Version: 167.0.1

(cherry picked from commit 24d5c26fa6)
(cherry picked from commit 688efac67b634c613539b783a9fb6e679948cd53)

.github/CODEOWNERS

@@ -7,6 +7,3 @@
 **/Toolshed/** @moonheart08
 *Command.cs @moonheart08
 *Commands.cs @moonheart08
-
-# Physics
-**/Robust.Shared/Physics/** @metalgearsloth

MSBuild/Robust.Engine.Version.props

@@ -1,4 +1,4 @@
 <Project>
 
-    <!-- This file automatically reset by Tools/version.py -->
+    <!-- This file automatically reset by Tools/version.py -->
 

RELEASE-NOTES.md

@@ -54,151 +54,7 @@ END TEMPLATE-->
 *None yet*
 
 
-## 176.0.0
-
-### Breaking changes
-
-* Reverted audio rework temporarily until packaging is fixed.
-* Changes to Robust.Packaging to facilitate Content.Packaging ports from the python packaging scripts.
-
-### New features
-
-* Add a cvar for max game state buffer size.
-* Add an overload for GetEntitiesInRange that takes in a set.
-
-### Bugfixes
-
-* Fix PVS initial list capacity always being 0.
-* Fix replay lerp error spam.
-
-
-## 175.0.0
-
-### Breaking changes
-
-* Removed static SoundSystem.Play methods.
-* Moved IPlayingAudioStream onto AudioComponent and entities instead of an abstract stream.
-* IResourceCache is in shared and IClientResourceCache is the client version to use for textures.
-* Default audio attenuation changed from InverseDistanceClamped to LinearDistanceClamped.
-* Removed per-source audio attenuation.
-
-### New features
-
-* Add preliminary support for EFX Reverb presets + auxiliary slots; these are also entities.
-* Audio on grid entities is now attached to the grid.
-
-### Bugfixes
-
-* If an audio entity comes into PVS range its track will start at the relevant offset and not the beginning.
-* Z-Axis offset is considered for ReferenceDistance / MaxDistance for audio.
-* Audio will now pause if the attached entity is paused.
-
-### Other
-
-* Changed audio Z-Axis offset from -5m to -1m.
-
-
-## 174.0.0
-
-### Breaking changes
-
-* ActorComponent has been moved to `Robust.Shared.Player` (namespace changed).
-
-### New features
-
-* Added `SpriteSystem.GetFrame()` method, which takes in an animated RSI and a time and returns a frame/texture.
-* Added `IRobustRandom.NextAngle()`
-
-
-## 173.1.0
-
-### New features
-
-* Add physics chain shapes from Box2D.
-
-
-## 173.0.0
-
-### Breaking changes
-
-* Remove GridModifiedEvent in favor of TileChangedEvent.
-
-### Bugfixes
-
-* Fix some grid rendering bugs where chunks don't get destroyed correctly.
-
-
-## 172.0.0
-
-### Breaking changes
-
-* Remove TryLifestage helper methods.
-* Refactor IPlayerManager to remove more IPlayerSession, changed PlayerAttachedEvent etc on client to have the Local prefix, and shuffled namespaces around.
-
-### New features
-
-* Add EnsureComponent(ref Entity<\T?>)
-
-### Bugfixes
-
-* Re-add force ask threshold and fix other PVS bugs.
-
-
-## 171.0.0
-
-### Breaking changes
-
-* Change PlaceNextTo method names to be more descriptive.
-* Rename RefreshRelay for joints to SetRelay to match its behaviour.
-
-### Bugfixes
-
-* Fix PVS error spam for joint relays not being cleaned up.
-
-### Other
-
-* Set EntityLastModifiedTick on entity spawn.
-
-
-## 170.0.0
-
-### Breaking changes
-
-* Removed obsolete methods and properties in VisibilitySystem, SharedContainerSystem and MetaDataComponent.
-
-### Bugfixes
-
-* Fixed duplicate command error.
-* Fixed not being able to delete individual entities with the delete command.
-
-### Other
-
-* FileLogHandler logs can now be deleted while the engine is running.
-
-
-## 169.0.1
-
-### Other
-
-* The client now knows about registered server-side toolshed commands.
-
-## 169.0.0
-
-### Breaking changes
-
-* Entity<T> has been introduced to hold a component and its owning entity. Some methods that returned and accepted components directly have been removed or obsoleted to reflect this.
-
-### Other
-
-* By-value events may now be subscribed to by-ref.
-* The manifest's assemblyPrefix value is now respected on the server.
-
-
-## 168.0.0
-
-### Breaking changes
-
-* The Component.OnRemove method has been removed. Use SubscribeLocalEvent<TComp, ComponentRemove>(OnRemove) from an EntitySystem instead.
+## 167.0.1
 
 
 ## 167.0.0
@@ -245,7 +101,7 @@ END TEMPLATE-->
 
 ### New features
 
-* The YAML validator now checks the default values of ProtoId<T> and EntProtoId data fields.
+* The YAML validator now checks the default values of ProtoId<T> and EntProtoId data fields. 
 
 ### Bugfixes
 

Resources/Locale/en-US/commands.ftl

@@ -17,15 +17,15 @@ cmd-error-dir-not-found = Could not find directory: {$dir}.
 cmd-failure-no-attached-entity = There is no entity attached to this shell.
 
 ## 'help' command
-cmd-help-desc = Display general help or help text for a specific command
-cmd-help-help = Usage: help [command name]
+cmd-oldhelp-desc = Display general help or help text for a specific command
+cmd-oldhelp-help = Usage: help [command name]
     When no command name is provided, displays general-purpose help text. If a command name is provided, displays help text for that command.
 
-cmd-help-no-args = To display help for a specific command, write 'help <command>'. To list all available commands, write 'list'. To search for commands, use 'list <filter>'.
-cmd-help-unknown = Unknown command: { $command }
-cmd-help-top = { $command } - { $description }
-cmd-help-invalid-args = Invalid amount of arguments.
-cmd-help-arg-cmdname = [command name]
+cmd-oldhelp-no-args = To display help for a specific command, write 'help <command>'. To list all available commands, write 'list'. To search for commands, use 'list <filter>'.
+cmd-oldhelp-unknown = Unknown command: { $command }
+cmd-oldhelp-top = { $command } - { $description }
+cmd-oldhelp-invalid-args = Invalid amount of arguments.
+cmd-oldhelp-arg-cmdname = [command name]
 
 ## 'cvar' command
 cmd-cvar-desc = Gets or sets a CVar.

Robust.Analyzers/ByRefEventAnalyzer.cs

@@ -23,6 +23,16 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
         "Make sure that methods subscribing to a ref event have the ref keyword for the event argument."
     );
 
+    private static readonly DiagnosticDescriptor ByValueEventSubscribedByRefRule = new(
+        Diagnostics.IdValueEventRaisedByRef,
+        "Value event subscribed to by-ref",
+        "Tried to subscribe to a value event '{0}' by-ref.",
+        "Usage",
+        DiagnosticSeverity.Error,
+        true,
+        "Make sure that methods subscribing to value events do not have the ref keyword for the event argument."
+    );
+
     private static readonly DiagnosticDescriptor ByRefEventRaisedByValueRule = new(
         Diagnostics.IdByRefEventRaisedByValue,
         "By-ref event raised by value",
@@ -45,6 +55,7 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
 
     public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(
         ByRefEventSubscribedByValueRule,
+        ByValueEventSubscribedByRefRule,
         ByRefEventRaisedByValueRule,
         ByValueEventRaisedByRefRule
     );
@@ -53,9 +64,71 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
     {
         context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);
         context.EnableConcurrentExecution();
+        context.RegisterOperationAction(CheckEventSubscription, OperationKind.Invocation);
         context.RegisterOperationAction(CheckEventRaise, OperationKind.Invocation);
     }
 
+    private void CheckEventSubscription(OperationAnalysisContext context)
+    {
+        if (context.Operation is not IInvocationOperation operation)
+            return;
+
+        var subscribeMethods = context.Compilation
+            .GetTypeByMetadataName("Robust.Shared.GameObjects.EntitySystem")?
+            .GetMembers()
+            .Where(m => m.Name.Contains("SubscribeLocalEvent"))
+            .Cast<IMethodSymbol>();
+
+        if (subscribeMethods == null)
+            return;
+
+        if (!subscribeMethods.Any(m => m.Equals(operation.TargetMethod.OriginalDefinition, Default)))
+            return;
+
+        var typeArguments = operation.TargetMethod.TypeArguments;
+        if (typeArguments.Length < 1 || typeArguments.Length > 2)
+            return;
+
+        if (operation.Arguments.First().Value is not IDelegateCreationOperation delegateCreation)
+            return;
+
+        if (delegateCreation.Target is not IMethodReferenceOperation methodReference)
+            return;
+
+        var eventParameter = methodReference.Method.Parameters.LastOrDefault();
+        if (eventParameter == null)
+            return;
+
+        ITypeSymbol eventArgument;
+        switch (typeArguments.Length)
+        {
+            case 1:
+                eventArgument = typeArguments[0];
+                break;
+            case 2:
+                eventArgument = typeArguments[1];
+                break;
+            default:
+                return;
+        }
+
+        var byRefAttribute = context.Compilation.GetTypeByMetadataName(ByRefAttribute);
+        if (byRefAttribute == null)
+            return;
+
+        var isByRefEventType = eventArgument
+            .GetAttributes()
+            .Any(attribute => attribute.AttributeClass?.Equals(byRefAttribute, Default) ?? false);
+        var parameterIsRef = eventParameter.RefKind == RefKind.Ref;
+
+        if (isByRefEventType != parameterIsRef)
+        {
+            var descriptor = isByRefEventType ? ByRefEventSubscribedByValueRule : ByValueEventSubscribedByRefRule;
+            var diagnostic = Diagnostic.Create(descriptor, operation.Syntax.GetLocation(), eventArgument);
+            context.ReportDiagnostic(diagnostic);
+        }
+    }
+
     private void CheckEventRaise(OperationAnalysisContext context)
     {
         if (context.Operation is not IInvocationOperation operation)

Robust.Analyzers/Diagnostics.cs

@@ -18,6 +18,7 @@ public static class Diagnostics
     public const string IdInvalidNotNullableFlagType = "RA0011";
     public const string IdNotNullableFlagValueType = "RA0012";
     public const string IdByRefEventSubscribedByValue = "RA0013";
+    public const string IdValueEventSubscribedByRef = "RA0014";
     public const string IdByRefEventRaisedByValue = "RA0015";
     public const string IdValueEventRaisedByRef = "RA0016";
     public const string IdDataDefinitionPartial = "RA0017";

Robust.Benchmarks/Transform/RecursiveMoveBenchmark.cs

@@ -54,7 +54,7 @@ public class RecursiveMoveBenchmark
         var mapSys = _entMan.System<SharedMapSystem>();
         var mapId = mapMan.CreateMap();
         var map = mapMan.GetMapEntityId(mapId);
-        var gridComp = mapMan.CreateGridEntity(mapId);
+        var gridComp = mapMan.CreateGrid(mapId);
         var grid = gridComp.Owner;
         _gridCoords = new EntityCoordinates(grid, .5f, .5f);
         _mapCoords = new EntityCoordinates(map, 100, 100);

Robust.Client/BaseClient.cs

@@ -1,6 +1,8 @@
 using System;
+using System.Linq;
 using System.Net;
 using Robust.Client.Configuration;
+using Robust.Client.Debugging;
 using Robust.Client.GameObjects;
 using Robust.Client.GameStates;
 using Robust.Client.Player;
@@ -8,12 +10,13 @@ using Robust.Client.Utility;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.Enums;
+using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -62,12 +65,12 @@ namespace Robust.Client
 
             _configManager.OnValueChanged(CVars.NetTickrate, TickRateChanged, invokeImmediately: true);
 
-            _playMan.Initialize(0);
+            _playMan.Initialize();
             _playMan.PlayerListUpdated += OnPlayerListUpdated;
             Reset();
         }
 
-        private void OnPlayerListUpdated()
+        private void OnPlayerListUpdated(object? sender, EventArgs e)
         {
             var serverPlayers = _playMan.PlayerCount;
             if (_net.ServerChannel != null && GameInfo != null && _net.IsConnected)
@@ -127,10 +130,9 @@ namespace Robust.Client
         {
             DebugTools.Assert(RunLevel < ClientRunLevel.Connecting);
             DebugTools.Assert(!_net.IsConnected);
-            var name = PlayerNameOverride ?? _configManager.GetCVar(CVars.PlayerName);
-            _playMan.SetupSinglePlayer(name);
+            _playMan.Startup();
+            _playMan.LocalPlayer!.Name = PlayerNameOverride ?? _configManager.GetCVar(CVars.PlayerName);
             OnRunLevelChanged(ClientRunLevel.SinglePlayerGame);
-            _playMan.JoinGame(_playMan.LocalSession!);
             GameStartedSetup();
         }
 
@@ -171,14 +173,22 @@ namespace Robust.Client
                 info.ServerName = serverName;
             }
 
-            var channel = _net.ServerChannel!;
+            var maxPlayers = _configManager.GetCVar<int>("game.maxplayers");
+            info.ServerMaxPlayers = maxPlayers;
+
+            var userName = _net.ServerChannel!.UserName;
+            var userId = _net.ServerChannel.UserId;
 
             // start up player management
-            _playMan.SetupMultiplayer(channel);
-            _playMan.PlayerStatusChanged += OnStatusChanged;
+            _playMan.Startup();
+
+            _playMan.LocalPlayer!.UserId = userId;
+            _playMan.LocalPlayer.Name = userName;
+
+            _playMan.LocalPlayer.StatusChanged += OnLocalStatusChanged;
 
             var serverPlayers = _playMan.PlayerCount;
-            _discord.Update(info.ServerName, channel.UserName, info.ServerMaxPlayers.ToString(), serverPlayers.ToString());
+            _discord.Update(info.ServerName, userName, info.ServerMaxPlayers.ToString(), serverPlayers.ToString());
 
         }
 
@@ -211,8 +221,6 @@ namespace Robust.Client
 
         private void Reset()
         {
-            _configManager.ReceivedInitialNwVars -= OnReceivedClientData;
-            _playMan.PlayerStatusChanged -= OnStatusChanged;
             _configManager.ClearReceivedInitialNwVars();
             OnRunLevelChanged(ClientRunLevel.Initialize);
         }
@@ -255,17 +263,19 @@ namespace Robust.Client
             Reset();
         }
 
-        private void OnStatusChanged(object? sender, SessionStatusEventArgs e)
+        private void OnLocalStatusChanged(object? obj, StatusEventArgs eventArgs)
         {
-            if (e.Session != _playMan.LocalSession)
-                return;
-
             // player finished fully connecting to the server.
             // OldStatus is used here because it can go from connecting-> connected or connecting-> ingame
-            if (e.OldStatus == SessionStatus.Connecting)
-                OnPlayerJoinedServer(e.Session);
-            else if (e.NewStatus == SessionStatus.InGame)
-                OnPlayerJoinedGame(e.Session);
+            if (eventArgs.OldStatus == SessionStatus.Connecting)
+            {
+                OnPlayerJoinedServer(_playMan.LocalPlayer!.Session);
+            }
+
+            if (eventArgs.NewStatus == SessionStatus.InGame)
+            {
+                OnPlayerJoinedGame(_playMan.LocalPlayer!.Session);
+            }
         }
 
         private void OnRunLevelChanged(ClientRunLevel newRunLevel)

Robust.Client/ClientIoC.cs

@@ -37,7 +37,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Physics;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Replays;

Robust.Client/Console/ClientConsoleHost.cs

@@ -13,7 +13,7 @@ using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Reflection;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;

Robust.Client/Console/Commands/AddCompCommand.cs

@@ -26,7 +26,10 @@ namespace Robust.Client.Console.Commands
             var entity = _entityManager.GetEntity(netEntity);
             var componentName = args[1];
 
-            var component = _componentFactory.GetComponent(componentName);
+            var component = (Component) _componentFactory.GetComponent(componentName);
+
+            component.Owner = entity;
+
             _entityManager.AddComponent(entity, component);
         }
     }

Robust.Client/Debugging/DebugAnchoringSystem.cs

@@ -1,7 +1,6 @@
 #if DEBUG
 using System.Numerics;
 using System.Text;
-using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
 using Robust.Client.UserInterface;
@@ -9,6 +8,7 @@ using Robust.Client.UserInterface.Controls;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
+using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.Debugging
@@ -19,7 +19,6 @@ namespace Robust.Client.Debugging
         [Dependency] private readonly IInputManager _inputManager = default!;
         [Dependency] private readonly IMapManager _mapManager = default!;
         [Dependency] private readonly IUserInterfaceManager _userInterface = default!;
-        [Dependency] private readonly MapSystem _mapSystem = default!;
 
         private Label? _label;
 
@@ -71,7 +70,7 @@ namespace Robust.Client.Debugging
                 return;
             }
 
-            var tile = _mapSystem.GetTileRef(gridUid, grid, spot);
+            var tile = grid.GetTileRef(spot);
             _label.Position = mouseSpot.Position + new Vector2(32, 0);
 
             if (_hovered?.GridId == gridUid && _hovered?.Tile == tile) return;
@@ -80,7 +79,7 @@ namespace Robust.Client.Debugging
 
             var text = new StringBuilder();
 
-            foreach (var ent in _mapSystem.GetAnchoredEntities(gridUid, grid, spot))
+            foreach (var ent in grid.GetAnchoredEntities(spot))
             {
                 if (EntityManager.TryGetComponent<MetaDataComponent>(ent, out var meta))
                 {

Robust.Client/Debugging/DebugPhysicsSystem.cs

@@ -46,6 +46,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Numerics;
 using Robust.Client.Graphics;
 using Robust.Client.Input;
@@ -206,7 +207,6 @@ namespace Robust.Client.Debugging
         private readonly Font _font;
 
         private HashSet<Joint> _drawnJoints = new();
-        private List<Entity<MapGridComponent>> _grids = new();
 
         public PhysicsDebugOverlay(IEntityManager entityManager, IEyeManager eyeManager, IInputManager inputManager, IMapManager mapManager, IPlayerManager playerManager, IResourceCache cache, DebugPhysicsSystem system, EntityLookupSystem lookup, SharedPhysicsSystem physicsSystem)
         {
@@ -231,33 +231,32 @@ namespace Robust.Client.Debugging
             {
                 foreach (var physBody in _physicsSystem.GetCollidingEntities(mapId, viewBounds))
                 {
-                    if (_entityManager.HasComponent<MapGridComponent>(physBody)) continue;
+                    if (_entityManager.HasComponent<MapGridComponent>(physBody.Owner)) continue;
 
-                    var xform = _physicsSystem.GetPhysicsTransform(physBody);
-                    var comp = physBody.Comp;
+                    var xform = _physicsSystem.GetPhysicsTransform(physBody.Owner);
 
                     const float AlphaModifier = 0.2f;
 
-                    foreach (var fixture in _entityManager.GetComponent<FixturesComponent>(physBody).Fixtures.Values)
+                    foreach (var fixture in _entityManager.GetComponent<FixturesComponent>(physBody.Owner).Fixtures.Values)
                     {
                         // Invalid shape - Box2D doesn't check for IsSensor but we will for sanity.
-                        if (comp.BodyType == BodyType.Dynamic && fixture.Density == 0f && fixture.Hard)
+                        if (physBody.BodyType == BodyType.Dynamic && fixture.Density == 0f && fixture.Hard)
                         {
                             DrawShape(worldHandle, fixture, xform, Color.Red.WithAlpha(AlphaModifier));
                         }
-                        else if (!comp.CanCollide)
+                        else if (!physBody.CanCollide)
                         {
                             DrawShape(worldHandle, fixture, xform, new Color(0.5f, 0.5f, 0.3f).WithAlpha(AlphaModifier));
                         }
-                        else if (comp.BodyType == BodyType.Static)
+                        else if (physBody.BodyType == BodyType.Static)
                         {
                             DrawShape(worldHandle, fixture, xform, new Color(0.5f, 0.9f, 0.5f).WithAlpha(AlphaModifier));
                         }
-                        else if ((comp.BodyType & (BodyType.Kinematic | BodyType.KinematicController)) != 0x0)
+                        else if ((physBody.BodyType & (BodyType.Kinematic | BodyType.KinematicController)) != 0x0)
                         {
                             DrawShape(worldHandle, fixture, xform, new Color(0.5f, 0.5f, 0.9f).WithAlpha(AlphaModifier));
                         }
-                        else if (!comp.Awake)
+                        else if (!physBody.Awake)
                         {
                             DrawShape(worldHandle, fixture, xform, new Color(0.6f, 0.6f, 0.6f).WithAlpha(AlphaModifier));
                         }
@@ -276,18 +275,15 @@ namespace Robust.Client.Debugging
                 foreach (var physBody in _physicsSystem.GetCollidingEntities(mapId, viewBounds))
                 {
                     var color = Color.Purple.WithAlpha(Alpha);
-                    var transform = _physicsSystem.GetPhysicsTransform(physBody);
-                    worldHandle.DrawCircle(Transform.Mul(transform, physBody.Comp.LocalCenter), 0.2f, color);
+                    var transform = _physicsSystem.GetPhysicsTransform(physBody.Owner);
+                    worldHandle.DrawCircle(Transform.Mul(transform, physBody.LocalCenter), 0.2f, color);
                 }
 
-                _grids.Clear();
-                _mapManager.FindGridsIntersecting(mapId, viewBounds, ref _grids);
-
-                foreach (var grid in _grids)
+                foreach (var grid in _mapManager.FindGridsIntersecting(mapId, viewBounds))
                 {
-                    var physBody = _entityManager.GetComponent<PhysicsComponent>(grid);
+                    var physBody = _entityManager.GetComponent<PhysicsComponent>(grid.Owner);
                     var color = Color.Orange.WithAlpha(Alpha);
-                    var transform = _physicsSystem.GetPhysicsTransform(grid);
+                    var transform = _physicsSystem.GetPhysicsTransform(grid.Owner);
                     worldHandle.DrawCircle(Transform.Mul(transform, physBody.LocalCenter), 1f, color);
                 }
             }
@@ -296,14 +292,14 @@ namespace Robust.Client.Debugging
             {
                 foreach (var physBody in _physicsSystem.GetCollidingEntities(mapId, viewBounds))
                 {
-                    if (_entityManager.HasComponent<MapGridComponent>(physBody)) continue;
+                    if (_entityManager.HasComponent<MapGridComponent>(physBody.Owner)) continue;
 
-                    var xform = _physicsSystem.GetPhysicsTransform(physBody);
+                    var xform = _physicsSystem.GetPhysicsTransform(physBody.Owner);
 
                     const float AlphaModifier = 0.2f;
                     Box2? aabb = null;
 
-                    foreach (var fixture in _entityManager.GetComponent<FixturesComponent>(physBody).Fixtures.Values)
+                    foreach (var fixture in _entityManager.GetComponent<FixturesComponent>(physBody.Owner).Fixtures.Values)
                     {
                         for (var i = 0; i < fixture.Shape.ChildCount; i++)
                         {
@@ -322,11 +318,10 @@ namespace Robust.Client.Debugging
             {
                 _drawnJoints.Clear();
 
