        private sealed class MonitorReg
+        {
+            public int Id;
+            public Monitor* Monitor;
+            public ClydeMonitorImpl Impl = default!;
+        }
+
+        private sealed class ClydeMonitorImpl : IClydeMonitor
+        {
+            public ClydeMonitorImpl(int id, string name, Vector2i size, int refreshRate)
+            {
+                Id = id;
+                Name = name;
+                Size = size;
+                RefreshRate = refreshRate;
+            }
+
+            public int Id { get; }
+            public string Name { get; }
+            public Vector2i Size { get; }
+            public int RefreshRate { get; }
+        }
     }
 }

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -87,7 +87,7 @@ namespace Robust.Client.Graphics.Clyde
         {
             base.Initialize();
 
-            _configurationManager.OnValueChanged(CVars.DisplayOGLCheckErrors, b => _checkGLErrors = b, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplayOGLCheckErrors, b => _checkGLErrors = b, true);
 
             if (!InitWindowing())
             {
@@ -124,9 +124,9 @@ namespace Robust.Client.Graphics.Clyde
         protected override void ReadConfig()
         {
             base.ReadConfig();
-            _lightmapDivider = _configurationManager.GetCVar(CVars.DisplayLightMapDivider);
-            _maxLightsPerScene = _configurationManager.GetCVar(CVars.DisplayMaxLightsPerScene);
-            _enableSoftShadows = _configurationManager.GetCVar(CVars.DisplaySoftShadows);
+            _lightmapDivider = ConfigurationManager.GetCVar(CVars.DisplayLightMapDivider);
+            _maxLightsPerScene = ConfigurationManager.GetCVar(CVars.DisplayMaxLightsPerScene);
+            _enableSoftShadows = ConfigurationManager.GetCVar(CVars.DisplaySoftShadows);
         }
 
         protected override void ReloadConfig()
@@ -238,7 +238,7 @@ namespace Robust.Client.Graphics.Clyde
 
         private (int major, int minor)? ParseGLOverrideVersion()
         {
-            var overrideGLVersion = _configurationManager.GetCVar(CVars.DisplayOGLOverrideVersion);
+            var overrideGLVersion = ConfigurationManager.GetCVar(CVars.DisplayOGLOverrideVersion);
             if (string.IsNullOrEmpty(overrideGLVersion))
             {
                 return null;
@@ -315,6 +315,11 @@ namespace Robust.Client.Graphics.Clyde
             UniformConstantsUBO = new GLUniformBuffer<UniformConstants>(this, BindingIndexUniformConstants, nameof(UniformConstantsUBO));
 
             CreateMainViewport();
+
+            screenBufferHandle = new GLHandle(GL.GenTexture());
+            GL.BindTexture(TextureTarget.Texture2D, screenBufferHandle.Handle);
+            ApplySampleParameters(TextureSampleParameters.Default);
+            ScreenBufferTexture = GenTexture(screenBufferHandle, _framebufferSize, true, null, TexturePixelType.Rgba32);
         }
 
         private void CreateMainViewport()

Robust.Client/Graphics/Clyde/ClydeHeadless.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using JetBrains.Annotations;
 using Robust.Client.Audio;
@@ -37,6 +38,13 @@ namespace Robust.Client.Graphics.Clyde
         public IClydeDebugInfo DebugInfo { get; } = new DummyDebugInfo();
         public IClydeDebugStats DebugStats { get; } = new DummyDebugStats();
 
+        public event Action<TextEventArgs>? TextEntered;
+        public event Action<MouseMoveEventArgs>? MouseMove;
+        public event Action<KeyEventArgs>? KeyUp;
+        public event Action<KeyEventArgs>? KeyDown;
+        public event Action<MouseWheelEventArgs>? MouseWheel;
+        public event Action<string>? CloseWindow;
+
         public Texture GetStockTexture(ClydeStockTexture stockTexture)
         {
             return new DummyTexture((1, 1));
@@ -63,6 +71,11 @@ namespace Robust.Client.Graphics.Clyde
             // Nada.
         }
 
+        public void SetWindowMonitor(IClydeMonitor monitor)
+        {
+            // Nada.
+        }
+
         public void RequestWindowAttention()
         {
             // Nada.
@@ -86,6 +99,12 @@ namespace Robust.Client.Graphics.Clyde
             remove { }
         }
 
+        public event Action OnWindowScaleChanged
+        {
+            add { }
+            remove { }
+        }
+
         public void Render()
         {
             // Nada.
@@ -101,7 +120,7 @@ namespace Robust.Client.Graphics.Clyde
             // Nada.
         }
 
-        public Texture LoadTextureFromPNGStream(Stream stream, string? name = null,
+        public OwnedTexture LoadTextureFromPNGStream(Stream stream, string? name = null,
             TextureLoadParameters? loadParams = null)
         {
             using (var image = Image.Load<Rgba32>(stream))
@@ -110,7 +129,7 @@ namespace Robust.Client.Graphics.Clyde
             }
         }
 
-        public Texture LoadTextureFromImage<T>(Image<T> image, string? name = null,
+        public OwnedTexture LoadTextureFromImage<T>(Image<T> image, string? name = null,
             TextureLoadParameters? loadParams = null) where T : unmanaged, IPixel<T>
         {
             return new DummyTexture((image.Width, image.Height));
@@ -156,6 +175,12 @@ namespace Robust.Client.Graphics.Clyde
             return new Viewport();
         }
 
+        public IEnumerable<IClydeMonitor> EnumerateMonitors()
+        {
+            // TODO: Actually return something.
+            yield break;
+        }
+
         public ClydeHandle LoadShader(ParsedShader shader, string? name = null)
         {
             return default;
@@ -267,6 +292,11 @@ namespace Robust.Client.Graphics.Clyde
             {
                 // Nada.
             }
+
+            public void SetVelocity(Vector2 velocity)
+            {
+                // Nada.
+            }
         }
 
         private sealed class DummyBufferedAudioSource : DummyAudioSource, IClydeBufferedAudioSource

Robust.Client/Graphics/Clyde/GLObjects/Clyde.ShaderProgram.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using OpenToolkit.Graphics.OpenGL4;

Robust.Client/Graphics/Clyde/Shaders/base-default.frag

@@ -4,7 +4,6 @@ varying highp vec2 Pos;
 uniform sampler2D lightMap;
 uniform highp vec4 modulate;
 
-#line 1000
 // [SHADER_HEADER_CODE]
 
 void main()
@@ -13,7 +12,6 @@ void main()
 
     lowp vec4 COLOR;
 
-    #line 10000
     // [SHADER_CODE]
 
     lowp vec3 lightSample = texture2D(lightMap, Pos).rgb;

Robust.Client/Graphics/Clyde/Shaders/z-library.glsl

@@ -89,9 +89,10 @@ uniform highp vec2 TEXTURE_PIXEL_SIZE;
 // -- srgb emulation --
 
 #ifdef HAS_SRGB
-highp vec4 zTexture(highp vec2 uv)
+
+highp vec4 zTextureSpec(sampler2D tex, highp vec2 uv)
 {
-    return texture2D(TEXTURE, uv);
+    return texture2D(tex, uv);
 }
 
 highp vec4 zAdjustResult(highp vec4 col)
@@ -101,9 +102,9 @@ highp vec4 zAdjustResult(highp vec4 col)
 #else
 uniform lowp vec2 SRGB_EMU_CONFIG;
 
-highp vec4 zTexture(highp vec2 uv)
+highp vec4 zTextureSpec(sampler2D tex, highp vec2 uv)
 {
-    highp vec4 col = texture2D(TEXTURE, uv);
+    highp vec4 col = texture2D(tex, uv);
     if (SRGB_EMU_CONFIG.x > 0.5)
     {
         return zFromSrgb(col);
@@ -121,5 +122,10 @@ highp vec4 zAdjustResult(highp vec4 col)
 }
 #endif
 
+highp vec4 zTexture(highp vec2 uv)
+{
+    return zTextureSpec(TEXTURE, uv);
+}
+
 // -- Utilities End --
 

Robust.Client/Graphics/ClydeBase.cs

@@ -18,8 +18,7 @@ namespace Robust.Client.Graphics
     /// </summary>
     internal abstract class ClydeBase
     {
-        [Dependency] protected readonly IConfigurationManager _configurationManager = default!;
-        [Dependency] protected readonly IGameControllerInternal _gameController = default!;
+        [Dependency] protected readonly IConfigurationManager ConfigurationManager = default!;
 
         protected WindowMode WindowMode { get; private set; } = WindowMode.Windowed;
         protected bool VSync { get; private set; } = true;
@@ -31,11 +30,11 @@ namespace Robust.Client.Graphics
 
         public virtual bool Initialize()
         {
-            _configurationManager.OnValueChanged(CVars.DisplayVSync, _vSyncChanged, true);
-            _configurationManager.OnValueChanged(CVars.DisplayWindowMode, _windowModeChanged, true);
-            _configurationManager.OnValueChanged(CVars.DisplayLightMapDivider, LightmapDividerChanged, true);
-            _configurationManager.OnValueChanged(CVars.DisplayMaxLightsPerScene, MaxLightsPerSceneChanged, true);
-            _configurationManager.OnValueChanged(CVars.DisplaySoftShadows, SoftShadowsChanged, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplayVSync, _vSyncChanged, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplayWindowMode, _windowModeChanged, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplayLightMapDivider, LightmapDividerChanged, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplayMaxLightsPerScene, MaxLightsPerSceneChanged, true);
+            ConfigurationManager.OnValueChanged(CVars.DisplaySoftShadows, SoftShadowsChanged, true);
 
             return true;
         }
@@ -51,8 +50,8 @@ namespace Robust.Client.Graphics
 
         protected virtual void ReadConfig()
         {
-            WindowMode = (WindowMode) _configurationManager.GetCVar(CVars.DisplayWindowMode);
-            VSync = _configurationManager.GetCVar(CVars.DisplayVSync);
+            WindowMode = (WindowMode) ConfigurationManager.GetCVar(CVars.DisplayWindowMode);
+            VSync = ConfigurationManager.GetCVar(CVars.DisplayVSync);
         }
 
         private void _vSyncChanged(bool newValue)

Robust.Client/Graphics/Font.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Text;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -40,63 +41,48 @@ namespace Robust.Client.Graphics
             return GetLineHeight(scale) - GetHeight(scale);
         }
 
-        [Obsolete("Use GetAscent")] public int Ascent => GetAscent(1);
-        [Obsolete("Use GetHeight")] public int Height => GetHeight(1);
-        [Obsolete("Use GetDescent")] public int Descent => GetDescent(1);
-        [Obsolete("Use GetLineHeight")] public int LineHeight => GetLineHeight(1);
-        [Obsolete("Use GetLineSeparation")] public int LineSeparation => GetLineSeparation(1);
-
-        // Yes, I am aware that using char is bad.
-        // At the same time the font system is nowhere close to rendering Unicode so...
         /// <summary>
         ///     Draw a character at a certain baseline position on screen.
         /// </summary>
         /// <param name="handle">The drawing handle to draw to.</param>
-        /// <param name="chr">
-        ///     The Unicode code point to draw. Yes I'm aware about UTF-16 being crap,
-        ///     do you think this system can draw anything except ASCII?
-        /// </param>
+        /// <param name="rune">The Unicode code point to draw.</param>
         /// <param name="baseline">The baseline from which to draw the character.</param>
+        /// <param name="scale">DPI scale factor to render the font at.</param>
         /// <param name="color">The color of the character to draw.</param>
+        /// <param name="fallback">If the character is not available, render "<22>" instead.</param>
         /// <returns>How much to advance the cursor to draw the next character.</returns>
-        [Obsolete("Use DrawChar with scale support.")]
-        public float DrawChar(DrawingHandleScreen handle, char chr, Vector2 baseline, Color color)
-        {
-            return DrawChar(handle, chr, baseline, 1, color);
-        }
+        public abstract float DrawChar(
+            DrawingHandleScreen handle, Rune rune, Vector2 baseline, float scale,
+            Color color, bool fallback=true);
 
-        public abstract float DrawChar(DrawingHandleScreen handle, char chr, Vector2 baseline, float scale,
-            Color color);
+        [Obsolete("Use Rune variant instead")]
+        public float DrawChar(DrawingHandleScreen handle, char chr, Vector2 baseline, float scale, Color color)
+        {
+            return DrawChar(handle, (Rune) chr, baseline, scale, color);
+        }
 
         /// <summary>
         ///     Gets metrics describing the dimensions and positioning of a single glyph in the font.
         /// </summary>
-        /// <param name="chr">The character to fetch the glyph metrics for.</param>
+        /// <param name="rune">The unicode codepoint to fetch the glyph metrics for.</param>
+        /// <param name="scale">DPI scale factor to render the font at.</param>
+        /// <param name="fallback">
+        ///     If the character is not available, return data for "<22>" instead.
+        ///     This can still fail if the font does not define <20> itself.
+        /// </param>
         /// <returns>
         ///     <c>null</c> if this font does not have a glyph for the specified character,
         ///     otherwise the metrics you asked for.
         /// </returns>
         /// <seealso cref="TryGetCharMetrics"/>
-        [Obsolete("Use GetCharMetrics with scale support.")]
-        public CharMetrics? GetCharMetrics(char chr)
-        {
-            return GetCharMetrics(chr, 1);
-        }
-
-        public abstract CharMetrics? GetCharMetrics(char chr, float scale);
+        public abstract CharMetrics? GetCharMetrics(Rune rune, float scale, bool fallback=true);
 
         /// <summary>
         ///     Try-pattern version of <see cref="GetCharMetrics"/>.
         /// </summary>
-        [Obsolete("Use TryGetCharMetrics with scale support.")]
-        public bool TryGetCharMetrics(char chr, out CharMetrics metrics)
+        public bool TryGetCharMetrics(Rune rune, float scale, out CharMetrics metrics, bool fallback=true)
         {
-            return TryGetCharMetrics(chr, 1, out metrics);
-        }
-
-        public bool TryGetCharMetrics(char chr, float scale, out CharMetrics metrics)
-        {
-            var maybe = GetCharMetrics(chr, scale);
+            var maybe = GetCharMetrics(rune, scale);
             if (maybe.HasValue)
             {
                 metrics = maybe.Value;
@@ -128,15 +114,23 @@ namespace Robust.Client.Graphics
         public override int GetDescent(float scale) => Handle.GetDescent(scale);
         public override int GetLineHeight(float scale) => Handle.GetLineHeight(scale);
 
-        public override float DrawChar(DrawingHandleScreen handle, char chr, Vector2 baseline, float scale, Color color)
+        public override float DrawChar(DrawingHandleScreen handle, Rune rune, Vector2 baseline, float scale, Color color, bool fallback=true)
         {
-            var metrics = Handle.GetCharMetrics(chr, scale);
+            var metrics = Handle.GetCharMetrics(rune, scale);
             if (!metrics.HasValue)
             {
-                return 0;
+                if (fallback && !Rune.IsWhiteSpace(rune))
+                {
+                    rune = new Rune('<27>');
+                    metrics = Handle.GetCharMetrics(rune, scale);
+                    if (!metrics.HasValue)
+                        return 0;
+                }
+                else
+                    return 0;
             }
 
-            var texture = Handle.GetCharTexture(chr, scale);
+            var texture = Handle.GetCharTexture(rune, scale);
             if (texture == null)
             {
                 return metrics.Value.Advance;
@@ -147,9 +141,12 @@ namespace Robust.Client.Graphics
             return metrics.Value.Advance;
         }
 
-        public override CharMetrics? GetCharMetrics(char chr, float scale)
+        public override CharMetrics? GetCharMetrics(Rune rune, float scale, bool fallback=true)
         {
-            return Handle.GetCharMetrics(chr, scale);
+            var metrics = Handle.GetCharMetrics(rune, scale);
+            if (metrics == null && !Rune.IsWhiteSpace(rune) && fallback)
+                return Handle.GetCharMetrics(new Rune('<27>'), scale);
+            return metrics;
         }
     }
 
@@ -160,13 +157,13 @@ namespace Robust.Client.Graphics
         public override int GetDescent(float scale) => default;
         public override int GetLineHeight(float scale) => default;
 
-        public override float DrawChar(DrawingHandleScreen handle, char chr, Vector2 baseline, float scale, Color color)
+        public override float DrawChar(DrawingHandleScreen handle, Rune rune, Vector2 baseline, float scale, Color color, bool fallback=true)
         {
             // Nada, it's a dummy after all.
             return 0;
         }
 
-        public override CharMetrics? GetCharMetrics(char chr, float scale)
+        public override CharMetrics? GetCharMetrics(Rune rune, float scale, bool fallback=true)
         {
             // Nada, it's a dummy after all.
             return null;

Robust.Client/Graphics/FontManager.cs

@@ -4,9 +4,6 @@ using System.IO;
 using System.Text;
 using JetBrains.Annotations;
 using Robust.Client.Utility;
-using Robust.Shared;
-using Robust.Shared.Configuration;
-using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using SharpFont;
@@ -20,18 +17,18 @@ namespace Robust.Client.Graphics
         private const int SheetWidth = 256;
         private const int SheetHeight = 256;
 
-        [Dependency] private readonly IConfigurationManager _configuration = default!;
-        [Dependency] private readonly IClyde _clyde = default!;
+        private readonly IClyde _clyde;
 
-        private uint BaseFontDPI;
+        private uint _baseFontDpi = 96;
 
         private readonly Library _library;
 
         private readonly Dictionary<(FontFaceHandle, int fontSize), FontInstanceHandle> _loadedInstances =
             new();
 
-        public FontManager()
+        public FontManager(IClyde clyde)
         {
+            _clyde = clyde;
             _library = new Library();
         }
 
@@ -42,9 +39,9 @@ namespace Robust.Client.Graphics
             return handle;
         }
 
-        void IFontManagerInternal.Initialize()
+        void IFontManagerInternal.SetFontDpi(uint fontDpi)
         {
-            BaseFontDPI = (uint) _configuration.GetCVar(CVars.DisplayFontDpi);
+            _baseFontDpi = fontDpi;
         }
 
         public IFontInstanceHandle MakeInstance(IFontFaceHandle handle, int size)
@@ -64,7 +61,7 @@ namespace Robust.Client.Graphics
         private ScaledFontData _generateScaledDatum(FontInstanceHandle instance, float scale)
         {
             var ftFace = instance.FaceHandle.Face;
-            ftFace.SetCharSize(0, instance.Size, 0, (uint) (BaseFontDPI * scale));
+            ftFace.SetCharSize(0, instance.Size, 0, (uint) (_baseFontDpi * scale));
 
             var ascent = ftFace.Size.Metrics.Ascender.ToInt32();
             var descent = -ftFace.Size.Metrics.Descender.ToInt32();
@@ -83,7 +80,7 @@ namespace Robust.Client.Graphics
                 return;
 
             var face = instance.FaceHandle.Face;
-            face.SetCharSize(0, instance.Size, 0, (uint) (BaseFontDPI * scale));
+            face.SetCharSize(0, instance.Size, 0, (uint) (_baseFontDpi * scale));
             face.LoadGlyph(glyph, LoadFlags.Default, LoadTarget.Normal);
             face.Glyph.RenderGlyph(RenderMode.Normal);
 
@@ -189,7 +186,7 @@ namespace Robust.Client.Graphics
             OwnedTexture GenSheet()
             {
                 var sheet = _clyde.CreateBlankTexture<A8>((SheetWidth, SheetHeight),
-                    $"font-{face.FamilyName}-{instance.Size}-{(uint) (BaseFontDPI * scale)}-sheet{scaled.AtlasTextures.Count}");
+                    $"font-{face.FamilyName}-{instance.Size}-{(uint) (_baseFontDpi * scale)}-sheet{scaled.AtlasTextures.Count}");
                 scaled.AtlasTextures.Add(sheet);
                 return sheet;
             }

Robust.Client/Graphics/IClyde.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using Robust.Shared.Maths;
@@ -21,6 +22,7 @@ namespace Robust.Client.Graphics
         Vector2 DefaultWindowScale { get; }
 
         void SetWindowTitle(string title);
+        void SetWindowMonitor(IClydeMonitor monitor);
 
         /// <summary>
         ///     This is the magic method to make the game window ping you in the task bar.
@@ -31,10 +33,12 @@ namespace Robust.Client.Graphics
 
         event Action<WindowFocusedEventArgs> OnWindowFocused;
 
-        Texture LoadTextureFromPNGStream(Stream stream, string? name = null,
+        event Action OnWindowScaleChanged;
+
+        OwnedTexture LoadTextureFromPNGStream(Stream stream, string? name = null,
             TextureLoadParameters? loadParams = null);
 
-        Texture LoadTextureFromImage<T>(Image<T> image, string? name = null,
+        OwnedTexture LoadTextureFromImage<T>(Image<T> image, string? name = null,
             TextureLoadParameters? loadParams = null) where T : unmanaged, IPixel<T>;
 
         /// <summary>
@@ -104,6 +108,8 @@ namespace Robust.Client.Graphics
         }
 
         IClydeViewport CreateViewport(Vector2i size, string? name = null);
+
+        IEnumerable<IClydeMonitor> EnumerateMonitors();
     }
 
     // TODO: Maybe implement IDisposable for render targets. I got lazy and didn't.