-                var query = _entityManager.AllEntityQueryEnumerator<JointComponent>();
-                while (query.MoveNext(out var uid, out var jointComponent))
+                foreach (var jointComponent in _entityManager.EntityQuery<JointComponent>(true))
                 {
                     if (jointComponent.JointCount == 0 ||
-                        !_entityManager.TryGetComponent(uid, out TransformComponent? xf1) ||
+                        !_entityManager.TryGetComponent(jointComponent.Owner, out TransformComponent? xf1) ||
                         !viewAABB.Contains(xf1.WorldPosition)) continue;
 
                     foreach (var (_, joint) in jointComponent.Joints)
@@ -366,9 +361,6 @@ namespace Robust.Client.Debugging
 
                 _debugPhysicsSystem.PointCount = 0;
             }
-
-            worldHandle.UseShader(null);
-            worldHandle.SetTransform(Matrix3.Identity);
         }
 
         private void DrawScreen(DrawingHandleScreen screenHandle, OverlayDrawArgs args)
@@ -378,31 +370,28 @@ namespace Robust.Client.Debugging
 
             if ((_debugPhysicsSystem.Flags & PhysicsDebugFlags.ShapeInfo) != 0x0)
             {
-                var hoverBodies = new List<Entity<PhysicsComponent>>();
+                var hoverBodies = new List<PhysicsComponent>();
                 var bounds = Box2.UnitCentered.Translated(_eyeManager.PixelToMap(mousePos.Position).Position);
 
                 foreach (var physBody in _physicsSystem.GetCollidingEntities(mapId, bounds))
                 {
-                    var uid = physBody.Owner;
-                    if (_entityManager.HasComponent<MapGridComponent>(uid)) continue;
-                    hoverBodies.Add((uid, physBody));
+                    if (_entityManager.HasComponent<MapGridComponent>(physBody.Owner)) continue;
+                    hoverBodies.Add(physBody);
                 }
 
                 var lineHeight = _font.GetLineHeight(1f);
                 var drawPos = mousePos.Position + new Vector2(20, 0) + new Vector2(0, -(hoverBodies.Count * 4 * lineHeight / 2f));
                 int row = 0;
 
-                foreach (var bodyEnt in hoverBodies)
+                foreach (var body in hoverBodies)
                 {
-                    if (bodyEnt != hoverBodies[0])
+                    if (body != hoverBodies[0])
                     {
                         screenHandle.DrawString(_font, drawPos + new Vector2(0, row * lineHeight), "------");
                         row++;
                     }
 
-                    var body = bodyEnt.Comp;
-
-                    screenHandle.DrawString(_font, drawPos + new Vector2(0, row * lineHeight), $"Ent: {bodyEnt.Owner}");
+                    screenHandle.DrawString(_font, drawPos + new Vector2(0, row * lineHeight), $"Ent: {body.Owner}");
                     row++;
                     screenHandle.DrawString(_font, drawPos + new Vector2(0, row * lineHeight), $"Layer: {Convert.ToString(body.CollisionLayer, 2)}");
                     row++;
@@ -441,9 +430,6 @@ namespace Robust.Client.Debugging
                     }
                 }
             }
-
-            screenHandle.UseShader(null);
-            screenHandle.SetTransform(Matrix3.Identity);
         }
 
         protected internal override void Draw(in OverlayDrawArgs args)
@@ -465,26 +451,11 @@ namespace Robust.Client.Debugging
         {
             switch (fixture.Shape)
             {
-                case ChainShape cShape:
-                {
-                    var count = cShape.Count;
-                    var vertices = cShape.Vertices;
-
-                    var v1 = Transform.Mul(xform, vertices[0]);
-                    for (var i = 1; i < count; ++i)
-                    {
-                        var v2 = Transform.Mul(xform, vertices[i]);
-                        worldHandle.DrawLine(v1, v2, color);
-                        v1 = v2;
-                    }
-                }
-                    break;
                 case PhysShapeCircle circle:
                     var center = Transform.Mul(xform, circle.Position);
                     worldHandle.DrawCircle(center, circle.Radius, color);
                     break;
                 case EdgeShape edge:
-                {
                     var v1 = Transform.Mul(xform, edge.Vertex1);
                     var v2 = Transform.Mul(xform, edge.Vertex2);
                     worldHandle.DrawLine(v1, v2, color);
@@ -494,7 +465,6 @@ namespace Robust.Client.Debugging
                         worldHandle.DrawCircle(v1, 0.1f, color);
                         worldHandle.DrawCircle(v2, 0.1f, color);
                     }
-                }
 
                     break;
                 case PolygonShape poly:

Robust.Client/GameController/GameController.RobustModules.cs

@@ -3,7 +3,6 @@ using System.IO;
 using System.Reflection;
 using System.Runtime.Loader;
 using Robust.Client.WebViewHook;
-using Robust.Shared.ContentPack;
 using Robust.Shared.Log;
 using Robust.Shared.Utility;
 

Robust.Client/GameController/GameController.cs

@@ -287,6 +287,78 @@ namespace Robust.Client
             return true;
         }
 
+        private ResourceManifestData LoadResourceManifest()
+        {
+            // Parses /manifest.yml for game-specific settings that cannot be exclusively set up by content code.
+            if (!_resourceCache.TryContentFileRead("/manifest.yml", out var stream))
+                return ResourceManifestData.Default;
+
+            var yamlStream = new YamlStream();
+            using (stream)
+            {
+                using var streamReader = new StreamReader(stream, EncodingHelpers.UTF8);
+                yamlStream.Load(streamReader);
+            }
+
+            if (yamlStream.Documents.Count == 0)
+                return ResourceManifestData.Default;
+
+            if (yamlStream.Documents.Count != 1 || yamlStream.Documents[0].RootNode is not YamlMappingNode mapping)
+            {
+                throw new InvalidOperationException(
+                    "Expected a single YAML document with root mapping for /manifest.yml");
+            }
+
+            var modules = ReadStringArray(mapping, "modules") ?? Array.Empty<string>();
+
+            string? assemblyPrefix = null;
+            if (mapping.TryGetNode("assemblyPrefix", out var prefixNode))
+                assemblyPrefix = prefixNode.AsString();
+
+            string? defaultWindowTitle = null;
+            if (mapping.TryGetNode("defaultWindowTitle", out var winTitleNode))
+                defaultWindowTitle = winTitleNode.AsString();
+
+            string? windowIconSet = null;
+            if (mapping.TryGetNode("windowIconSet", out var iconSetNode))
+                windowIconSet = iconSetNode.AsString();
+
+            string? splashLogo = null;
+            if (mapping.TryGetNode("splashLogo", out var splashNode))
+                splashLogo = splashNode.AsString();
+
+            bool autoConnect = true;
+            if (mapping.TryGetNode("autoConnect", out var autoConnectNode))
+                autoConnect = autoConnectNode.AsBool();
+
+            var clientAssemblies = ReadStringArray(mapping, "clientAssemblies");
+
+            return new ResourceManifestData(
+                modules,
+                assemblyPrefix,
+                defaultWindowTitle,
+                windowIconSet,
+                splashLogo,
+                autoConnect,
+                clientAssemblies
+            );
+
+            static string[]? ReadStringArray(YamlMappingNode mapping, string key)
+            {
+                if (!mapping.TryGetNode(key, out var node))
+                    return null;
+
+                var sequence = (YamlSequenceNode)node;
+                var array = new string[sequence.Children.Count];
+                for (var i = 0; i < array.Length; i++)
+                {
+                    array[i] = sequence[i].AsString();
+                }
+
+                return array;
+            }
+        }
+
         internal bool StartupSystemSplash(
             GameControllerOptions options,
             Func<ILogHandler>? logHandlerFactory,
@@ -385,7 +457,7 @@ namespace Robust.Client
                 _modLoader.VerifierExtraLoadHandler = VerifierExtraLoadHandler;
             }
 
-            _resourceManifest = ResourceManifestData.LoadResourceManifest(_resourceCache);
+            _resourceManifest = LoadResourceManifest();
 
             {
                 // Handle GameControllerOptions implicit CVar overrides.
@@ -632,6 +704,7 @@ namespace Robust.Client
             logManager.GetSawmill("ogl.debug.other").Level = LogLevel.Warning;
             logManager.GetSawmill("gdparse").Level = LogLevel.Error;
             logManager.GetSawmill("discord").Level = LogLevel.Warning;
+            logManager.GetSawmill("net.predict").Level = LogLevel.Info;
             logManager.GetSawmill("szr").Level = LogLevel.Info;
             logManager.GetSawmill("loc").Level = LogLevel.Warning;
 
@@ -713,6 +786,20 @@ namespace Robust.Client
             _clydeAudio.Shutdown();
         }
 
+        private sealed record ResourceManifestData(
+            string[] Modules,
+            string? AssemblyPrefix,
+            string? DefaultWindowTitle,
+            string? WindowIconSet,
+            string? SplashLogo,
+            bool AutoConnect,
+            string[]? ClientAssemblies
+        )
+        {
+            public static readonly ResourceManifestData Default =
+                new ResourceManifestData(Array.Empty<string>(), null, null, null, null, true, null);
+        }
+
         public event Action<FrameEventArgs>? TickUpdateOverride;
     }
 }

Robust.Client/GameObjects/ClientEntityManager.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using Prometheus;
 using Robust.Client.GameStates;
 using Robust.Client.Player;
@@ -85,17 +86,11 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
-        public override void Dirty(EntityUid uid, IComponent component, MetaDataComponent? meta = null)
-        {
-            Dirty(new Entity<IComponent>(uid, component), meta);
-        }
-
-        /// <inheritdoc />
-        public override void Dirty<T>(Entity<T> ent, MetaDataComponent? meta = null)
+        public override void Dirty(EntityUid uid, Component component, MetaDataComponent? meta = null)
         {
             //  Client only dirties during prediction
             if (_gameTiming.InPrediction)
-                base.Dirty(ent, meta);
+                base.Dirty(uid, component, meta);
         }
 
         public override EntityStringRepresentation ToPrettyString(EntityUid uid, MetaDataComponent? metaDataComponent = null)
@@ -170,7 +165,7 @@ namespace Robust.Client.GameObjects
         }
 
         /// <inheritdoc />
-        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel? channel)
+        public void SendSystemNetworkMessage(EntityEventArgs message, INetChannel channel)
         {
             throw new NotSupportedException();
         }

Robust.Client/GameObjects/Components/Animations/AnimationPlayerComponent.cs

@@ -1,6 +1,8 @@
+using System;
 using System.Collections.Generic;
 using Robust.Client.Animations;
 using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
 using static Robust.Client.Animations.AnimationPlaybackShared;
 
 namespace Robust.Client.GameObjects
@@ -19,5 +21,42 @@ namespace Robust.Client.GameObjects
             = new();
 
         internal bool HasPlayingAnimation = false;
+
+        /// <summary>
+        ///     Start playing an animation.
+        /// </summary>
+        /// <param name="animation">The animation to play.</param>
+        /// <param name="key">
+        ///     The key for this animation play. This key can be used to stop playback short later.
+        /// </param>
+        [Obsolete("Use AnimationPlayerSystem.Play() instead")]
+        public void Play(Animation animation, string key)
+        {
+            IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<AnimationPlayerSystem>().AddComponent(this);
+            var playback = new AnimationPlayback(animation);
+
+            PlayingAnimations.Add(key, playback);
+        }
+
+        [Obsolete("Use AnimationPlayerSystem.HasRunningAnimation() instead")]
+        public bool HasRunningAnimation(string key)
+        {
+            return PlayingAnimations.ContainsKey(key);
+        }
+
+        [Obsolete("Use AnimationPlayerSystem.Stop() instead")]
+        public void Stop(string key)
+        {
+            PlayingAnimations.Remove(key);
+        }
+
+        [Obsolete("Temporary method until the event is replaced with eventbus")]
+        internal void AnimationComplete(string key)
+        {
+            AnimationCompleted?.Invoke(key);
+        }
+
+        [Obsolete("Use AnimationCompletedEvent instead")]
+        public event Action<string>? AnimationCompleted;
     }
 }

Robust.Client/GameObjects/EntitySystems/AnimationPlayerSystem.cs

@@ -1,19 +1,22 @@
-using System;
 using System.Collections.Generic;
 using Robust.Client.Animations;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.GameObjects
 {
-    public sealed class AnimationPlayerSystem : EntitySystem
+    public sealed class AnimationPlayerSystem : EntitySystem, IPostInjectInit
     {
-        private readonly List<Entity<AnimationPlayerComponent>> _activeAnimations = new();
+        private readonly List<AnimationPlayerComponent> _activeAnimations = new();
 
         private EntityQuery<MetaDataComponent> _metaQuery;
 
         [Dependency] private readonly IComponentFactory _compFact = default!;
+        [Dependency] private readonly ILogManager _logManager = default!;
+
+        private ISawmill _sawmill = default!;
 
         public override void Initialize()
         {
@@ -35,22 +38,22 @@ namespace Robust.Client.GameObjects
                     continue;
                 }
 
-                if (!Update(uid, anim.Comp, frameTime))
+                if (!Update(uid, anim, frameTime))
                 {
                     continue;
                 }
 
                 _activeAnimations.RemoveSwap(i);
                 i--;
-                anim.Comp.HasPlayingAnimation = false;
+                anim.HasPlayingAnimation = false;
             }
         }
 
-        internal void AddComponent(Entity<AnimationPlayerComponent> ent)
+        internal void AddComponent(AnimationPlayerComponent component)
         {
-            if (ent.Comp.HasPlayingAnimation) return;
-            _activeAnimations.Add(ent);
-            ent.Comp.HasPlayingAnimation = true;
+            if (component.HasPlayingAnimation) return;
+            _activeAnimations.Add(component);
+            component.HasPlayingAnimation = true;
         }
 
         private bool Update(EntityUid uid, AnimationPlayerComponent component, float frameTime)
@@ -75,6 +78,7 @@ namespace Robust.Client.GameObjects
             {
                 component.PlayingAnimations.Remove(key);
                 EntityManager.EventBus.RaiseLocalEvent(uid, new AnimationCompletedEvent {Uid = uid, Key = key}, true);
+                component.AnimationComplete(key);
             }
 
             return false;
@@ -85,29 +89,22 @@ namespace Robust.Client.GameObjects
         /// </summary>
         public void Play(EntityUid uid, Animation animation, string key)
         {
-            var component = EnsureComp<AnimationPlayerComponent>(uid);
-            Play(new Entity<AnimationPlayerComponent>(uid, component), animation, key);
+            var component = EntityManager.EnsureComponent<AnimationPlayerComponent>(uid);
+            Play(component, animation, key);
         }
 
-        [Obsolete("Use Play(EntityUid<AnimationPlayerComponent> ent, Animation animation, string key) instead")]
         public void Play(EntityUid uid, AnimationPlayerComponent? component, Animation animation, string key)
         {
             component ??= EntityManager.EnsureComponent<AnimationPlayerComponent>(uid);
-            Play(new Entity<AnimationPlayerComponent>(uid, component), animation, key);
+            Play(component, animation, key);
         }
 
         /// <summary>
         ///     Start playing an animation.
         /// </summary>
-        [Obsolete("Use Play(EntityUid<AnimationPlayerComponent> ent, Animation animation, string key) instead")]
         public void Play(AnimationPlayerComponent component, Animation animation, string key)
         {
-            Play(new Entity<AnimationPlayerComponent>(component.Owner, component), animation, key);
-        }
-
-        public void Play(Entity<AnimationPlayerComponent> ent, Animation animation, string key)
-        {
-            AddComponent(ent);
+            AddComponent(component);
             var playback = new AnimationPlaybackShared.AnimationPlayback(animation);
 
 #if DEBUG
@@ -119,18 +116,18 @@ namespace Robust.Client.GameObjects
 
                 if (compTrack.ComponentType == null)
                 {
-                    Log.Error("Attempted to play a component animation without any component specified.");
+                    _sawmill.Error("Attempted to play a component animation without any component specified.");
                     return;
                 }
 
-                if (!EntityManager.TryGetComponent(ent, compTrack.ComponentType, out var animatedComp))
+                if (!EntityManager.TryGetComponent(component.Owner, compTrack.ComponentType, out var animatedComp))
                 {
-                    Log.Error(
-                        $"Attempted to play a component animation, but the entity {ToPrettyString(ent)} does not have the component to be animated: {compTrack.ComponentType}.");
+                    _sawmill.Error(
+                        $"Attempted to play a component animation, but the entity {ToPrettyString(component.Owner)} does not have the component to be animated: {compTrack.ComponentType}.");
                     return;
                 }
 
-                if (IsClientSide(ent) || !animatedComp.NetSyncEnabled)
+                if (IsClientSide(component.Owner) || !animatedComp.NetSyncEnabled)
                     continue;
 
                 var reg = _compFact.GetRegistration(animatedComp);
@@ -143,13 +140,13 @@ namespace Robust.Client.GameObjects
                     if (animatedComp.GetType().GetProperty(compTrack.Property) is { } property &&
                         property.HasCustomAttribute<AutoNetworkedFieldAttribute>())
                     {
-                        Log.Warning($"Playing a component animation on a networked component {reg.Name} belonging to {ToPrettyString(ent)}");
+                        _sawmill.Warning($"Playing a component animation on a networked component {reg.Name} belonging to {ToPrettyString(component.Owner)}");
                     }
                 }
             }
 #endif
 
-            ent.Comp.PlayingAnimations.Add(key, playback);
+            component.PlayingAnimations.Add(key, playback);
         }
 
         public bool HasRunningAnimation(EntityUid uid, string key)
@@ -178,19 +175,20 @@ namespace Robust.Client.GameObjects
 
         public void Stop(EntityUid uid, string key)
         {
-            if (!TryComp<AnimationPlayerComponent>(uid, out var player))
-                return;
-
+            if (!TryComp<AnimationPlayerComponent>(uid, out var player)) return;
             player.PlayingAnimations.Remove(key);
         }
 
         public void Stop(EntityUid uid, AnimationPlayerComponent? component, string key)
         {
-            if (!Resolve(uid, ref component, false))
-                return;
-
+            if (!Resolve(uid, ref component, false)) return;
             component.PlayingAnimations.Remove(key);
         }
+
+        void IPostInjectInit.PostInject()
+        {
+            _sawmill = _logManager.GetSawmill("anim");
+        }
     }
 
     public sealed class AnimationCompletedEvent : EntityEventArgs

Robust.Client/GameObjects/EntitySystems/AudioSystem.cs

@@ -17,6 +17,7 @@ using Robust.Shared.Physics;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Systems;
 using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Random;
 using Robust.Shared.Replays;
 using Robust.Shared.Threading;

Robust.Client/GameObjects/EntitySystems/EyeSystem.cs

@@ -1,7 +1,7 @@
 using Robust.Client.Graphics;
 using Robust.Client.Physics;
-using Robust.Client.Player;
 using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
 using Robust.Shared.Graphics;
 using Robust.Shared.IoC;
 
@@ -15,8 +15,8 @@ public sealed class EyeSystem : SharedEyeSystem
     {
         base.Initialize();
         SubscribeLocalEvent<EyeComponent, ComponentInit>(OnInit);
-        SubscribeLocalEvent<EyeComponent, LocalPlayerDetachedEvent>(OnEyeDetached);
-        SubscribeLocalEvent<EyeComponent, LocalPlayerAttachedEvent>(OnEyeAttached);
+        SubscribeLocalEvent<EyeComponent, PlayerDetachedEvent>(OnEyeDetached);
+        SubscribeLocalEvent<EyeComponent, PlayerAttachedEvent>(OnEyeAttached);
         SubscribeLocalEvent<EyeComponent, AfterAutoHandleStateEvent>(OnEyeAutoState);
 
         // Make sure this runs *after* entities have been moved by interpolation and movement.
@@ -29,7 +29,7 @@ public sealed class EyeSystem : SharedEyeSystem
         UpdateEye(component);
     }
 
-    private void OnEyeAttached(EntityUid uid, EyeComponent component, LocalPlayerAttachedEvent args)
+    private void OnEyeAttached(EntityUid uid, EyeComponent component, PlayerAttachedEvent args)
     {
         // TODO: This probably shouldn't be nullable bruv.
         if (component._eye != null)
@@ -41,7 +41,7 @@ public sealed class EyeSystem : SharedEyeSystem
         RaiseLocalEvent(uid, ref ev, true);
     }
 
-    private void OnEyeDetached(EntityUid uid, EyeComponent component, LocalPlayerDetachedEvent args)
+    private void OnEyeDetached(EntityUid uid, EyeComponent component, PlayerDetachedEvent args)
     {
         _eyeManager.ClearCurrentEye();
     }

Robust.Client/GameObjects/EntitySystems/GridChunkBoundsDebugSystem.cs

@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using System.Numerics;
 using Robust.Client.Graphics;
 using Robust.Shared.Enums;
@@ -59,8 +58,6 @@ namespace Robust.Client.GameObjects
 
         public override OverlaySpace Space => OverlaySpace.WorldSpace;
 
-        private List<Entity<MapGridComponent>> _grids = new();
-
         public GridChunkBoundsOverlay(IEntityManager entManager, IEyeManager eyeManager, IMapManager mapManager)
         {
             _entityManager = entManager;
@@ -74,15 +71,13 @@ namespace Robust.Client.GameObjects
             var viewport = args.WorldBounds;
             var worldHandle = args.WorldHandle;
 
-            _grids.Clear();
-            _mapManager.FindGridsIntersecting(currentMap, viewport, ref _grids);
-            foreach (var grid in _grids)
+            foreach (var grid in _mapManager.FindGridsIntersecting(currentMap, viewport))
             {
-                var worldMatrix = _entityManager.GetComponent<TransformComponent>(grid).WorldMatrix;
+                var worldMatrix = _entityManager.GetComponent<TransformComponent>(grid.Owner).WorldMatrix;
                 worldHandle.SetTransform(worldMatrix);
                 var transform = new Transform(Vector2.Zero, Angle.Zero);
 
-                var chunkEnumerator = grid.Comp.GetMapChunks(viewport);
+                var chunkEnumerator = grid.GetMapChunks(viewport);
 
                 while (chunkEnumerator.MoveNext(out var chunk))
                 {

Robust.Client/GameObjects/EntitySystems/InputSystem.cs

@@ -3,13 +3,16 @@ using System.Numerics;
 using Robust.Client.GameStates;
 using Robust.Client.Input;
 using Robust.Client.Player;
+using Robust.Shared;
+using Robust.Shared.Configuration;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
-using Robust.Shared.Player;
+using Robust.Shared.Maths;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -128,7 +131,7 @@ namespace Robust.Client.GameObjects
 
         public override void Initialize()
         {
-            SubscribeLocalEvent<LocalPlayerAttachedEvent>(OnAttachedEntityChanged);
+            SubscribeLocalEvent<PlayerAttachSysMessage>(OnAttachedEntityChanged);
 
             _conHost.RegisterCommand("incmd",
                 "Inserts an input command into the simulation",
@@ -168,11 +171,11 @@ namespace Robust.Client.GameObjects
             HandleInputCommand(localPlayer.Session, keyFunction, message);
         }
 
-        private void OnAttachedEntityChanged(LocalPlayerAttachedEvent message)
+        private void OnAttachedEntityChanged(PlayerAttachSysMessage message)
         {
-            if (message.Entity != default) // attach
+            if (message.AttachedEntity != default) // attach
             {
-                SetEntityContextActive(_inputManager, message.Entity);
+                SetEntityContextActive(_inputManager, message.AttachedEntity);
             }
             else // detach
             {
@@ -224,4 +227,44 @@ namespace Robust.Client.GameObjects
             _sawmillInputContext = _logManager.GetSawmill("input.context");
         }
     }
+
+    /// <summary>
+    ///     Entity system message that is raised when the player changes attached entities.
+    /// </summary>
+    public sealed class PlayerAttachSysMessage : EntityEventArgs
+    {
+        /// <summary>
+        ///     New entity the player is attached to.
+        /// </summary>
+        public EntityUid AttachedEntity { get; }
+
+        /// <summary>
+        ///     Creates a new instance of <see cref="PlayerAttachSysMessage"/>.
+        /// </summary>
+        /// <param name="attachedEntity">New entity the player is attached to.</param>
+        public PlayerAttachSysMessage(EntityUid attachedEntity)
+        {
+            AttachedEntity = attachedEntity;
+        }
+    }
+
+    public sealed class PlayerAttachedEvent : EntityEventArgs
+    {
+        public PlayerAttachedEvent(EntityUid entity)
+        {
+            Entity = entity;
+        }
+
+        public EntityUid Entity { get; }
+    }
+
+    public sealed class PlayerDetachedEvent : EntityEventArgs
+    {
+        public PlayerDetachedEvent(EntityUid entity)
+        {
+            Entity = entity;
+        }
+
+        public EntityUid Entity { get; }
+    }
 }

Robust.Client/GameObjects/EntitySystems/SpriteSystem.cs

@@ -1,16 +1,13 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Numerics;
 using JetBrains.Annotations;
 using Robust.Client.ComponentTrees;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
-using Robust.Client.Utility;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Graphics.RSI;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
@@ -18,7 +15,6 @@ using Robust.Shared.Maths;
 using Robust.Shared.Physics;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Timing;
-using Robust.Shared.Utility;
 using static Robust.Client.GameObjects.SpriteComponent;
 
 namespace Robust.Client.GameObjects
@@ -187,48 +183,6 @@ namespace Robust.Client.GameObjects
         {
             _queuedFrameUpdate.Add(uid);
         }
-
-        /// <summary>
-        /// Gets the specified frame for this sprite at the specified time.
-        /// </summary>
-        public Texture GetFrame(SpriteSpecifier spriteSpec, TimeSpan curTime)
-        {
-            Texture? sprite = null;
-
-            switch (spriteSpec)
-            {
-                case SpriteSpecifier.Rsi rsi:
-                    var rsiActual = _resourceCache.GetResource<RSIResource>(rsi.RsiPath).RSI;
-                    rsiActual.TryGetState(rsi.RsiState, out var state);
-                    var frames = state!.GetFrames(RsiDirection.South);
-                    var delays = state.GetDelays();
-                    var totalDelay = delays.Sum();
-                    var time = curTime.TotalSeconds % totalDelay;
-                    var delaySum = 0f;
-
-                    for (var i = 0; i < delays.Length; i++)
-                    {
-                        var delay = delays[i];
-                        delaySum += delay;
-
-                        if (time > delaySum)
-                            continue;
-
-                        sprite = frames[i];
-                        break;
-                    }
-
-                    sprite ??= Frame0(spriteSpec);
-                    break;
-                case SpriteSpecifier.Texture texture:
-                    sprite = texture.GetTexture(_resourceCache);
-                    break;
-                default:
-                    throw new NotImplementedException();
-            }
-
-            return sprite;
-        }
     }
 
     /// <summary>

Robust.Client/GameObjects/EntitySystems/TransformSystem.cs

@@ -28,11 +28,11 @@ namespace Robust.Client.GameObjects
 
         // Only keep track of transforms actively lerping.
         // Much faster than iterating 3000+ transforms every frame.
-        [ViewVariables] private readonly List<Entity<TransformComponent>> _lerpingTransforms = new();
+        [ViewVariables] private readonly List<TransformComponent> _lerpingTransforms = new();
 
         public void Reset()
         {
-            foreach (var (_, xform) in _lerpingTransforms)
+            foreach (var xform in _lerpingTransforms)
             {
                 xform.ActivelyLerping = false;
                 xform.NextPosition = null;
@@ -54,10 +54,9 @@ namespace Robust.Client.GameObjects
             //   should show the entity lerping.
             // - If the client predicts an entity will move while already lerping due to a state-application, it should
             //   clear the state's lerp, under the assumption that the client predicted the state and already rendered
-            //   the entity in the state's final position.
+            //   the entity in the final position.
             // - If the client predicts that an entity moves, then we only lerp if this is the first time that the tick
-            //   was predicted. I.e., we assume the entity was already rendered in the final position that was
-            //   previously predicted.
+            //   was predicted. I.e., we assume the entity was already rendered in it's final of that lerp.
             // - If the client predicts that an entity should lerp twice in the same tick, then we need to combine them.
             //   I.e. moving from a->b then b->c, the client should lerp from a->c.
 
@@ -78,7 +77,7 @@ namespace Robust.Client.GameObjects
                     return;
                 }
 
-                _lerpingTransforms.Add((uid, xform));
+                _lerpingTransforms.Add(xform);
                 xform.ActivelyLerping = true;
                 xform.PredictedLerp = false;
                 xform.LerpParent = xform.ParentUid;
@@ -97,7 +96,7 @@ namespace Robust.Client.GameObjects
 
             if (!xform.ActivelyLerping)
             {
-                _lerpingTransforms.Add((uid, xform));
+                _lerpingTransforms.Add(xform);
                 xform.ActivelyLerping = true;
                 xform.PredictedLerp = true;
                 xform.PrevRotation = xform._localRotation;
@@ -124,7 +123,8 @@ namespace Robust.Client.GameObjects
 
             for (var i = 0; i < _lerpingTransforms.Count; i++)
             {
-                var (uid, transform) = _lerpingTransforms[i];
+                var transform = _lerpingTransforms[i];
+                var uid = transform.Owner;
                 var found = false;
 
                 // Only lerp if parent didn't change.

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -26,6 +26,8 @@ using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Components;
 using Robust.Shared.Profiling;
 using Robust.Shared.Replays;
 using Robust.Shared.Timing;
@@ -35,7 +37,7 @@ namespace Robust.Client.GameStates
 {
     /// <inheritdoc />
     [UsedImplicitly]
-    public sealed class ClientGameStateManager : IClientGameStateManager
+    public sealed class ClientGameStateManager : IClientGameStateManager, IPostInjectInit
     {
         private GameStateProcessor _processor = default!;
 
@@ -53,7 +55,7 @@ namespace Robust.Client.GameStates
         private readonly Dictionary<EntityUid, HashSet<Type>> _pendingReapplyNetStates = new();
         private readonly HashSet<NetEntity> _stateEnts = new();
         private readonly List<EntityUid> _toDelete = new();
-        private readonly List<IComponent> _toRemove = new();
+        private readonly List<Component> _toRemove = new();
         private readonly Dictionary<NetEntity, Dictionary<ushort, ComponentState>> _outputData = new();
         private readonly List<(EntityUid, TransformComponent)> _queuedBroadphaseUpdates = new();
 
@@ -80,13 +82,6 @@ namespace Robust.Client.GameStates
 
         private ISawmill _sawmill = default!;
 
-        /// <summary>
-        /// If we are waiting for a full game state from the server, we will automatically re-send full state requests
-        /// if they do not arrive in time. Ideally this should never happen, this here just in case a client gets
-        /// stuck waiting for a full state that the server doesn't know the client even wants.
-        /// </summary>
-        public static readonly TimeSpan FullStateTimeout = TimeSpan.FromSeconds(10);
-
         /// <inheritdoc />
         public int MinBufferSize => _processor.MinBufferSize;
 
@@ -94,8 +89,7 @@ namespace Robust.Client.GameStates
         public int TargetBufferSize => _processor.TargetBufferSize;
 
         /// <inheritdoc />
-        public int GetApplicableStateCount() => _processor.GetApplicableStateCount();
-        public int StateCount => _processor.StateCount;
+        public int CurrentBufferSize => _processor.CalculateBufferSize(_timing.LastRealTick);
 
         public bool IsPredictionEnabled { get; private set; }
         public bool PredictionNeedsResetting { get; private set; }
@@ -127,10 +121,7 @@ namespace Robust.Client.GameStates
         /// <inheritdoc />
         public void Initialize()
         {
-            _sawmill = _logMan.GetSawmill("state");
-            _sawmill.Level = LogLevel.Info;
-
-            _processor = new GameStateProcessor(this, _timing, _sawmill);
+            _processor = new GameStateProcessor(_timing);
 
             _network.RegisterNetMessage<MsgState>(HandleStateMessage);
             _network.RegisterNetMessage<MsgStateLeavePvs>(HandlePvsLeaveMessage);
@@ -146,7 +137,6 @@ namespace Robust.Client.GameStates
             _config.OnValueChanged(CVars.NetPredictLagBias, i => PredictLagBias = i, true);
             _config.OnValueChanged(CVars.NetStateBufMergeThreshold, i => StateBufferMergeThreshold = i, true);
             _config.OnValueChanged(CVars.NetPVSEntityExitBudget, i => _pvsDetachBudget = i, true);
-            _config.OnValueChanged(CVars.NetMaxBufferSize, i => _processor.MaxBufferSize = i, true);
 
             _processor.Interpolation = _config.GetCVar(CVars.NetInterp);
             _processor.BufferSize = _config.GetCVar(CVars.NetBufferSize);
@@ -255,19 +245,9 @@ namespace Robust.Client.GameStates
         /// <inheritdoc />
         public void ApplyGameState()
         {
-            // If we have been waiting for a full state for a long time, re-request a full state.
-            if (_processor.WaitingForFull
-                && _processor.LastFullStateRequested is {} last
-                && DateTime.UtcNow - last.Time > FullStateTimeout)
-            {
-                // Re-request a full state.
-                // We use the previous from-tick, just in case the full state is already on the way,
-                RequestFullState(null, last.Tick);
-            }
-
             // Calculate how many states we need to apply this tick.
             // Always at least one, but can be more based on StateBufferMergeThreshold.
-            var curBufSize = GetApplicableStateCount();
+            var curBufSize = CurrentBufferSize;
             var targetBufSize = TargetBufferSize;
 
             var bufferOverflow = curBufSize - targetBufSize - StateBufferMergeThreshold;
@@ -320,9 +300,9 @@ namespace Robust.Client.GameStates
                 }
 
                 // If we were waiting for a new state, we are now applying it.
-                if (_processor.WaitingForFull)
+                if (_processor.LastFullStateRequested.HasValue)
                 {
-                    _processor.OnFullStateReceived();
+                    _processor.LastFullStateRequested = null;
                     _timing.LastProcessedTick = curState.ToSequence;
                     DebugTools.Assert(curState.FromSequence == GameTick.Zero);
                     PartialStateReset(curState, true);
@@ -387,7 +367,7 @@ namespace Robust.Client.GameStates
             if (_processor.WaitingForFull)
                 _timing.TickTimingAdjustment = 0f;
             else
-                _timing.TickTimingAdjustment = (GetApplicableStateCount() - (float)TargetBufferSize) * 0.10f;
+                _timing.TickTimingAdjustment = (CurrentBufferSize - (float)TargetBufferSize) * 0.10f;
 
             // If we are about to process an another tick in the same frame, lets not bother unnecessarily running prediction ticks
             // Really the main-loop ticking just needs to be more specialized for clients.
@@ -432,11 +412,11 @@ namespace Robust.Client.GameStates
             }
         }
 
-        public void RequestFullState(NetEntity? missingEntity = null, GameTick? tick = null)
+        public void RequestFullState(NetEntity? missingEntity = null)
         {
             _sawmill.Info("Requesting full server state");
             _network.ClientSendMessage(new MsgStateRequestFull { Tick = _timing.LastRealTick , MissingEntity = missingEntity ?? NetEntity.Invalid });
-            _processor.OnFullStateRequested(tick ?? _timing.LastRealTick);
+            _processor.RequestFullState();
         }
 
         public void PredictTicks(GameTick predictionTarget)
@@ -519,7 +499,7 @@ namespace Robust.Client.GameStates
             var countReset = 0;
             var system = _entitySystemManager.GetEntitySystem<ClientDirtySystem>();
             var metaQuery = _entityManager.GetEntityQuery<MetaDataComponent>();
-            RemQueue<IComponent> toRemove = new();
+            RemQueue<Component> toRemove = new();
 
             foreach (var entity in system.DirtyEntities)
             {
@@ -624,7 +604,7 @@ namespace Robust.Client.GameStates
         ///     Whenever a new entity is created, the server doesn't send full state data, given that much of the data
         ///     can simply be obtained from the entity prototype information. This function basically creates a fake
         ///     initial server state for any newly created entity. It does this by simply using the standard <see
-        ///     cref="IEntityManager.GetComponentState"/>.
+        ///     cref="IEntityManager.GetComponentState(IEventBus, IComponent)"/>.
         /// </remarks>
         private void MergeImplicitData(IEnumerable<NetEntity> createdEntities)
         {
@@ -690,7 +670,7 @@ namespace Robust.Client.GameStates
 
             using (_prof.Group("Player"))
             {
-                _players.ApplyPlayerStates(curState.PlayerStates.Value ?? Array.Empty<SessionState>());
+                _players.ApplyPlayerStates(curState.PlayerStates.Value ?? Array.Empty<PlayerState>());
             }
 
             using (_prof.Group("Callback"))
@@ -1207,7 +1187,8 @@ namespace Robust.Client.GameStates
                 {
                     if (!meta.NetComponents.TryGetValue(id, out var comp))
                     {
-                        comp = _compFactory.GetComponent(id);
+                        comp = (Component) _compFactory.GetComponent(id);
+                        comp.Owner = uid;
                         _entityManager.AddComponent(uid, comp, true, metadata: meta);
                     }
 
@@ -1220,7 +1201,8 @@ namespace Robust.Client.GameStates
                 {
                     if (!meta.NetComponents.TryGetValue(compChange.NetID, out var comp))
                     {
-                        comp = _compFactory.GetComponent(compChange.NetID);
+                        comp = (Component) _compFactory.GetComponent(compChange.NetID);
+                        comp.Owner = uid;
                         _entityManager.AddComponent(uid, comp, true, metadata:meta);
                     }
                     else if (compChange.LastModifiedTick <= lastApplied && lastApplied != GameTick.Zero)
@@ -1290,9 +1272,7 @@ namespace Robust.Client.GameStates
                     var handleState = new ComponentHandleState(cur, next);
                     bus.RaiseComponentEvent(comp, ref handleState);
                 }
-#pragma warning disable CS0168 // Variable is declared but never used
                 catch (Exception e)
-#pragma warning restore CS0168 // Variable is declared but never used
                 {
 #if EXCEPTION_TOLERANCE
                     _sawmill.Error($"Failed to apply comp state: entity={_entities.ToPrettyString(uid)}, comp={comp.GetType()}");
@@ -1448,7 +1428,8 @@ namespace Robust.Client.GameStates
             {
                 if (!meta.NetComponents.TryGetValue(id, out var comp))
                 {
-                    comp = _compFactory.GetComponent(id);
+                    comp = (Component) _compFactory.GetComponent(id);
+                    comp.Owner = uid;
                     _entityManager.AddComponent(uid, comp, true, meta);
                 }
 
@@ -1474,6 +1455,11 @@ namespace Robust.Client.GameStates
 
         public bool IsQueuedForDetach(NetEntity entity)
             => _processor.IsQueuedForDetach(entity);
+
+        void IPostInjectInit.PostInject()
+        {
+            _sawmill = _logMan.GetSawmill(CVars.NetPredict.Name);
+        }
     }
 
     public sealed class GameStateAppliedArgs : EventArgs

Robust.Client/GameStates/GameStateProcessor.cs

@@ -1,33 +1,46 @@
-using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 using Robust.Client.Timing;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
+using Robust.Shared.IoC;
 using Robust.Shared.Log;
+using Robust.Shared.Network.Messages;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
 namespace Robust.Client.GameStates
 {
     /// <inheritdoc />
-    internal sealed class GameStateProcessor : IGameStateProcessor
+    internal sealed class GameStateProcessor : IGameStateProcessor, IPostInjectInit
     {
+        [Dependency] private ILogManager _logMan = default!;
+
         private readonly IClientGameTiming _timing;
-        private readonly IClientGameStateManager _state;
-        private readonly ISawmill _logger;
 
         private readonly List<GameState> _stateBuffer = new();
 
         private readonly Dictionary<GameTick, List<NetEntity>> _pvsDetachMessages = new();
+
+        private ISawmill _logger = default!;
+        private ISawmill _stateLogger = default!;
+
         public GameState? LastFullState { get; private set; }
         public bool WaitingForFull => LastFullStateRequested.HasValue;
-        public (GameTick Tick, DateTime Time)? LastFullStateRequested { get; private set; } = (GameTick.Zero, DateTime.MaxValue);
+        public GameTick? LastFullStateRequested
+        {
+            get => _lastFullStateRequested;
+            set
+            {
+                _lastFullStateRequested = value;
+                LastFullState = null;
+            }
+        }
+
+        public GameTick? _lastFullStateRequested = GameTick.Zero;
 
         private int _bufferSize;
-        private int _maxBufferSize = 512;
-        public const int MinimumMaxBufferSize = 256;
 
         /// <summary>
         /// This dictionary stores the full most recently received server state of any entity. This is used whenever predicted entities get reset.
@@ -48,14 +61,7 @@ namespace Robust.Client.GameStates
         public int BufferSize
         {
             get => _bufferSize;
-            set => _bufferSize = Math.Max(value, 0);
-        }
-
-        public int MaxBufferSize
-        {
-            get => _maxBufferSize;
-            // We place a lower bound on the maximum size to avoid spamming servers with full game state requests.
-            set => _maxBufferSize = Math.Max(value, MinimumMaxBufferSize);
+            set => _bufferSize = value < 0 ? 0 : value;
         }
 
         /// <inheritdoc />
@@ -65,12 +71,9 @@ namespace Robust.Client.GameStates
         ///     Constructs a new instance of <see cref="GameStateProcessor"/>.
         /// </summary>
         /// <param name="timing">Timing information of the current state.</param>
-        /// <param name="clientGameStateManager"></param>
-        public GameStateProcessor(IClientGameStateManager state, IClientGameTiming timing, ISawmill logger)
+        public GameStateProcessor(IClientGameTiming timing)
         {
             _timing = timing;
-            _state = state;
-            _logger = logger;
         }
 
         /// <inheritdoc />
@@ -80,7 +83,7 @@ namespace Robust.Client.GameStates
             if (state.ToSequence <= _timing.LastRealTick)
             {
                 if (Logging)
-                    _logger.Debug($"Received Old GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _stateLogger.Debug($"Received Old GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
 
                 return false;
             }
@@ -92,7 +95,7 @@ namespace Robust.Client.GameStates
                     continue;
 
                 if (Logging)
-                    _logger.Debug($"Received Dupe GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _stateLogger.Debug($"Received Dupe GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
 
                 return false;
             }
@@ -101,68 +104,34 @@ namespace Robust.Client.GameStates
             if (!WaitingForFull)
             {
                 // This is a good state that we will be using.
-                TryAdd(state);
+                _stateBuffer.Add(state);
                 if (Logging)
-                    _logger.Debug($"Received New GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
+                    _stateLogger.Debug($"Received New GameState: lastRealTick={_timing.LastRealTick}, fSeq={state.FromSequence}, tSeq={state.ToSequence}, sz={state.PayloadSize}, buf={_stateBuffer.Count}");
                 return true;
             }
 
-            if (LastFullState == null && state.FromSequence == GameTick.Zero)
+            if (LastFullState == null && state.FromSequence == GameTick.Zero && state.ToSequence >= LastFullStateRequested!.Value)
             {
-                if (state.ToSequence >= LastFullStateRequested!.Value.Tick)
-                {
-                    LastFullState = state;
-                    _logger.Info($"Received Full GameState: to={state.ToSequence}, sz={state.PayloadSize}");
-                    return true;
-                }
+                LastFullState = state;
 
-                _logger.Info($"Received a late full game state. Received: {state.ToSequence}. Requested: {LastFullStateRequested.Value.Tick}");
+                if (Logging)
+                    _logger.Info($"Received Full GameState: to={state.ToSequence}, sz={state.PayloadSize}");
+
+                return true;
             }
 
             if (LastFullState != null && state.ToSequence <= LastFullState.ToSequence)
             {
-                _logger.Info($"While waiting for full, received late GameState with lower to={state.ToSequence} than the last full state={LastFullState.ToSequence}");
+                if (Logging)
+                    _logger.Info($"While waiting for full, received late GameState with lower to={state.ToSequence} than the last full state={LastFullState.ToSequence}");
+
                 return false;
             }
 
-            TryAdd(state);
+            _stateBuffer.Add(state);
             return true;
         }
 
-        public void TryAdd(GameState state)
-        {
-            if (_stateBuffer.Count <= MaxBufferSize)
-            {
-                _stateBuffer.Add(state);
-                return;
-            }
-
-            // This can happen if a required state gets dropped somehow and the client keeps receiving future
-            // game states that they can't apply. I.e., GetApplicableStateCount() is zero, even though there are many
-            // states in the list.
-            //
-            // This can seemingly happen when the server sends ""reliable"" game states while the client is paused?
-            // For example, when debugging the client, while the server is running:
-            // - The client stops sending acks for states that the server sends out.
-            // - Thus the client will exceed the net.force_ack_threshold cvar
-            // - The server starts sending some packets ""reliably"" and just force updates the clients last ack.
-            //
-            // What should happen is that when the client resumes, it receives the reliably sent states and can just
-            // resume. However, even though the packets are sent ""reliably"", they just seem to get dropped.
-            // I don't quite understand how/why yet, but this ensures the client doesn't get stuck.
-#if FULL_RELEASE
-            _logger.Warning(@$"Exceeded maximum state buffer size!
-Tick: {_timing.CurTick}/{_timing.LastProcessedTick}/{_timing.LastRealTick}
-Size: {_stateBuffer.Count}
-Applicable states: {GetApplicableStateCount()}
-Was waiting for full: {WaitingForFull} {LastFullStateRequested}
-Had full state: {LastFullState != null}"
-            );
-#endif
-
-            _state.RequestFullState();
-        }
-
         /// <summary>
         ///     Attempts to get the current and next states to apply.
         /// </summary>
@@ -183,7 +152,7 @@ Had full state: {LastFullState != null}"
                     "Tried to apply a non-extrapolated state that has too high of a FromSequence!");
 
                 if (Logging)
-                    _logger.Debug($"Applying State:  cTick={_timing.LastProcessedTick}, fSeq={curState.FromSequence}, tSeq={curState.ToSequence}, buf={_stateBuffer.Count}");
+                    _stateLogger.Debug($"Applying State:  cTick={_timing.LastProcessedTick}, fSeq={curState.FromSequence}, tSeq={curState.ToSequence}, buf={_stateBuffer.Count}");
             }
 
             return applyNextState;
@@ -375,20 +344,14 @@ Had full state: {LastFullState != null}"
         {
             _stateBuffer.Clear();
             LastFullState = null;
-            LastFullStateRequested = (GameTick.Zero, DateTime.MaxValue);
+            LastFullStateRequested = GameTick.Zero;
         }
 