Robust.Client/Graphics/IClydeAudioSource.cs

@@ -20,5 +20,6 @@ namespace Robust.Client.Graphics
         void SetVolume(float decibels);
         void SetOcclusion(float blocks);
         void SetPlaybackPosition(float seconds);
+        void SetVelocity(Vector2 velocity);
     }
 }

Robust.Client/Graphics/IClydeInternal.cs

@@ -1,3 +1,4 @@
+using System;
 using Robust.Client.Input;
 using Robust.Client.UserInterface;
 using Robust.Shared.Maths;
@@ -16,6 +17,13 @@ namespace Robust.Client.Graphics
         bool Initialize();
         void Ready();
 
+        event Action<TextEventArgs> TextEntered;
+        event Action<MouseMoveEventArgs> MouseMove;
+        event Action<KeyEventArgs> KeyUp;
+        event Action<KeyEventArgs> KeyDown;
+        event Action<MouseWheelEventArgs> MouseWheel;
+        event Action<string> CloseWindow;
+
         ClydeHandle LoadShader(ParsedShader shader, string? name = null);
 
         void ReloadShader(ClydeHandle handle, ParsedShader newShader);

Robust.Client/Graphics/IClydeMonitor.cs

@@ -0,0 +1,18 @@
+using Robust.Shared.Maths;
+
+namespace Robust.Client.Graphics
+{
+    /// <summary>
+    ///     Represents a connected monitor on the user's system.
+    /// </summary>
+    public interface IClydeMonitor
+    {
+        /// <summary>
+        ///     This ID is not consistent between startups of the game.
+        /// </summary>
+        int Id { get; }
+        string Name { get; }
+        Vector2i Size { get; }
+        int RefreshRate { get; }
+    }
+}

Robust.Client/Graphics/IFontManager.cs

@@ -12,7 +12,7 @@ namespace Robust.Client.Graphics
     {
         IFontFaceHandle Load(Stream stream);
         IFontInstanceHandle MakeInstance(IFontFaceHandle handle, int size);
-        void Initialize();
+        void SetFontDpi(uint fontDpi);
     }
 
     internal interface IFontFaceHandle

Robust.Client/Graphics/Overlays/IOverlayManager.cs

@@ -1,22 +1,29 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using JetBrains.Annotations;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.Graphics
 {
+
     [PublicAPI]
     public interface IOverlayManager
     {
-        void AddOverlay(Overlay overlay);
-        void RemoveOverlay(string id);
-        bool HasOverlay(string id);
+        bool AddOverlay(Overlay overlay);
 
-        Overlay GetOverlay(string id);
-        T GetOverlay<T>(string id) where T : Overlay;
+        bool RemoveOverlay(Overlay overlay);
+        bool RemoveOverlay(Type overlayClass);
+        bool RemoveOverlay<T>() where T : Overlay;
 
-        bool TryGetOverlay(string id, [NotNullWhen(true)] out Overlay? overlay);
-        bool TryGetOverlay<T>(string id, [NotNullWhen(true)] out T? overlay) where T : Overlay;
+        bool TryGetOverlay(Type overlayClass, out Overlay? overlay);
+        bool TryGetOverlay<T>(out T? overlay) where T : Overlay;
+
+        Overlay GetOverlay(Type overlayClass);
+        T GetOverlay<T>() where T : Overlay;
+
+        bool HasOverlay(Type overlayClass);
+        bool HasOverlay<T>() where T : Overlay;
 
         IEnumerable<Overlay> AllOverlays { get; }
     }

Robust.Client/Graphics/Overlays/Overlay.cs

@@ -1,65 +1,54 @@
-using System;
-using System.Collections.Generic;
-using JetBrains.Annotations;
 using Robust.Shared.IoC;
+using JetBrains.Annotations;
 using Robust.Shared.Timing;
+using Robust.Shared.Enums;
+using System;
 
 namespace Robust.Client.Graphics
 {
     /// <summary>
-    ///     An overlay is used for fullscreen drawing in the game, for example parallax.
+    ///     An overlay is used for fullscreen drawing in the game. This can range from drawing parallax to a full screen shader.
     /// </summary>
     [PublicAPI]
     public abstract class Overlay
     {
+
         /// <summary>
-        ///     The ID of this overlay. This is used to identify it inside the <see cref="IOverlayManager"/>.
+        ///     Determines when this overlay is drawn in the rendering queue.
         /// </summary>
-        public string ID { get; }
-
-        public virtual bool AlwaysDirty => false;
-        public bool IsDirty => AlwaysDirty || _isDirty;
-        public bool Drawing { get; private set; }
-
         public virtual OverlaySpace Space => OverlaySpace.ScreenSpace;
 
+        /// <summary>
+        ///     If set to true, <see cref="ScreenTexture"/> will be set to the current frame (at the moment before the overlay is rendered). This can be costly to performance, but
+        ///     some shaders will require it as a passed in uniform to operate.
+        /// </summary>
+        public virtual bool RequestScreenTexture => false;
+
+        /// <summary>
+        ///     If <see cref="RequestScreenTexture"> is true, then this will be set to the texture corresponding to the current frame. If false, it will always be null.
+        /// </summary>
+        public Texture? ScreenTexture = null;
+
+        /// <summary>
+        ///    Overlays on the same OverlaySpace will be drawn from lowest ZIndex to highest ZIndex. As an example, ZIndex -1 will be drawn before ZIndex 2.
+        ///    This value is 0 by default. Overlays with same ZIndex will be drawn in an random order.
+        /// </summary>
+        public int? ZIndex { get; set; }
+
         protected IOverlayManager OverlayManager { get; }
 
-        public int? ZIndex { get; set; }
+        private bool Disposed = false;
 
-        public virtual bool SubHandlesUseMainShader { get; } = true;
-
-        private bool _isDirty = true;
-
-        private readonly List<DrawingHandleBase> TempHandles = new();
-
-        private bool Disposed;
-
-        protected Overlay(string id)
+        public Overlay()
         {
             OverlayManager = IoCManager.Resolve<IOverlayManager>();
-            ID = id;
         }
 
-        public void Dispose()
-        {
-            if (Disposed)
-            {
-                return;
-            }
-
-            Dispose(true);
-            Disposed = true;
-            GC.SuppressFinalize(this);
-        }
-
-        ~Overlay()
-        {
-            Dispose(false);
-        }
-
-        protected virtual void Dispose(bool disposing)
-        {
+        /// <summary>
+        ///     If this function returns true, the target framebuffer will be wiped before applying this overlay to it.
+        /// </summary>
+        public virtual bool OverwriteTargetFrameBuffer(){
+            return false;
         }
 
         /// <summary>
@@ -69,50 +58,34 @@ namespace Robust.Client.Graphics
         /// <param name="currentSpace">Current space that is being drawn. This function is called for every space that was set up in initialization.</param>
         protected abstract void Draw(DrawingHandleBase handle, OverlaySpace currentSpace);
 
-        public void Dirty()
-        {
-            _isDirty = true;
+        protected internal virtual void FrameUpdate(FrameEventArgs args) { }
+
+        ~Overlay() {
+            Dispose();
+        }
+
+        public void Dispose() {
+            if (Disposed) 
+                return;
+            else
+                DisposeBehavior();
+        }
+
+        protected virtual void DisposeBehavior(){
+            Disposed = true;
+            GC.SuppressFinalize(this);
         }
 
-        protected internal virtual void FrameUpdate(FrameEventArgs args) { }
 
         internal void ClydeRender(IRenderHandle renderHandle, OverlaySpace currentSpace)
         {
             DrawingHandleBase handle;
-            if (currentSpace == OverlaySpace.WorldSpace)
-                handle = renderHandle.DrawingHandleWorld;
-            else
+            if (currentSpace == OverlaySpace.ScreenSpace || currentSpace == OverlaySpace.ScreenSpaceBelowWorld)
                 handle = renderHandle.DrawingHandleScreen;
+            else
+                handle = renderHandle.DrawingHandleWorld;
 
             Draw(handle, currentSpace);
         }
     }
-
-
-    /// <summary>
-    ///     Determines in which canvas layers an overlay gets drawn.
-    /// </summary>
-    [Flags]
-    public enum OverlaySpace : byte
-    {
-        /// <summary>
-        ///     Used for matching bit flags.
-        /// </summary>
-        None = 0b0000,
-
-        /// <summary>
-        ///     This overlay will be drawn in the UI root, thus being in screen space.
-        /// </summary>
-        ScreenSpace = 0b0001,
-
-        /// <summary>
-        ///     This overlay will be drawn in the world root, thus being in world space.
-        /// </summary>
-        WorldSpace = 0b0010,
-
-        /// <summary>
-        ///     Drawn in screen coordinates, but behind the world.
-        /// </summary>
-        ScreenSpaceBelowWorld = 0b0100,
-    }
 }

Robust.Client/Graphics/Overlays/OverlayManager.cs

@@ -1,13 +1,15 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using Robust.Shared.Log;
 using Robust.Shared.Timing;
 
 namespace Robust.Client.Graphics
 {
     internal class OverlayManager : IOverlayManagerInternal
     {
-        private readonly Dictionary<string, Overlay> _overlays = new();
+        private readonly Dictionary<Type, Overlay> _overlays = new Dictionary<Type, Overlay>();
+        public IEnumerable<Overlay> AllOverlays => _overlays.Values;
 
         public void FrameUpdate(FrameEventArgs args)
         {
@@ -17,59 +19,80 @@ namespace Robust.Client.Graphics
             }
         }
 
-        public void AddOverlay(Overlay overlay)
+        public bool AddOverlay(Overlay overlay)
         {
-            if (_overlays.ContainsKey(overlay.ID))
-            {
-                throw new InvalidOperationException($"We already have an overlay with ID '{overlay.ID}'");
+            if(_overlays.ContainsKey(overlay.GetType()))
+                return false;
+            _overlays.Add(overlay.GetType(), overlay);
+            return true;
+        }
+
+
+
+        public bool RemoveOverlay(Type overlayClass)
+        {
+            if(!overlayClass.IsSubclassOf(typeof(Overlay))){
+                Logger.Error("RemoveOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+                return false;
             }
-
-            _overlays.Add(overlay.ID, overlay);
+            return _overlays.Remove(overlayClass);
         }
 
-        public Overlay GetOverlay(string id)
-        {
-            return _overlays[id];
+        public bool RemoveOverlay<T>() where T : Overlay{
+            return RemoveOverlay(typeof(T));
         }
 
-        public T GetOverlay<T>(string id) where T : Overlay
-        {
-            return (T) GetOverlay(id);
+        public bool RemoveOverlay(Overlay overlay) {
+            return _overlays.Remove(overlay.GetType());
         }
 
-        public bool HasOverlay(string id)
-        {
-            return _overlays.ContainsKey(id);
-        }
 
-        public void RemoveOverlay(string id)
+
+
+
+        public bool TryGetOverlay(Type overlayClass, [NotNullWhen(true)] out Overlay? overlay)
         {
-            if (!_overlays.TryGetValue(id, out var overlay))
-            {
-                return;
+            overlay = null;
+            if (!overlayClass.IsSubclassOf(typeof(Overlay))){
+                Logger.Error("TryGetOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+                return false;
             }
-
-            overlay.Dispose();
-            _overlays.Remove(id);
+            return _overlays.TryGetValue(overlayClass, out overlay);
         }
 
-        public bool TryGetOverlay(string id, [NotNullWhen(true)] out Overlay? overlay)
-        {
-            return _overlays.TryGetValue(id, out overlay);
-        }
-
-        public bool TryGetOverlay<T>(string id, [NotNullWhen(true)] out T? overlay) where T : Overlay
-        {
-            if (_overlays.TryGetValue(id, out var value))
-            {
-                overlay = (T) value;
+        public bool TryGetOverlay<T>([NotNullWhen(true)] out T? overlay) where T : Overlay {
+            overlay = null;
+            if(_overlays.TryGetValue(typeof(T), out Overlay? toReturn)){
+                overlay = (T)toReturn;
                 return true;
             }
-
-            overlay = default;
             return false;
         }
 
-        public IEnumerable<Overlay> AllOverlays => _overlays.Values;
+
+
+
+        public Overlay GetOverlay(Type overlayClass) {
+            return _overlays[overlayClass];
+        }
+
+        public T GetOverlay<T>() where T : Overlay {
+            return (T)_overlays[typeof(T)];
+        }
+
+
+
+
+
+        public bool HasOverlay(Type overlayClass) {
+            if (!overlayClass.IsSubclassOf(typeof(Overlay)))
+                Logger.Error("HasOverlay was called with arg: " + overlayClass.ToString() + ", which is not a subclass of Overlay!");
+            return _overlays.ContainsKey(overlayClass);
+        }
+
+        public bool HasOverlay<T>() where T : Overlay  {
+            return _overlays.ContainsKey(typeof(T));
+        }
+
     }
 }

Robust.Client/Graphics/RSI/RSI.State.cs

@@ -19,10 +19,10 @@ namespace Robust.Client.Graphics
         public sealed class State : IRsiStateLike
         {
             // List of delays for the frame to reach the next frame.
-            private readonly float[] Delays;
+            public readonly float[] Delays;
 
             // 2D array for the texture to use for each animation frame at each direction.
-            private readonly Texture[][] Icons;
+            public readonly Texture[][] Icons;
 
             internal State(Vector2i size, StateId stateId, DirectionType direction, float[] delays, Texture[][] icons)
             {

Robust.Client/Graphics/RSI/RSISchema.json

@@ -1,47 +0,0 @@
-{
-    "$schema": "http://json-schema.org/draft-04/schema#",
-    "title": "RSI Image Format Validation Schema V1",
-    "description": "Robust Station Image",
-    "type": "object",
-    "definitions": {
-        "size": {
-            "type": "object",
-            "properties": {
-                "x": {"type": "integer", "minimum": 1},
-                "y": {"type": "integer", "minimum": 1}
-            },
-            "required": ["x","y"]
-        },
-        "directions": {
-            "type": "integer",
-            "enum": [1,4,8]
-        },
-        "state": {
-            "type": "object",
-            "properties": {
-                "name": {"type": "string"},
-                "flags": {"type": "object"}, //To be de-serialized as a Dictionary
-                "directions": {"$ref": "#/definitions/directions"},
-                "delays": {
-                    "type": "array",
-                    "minItems": 1,
-                    "items": {
-                        "type": "array",
-                        "items": {"type": "number", "minimum": 0, "exclusiveMinimum": true} //number == float
-                    }
-                }
-            },
-            "required": ["name"] //'delays' is marked as optional in the spec
-        }
-    },
-    "properties": {
-        "version": {"type": "integer", "minimum": 1, "maximum": 1},
-        "size": {"$ref": "#/definitions/size"},
-        "states": {
-            "type": "array",
-            "items": {"$ref": "#/definitions/state"},
-            "minItems": 1
-        }
-    },
-    "required": ["version","size","states"]
-}

Robust.Client/Input/Events.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Text;
 using Robust.Shared.Maths;
 
 namespace Robust.Client.Input
@@ -58,6 +59,7 @@ namespace Robust.Client.Input
         }
 
         public uint CodePoint { get; }
+        public Rune AsRune => new Rune(CodePoint);
     }
 
     public class KeyEventArgs : ModifierInputEventArgs

Robust.Client/Physics/DebugPhysicsIslandSystem.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using Robust.Client.Graphics;
 using Robust.Shared.Console;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
@@ -67,7 +68,7 @@ namespace Robust.Client.Physics
         public override void Shutdown()
         {
             base.Shutdown();
-            IoCManager.Resolve<IOverlayManager>().RemoveOverlay(nameof(PhysicsIslandOverlay));
+            IoCManager.Resolve<IOverlayManager>().RemoveOverlay(typeof(PhysicsIslandOverlay));
         }
 
         private void HandleIslandSolveMessage(IslandSolveMessage message)
@@ -94,7 +95,7 @@ namespace Robust.Client.Physics
 
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-        public PhysicsIslandOverlay() : base(nameof(PhysicsIslandOverlay))
+        public PhysicsIslandOverlay()
         {
             _islandSystem = EntitySystem.Get<DebugPhysicsIslandSystem>();
             _eyeManager = IoCManager.Resolve<IEyeManager>();

Robust.Client/Placement/PlacementOverlay.cs

@@ -1,5 +1,7 @@
+using Robust.Shared.Enums;
 using Robust.Client.Graphics;
 
+
 namespace Robust.Client.Placement
 {
     public partial class PlacementManager
@@ -7,10 +9,9 @@ namespace Robust.Client.Placement
         internal class PlacementOverlay : Overlay
         {
             private readonly PlacementManager _manager;
-            public override bool AlwaysDirty => true;
             public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-            public PlacementOverlay(PlacementManager manager) : base("placement")
+            public PlacementOverlay(PlacementManager manager)
             {
                 _manager = manager;
                 ZIndex = 100;

Robust.Client/Player/IPlayerManager.cs

@@ -21,7 +21,6 @@ namespace Robust.Client.Player
 
         void Initialize();
         void Startup(INetChannel channel);
-        void Update(float frameTime);
         void Shutdown();
 
         void ApplyPlayerStates(IEnumerable<PlayerState>? list);

Robust.Client/Player/PlayerManager.cs

@@ -95,12 +95,6 @@ namespace Robust.Client.Player
             _network.ClientSendMessage(msgList);
         }
 
-        /// <inheritdoc />
-        public void Update(float frameTime)
-        {
-            // Uh, nothing anymore I guess.
-        }
-
         /// <inheritdoc />
         public void Shutdown()
         {

Robust.Client/Properties/AssemblyInfo.cs

@@ -2,6 +2,7 @@
 
 [assembly: InternalsVisibleTo("Robust.UnitTesting")]
 [assembly: InternalsVisibleTo("Robust.Lite")]
+[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")]
 
 #if NET5_0
 [module: SkipLocalsInit]

Robust.Client/Prototypes/ClientPrototypeManager.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Threading;
@@ -53,20 +54,17 @@ namespace Robust.Client.Prototypes
         private void ReloadPrototypeQueue()
         {
 #if !FULL_RELEASE
-            var then = DateTime.Now;
+            var sw = Stopwatch.StartNew();
 
             var msg = NetManager.CreateNetMessage<MsgReloadPrototypes>();
             msg.Paths = _reloadQueue.ToArray();
             NetManager.ClientSendMessage(msg);
 
-            foreach (var path in _reloadQueue)
-            {
-                ReloadPrototypes(path);
-            }
+            ReloadPrototypes(_reloadQueue);
 
             _reloadQueue.Clear();
 
-            Logger.Info($"Reloaded prototypes in {(int) (DateTime.Now - then).TotalMilliseconds} ms");
+            Logger.Info($"Reloaded prototypes in {sw.ElapsedMilliseconds} ms");
 #endif
         }
 

Robust.Client/ResourceManagement/IResourceCacheInternal.cs

@@ -10,5 +10,6 @@ namespace Robust.Client.ResourceManagement
         void RsiLoaded(RsiLoadedEventArgs eventArgs);
 
         void MountLoaderApi(IFileApi api, string apiPrefix, ResourcePath? prefix=null);
+        void PreloadTextures();
     }
 }

Robust.Client/ResourceManagement/ResourceCache.Preload.cs

@@ -0,0 +1,196 @@
+using System;
+using System.Diagnostics;
+using System.Linq;
+using System.Threading.Tasks;
+using Robust.Client.Graphics;
+using Robust.Shared;
+using Robust.Shared.Configuration;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+
+namespace Robust.Client.ResourceManagement
+{
+    internal partial class ResourceCache
+    {
+        [Dependency] private readonly IClyde _clyde = default!;
+        [Dependency] private readonly ILogManager _logManager = default!;
+        [Dependency] private readonly IConfigurationManager _configurationManager = default!;
+
+        public void PreloadTextures()
+        {
+            var sawmill = _logManager.GetSawmill("res.preload");
+
+            if (!_configurationManager.GetCVar(CVars.TexturePreloadingEnabled))
+            {
+                sawmill.Debug($"Skipping texture preloading due to CVar value.");
+                return;
+            }
+
+            PreloadTextures(sawmill);
+            PreloadRsis(sawmill);
+        }
+
+        private void PreloadTextures(ISawmill sawmill)
+        {
+            sawmill.Debug("Preloading textures...");
+            var sw = Stopwatch.StartNew();
+            var resList = GetTypeDict<TextureResource>();
+
+            var texList = ContentFindFiles("/Textures/")
+                // Skip PNG files inside RSIs.
+                .Where(p => p.Extension == "png" && !p.ToString().Contains(".rsi/") && !resList.ContainsKey(p))
+                .Select(p => new TextureResource.LoadStepData {Path = p})
+                .ToArray();
+
+            Parallel.ForEach(texList, data =>
+            {
+                try
+                {
+                    TextureResource.LoadPreTexture(this, data);
+                }
+                catch (Exception e)
+                {
+                    // Mark failed loads as bad and skip them in the next few stages.
+                    // Avoids any silly array resizing or similar.
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                }
+            });
+
+            foreach (var data in texList)
+            {
+                if (data.Bad)
+                    continue;
+
+                try
+                {
+                    TextureResource.LoadTexture(_clyde, data);
+                }
+                catch (Exception e)
+                {
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                }
+            }
+
+            var errors = 0;
+            foreach (var data in texList)
+            {
+                if (data.Bad)
+                {
+                    errors += 1;
+                    continue;
+                }
+
+                try
+                {
+                    var texResource = new TextureResource();
+                    texResource.LoadFinish(this, data);
+                    resList[data.Path] = texResource;
+                }
+                catch (Exception e)
+                {
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                    errors += 1;
+                }
+            }
+
+            sawmill.Debug(
+                "Preloaded {CountLoaded} textures ({CountErrored} errored) in {LoadTime}",
+                texList.Length,
+                errors,
+                sw.Elapsed);
+        }
+
+        private void PreloadRsis(ISawmill sawmill)
+        {
+            var sw = Stopwatch.StartNew();
+            var resList = GetTypeDict<RSIResource>();
+
+            var rsiList = ContentFindFiles("/Textures/")
+                .Where(p => p.ToString().EndsWith(".rsi/meta.json"))
+                .Select(c => c.Directory)
+                .Where(p => !resList.ContainsKey(p))
+                .Select(p => new RSIResource.LoadStepData {Path = p})
+                .ToArray();
+
+            Parallel.ForEach(rsiList, data =>
+            {
+                try
+                {
+                    RSIResource.LoadPreTexture(this, data);
+                }
+                catch (Exception e)
+                {
+                    // Mark failed loads as bad and skip them in the next few stages.
+                    // Avoids any silly array resizing or similar.
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                }
+            });
+
+            foreach (var data in rsiList)
+            {
+                if (data.Bad)
+                    continue;
+
+                try
+                {
+                    RSIResource.LoadTexture(_clyde, data);
+                }
+                catch (Exception e)
+                {
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                }
+            }
+
+            Parallel.ForEach(rsiList, data =>
+            {
+                if (data.Bad)
+                    return;
+
+                try
+                {
+                    RSIResource.LoadPostTexture(data);
+                }
+                catch (Exception e)
+                {
+                    data.Bad = true;
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                }
+            });
+
+            var errors = 0;
+            foreach (var data in rsiList)
+            {
+                if (data.Bad)
+                {
+                    errors += 1;
+                    continue;
+                }
+
+                try
+                {
+                    var rsiRes = new RSIResource();
+                    rsiRes.LoadFinish(this, data);
+                    resList[data.Path] = rsiRes;
+                }
+                catch (Exception e)
+                {
+                    sawmill.Error($"Exception while loading RSI {data.Path}:\n{e}");
+                    data.Bad = true;
+                    errors += 1;
+                }
+            }
+
+            sawmill.Debug(
+                "Preloaded {CountLoaded} RSIs ({CountErrored} errored) in {LoadTime}",
+                rsiList.Length,
+                errors,
+                sw.Elapsed);
+
+        }
+    }
+}