-        public void OnFullStateRequested(GameTick tick)
+        public void RequestFullState()
         {
             _stateBuffer.Clear();
             LastFullState = null;
-            LastFullStateRequested = (tick, DateTime.UtcNow);
-        }
-
-        public void OnFullStateReceived()
-        {
-            LastFullState = null;
-            LastFullStateRequested = null;
+            LastFullStateRequested = _timing.LastRealTick;
         }
 
         public void MergeImplicitData(Dictionary<NetEntity, Dictionary<ushort, ComponentState>> implicitData)
@@ -453,11 +416,10 @@ Had full state: {LastFullState != null}"
             return false;
         }
 
-        public int GetApplicableStateCount(GameTick? fromTick = null)
+        public int CalculateBufferSize(GameTick fromTick)
         {
-            fromTick ??= _timing.LastRealTick;
             bool foundState;
-            var nextTick = fromTick.Value;
+            var nextTick = fromTick;
 
             do
             {
@@ -475,9 +437,13 @@ Had full state: {LastFullState != null}"
             }
             while (foundState);
 
-            return (int) (nextTick.Value - fromTick.Value.Value);
+            return (int) (nextTick.Value - fromTick.Value);
         }
 
-        public int StateCount => _stateBuffer.Count;
+        void IPostInjectInit.PostInject()
+        {
+            _logger = _logMan.GetSawmill("net");
+            _stateLogger = _logMan.GetSawmill("net.state");
+        }
     }
 }

Robust.Client/GameStates/IClientGameStateManager.cs

@@ -32,15 +32,7 @@ namespace Robust.Client.GameStates
         /// <summary>
         ///     Number of applicable game states currently in the state buffer.
         /// </summary>
-        int GetApplicableStateCount();
-
-        [Obsolete("use GetApplicableStateCount()")]
-        int CurrentBufferSize => GetApplicableStateCount();
-
-        /// <summary>
-        ///     Total number of game states currently in the state buffer.
-        /// </summary>
-        int StateCount { get; }
+        int CurrentBufferSize { get; }
 
         /// <summary>
         ///     If the buffer size is this many states larger than the target buffer size,
@@ -99,7 +91,7 @@ namespace Robust.Client.GameStates
         /// <summary>
         ///     Requests a full state from the server. This should override even implicit entity data.
         /// </summary>
-        void RequestFullState(NetEntity? missingEntity = null, GameTick? tick = null);
+        void RequestFullState(NetEntity? missingEntity = null);
 
         uint SystemMessageDispatched<T>(T message) where T : EntityEventArgs;
 

Robust.Client/GameStates/IGameStateProcessor.cs

@@ -96,7 +96,7 @@ namespace Robust.Client.GameStates
         ///     This includes only applicable states. If there is a gap, future buffers are not included.
         /// </summary>
         /// <param name="fromTick">The tick to calculate from.</param>
-        int GetApplicableStateCount(GameTick? fromTick);
+        int CalculateBufferSize(GameTick fromTick);
 
         bool TryGetLastServerStates(NetEntity entity,
             [NotNullWhen(true)] out Dictionary<ushort, ComponentState>? dictionary);

Robust.Client/GameStates/NetGraphOverlay.cs

@@ -68,7 +68,7 @@ namespace Robust.Client.GameStates
             var lag = _netManager.ServerChannel!.Ping;
 
             // calc interp info
-            var buffer = _gameStateManager.GetApplicableStateCount();
+            var buffer = _gameStateManager.CurrentBufferSize;
 
             _totalHistoryPayload += sz;
             _history.Add((toSeq, sz, lag, buffer));
@@ -268,7 +268,7 @@ namespace Robust.Client.GameStates
                 handle.DrawString(_font, new Vector2(LeftMargin + width, lastLagY), $"{lastLagMs.ToString()}ms");
 
             // buffer text
-            handle.DrawString(_font, new Vector2(LeftMargin, height + LowerGraphOffset), $"{_gameStateManager.GetApplicableStateCount().ToString()} states");
+            handle.DrawString(_font, new Vector2(LeftMargin, height + LowerGraphOffset), $"{_gameStateManager.CurrentBufferSize.ToString()} states");
         }
 
         protected override void DisposeBehavior()

Robust.Client/Graphics/Clyde/Clyde.GridRendering.cs

@@ -4,6 +4,7 @@ using OpenToolkit.Graphics.OpenGL4;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Graphics;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
@@ -40,28 +41,22 @@ namespace Robust.Client.Graphics.Clyde
             gridProgram.SetUniformTextureMaybe(UniILightTexture, TextureUnit.Texture1);
             gridProgram.SetUniform(UniIModUV, new Vector4(0, 0, 1, 1));
 
-            var grids = new List<Entity<MapGridComponent>>();
-            _mapManager.FindGridsIntersecting(mapId, worldBounds, ref grids);
-            foreach (var mapGrid in grids)
+            foreach (var mapGrid in _mapManager.FindGridsIntersecting(mapId, worldBounds))
             {
-                if (!_mapChunkData.ContainsKey(mapGrid))
+                if (!_mapChunkData.ContainsKey(mapGrid.Owner))
                     continue;
 
-                var transform = _entityManager.GetComponent<TransformComponent>(mapGrid);
+                var transform = _entityManager.GetComponent<TransformComponent>(mapGrid.Owner);
                 gridProgram.SetUniform(UniIModelMatrix, transform.WorldMatrix);
-                var enumerator = mapGrid.Comp.GetMapChunks(worldBounds);
-                var data = _mapChunkData[mapGrid];
+                var enumerator = mapGrid.GetMapChunks(worldBounds);
 
                 while (enumerator.MoveNext(out var chunk))
                 {
-                    DebugTools.Assert(chunk.FilledTiles > 0);
-                    if (!data.TryGetValue(chunk.Indices, out MapChunkData? datum))
-                        data[chunk.Indices] = datum = _initChunkBuffers(mapGrid, chunk);
+                    if (_isChunkDirty(mapGrid, chunk))
+                        _updateChunkMesh(mapGrid, chunk);
 
-                    if (datum.Dirty)
-                        _updateChunkMesh(mapGrid, chunk, datum);
+                    var datum = _mapChunkData[mapGrid.Owner][chunk.Indices];
 
-                    DebugTools.Assert(datum.TileCount > 0);
                     if (datum.TileCount == 0)
                         continue;
 
@@ -73,36 +68,22 @@ namespace Robust.Client.Graphics.Clyde
                     CheckGlError();
                 }
             }
-
-            CullEmptyChunks();
         }
 
-        private void CullEmptyChunks()
+        private void _updateChunkMesh(MapGridComponent grid, MapChunk chunk)
         {
-            foreach (var (grid, chunks) in _mapChunkData)
+            var data = _mapChunkData[grid.Owner];
+
+            if (!data.TryGetValue(chunk.Indices, out var datum))
             {
-                var gridComp = _mapManager.GetGridComp(grid);
-                foreach (var (index, chunk) in chunks)
-                {
-                    if (!chunk.Dirty || gridComp.Chunks.ContainsKey(index))
-                    {
-                        DebugTools.Assert(gridComp.Chunks[index].FilledTiles > 0);
-                        continue;
-                    }
-
-                    DeleteChunk(chunk);
-                    chunks.Remove(index);
-                }
+                datum = _initChunkBuffers(grid, chunk);
             }
-        }
 
-        private void _updateChunkMesh(Entity<MapGridComponent> grid, MapChunk chunk, MapChunkData datum)
-        {
             Span<ushort> indexBuffer = stackalloc ushort[_indicesPerChunk(chunk)];
             Span<Vertex2D> vertexBuffer = stackalloc Vertex2D[_verticesPerChunk(chunk)];
 
             var i = 0;
-            var cSz = grid.Comp.ChunkSize;
+            var cSz = grid.ChunkSize;
             var cScaled = chunk.Indices * cSz;
             for (ushort x = 0; x < cSz; x++)
             {
@@ -149,7 +130,7 @@ namespace Robust.Client.Graphics.Clyde
             datum.TileCount = i;
         }
 
-        private unsafe MapChunkData _initChunkBuffers(Entity<MapGridComponent> grid, MapChunk chunk)
+        private unsafe MapChunkData _initChunkBuffers(MapGridComponent grid, MapChunk chunk)
         {
             var vao = GenVertexArray();
             BindVertexArray(vao);
@@ -177,22 +158,41 @@ namespace Robust.Client.Graphics.Clyde
                 Dirty = true
             };
 
+            _mapChunkData[grid.Owner].Add(chunk.Indices, datum);
             return datum;
         }
 
-        private void DeleteChunk(MapChunkData data)
+        private bool _isChunkDirty(MapGridComponent grid, MapChunk chunk)
         {
-            DeleteVertexArray(data.VAO);
-            CheckGlError();
-            data.VBO.Delete();
-            data.EBO.Delete();
+            var data = _mapChunkData[grid.Owner];
+            return !data.TryGetValue(chunk.Indices, out var datum) || datum.Dirty;
+        }
+
+        public void _setChunkDirty(MapGridComponent grid, Vector2i chunk)
+        {
+            var data = _mapChunkData.GetOrNew(grid.Owner);
+            if (data.TryGetValue(chunk, out var datum))
+            {
+                datum.Dirty = true;
+            }
+            // Don't need to set it if we don't have an entry since lack of an entry is treated as dirty.
+        }
+
+        private void _updateOnGridModified(GridModifiedEvent args)
+        {
+            foreach (var (pos, _) in args.Modified)
+            {
+                var grid = args.Grid;
+                var chunk = grid.GridTileToChunkIndices(pos);
+                _setChunkDirty(grid, chunk);
+            }
         }
 
         private void _updateTileMapOnUpdate(ref TileChangedEvent args)
         {
-            var gridData = _mapChunkData.GetOrNew(args.Entity);
-            if (gridData.TryGetValue(args.ChunkIndex, out var data))
-                data.Dirty = true;
+            var grid = _mapManager.GetGrid(args.NewTile.GridUid);
+            var chunk = grid.GridTileToChunkIndices(new Vector2i(args.NewTile.X, args.NewTile.Y));
+            _setChunkDirty(grid, chunk);
         }
 
         private void _updateOnGridCreated(GridStartupEvent ev)
@@ -208,7 +208,10 @@ namespace Robust.Client.Graphics.Clyde
             var data = _mapChunkData[gridId];
             foreach (var chunkDatum in data.Values)
             {
-                DeleteChunk(chunkDatum);
+                DeleteVertexArray(chunkDatum.VAO);
+                CheckGlError();
+                chunkDatum.VBO.Delete();
+                chunkDatum.EBO.Delete();
             }
 
             _mapChunkData.Remove(gridId);

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

@@ -350,7 +350,7 @@ namespace Robust.Client.Graphics.Clyde
                         _renderHandle.Viewport(Box2i.FromDimensions(-flippedPos, screenSize));
 
                         if (entry.Sprite.RaiseShaderEvent)
-                            _entityManager.EventBus.RaiseLocalEvent(entry.Uid,
+                            _entityManager.EventBus.RaiseLocalEvent(entry.Sprite.Owner,
                                 new BeforePostShaderRenderEvent(entry.Sprite, viewport), false);
                     }
                 }

Robust.Client/Graphics/Clyde/Clyde.Sprite.cs

@@ -1,3 +1,11 @@
+using Robust.Client.ComponentTrees;
+using Robust.Client.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Maths;
+using Robust.Shared.Physics;
+using Robust.Shared.Threading;
+using Robust.Shared.Utility;
 using System;
 using System.Buffers;
 using System.Collections.Generic;
@@ -6,15 +14,7 @@ using System.Runtime.CompilerServices;
 using System.Runtime.Intrinsics;
 using System.Runtime.Intrinsics.X86;
 using System.Threading.Tasks;
-using Robust.Client.ComponentTrees;
-using Robust.Client.GameObjects;
-using Robust.Shared.GameObjects;
 using Robust.Shared.Graphics;
-using Robust.Shared.Map;
-using Robust.Shared.Maths;
-using Robust.Shared.Physics;
-using Robust.Shared.Threading;
-using Robust.Shared.Utility;
 
 namespace Robust.Client.Graphics.Clyde;
 
@@ -260,7 +260,7 @@ internal partial class Clyde
             if (cmp != 0)
                 return cmp;
 
-            return a.Uid.CompareTo(b.Uid);
+            return a.Sprite.Owner.CompareTo(b.Sprite.Owner);
         }
     }
 }

Robust.Client/Graphics/Clyde/Clyde.cs

@@ -17,9 +17,11 @@ using Robust.Shared.IoC;
 using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
-using Robust.Shared.Maths;
 using Robust.Shared.Profiling;
 using Robust.Shared.Timing;
+using SixLabors.ImageSharp;
+using Color = Robust.Shared.Maths.Color;
+using DependencyAttribute = Robust.Shared.IoC.DependencyAttribute;
 using TextureWrapMode = Robust.Shared.Graphics.TextureWrapMode;
 
 namespace Robust.Client.Graphics.Clyde
@@ -173,6 +175,7 @@ namespace Robust.Client.Graphics.Clyde
             _entityManager.EventBus.SubscribeEvent<TileChangedEvent>(EventSource.Local, this, _updateTileMapOnUpdate);
             _entityManager.EventBus.SubscribeEvent<GridStartupEvent>(EventSource.Local, this, _updateOnGridCreated);
             _entityManager.EventBus.SubscribeEvent<GridRemovalEvent>(EventSource.Local, this, _updateOnGridRemoved);
+            _entityManager.EventBus.SubscribeEvent<GridModifiedEvent>(EventSource.Local, this, _updateOnGridModified);
         }
 
         public void ShutdownGridEcsEvents()
@@ -180,6 +183,7 @@ namespace Robust.Client.Graphics.Clyde
             _entityManager.EventBus.UnsubscribeEvent<TileChangedEvent>(EventSource.Local, this);
             _entityManager.EventBus.UnsubscribeEvent<GridStartupEvent>(EventSource.Local, this);
             _entityManager.EventBus.UnsubscribeEvent<GridRemovalEvent>(EventSource.Local, this);
+            _entityManager.EventBus.UnsubscribeEvent<GridModifiedEvent>(EventSource.Local, this);
         }
 
         private void GLInitBindings(bool gles)

Robust.Client/Map/TileEdgeOverlay.cs

@@ -1,13 +1,12 @@
 using System;
-using System.Collections.Generic;
 using System.Numerics;
 using Robust.Client.Graphics;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
-using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
+using Direction = Robust.Shared.Maths.Direction;
 
 namespace Robust.Client.Map;
 
@@ -23,8 +22,6 @@ public sealed class TileEdgeOverlay : Overlay
 
     public override OverlaySpace Space => OverlaySpace.WorldSpaceBelowEntities;
 
-    private List<Entity<MapGridComponent>> _grids = new();
-
     public TileEdgeOverlay(IEntityManager entManager, IMapManager mapManager, IResourceCache resource, ITileDefinitionManager tileDefManager)
     {
         _entManager = entManager;
@@ -39,18 +36,16 @@ public sealed class TileEdgeOverlay : Overlay
         if (args.MapId == MapId.Nullspace)
             return;
 
-        _grids.Clear();
-        _mapManager.FindGridsIntersecting(args.MapId, args.WorldBounds, ref _grids);
-
         var xformQuery = _entManager.GetEntityQuery<TransformComponent>();
-        foreach (var grid in _grids)
+
+        foreach (var grid in _mapManager.FindGridsIntersecting(args.MapId, args.WorldBounds))
         {
-            var tileSize = grid.Comp.TileSize;
+            var tileSize = grid.TileSize;
             var tileDimensions = new Vector2(tileSize, tileSize);
-            var xform = xformQuery.GetComponent(grid);
+            var xform = xformQuery.GetComponent(grid.Owner);
             args.WorldHandle.SetTransform(xform.WorldMatrix);
 
-            foreach (var tileRef in grid.Comp.GetTilesIntersecting(args.WorldBounds, false))
+            foreach (var tileRef in grid.GetTilesIntersecting(args.WorldBounds, false))
             {
                 var tileDef = _tileDefManager[tileRef.Tile.TypeId];
 
@@ -66,7 +61,7 @@ public sealed class TileEdgeOverlay : Overlay
                             continue;
 
                         var neighborIndices = new Vector2i(tileRef.GridIndices.X + x, tileRef.GridIndices.Y + y);
-                        var neighborTile = grid.Comp.GetTileRef(neighborIndices);
+                        var neighborTile = grid.GetTileRef(neighborIndices);
                         var neighborDef = _tileDefManager[neighborTile.Tile.TypeId];
 
                         // If it's the same tile then no edge to be drawn.

Robust.Client/Physics/PhysicsSystem.Predict.cs

@@ -1,6 +1,6 @@
 using System.Buffers;
 using System.Collections.Generic;
-using Robust.Client.Player;
+using Robust.Client.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Physics;
@@ -20,8 +20,8 @@ public sealed partial class PhysicsSystem
     public override void Initialize()
     {
         base.Initialize();
-        SubscribeLocalEvent<LocalPlayerAttachedEvent>(OnAttach);
-        SubscribeLocalEvent<LocalPlayerDetachedEvent>(OnDetach);
+        SubscribeLocalEvent<PlayerAttachedEvent>(OnAttach);
+        SubscribeLocalEvent<PlayerDetachedEvent>(OnDetach);
         SubscribeLocalEvent<PhysicsComponent, JointAddedEvent>(OnJointAdded);
         SubscribeLocalEvent<PhysicsComponent, JointRemovedEvent>(OnJointRemoved);
     }
@@ -63,12 +63,12 @@ public sealed partial class PhysicsSystem
         UpdateIsPredicted(args.Joint.BodyBUid);
     }
 
-    private void OnAttach(LocalPlayerAttachedEvent ev)
+    private void OnAttach(PlayerAttachedEvent ev)
     {
         UpdateIsPredicted(ev.Entity);
     }
 
-    private void OnDetach(LocalPlayerDetachedEvent ev)
+    private void OnDetach(PlayerDetachedEvent ev)
     {
         UpdateIsPredicted(ev.Entity);
     }

Robust.Client/Physics/PhysicsSystem.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using JetBrains.Annotations;
+using Robust.Client.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Physics;
@@ -25,7 +26,7 @@ namespace Robust.Client.Physics
 
         protected override void Cleanup(PhysicsMapComponent component, float frameTime)
         {
-            var toRemove = new List<Entity<PhysicsComponent>>();
+            var toRemove = new List<PhysicsComponent>();
 
             // Because we're not predicting 99% of bodies its sleep timer never gets incremented so we'll just do it ourselves.
             // (and serializing it over the network isn't necessary?)
@@ -37,13 +38,13 @@ namespace Robust.Client.Physics
                 body.SleepTime += frameTime;
                 if (body.SleepTime > TimeToSleep)
                 {
-                    toRemove.Add(new Entity<PhysicsComponent>(body.Owner, body));
+                    toRemove.Add(body);
                 }
             }
 
             foreach (var body in toRemove)
             {
-                SetAwake(body, false);
+                SetAwake(body.Owner, body, false);
             }
 
             base.Cleanup(component, frameTime);

Robust.Client/Placement/PlacementManager.cs

@@ -8,6 +8,7 @@ using Robust.Client.Player;
 using Robust.Client.ResourceManagement;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
+using Robust.Shared.Graphics;
 using Robust.Shared.Input;
 using Robust.Shared.Input.Binding;
 using Robust.Shared.IoC;
@@ -286,17 +287,23 @@ namespace Robust.Client.Placement
                     }, outsidePrediction: true))
                 .Register<PlacementManager>();
 
-            PlayerManager.LocalPlayerDetached += OnDetached;
+            var localPlayer = PlayerManager.LocalPlayer;
+            localPlayer!.EntityAttached += OnEntityAttached;
         }
 
         private void TearDownInput()
         {
             CommandBinds.Unregister<PlacementManager>();
-            PlayerManager.LocalPlayerDetached -= OnDetached;
+
+            if (PlayerManager.LocalPlayer != null)
+            {
+                PlayerManager.LocalPlayer.EntityAttached -= OnEntityAttached;
+            }
         }
 
-        private void OnDetached(EntityUid obj)
+        private void OnEntityAttached(EntityAttachedEventArgs eventArgs)
         {
+            // player attached to a new entity, basically disable the editor
             Clear();
         }
 

Robust.Client/Player/IPlayerManager.cs

@@ -1,71 +1,44 @@
 using System;
 using System.Collections.Generic;
-using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
+using Robust.Shared.ViewVariables;
 
-namespace Robust.Client.Player;
-
-public interface IPlayerManager : ISharedPlayerManager
+namespace Robust.Client.Player
 {
-    /// <summary>
-    /// Invoked when the list of sessions/players gets updated.
-    /// </summary>
-    event Action? PlayerListUpdated;
-
-    /// <summary>
-    /// Invoked when <see cref="ISharedPlayerManager.LocalSession"/> gets attached to a new entity. See also <see cref="LocalPlayerAttachedEvent"/>
-    /// </summary>
-    event Action<EntityUid>? LocalPlayerAttached;
-
-    /// <summary>
-    /// Invoked when <see cref="ISharedPlayerManager.LocalSession"/> gets detached from new entity. See also <see cref="LocalPlayerDetachedEvent"/>
-    /// </summary>
-    event Action<EntityUid>? LocalPlayerDetached;
-
-    void ApplyPlayerStates(IReadOnlyCollection<SessionState> list);
-
-    /// <summary>
-    /// Sets up a single player game. This creates a dummy <see cref="ISharedPlayerManager.LocalSession"/>  without an
-    /// <see cref="INetChannel"/>.
-    /// </summary>
-    void SetupSinglePlayer(string name);
-
-    /// <summary>
-    /// Sets up the manager for a multiplayer game. This creates a <see cref="ISharedPlayerManager.LocalSession"/>
-    /// using the given <see cref="INetChannel"/>.
-    /// </summary>
-    void SetupMultiplayer(INetChannel channel);
-
-    [Obsolete("Use LocalSession instead")]
-    LocalPlayer? LocalPlayer { get;}
-}
-
-/// <summary>
-/// ECS event that gets raised when the local player gets attached to a new entity. The event is both broadcast and
-/// raised directed at the new entity.
-/// </summary>
-public sealed class LocalPlayerAttachedEvent : EntityEventArgs
-{
-    public LocalPlayerAttachedEvent(EntityUid entity)
+    public interface IPlayerManager : ISharedPlayerManager
     {
-        Entity = entity;
+        new IEnumerable<ICommonSession> Sessions { get; }
+
+        [ViewVariables]
+        IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict { get; }
+
+        [ViewVariables]
+        LocalPlayer? LocalPlayer { get; }
+
+        /// <summary>
+        /// Invoked after LocalPlayer is changed
+        /// </summary>
+        event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
+
+        event EventHandler PlayerListUpdated;
+
+        void Initialize();
+        void Startup();
+        void Shutdown();
+
+        void ApplyPlayerStates(IReadOnlyCollection<PlayerState> list);
     }
 
-    public EntityUid Entity { get; }
-}
-
-/// <summary>
-/// ECS event that gets raised when the local player gets detached from an entity. The event is both broadcast and
-/// raised directed at the new entity.
-/// </summary>
-public sealed class LocalPlayerDetachedEvent : EntityEventArgs
-{
-    public LocalPlayerDetachedEvent(EntityUid entity)
+    public sealed class LocalPlayerChangedEventArgs : EventArgs
     {
-        Entity = entity;
+        public readonly LocalPlayer? OldPlayer;
+        public readonly LocalPlayer? NewPlayer;
+        public LocalPlayerChangedEventArgs(LocalPlayer? oldPlayer, LocalPlayer? newPlayer)
+        {
+            OldPlayer = oldPlayer;
+            NewPlayer = newPlayer;
+        }
     }
-
-    public EntityUid Entity { get; }
-}
+}

Robust.Client/Player/LocalPlayer.cs

@@ -1,6 +1,11 @@
+using System;
+using Robust.Client.GameObjects;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Player
@@ -10,30 +15,163 @@ namespace Robust.Client.Player
     /// </summary>
     public sealed class LocalPlayer
     {
-        public LocalPlayer(ICommonSession session)
-        {
-            Session = session;
-        }
+        /// <summary>
+        ///     An entity has been attached to the local player.
+        /// </summary>
+        public event Action<EntityAttachedEventArgs>? EntityAttached;
+
+        /// <summary>
+        ///     An entity has been detached from the local player.
+        /// </summary>
+        public event Action<EntityDetachedEventArgs>? EntityDetached;
 
         /// <summary>
         ///     Game entity that the local player is controlling. If this is default, the player is not attached to any
         ///     entity at all.
         /// </summary>
-        [ViewVariables]
-        public EntityUid? ControlledEntity => Session.AttachedEntity;
+        [ViewVariables] public EntityUid? ControlledEntity { get; private set; }
 
+        [ViewVariables] public NetUserId UserId { get; set; }
+
+        /// <summary>
+        ///     Session of the local client.
+        /// </summary>
         [ViewVariables]
-        public NetUserId UserId => Session.UserId;
+        public ICommonSession Session => InternalSession;
+
+        internal PlayerSession InternalSession { get; set; } = default!;
 
         /// <summary>
         ///     OOC name of the local player.
         /// </summary>
         [ViewVariables]
-        public string Name => Session.Name;
+        public string Name { get; set; } = default!;
 
         /// <summary>
-        ///     Session of the local client.
+        ///     The status of the client's session has changed.
         /// </summary>
-        public  ICommonSession Session;
+        public event EventHandler<StatusEventArgs>? StatusChanged;
+
+        /// <summary>
+        ///     Attaches a client to an entity.
+        /// </summary>
+        /// <param name="entity">Entity to attach the client to.</param>
+        public void AttachEntity(EntityUid entity, IEntityManager entMan, IBaseClient client)
+        {
+            if (ControlledEntity == entity)
+                return;
+
+            // Detach and cleanup first
+            DetachEntity();
+
+            if (!entMan.EntityExists(entity))
+            {
+                Logger.Error($"Attempting to attach player to non-existent entity {entity}!");
+                return;
+            }
+
+            ControlledEntity = entity;
+            InternalSession.AttachedEntity = entity;
+
+            if (!entMan.TryGetComponent<EyeComponent?>(entity, out var eye))
+            {
+                eye = entMan.AddComponent<EyeComponent>(entity);
+
+                if (client.RunLevel != ClientRunLevel.SinglePlayerGame)
+                {
+                    Logger.Warning($"Attaching local player to an entity {entMan.ToPrettyString(entity)} without an eye. This eye will not be netsynced and may cause issues.");
+                }
+                eye.NetSyncEnabled = false;
+            }
+
+            EntityAttached?.Invoke(new EntityAttachedEventArgs(entity));
+
+            // notify ECS Systems
+            var eventBus = entMan.EventBus;
+            eventBus.RaiseEvent(EventSource.Local, new PlayerAttachSysMessage(entity));
+            eventBus.RaiseLocalEvent(entity, new PlayerAttachedEvent(entity), true);
+        }
+
+        /// <summary>
+        ///     Detaches the client from an entity.
+        /// </summary>
+        public void DetachEntity()
+        {
+            var entMan = IoCManager.Resolve<IEntityManager>();
+            var previous = ControlledEntity;
+
+            ControlledEntity = null;
+            InternalSession.AttachedEntity = null;
+
+            if (previous != null)
+            {
+                entMan.EventBus.RaiseEvent(EventSource.Local, new PlayerAttachSysMessage(default));
+                entMan.EventBus.RaiseLocalEvent(previous.Value, new PlayerDetachedEvent(previous.Value), true);
+                EntityDetached?.Invoke(new EntityDetachedEventArgs(previous.Value));
+            }
+        }
+
+        /// <summary>
+        ///     Changes the state of the session.
+        /// </summary>
+        public void SwitchState(SessionStatus newStatus)
+        {
+            SwitchState(Session.Status, newStatus);
+        }
+
+        /// <summary>
+        ///     Changes the state of the session. This overload allows you to spoof the oldStatus, use with caution.
+        /// </summary>
+        public void SwitchState(SessionStatus oldStatus, SessionStatus newStatus)
+        {
+            var args = new StatusEventArgs(oldStatus, newStatus);
+            Session.Status = newStatus;
+            StatusChanged?.Invoke(this, args);
+        }
+    }
+
+    /// <summary>
+    ///     Event arguments for when the status of a session changes.
+    /// </summary>
+    public sealed class StatusEventArgs : EventArgs
+    {
+        /// <summary>
+        ///     Status that the session switched from.
+        /// </summary>
+        public SessionStatus OldStatus { get; }
+
+        /// <summary>
+        ///     Status that the session switched to.
+        /// </summary>
+        public SessionStatus NewStatus { get; }
+
+        /// <summary>
+        ///     Constructs a new instance of the class.
+        /// </summary>
+        public StatusEventArgs(SessionStatus oldStatus, SessionStatus newStatus)
+        {
+            OldStatus = oldStatus;
+            NewStatus = newStatus;
+        }
+    }
+
+    public sealed class EntityDetachedEventArgs : EventArgs
+    {
+        public EntityDetachedEventArgs(EntityUid oldEntity)
+        {
+            OldEntity = oldEntity;
+        }
+
+        public EntityUid OldEntity { get; }
+    }
+
+    public sealed class EntityAttachedEventArgs : EventArgs
+    {
+        public EntityAttachedEventArgs(EntityUid newEntity)
+        {
+            NewEntity = newEntity;
+        }
+
+        public EntityUid NewEntity { get; }
     }
 }

Robust.Client/Player/PlayerManager.cs

@@ -2,13 +2,16 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Player
 {
@@ -17,187 +20,154 @@ namespace Robust.Client.Player
     ///     Why not just attach the inputs directly? It's messy! This makes the whole thing nicely encapsulated.
     ///     This class also communicates with the server to let the server control what entity it is attached to.
     /// </summary>
-    internal sealed class PlayerManager : SharedPlayerManager, IPlayerManager
+    public sealed class PlayerManager : IPlayerManager
     {
         [Dependency] private readonly IClientNetManager _network = default!;
         [Dependency] private readonly IBaseClient _client = default!;
+        [Dependency] private readonly IEntityManager _entManager = default!;
+        [Dependency] private readonly ILogManager _logMan = default!;
 
         /// <summary>
-        /// Received player states that had an unknown <see cref="NetEntity"/>.
+        ///     Active sessions of connected clients to the server.
         /// </summary>
-        private Dictionary<NetUserId, SessionState> _pendingStates = new ();
-        private List<SessionState> _pending = new();
+        private readonly Dictionary<NetUserId, ICommonSession> _sessions = new();
 
         /// <inheritdoc />
-        public override ICommonSession[] NetworkedSessions
+        public IEnumerable<ICommonSession> NetworkedSessions
         {
             get
             {
-                return LocalSession != null
-                    ? new [] { LocalSession }
-                    : Array.Empty<ICommonSession>();
+                if (LocalPlayer is not null)
+                    return new[] {LocalPlayer.Session};
+
+                return Enumerable.Empty<ICommonSession>();
             }
         }
 
         /// <inheritdoc />
-        public override int MaxPlayers => _client.GameInfo?.ServerMaxPlayers ?? -1;
-
-        public LocalPlayer? LocalPlayer { get; set; }
-
-        public event Action<SessionStatusEventArgs>? LocalStatusChanged;
-        public event Action? PlayerListUpdated;
-        public event Action<EntityUid>? LocalPlayerDetached;
-        public event Action<EntityUid>? LocalPlayerAttached;
+        IEnumerable<ICommonSession> ISharedPlayerManager.Sessions => _sessions.Values;
 
         /// <inheritdoc />
-        public override void Initialize(int maxPlayers)
+        public int PlayerCount => _sessions.Values.Count;
+
+        /// <inheritdoc />
+        public int MaxPlayers => _client.GameInfo?.ServerMaxPlayers ?? 0;
+
+        public ICommonSession? LocalSession => LocalPlayer?.Session;
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public LocalPlayer? LocalPlayer
         {
-            base.Initialize(maxPlayers);
+            get => _localPlayer;
+            private set
+            {
+                if (_localPlayer == value) return;
+                var oldValue = _localPlayer;
+                _localPlayer = value;
+                LocalPlayerChanged?.Invoke(new LocalPlayerChangedEventArgs(oldValue, _localPlayer));
+            }
+        }
+        private LocalPlayer? _localPlayer;
+        private ISawmill _sawmill = default!;
+
+        public event Action<LocalPlayerChangedEventArgs>? LocalPlayerChanged;
+
+        /// <inheritdoc />
+        [ViewVariables]
+        IEnumerable<ICommonSession> IPlayerManager.Sessions => _sessions.Values;
+
+        /// <inheritdoc />
+        public IReadOnlyDictionary<NetUserId, ICommonSession> SessionsDict => _sessions;
+
+        /// <inheritdoc />
+        public event EventHandler? PlayerListUpdated;
+
+        /// <inheritdoc />
+        public void Initialize()
+        {
+            _client.RunLevelChanged += OnRunLevelChanged;
+
+            _sawmill = _logMan.GetSawmill("player");
             _network.RegisterNetMessage<MsgPlayerListReq>();
             _network.RegisterNetMessage<MsgPlayerList>(HandlePlayerList);
-            PlayerStatusChanged += StatusChanged;
-        }
-
-        private void StatusChanged(object? sender, SessionStatusEventArgs e)
-        {
-            if (e.Session == LocalPlayer?.Session)
-                LocalStatusChanged?.Invoke(e);
         }
 
         /// <inheritdoc />
-        public override void Startup()
+        public void Startup()
         {
-            if (LocalSession == null)
-                throw new InvalidOperationException("LocalSession cannot be null");
+            DebugTools.Assert(LocalPlayer == null);
+            LocalPlayer = new LocalPlayer();
 
-            LocalPlayer = new LocalPlayer(LocalSession);
-            base.Startup();
-        }
-
-        public void SetupSinglePlayer(string name)
-        {
-            if (LocalSession != null)
-                throw new InvalidOperationException($"Player manager already running?");
-
-            LocalSession = CreateAndAddSession(default, name);
-            Startup();
-            PlayerListUpdated?.Invoke();
-        }
-
-        public void SetupMultiplayer(INetChannel channel)
-        {
-            if (LocalSession != null)
-                throw new InvalidOperationException($"Player manager already running?");
-
-            var session = CreateAndAddSession(channel.UserId, channel.UserName);
-            session.Channel = channel;
-            LocalSession = session;
-            Startup();
-            _network.ClientSendMessage(new MsgPlayerListReq());
+            var msgList = new MsgPlayerListReq();
+            // message is empty
+            _network.ClientSendMessage(msgList);
         }
 
         /// <inheritdoc />
-        public override void Shutdown()
+        public void Shutdown()
         {
-            if (LocalSession != null)
-                SetAttachedEntity(LocalSession, null);
+            LocalPlayer?.DetachEntity();
             LocalPlayer = null;
-            LocalSession = null;
-            _pendingStates.Clear();
-            base.Shutdown();
-            PlayerListUpdated?.Invoke();
+            _sessions.Clear();
         }
 
-        public override void SetAttachedEntity(ICommonSession session, EntityUid? uid)
-        {
-            if (session.AttachedEntity == uid)
-                return;
-
-            var old = session.AttachedEntity;
-            base.SetAttachedEntity(session, uid);
-
-            if (session != LocalSession)
-                return;
-
-            if (old.HasValue)
-            {
-                Sawmill.Info($"Detaching local player from {EntManager.ToPrettyString(old)}.");
-                EntManager.EventBus.RaiseLocalEvent(old.Value, new LocalPlayerDetachedEvent(old.Value), true);
-                LocalPlayerDetached?.Invoke(old.Value);
-            }
-
-            if (uid == null)
-            {
-                Sawmill.Info($"Local player is no longer attached to any entity.");
-                return;
-            }
-
-            if (!EntManager.EntityExists(uid))
-            {
-                Sawmill.Error($"Attempted to attach player to non-existent entity {uid}!");
-                return;
-            }
-
-            if (!EntManager.EnsureComponent(uid.Value, out EyeComponent eye))
-            {
-                if (_client.RunLevel != ClientRunLevel.SinglePlayerGame)
-                    Sawmill.Warning($"Attaching local player to an entity {EntManager.ToPrettyString(uid)} without an eye. This eye will not be netsynced and may cause issues.");
-                eye.NetSyncEnabled = false;
-            }
-
-            Sawmill.Info($"Attaching local player to {EntManager.ToPrettyString(uid)}.");
-            EntManager.EventBus.RaiseLocalEvent(uid.Value, new LocalPlayerAttachedEvent(uid.Value), true);
-            LocalPlayerAttached?.Invoke(uid.Value);
-        }
-
-        public void ApplyPlayerStates(IReadOnlyCollection<SessionState> list)
-        {
-            var dirty = ApplyStates(list, true);
-
-            if (_pendingStates.Count == 0)
-            {
-                // This is somewhat inefficient as it might try to re-apply states that failed just a moment ago.
-                _pending.Clear();
-                _pending.AddRange(_pendingStates.Values);
-                _pendingStates.Clear();
-                dirty |= ApplyStates(_pending, false);
-            }
-
-            if (dirty)
-                PlayerListUpdated?.Invoke();
-        }
-
-        private bool ApplyStates(IReadOnlyCollection<SessionState> list, bool fullList)
+        /// <inheritdoc />
+        public void ApplyPlayerStates(IReadOnlyCollection<PlayerState> list)
         {
             if (list.Count == 0)
-                return false;
-
+            {
+                // This happens when the server says "nothing changed!"
+                return;
+            }
             DebugTools.Assert(_network.IsConnected ||  _client.RunLevel == ClientRunLevel.SinglePlayerGame // replays use state application.
                 , "Received player state without being connected?");
-            DebugTools.Assert(LocalSession != null, "Received player state before Session finished setup.");
+            DebugTools.Assert(LocalPlayer != null, "Call Startup()");
+            DebugTools.Assert(LocalPlayer!.Session != null, "Received player state before Session finished setup.");
 
-            var state = list.FirstOrDefault(s => s.UserId == LocalSession.UserId);
+            var myState = list.FirstOrDefault(s => s.UserId == LocalPlayer.UserId);
 
-            bool dirty = false;
-            if (state != null)
+            if (myState != null)
             {
-                dirty = true;
-                if (!EntManager.TryGetEntity(state.ControlledEntity, out var uid)
-                    && state.ControlledEntity is { Valid:true } )
+                var uid = _entManager.GetEntity(myState.ControlledEntity);
+                if (myState.ControlledEntity is {Valid: true} && !_entManager.EntityExists(uid))
                 {
-                    Sawmill.Error($"Received player state for local player with an unknown net entity!");
-                    _pendingStates[state.UserId] = state;
-                }
-                else
-                {
-                    _pendingStates.Remove(state.UserId);
+                    _sawmill.Error($"Received player state for local player with an unknown net entity!");
                 }
 
-                SetAttachedEntity(LocalSession, uid);
-                SetStatus(LocalSession, state.Status);
+                UpdateAttachedEntity(uid);
+                UpdateSessionStatus(myState.Status);
             }
 
-            return UpdatePlayerList(list, fullList) || dirty;
+            UpdatePlayerList(list);
+        }
+
+        /// <summary>
+        ///     Compares the server sessionStatus to the client one, and updates if needed.
+        /// </summary>
+        private void UpdateSessionStatus(SessionStatus myStateStatus)
+        {
+            if (LocalPlayer!.Session.Status != myStateStatus)
+                LocalPlayer.SwitchState(myStateStatus);
+        }
+
+        /// <summary>
+        ///     Compares the server attachedEntity to the client one, and updates if needed.
+        /// </summary>
+        /// <param name="entity">AttachedEntity in the server session.</param>
+        private void UpdateAttachedEntity(EntityUid? entity)
+        {
+            if (LocalPlayer!.ControlledEntity == entity)
+            {
+                return;
+            }
+            if (entity == null)
+            {
+                LocalPlayer.DetachEntity();
+                return;
+            }
+
+            LocalPlayer.AttachEntity(entity.Value, _entManager, _client);
         }
 
         /// <summary>
@@ -205,87 +175,117 @@ namespace Robust.Client.Player
         /// </summary>
         private void HandlePlayerList(MsgPlayerList msg)
         {
-            ApplyPlayerStates(msg.Plyrs);
+            UpdatePlayerList(msg.Plyrs);
         }
 
         /// <summary>
         ///     Compares the server player list to the client one, and updates if needed.
         /// </summary>
-        private bool UpdatePlayerList(IEnumerable<SessionState> remotePlayers, bool fullList)
+        private void UpdatePlayerList(IEnumerable<PlayerState> remotePlayers)
         {
             var dirty = false;
-            var users = new List<NetUserId>();
+
+            var hitSet = new List<NetUserId>();
+
             foreach (var state in remotePlayers)
             {
-                users.Add(state.UserId);
+                hitSet.Add(state.UserId);
 
-                if (!EntManager.TryGetEntity(state.ControlledEntity, out var controlled)
-                    && state.ControlledEntity is {Valid: true})
+                if (_sessions.TryGetValue(state.UserId, out var session))
                 {
-                    _pendingStates[state.UserId] = state;
+                    var local = (PlayerSession) session;
+                    var controlled = _entManager.GetEntity(state.ControlledEntity);
+
+                    // Exists, update data.
+                    if (local.Name == state.Name
+                        && local.Status == state.Status
+                        && local.Ping == state.Ping
+                        && local.AttachedEntity == controlled)
+                    {
+                        continue;
+                    }
+
+                    dirty = true;
+                    local.Name = state.Name;
+                    local.Status = state.Status;
+                    local.Ping = state.Ping;
+                    local.AttachedEntity = controlled;
                 }
                 else
                 {
-                    _pendingStates.Remove(state.UserId);
-                }
-
-                if (!InternalSessions.TryGetValue(state.UserId, out var session))
-                {
-                    // This is a new userid, so we create a new session.
-                    DebugTools.Assert(state.UserId != LocalPlayer?.UserId);
-                    var newSession = CreateAndAddSession(state.UserId, state.Name);
-                    newSession.Ping = state.Ping;
-                    newSession.Name = state.Name;
-                    SetStatus(newSession, state.Status);
-                    SetAttachedEntity(newSession, controlled);
+                    // New, give him a slot.
                     dirty = true;
-                    continue;
-                }
 
-                // Check if the data is actually different
-                if (session.Name == state.Name
-                    && session.Status == state.Status
-                    && session.Ping == state.Ping
-                    && session.AttachedEntity == controlled)
-                {
-                    continue;
+                    var newSession = new PlayerSession(state.UserId)
+                    {
+                        Name = state.Name,
+                        Status = state.Status,
+                        Ping = state.Ping,
+                        AttachedEntity = _entManager.GetEntity(state.ControlledEntity),
+                    };
+                    _sessions.Add(state.UserId, newSession);
+                    if (state.UserId == LocalPlayer!.UserId)
+                    {
+                        LocalPlayer.InternalSession = newSession;
+                        newSession.ConnectedClient = _network.ServerChannel!;
+                        // We just connected to the server, hurray!
+                        LocalPlayer.SwitchState(SessionStatus.Connecting, newSession.Status);
+                    }
                 }
-
-                dirty = true;
-                var local = (CommonSession) session;
-                local.Name = state.Name;
-                local.Ping = state.Ping;
-                SetStatus(local, state.Status);
-                SetAttachedEntity(local, controlled);
             }
 
-            // Remove old users. This only works if the provided state is a list of all players
-            if (fullList)
+            foreach (var existing in _sessions.Keys.ToArray())
             {
-                foreach (var oldUser in InternalSessions.Keys.ToArray())
+                // clear slot, player left
+                if (!hitSet.Contains(existing))
                 {
-                    // clear slot, player left
-                    if (users.Contains(oldUser))
-                        continue;
-
-                    DebugTools.Assert(oldUser != LocalUser
-                                      || LocalUser == null
-                                      || LocalUser == default(NetUserId),
-                        "Client is still connected to the server but not in the list of players?");
-                    RemoveSession(oldUser);
-                    _pendingStates.Remove(oldUser);
+                    DebugTools.Assert(LocalPlayer!.UserId != existing || _client.RunLevel == ClientRunLevel.SinglePlayerGame, // replays apply player states.
+                        "I'm still connected to the server, but i left?");
+                    _sessions.Remove(existing);
                     dirty = true;
                 }
             }
 
-            return dirty;
+            if (dirty)
+            {
+                PlayerListUpdated?.Invoke(this, EventArgs.Empty);
+            }
         }
 
-        public override bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
+        private void OnRunLevelChanged(object? sender, RunLevelChangedEventArgs e)
         {
-            if (LocalEntity == uid)
+            if (e.NewLevel != ClientRunLevel.SinglePlayerGame)
+                return;
+
+            DebugTools.AssertNotNull(LocalPlayer);
+
+            // We do some further setup steps for singleplayer here...
+
+            // The local player's GUID in singleplayer will always be the default.
+            var guid = default(NetUserId);
+
+            var session = new PlayerSession(guid)
             {
-                session = LocalSession!;
+                Name = LocalPlayer!.Name,
+                Ping = 0,
+            };
+
+            LocalPlayer.UserId = guid;
+            LocalPlayer.InternalSession = session;
+
+            // Add the local session to the list.
+            _sessions.Add(guid, session);
+
+            LocalPlayer.SwitchState(SessionStatus.InGame);
+
+            PlayerListUpdated?.Invoke(this, EventArgs.Empty);
+        }
+
+        public bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
+        {
+            if (LocalPlayer?.ControlledEntity == uid)
+            {
+                session = LocalPlayer.Session;
                 return true;
             }
 