Robust.Client/ResourceManagement/ResourceTypes/RSIResource.cs

@@ -2,17 +2,13 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Reflection;
+using System.Text.Json;
+using JetBrains.Annotations;
 using Robust.Client.Graphics;
 using Robust.Client.Utility;
-using Robust.Shared.Log;
+using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
-
-using Newtonsoft.Json.Linq;
-#if DEBUG
-using NJsonSchema;
-#endif
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -24,6 +20,14 @@ namespace Robust.Client.ResourceManagement
     /// </summary>
     public sealed class RSIResource : BaseResource
     {
+        private static readonly float[] OneArray = {1};
+
+        private static readonly JsonSerializerOptions SerializerOptions =
+            new JsonSerializerOptions(JsonSerializerDefaults.Web)
+            {
+                AllowTrailingCommas = true
+            };
+
         public RSI RSI { get; private set; } = default!;
 
         /// <summary>
@@ -38,64 +42,59 @@ namespace Robust.Client.ResourceManagement
 
         public override void Load(IResourceCache cache, ResourcePath path)
         {
-            var manifestPath = path / "meta.json";
-            string manifestContents;
+            var clyde = IoCManager.Resolve<IClyde>();
 
-            using (var manifestFile = cache.ContentFileRead(manifestPath))
-            using (var reader = new StreamReader(manifestFile))
-            {
-                manifestContents = reader.ReadToEnd();
-            }
+            var loadStepData = new LoadStepData {Path = path};
+            LoadPreTexture(cache, loadStepData);
 
-#if DEBUG
-            if (RSISchema != null)
-            {
-                var errors = RSISchema.Validate(manifestContents);
-                if (errors.Count != 0)
-                {
-                    Logger.Error($"Unable to load RSI from '{path}', {errors.Count} errors:");
+            // Load atlas.
+            LoadTexture(clyde, loadStepData);
 
-                    foreach (var error in errors)
-                    {
-                        Logger.Error("{0}", error.ToString());
-                    }
+            LoadPostTexture(loadStepData);
+            LoadFinish(cache, loadStepData);
 
-                    throw new RSILoadException($"{errors.Count} errors while loading RSI. See console.");
-                }
-            }
-#endif
+            loadStepData.AtlasSheet.Dispose();
+        }
 
-            // Ok schema validated just fine.
-            var manifestJson = JObject.Parse(manifestContents);
+        internal static void LoadTexture(IClyde clyde, LoadStepData loadStepData)
+        {
+            loadStepData.AtlasTexture = clyde.LoadTextureFromImage(
+                loadStepData.AtlasSheet,
+                loadStepData.Path.ToString());
+        }
 
-            var toAtlas = new List<(Image<Rgba32> src, Texture[][] output, int[][] indices, Vector2i[][] offsets, int totalFrameCount)>();
+        internal static void LoadPreTexture(IResourceCache cache, LoadStepData data)
+        {
+            var metadata = LoadRsiMetadata(cache, data.Path);
 
-            var metaData = ParseMetaData(manifestJson);
-            var frameSize = metaData.Size;
-            var rsi = new RSI(frameSize, path);
+            var stateCount = metadata.States.Length;
+            var toAtlas = new StateReg[stateCount];
 
-            var callbackOffsets = new Dictionary<RSI.StateId, Vector2i[][]>();
+            var frameSize = metadata.Size;
+            var rsi = new RSI(frameSize, data.Path);
+
+            var callbackOffsets = new Dictionary<RSI.StateId, Vector2i[][]>(stateCount);
 
             // Do every state.
-            foreach (var stateObject in metaData.States)
+            for (var index = 0; index < metadata.States.Length; index++)
             {
-                // Load image from disk.
-                var texPath = path / (stateObject.StateId + ".png");
-                var stream = cache.ContentFileRead(texPath);
-                Image<Rgba32> image;
-                using (stream)
-                {
-                    image = Image.Load<Rgba32>(stream);
-                }
-                var sheetSize = new Vector2i(image.Width, image.Height);
+                ref var reg = ref toAtlas[index];
 
-                if (sheetSize.X % frameSize.X != 0 || sheetSize.Y % frameSize.Y != 0)
+                var stateObject = metadata.States[index];
+                // Load image from disk.
+                var texPath = data.Path / (stateObject.StateId + ".png");
+                using (var stream = cache.ContentFileRead(texPath))
+                {
+                    reg.Src = Image.Load<Rgba32>(stream);
+                }
+
+                if (reg.Src.Width % frameSize.X != 0 || reg.Src.Height % frameSize.Y != 0)
                 {
                     throw new RSILoadException("State image size is not a multiple of the icon size.");
                 }
 
                 // Load all frames into a list so we can operate on it more sanely.
-                var frameCount = stateObject.Delays.Sum(delayList => delayList.Length);
+                reg.TotalFrameCount = stateObject.Delays.Sum(delayList => delayList.Length);
 
                 var (foldedDelays, foldedIndices) = FoldDelays(stateObject.Delays);
 
@@ -108,29 +107,34 @@ namespace Robust.Client.ResourceManagement
                     callbackOffset[i] = new Vector2i[foldedIndices[0].Length];
                 }
 
-                var state = new RSI.State(frameSize, stateObject.StateId, stateObject.DirType, foldedDelays, textures);
+                reg.Output = textures;
+                reg.Indices = foldedIndices;
+                reg.Offsets = callbackOffset;
+
+                var state = new RSI.State(frameSize, stateObject.StateId, stateObject.DirType, foldedDelays,
+                    textures);
                 rsi.AddState(state);
 
-                toAtlas.Add((image, textures, foldedIndices, callbackOffset, frameCount));
                 callbackOffsets[stateObject.StateId] = callbackOffset;
             }
 
             // Poorly hacked in texture atlas support here.
-            var totalFrameCount = toAtlas.Sum(p => p.totalFrameCount);
+            var totalFrameCount = toAtlas.Sum(p => p.TotalFrameCount);
 
             // Generate atlas.
             var dimensionX = (int) MathF.Ceiling(MathF.Sqrt(totalFrameCount));
             var dimensionY = (int) MathF.Ceiling((float) totalFrameCount / dimensionX);
 
-            using var sheet = new Image<Rgba32>(dimensionX * frameSize.X, dimensionY * frameSize.Y);
+            var sheet = new Image<Rgba32>(dimensionX * frameSize.X, dimensionY * frameSize.Y);
 
             var sheetIndex = 0;
-            foreach (var (src, _, _, _, frameCount) in toAtlas)
+            for (var index = 0; index < toAtlas.Length; index++)
             {
+                ref var reg = ref toAtlas[index];
                 // Blit all the frames over.
-                for (var i = 0; i < frameCount; i++)
+                for (var i = 0; i < reg.TotalFrameCount; i++)
                 {
-                    var srcWidth = (src.Width / frameSize.X);
+                    var srcWidth = (reg.Src.Width / frameSize.X);
                     var srcColumn = i % srcWidth;
                     var srcRow = i / srcWidth;
                     var srcPos = (srcColumn * frameSize.X, srcRow * frameSize.Y);
@@ -141,30 +145,49 @@ namespace Robust.Client.ResourceManagement
 
                     var srcBox = UIBox2i.FromDimensions(srcPos, frameSize);
 
-                    src.Blit(srcBox, sheet, sheetPos);
+                    reg.Src.Blit(srcBox, sheet, sheetPos);
                 }
 
-                sheetIndex += frameCount;
+                sheetIndex += reg.TotalFrameCount;
             }
 
-            // Load atlas.
-            var texture = Texture.LoadFromImage(sheet, path.ToString());
+            for (var i = 0; i < toAtlas.Length; i++)
+            {
+                ref var reg = ref toAtlas[i];
+                reg.Src.Dispose();
+            }
+
+            data.Rsi = rsi;
+            data.AtlasSheet = sheet;
+            data.AtlasList = toAtlas;
+            data.FrameSize = frameSize;
+            data.DimX = dimensionX;
+            data.CallbackOffsets = callbackOffsets;
+        }
+
+        internal static void LoadPostTexture(LoadStepData data)
+        {
+            var dimX = data.DimX;
+            var toAtlas = data.AtlasList;
+            var frameSize = data.FrameSize;
+            var texture = data.AtlasTexture;
 
             var sheetOffset = 0;
-            foreach (var (_, output, indices, offsets, frameCount) in toAtlas)
+            for (var toAtlasIndex = 0; toAtlasIndex < toAtlas.Length; toAtlasIndex++)
             {
-                for (var i = 0; i < indices.Length; i++)
+                ref var reg = ref toAtlas[toAtlasIndex];
+                for (var i = 0; i < reg.Indices.Length; i++)
                 {
-                    var dirIndices = indices[i];
-                    var dirOutput = output[i];
-                    var dirOffsets = offsets[i];
+                    var dirIndices = reg.Indices[i];
+                    var dirOutput = reg.Output[i];
+                    var dirOffsets = reg.Offsets[i];
 
                     for (var j = 0; j < dirIndices.Length; j++)
                     {
                         var index = sheetOffset + dirIndices[j];
 
-                        var sheetColumn = index % dimensionX;
-                        var sheetRow = index / dimensionX;
+                        var sheetColumn = index % dimX;
+                        var sheetRow = index / dimX;
                         var sheetPos = (sheetColumn * frameSize.X, sheetRow * frameSize.Y);
 
                         dirOffsets[j] = sheetPos;
@@ -172,22 +195,104 @@ namespace Robust.Client.ResourceManagement
                     }
                 }
 
-                sheetOffset += frameCount;
+                sheetOffset += reg.TotalFrameCount;
             }
+        }
 
-            foreach (var (image, _, _, _, _) in toAtlas)
-            {
-                image.Dispose();
-            }
-
-            RSI = rsi;
+        internal void LoadFinish(IResourceCache cache, LoadStepData data)
+        {
+            RSI = data.Rsi;
 
             if (cache is IResourceCacheInternal cacheInternal)
             {
-                cacheInternal.RsiLoaded(new RsiLoadedEventArgs(path, this, sheet, callbackOffsets));
+                cacheInternal.RsiLoaded(new RsiLoadedEventArgs(data.Path, this, data.AtlasSheet, data.CallbackOffsets));
             }
         }
 
+        private static RsiMetadata LoadRsiMetadata(IResourceCache cache, ResourcePath path)
+        {
+            var manifestPath = path / "meta.json";
+            string manifestContents;
+
+            using (var manifestFile = cache.ContentFileRead(manifestPath))
+            using (var reader = new StreamReader(manifestFile))
+            {
+                manifestContents = reader.ReadToEnd();
+            }
+
+            // Ok schema validated just fine.
+            var manifestJson = JsonSerializer.Deserialize<RsiJsonMetadata>(manifestContents, SerializerOptions);
+
+            if (manifestJson == null)
+                throw new RSILoadException("Manifest JSON was null!");
+
+            var size = manifestJson.Size;
+            var states = new StateMetadata[manifestJson.States.Length];
+
+            for (var stateI = 0; stateI < manifestJson.States.Length; stateI++)
+            {
+                var stateObject = manifestJson.States[stateI];
+                var stateName = stateObject.Name;
+                RSI.State.DirectionType directions;
+                int dirValue;
+
+                if (stateObject.Directions is { } dirVal)
+                {
+                    dirValue = dirVal;
+                    directions = dirVal switch
+                    {
+                        1 => RSI.State.DirectionType.Dir1,
+                        4 => RSI.State.DirectionType.Dir4,
+                        8 => RSI.State.DirectionType.Dir8,
+                        _ => throw new RSILoadException($"Invalid direction: {dirValue} expected 1, 4 or 8")
+                    };
+                }
+                else
+                {
+                    dirValue = 1;
+                    directions = RSI.State.DirectionType.Dir1;
+                }
+
+                // We can ignore selectors and flags for now,
+                // because they're not used yet!
+
+                // Get the lists of delays.
+                float[][] delays;
+                if (stateObject.Delays != null)
+                {
+                    delays = stateObject.Delays;
+
+                    if (delays.Length != dirValue)
+                    {
+                        throw new RSILoadException(
+                            "DirectionsdirectionFramesList count does not match amount of delays specified.");
+                    }
+
+                    for (var i = 0; i < delays.Length; i++)
+                    {
+                        var delayList = delays[i];
+                        if (delayList.Length == 0)
+                        {
+                            delays[i] = OneArray;
+                        }
+                    }
+                }
+                else
+                {
+                    delays = new float[dirValue][];
+                    // No delays specified, default to 1 frame per dir.
+                    for (var i = 0; i < dirValue; i++)
+                    {
+                        delays[i] = OneArray;
+                    }
+                }
+
+                states[stateI] = new StateMetadata(new RSI.StateId(stateName), directions, delays);
+            }
+
+            return new RsiMetadata(size, states);
+        }
+
         /// <summary>
         ///     Folds a per-directional sets of animation delays
         ///     into an equivalent set of animation delays and indices that works for every direction.
@@ -336,109 +441,38 @@ namespace Robust.Client.ResourceManagement
             return (floatDelays, arrayIndices);
         }
 
-        internal static RsiMetadata ParseMetaData(JObject manifestJson)
+        internal sealed class LoadStepData
         {
-            var size = manifestJson["size"]!.ToObject<Vector2i>();
-            var states = new List<StateMetadata>();
-
-            foreach (var stateObject in manifestJson["states"]!.Cast<JObject>())
-            {
-                var stateName = stateObject["name"]!.ToObject<string>()!;
-                RSI.State.DirectionType directions;
-                int dirValue;
-
-                if (stateObject.TryGetValue("directions", out var dirJToken))
-                {
-                    dirValue= dirJToken.ToObject<int>();
-                    directions = dirValue switch
-                    {
-                        1 => RSI.State.DirectionType.Dir1,
-                        4 => RSI.State.DirectionType.Dir4,
-                        8 => RSI.State.DirectionType.Dir8,
-                        _ => throw new RSILoadException($"Invalid direction: {dirValue} expected 1, 4 or 8")
-                    };
-                }
-                else
-                {
-                    dirValue = 1;
-                    directions = RSI.State.DirectionType.Dir1;
-                }
-
-                // We can ignore selectors and flags for now,
-                // because they're not used yet!
-
-                // Get the lists of delays.
-                float[][] delays;
-                if (stateObject.TryGetValue("delays", out var delayToken))
-                {
-                    delays = delayToken.ToObject<float[][]>()!;
-
-                    if (delays.Length != dirValue)
-                    {
-                        throw new RSILoadException(
-                            "DirectionsdirectionFramesList count does not match amount of delays specified.");
-                    }
-
-                    for (var i = 0; i < delays.Length; i++)
-                    {
-                        var delayList = delays[i];
-                        if (delayList.Length == 0)
-                        {
-                            delays[i] = new float[] {1};
-                        }
-                    }
-                }
-                else
-                {
-                    delays = new float[dirValue][];
-                    // No delays specified, default to 1 frame per dir.
-                    for (var i = 0; i < dirValue; i++)
-                    {
-                        delays[i] = new float[] {1};
-                    }
-                }
-
-                states.Add(new StateMetadata(new RSI.StateId(stateName), directions, delays));
-            }
-
-            return new RsiMetadata(size, states);
+            public bool Bad;
+            public ResourcePath Path = default!;
+            public Image<Rgba32> AtlasSheet = default!;
+            public int DimX;
+            public StateReg[] AtlasList = default!;
+            public Vector2i FrameSize;
+            public Dictionary<RSI.StateId, Vector2i[][]> CallbackOffsets = default!;
+            public Texture AtlasTexture = default!;
+            public RSI Rsi = default!;
         }
 
-#if DEBUG
-        private static readonly JsonSchema? RSISchema = GetSchema();
-
-        private static JsonSchema? GetSchema()
+        internal struct StateReg
         {
-            try
-            {
-                string schema;
-                using (var schemaStream = Assembly.GetExecutingAssembly()
-                    .GetManifestResourceStream("Robust.Client.Graphics.RSI.RSISchema.json")!)
-                using (var schemaReader = new StreamReader(schemaStream))
-                {
-                    schema = schemaReader.ReadToEnd();
-                }
-
-                return JsonSchema.FromJsonAsync(schema).Result;
-            }
-            catch (Exception e)
-            {
-                System.Console.WriteLine("Failed to load RSI JSON Schema!\n{0}", e);
-                return null;
-            }
+            public Image<Rgba32> Src;
+            public Texture[][] Output;
+            public int[][] Indices;
+            public Vector2i[][] Offsets;
+            public int TotalFrameCount;
         }
-#endif
 
         internal sealed class RsiMetadata
         {
-            public RsiMetadata(Vector2i size, List<StateMetadata> states)
+            public RsiMetadata(Vector2i size, StateMetadata[] states)
             {
                 Size = size;
                 States = states;
             }
 
             public Vector2i Size { get; }
-            public List<StateMetadata> States { get; }
+            public StateMetadata[] States { get; }
         }
 
         internal sealed class StateMetadata
@@ -466,6 +500,17 @@ namespace Robust.Client.ResourceManagement
 
             public float[][] Delays { get; }
         }
+
+        // To be directly deserialized.
+        [UsedImplicitly]
+        private sealed record RsiJsonMetadata(Vector2i Size, StateJsonMetadata[] States)
+        {
+        }
+
+        [UsedImplicitly]
+        private sealed record StateJsonMetadata(string Name, int? Directions, float[][]? Delays)
+        {
+        }
     }
 
     [Serializable]

Robust.Client/ResourceManagement/ResourceTypes/TextureResource.cs

@@ -1,7 +1,8 @@
 using System.IO;
+using System.Threading;
 using Robust.Client.Graphics;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
+using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
@@ -9,41 +10,52 @@ using YamlDotNet.RepresentationModel;
 
 namespace Robust.Client.ResourceManagement
 {
-    public class TextureResource : BaseResource
+    public sealed class TextureResource : BaseResource
     {
-        public const float ClickThreshold = 0.25f;
+        private OwnedTexture _texture = default!;
+        public override ResourcePath Fallback => new("/Textures/noSprite.png");
 
-        public override ResourcePath? Fallback => new("/Textures/noSprite.png");
-        public Texture Texture { get; private set; } = default!;
+        public Texture Texture => _texture;
 
         public override void Load(IResourceCache cache, ResourcePath path)
         {
-            if (!cache.TryContentFileRead(path, out var stream))
-            {
-                throw new FileNotFoundException("Content file does not exist for texture");
-            }
+            var clyde = IoCManager.Resolve<IClyde>();
 
-            using (stream)
-            {
-                // Primarily for tracking down iCCP sRGB errors in the image files.
-                Logger.DebugS("res.tex", $"Loading texture {path}.");
+            var data = new LoadStepData {Path = path};
 
-                var loadParameters = _tryLoadTextureParameters(cache, path) ?? TextureLoadParameters.Default;
-
-                var manager = IoCManager.Resolve<IClyde>();
-
-                using var image = Image.Load<Rgba32>(stream);
-
-                Texture = manager.LoadTextureFromImage(image, path.ToString(), loadParameters);
-
-                if (cache is IResourceCacheInternal cacheInternal)
-                {
-                    cacheInternal.TextureLoaded(new TextureLoadedEventArgs(path, image, this));
-                }
-            }
+            LoadPreTexture(cache, data);
+            LoadTexture(clyde, data);
+            LoadFinish(cache, data);
         }
 
-        private static TextureLoadParameters? _tryLoadTextureParameters(IResourceCache cache, ResourcePath path)
+        internal static void LoadPreTexture(IResourceCache cache, LoadStepData data)
+        {
+            using (var stream = cache.ContentFileRead(data.Path))
+            {
+                data.Image = Image.Load<Rgba32>(stream);
+            }
+
+            data.LoadParameters = TryLoadTextureParameters(cache, data.Path) ?? TextureLoadParameters.Default;
+        }
+
+        internal static void LoadTexture(IClyde clyde, LoadStepData data)
+        {
+            data.Texture = clyde.LoadTextureFromImage(data.Image, data.Path.ToString(), data.LoadParameters);
+        }
+
+        internal void LoadFinish(IResourceCache cache, LoadStepData data)
+        {
+            _texture = data.Texture;
+
+            if (cache is IResourceCacheInternal cacheInternal)
+            {
+                cacheInternal.TextureLoaded(new TextureLoadedEventArgs(data.Path, data.Image, this));
+            }
+
+            data.Image.Dispose();
+        }
+
+        private static TextureLoadParameters? TryLoadTextureParameters(IResourceCache cache, ResourcePath path)
         {
             var metaPath = path.WithName(path.Filename + ".yml");
             if (cache.TryContentFileRead(metaPath, out var stream))
@@ -70,6 +82,38 @@ namespace Robust.Client.ResourceManagement
             return null;
         }
 
+        public override void Reload(IResourceCache cache, ResourcePath path, CancellationToken ct = default)
+        {
+            var clyde = IoCManager.Resolve<IClyde>();
+
+            var data = new LoadStepData {Path = path};
+            LoadPreTexture(cache, data);
+
+            if (data.Image.Width == Texture.Width && data.Image.Height == Texture.Height)
+            {
+                // Dimensions match, rewrite texture in place.
+                _texture.SetSubImage(Vector2i.Zero, data.Image);
+            }
+            else
+            {
+                // Dimensions do not match, make new texture.
+                _texture.Dispose();
+                LoadTexture(clyde, data);
+                _texture = data.Texture;
+            }
+
+            data.Image.Dispose();
+        }
+
+        internal sealed class LoadStepData
+        {
+            public ResourcePath Path = default!;
+            public Image<Rgba32> Image = default!;
+            public TextureLoadParameters LoadParameters;
+            public OwnedTexture Texture = default!;
+            public bool Bad;
+        }
+
         // TODO: Due to a bug in Roslyn, NotNullIfNotNullAttribute doesn't work.
         // So this can't work with both nullables and non-nullables at the same time.
         // I decided to only have it work with non-nullables as such.

Robust.Client/Robust.Client.csproj

@@ -14,7 +14,6 @@
     <PackageReference Include="DiscordRichPresence" Version="1.0.175" />
     <PackageReference Include="JetBrains.Annotations" Version="2020.3.0" PrivateAssets="All" />
     <PackageReference Include="nfluidsynth" Version="0.3.1" />
-    <PackageReference Include="NJsonSchema" Version="10.3.8" />
     <PackageReference Include="NVorbis" Version="0.10.1" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
     <PackageReference Include="SixLabors.ImageSharp" Version="1.0.3" />
@@ -39,9 +38,6 @@
     <ProjectReference Include="..\Robust.Shared\Robust.Shared.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <EmbeddedResource Include="Graphics\RSI\RSISchema.json" Condition="'$(Configuration)' == 'Debug'">
-      <LogicalName>Robust.Client.Graphics.RSI.RSISchema.json</LogicalName>
-    </EmbeddedResource>
 
     <EmbeddedResource Include="Graphics\Clyde\Shaders\*" />
   </ItemGroup>

Robust.Client/State/IStateManager.cs

@@ -9,9 +9,7 @@ namespace Robust.Client.State
 
         State CurrentState { get; }
         void RequestStateChange<T>() where T : State, new();
-        void Update(FrameEventArgs e);
         void FrameUpdate(FrameEventArgs e);
-        void FormResize();
         void RequestStateChange(Type type);
     }
 }

Robust.Client/State/State.cs

@@ -1,4 +1,4 @@
-using Robust.Shared.Timing;
+using Robust.Shared.Timing;
 
 namespace Robust.Client.State
 {
@@ -14,16 +14,6 @@ namespace Robust.Client.State
         /// </summary>
         public abstract void Shutdown();
 
-        /// <summary>
-        ///     Update the contents of this screen.
-        /// </summary>
-        public virtual void Update(FrameEventArgs e) { }
-
         public virtual void FrameUpdate(FrameEventArgs e) { }
-
-        /// <summary>
-        ///     The screen has changed size, usually from resizing window. This is called automatically right after Startup.
-        /// </summary>
-        public virtual void FormResize() { }
     }
 }

Robust.Client/State/StateManager.cs

@@ -1,4 +1,4 @@
-using Robust.Shared.Log;
+using Robust.Shared.Log;
 using System;
 using Robust.Shared.IoC;
 using Robust.Shared.Timing;
@@ -17,21 +17,11 @@ namespace Robust.Client.State
             CurrentState = new DefaultState();
         }
 
-        public void Update(FrameEventArgs e)
-        {
-            CurrentState?.Update(e);
-        }
-
         public void FrameUpdate(FrameEventArgs e)
         {
             CurrentState?.FrameUpdate(e);
         }
 
-        public void FormResize()
-        {
-            CurrentState?.FormResize();
-        }
-
         public void RequestStateChange<T>() where T : State, new()
         {
             RequestStateChange(typeof(T));

Robust.Client/UserInterface/Control.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
@@ -817,25 +817,7 @@ namespace Robust.Client.UserInterface
         /// <summary>
         ///     Called when the size of the control changes.
         /// </summary>
-        protected virtual void Resized()
-        {
-        }
-
-        internal void DoUpdate(FrameEventArgs args)
-        {
-            Update(args);
-            foreach (var child in Children)
-            {
-                child.DoUpdate(args);
-            }
-        }
-
-        /// <summary>
-        ///     This is called every process frame.
-        /// </summary>
-        protected virtual void Update(FrameEventArgs args)
-        {
-        }
+        protected virtual void Resized() { }
 
         internal void DoFrameUpdate(FrameEventArgs args)
         {

Robust.Client/UserInterface/Controls/ItemList.cs

@@ -385,16 +385,16 @@ namespace Robust.Client.UserInterface.Controls
             var offsetY = (int) (box.Height - font.GetHeight(UIScale)) / 2;
             var baseLine = new Vector2i(0, offsetY + font.GetAscent(UIScale)) + box.TopLeft;
 
-            foreach (var chr in text)
+            foreach (var rune in text.EnumerateRunes())
             {
-                if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                 {
                     continue;
                 }
 
                 if (!(baseLine.X < box.Left || baseLine.X + metrics.Advance > box.Right))
                 {
-                    font.DrawChar(handle, chr, baseLine, UIScale, color);
+                    font.DrawChar(handle, rune, baseLine, UIScale, color);
                 }
 
                 baseLine += (metrics.Advance, 0);

Robust.Client/UserInterface/Controls/Label.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Text;
 using Robust.Client.Graphics;
 using Robust.Shared.Animations;
 using Robust.Shared.Maths;
@@ -180,15 +181,15 @@ namespace Robust.Client.UserInterface.Controls
 
             var baseLine = CalcBaseline();
 
-            foreach (var chr in _text)
+            foreach (var rune in _text.EnumerateRunes())
             {
-                if (chr == '\n')
+                if (rune == new Rune('\n'))
                 {
                     newlines += 1;
                     baseLine = CalcBaseline();
                 }
 
-                var advance = font.DrawChar(handle, chr, baseLine, UIScale, actualFontColor);
+                var advance = font.DrawChar(handle, rune, baseLine, UIScale, actualFontColor);
                 baseLine += (advance, 0);
             }
         }
@@ -252,16 +253,16 @@ namespace Robust.Client.UserInterface.Controls
 
             var font = ActualFont;
             var height = font.GetHeight(UIScale);
-            foreach (var chr in _text)
+            foreach (var rune in _text.EnumerateRunes())
             {
-                if (chr == '\n')
+                if (rune == new Rune('\n'))
                 {
                     _cachedTextWidths.Add(0);
                     height += font.GetLineHeight(UIScale);
                 }
                 else
                 {
-                    var metrics = font.GetCharMetrics(chr, UIScale);
+                    var metrics = font.GetCharMetrics(rune, UIScale);
                     if (metrics == null)
                     {
                         continue;

Robust.Client/UserInterface/Controls/LineEdit.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Text;
 using JetBrains.Annotations;
 using Robust.Client.Graphics;
 using Robust.Shared.Input;
@@ -23,6 +24,7 @@ namespace Robust.Client.UserInterface.Controls
         public const string StyleClassLineEditNotEditable = "notEditable";
         public const string StylePseudoClassPlaceholder = "placeholder";
 
+        // It is assumed that these two positions are NEVER inside a surrogate pair in the text buffer.
         private int _cursorPosition;
         private int _selectionStart;
         private string _text = "";
@@ -126,7 +128,11 @@ namespace Robust.Client.UserInterface.Controls
             get => _cursorPosition;
             set
             {
-                _cursorPosition = MathHelper.Clamp(value, 0, _text.Length);
+                var clamped = MathHelper.Clamp(value, 0, _text.Length);
+                if (_text.Length != 0 && _text.Length != clamped && !Rune.TryGetRuneAt(_text, clamped, out _))
+                    throw new ArgumentException("Cannot set cursor inside surrogate pair.");
+
+                _cursorPosition = clamped;
                 _selectionStart = _cursorPosition;
             }
         }
@@ -134,7 +140,14 @@ namespace Robust.Client.UserInterface.Controls
         public int SelectionStart
         {
             get => _selectionStart;
-            set => _selectionStart = MathHelper.Clamp(value, 0, _text.Length);
+            set
+            {
+                var clamped = MathHelper.Clamp(value, 0, _text.Length);
+                if (_text.Length != 0 && _text.Length != clamped && !Rune.TryGetRuneAt(_text, clamped, out _))
+                    throw new ArgumentException("Cannot set cursor inside surrogate pair.");
+
+                _selectionStart = clamped;
+            }
         }
 
         public int SelectionLower => Math.Min(_selectionStart, _cursorPosition);
@@ -275,7 +288,7 @@ namespace Robust.Client.UserInterface.Controls
                 return;
             }
 
-            InsertAtCursor(((char) args.CodePoint).ToString());
+            InsertAtCursor(args.AsRune.ToString());
         }
 
         protected internal override void KeyBindDown(GUIBoundKeyEventArgs args)
@@ -302,8 +315,16 @@ namespace Robust.Client.UserInterface.Controls
                         }
                         else if (_cursorPosition != 0)
                         {
-                            _text = _text.Remove(_cursorPosition - 1, 1);
-                            _cursorPosition -= 1;
+                            var remPos = _cursorPosition - 1;
+                            var remAmt = 1;
+                            // If this is a low surrogate remove two chars to remove the whole pair.
+                            if (char.IsLowSurrogate(_text[remPos]))
+                            {
+                                remPos -= 1;
+                                remAmt = 2;
+                            }
+                            _text = _text.Remove(remPos, remAmt);
+                            _cursorPosition -= remAmt;
                             changed = true;
                         }
 
@@ -330,7 +351,10 @@ namespace Robust.Client.UserInterface.Controls
                         }
                         else if (_cursorPosition < _text.Length)
                         {
-                            _text = _text.Remove(_cursorPosition, 1);
+                            var remAmt = 1;
+                            if (char.IsHighSurrogate(_text[_cursorPosition]))
+                                remAmt = 2;
+                            _text = _text.Remove(_cursorPosition, remAmt);
                             changed = true;
                         }
 
@@ -352,10 +376,7 @@ namespace Robust.Client.UserInterface.Controls
                     }
                     else
                     {
-                        if (_cursorPosition != 0)
-                        {
-                            _cursorPosition -= 1;
-                        }
+                        ShiftCursorLeft();
 
                         _selectionStart = _cursorPosition;
                     }
@@ -370,10 +391,7 @@ namespace Robust.Client.UserInterface.Controls
                     }
                     else
                     {
-                        if (_cursorPosition != _text.Length)
-                        {
-                            _cursorPosition += 1;
-                        }
+                        ShiftCursorRight();
 
                         _selectionStart = _cursorPosition;
                     }
@@ -404,19 +422,13 @@ namespace Robust.Client.UserInterface.Controls
                 }
                 else if (args.Function == EngineKeyFunctions.TextCursorSelectLeft)
                 {
-                    if (_cursorPosition != 0)
-                    {
-                        _cursorPosition -= 1;
-                    }
+                    ShiftCursorLeft();
 
                     args.Handle();
                 }
                 else if (args.Function == EngineKeyFunctions.TextCursorSelectRight)
                 {
-                    if (_cursorPosition != _text.Length)
-                    {
-                        _cursorPosition += 1;
-                    }
+                    ShiftCursorRight();
 
                     args.Handle();
                 }
@@ -525,6 +537,32 @@ namespace Robust.Client.UserInterface.Controls
 
             // Reset this so the cursor is always visible immediately after a keybind is pressed.
             _resetCursorBlink();
+
+            void ShiftCursorLeft()
+            {
+                if (_cursorPosition == 0)
+                    return;
+
+                _cursorPosition -= 1;
+
+                if (char.IsLowSurrogate(_text[_cursorPosition]))
+                    _cursorPosition -= 1;
+            }
+
+            void ShiftCursorRight()
+            {
+                if (_cursorPosition == _text.Length)
+                    return;
+
+                _cursorPosition += 1;
+
+                // Before you confuse yourself on "shouldn't this be high surrogate since shifting left checks low"
+                // (Because yes, I did myself too a week after writing it)
+                // char.IsLowSurrogate(_text[_cursorPosition]) means "is the cursor between a surrogate pair"
+                // because we ALREADY moved.
+                if (_cursorPosition != _text.Length && char.IsLowSurrogate(_text[_cursorPosition]))
+                    _cursorPosition += 1;
+            }
         }
 
         protected internal override void KeyBindUp(GUIBoundKeyEventArgs args)
@@ -555,11 +593,11 @@ namespace Robust.Client.UserInterface.Controls
             var index = 0;
             var chrPosX = contentBox.Left - _drawOffset;
             var lastChrPostX = contentBox.Left - _drawOffset;
-            foreach (var chr in _text)
+            foreach (var rune in _text.EnumerateRunes())
             {
-                if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                 {
-                    index += 1;
+                    index += rune.Utf16SequenceLength;
                     continue;
                 }
 
@@ -570,7 +608,7 @@ namespace Robust.Client.UserInterface.Controls
 
                 lastChrPostX = chrPosX;
                 chrPosX += metrics.Advance;
-                index += 1;
+                index += rune.Utf16SequenceLength;
 
                 if (chrPosX > contentBox.Right)
                 {
@@ -586,6 +624,9 @@ namespace Robust.Client.UserInterface.Controls
             if (index > 0 && distanceRight > distanceLeft)
             {
                 index -= 1;
+
+                if (char.IsLowSurrogate(_text[index]))
+                    index -= 1;
             }
 
             return index;
@@ -652,60 +693,87 @@ namespace Robust.Client.UserInterface.Controls
         }
 
         // Approach for NextWordPosition and PrevWordPosition taken from Avalonia.
-        private int NextWordPosition(string str, int cursor)
+        internal static int NextWordPosition(string str, int cursor)
         {
             if (cursor >= str.Length)
             {
                 return str.Length;
             }
 
-            var charClass = GetCharClass(str[cursor]);
+            var charClass = GetCharClass(Rune.GetRuneAt(str, cursor));
 
             var i = cursor;
-            for (; i < str.Length && GetCharClass(str[i]) == charClass; i++)
-            {
-            }
 
-            for (; i < str.Length && GetCharClass(str[i]) == CharClass.Whitespace; i++)
-            {
-            }
+            IterForward(charClass);
+            IterForward(CharClass.Whitespace);
 
             return i;
+
+            void IterForward(CharClass cClass)
+            {
+                while (i < str.Length)
+                {
+                    var rune = Rune.GetRuneAt(str, i);
+
+                    if (GetCharClass(rune) != cClass)
+                        break;
+
+                    i += rune.Utf16SequenceLength;
+                }
+            }
         }
 
-        private int PrevWordPosition(string str, int cursor)
+        internal static int PrevWordPosition(string str, int cursor)
         {
             if (cursor == 0)
             {
                 return 0;
             }
 
-            var charClass = GetCharClass(str[cursor - 1]);
+            var startRune = GetRuneBackwards(str, cursor - 1);
+            var charClass = GetCharClass(startRune);
 
             var i = cursor;
-            for (; i > 0 && GetCharClass(str[i - 1]) == charClass; i--)
-            {
-            }
+            IterBackward();
 
             if (charClass == CharClass.Whitespace)
             {
-                charClass = GetCharClass(str[i - 1]);
-                for (; i > 0 && GetCharClass(str[i - 1]) == charClass; i--)
-                {
-                }
+                if (!Rune.TryGetRuneAt(str, i - 1, out var midRune))
+                    midRune = Rune.GetRuneAt(str, i - 2);
+                charClass = GetCharClass(midRune);
+
+                IterBackward();
             }
 
             return i;
+
+            void IterBackward()
+            {
+                while (i > 0)
+                {
+                    var rune = GetRuneBackwards(str, i - 1);
+
+                    if (GetCharClass(rune) != charClass)
+                        break;
+
+                    i -= rune.Utf16SequenceLength;
+                }
+            }
+
+            static Rune GetRuneBackwards(string str, int i)
+            {
+                return Rune.TryGetRuneAt(str, i, out var rune) ? rune : Rune.GetRuneAt(str, i - 1);
+            }
         }
 
-        private CharClass GetCharClass(char chr)
+        internal static CharClass GetCharClass(Rune rune)
         {
-            if (char.IsWhiteSpace(chr))
+            if (Rune.IsWhiteSpace(rune))
             {
                 return CharClass.Whitespace;
             }
 
-            if (char.IsLetterOrDigit(chr))
+            if (Rune.IsLetterOrDigit(rune))
             {
                 return CharClass.AlphaNumeric;
             }
@@ -713,7 +781,7 @@ namespace Robust.Client.UserInterface.Controls
             return CharClass.Other;
         }
 
-        private enum CharClass : byte
+        internal enum CharClass : byte
         {
             Other,
             AlphaNumeric,
@@ -767,7 +835,7 @@ namespace Robust.Client.UserInterface.Controls
                 var posX = 0;
                 var actualCursorPosition = 0;
                 var actualSelectionStartPosition = 0;
-                foreach (var chr in renderedText)
+                foreach (var chr in renderedText.EnumerateRunes())
                 {
                     if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
                     {
@@ -776,7 +844,7 @@ namespace Robust.Client.UserInterface.Controls
                     }
 
                     posX += metrics.Advance;
-                    count += 1;
+                    count += chr.Utf16SequenceLength;
 
                     if (count == _master._cursorPosition)
                     {
@@ -816,9 +884,9 @@ namespace Robust.Client.UserInterface.Controls
                 var baseLine = (-drawOffset, offsetY + font.GetAscent(UIScale)) +
                                contentBox.TopLeft;
 
-                foreach (var chr in renderedText)
+                foreach (var rune in renderedText.EnumerateRunes())
                 {
-                    if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                     {
                         continue;
                     }
@@ -832,7 +900,7 @@ namespace Robust.Client.UserInterface.Controls
                     // Make sure we're not off the left edge of the box.
                     if (baseLine.X + metrics.BearingX + metrics.Width >= contentBox.Left)
                     {
-                        font.DrawChar(handle, chr, baseLine, UIScale, renderedTextColor);
+                        font.DrawChar(handle, rune, baseLine, UIScale, renderedTextColor);
                     }
 
                     baseLine += (metrics.Advance, 0);

Robust.Client/UserInterface/Controls/TabContainer.cs

@@ -163,9 +163,9 @@ namespace Robust.Client.UserInterface.Controls
 
                 var titleLength = 0;
                 // Get string length.
-                foreach (var chr in title)
+                foreach (var rune in title.EnumerateRunes())
                 {
-                    if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                     {
                         continue;
                     }
@@ -196,14 +196,14 @@ namespace Robust.Client.UserInterface.Controls
 
                 var baseLine = new Vector2(0, font.GetAscent(UIScale)) + contentBox.TopLeft;
 
-                foreach (var chr in title)
+                foreach (var rune in title.EnumerateRunes())
                 {
-                    if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                     {
                         continue;
                     }
 
-                    font.DrawChar(handle, chr, baseLine, UIScale, active ? fontColorActive : fontColorInactive);
+                    font.DrawChar(handle, rune, baseLine, UIScale, active ? fontColorActive : fontColorInactive);
                     baseLine += new Vector2(metrics.Advance, 0);
                 }
 
@@ -295,9 +295,9 @@ namespace Robust.Client.UserInterface.Controls
 
                 var titleLength = 0;
                 // Get string length.
-                foreach (var chr in title)
+                foreach (var rune in title.EnumerateRunes())
                 {
-                    if (!font.TryGetCharMetrics(chr, UIScale, out var metrics))
+                    if (!font.TryGetCharMetrics(rune, UIScale, out var metrics))
                     {
                         continue;
                     }