Robust.Client/Player/PlayerSession.cs

@@ -0,0 +1,60 @@
+using Robust.Shared.Enums;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Network;
+using Robust.Shared.Players;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Client.Player
+{
+    internal sealed class PlayerSession : ICommonSession
+    {
+        internal SessionStatus Status { get; set; } = SessionStatus.Connecting;
+
+        /// <inheritdoc />
+        SessionStatus ICommonSession.Status
+        {
+            get => this.Status;
+            set => this.Status = value;
+        }
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public EntityUid? AttachedEntity { get; set; }
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public NetUserId UserId { get; }
+
+        [ViewVariables]
+        internal string Name { get; set; } = "<Unknown>";
+
+        /// <inheritdoc />
+        string ICommonSession.Name
+        {
+            get => this.Name;
+            set => this.Name = value;
+        }
+
+        [ViewVariables]
+        internal short Ping { get; set; }
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public INetChannel ConnectedClient { get; internal set; } = null!;
+
+        /// <inheritdoc />
+        short ICommonSession.Ping
+        {
+            get => this.Ping;
+            set => this.Ping = value;
+        }
+
+        /// <summary>
+        ///     Creates an instance of a PlayerSession.
+        /// </summary>
+        public PlayerSession(NetUserId user)
+        {
+            UserId = user;
+        }
+    }
+}

Robust.Client/Replays/Loading/ReplayLoadManager.Checkpoints.cs

@@ -7,6 +7,7 @@ using Robust.Shared.Network;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 using System.Threading.Tasks;
+using Robust.Client.Upload.Commands;
 using Robust.Shared;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Replays;
@@ -100,7 +101,7 @@ public sealed partial class ReplayLoadManager
 
         await callback(0, states.Count, LoadingState.ProcessingFiles, true);
         var playerSpan = state0.PlayerStates.Value;
-        Dictionary<NetUserId, SessionState> playerStates = new(playerSpan.Count);
+        Dictionary<NetUserId, PlayerState> playerStates = new(playerSpan.Count);
         foreach (var player in playerSpan)
         {
             playerStates.Add(player.UserId, player);
@@ -390,7 +391,7 @@ public sealed partial class ReplayLoadManager
         return new EntityState(newState.NetEntity, combined, newState.EntityLastModified, newState.NetComponents ?? oldNetComps);
     }
 
-    private void UpdatePlayerStates(ReadOnlySpan<SessionState> span, Dictionary<NetUserId, SessionState> playerStates)
+    private void UpdatePlayerStates(ReadOnlySpan<PlayerState> span, Dictionary<NetUserId, PlayerState> playerStates)
     {
         foreach (var player in span)
         {

Robust.Client/Replays/Playback/ReplayPlaybackManager.Time.cs

@@ -1,5 +1,4 @@
 using System;
-using Robust.Client.GameObjects;
 using Robust.Client.GameStates;
 using Robust.Shared.Utility;
 
@@ -59,10 +58,6 @@ internal sealed partial class ReplayPlaybackManager
 
             _timing.LastRealTick = _timing.LastProcessedTick = _timing.CurTick = Replay.CurTick;
             _gameState.UpdateFullRep(state, cloneDelta: true);
-
-            // Clear existing lerps
-            _entMan.EntitySysManager.GetEntitySystem<TransformSystem>().Reset();
-
             _gameState.ApplyGameState(state, Replay.NextState);
             ProcessMessages(Replay.CurMessages, skipEffectEvents);
 

Robust.Client/Replays/ReplayRecordingManager.cs

@@ -9,7 +9,7 @@ using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.IoC;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Replays;
 using Robust.Shared.Serialization.Markdown.Mapping;
 using Robust.Shared.Serialization.Markdown.Value;
@@ -138,9 +138,9 @@ internal sealed class ReplayRecordingManager : SharedReplayRecordingManager
         return (state, detachMsg);
     }
 
-    private SessionState GetPlayerState(ICommonSession session)
+    private PlayerState GetPlayerState(ICommonSession session)
     {
-        return new SessionState
+        return new PlayerState
         {
             UserId = session.UserId,
             Status = session.Status,

Robust.Client/Robust.Client.csproj

@@ -17,7 +17,7 @@
     <PackageReference Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.2" Condition="'$(UseSystemSqlite)' != 'True'" PrivateAssets="compile" />
     <PackageReference Include="SpaceWizards.NFluidsynth" Version="0.1.1" PrivateAssets="compile" />
     <PackageReference Include="NVorbis" Version="0.10.1" PrivateAssets="compile" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.7" />
     <PackageReference Include="OpenToolkit.Graphics" Version="4.0.0-pre9.1" PrivateAssets="compile" />
     <PackageReference Include="OpenTK.OpenAL" Version="4.7.5" PrivateAssets="compile" />
     <PackageReference Include="SpaceWizards.SharpFont" Version="1.0.1" PrivateAssets="compile" />

Robust.Client/UserInterface/Controls/SpriteView.cs

@@ -7,6 +7,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
+using Direction = Robust.Shared.Maths.Direction;
 
 namespace Robust.Client.UserInterface.Controls
 {
@@ -17,14 +18,18 @@ namespace Robust.Client.UserInterface.Controls
         IEntityManager _entMan;
 
         [ViewVariables]
-        public SpriteComponent? Sprite { get; private set; }
+        private SpriteComponent? _sprite;
+        public SpriteComponent? Sprite
+        {
+            get => _sprite;
+            [Obsolete("Use SetEntity()")]
+            set => SetEntity(value?.Owner);
+        }
 
 
         [ViewVariables]
         public EntityUid? Entity { get; private set; }
 
-        public Entity<SpriteComponent>? Ent => Entity == null || Sprite == null ? null : (Entity.Value, Sprite);
-
         /// <summary>
         /// This field configures automatic scaling of the sprite. This automatic scaling is done before
         /// applying the explicitly set scale <see cref="SpriteView.Scale"/>.
@@ -119,22 +124,14 @@ namespace Robust.Client.UserInterface.Controls
         public SpriteView()
         {
             _entMan = IoCManager.Resolve<IEntityManager>();
-            if (_entMan.TryGetComponent(Entity, out SpriteComponent? sprite))
-            {
-                Sprite = sprite;
-            }
-
+            _entMan.TryGetComponent(Entity, out _sprite);
             RectClipContent = true;
         }
 
         public void SetEntity(EntityUid? uid)
         {
             Entity = uid;
-
-            if (_entMan.TryGetComponent(Entity, out SpriteComponent? sprite))
-            {
-                Sprite = sprite;
-            }
+            _entMan.TryGetComponent(Entity, out _sprite);
         }
 
         protected override Vector2 MeasureOverride(Vector2 availableSize)
@@ -146,13 +143,13 @@ namespace Robust.Client.UserInterface.Controls
 
         private void UpdateSize()
         {
-            if (Entity == null || Sprite == null)
+            if (Entity == null || _sprite == null)
             {
                 _spriteSize = default;
                 return;
             }
 
-            var spriteBox = Sprite.CalculateRotatedBoundingBox(default,  _worldRotation ?? Angle.Zero, _eyeRotation)
+            var spriteBox = _sprite.CalculateRotatedBoundingBox(default,  _worldRotation ?? Angle.Zero, _eyeRotation)
                 .CalcBoundingBox();
 
             if (!SpriteOffset)
@@ -194,10 +191,10 @@ namespace Robust.Client.UserInterface.Controls
 
         internal override void DrawInternal(IRenderHandle renderHandle)
         {
-            if (Entity is not {} uid || Sprite == null)
+            if (Entity is not {} uid || _sprite == null)
                 return;
 
-            if (Sprite.Deleted)
+            if (_sprite.Deleted)
             {
                 SetEntity(null);
                 return;
@@ -217,11 +214,11 @@ namespace Robust.Client.UserInterface.Controls
 
             var offset = SpriteOffset
                 ? Vector2.Zero
-                : - (-_eyeRotation).RotateVec(Sprite.Offset) * new Vector2(1, -1) * EyeManager.PixelsPerMeter;
+                : - (-_eyeRotation).RotateVec(_sprite.Offset) * new Vector2(1, -1) * EyeManager.PixelsPerMeter;
 
             var position = PixelSize / 2 + offset * stretch * UIScale;
             var scale = Scale * UIScale * stretch;
-            renderHandle.DrawEntity(uid, position, scale, _worldRotation, _eyeRotation, OverrideDirection, Sprite);
+            renderHandle.DrawEntity(uid, position, scale, _worldRotation, _eyeRotation, OverrideDirection, _sprite);
         }
     }
 }

Robust.Client/UserInterface/CustomControls/DebugMonitorControls/DebugCoordsPanel.cs

@@ -117,7 +117,7 @@ Mouse Pos:
     {playerWorldOffset}
     {playerCoordinates}
     Rotation: {playerRotation.Degrees:F2}°
-    EntId: {controlledEntity}
+    EntId: {entityTransform.Owner}
     GridUid: {entityTransform.GridUid}
     Grid Rotation: {gridRotation.Degrees:F2}°");
             }

Robust.Client/ViewVariables/ClientViewVariablesManager.cs

@@ -15,7 +15,7 @@ using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;

Robust.Client/ViewVariables/Editors/VVPropEditorEntityCoordinates.cs

@@ -5,7 +5,7 @@ using Robust.Client.UserInterface.Controls;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
-using Robust.Shared.Map.Components;
+using Robust.Shared.Maths;
 using static Robust.Client.UserInterface.Controls.BoxContainer;
 
 namespace Robust.Client.ViewVariables.Editors
@@ -67,13 +67,13 @@ namespace Robust.Client.ViewVariables.Editors
                 var xVal = float.Parse(x.Text, CultureInfo.InvariantCulture);
                 var yVal = float.Parse(y.Text, CultureInfo.InvariantCulture);
 
-                if (!entityManager.HasComponent<MapGridComponent>(gridVal))
+                if (!mapManager.TryGetGrid(gridVal, out var grid))
                 {
                     ValueChanged(new EntityCoordinates(EntityUid.Invalid, new(xVal, yVal)));
                     return;
                 }
 
-                ValueChanged(new EntityCoordinates(gridVal, new(xVal, yVal)));
+                ValueChanged(new EntityCoordinates(grid.Owner, new(xVal, yVal)));
             }
 
             if (!ReadOnly)

Robust.Client/ViewVariables/Instances/ViewVariablesInstanceEntity.cs

@@ -120,11 +120,7 @@ namespace Robust.Client.ViewVariables.Instances
                     };
                     top.HorizontalExpand = true;
                     hBox.AddChild(top);
-
-                    var view = new SpriteView { OverrideDirection = Direction.South };
-                    view.SetEntity(_entity);
-                    hBox.AddChild(view);
-
+                    hBox.AddChild(new SpriteView {Sprite = sprite, OverrideDirection = Direction.South});
                     vBoxContainer.AddChild(hBox);
                 }
                 else
@@ -435,7 +431,8 @@ namespace Robust.Client.ViewVariables.Instances
 
             try
             {
-                var comp = componentFactory.GetComponent(registration.Type);
+                var comp = (Component) componentFactory.GetComponent(registration.Type);
+                comp.Owner = _entity;
                 _entityManager.AddComponent(_entity, comp);
             }
             catch (Exception e)

Robust.Packaging/AssetProcessing/Passes/AssetPassPackRsis.cs

@@ -61,7 +61,7 @@ internal sealed class AssetPassPackRsis : AssetPass
         foreach (var (key, dat) in _foundRsis)
         {
             if (dat.MetaJson == null)
-                continue;
+                return;
 
             RunJob(() =>
             {

Robust.Packaging/RobustClientAssetGraph.cs

@@ -21,11 +21,11 @@ public sealed class RobustClientAssetGraph
     /// </summary>
     public IReadOnlyCollection<AssetPass> AllPasses { get; }
 
-    public RobustClientAssetGraph(bool parallel = true)
+    public RobustClientAssetGraph()
     {
         // The code injecting the list of source files is assumed to be pretty single-threaded.
         // We use a parallelizing input to break out all the work on files coming in onto multiple threads.
-        Input = new AssetPassPipe { Name = "RobustClientAssetGraphInput", Parallelize = parallel };
+        Input = new AssetPassPipe { Name = "RobustClientAssetGraphInput", Parallelize = true };
         PresetPasses = new AssetPassPipe { Name = "RobustClientAssetGraphPresetPasses" };
         Output = new AssetPassPipe { Name = "RobustClientAssetGraphOutput", CheckDuplicates = true };
         NormalizeText = new AssetPassNormalizeText { Name = "RobustClientAssetGraphNormalizeText" };

Robust.Packaging/RobustClientPackaging.cs

@@ -4,10 +4,9 @@ namespace Robust.Packaging;
 
 public sealed class RobustClientPackaging
 {
-    public static IReadOnlySet<string> ClientIgnoredResources { get; } = new HashSet<string>
+    public static IReadOnlySet<string> ClientIgnoresResources { get; } = new HashSet<string>
     {
         "Maps",
-        "ConfigPresets",
         // Leaving this here for future archaeologists to ponder at.
         "emotes.xml",
         "Groups",
@@ -19,8 +18,48 @@ public sealed class RobustClientPackaging
         AssetPass pass,
         CancellationToken cancel = default)
     {
-        var ignoreSet = ClientIgnoredResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
+        var ignoreSet = ClientIgnoresResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
 
-        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"), pass, ignoreSet, cancel: cancel);
+        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"), pass, ignoreSet, cancel);
+    }
+
+    public static async Task WriteContentAssemblies(
+        AssetPass pass,
+        string contentDir,
+        string binDir,
+        IEnumerable<string> contentAssemblies,
+        CancellationToken cancel = default)
+    {
+        await WriteContentAssemblies("Assemblies", pass, contentDir, binDir, contentAssemblies, cancel);
+    }
+
+    public static Task WriteContentAssemblies(
+        string target,
+        AssetPass pass,
+        string contentDir,
+        string binDir,
+        IEnumerable<string> contentAssemblies,
+        CancellationToken cancel = default)
+    {
+        var files = new List<string>();
+
+        var sourceDir = Path.Combine(contentDir, "bin", binDir);
+
+        foreach (var asm in contentAssemblies)
+        {
+            files.Add($"{asm}.dll");
+
+            var pdbPath = $"{asm}.pdb";
+            if (File.Exists(Path.Combine(sourceDir, pdbPath)))
+                files.Add(pdbPath);
+        }
+
+        foreach (var f in files)
+        {
+            cancel.ThrowIfCancellationRequested();
+            pass.InjectFileFromDisk($"{target}/{f}", Path.Combine(sourceDir, f));
+        }
+
+        return Task.CompletedTask;
     }
 }

Robust.Packaging/RobustServerPackaging.cs

@@ -1,33 +0,0 @@
-using Robust.Packaging.AssetProcessing;
-
-namespace Robust.Packaging;
-
-public sealed class RobustServerPackaging
-{
-    public static IReadOnlySet<string> ServerIgnoresResources { get; } = new HashSet<string>
-    {
-        "Audio",
-        "Textures",
-        "Fonts",
-        "Shaders",
-    };
-
-    public static async Task WriteServerResources(
-        string contentDir,
-        AssetPass pass,
-        CancellationToken cancel = default)
-    {
-        var ignoreSet = ServerIgnoresResources.Union(RobustSharedPackaging.SharedIgnoredResources).ToHashSet();
-
-        await RobustSharedPackaging.DoResourceCopy(Path.Combine(contentDir, "Resources"),
-            pass,
-            ignoreSet,
-            "Resources",
-            cancel);
-        await RobustSharedPackaging.DoResourceCopy(Path.Combine("RobustToolbox", "Resources"),
-            pass,
-            ignoreSet,
-            "Resources",
-            cancel);
-    }
-}

Robust.Packaging/RobustSharedPackaging.cs

@@ -15,53 +15,10 @@ public sealed class RobustSharedPackaging
         ".DS_Store"
     };
 
-    // IDK what these are supposed to correspond to but targetDir is the target directory.
-    public static async Task WriteContentAssemblies(
-        AssetPass pass,
-        string contentDir,
-        string binDir,
-        IEnumerable<string> contentAssemblies,
-        string targetDir = "Assemblies",
-        CancellationToken cancel = default)
-    {
-        await WriteContentAssemblies(targetDir, pass, contentDir, binDir, contentAssemblies, cancel);
-    }
-
-    public static Task WriteContentAssemblies(
-        string target,
-        AssetPass pass,
-        string contentDir,
-        string binDir,
-        IEnumerable<string> contentAssemblies,
-        CancellationToken cancel = default)
-    {
-        var files = new List<string>();
-
-        var sourceDir = Path.Combine(contentDir, "bin", binDir);
-
-        foreach (var asm in contentAssemblies)
-        {
-            files.Add($"{asm}.dll");
-
-            var pdbPath = $"{asm}.pdb";
-            if (File.Exists(Path.Combine(sourceDir, pdbPath)))
-                files.Add(pdbPath);
-        }
-
-        foreach (var f in files)
-        {
-            cancel.ThrowIfCancellationRequested();
-            pass.InjectFileFromDisk($"{target}/{f}", Path.Combine(sourceDir, f));
-        }
-
-        return Task.CompletedTask;
-    }
-
     public static Task DoResourceCopy(
         string diskSource,
         AssetPass pass,
         IReadOnlySet<string> ignoreSet,
-        string targetDir = "",
         CancellationToken cancel = default)
     {
         foreach (var path in Directory.EnumerateFileSystemEntries(diskSource))
@@ -72,7 +29,7 @@ public sealed class RobustSharedPackaging
             if (ignoreSet.Contains(filename))
                 continue;
 
-            var targetPath = Path.Combine(targetDir, filename);
+            var targetPath = filename;
             if (Directory.Exists(path))
                 CopyDirIntoZip(path, targetPath, pass);
             else
@@ -87,10 +44,10 @@ public sealed class RobustSharedPackaging
         foreach (var file in Directory.EnumerateFiles(directory, "*.*", SearchOption.AllDirectories))
         {
             var relPath = Path.GetRelativePath(directory, file);
-            var zipPath = $"{basePath}/{relPath}";
-
             if (Path.DirectorySeparatorChar != '/')
-                zipPath = zipPath.Replace(Path.DirectorySeparatorChar, '/');
+                relPath = relPath.Replace(Path.DirectorySeparatorChar, '/');
+
+            var zipPath = $"{basePath}/{relPath}";
 
             // Console.WriteLine($"{directory}/{zipPath} -> /{zipPath}");
             pass.InjectFileFromDisk(zipPath, file);

Robust.Server/BaseServer.cs

@@ -28,7 +28,6 @@ using Robust.Shared.Localization;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
 using Robust.Shared.Profiling;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
@@ -307,9 +306,7 @@ namespace Robust.Server
             _modLoader.SetUseLoadContext(!ContentStart);
             _modLoader.SetEnableSandboxing(Options.Sandboxing);
 
-            var resourceManifest = ResourceManifestData.LoadResourceManifest(_resources);
-
-            if (!_modLoader.TryLoadModulesFrom(Options.AssemblyDirectory, resourceManifest.AssemblyPrefix ?? Options.ContentModulePrefix))
+            if (!_modLoader.TryLoadModulesFrom(Options.AssemblyDirectory, Options.ContentModulePrefix))
             {
                 _logger.Fatal("Errors while loading content assemblies.");
                 return true;

Robust.Server/Console/Commands/AddComponentCommand.cs

@@ -1,4 +1,5 @@
-using JetBrains.Annotations;
+using System;
+using JetBrains.Annotations;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -46,7 +47,11 @@ namespace Robust.Server.Console.Commands
                 shell.WriteLine($"Entity {_entityManager.GetComponent<MetaDataComponent>(uid.Value).EntityName} already has a {componentName} component.");
             }
 
-            var component = _componentFactory.GetComponent(registration.Type);
+            var component = (Component) _componentFactory.GetComponent(registration.Type);
+
+#pragma warning disable CS0618
+            component.Owner = uid.Value;
+#pragma warning restore CS0618
             _entityManager.AddComponent(uid.Value, component);
 
             shell.WriteLine($"Added {componentName} component to entity {_entityManager.GetComponent<MetaDataComponent>(uid.Value).EntityName}.");

Robust.Server/Console/Commands/DeleteCommand.cs

@@ -0,0 +1,37 @@
+using Robust.Server.GameObjects;
+using Robust.Shared.Console;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+
+namespace Robust.Server.Console.Commands
+{
+    public sealed class DeleteCommand : LocalizedCommands
+    {
+        [Dependency] private readonly IEntityManager _entityManager = default!;
+
+        public override string Command => "delete";
+
+        public override void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if (args.Length != 1)
+            {
+                shell.WriteLine("You should provide exactly one argument.");
+                return;
+            }
+
+            if (!NetEntity.TryParse(args[0], out var entityNet))
+            {
+                shell.WriteLine("Invalid entity UID.");
+                return;
+            }
+
+            if (!_entityManager.TryGetEntity(entityNet, out var entity) || !_entityManager.EntityExists(entity))
+            {
+                shell.WriteLine("That entity does not exist.");
+                return;
+            }
+
+            _entityManager.DeleteEntity(entity.Value);
+        }
+    }
+}

Robust.Server/Console/Commands/PlayerCommands.cs

@@ -21,7 +21,7 @@ namespace Robust.Server.Console.Commands
 
             var sb = new StringBuilder();
 
-            var players = _players.Sessions;
+            var players = _players.ServerSessions;
             sb.AppendLine($"{"Player Name",20} {"Status",12} {"Playing Time",14} {"Ping",9} {"IP EndPoint",20}");
             sb.AppendLine("-------------------------------------------------------------------------------");
 
@@ -50,8 +50,8 @@ namespace Robust.Server.Console.Commands
         {
             if (args.Length < 1)
             {
-                var player = shell.Player;
-                var toKickPlayer = player ?? _players.Sessions.FirstOrDefault();
+                var player = shell.Player as IPlayerSession;
+                var toKickPlayer = player ?? _players.ServerSessions.FirstOrDefault();
                 if (toKickPlayer == null)
                 {
                     shell.WriteLine("You need to provide a player to kick.");
@@ -79,7 +79,7 @@ namespace Robust.Server.Console.Commands
         {
             if (args.Length == 1)
             {
-                var options = _players.Sessions.OrderBy(c => c.Name).Select(c => c.Name).ToArray();
+                var options = _players.ServerSessions.OrderBy(c => c.Name).Select(c => c.Name).ToArray();
 
                 return CompletionResult.FromHintOptions(options, "<PlayerIndex>");
             }

Robust.Server/Console/Commands/ViewSubscriberCommand.cs

@@ -1,8 +1,9 @@
 using Robust.Server.GameObjects;
+using Robust.Server.Player;
 using Robust.Shared.Console;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 
 namespace Robust.Server.Console.Commands
 {
@@ -16,7 +17,7 @@ namespace Robust.Server.Console.Commands
         {
             var session = shell.Player;
 
-            if (session is not { } playerSession)
+            if (session is not IPlayerSession playerSession)
             {
                 shell.WriteError($"Unable to find {nameof(ICommonSession)} for shell");
                 return;
@@ -53,7 +54,7 @@ namespace Robust.Server.Console.Commands
             {
                 var session = shell.Player;
 
-                if (session is not { } playerSession)
+                if (session is not IPlayerSession playerSession)
                 {
                     shell.WriteError($"Unable to find {nameof(ICommonSession)} for shell");
                     return;

Robust.Server/Console/ConGroupController.cs

@@ -1,4 +1,6 @@
-using Robust.Shared.Player;
+using Robust.Server.Player;
+using Robust.Shared.Map;
+using Robust.Shared.Players;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Errors;
 
@@ -8,27 +10,27 @@ namespace Robust.Server.Console
     {
         public IConGroupControllerImplementation? Implementation { get; set; }
 