Robust.Client/UserInterface/Controls/Tree.cs

@@ -219,9 +219,9 @@ namespace Robust.Client.UserInterface.Controls
             {
                 var offset = itemSelected.GetContentOffset(Vector2.Zero);
                 var baseLine = offset + (hOffset, vOffset + font.GetAscent(UIScale));
-                foreach (var chr in item.Text)
+                foreach (var rune in item.Text.EnumerateRunes())
                 {
-                    baseLine += (font.DrawChar(handle, chr, baseLine, UIScale, Color.White), 0);
+                    baseLine += (font.DrawChar(handle, rune, baseLine, UIScale, Color.White), 0);
                 }
             }
 

Robust.Client/UserInterface/CustomControls/DebugConsole.cs

@@ -2,12 +2,14 @@ using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
-using Newtonsoft.Json;
+using System.Text.Json;
+using System.Threading.Tasks;
 using Robust.Client.Console;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
 using Robust.Shared.ContentPack;
 using Robust.Shared.Input;
+using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
@@ -301,43 +303,95 @@ namespace Robust.Client.UserInterface.CustomControls
 
         private async void _loadHistoryFromDisk()
         {
-            CommandBar.ClearHistory();
-            Stream stream;
-            try
+            var sawmill = Logger.GetSawmill("dbgconsole");
+            var data = await Task.Run(async () =>
             {
-                stream = _resourceManager.UserData.OpenRead(HistoryPath);
-            }
-            catch (FileNotFoundException)
-            {
-                // Nada, nothing to load in that case.
-                return;
-            }
-
-            try
-            {
-                using (var reader = new StreamReader(stream, EncodingHelpers.UTF8))
+                Stream? stream = null;
+                for (var i = 0; i < 3; i++)
                 {
-                    var data = JsonConvert.DeserializeObject<List<string>>(await reader.ReadToEndAsync());
-                    CommandBar.ClearHistory();
-                    CommandBar.History.AddRange(data);
-                    CommandBar.HistoryIndex = CommandBar.History.Count;
+                    try
+                    {
+                        stream = _resourceManager.UserData.OpenRead(HistoryPath);
+                        break;
+                    }
+                    catch (FileNotFoundException)
+                    {
+                        // Nada, nothing to load in that case.
+                        return null;
+                    }
+                    catch (IOException)
+                    {
+                        // File locked probably??
+                        await Task.Delay(10);
+                    }
                 }
-            }
-            finally
-            {
-                stream?.Dispose();
-            }
+
+                if (stream == null)
+                {
+                    sawmill.Warning("Failed to load debug console history!");
+                    return null;
+                }
+
+                try
+                {
+                    return await JsonSerializer.DeserializeAsync<string[]>(stream);
+                }
+                catch (Exception e)
+                {
+                    sawmill.Warning("Failed to load debug console history due to exception!\n{e}");
+                    return null;
+                }
+                finally
+                {
+                    // ReSharper disable once MethodHasAsyncOverload
+                    stream.Dispose();
+                }
+            });
+
+            if (data == null)
+                return;
+
+            CommandBar.ClearHistory();
+            CommandBar.History.AddRange(data);
+            CommandBar.HistoryIndex = CommandBar.History.Count;
         }
 
-        private void _flushHistoryToDisk()
+        private async void _flushHistoryToDisk()
         {
-            using (var stream = _resourceManager.UserData.Create(HistoryPath))
-            using (var writer = new StreamWriter(stream, EncodingHelpers.UTF8))
+            CommandBar.HistoryIndex = CommandBar.History.Count;
+
+            var sawmill = Logger.GetSawmill("dbgconsole");
+            var newHistory = JsonSerializer.Serialize(CommandBar.History);
+
+            await Task.Run(async () =>
             {
-                var data = JsonConvert.SerializeObject(CommandBar.History);
-                CommandBar.HistoryIndex = CommandBar.History.Count;
-                writer.Write(data);
-            }
+                Stream? stream = null;
+
+                for (var i = 0; i < 3; i++)
+                {
+                    try
+                    {
+                        stream = _resourceManager.UserData.Create(HistoryPath);
+                        break;
+                    }
+                    catch (IOException)
+                    {
+                        // Probably locking.
+                        await Task.Delay(10);
+                    }
+                }
+
+                if (stream == null)
+                {
+                    sawmill.Warning("Failed to save debug console history!");
+                    return;
+                }
+
+                // ReSharper disable once UseAwaitUsing
+                using var writer = new StreamWriter(stream, EncodingHelpers.UTF8);
+                // ReSharper disable once MethodHasAsyncOverload
+                writer.Write(newHistory);
+            });
         }
     }
 }

Robust.Client/UserInterface/CustomControls/DebugNetBandwidthPanel.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
@@ -45,9 +45,9 @@ namespace Robust.Client.UserInterface.CustomControls
             Visible = false;
         }
 
-        protected override void Update(FrameEventArgs args)
+        protected override void FrameUpdate(FrameEventArgs args)
         {
-            base.Update(args);
+            base.FrameUpdate(args);
 
             if ((_gameTiming.RealTime - _lastUpdate).Seconds < 1 || !VisibleInTree)
             {

Robust.Client/UserInterface/CustomControls/DebugNetPanel.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
 using Robust.Shared.Maths;
@@ -51,9 +51,9 @@ namespace Robust.Client.UserInterface.CustomControls
             MouseFilter = contents.MouseFilter = MouseFilterMode.Ignore;
         }
 
-        protected override void Update(FrameEventArgs args)
+        protected override void FrameUpdate(FrameEventArgs args)
         {
-            base.Update(args);
+            base.FrameUpdate(args);
 
             if ((GameTiming.RealTime - LastUpdate).Seconds < 1 || !VisibleInTree)
             {

Robust.Client/UserInterface/CustomControls/DebugTimePanel.cs

@@ -1,4 +1,4 @@
-using Robust.Client.GameStates;
+using Robust.Client.GameStates;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
 using Robust.Shared.Maths;
@@ -36,9 +36,9 @@ namespace Robust.Client.UserInterface.CustomControls
             HorizontalAlignment = HAlignment.Left;
         }
 
-        protected override void Update(FrameEventArgs args)
+        protected override void FrameUpdate(FrameEventArgs args)
         {
-            base.Update(args);
+            base.FrameUpdate(args);
 
             if (!VisibleInTree)
             {

Robust.Client/UserInterface/CustomControls/EntitySpawnWindow.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
@@ -67,6 +67,7 @@ namespace Robust.Client.UserInterface.CustomControls
 
             Title = Loc.GetString("Entity Spawn Panel");
 
+
             SetSize = (250, 300);
             MinSize = (250, 200);
 

Robust.Client/UserInterface/CustomControls/FpsCounter.cs

@@ -1,4 +1,4 @@
-using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface.Controls;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
 
@@ -17,7 +17,7 @@ namespace Robust.Client.UserInterface.CustomControls
             ShadowOffsetYOverride = 1;
         }
 
-        protected override void Update(FrameEventArgs args)
+        protected override void FrameUpdate(FrameEventArgs args)
         {
             if (!VisibleInTree)
             {

Robust.Client/UserInterface/CustomControls/FrameGraph.cs

@@ -1,4 +1,6 @@
-using Robust.Client.Graphics;
+using System;
+using System.Collections;
+using Robust.Client.Graphics;
 using Robust.Shared.Maths;
 using Robust.Shared.Timing;
 
@@ -31,9 +33,11 @@ namespace Robust.Client.UserInterface.CustomControls
 
         // We keep track of frame times in a ring buffer.
         private readonly float[] _frameTimes = new float[TrackedFrames];
+        private readonly BitArray _gcMarkers = new(TrackedFrames);
 
         // Position of the last frame in the ring buffer.
         private int _frameIndex;
+        private int _lastGCCount;
 
         public FrameGraph(IGameTiming gameTiming)
         {
@@ -49,14 +53,21 @@ namespace Robust.Client.UserInterface.CustomControls
 
         protected override void FrameUpdate(FrameEventArgs args)
         {
+            var gcCount = GC.CollectionCount(0);
+
             _frameTimes[_frameIndex] = (float)_gameTiming.RealFrameTime.TotalSeconds;
+            _gcMarkers[_frameIndex] = gcCount > _lastGCCount;
+
             _frameIndex = (_frameIndex + 1) % TrackedFrames;
+            _lastGCCount = gcCount;
         }
 
         protected internal override void Draw(DrawingHandleScreen handle)
         {
             base.Draw(handle);
 
+            Span<Vector2> triangle = stackalloc Vector2[3];
+
             float maxHeight = 0;
             for (var i = 0; i < _frameTimes.Length; i++)
             {
@@ -88,6 +99,16 @@ namespace Robust.Client.UserInterface.CustomControls
                     color = Color.Lime;
                 }
                 handle.DrawRect(rect, color);
+
+                var gc = _gcMarkers[currentFrameIndex];
+                if (gc)
+                {
+                    triangle[0] = (rect.Left, 0);
+                    triangle[1] = (rect.Right, 0);
+                    triangle[2] = (rect.Center.X, 5);
+
+                    handle.DrawPrimitives(DrawPrimitiveTopology.TriangleList, triangle, Color.LightBlue);
+                }
             }
         }
     }

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

@@ -91,7 +91,7 @@ namespace Robust.Client.UserInterface.CustomControls
 
         // Prevent window headers from getting off screen due to game window resizes.
 
-        protected override void Update(FrameEventArgs args)
+        protected override void FrameUpdate(FrameEventArgs args)
         {
             var (spaceX, spaceY) = Parent!.Size;
             if (Position.Y > spaceY)

Robust.Client/UserInterface/IUserInterfaceManagerInternal.cs

@@ -17,8 +17,6 @@ namespace Robust.Client.UserInterface
         void Initialize();
         void InitializeTesting();
 
-        void Update(FrameEventArgs args);
-
         void FrameUpdate(FrameEventArgs args);
 
         /// <returns>True if a UI control was hit and the key event should not pass through past UI.</returns>

Robust.Client/UserInterface/RichTextEntry.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Text;
 using JetBrains.Annotations;
 using Robust.Client.Graphics;
 using Robust.Client.UserInterface.Controls;
@@ -65,7 +66,7 @@ namespace Robust.Client.UserInterface
             var wordSizePixels = 0;
             // The horizontal position of the text cursor.
             var posX = 0;
-            var lastChar = 'A';
+            var lastRune = new Rune('A');
             // If a word is larger than maxSizeX, we split it.
             // We need to keep track of some data to split it into two words.
             (int breakIndex, int wordSizePixels)? forceSplitData = null;
@@ -83,14 +84,14 @@ namespace Robust.Client.UserInterface
 
                 var text = tagText.Text;
                 // And go over every character.
-                for (var i = 0; i < text.Length; i++, breakIndexCounter++)
+                foreach (var rune in text.EnumerateRunes())
                 {
-                    var chr = text[i];
+                    breakIndexCounter += 1;
 
-                    if (IsWordBoundary(lastChar, chr) || chr == '\n')
+                    if (IsWordBoundary(lastRune, rune) || rune == new Rune('\n'))
                     {
                         // Word boundary means we know where the word ends.
-                        if (posX > maxSizeX && lastChar != ' ')
+                        if (posX > maxSizeX && lastRune != new Rune(' '))
                         {
                             DebugTools.Assert(wordStartBreakIndex.HasValue,
                                 "wordStartBreakIndex can only be null if the word begins at a new line, in which case this branch shouldn't be reached as the word would be split due to being longer than a single line.");
@@ -109,22 +110,22 @@ namespace Robust.Client.UserInterface
                         forceSplitData = null;
 
                         // Just manually handle newlines.
-                        if (chr == '\n')
+                        if (rune == new Rune('\n'))
                         {
                             LineBreaks.Add(breakIndexCounter);
                             Height += font.GetLineHeight(uiScale);
                             maxUsedWidth = Math.Max(maxUsedWidth, posX);
                             posX = 0;
-                            lastChar = chr;
+                            lastRune = rune;
                             wordStartBreakIndex = null;
                             continue;
                         }
                     }
 
                     // Uh just skip unknown characters I guess.
-                    if (!font.TryGetCharMetrics(chr, uiScale, out var metrics))
+                    if (!font.TryGetCharMetrics(rune, uiScale, out var metrics))
                     {
-                        lastChar = chr;
+                        lastRune = rune;
                         continue;
                     }
 
@@ -165,7 +166,7 @@ namespace Robust.Client.UserInterface
                         }
                     }
 
-                    lastChar = chr;
+                    lastRune = rune;
                 }
             }
 
@@ -185,7 +186,7 @@ namespace Robust.Client.UserInterface
                     Logger.Error("wordStartBreakIndex: null (duh)");
                     Logger.Error($"wordSizePixels: {wordSizePixels}");
                     Logger.Error($"posX: {posX}");
-                    Logger.Error($"lastChar: {lastChar}");
+                    Logger.Error($"lastChar: {lastRune}");
                     Logger.Error($"forceSplitData: {forceSplitData}");
                     Logger.Error($"LineBreaks: {string.Join(", ", LineBreaks)}");
 
@@ -247,9 +248,10 @@ namespace Robust.Client.UserInterface
                     case FormattedMessage.TagText tagText:
                     {
                         var text = tagText.Text;
-                        for (var i = 0; i < text.Length; i++, globalBreakCounter++)
+                        foreach (var rune in text.EnumerateRunes())
                         {
-                            var chr = text[i];
+                            globalBreakCounter += 1;
+
                             if (lineBreakIndex < LineBreaks.Count &&
                                 LineBreaks[lineBreakIndex] == globalBreakCounter)
                             {
@@ -257,7 +259,7 @@ namespace Robust.Client.UserInterface
                                 lineBreakIndex += 1;
                             }
 
-                            var advance = font.DrawChar(handle, chr, baseLine, uiScale, currentColorTag.Color);
+                            var advance = font.DrawChar(handle, rune, baseLine, uiScale, currentColorTag.Color);
                             baseLine += new Vector2(advance, 0);
                         }
 
@@ -268,9 +270,9 @@ namespace Robust.Client.UserInterface
         }
 
         [Pure]
-        private static bool IsWordBoundary(char a, char b)
+        private static bool IsWordBoundary(Rune a, Rune b)
         {
-            return a == ' ' || b == ' ' || a == '-' || b == '-';
+            return a == new Rune(' ') || b == new Rune(' ') || a == new Rune('-') || b == new Rune('-');
         }
     }
 }

Robust.Client/UserInterface/UserInterfaceManager.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Robust.Client.Console;
 using Robust.Client.Graphics;
@@ -133,6 +133,7 @@ namespace Robust.Client.UserInterface
             QueueMeasureUpdate(RootControl);
 
             _displayManager.OnWindowResized += args => _updateRootSize();
+            _displayManager.OnWindowScaleChanged += UpdateUIScale;
 
             StateRoot = new LayoutContainer
             {
@@ -174,15 +175,9 @@ namespace Robust.Client.UserInterface
             _initializeCommon();
         }
 
-        public void Update(FrameEventArgs args)
-        {
-            RootControl.DoUpdate(args);
-        }
-
+        /// <inheritdoc />
         public void FrameUpdate(FrameEventArgs args)
         {
-            RootControl.DoFrameUpdate(args);
-
             // Process queued style & layout updates.
             while (_styleUpdateQueue.Count != 0)
             {
@@ -220,6 +215,8 @@ namespace Robust.Client.UserInterface
                 RunArrange(control);
             }
 
+            RootControl.DoFrameUpdate(args);
+
             // count down tooltip delay if we're not showing one yet and
             // are hovering the mouse over a control without moving it
             if (_tooltipDelay != null && !showingTooltip)
@@ -833,7 +830,13 @@ namespace Robust.Client.UserInterface
 
         private void _uiScaleChanged(float newValue)
         {
-            UIScale = newValue == 0f ? DefaultUIScale : newValue;
+            UpdateUIScale();
+        }
+
+        private void UpdateUIScale()
+        {
+            var newVal = _configurationManager.GetCVar(CVars.DisplayUIScale);
+            UIScale = newVal == 0f ? DefaultUIScale : newVal;
 
             if (RootControl == null)
             {

Robust.Client/Utility/ImageSharpExt.cs

@@ -42,19 +42,20 @@ namespace Robust.Client.Utility
         {
             var dstSpan = destination.GetPixelSpan();
             var dstWidth = destination.Width;
+            var srcHeight = sourceRect.Height;
+            var srcWidth = sourceRect.Width;
 
             var (ox, oy) = destinationOffset;
 
-            for (var y = 0; y < sourceRect.Height; y++)
+            for (var y = 0; y < srcHeight; y++)
             {
                 var sourceRowOffset = sourceWidth * (y + sourceRect.Top) + sourceRect.Left;
                 var destRowOffset = dstWidth * (y + oy) + ox;
 
-                for (var x = 0; x < sourceRect.Width; x++)
-                {
-                    var pixel = source[x + sourceRowOffset];
-                    dstSpan[x + destRowOffset] = pixel;
-                }
+                var srcRow = source[sourceRowOffset..(sourceRowOffset + srcWidth)];
+                var dstRow = dstSpan[destRowOffset..(destRowOffset + srcWidth)];
+
+                srcRow.CopyTo(dstRow);
             }
         }
 

Robust.Client/Utility/SpriteSpecifierExt.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
@@ -41,6 +41,40 @@ namespace Robust.Client.Utility
             return specifier.RsiStateLike().Default;
         }
 
+        public static float[] FrameDelays(this SpriteSpecifier specifier) {
+            var resc = IoCManager.Resolve<IResourceCache>();
+            switch (specifier) {
+                case SpriteSpecifier.Rsi rsi:
+                    if (resc.TryGetResource<RSIResource>(SpriteComponent.TextureRoot / rsi.RsiPath, out var theRsi)) {
+                        if (theRsi.RSI.TryGetState(rsi.RsiState, out var state)) {
+                            return state.Delays;
+                        }
+                    }
+                    Logger.Error("Failed to load RSI {0}", rsi.RsiPath);
+                    return new float[0];
+
+                default:
+                    throw new NotImplementedException();
+            }
+        }
+
+        public static Texture[] FrameArr(this SpriteSpecifier specifier) {
+            var resc = IoCManager.Resolve<IResourceCache>();
+            switch (specifier) {
+                case SpriteSpecifier.Rsi rsi:
+                    if (resc.TryGetResource<RSIResource>(SpriteComponent.TextureRoot / rsi.RsiPath, out var theRsi)) {
+                        if (theRsi.RSI.TryGetState(rsi.RsiState, out var state)) {
+                            return state.Icons[0];
+                        }
+                    }
+                    Logger.Error("Failed to load RSI {0}", rsi.RsiPath);
+                    return new Texture[0];
+
+                default:
+                    throw new NotImplementedException();
+            }
+        }
+
         public static IDirectionalTextureProvider DirFrame0(this SpriteSpecifier specifier)
         {
             return specifier.RsiStateLike();

Robust.Server/BaseServer.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.IO;
+using System.Runtime;
 using System.Runtime.InteropServices;
 using System.Threading;
 using Prometheus;
@@ -93,8 +94,8 @@ namespace Robust.Server
         private IGameLoop _mainLoop = default!;
 
         private TimeSpan _lastTitleUpdate;
-        private int _lastReceivedBytes;
-        private int _lastSentBytes;
+        private long _lastReceivedBytes;
+        private long _lastSentBytes;
 
         private string? _shutdownReason;
 
@@ -141,6 +142,10 @@ namespace Robust.Server
         /// <inheritdoc />
         public bool Start(Func<ILogHandler>? logHandlerFactory = null)
         {
+            var profilePath = Path.Join(Environment.CurrentDirectory, "AAAAAAAA");
+            ProfileOptimization.SetProfileRoot(profilePath);
+            ProfileOptimization.StartProfile("AAAAAAAAAA");
+
             _config.Initialize(true);
 
             if (LoadConfigAndUserData)
@@ -178,6 +183,8 @@ namespace Robust.Server
                 _config.OverrideConVars(_commandLineArgs.CVars);
             }
 
+            ProfileOptSetup.Setup(_config);
+
             //Sets up Logging
             _logHandlerFactory = logHandlerFactory;
 
@@ -327,6 +334,8 @@ namespace Robust.Server
                 WindowsTickPeriod.TimeBeginPeriod((uint) _config.GetCVar(CVars.SysWinTickPeriod));
             }
 
+            GC.Collect();
+
             return false;
         }
 
@@ -564,7 +573,7 @@ namespace Robust.Server
             }
 
             // Pass Histogram into the IEntityManager.Update so it can do more granular measuring.
-            _entities.Update(frameEventArgs.DeltaSeconds, TickUsage);
+            _entities.TickUpdate(frameEventArgs.DeltaSeconds, TickUsage);
 
             using (TickUsage.WithLabels("PostEngine").NewTimer())
             {

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

@@ -51,7 +51,7 @@ namespace Robust.Server.GameObjects
         }
     }
 
-    public class PlayerAttachSystemMessage : EntitySystemMessage
+    public class PlayerAttachSystemMessage : EntityEventArgs
     {
         public PlayerAttachSystemMessage(IEntity entity, IPlayerSession newPlayer)
         {
@@ -63,7 +63,7 @@ namespace Robust.Server.GameObjects
         public IPlayerSession NewPlayer { get; }
     }
 
-    public class PlayerDetachedSystemMessage : EntitySystemMessage
+    public class PlayerDetachedSystemMessage : EntityEventArgs
     {
         public PlayerDetachedSystemMessage(IEntity entity)
         {

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

@@ -16,6 +16,7 @@ namespace Robust.Server.GameObjects
         private Vector2 _zoom = Vector2.One/2f;
         private Vector2 _offset;
         private Angle _rotation;
+        private uint _visibilityMask;
 
         public override bool DrawFov
         {
@@ -69,9 +70,22 @@ namespace Robust.Server.GameObjects
             }
         }
 
+        public override uint VisibilityMask
+        {
+            get => _visibilityMask;
+            set
+            {
+                if(_visibilityMask == value)
+                    return;
+
+                _visibilityMask = value;
+                Dirty();
+            }
+        }
+
         public override ComponentState GetComponentState(ICommonSession player)
         {
-            return new EyeComponentState(DrawFov, Zoom, Offset, Rotation);
+            return new EyeComponentState(DrawFov, Zoom, Offset, Rotation, VisibilityMask);
         }
     }
 }

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

@@ -8,6 +8,7 @@ using Robust.Shared.Prototypes;
 using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 
@@ -24,7 +25,7 @@ namespace Robust.Server.GameObjects
         [DataField("visible")]
         private bool _visible = true;
 
-        [DataFieldWithConstant("drawdepth", typeof(DrawDepthTag))]
+        [DataField("drawdepth", customTypeSerializer: typeof(ConstantSerializer<DrawDepthTag>))]
         private int _drawDepth = DrawDepthTag.Default;
 
         [DataField("scale")]
@@ -54,17 +55,19 @@ namespace Robust.Server.GameObjects
             get => _drawDepth;
             set
             {
+                if (_drawDepth == value) return;
                 _drawDepth = value;
                 Dirty();
             }
         }
 
         [ViewVariables(VVAccess.ReadWrite)]
-        public bool Visible
+        public override bool Visible
         {
             get => _visible;
             set
             {
+                if (_visible == value) return;
                 _visible = value;
                 Dirty();
             }

Robust.Server/GameObjects/EntitySystemMessages/EntityTileMessage.cs

@@ -12,7 +12,7 @@ namespace Robust.Server.GameObjects
     /// <remarks>
     ///    List is empty if it's no longer intersecting any.
     /// </remarks>
-    public sealed class TileLookupUpdateMessage : EntitySystemMessage
+    public sealed class TileLookupUpdateMessage : EntityEventArgs
     {
         public Dictionary<GridId, List<Vector2i>>? NewIndices { get; }
 

Robust.Server/GameObjects/EntitySystems/AudioSystem.cs

@@ -1,20 +1,17 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using Robust.Server.Player;
+using JetBrains.Annotations;
 using Robust.Shared.Audio;
 using Robust.Shared.GameObjects;
-using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Player;
 using Robust.Shared.Players;
 
 namespace Robust.Server.GameObjects
 {
+    [UsedImplicitly]
     public class AudioSystem : EntitySystem, IAudioSystem
     {
-        [Dependency] private readonly IPlayerManager _playerManager = default!;
-
         private const int AudioDistanceRange = 25;
 
         private uint _streamIndex;
@@ -66,147 +63,6 @@ namespace Robust.Server.GameObjects
             return unchecked(_streamIndex++);
         }
 
-        /// <summary>
-        ///     Play an audio file globally, without position.
-        /// </summary>
-        /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
-        /// <param name="audioParams"></param>
-        /// <param name="predicate">The predicate that will be used to send the audio to players, or null to send to everyone.</param>
-        /// <param name="excludedSession">Session that won't receive the audio message.</param>
-        /// <param name="recipients"></param>
-        [Obsolete("Use the Play() overload.")]
-        public IPlayingAudioStream PlayGlobal(string filename, AudioParams? audioParams = null, Func<IPlayerSession, bool>? predicate = null, IPlayerSession? excludedSession = null)
-        {
-            var id = CacheIdentifier();
-            var msg = new PlayAudioGlobalMessage
-            {
-                FileName = filename,
-                AudioParams = audioParams ?? AudioParams.Default,
-                Identifier = id
-            };
-
-            if (predicate == null && excludedSession == null)
-            {
-                RaiseNetworkEvent(msg);
-                return new AudioSourceServer(this, id);
-            }
-
-            IList<IPlayerSession> players = predicate != null ? _playerManager.GetPlayersBy(predicate) : _playerManager.GetAllPlayers();
-
-            for (var i = players.Count - 1; i >= 0; i--)
-            {
-                var player = players[i];
-                if (player == excludedSession)
-                {
-                    players.RemoveAt(i);
-                    continue;
-                }
-
-                RaiseNetworkEvent(msg, player.ConnectedClient);
-            }
-
-            return new AudioSourceServer(this, id, players);
-        }
-
-        /// <summary>
-        ///     Play an audio file following an entity.
-        /// </summary>
-        /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
-        /// <param name="entity">The entity "emitting" the audio.</param>
-        /// <param name="audioParams"></param>
-        /// <param name="range">The max range at which the audio will be heard. Less than or equal to 0 to send to every player.</param>
-        /// <param name="excludedSession">Sessions that won't receive the audio message.</param>
-        [Obsolete("Use the Play() overload.")]
-        public IPlayingAudioStream PlayFromEntity(string filename, IEntity entity, AudioParams? audioParams = null, int range = AudioDistanceRange, IPlayerSession? excludedSession = null)
-        {
-            var id = CacheIdentifier();
-
-            var msg = new PlayAudioEntityMessage
-            {
-                FileName = filename,
-                Coordinates = entity.Transform.Coordinates,
-                EntityUid = entity.Uid,
-                AudioParams = audioParams ?? AudioParams.Default,
-                Identifier = id,
-            };
-
-            // send to every player
-            if (range <= 0 && excludedSession == null)
-            {
-                RaiseNetworkEvent(msg);
-                return new AudioSourceServer(this, id);
-            }
-
-            List<IPlayerSession> players;
-
-            if (range > 0.0f)
-                players = _playerManager.GetPlayersInRange(entity.Transform.Coordinates, range);
-            else
-                players = _playerManager.GetAllPlayers();
-
-            for (var i = players.Count - 1; i >= 0; i--)
-            {
-                var player = players[i];
-                if (player == excludedSession)
-                {
-                    players.RemoveAt(i);
-                    continue;
-                }
-
-                RaiseNetworkEvent(msg, player.ConnectedClient);
-            }
-
-            return new AudioSourceServer(this, id, players);
-        }
-
-        /// <summary>
-        ///     Play an audio file at a static position.
-        /// </summary>
-        /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
-        /// <param name="coordinates">The coordinates at which to play the audio.</param>
-        /// <param name="audioParams"></param>
-        /// <param name="range">The max range at which the audio will be heard. Less than or equal to 0 to send to every player.</param>
-        /// <param name="excludedSession">Session that won't receive the audio message.</param>
-        [Obsolete("Use the Play() overload.")]
-        public IPlayingAudioStream PlayAtCoords(string filename, EntityCoordinates coordinates, AudioParams? audioParams = null, int range = AudioDistanceRange, IPlayerSession? excludedSession = null)
-        {
-            var id = CacheIdentifier();
-            var msg = new PlayAudioPositionalMessage
-            {
-                FileName = filename,
-                Coordinates = coordinates,
-                AudioParams = audioParams ?? AudioParams.Default,
-                Identifier = id
-            };
-
-            if (range <= 0 && excludedSession == null)
-            {
-                RaiseNetworkEvent(msg);
-                return new AudioSourceServer(this, id);
-            }
-
-            List<IPlayerSession> players;
-
-            if (range > 0.0f)
-                players = _playerManager.GetPlayersInRange(coordinates, range);
-            else
-                players = _playerManager.GetAllPlayers();
-
-            for (var i = players.Count - 1; i >= 0; i--)
-            {
-                var player = players[i];
-                if (player == excludedSession)
-                {
-                    players.RemoveAt(i);
-                    continue;
-                }
-
-                RaiseNetworkEvent(msg, player.ConnectedClient);
-            }
-
-            return new AudioSourceServer(this, id, players);
-        }
-
         /// <inheritdoc />
         public int DefaultSoundRange => AudioDistanceRange;
 
@@ -214,7 +70,7 @@ namespace Robust.Server.GameObjects
         public int OcclusionCollisionMask { get; set; }
 
         /// <inheritdoc />
-        public IPlayingAudioStream? Play(Filter playerFilter, string filename, AudioParams? audioParams = null)
+        public IPlayingAudioStream Play(Filter playerFilter, string filename, AudioParams? audioParams = null)
         {
             var id = CacheIdentifier();
             var msg = new PlayAudioGlobalMessage
@@ -234,7 +90,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public IPlayingAudioStream? Play(Filter playerFilter, string filename, IEntity entity, AudioParams? audioParams = null)
+        public IPlayingAudioStream Play(Filter playerFilter, string filename, IEntity entity, AudioParams? audioParams = null)
         {
             //TODO: Calculate this from PAS
             var range = audioParams is null || audioParams.Value.MaxDistance <= 0 ? AudioDistanceRange : audioParams.Value.MaxDistance;
@@ -254,7 +110,7 @@ namespace Robust.Server.GameObjects
             var recipients = (playerFilter as IFilter).Recipients;
 
             if (range > 0.0f)
-                players = PASInRange(recipients, entity.Transform.MapPosition, range);
+                players = PasInRange(recipients, entity.Transform.MapPosition, range);
             else
                 players = recipients;
 
@@ -267,7 +123,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public IPlayingAudioStream? Play(Filter playerFilter, string filename, EntityCoordinates coordinates, AudioParams? audioParams = null)
+        public IPlayingAudioStream Play(Filter playerFilter, string filename, EntityCoordinates coordinates, AudioParams? audioParams = null)
         {
             //TODO: Calculate this from PAS
             var range = audioParams is null || audioParams.Value.MaxDistance <= 0 ? AudioDistanceRange : audioParams.Value.MaxDistance;
@@ -285,7 +141,7 @@ namespace Robust.Server.GameObjects
             var recipients = (playerFilter as IFilter).Recipients;
 
             if (range > 0.0f)
-                players = PASInRange(recipients, coordinates.ToMap(EntityManager), range);
+                players = PasInRange(recipients, coordinates.ToMap(EntityManager), range);
             else
                 players = recipients;
 
@@ -297,7 +153,7 @@ namespace Robust.Server.GameObjects
             return new AudioSourceServer(this, id, players);
         }
 
-        private static List<ICommonSession> PASInRange(IEnumerable<ICommonSession> players, MapCoordinates position, float range)
+        private static List<ICommonSession> PasInRange(IEnumerable<ICommonSession> players, MapCoordinates position, float range)
         {
             return players.Where(x =>
                     x.AttachedEntity != null &&

Robust.Server/GameObjects/EntitySystems/PhysicsSystem.cs

@@ -1,4 +1,6 @@
 using JetBrains.Annotations;
+using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
@@ -10,11 +12,19 @@ namespace Robust.Server.GameObjects
     public class PhysicsSystem : SharedPhysicsSystem
     {
         [Dependency] private readonly IMapManager _mapManager = default!;
+        [Dependency] private readonly IConfigurationManager _configurationManager = default!;
 
         public override void Initialize()
         {
             base.Initialize();
             _mapManager.OnGridCreated += HandleGridCreated;
+            LoadMetricCVar();
+            _configurationManager.OnValueChanged(CVars.MetricsEnabled, _ => LoadMetricCVar());
+        }
+
+        private void LoadMetricCVar()
+        {
+            MetricsEnabled = _configurationManager.GetCVar(CVars.MetricsEnabled);
         }
 
         public override void Shutdown()

Robust.Server/GameObjects/IServerEntityManager.cs

@@ -1,41 +1,9 @@
-using System.Collections.Generic;
-using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Timing;
 
 namespace Robust.Server.GameObjects
 {
-    public interface IServerEntityManager : IEntityManager
-    {
-        /// <summary>
-        ///     Gets all entity states that have been modified after and including the provided tick.
-        /// </summary>
-        List<EntityState>? GetEntityStates(GameTick fromTick, IPlayerSession player);
-
-        /// <summary>
-        ///     Gets all entity states within an AABB that have been modified after and including the provided tick.
-        /// </summary>
-        List<EntityState>? UpdatePlayerSeenEntityStates(GameTick fromTick, IPlayerSession player, float range);
-
-        // Keep track of deleted entities so we can sync deletions with the client.
-        /// <summary>
-        ///     Gets a list of all entity UIDs that were deleted between <paramref name="fromTick" /> and now.
-        /// </summary>
-        List<EntityUid>? GetDeletedEntities(GameTick fromTick);
-
-        /// <summary>
-        ///     Remove deletion history.
-        /// </summary>
-        /// <param name="toTick">The last tick to delete the history for. Inclusive.</param>
-        void CullDeletionHistory(GameTick toTick);
-
-        /// <summary>
-        ///     Removes entity state persistence information from the entity manager for a player.
-        /// </summary>
-        /// <param name="player"></param>
-        void DropPlayerState(IPlayerSession player);
-
-        float MaxUpdateRange { get; }
-
-    }
+    /// <summary>
+    /// Server side version of the <see cref="IEntityManager"/>.
+    /// </summary>
+    public interface IServerEntityManager : IEntityManager { }
 }

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -1,55 +1,29 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading;
+using System;
+using JetBrains.Annotations;
 using Prometheus;
-using Robust.Server.Player;
-using Robust.Shared;
-using Robust.Shared.Configuration;
-using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
 using Robust.Shared.Map;
-using Robust.Shared.Maths;
-using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
-using Robust.Shared.Utility;
-using static Robust.Shared.GameObjects.TransformComponent;
 
 namespace Robust.Server.GameObjects
 {
     /// <summary>
     /// Manager for entities -- controls things like template loading and instantiation
     /// </summary>
+    [UsedImplicitly] // DI Container
     public sealed class ServerEntityManager : EntityManager, IServerEntityManagerInternal
     {
         private static readonly Gauge EntitiesCount = Metrics.CreateGauge(
             "robust_entities_count",
             "Amount of alive entities.");
 
-        private const float MinimumMotionForMovers = 1 / 128f;
-
-        #region IEntityManager Members
-
-        [Shared.IoC.Dependency] private readonly IMapManager _mapManager = default!;
-        [Shared.IoC.Dependency] private readonly IPauseManager _pauseManager = default!;
-        [Shared.IoC.Dependency] private readonly IConfigurationManager _configurationManager = default!;
-
-        private float? _maxUpdateRangeCache;
-
-        public float MaxUpdateRange => _maxUpdateRangeCache
-            ??= _configurationManager.GetCVar(CVars.NetMaxUpdateRange);
+        [Dependency] private readonly IMapManager _mapManager = default!;
+        [Dependency] private readonly IPauseManager _pauseManager = default!;
 
         private int _nextServerEntityUid = (int) EntityUid.FirstUid;
 
-        private readonly List<(GameTick tick, EntityUid uid)> _deletionHistory = new();
-
-        public override void Update()
-        {
-            base.Update();
-            _maxUpdateRangeCache = null;
-        }
-
         /// <inheritdoc />
         public override IEntity CreateEntityUninitialized(string? prototypeName)
         {
@@ -79,33 +53,6 @@ namespace Robust.Server.GameObjects
             return newEntity;
         }
 
-        private Entity CreateEntityServer(string? prototypeName)
-        {
-            var entity = CreateEntity(prototypeName);
-
-            if (prototypeName != null)
-            {
-                var prototype = PrototypeManager.Index<EntityPrototype>(prototypeName);
-
-                // At this point in time, all data configure on the entity *should* be purely from the prototype.
-                // As such, we can reset the modified ticks to Zero,
-                // which indicates "not different from client's own deserialization".
-                // So the initial data for the component or even the creation doesn't have to be sent over the wire.
-                foreach (var component in ComponentManager.GetNetComponents(entity.Uid))
-                {
-                    // Make sure to ONLY get components that are defined in the prototype.
-                    // Others could be instantiated directly by AddComponent (e.g. ContainerManager).
-                    // And those aren't guaranteed to exist on the client, so don't clear them.
-                    if (prototype.Components.ContainsKey(component.Name))
-                    {
-                        ((Component) component).ClearTicks();
-                    }
-                }
-            }
-
-            return entity;
-        }
-
         /// <inheritdoc />
         public override IEntity SpawnEntity(string? protoName, EntityCoordinates coordinates)
         {
@@ -116,10 +63,7 @@ namespace Robust.Server.GameObjects
 
             InitializeAndStartEntity((Entity) entity);
 
-            if (_pauseManager.IsMapInitialized(coordinates.GetMapId(this)))
-            {
-                entity.RunMapInit();
-            }
+            if (_pauseManager.IsMapInitialized(coordinates.GetMapId(this))) entity.RunMapInit();
 
             return entity;
         }
@@ -133,728 +77,26 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public override IEntity SpawnEntityNoMapInit(string? protoName, EntityCoordinates coordinates)
+        public override void Startup()
         {
-            var newEnt = CreateEntityUninitialized(protoName, coordinates);
-            InitializeAndStartEntity((Entity) newEnt);
-            return newEnt;
+            base.Startup();
+            EntitySystemManager.Initialize();
+            Started = true;
         }
 
         /// <inheritdoc />
-        public List<EntityState>? GetEntityStates(GameTick fromTick, IPlayerSession player)
+        public override void TickUpdate(float frameTime, Histogram? histogram)
         {
-            var stateEntities = new List<EntityState>();
-            foreach (var entity in AllEntities)
-            {
-                if (entity.Deleted)
-                {
-                    continue;
-                }
+            base.TickUpdate(frameTime, histogram);
 
-                DebugTools.Assert(entity.Initialized);
-
-                if (entity.LastModifiedTick <= fromTick)
-                    continue;
-
-                stateEntities.Add(GetEntityState(ComponentManager, entity.Uid, fromTick, player));
-            }
-
-            // no point sending an empty collection
-            return stateEntities.Count == 0 ? default : stateEntities;
+            EntitiesCount.Set(AllEntities.Count);
         }
 