-        public bool CanCommand(ICommonSession session, string cmdName)
+        public bool CanCommand(IPlayerSession session, string cmdName)
         {
             return Implementation?.CanCommand(session, cmdName) ?? false;
         }
 
-        public bool CanAdminPlace(ICommonSession session)
+        public bool CanAdminPlace(IPlayerSession session)
         {
             return Implementation?.CanAdminPlace(session) ?? false;
         }
 
-        public bool CanScript(ICommonSession session)
+        public bool CanScript(IPlayerSession session)
         {
             return Implementation?.CanScript(session) ?? false;
         }
 
-        public bool CanAdminMenu(ICommonSession session)
+        public bool CanAdminMenu(IPlayerSession session)
         {
             return Implementation?.CanAdminMenu(session) ?? false;
         }
 
-        public bool CanAdminReloadPrototypes(ICommonSession session)
+        public bool CanAdminReloadPrototypes(IPlayerSession session)
         {
             return Implementation?.CanAdminReloadPrototypes(session) ?? false;
         }

Robust.Server/Console/IConGroupControllerImplementation.cs

@@ -1,14 +1,14 @@
-using Robust.Shared.Player;
+using Robust.Server.Player;
 using Robust.Shared.Toolshed;
 
 namespace Robust.Server.Console
 {
     public interface IConGroupControllerImplementation : IPermissionController
     {
-        bool CanCommand(ICommonSession session, string cmdName);
-        bool CanAdminPlace(ICommonSession session);
-        bool CanScript(ICommonSession session);
-        bool CanAdminMenu(ICommonSession session);
-        bool CanAdminReloadPrototypes(ICommonSession session);
+        bool CanCommand(IPlayerSession session, string cmdName);
+        bool CanAdminPlace(IPlayerSession session);
+        bool CanScript(IPlayerSession session);
+        bool CanAdminMenu(IPlayerSession session);
+        bool CanAdminReloadPrototypes(IPlayerSession session);
     }
 }

Robust.Server/Console/ServerConsoleHost.cs

@@ -5,9 +5,10 @@ using System.Threading.Tasks;
 using Robust.Server.Player;
 using Robust.Shared.Console;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Syntax;
 using Robust.Shared.Utility;
@@ -41,7 +42,7 @@ namespace Robust.Server.Console
 
             var msg = new MsgConCmd();
             msg.Text = command;
-            NetManager.ServerSendMessage(msg, session.Channel);
+            NetManager.ServerSendMessage(msg, ((IPlayerSession)session).ConnectedClient);
         }
 
         /// <inheritdoc />
@@ -49,12 +50,18 @@ namespace Robust.Server.Console
         {
             var msg = new FormattedMessage();
             msg.AddText(text);
-            OutputText(session, msg, false);
+            if (session is IPlayerSession playerSession)
+                OutputText(playerSession, msg, false);
+            else
+                OutputText(null, msg, false);
         }
 
         public override void WriteLine(ICommonSession? session, FormattedMessage msg)
         {
-            OutputText(session, msg, false);
+            if (session is IPlayerSession playerSession)
+                OutputText(playerSession, msg, false);
+            else
+                OutputText(null, msg, false);
         }
 
         /// <inheritdoc />
@@ -62,7 +69,10 @@ namespace Robust.Server.Console
         {
             var msg = new FormattedMessage();
             msg.AddText(text);
-            OutputText(session, msg, true);
+            if (session is IPlayerSession playerSession)
+                OutputText(playerSession, msg, true);
+            else
+                OutputText(null, msg, true);
         }
 
         public bool IsCmdServer(IConsoleCommand cmd) => true;
@@ -146,7 +156,7 @@ namespace Robust.Server.Console
 
         private bool ShellCanExecute(IConsoleShell shell, string cmdName)
         {
-            return shell.Player == null || _groupController.CanCommand(shell.Player, cmdName);
+            return shell.Player == null || _groupController.CanCommand((IPlayerSession)shell.Player, cmdName);
         }
 
         private void HandleRegistrationRequest(INetChannel senderConnection)
@@ -154,40 +164,16 @@ namespace Robust.Server.Console
             var message = new MsgConCmdReg();
 
             var counter = 0;
-            var toolshedCommands = _toolshed.DefaultEnvironment.AllCommands().ToArray();
-            message.Commands = new List<MsgConCmdReg.Command>(AvailableCommands.Count + toolshedCommands.Length);
-            var commands = new HashSet<string>();
+            message.Commands = new MsgConCmdReg.Command[AvailableCommands.Count];
 
             foreach (var command in AvailableCommands.Values)
             {
-                if (!commands.Add(command.Command))
-                {
-                    Sawmill.Error($"Duplicate command: {command.Command}");
-                    continue;
-                }
-                message.Commands.Add(new MsgConCmdReg.Command
+                message.Commands[counter++] = new MsgConCmdReg.Command
                 {
                     Name = command.Command,
                     Description = command.Description,
                     Help = command.Help
-                });
-            }
-
-            foreach (var spec in toolshedCommands)
-            {
-                var name = spec.FullName();
-                if (!commands.Add(name))
-                {
-                    Sawmill.Warning($"Duplicate toolshed command: {name}");
-                    continue;
-                }
-
-                message.Commands.Add(new MsgConCmdReg.Command
-                {
-                    Name = name,
-                    Description = spec.Cmd.Description(spec.SubCommand),
-                    Help = spec.Cmd.GetHelp(spec.SubCommand)
-                });
+                };
             }
 
             NetManager.ServerSendMessage(message, senderConnection);
@@ -204,7 +190,7 @@ namespace Robust.Server.Console
             ExecuteCommand(session, text);
         }
 
-        private void OutputText(ICommonSession? session, FormattedMessage text, bool error)
+        private void OutputText(IPlayerSession? session, FormattedMessage text, bool error)
         {
             if (session != null)
             {

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

@@ -0,0 +1,13 @@
+using Robust.Server.Player;
+using Robust.Shared.GameObjects;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Server.GameObjects
+{
+    [RegisterComponent]
+    public sealed partial class ActorComponent : Component
+    {
+        [ViewVariables]
+        public IPlayerSession PlayerSession { get; internal set; } = default!;
+    }
+}

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

@@ -1,12 +1,12 @@
 using System.Collections.Generic;
+using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
     [RegisterComponent]
     internal sealed partial class ViewSubscriberComponent : Component
     {
-        internal readonly HashSet<ICommonSession> SubscribedSessions = new();
+        internal readonly HashSet<IPlayerSession> SubscribedSessions = new();
     }
 }

Robust.Server/GameObjects/Components/VisibilityComponent.cs

@@ -1,5 +1,8 @@
+using System;
+using Robust.Shared.Analyzers;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.GameObjects
 {
@@ -13,5 +16,13 @@ namespace Robust.Server.GameObjects
         /// </summary>
         [DataField("layer")]
         public int Layer = 1;
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        [Obsolete("Do not access directly, only exists for VV")]
+        public int LayerVV
+        {
+            get => Layer;
+            set => EntitySystem.Get<VisibilitySystem>().SetLayer(this, value);
+        }
     }
 }

Robust.Server/GameObjects/EntitySystems/ActorSystem.cs

@@ -4,7 +4,6 @@ using Robust.Server.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
 using Robust.Shared.Utility;
 
 namespace Robust.Server.GameObjects
@@ -31,7 +30,7 @@ namespace Robust.Server.GameObjects
         /// <param name="player">The player to attach to the entity</param>
         /// <param name="force">Whether to kick any existing players from the entity</param>
         /// <returns>Whether the attach succeeded, or not.</returns>
-        public bool Attach(EntityUid? uid, ICommonSession player, bool force = false)
+        public bool Attach(EntityUid? uid, IPlayerSession player, bool force = false)
         {
             return Attach(uid, player, false, out _);
         }
@@ -44,26 +43,25 @@ namespace Robust.Server.GameObjects
         /// <param name="force">Whether to kick any existing players from the entity</param>
         /// <param name="forceKicked">The player that was forcefully kicked, or null.</param>
         /// <returns>Whether the attach succeeded, or not.</returns>
-        public bool Attach(EntityUid? entity, ICommonSession player, bool force, out ICommonSession? forceKicked)
+        public bool Attach(EntityUid? entity, IPlayerSession player, bool force, out IPlayerSession? forceKicked)
         {
             // Null by default.
             forceKicked = null;
 
             if (player.AttachedEntity == entity)
-            {
-                DebugTools.Assert(entity == null || HasComp<ActorComponent>(entity));
                 return true;
-            }
 
             if (entity is not { } uid)
                 return Detach(player);
 
             // Cannot attach to a deleted, nonexisting or terminating entity.
-            if (TerminatingOrDeleted(uid))
+            if (!TryComp(uid, out MetaDataComponent? meta) || meta.EntityLifeStage > EntityLifeStage.MapInitialized)
+            {
                 return false;
+            }
 
             // Check if there was a player attached to the entity already...
-            if (TryComp(uid, out ActorComponent? actor))
+            if (EntityManager.TryGetComponent(uid, out ActorComponent? actor))
             {
                 // If we're not forcing the attach, this fails.
                 if (!force)
@@ -71,22 +69,22 @@ namespace Robust.Server.GameObjects
 
                 // Set the event's force-kicked session before detaching it.
                 forceKicked = actor.PlayerSession;
-                RemComp(uid, actor);
-                DebugTools.AssertNull(forceKicked.AttachedEntity);
+                Detach(uid, actor);
             }
 
             // Detach from the currently attached entity.
-            Detach(player);
+            if (!Detach(player))
+                return false;
 
             // We add the actor component.
             actor = EntityManager.AddComponent<ActorComponent>(uid);
             EntityManager.EnsureComponent<EyeComponent>(uid);
             actor.PlayerSession = player;
-            _playerManager.SetAttachedEntity(player, uid);
-            DebugTools.Assert(player.AttachedEntity == entity);
+            player.SetAttachedEntity(uid);
 
             // The player is fully attached now, raise an event!
             RaiseLocalEvent(uid, new PlayerAttachedEvent(uid, player, forceKicked), true);
+            DebugTools.Assert(player.AttachedEntity == entity);
             return true;
         }
 
@@ -110,33 +108,21 @@ namespace Robust.Server.GameObjects
         /// <param name="player">The player session that will be detached from any attached entities.</param>
         /// <returns>Whether the player is now detached from any entities.
         /// This returns true if the player wasn't attached to any entity.</returns>
-        public bool Detach(ICommonSession player, ActorComponent? actor = null)
+        public bool Detach(IPlayerSession player)
         {
             var uid = player.AttachedEntity;
-            if (uid == null)
-                return true;
-
-            if (!Resolve(uid.Value, ref actor, false))
-            {
-                Log.Error($"Player {player} was attached to a deleted entity?");
-                ((CommonSession) player).AttachedEntity = null;
-                return true;
-            }
-
-            RemComp(uid.Value, actor);
-            DebugTools.AssertNull(player.AttachedEntity);
-            return false;
+            return uid == null || Detach(uid.Value);
         }
 
         private void OnActorShutdown(EntityUid entity, ActorComponent component, ComponentShutdown args)
         {
-            _playerManager.SetAttachedEntity(component.PlayerSession, null);
+            component.PlayerSession.SetAttachedEntity(null);
 
             // The player is fully detached now that the component has shut down.
             RaiseLocalEvent(entity, new PlayerDetachedEvent(entity, component.PlayerSession), true);
         }
 
-        public bool TryGetActorFromUserId(NetUserId? userId, [NotNullWhen(true)] out ICommonSession? actor, out EntityUid? actorEntity)
+        public bool TryGetActorFromUserId(NetUserId? userId, [NotNullWhen(true)] out IPlayerSession? actor, [MaybeNullWhen(true)] out EntityUid? actorEntity)
         {
             actor = null;
             actorEntity = null;
@@ -157,14 +143,14 @@ namespace Robust.Server.GameObjects
     public sealed class PlayerAttachedEvent : EntityEventArgs
     {
         public EntityUid Entity { get; }
-        public ICommonSession Player { get; }
+        public IPlayerSession Player { get; }
 
         /// <summary>
         ///     The player session that was forcefully kicked from the entity, if any.
         /// </summary>
-        public ICommonSession? Kicked { get; }
+        public IPlayerSession? Kicked { get; }
 
-        public PlayerAttachedEvent(EntityUid entity, ICommonSession player, ICommonSession? kicked = null)
+        public PlayerAttachedEvent(EntityUid entity, IPlayerSession player, IPlayerSession? kicked = null)
         {
             Entity = entity;
             Player = player;
@@ -178,9 +164,9 @@ namespace Robust.Server.GameObjects
     public sealed class PlayerDetachedEvent : EntityEventArgs
     {
         public EntityUid Entity { get; }
-        public ICommonSession Player { get; }
+        public IPlayerSession Player { get; }
 
-        public PlayerDetachedEvent(EntityUid entity, ICommonSession player)
+        public PlayerDetachedEvent(EntityUid entity, IPlayerSession player)
         {
             Entity = entity;
             Player = player;

Robust.Server/GameObjects/EntitySystems/AudioSystem.cs

@@ -6,6 +6,7 @@ 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]

Robust.Server/GameObjects/EntitySystems/InputSystem.cs

@@ -5,7 +5,6 @@ using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
-using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
@@ -16,10 +15,10 @@ namespace Robust.Server.GameObjects
     {
         [Dependency] private readonly IPlayerManager _playerManager = default!;
 
-        private readonly Dictionary<ICommonSession, IPlayerCommandStates> _playerInputs = new();
+        private readonly Dictionary<IPlayerSession, IPlayerCommandStates> _playerInputs = new();
 
 
-        private readonly Dictionary<ICommonSession, uint> _lastProcessedInputCmd = new();
+        private readonly Dictionary<IPlayerSession, uint> _lastProcessedInputCmd = new();
 
         /// <inheritdoc />
         public override void Initialize()
@@ -49,7 +48,7 @@ namespace Robust.Server.GameObjects
             if (!Enum.IsDefined(typeof(BoundKeyState), msg.State))
                 return;
 
-            var session = eventArgs.SenderSession;
+            var session = (IPlayerSession) eventArgs.SenderSession;
 
             if (_lastProcessedInputCmd[session] < msg.InputSequence)
                 _lastProcessedInputCmd[session] = msg.InputSequence;
@@ -66,12 +65,12 @@ namespace Robust.Server.GameObjects
             }
         }
 
-        public IPlayerCommandStates GetInputStates(ICommonSession session)
+        public IPlayerCommandStates GetInputStates(IPlayerSession session)
         {
             return _playerInputs[session];
         }
 
-        public uint GetLastInputCommand(ICommonSession session)
+        public uint GetLastInputCommand(IPlayerSession session)
         {
             return _lastProcessedInputCmd[session];
         }

Robust.Server/GameObjects/EntitySystems/MapLoaderSystem.cs

@@ -6,6 +6,7 @@ using System.IO;
 using System.Linq;
 using System.Numerics;
 using Robust.Server.Maps;
+using Robust.Shared.Collections;
 using Robust.Shared.ContentPack;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -732,7 +733,7 @@ public sealed class MapLoaderSystem : EntitySystem
             return;
 
         // get ents that the grids will bind to
-        var gridComps = new Entity<MapGridComponent>[yamlGrids.Count];
+        var gridComps = new MapGridComponent[yamlGrids.Count];
         var gridQuery = _serverEntityManager.GetEntityQuery<MapGridComponent>();
 
         // linear search for new grid comps
@@ -744,7 +745,7 @@ public sealed class MapLoaderSystem : EntitySystem
             // These should actually be new, pre-init
             DebugTools.Assert(gridComp.LifeStage == ComponentLifeStage.Added);
 
-            gridComps[gridComp.GridIndex] = new Entity<MapGridComponent>(uid, gridComp);
+            gridComps[gridComp.GridIndex] = gridComp;
         }
 
         for (var index = 0; index < yamlGrids.Count; index++)
@@ -763,18 +764,18 @@ public sealed class MapLoaderSystem : EntitySystem
             MappingDataNode yamlGridInfo = (MappingDataNode)yamlGrid["settings"];
             SequenceDataNode yamlGridChunks = (SequenceDataNode)yamlGrid["chunks"];
 
-            AllocateMapGrid(gridComp, yamlGridInfo);
-            var gridUid = gridComp.Owner;
+            var grid = AllocateMapGrid(gridComp, yamlGridInfo);
+            var gridUid = grid.Owner;
 
             foreach (var chunkNode in yamlGridChunks.Cast<MappingDataNode>())
             {
                 var (chunkOffsetX, chunkOffsetY) = _serManager.Read<Vector2i>(chunkNode["ind"]);
-                _serManager.Read(chunkNode, _context, instanceProvider: () => _mapSystem.GetOrAddChunk(gridUid, gridComp, chunkOffsetX, chunkOffsetY), notNullableOverride: true);
+                _serManager.Read(chunkNode, _context, instanceProvider: () => _mapSystem.GetOrAddChunk(gridUid, grid, chunkOffsetX, chunkOffsetY), notNullableOverride: true);
             }
         }
     }
 
-    private static void AllocateMapGrid(MapGridComponent gridComp, MappingDataNode yamlGridInfo)
+    private static MapGridComponent AllocateMapGrid(MapGridComponent gridComp, MappingDataNode yamlGridInfo)
     {
         // sane defaults
         ushort csz = 16;
@@ -794,6 +795,8 @@ public sealed class MapLoaderSystem : EntitySystem
 
         gridComp.ChunkSize = csz;
         gridComp.TileSize = tsz;
+
+        return gridComp;
     }
 
     private void StartupEntities(MapData data)

Robust.Server/GameObjects/EntitySystems/MapSystem.cs

@@ -66,8 +66,9 @@ namespace Robust.Server.GameObjects
 
         private void HandleGridEmpty(EntityUid uid, MapGridComponent component, EmptyGridEvent args)
         {
-            if (!_deleteEmptyGrids || TerminatingOrDeleted(uid) || HasComp<MapComponent>(uid))
-                return;
+            if (!_deleteEmptyGrids) return;
+            if (!EntityManager.EntityExists(uid)) return;
+            if (EntityManager.GetComponent<MetaDataComponent>(uid).EntityLifeStage >= EntityLifeStage.Terminating) return;
 
             MapManager.DeleteGrid(args.GridId);
         }

Robust.Server/GameObjects/EntitySystems/UserInterfaceSystem.cs

@@ -7,7 +7,7 @@ using Robust.Server.Player;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Utility;
 
 namespace Robust.Server.GameObjects
@@ -194,7 +194,7 @@ namespace Robust.Server.GameObjects
             return bui.SubscribedSessions.Count > 0;
         }
 
-        public bool SessionHasOpenUi(EntityUid uid, Enum uiKey, ICommonSession session, UserInterfaceComponent? ui = null)
+        public bool SessionHasOpenUi(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
         {
             if (!TryGetUi(uid, uiKey, out var bui, ui))
                 return false;
@@ -218,7 +218,7 @@ namespace Robust.Server.GameObjects
         public bool TrySetUiState(EntityUid uid,
             Enum uiKey,
             BoundUserInterfaceState state,
-            ICommonSession? session = null,
+            IPlayerSession? session = null,
             UserInterfaceComponent? ui = null,
             bool clearOverrides = true)
         {
@@ -284,7 +284,7 @@ namespace Robust.Server.GameObjects
 
         #region Open
 
-        public bool TryOpen(EntityUid uid, Enum uiKey, ICommonSession session, UserInterfaceComponent? ui = null)
+        public bool TryOpen(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
         {
             if (!TryGetUi(uid, uiKey, out var bui, ui))
                 return false;
@@ -319,7 +319,7 @@ namespace Robust.Server.GameObjects
         #endregion
 
         #region Close
-        public bool TryClose(EntityUid uid, Enum uiKey, ICommonSession session, UserInterfaceComponent? ui = null)
+        public bool TryClose(EntityUid uid, Enum uiKey, IPlayerSession session, UserInterfaceComponent? ui = null)
         {
             if (!TryGetUi(uid, uiKey, out var bui, ui))
                 return false;

Robust.Server/GameObjects/EntitySystems/ViewSubscriberSystem.cs

@@ -1,5 +1,5 @@
+using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
 
 namespace Robust.Server.GameObjects
 {
@@ -18,7 +18,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Subscribes the session to get PVS updates from the point of view of the specified entity.
         /// </summary>
-        public void AddViewSubscriber(EntityUid uid, ICommonSession session)
+        public void AddViewSubscriber(EntityUid uid, IPlayerSession session)
         {
             // If the entity doesn't have the component, it will be added.
             var viewSubscriber = EntityManager.EnsureComponent<ViewSubscriberComponent>(uid);
@@ -27,7 +27,7 @@ namespace Robust.Server.GameObjects
                 return; // Already subscribed, do nothing else.
 
             viewSubscriber.SubscribedSessions.Add(session);
-            session.ViewSubscriptions.Add(uid);
+            session.AddViewSubscription(uid);
 
             RaiseLocalEvent(uid, new ViewSubscriberAddedEvent(uid, session), true);
         }
@@ -35,7 +35,7 @@ namespace Robust.Server.GameObjects
         /// <summary>
         ///     Unsubscribes the session from getting PVS updates from the point of view of the specified entity.
         /// </summary>
-        public void RemoveViewSubscriber(EntityUid uid, ICommonSession session)
+        public void RemoveViewSubscriber(EntityUid uid, IPlayerSession session)
         {
             if(!EntityManager.TryGetComponent(uid, out ViewSubscriberComponent? viewSubscriber))
                 return; // Entity didn't have any subscriptions, do nothing.
@@ -43,7 +43,7 @@ namespace Robust.Server.GameObjects
             if (!viewSubscriber.SubscribedSessions.Remove(session))
                 return; // Session wasn't subscribed, do nothing.
 