-        private readonly Dictionary<IPlayerSession, SortedSet<EntityUid>> _seenMovers
-            = new();
-
-        // Is thread safe.
-        private SortedSet<EntityUid> GetSeenMovers(IPlayerSession player)
-        {
-            lock (_seenMovers)
-            {
-                return GetSeenMoversUnlocked(player);
-            }
-        }
-
-        private SortedSet<EntityUid> GetSeenMoversUnlocked(IPlayerSession player)
-        {
-            if (!_seenMovers.TryGetValue(player, out var movers))
-            {
-                movers = new SortedSet<EntityUid>();
-                _seenMovers.Add(player, movers);
-            }
-
-            return movers;
-        }
-
-        private void AddToSeenMovers(IPlayerSession player, EntityUid entityUid)
-        {
-            var movers = GetSeenMoversUnlocked(player);
-
-            movers.Add(entityUid);
-        }
-
-        private readonly Dictionary<IPlayerSession, Dictionary<EntityUid, GameTick>> _playerLastSeen
-            = new();
-
-        private static readonly Vector2 Vector2NaN = new(float.NaN, float.NaN);
-
-        private Dictionary<EntityUid, GameTick> GetLastSeen(IPlayerSession player)
-        {
-            lock (_playerLastSeen)
-            {
-                if (!_playerLastSeen.TryGetValue(player, out var lastSeen))
-                {
-                    lastSeen = new Dictionary<EntityUid, GameTick>();
-                    _playerLastSeen.Add(player, lastSeen);
-                }
-
-                return lastSeen;
-            }
-        }
-
-        private static GameTick GetLastSeenTick(Dictionary<EntityUid, GameTick> lastSeen, EntityUid uid)
-        {
-            if (!lastSeen.TryGetValue(uid, out var tick))
-            {
-                tick = GameTick.First;
-            }
-
-            return tick;
-        }
-
-        private static GameTick UpdateLastSeenTick(Dictionary<EntityUid, GameTick> lastSeen, EntityUid uid, GameTick newTick)
-        {
-            if (!lastSeen.TryGetValue(uid, out var oldTick))
-            {
-                oldTick = GameTick.First;
-            }
-
-            lastSeen[uid] = newTick;
-
-            return oldTick;
-        }
-
-        private static IEnumerable<EntityUid> GetLastSeenAfter(Dictionary<EntityUid, GameTick> lastSeen, GameTick fromTick)
-        {
-            foreach (var (uid, tick) in lastSeen)
-            {
-                if (tick > fromTick)
-                {
-                    yield return uid;
-                }
-            }
-        }
-
-        private IEnumerable<EntityUid> GetLastSeenOn(Dictionary<EntityUid, GameTick> lastSeen, GameTick fromTick)
-        {
-            foreach (var (uid, tick) in lastSeen)
-            {
-                if (tick == fromTick)
-                {
-                    yield return uid;
-                }
-            }
-        }
-
-        private static void SetLastSeenTick(Dictionary<EntityUid, GameTick> lastSeen, EntityUid uid, GameTick tick)
-        {
-            lastSeen[uid] = tick;
-        }
-
-        private static void ClearLastSeenTick(Dictionary<EntityUid, GameTick> lastSeen, EntityUid uid)
-        {
-            lastSeen.Remove(uid);
-        }
-
-        public void DropPlayerState(IPlayerSession player)
-        {
-            lock (_playerLastSeen)
-            {
-                _playerLastSeen.Remove(player);
-            }
-        }
-
-        private void IncludeRelatives(IEnumerable<IEntity> children, HashSet<IEntity> set)
-        {
-            foreach (var child in children)
-            {
-                var ent = child!;
-
-                while (ent != null && !ent.Deleted)
-                {
-                    if (set.Add(ent))
-                    {
-                        AddContainedRecursive(ent, set);
-
-                        ent = ent.Transform.Parent?.Owner!;
-                    }
-                    else
-                    {
-                        // Already processed this entity once.
-                        break;
-                    }
-                }
-            }
-        }
-
-        private static void AddContainedRecursive(IEntity ent, HashSet<IEntity> set)
-        {
-            if (!ent.TryGetComponent(out ContainerManagerComponent? contMgr))
-            {
-                return;
-            }
-
-            foreach (var container in contMgr.GetAllContainers())
-            {
-                // Manual for loop to cut out allocations.
-                // ReSharper disable once ForCanBeConvertedToForeach
-                for (var i = 0; i < container.ContainedEntities.Count; i++)
-                {
-                    var contEnt = container.ContainedEntities[i];
-                    set.Add(contEnt);
-                    AddContainedRecursive(contEnt, set);
-                }
-            }
-        }
-
-        private class PlayerSeenEntityStatesResources
-        {
-            public readonly HashSet<EntityUid> IncludedEnts = new();
-
-            public readonly List<EntityState> EntityStates = new();
-
-            public readonly HashSet<EntityUid> NeededEnts = new();
-
-            public readonly HashSet<IEntity> Relatives = new();
-        }
-
-        private readonly ThreadLocal<PlayerSeenEntityStatesResources> _playerSeenEntityStatesResources
-            = new(() => new PlayerSeenEntityStatesResources());
-
-        /// <inheritdoc />
-        public List<EntityState>? UpdatePlayerSeenEntityStates(GameTick fromTick, IPlayerSession player, float range)
-        {
-            var playerEnt = player.AttachedEntity;
-            if (playerEnt == null)
-            {
-                // super-observer?
-                return GetEntityStates(fromTick, player);
-            }
-
-            var playerUid = playerEnt.Uid;
-
-            var transform = playerEnt.Transform;
-            var position = transform.WorldPosition;
-            var mapId = transform.MapID;
-            var viewbox = new Box2(position, position).Enlarged(MaxUpdateRange);
-
-            var seenMovers = GetSeenMovers(player);
-            var lSeen = GetLastSeen(player);
-
-            var pseStateRes = _playerSeenEntityStatesResources.Value!;
-            var checkedEnts = pseStateRes.IncludedEnts;
-            var entityStates = pseStateRes.EntityStates;
-            var neededEnts = pseStateRes.NeededEnts;
-            var relatives = pseStateRes.Relatives;
-            checkedEnts.Clear();
-            entityStates.Clear();
-            neededEnts.Clear();
-            relatives.Clear();
-
-            foreach (var uid in seenMovers.ToList())
-            {
-                if (!TryGetEntity(uid, out var entity) || entity.Deleted)
-                {
-                    seenMovers.Remove(uid);
-                    continue;
-                }
-
-                if (entity.TryGetComponent(out IPhysBody? body))
-                {
-                    if (body.LinearVelocity.EqualsApprox(Vector2.Zero, MinimumMotionForMovers))
-                    {
-                        if (AnyParentInSet(uid, seenMovers))
-                        {
-                            // parent is moving
-                            continue;
-                        }
-
-                        if (MathF.Abs(body.AngularVelocity) > 0)
-                        {
-                            if (entity.TryGetComponent(out TransformComponent? txf) && txf.ChildCount > 0)
-                            {
-                                // has children spinning
-                                continue;
-                            }
-                        }
-
-                        seenMovers.Remove(uid);
-                    }
-                }
-
-                var state = GetEntityState(ComponentManager, uid, fromTick, player);
-
-                if (checkedEnts.Add(uid))
-                {
-                    entityStates.Add(state);
-
-                    // mover did not change
-                    if (state.ComponentStates != null)
-                    {
-                        // mover can be seen
-                        if (!viewbox.Intersects(GetWorldAabbFromEntity(entity)))
-                        {
-                            // mover changed and can't be seen
-                            var idx = Array.FindIndex(state.ComponentStates,
-                                x => x is TransformComponentState);
-
-                            if (idx != -1)
-                            {
-                                // mover changed positional data and can't be seen
-                                var oldState =
-                                    (TransformComponentState) state.ComponentStates[idx];
-                                var newState = new TransformComponentState(Vector2NaN,
-                                    oldState.Rotation, oldState.ParentID, oldState.NoLocalRotation);
-                                state.ComponentStates[idx] = newState;
-                                seenMovers.Remove(uid);
-                                ClearLastSeenTick(lSeen, uid);
-
-                                checkedEnts.Add(uid);
-
-                                var needed = oldState.ParentID;
-                                if (!needed.IsValid() || checkedEnts.Contains(needed))
-                                {
-                                    // either no parent attached or parent already included
-                                    continue;
-                                }
-
-                                if (GetLastSeenTick(lSeen, needed) == GameTick.Zero)
-                                {
-                                    neededEnts.Add(needed);
-                                }
-                            }
-                        }
-                    }
-                }
-                else
-                {
-                    // mover already added?
-                    if (!viewbox.Intersects(GetWorldAabbFromEntity(entity)))
-                    {
-                        // mover can't be seen
-                        var oldState =
-                            (TransformComponentState) entity.Transform.GetComponentState(player);
-                        entityStates.Add(new EntityState(uid,
-                            new ComponentChanged[]
-                            {
-                                new(false, NetIDs.TRANSFORM, "Transform")
-                            },
-                            new ComponentState[]
-                            {
-                                new TransformComponentState(Vector2NaN, oldState.Rotation,
-                                    oldState.ParentID, oldState.NoLocalRotation)
-                            }));
-
-                        seenMovers.Remove(uid);
-                        ClearLastSeenTick(lSeen, uid);
-                        checkedEnts.Add(uid);
-
-                        var needed = oldState.ParentID;
-                        if (!needed.IsValid() || checkedEnts.Contains(needed))
-                        {
-                            // either no parent attached or parent already included
-                            continue;
-                        }
-
-                        if (GetLastSeenTick(lSeen, needed) == GameTick.Zero)
-                        {
-                            neededEnts.Add(needed);
-                        }
-                    }
-                }
-            }
-
-            var currentTick = CurrentTick;
-
-            // scan pvs box and include children and parents recursively
-            IncludeRelatives(GetEntitiesInRange(mapId, position, range, true), relatives);
-
-            // Exclude any entities that are currently invisible to the player.
-            ExcludeInvisible(relatives, player.VisibilityMask);
-
-            // Always send updates for all grid and map entities.
-            // If we don't, the client-side game state manager WILL blow up.
-            // TODO: Make map manager netcode aware of PVS to avoid the need for this workaround.
-            IncludeMapCriticalEntities(relatives);
-
-            foreach (var entity in relatives)
-            {
-                DebugTools.Assert(entity.Initialized && !entity.Deleted);
-
-                var lastChange = entity.LastModifiedTick;
-
-                var uid = entity.Uid;
-
-                var lastSeen = UpdateLastSeenTick(lSeen, uid, currentTick);
-
-                DebugTools.Assert(lastSeen != currentTick);
-
-                /*
-                if (uid != playerUid && entity.Prototype == playerEnt.Prototype && lastSeen < fromTick)
-                {
-                    Logger.DebugS("pvs", $"Player {playerUid} is seeing player {uid}.");
-                }
-                */
-
-                if (checkedEnts.Contains(uid))
-                {
-                    // already have it
-                    continue;
-                }
-
-                if (lastChange <= lastSeen)
-                {
-                    // hasn't changed since last seen
-                    continue;
-                }
-
-                // should this be lastSeen or fromTick?
-                var entityState = GetEntityState(ComponentManager, uid, lastSeen, player);
-
-                checkedEnts.Add(uid);
-
-                if (entityState.ComponentStates == null)
-                {
-                    // no changes
-                    continue;
-                }
-
-                entityStates.Add(entityState);
-
-                if (uid == playerUid)
-                {
-                    continue;
-                }
-
-                if (!entity.TryGetComponent(out IPhysBody? body))
-                {
-                    // can't be a mover w/o physics
-                    continue;
-                }
-
-                if (!body.LinearVelocity.EqualsApprox(Vector2.Zero, MinimumMotionForMovers))
-                {
-                    // has motion
-                    seenMovers.Add(uid);
-                }
-                else
-                {
-                    // not moving
-                    seenMovers.Remove(uid);
-                }
-            }
-
-            var priorTick = new GameTick(fromTick.Value - 1);
-            foreach (var uid in GetLastSeenOn(lSeen, priorTick))
-            {
-                if (checkedEnts.Contains(uid))
-                {
-                    continue;
-                }
-
-                if (uid == playerUid)
-                {
-                    continue;
-                }
-
-                if (!TryGetEntity(uid, out var entity) || entity.Deleted)
-                {
-                    // TODO: remove from states list being sent?
-                    continue;
-                }
-
-                if (viewbox.Intersects(GetWorldAabbFromEntity(entity)))
-                {
-                    // can be seen
-                    continue;
-                }
-
-                var state = GetEntityState(ComponentManager, uid, fromTick, player);
-
-                if (state.ComponentStates == null)
-                {
-                    // nothing changed
-                    continue;
-                }
-
-                checkedEnts.Add(uid);
-                entityStates.Add(state);
-
-                seenMovers.Remove(uid);
-                ClearLastSeenTick(lSeen, uid);
-
-                var idx = Array.FindIndex(state.ComponentStates, x => x is TransformComponentState);
-
-                if (idx == -1)
-                {
-                    // no transform changes
-                    continue;
-                }
-
-                var oldState = (TransformComponentState) state.ComponentStates[idx];
-                var newState =
-                    new TransformComponentState(Vector2NaN, oldState.Rotation, oldState.ParentID, oldState.NoLocalRotation);
-                state.ComponentStates[idx] = newState;
-
-
-                var needed = oldState.ParentID;
-                if (!needed.IsValid() || checkedEnts.Contains(needed))
-                {
-                    // don't need to include parent or already included
-                    continue;
-                }
-
-                if (GetLastSeenTick(lSeen, needed) == GameTick.First)
-                {
-                    neededEnts.Add(needed);
-                }
-            }
-
-            do
-            {
-                var moreNeededEnts = new HashSet<EntityUid>();
-
-                foreach (var uid in moreNeededEnts)
-                {
-                    if (checkedEnts.Contains(uid))
-                    {
-                        continue;
-                    }
-
-                    var entity = GetEntity(uid);
-                    var state = GetEntityState(ComponentManager, uid, fromTick, player);
-
-                    if (state.ComponentStates == null || viewbox.Intersects(GetWorldAabbFromEntity(entity)))
-                    {
-                        // no states or should already be seen
-                        continue;
-                    }
-
-
-                    checkedEnts.Add(uid);
-                    entityStates.Add(state);
-
-                    var idx = Array.FindIndex(state.ComponentStates,
-                        x => x is TransformComponentState);
-
-                    if (idx == -1)
-                    {
-                        // no transform state
-                        continue;
-                    }
-
-                    var oldState = (TransformComponentState) state.ComponentStates[idx];
-                    var newState =
-                        new TransformComponentState(Vector2NaN, oldState.Rotation,
-                            oldState.ParentID, oldState.NoLocalRotation);
-                    state.ComponentStates[idx] = newState;
-                    seenMovers.Remove(uid);
-
-                    ClearLastSeenTick(lSeen, uid);
-                    var needed = oldState.ParentID;
-
-                    if (!needed.IsValid() || checkedEnts.Contains(needed))
-                    {
-                        // done here
-                        continue;
-                    }
-
-                    // check if further needed
-                    if (!checkedEnts.Contains(uid) && GetLastSeenTick(lSeen, needed) == GameTick.Zero)
-                    {
-                        moreNeededEnts.Add(needed);
-                    }
-                }
-
-                neededEnts = moreNeededEnts;
-            } while (neededEnts.Count > 0);
-
-            // help the client out
-            entityStates.Sort((a, b) => a.Uid.CompareTo(b.Uid));
-
-#if DEBUG_NULL_ENTITY_STATES
-            foreach ( var state in entityStates ) {
-                if (state.ComponentStates == null)
-                {
-                    throw new NotImplementedException("Shouldn't send null states.");
-                }
-            }
-#endif
-
-            // no point sending an empty collection
-            return entityStates.Count == 0 ? default : entityStates;
-        }
-
-        public override void DeleteEntity(IEntity e)
-        {
-            base.DeleteEntity(e);
-            EventBus.RaiseEvent(EventSource.Local, new EntityDeletedMessage(e));
-            _deletionHistory.Add((CurrentTick, e.Uid));
-        }
-
-        public List<EntityUid>? GetDeletedEntities(GameTick fromTick)
-        {
-            var list = new List<EntityUid>();
-            foreach (var (tick, id) in _deletionHistory)
-            {
-                if (tick >= fromTick)
-                {
-                    list.Add(id);
-                }
-            }
-
-            // no point sending an empty collection
-            return list.Count == 0 ? default : list;
-        }
-
-        public void CullDeletionHistory(GameTick toTick)
-        {
-            _deletionHistory.RemoveAll(hist => hist.tick <= toTick);
-        }
-
-        public override bool UpdateEntityTree(IEntity entity, Box2? worldAABB = null)
-        {
-            var currentTick = CurrentTick;
-            var updated = base.UpdateEntityTree(entity, worldAABB);
-
-            if (entity.Deleted
-                || !entity.Initialized
-                || !Entities.ContainsKey(entity.Uid))
-            {
-                return updated;
-            }
-
-            DebugTools.Assert(entity.Transform.Initialized);
-
-            // note: updated can be false even if something moved a bit
-            worldAABB ??= GetWorldAabbFromEntity(entity);
-
-            foreach (var (player, lastSeen) in _playerLastSeen)
-            {
-                var playerEnt = player.AttachedEntity;
-                if (playerEnt == null)
-                {
-                    // player has no entity, gaf?
-                    continue;
-                }
-
-                var playerUid = playerEnt.Uid;
-
-                var entityUid = entity.Uid;
-
-                if (entityUid == playerUid)
-                {
-                    continue;
-                }
-
-                if (!lastSeen.TryGetValue(playerUid, out var playerTick))
-                {
-                    // player can't "see" itself, gaf?
-                    continue;
-                }
-
-                var playerPos = playerEnt.Transform.WorldPosition;
-
-                var viewbox = new Box2(playerPos, playerPos).Enlarged(MaxUpdateRange);
-
-                if (!lastSeen.TryGetValue(entityUid, out var tick))
-                {
-                    // never saw it other than first tick or was cleared
-                    if (!AnyParentMoving(player, entityUid))
-                    {
-                        continue;
-                    }
-                }
-
-                if (tick >= currentTick)
-                {
-                    // currently seeing it
-                    continue;
-                }
-                // saw it previously
-
-                // player can't see it now
-                if (!viewbox.Intersects(worldAABB.Value))
-                {
-                    var addToMovers = false;
-                    if (entity.Transform.LastModifiedTick >= currentTick)
-                    {
-                        addToMovers = true;
-                    }
-                    else if (entity.TryGetComponent(out IPhysBody? physics)
-                             && physics.LastModifiedTick >= currentTick)
-                    {
-                        addToMovers = true;
-                    }
-
-                    if (addToMovers)
-                    {
-                        AddToSeenMovers(player, entityUid);
-                    }
-                }
-            }
-
-            return updated;
-        }
-
-        private bool AnyParentMoving(IPlayerSession player, EntityUid entityUid)
-        {
-            var seenMovers = GetSeenMoversUnlocked(player);
-            if (seenMovers == null)
-            {
-                return false;
-            }
-
-            return AnyParentInSet(entityUid, seenMovers);
-        }
-
-        private bool AnyParentInSet(EntityUid entityUid, SortedSet<EntityUid> set)
-        {
-            for (;;)
-            {
-                if (!TryGetEntity(entityUid, out var ent))
-                {
-                    return false;
-                }
-
-                var txf = ent.Transform;
-
-                entityUid = txf.ParentUid;
-
-                if (entityUid == EntityUid.Invalid)
-                {
-                    return false;
-                }
-
-                if (set.Contains(entityUid))
-                {
-                    return true;
-                }
-            }
-        }
-
-        #endregion IEntityManager Members
-
         IEntity IServerEntityManagerInternal.AllocEntity(string? prototypeName, EntityUid? uid)
         {
             return AllocEntity(prototypeName, uid);
         }
 
-        protected override EntityUid GenerateEntityUid()
-        {
-            return new(_nextServerEntityUid++);
-        }
-
         void IServerEntityManagerInternal.FinishEntityLoad(IEntity entity, IEntityLoadContext? context)
         {
             LoadEntity((Entity) entity, context);
@@ -871,95 +113,33 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public override void Startup()
+        protected override EntityUid GenerateEntityUid()
         {
-            base.Startup();
-            EntitySystemManager.Initialize();
-            Started = true;
+            return new(_nextServerEntityUid++);
         }
 
-        /// <summary>
-        /// Generates a network entity state for the given entity.
-        /// </summary>
-        /// <param name="compMan">ComponentManager that contains the components for the entity.</param>
-        /// <param name="entityUid">Uid of the entity to generate the state from.</param>
-        /// <param name="fromTick">Only provide delta changes from this tick.</param>
-        /// <param name="player">The player to generate this state for.</param>
-        /// <returns>New entity State for the given entity.</returns>
-        private static EntityState GetEntityState(IComponentManager compMan, EntityUid entityUid, GameTick fromTick, IPlayerSession player)
+        private Entity CreateEntityServer(string? prototypeName)
         {
-            var compStates = new List<ComponentState>();
-            var changed = new List<ComponentChanged>();
+            var entity = CreateEntity(prototypeName);
 
-            foreach (var comp in compMan.GetNetComponents(entityUid))
+            if (prototypeName != null)
             {
-                DebugTools.Assert(comp.Initialized);
+                var prototype = PrototypeManager.Index<EntityPrototype>(prototypeName);
 
-                // NOTE: When LastModifiedTick or CreationTick are 0 it means that the relevant data is
-                // "not different from entity creation".
-                // i.e. when the client spawns the entity and loads the entity prototype,
-                // the data it deserializes from the prototype SHOULD be equal
-                // to what the component state / ComponentChanged would send.
-                // As such, we can avoid sending this data in this case since the client "already has it".
-
-                if (comp.NetSyncEnabled && comp.LastModifiedTick != GameTick.Zero && comp.LastModifiedTick >= fromTick)
-                    compStates.Add(comp.GetComponentState(player));
-
-                if (comp.CreationTick != GameTick.Zero && comp.CreationTick >= fromTick && !comp.Deleted)
+                // At this point in time, all data configure on the entity *should* be purely from the prototype.
+                // As such, we can reset the modified ticks to Zero,
+                // which indicates "not different from client's own deserialization".
+                // So the initial data for the component or even the creation doesn't have to be sent over the wire.
+                foreach (var component in ComponentManager.GetNetComponents(entity.Uid))
                 {
-                    // Can't be null since it's returned by GetNetComponents
-                    // ReSharper disable once PossibleInvalidOperationException
-                    changed.Add(ComponentChanged.Added(comp.NetID!.Value, comp.Name));
-                }
-                else if (comp.Deleted && comp.LastModifiedTick >= fromTick)
-                {
-                    // Can't be null since it's returned by GetNetComponents
-                    // ReSharper disable once PossibleInvalidOperationException
-                    changed.Add(ComponentChanged.Removed(comp.NetID!.Value));
+                    // Make sure to ONLY get components that are defined in the prototype.
+                    // Others could be instantiated directly by AddComponent (e.g. ContainerManager).
+                    // And those aren't guaranteed to exist on the client, so don't clear them.
+                    if (prototype.Components.ContainsKey(component.Name)) ((Component) component).ClearTicks();
                 }
             }
 
-            return new EntityState(entityUid, changed.ToArray(), compStates.ToArray());
-        }
-
-
-        private void IncludeMapCriticalEntities(HashSet<IEntity> set)
-        {
-            foreach (var mapId in _mapManager.GetAllMapIds())
-            {
-                if (_mapManager.HasMapEntity(mapId))
-                {
-                    set.Add(_mapManager.GetMapEntity(mapId));
-                }
-            }
-
-            foreach (var grid in _mapManager.GetAllGrids())
-            {
-                if (grid.GridEntityId != EntityUid.Invalid)
-                {
-                    set.Add(GetEntity(grid.GridEntityId));
-                }
-            }
-        }
-
-        private void ExcludeInvisible(HashSet<IEntity> set, int visibilityMask)
-        {
-            set.RemoveWhere(e =>
-            {
-                if (!e.TryGetComponent(out VisibilityComponent? visibility))
-                {
-                    return false;
-                }
-
-                return (visibilityMask & visibility.Layer) == 0;
-            });
-        }
-
-        public override void Update(float frameTime, Histogram? histogram)
-        {
-            base.Update(frameTime, histogram);
-
-            EntitiesCount.Set(AllEntities.Count);
+            return entity;
         }
     }
 }

Robust.Server/GameObjects/ServerEntityNetworkManager.cs

@@ -47,7 +47,7 @@ namespace Robust.Server.GameObjects
             _configurationManager.OnValueChanged(CVars.NetLogLateMsg, b => _logLateMsgs = b, true);
         }
 
-        public void Update()
+        public void TickUpdate()
         {
             while (_queue.Count != 0 && _queue.Peek().SourceTick <= _gameTiming.CurTick)
             {
@@ -87,7 +87,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntitySystemMessage message)
+        public void SendSystemNetworkMessage(EntityEventArgs message)
         {
             var newMsg = _networkManager.CreateNetMessage<MsgEntity>();
             newMsg.Type = EntityMessageType.SystemMessage;
@@ -98,7 +98,7 @@ namespace Robust.Server.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntitySystemMessage message, INetChannel targetConnection)
+        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel targetConnection)
         {
             var newMsg = _networkManager.CreateNetMessage<MsgEntity>();
             newMsg.Type = EntityMessageType.SystemMessage;

Robust.Server/GameStates/EntityViewCulling.cs

@@ -0,0 +1,324 @@
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using Microsoft.Extensions.ObjectPool;
+using Robust.Server.GameObjects;
+using Robust.Shared.Enums;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+using Robust.Shared.Players;
+using Robust.Shared.Timing;
+using Robust.Shared.Utility;
+
+namespace Robust.Server.GameStates
+{
+    internal class EntityViewCulling
+    {
+        private const int ViewSetCapacity = 128; // starting number of entities that are in view
+        private const int PlayerSetSize = 64; // Starting number of players
+        private const int MaxVisPoolSize = 1024; // Maximum number of pooled objects
+        
+        private static readonly Vector2 Vector2NaN = new(float.NaN, float.NaN);
+
+        private readonly IServerEntityManager _entMan;
+        private readonly IComponentManager _compMan;
+        private readonly IMapManager _mapManager;
+
+        private readonly Dictionary<ICommonSession, HashSet<EntityUid>> _playerVisibleSets = new(PlayerSetSize);
+
+        private readonly ConcurrentDictionary<ICommonSession, GameTick> _playerLastFullMap = new();
+
+        private readonly List<(GameTick tick, EntityUid uid)> _deletionHistory = new();
+
+        private readonly ObjectPool<HashSet<EntityUid>> _visSetPool
+            = new DefaultObjectPool<HashSet<EntityUid>>(new DefaultPooledObjectPolicy<HashSet<EntityUid>>(), MaxVisPoolSize);
+
+        private readonly ObjectPool<HashSet<EntityUid>> _viewerEntsPool
+            = new DefaultObjectPool<HashSet<EntityUid>>(new DefaultPooledObjectPolicy<HashSet<EntityUid>>(), MaxVisPoolSize);
+
+        /// <summary>
+        /// Is view culling enabled, or will we send the whole map?
+        /// </summary>
+        public bool CullingEnabled { get; set; }
+
+        /// <summary>
+        /// Size of the side of the view bounds square.
+        /// </summary>
+        public float ViewSize { get; set; }
+
+        public EntityViewCulling(IServerEntityManager entMan, IMapManager mapManager)
+        {
+            _entMan = entMan;
+            _compMan = entMan.ComponentManager;
+            _mapManager = mapManager;
+            _compMan = _entMan.ComponentManager;
+        }
+
+        // Not thread safe
+        public void EntityDeleted(EntityUid e)
+        {
+            // Not aware of prediction
+            _deletionHistory.Add((_entMan.CurrentTick, e));
+        }
+
+        // Not thread safe
+        public void CullDeletionHistory(GameTick oldestAck)
+        {
+            _deletionHistory.RemoveAll(hist => hist.tick < oldestAck);
+        }
+
+        private List<EntityUid> GetDeletedEntities(GameTick fromTick)
+        {
+            var list = new List<EntityUid>();
+            foreach (var (tick, id) in _deletionHistory)
+            {
+                if (tick >= fromTick) list.Add(id);
+            }
+
+            return list;
+        }
+
+        // Not thread safe
+        public void AddPlayer(ICommonSession session)
+        {
+            _playerVisibleSets.Add(session, new HashSet<EntityUid>(ViewSetCapacity));
+        }
+
+        // Not thread safe
+        public void RemovePlayer(ICommonSession session)
+        {
+            _playerVisibleSets.Remove(session);
+            _playerLastFullMap.Remove(session, out _);
+        }
+
+        // thread safe
+        public bool IsPointVisible(ICommonSession session, in MapCoordinates position)
+        {
+            var viewables = GetSessionViewers(session);
+
+            bool CheckInView(MapCoordinates mapCoordinates, HashSet<EntityUid> entityUids)
+            {
+                foreach (var euid in entityUids)
+                {
+                    var (viewBox, mapId) = CalcViewBounds(in euid);
+
+                    if (mapId != mapCoordinates.MapId)
+                        continue;
+
+                    if (!CullingEnabled)
+                        return true;
+
+                    if (viewBox.Contains(mapCoordinates.Position))
+                        return true;
+                }
+
+                return false;
+            }
+
+            bool result = CheckInView(position, viewables);
+
+            viewables.Clear();
+            _viewerEntsPool.Return(viewables);
+            return result;
+        }
+
+        private HashSet<EntityUid> GetSessionViewers(ICommonSession session)
+        {
+            var viewers = _viewerEntsPool.Get();
+            if (session.Status != SessionStatus.InGame || session.AttachedEntityUid is null)
+                return viewers;
+
+            var query = _compMan.EntityQuery<BasicActorComponent>();
+
+            foreach (var actorComp in query)
+            {
+                if (actorComp.playerSession == session)
+                    viewers.Add(actorComp.Owner.Uid);
+            }
+
+            return viewers;
+        }
+
+        // thread safe
+        public (List<EntityState>? updates, List<EntityUid>? deletions) CalculateEntityStates(ICommonSession session, GameTick fromTick, GameTick toTick)
+        {
+            DebugTools.Assert(session.Status == SessionStatus.InGame);
+
+            //TODO: Stop sending all entities to every player first tick
+            List<EntityUid>? deletions;
+            if (!CullingEnabled || fromTick == GameTick.Zero)
+            {
+                var allStates = ServerGameStateManager.GetAllEntityStates(_entMan, session, fromTick);
+                deletions = GetDeletedEntities(fromTick);
+                _playerLastFullMap.AddOrUpdate(session, toTick, (_, _) => toTick);
+                return (allStates, deletions);
+            }
+
+            var lastMapUpdate = _playerLastFullMap.GetValueOrDefault(session);
+            var currentSet = CalcCurrentViewSet(session);
+
+            // If they don't have a usable eye, nothing to send, and map remove will deal with ent removal
+            if (currentSet is null)
+                return (null, null);
+
+            deletions = GetDeletedEntities(fromTick);
+
+            // pretty big allocations :(
+            List<EntityState> entityStates = new(currentSet.Count);
+            var previousSet = _playerVisibleSets[session];
+
+            // complement set
+            foreach (var entityUid in previousSet)
+            {
+                if (!currentSet.Contains(entityUid) && !deletions.Contains(entityUid))
+                {
+                    if(_compMan.HasComponent<SnapGridComponent>(entityUid))
+                        continue;
+
+                    // PVS leave message
+                    //TODO: Remove NaN as the signal to leave PVS
+                    var xform = _compMan.GetComponent<ITransformComponent>(entityUid);
+                    var oldState = (TransformComponent.TransformComponentState)xform.GetComponentState(session);
+                    entityStates.Add(new EntityState(entityUid,
+                        new ComponentChanged[]
+                        {
+                            new(false, NetIDs.TRANSFORM, "Transform")
+                        },
+                        new ComponentState[]
+                        {
+                            new TransformComponent.TransformComponentState(Vector2NaN, oldState.Rotation,
+                                oldState.ParentID, oldState.NoLocalRotation)
+                        }));
+                }
+            }
+
+            foreach (var entityUid in currentSet)
+            {
+                if (previousSet.Contains(entityUid))
+                {
+                    //Still Visible
+                    // only send new changes
+                    var newState = ServerGameStateManager.GetEntityState(_entMan.ComponentManager, session, entityUid, fromTick);
+
+                    if (!newState.Empty)
+                        entityStates.Add(newState);
+                }
+                else
+                {
+                    // PVS enter message
+
+                    // skip sending anchored entities (walls)
+                    if (_compMan.HasComponent<SnapGridComponent>(entityUid) && _entMan.GetEntity(entityUid).LastModifiedTick <= lastMapUpdate)
+                        continue;
+
+                    // don't assume the client knows anything about us
+                    var newState = ServerGameStateManager.GetEntityState(_entMan.ComponentManager, session, entityUid, GameTick.Zero);
+                    entityStates.Add(newState);
+                }
+            }
+
+            // swap out vis sets
+            _playerVisibleSets[session] = currentSet;
+            previousSet.Clear();
+            _visSetPool.Return(previousSet);
+
+            // no point sending an empty collection
+            deletions = deletions?.Count == 0 ? default : deletions;
+
+            return (entityStates, deletions);
+        }
+
+        private HashSet<EntityUid>? CalcCurrentViewSet(ICommonSession session)
+        {
+            if (!CullingEnabled)
+                return null;
+
+            // if you don't have an attached entity, you don't see the world.
+            if (session.AttachedEntityUid is null)
+                return null;
+
+            var visibleEnts = _visSetPool.Get();
+            var viewers = GetSessionViewers(session);
+
+            foreach (var eyeEuid in viewers)
+            {
+                var (viewBox, mapId) = CalcViewBounds(in eyeEuid);
+
+                uint visMask = 0;
+                if (_compMan.TryGetComponent<EyeComponent>(eyeEuid, out var eyeComp))
+                    visMask = eyeComp.VisibilityMask;
+
+                //Always include the map entity
+                visibleEnts.Add(_mapManager.GetMapEntityId(mapId));
+
+                //Always include viewable ent itself
+                visibleEnts.Add(eyeEuid);
+
+                // grid entity should be added through this
+                // assume there are no deleted ents in here, cull them first in ent/comp manager
+                _entMan.FastEntitiesIntersecting(in mapId, ref viewBox, entity => RecursiveAdd((TransformComponent)entity.Transform, visibleEnts, visMask));
+            }
+
+            viewers.Clear();
+            _viewerEntsPool.Return(viewers);
+
+            return visibleEnts;
+        }
+
+        // Read Safe
+
+        [MethodImpl(MethodImplOptions.AggressiveOptimization)]
+        private bool RecursiveAdd(TransformComponent xform, HashSet<EntityUid> visSet, uint visMask)
+        {
+            var xformUid = xform.Owner.Uid;
+
+            // we are done, this ent has already been checked and is visible
+            if (visSet.Contains(xformUid))
+                return true;
+
+            // if we are invisible, we are not going into the visSet, so don't worry about parents, and children are not going in
+            if (_compMan.TryGetComponent<VisibilityComponent>(xformUid, out var visComp))
+            {
+                if ((visMask & visComp.Layer) == 0)
+                    return false;
+            }
+
+            var xformParentUid = xform.ParentUid;
+            
+            // this is the world entity, it is always visible
+            if (!xformParentUid.IsValid())
+            {
+                visSet.Add(xformUid);
+                return true;
+            }
+
+            // parent is already in the set
+            if (visSet.Contains(xformParentUid))
+            {
+                visSet.Add(xformUid);
+                return true;
+            }
+
+            // parent was not added, so we are not either
+            var xformParent = _compMan.GetComponent<TransformComponent>(xformParentUid);
+            if (!RecursiveAdd(xformParent, visSet, visMask))
+                return false;
+
+            // add us
+            visSet.Add(xformUid);
+            return true;
+        }
+
+        // Read Safe
+        private (Box2 view, MapId mapId) CalcViewBounds(in EntityUid euid)
+        {
+            var xform = _compMan.GetComponent<ITransformComponent>(euid);
+
+            var view = Box2.UnitCentered.Scale(ViewSize).Translated(xform.WorldPosition);
+            var map = xform.MapID;
+
+            return (view, map);
+        }
+    }
+}

Robust.Server/GameStates/IServerGameStateManager.cs

@@ -1,18 +1,21 @@
 namespace Robust.Server.GameStates
 {
     /// <summary>
-    ///     Engine service that provides creating and dispatching of game states.
+    /// Engine service that provides creating and dispatching of game states.
     /// </summary>
     public interface IServerGameStateManager
     {
         /// <summary>
-        ///     One time initialization of the service.
+        /// One time initialization of the service.
         /// </summary>
         void Initialize();
 
         /// <summary>
-        ///     Create and dispatch game states to all connected sessions.
+        /// Create and dispatch game states to all connected sessions.
         /// </summary>
         void SendGameStateUpdate();
+
+        bool PvsEnabled { get; }
+        float PvsRange { get; }
     }
 }

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using Robust.Server.GameObjects;
 using Robust.Server.Player;
 using Robust.Shared;
@@ -9,22 +10,24 @@ using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
 namespace Robust.Server.GameStates
 {
-    /// <inheritdoc />
-    public class ServerGameStateManager : IServerGameStateManager
+    /// <inheritdoc cref="IServerGameStateManager"/>
+    public class ServerGameStateManager : IServerGameStateManager, IPostInjectInit
     {
         // Mapping of net UID of clients -> last known acked state.
         private readonly Dictionary<long, GameTick> _ackedStates = new();
         private GameTick _lastOldestAck = GameTick.Zero;
 
+        private EntityViewCulling _entityView = null!;
+
         [Dependency] private readonly IServerEntityManager _entityManager = default!;
         [Dependency] private readonly IGameTiming _gameTiming = default!;
         [Dependency] private readonly IServerNetManager _networkManager = default!;
@@ -35,6 +38,12 @@ namespace Robust.Server.GameStates
         [Dependency] private readonly IConfigurationManager _configurationManager = default!;
 
         public bool PvsEnabled => _configurationManager.GetCVar(CVars.NetPVS);
+        public float PvsRange => _configurationManager.GetCVar(CVars.NetMaxUpdateRange);
+
+        public void PostInject()
+        {
+            _entityView = new EntityViewCulling(_entityManager, _mapManager);
+        }
 
         /// <inheritdoc />
         public void Initialize()
@@ -44,6 +53,27 @@ namespace Robust.Server.GameStates
 
             _networkManager.Connected += HandleClientConnected;
             _networkManager.Disconnect += HandleClientDisconnect;
+
+            _playerManager.PlayerStatusChanged += HandlePlayerStatusChanged;
+
+            _entityManager.EntityDeleted += HandleEntityDeleted;
+        }
+
+        private void HandleEntityDeleted(object? sender, EntityUid e)
+        {
+            _entityView.EntityDeleted(e);
+        }
+
+        private void HandlePlayerStatusChanged(object? sender, SessionStatusEventArgs e)
+        {
+            if (e.NewStatus == SessionStatus.InGame)
+            {
+                _entityView.AddPlayer(e.Session);
+            }
+            else if(e.OldStatus == SessionStatus.InGame)
+            {
+                _entityView.RemovePlayer(e.Session);
+            }
         }
 
         private void HandleClientConnected(object? sender, NetChannelArgs e)
@@ -57,13 +87,6 @@ namespace Robust.Server.GameStates
         private void HandleClientDisconnect(object? sender, NetChannelArgs e)
         {
             _ackedStates.Remove(e.Channel.ConnectionId);
-
-            if (!_playerManager.TryGetSessionByChannel(e.Channel, out var session))
-            {
-                return;
-            }
-
-            _entityManager.DropPlayerState(session);
         }
 
         private void HandleStateAck(MsgStateAck msg)
@@ -98,12 +121,13 @@ namespace Robust.Server.GameStates
         {
             DebugTools.Assert(_networkManager.IsServer);
 
-            _entityManager.Update();
+            _entityView.ViewSize = PvsRange * 2;
+            _entityView.CullingEnabled = PvsEnabled;
 
             if (!_networkManager.IsConnected)
             {
                 // Prevent deletions piling up if we have no clients.
-                _entityManager.CullDeletionHistory(GameTick.MaxValue);
+                _entityView.CullDeletionHistory(GameTick.MaxValue);
                 _mapManager.CullDeletionHistory(GameTick.MaxValue);
                 return;
             }
@@ -112,16 +136,14 @@ namespace Robust.Server.GameStates
 
             var oldestAck = GameTick.MaxValue;
 
-            var oldDeps = IoCManager.Resolve<IDependencyCollection>();
-
-            var deps = new DependencyCollection();
-            deps.RegisterInstance<ILogManager>(new ProxyLogManager(IoCManager.Resolve<ILogManager>()));
-            deps.BuildGraph();
-
+            var mainThread = Thread.CurrentThread;
             (MsgState, INetChannel) GenerateMail(IPlayerSession session)
             {
-                IoCManager.InitThread(deps, true);
+                // KILL IT WITH FIRE
+                if(mainThread != Thread.CurrentThread)
+                    IoCManager.InitThread(new DependencyCollection(), true);
 
+                // people not in the game don't get states
                 if (session.Status != SessionStatus.InGame)
                 {
                     return default;
@@ -134,11 +156,8 @@ namespace Robust.Server.GameStates
                     DebugTools.Assert("Why does this channel not have an entry?");
                 }
 
-                var entStates = lastAck == GameTick.Zero || !PvsEnabled
-                    ? _entityManager.GetEntityStates(lastAck, session)
-                    : _entityManager.UpdatePlayerSeenEntityStates(lastAck, session, _entityManager.MaxUpdateRange);
+                var (entStates, deletions) = _entityView.CalculateEntityStates(session, lastAck, _gameTiming.CurTick);
                 var playerStates = _playerManager.GetPlayerStates(lastAck);
-                var deletions = _entityManager.GetDeletedEntities(lastAck);
                 var mapData = _mapManager.GetStateData(lastAck);
 
                 // lastAck varies with each client based on lag and such, we can't just make 1 global state and send it to everyone
@@ -167,15 +186,9 @@ namespace Robust.Server.GameStates
             }
 
             var mailBag = _playerManager.GetAllPlayers()
-                .AsParallel().Select(GenerateMail).ToList();
-
-            // TODO: oh god oh fuck kill it with fire.
-            // PLINQ *seems* to be scheduling to the main thread partially (I guess that makes sense?)
-            // Which causes that IoC "hack" up there to override IoC in the main thread, nuking the game.
-            // At least, that's our running theory. I reproduced it once locally and can't reproduce it again.
-            // Throwing shit at the wall to hope it fixes it.
-            IoCManager.InitThread(oldDeps, true);
-
+                .AsParallel()
+                .Where(s=>s.Status == SessionStatus.InGame).Select(GenerateMail);
+            
             foreach (var (msg, chan) in mailBag)
             {
                 // see session.Status != SessionStatus.InGame above
@@ -187,9 +200,78 @@ namespace Robust.Server.GameStates
             if (oldestAck > _lastOldestAck)
             {
                 _lastOldestAck = oldestAck;
-                _entityManager.CullDeletionHistory(oldestAck);
+                _entityView.CullDeletionHistory(oldestAck);
                 _mapManager.CullDeletionHistory(oldestAck);
             }
         }
+
+        /// <summary>
+        /// Generates a network entity state for the given entity.
+        /// </summary>
+        /// <param name="compMan">ComponentManager that contains the components for the entity.</param>
+        /// <param name="player">The player to generate this state for.</param>
+        /// <param name="entityUid">Uid of the entity to generate the state from.</param>
+        /// <param name="fromTick">Only provide delta changes from this tick.</param>
+        /// <returns>New entity State for the given entity.</returns>
+        internal static EntityState GetEntityState(IComponentManager compMan, ICommonSession player, EntityUid entityUid, GameTick fromTick)
+        {
+            var compStates = new List<ComponentState>();
+            var changed = new List<ComponentChanged>();
+
+            foreach (var comp in compMan.GetNetComponents(entityUid))
+            {
+                DebugTools.Assert(comp.Initialized);
+
+                // NOTE: When LastModifiedTick or CreationTick are 0 it means that the relevant data is
+                // "not different from entity creation".
+                // i.e. when the client spawns the entity and loads the entity prototype,
+                // the data it deserializes from the prototype SHOULD be equal
+                // to what the component state / ComponentChanged would send.
+                // As such, we can avoid sending this data in this case since the client "already has it".
+
+                if (comp.NetSyncEnabled && comp.LastModifiedTick != GameTick.Zero && comp.LastModifiedTick >= fromTick)
+                    compStates.Add(comp.GetComponentState(player));
+
+                if (comp.CreationTick != GameTick.Zero && comp.CreationTick >= fromTick && !comp.Deleted)
+                {
+                    // Can't be null since it's returned by GetNetComponents
+                    // ReSharper disable once PossibleInvalidOperationException
+                    changed.Add(ComponentChanged.Added(comp.NetID!.Value, comp.Name));
+                }
+                else if (comp.Deleted && comp.LastModifiedTick >= fromTick)
+                {
+                    // Can't be null since it's returned by GetNetComponents
+                    // ReSharper disable once PossibleInvalidOperationException
+                    changed.Add(ComponentChanged.Removed(comp.NetID!.Value));
+                }
+            }
+
+            return new EntityState(entityUid, changed.ToArray(), compStates.ToArray());
+        }
+
+        /// <summary>
+        ///     Gets all entity states that have been modified after and including the provided tick.
+        /// </summary>
+        internal static List<EntityState>? GetAllEntityStates(IEntityManager entityMan, ICommonSession player, GameTick fromTick)
+        {
+            var stateEntities = new List<EntityState>();
+            foreach (var entity in entityMan.GetEntities())
+            {
+                if (entity.Deleted)
+                {
+                    continue;
+                }
+
+                DebugTools.Assert(entity.Initialized);
+
+                if (entity.LastModifiedTick <= fromTick)
+                    continue;
+
+                stateEntities.Add(GetEntityState(entityMan.ComponentManager, player, entity.Uid, fromTick));
+            }
+
+            // no point sending an empty collection
+            return stateEntities.Count == 0 ? default : stateEntities;
+        }
     }
 }