-            session.ViewSubscriptions.Remove(uid);
+            session.RemoveViewSubscription(uid);
             RaiseLocalEvent(uid, new ViewSubscriberRemovedEvent(uid, session), true);
         }
 
@@ -51,7 +51,7 @@ namespace Robust.Server.GameObjects
         {
             foreach (var session in component.SubscribedSessions)
             {
-                session.ViewSubscriptions.Remove(uid);
+                session.RemoveViewSubscription(uid);
             }
         }
     }
@@ -62,9 +62,9 @@ namespace Robust.Server.GameObjects
     public sealed class ViewSubscriberAddedEvent : EntityEventArgs
     {
         public EntityUid View { get; }
-        public ICommonSession Subscriber { get; }
+        public IPlayerSession Subscriber { get; }
 
-        public ViewSubscriberAddedEvent(EntityUid view, ICommonSession subscriber)
+        public ViewSubscriberAddedEvent(EntityUid view, IPlayerSession subscriber)
         {
             View = view;
             Subscriber = subscriber;
@@ -78,9 +78,9 @@ namespace Robust.Server.GameObjects
     public sealed class ViewSubscriberRemovedEvent : EntityEventArgs
     {
         public EntityUid View { get; }
-        public ICommonSession Subscriber { get; }
+        public IPlayerSession Subscriber { get; }
 
-        public ViewSubscriberRemovedEvent(EntityUid view, ICommonSession subscriber)
+        public ViewSubscriberRemovedEvent(EntityUid view, IPlayerSession subscriber)
         {
             View = view;
             Subscriber = subscriber;

Robust.Server/GameObjects/EntitySystems/VisibilitySystem.cs

@@ -1,14 +1,13 @@
+using System;
 using Robust.Server.GameStates;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.GameObjects
 {
     public sealed class VisibilitySystem : EntitySystem
     {
         [Dependency] private readonly PvsSystem _pvs = default!;
-        [Dependency] private readonly IViewVariablesManager _vvManager = default!;
 
         private EntityQuery<TransformComponent> _xformQuery;
         private EntityQuery<MetaDataComponent> _metaQuery;
@@ -22,15 +21,6 @@ namespace Robust.Server.GameObjects
             _visiblityQuery = GetEntityQuery<VisibilityComponent>();
             SubscribeLocalEvent<EntParentChangedMessage>(OnParentChange);
             EntityManager.EntityInitialized += OnEntityInit;
-
-            _vvManager.GetTypeHandler<VisibilityComponent>()
-                .AddPath(nameof(VisibilityComponent.Layer), (_, comp) => comp.Layer, (uid, value, comp) =>
-                {
-                    if (!Resolve(uid, ref comp))
-                        return;
-
-                    SetLayer(uid, comp, value);
-                });
         }
 
         public override void Shutdown()
@@ -50,6 +40,12 @@ namespace Robust.Server.GameObjects
                 RefreshVisibility(uid, visibilityComponent: component);
         }
 
+        [Obsolete("Use overload that takes an EntityUid instead")]
+        public void AddLayer(VisibilityComponent component, int layer, bool refresh = true)
+        {
+            AddLayer(component.Owner, component, layer, refresh);
+        }
+
         public void RemoveLayer(EntityUid uid, VisibilityComponent component, int layer, bool refresh = true)
         {
             if ((layer & component.Layer) != layer)
@@ -61,6 +57,12 @@ namespace Robust.Server.GameObjects
                 RefreshVisibility(uid, visibilityComponent: component);
         }
 
+        [Obsolete("Use overload that takes an EntityUid instead")]
+        public void RemoveLayer(VisibilityComponent component, int layer, bool refresh = true)
+        {
+            RemoveLayer(component.Owner, component, layer, refresh);
+        }
+
         public void SetLayer(EntityUid uid, VisibilityComponent component, int layer, bool refresh = true)
         {
             if (component.Layer == layer)
@@ -72,6 +74,12 @@ namespace Robust.Server.GameObjects
                 RefreshVisibility(uid, visibilityComponent: component);
         }
 
+        [Obsolete("Use overload that takes an EntityUid instead")]
+        public void SetLayer(VisibilityComponent component, int layer, bool refresh = true)
+        {
+            SetLayer(component.Owner, component, layer, refresh);
+        }
+
         private void OnParentChange(ref EntParentChangedMessage ev)
         {
             RefreshVisibility(ev.Entity);
@@ -119,6 +127,12 @@ namespace Robust.Server.GameObjects
             }
         }
 
+        [Obsolete("Use overload that takes an EntityUid instead")]
+        public void RefreshVisibility(VisibilityComponent visibilityComponent)
+        {
+            RefreshVisibility(visibilityComponent.Owner, visibilityComponent);
+        }
+
         private int GetParentVisibilityMask(EntityUid uid, VisibilityComponent? visibilityComponent = null)
         {
             int visMask = 1; // apparently some content expects everything to have the first bit/flag set to true.

Robust.Server/GameObjects/IServerEntityNetworkManager.cs

@@ -1,10 +1,12 @@
+using System.Collections.Generic;
+using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
+using Robust.Shared.Timing;
 
 namespace Robust.Server.GameObjects
 {
     public interface IServerEntityNetworkManager : IEntityNetworkManager
     {
-        uint GetLastMessageSequence(ICommonSession session);
+        uint GetLastMessageSequence(IPlayerSession session);
     }
 }

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using JetBrains.Annotations;
 using Prometheus;
 using Robust.Server.Player;
@@ -14,7 +15,6 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Replays;
 using Robust.Shared.Timing;
@@ -131,7 +131,7 @@ namespace Robust.Server.GameObjects
 
         private readonly PriorityQueue<MsgEntity> _queue = new(new MessageSequenceComparer());
 
-        private readonly Dictionary<ICommonSession, uint> _lastProcessedSequencesCmd =
+        private readonly Dictionary<IPlayerSession, uint> _lastProcessedSequencesCmd =
             new();
 
         private bool _logLateMsgs;
@@ -162,7 +162,7 @@ namespace Robust.Server.GameObjects
             EntitiesCount.Set(Entities.Count);
         }
 
-        public uint GetLastMessageSequence(ICommonSession session)
+        public uint GetLastMessageSequence(IPlayerSession session)
         {
             return _lastProcessedSequencesCmd[session];
         }

Robust.Server/GameStates/IServerGameStateManager.cs

@@ -1,6 +1,6 @@
 using System;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 
 namespace Robust.Server.GameStates

Robust.Server/GameStates/PvsCollection.cs

@@ -8,7 +8,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 

Robust.Server/GameStates/PvsOverrideSystem.cs

@@ -1,5 +1,5 @@
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 
 namespace Robust.Server.GameStates;
 

Robust.Server/GameStates/PvsSystem.Ack.cs

@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 

Robust.Server/GameStates/PvsSystem.Dirty.cs

@@ -1,8 +1,8 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using Robust.Server.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Player;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -68,7 +68,7 @@ namespace Robust.Server.GameStates
             return true;
         }
 
-        public void CleanupDirty(IEnumerable<ICommonSession> sessions)
+        public void CleanupDirty(IEnumerable<IPlayerSession> sessions)
         {
             if (!CullingEnabled)
             {

Robust.Server/GameStates/PvsSystem.cs

@@ -15,7 +15,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Threading;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
@@ -35,16 +35,10 @@ internal sealed partial class PvsSystem : EntitySystem
     public const float ChunkSize = 8;
 
     // TODO make this a cvar. Make it in terms of seconds and tie it to tick rate?
-    // Main issue is that I CBF figuring out the logic for handling it changing mid-game.
     public const int DirtyBufferSize = 20;
     // Note: If a client has ping higher than TickBuffer / TickRate, then the server will treat every entity as if it
     // had entered PVS for the first time. Note that due to the PVS budget, this buffer is easily overwhelmed.
 
-    /// <summary>
-    /// See <see cref="CVars.NetForceAckThreshold"/>.
-    /// </summary>
-    public int ForceAckThreshold { get; private set; }
-
     /// <summary>
     /// Maximum number of pooled objects
     /// </summary>
@@ -145,7 +139,6 @@ internal sealed partial class PvsSystem : EntitySystem
 
         _configManager.OnValueChanged(CVars.NetPVS, SetPvs, true);
         _configManager.OnValueChanged(CVars.NetMaxUpdateRange, OnViewsizeChanged, true);
-        _configManager.OnValueChanged(CVars.NetForceAckThreshold, OnForceAckChanged, true);
 
         _serverGameStateManager.ClientAck += OnClientAck;
         _serverGameStateManager.ClientRequestFull += OnClientRequestFull;
@@ -163,7 +156,6 @@ internal sealed partial class PvsSystem : EntitySystem
 
         _configManager.UnsubValueChanged(CVars.NetPVS, SetPvs);
         _configManager.UnsubValueChanged(CVars.NetMaxUpdateRange, OnViewsizeChanged);
-        _configManager.UnsubValueChanged(CVars.NetForceAckThreshold, OnForceAckChanged);
 
         _serverGameStateManager.ClientAck -= OnClientAck;
         _serverGameStateManager.ClientRequestFull -= OnClientRequestFull;
@@ -207,7 +199,7 @@ internal sealed partial class PvsSystem : EntitySystem
         // return last acked to pool, but only if it is not still in the OverflowDictionary.
         if (sessionData.LastAcked != null && !sessionData.SentEntities.ContainsKey(sessionData.LastAcked.Value.Tick))
         {
-            DebugTools.Assert(!sessionData.SentEntities.Values.Contains(sessionData.LastAcked.Value.Data));
+            DebugTools.Assert(sessionData.SentEntities.Values.Contains(sessionData.LastAcked.Value.Data));
             _visSetPool.Return(sessionData.LastAcked.Value.Data);
         }
 
@@ -220,11 +212,6 @@ internal sealed partial class PvsSystem : EntitySystem
         _viewSize = obj * 2;
     }
 
-    private void OnForceAckChanged(int value)
-    {
-        ForceAckThreshold = value;
-    }
-
     private void SetPvs(bool value)
     {
         _seenAllEnts.Clear();
@@ -433,7 +420,7 @@ internal sealed partial class PvsSystem : EntitySystem
 
     #endregion
 
-    public (List<(int, IChunkIndexLocation)> , HashSet<int>[], EntityUid[][] viewers) GetChunks(ICommonSession[] sessions)
+    public (List<(int, IChunkIndexLocation)> , HashSet<int>[], EntityUid[][] viewers) GetChunks(IPlayerSession[] sessions)
     {
         var playerChunks = new HashSet<int>[sessions.Length];
         var viewerEntities = new EntityUid[sessions.Length][];
@@ -702,7 +689,7 @@ internal sealed partial class PvsSystem : EntitySystem
     }
 
     internal (List<EntityState>? updates, List<NetEntity>? deletions, List<NetEntity>? leftPvs, GameTick fromTick)
-        CalculateEntityStates(ICommonSession session,
+        CalculateEntityStates(IPlayerSession session,
             GameTick fromTick,
             GameTick toTick,
             (Dictionary<NetEntity, MetaDataComponent> metadata, RobustTree<NetEntity> tree)?[] chunks,
@@ -710,8 +697,8 @@ internal sealed partial class PvsSystem : EntitySystem
             EntityUid[] viewers)
     {
         DebugTools.Assert(session.Status == SessionStatus.InGame);
-        var newEntityBudget = _netConfigManager.GetClientCVar(session.Channel, CVars.NetPVSEntityBudget);
-        var enteredEntityBudget = _netConfigManager.GetClientCVar(session.Channel, CVars.NetPVSEntityEnterBudget);
+        var newEntityBudget = _netConfigManager.GetClientCVar(session.ConnectedClient, CVars.NetPVSEntityBudget);
+        var enteredEntityBudget = _netConfigManager.GetClientCVar(session.ConnectedClient, CVars.NetPVSEntityEnterBudget);
         var newEntityCount = 0;
         var enteredEntityCount = 0;
         var sessionData = PlayerData[session];
@@ -888,7 +875,7 @@ internal sealed partial class PvsSystem : EntitySystem
             return null;
 
         var tick = _gameTiming.CurTick;
-        var minSize = Math.Max(0, lastSent.Count - visibleEnts.Count);
+        var minSize = Math.Max(0, lastSent.Count - lastSent.Count);
         var leftView = new List<NetEntity>(minSize);
 
         foreach (var netEntity in lastSent.Keys)
@@ -1142,8 +1129,8 @@ internal sealed partial class PvsSystem : EntitySystem
             var query = EntityManager.AllEntityQueryEnumerator<MetaDataComponent>();
             while (query.MoveNext(out var uid, out var md))
             {
-                DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized, $"Entity {ToPrettyString(uid)} has not been initialized");
-                DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating, $"Entity {ToPrettyString(uid)} is/has been terminated");
+                DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized);
+                DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating);
                 if (md.EntityLastModifiedTick <= fromTick)
                     continue;
 
@@ -1178,10 +1165,10 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
                     if (!toSend.Add(uid) || !_metaQuery.TryGetComponent(uid, out var md))
                         continue;
 
-                    DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized, $"Entity {ToPrettyString(uid)} has not been initialized");
-                    DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating, $"Entity {ToPrettyString(uid)} is/has been terminated");
-                    DebugTools.Assert(md.EntityLastModifiedTick >= md.CreationTick, $"Entity {ToPrettyString(uid)} last modified tick is less than creation tick");
-                    DebugTools.Assert(md.EntityLastModifiedTick > fromTick, $"Entity {ToPrettyString(uid)} last modified tick is less than from tick");
+                    DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized);
+                    DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating);
+                    DebugTools.Assert(md.EntityLastModifiedTick >= md.CreationTick);
+                    DebugTools.Assert(md.EntityLastModifiedTick > fromTick);
 
                     var state = GetEntityState(player, uid, fromTick, md);
 
@@ -1205,10 +1192,10 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
                     if (!toSend.Add(uid) || !_metaQuery.TryGetComponent(uid, out var md))
                         continue;
 
-                    DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized, $"Entity {ToPrettyString(uid)} has not been initialized");
-                    DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating, $"Entity {ToPrettyString(uid)} is/has been terminated");
-                    DebugTools.Assert(md.EntityLastModifiedTick >= md.CreationTick, $"Entity {ToPrettyString(uid)} last modified tick is less than creation tick");
-                    DebugTools.Assert(md.EntityLastModifiedTick > fromTick, $"Entity {ToPrettyString(uid)} last modified tick is less than from tick");
+                    DebugTools.Assert(md.EntityLifeStage >= EntityLifeStage.Initialized);
+                    DebugTools.Assert(md.EntityLifeStage < EntityLifeStage.Terminating);
+                    DebugTools.Assert(md.EntityLastModifiedTick >= md.CreationTick);
+                    DebugTools.Assert(md.EntityLastModifiedTick > fromTick);
 
                     var state = GetEntityState(player, uid, fromTick, md);
                     if (!state.Empty)
@@ -1315,11 +1302,11 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
 
     private EntityUid[] GetSessionViewers(ICommonSession session)
     {
-        if (session.Status != SessionStatus.InGame)
+        if (session.Status != SessionStatus.InGame || session is not IPlayerSession sess)
             return Array.Empty<EntityUid>();
 
         // Fast path
-        if (session.ViewSubscriptions.Count == 0)
+        if (sess.ViewSubscriptionCount == 0)
         {
             if (session.AttachedEntity == null)
                 return Array.Empty<EntityUid>();
@@ -1331,7 +1318,11 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
         if (session.AttachedEntity != null)
             viewers.Add(session.AttachedEntity.Value);
 
-        viewers.UnionWith(session.ViewSubscriptions);
+        foreach (var uid in sess.ViewSubscriptions)
+        {
+            viewers.Add(uid);
+        }
+
         return viewers.ToArray();
     }
 
@@ -1421,7 +1412,7 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
 [ByRefEvent]
 public struct ExpandPvsEvent
 {
-    public readonly ICommonSession Session;
+    public readonly IPlayerSession Session;
 
     /// <summary>
     /// List of entities that will get added to this session's PVS set.
@@ -1434,7 +1425,7 @@ public struct ExpandPvsEvent
     /// </summary>
     public List<EntityUid>? RecursiveEntities;
 
-    public ExpandPvsEvent(ICommonSession session)
+    public ExpandPvsEvent(IPlayerSession session)
     {
         Session = session;
     }

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -26,7 +26,7 @@ using Prometheus;
 using Robust.Server.Replays;
 using Robust.Shared.Console;
 using Robust.Shared.Map.Components;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 
 namespace Robust.Server.GameStates
 {
@@ -168,7 +168,7 @@ Oldest acked clients: {string.Join(", ", players)}
         /// <inheritdoc />
         public void SendGameStateUpdate()
         {
-            var players = _playerManager.Sessions.Where(o => o.Status == SessionStatus.InGame).ToArray();
+            var players = _playerManager.ServerSessions.Where(o => o.Status == SessionStatus.InGame).ToArray();
 
             // Update entity positions in PVS chunks/collections
             // TODO disable processing if culling is disabled? Need to check if toggling PVS breaks anything.
@@ -224,7 +224,7 @@ Oldest acked clients: {string.Join(", ", players)}
             _pvs.CullDeletionHistory(oldestAck);
         }
 
-        private GameTick SendStates(ICommonSession[] players, PvsData? pvsData)
+        private GameTick SendStates(IPlayerSession[] players, PvsData? pvsData)
         {
             var inputSystem = _systemManager.GetEntitySystem<InputSystem>();
             var opts = new ParallelOptions {MaxDegreeOfParallelism = _parallelMgr.ParallelProcessCount};
@@ -265,7 +265,7 @@ Oldest acked clients: {string.Join(", ", players)}
             public (Dictionary<NetEntity, MetaDataComponent> metadata, RobustTree<NetEntity> tree)?[] ChunkCache;
         }
 
-        private PvsData? GetPVSData(ICommonSession[] players)
+        private PvsData? GetPVSData(IPlayerSession[] players)
         {
             var (chunks, playerChunks, viewerEntities) = _pvs.GetChunks(players);
             const int ChunkBatchSize = 2;
@@ -319,11 +319,11 @@ Oldest acked clients: {string.Join(", ", players)}
         private void SendStateUpdate(int i,
             PvsThreadResources resources,
             InputSystem inputSystem,
-            ICommonSession session,
+            IPlayerSession session,
             PvsData? pvsData,
             ref uint oldestAckValue)
         {
-            var channel = session.Channel;
+            var channel = session.ConnectedClient;
             var sessionData = _pvs.PlayerData[session];
             var lastAck = sessionData.LastReceivedAck;
             List<NetEntity>? leftPvs = null;
@@ -347,7 +347,7 @@ Oldest acked clients: {string.Join(", ", players)}
                 (entStates, deletions, fromTick) = _pvs.GetAllEntityStates(session, lastAck, _gameTiming.CurTick);
             }
 
-            var playerStates = _playerManager.GetPlayerStates(fromTick);
+            var playerStates = _playerManager.GetPlayerStates(lastAck);
 
             // lastAck varies with each client based on lag and such, we can't just make 1 global state and send it to everyone
             var lastInputCommand = inputSystem.GetLastInputCommand(session);
@@ -368,30 +368,11 @@ Oldest acked clients: {string.Join(", ", players)}
             stateUpdateMessage.State = state;
             stateUpdateMessage.CompressionContext = resources.CompressionContext;
 
+            _networkManager.ServerSendMessage(stateUpdateMessage, channel);
+
             // If the state is too big we let Lidgren send it reliably. This is to avoid a situation where a state is so
             // large that it (or part of it) consistently gets dropped. When we send reliably, we immediately update the
             // ack so that the next state will not also be huge.
-            //
-            // We also do this if the client's last ack is too old. This helps prevent things like the entity deletion
-            // history from becoming too bloated if a bad client fails to send acks for whatever reason.
-
-            if (_gameTiming.CurTick.Value > lastAck.Value + _pvs.ForceAckThreshold)
-            {
-                stateUpdateMessage.ForceSendReliably = true;
-
-                // Aside from the time shortly after connecting, this shouldn't be common. If it is happening.
-                // something is probably wrong (or we have a malicious client). Hence we log an error.
-                // If it is more frequent than I think, this can be downgraded to a warning.
-
-#if FULL_RELEASE
-                var connectedTime = (DateTime.UtcNow - session.ConnectedTime).TotalMinutes;
-                if (lastAck > GameTick.Zero && connectedTime > 1)
-                    _logger.Error($"Client {session} exceeded ack-tick threshold. Last ack: {lastAck}. Cur tick: {_gameTiming.CurTick}. Connect time: {connectedTime} minutes");
-#endif
-            }
-
-            _networkManager.ServerSendMessage(stateUpdateMessage, channel);
-
             if (stateUpdateMessage.ShouldSendReliably())
             {
                 sessionData.LastReceivedAck = _gameTiming.CurTick;

Robust.Server/Physics/GridFixtureSystem.cs

@@ -3,6 +3,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Numerics;
 using Robust.Server.Console;
+using Robust.Server.Player;
 using Robust.Shared;
 using Robust.Shared.Collections;
 using Robust.Shared.Configuration;
@@ -14,7 +15,7 @@ using Robust.Shared.Map.Components;
 using Robust.Shared.Maths;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Systems;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
@@ -91,7 +92,9 @@ namespace Robust.Server.Physics
 
         private void OnDebugRequest(RequestGridNodesMessage msg, EntitySessionEventArgs args)
         {
-            if (!_conGroup.CanCommand(args.SenderSession, ShowGridNodesCommand)) return;
+            var pSession = (PlayerSession) args.SenderSession;
+
+            if (!_conGroup.CanCommand(pSession, ShowGridNodesCommand)) return;
 
             AddDebugSubscriber(args.SenderSession);
         }
@@ -257,7 +260,7 @@ namespace Robust.Server.Physics
                 for (var i = 0; i < grids.Count - 1; i++)
                 {
                     var group = grids[i];
-                    var newGrid = _mapManager.CreateGridEntity(mapId);
+                    var newGrid = _mapManager.CreateGrid(mapId);
                     var newGridUid = newGrid.Owner;
                     var newGridXform = xformQuery.GetComponent(newGridUid);
                     newGrids[i] = newGridUid;
@@ -284,7 +287,7 @@ namespace Robust.Server.Physics
                         }
                     }
 
-                    newGrid.Comp.SetTiles(tileData);
+                    newGrid.SetTiles(tileData);
                     DebugTools.Assert(_mapManager.IsGrid(newGridUid), "A split grid had no tiles?");
 
                     // Set tiles on new grid + update anchored entities

Robust.Server/Placement/PlacementManager.cs

@@ -15,7 +15,6 @@ using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Placement;
-using Robust.Shared.Player;
 using Robust.Shared.Prototypes;
 
 namespace Robust.Server.Placement
@@ -200,11 +199,11 @@ namespace Robust.Server.Placement
             }
             else if (tileType != 0) // create a new grid
             {
-                var newGrid = _mapManager.CreateGridEntity(coordinates.GetMapId(_entityManager));
-                var newGridXform = _entityManager.GetComponent<TransformComponent>(newGrid);
-                newGridXform.WorldPosition = coordinates.Position - newGrid.Comp.TileSizeHalfVector; // assume bottom left tile origin
-                var tilePos = newGrid.Comp.WorldToTile(coordinates.Position);
-                newGrid.Comp.SetTile(tilePos, new Tile(tileType));
+                var newGrid = _mapManager.CreateGrid(coordinates.GetMapId(_entityManager));
+                var newGridXform = _entityManager.GetComponent<TransformComponent>(newGrid.Owner);
+                newGridXform.WorldPosition = coordinates.Position - newGrid.TileSizeHalfVector; // assume bottom left tile origin
+                var tilePos = newGrid.WorldToTile(coordinates.Position);
+                newGrid.SetTile(tilePos, new Tile(tileType));
 
                 var placementEraseEvent = new PlacementTileEvent(tileType, coordinates, placingUserId);
                 _entityManager.EventBus.RaiseEvent(EventSource.Local, placementEraseEvent);

Robust.Server/Player/IPlayerManager.cs

@@ -1,12 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using Robust.Shared.Enums;
+using Robust.Shared.GameStates;
 using Robust.Shared.Input;
+using Robust.Shared.Map;
+using Robust.Shared.Network;
 using Robust.Shared.Player;
+using Robust.Shared.Players;
+using Robust.Shared.Timing;
 
-namespace Robust.Server.Player;
-
-/// <summary>
-///     Manages each players session when connected to the server.
-/// </summary>
-public interface IPlayerManager : ISharedPlayerManager
+namespace Robust.Server.Player
 {
-    BoundKeyMap KeyMap { get; }
-}
+    /// <summary>
+    ///     Manages each players session when connected to the server.
+    /// </summary>
+    public interface IPlayerManager : ISharedPlayerManager
+    {
+        BoundKeyMap KeyMap { get; }
+
+        /// <summary>
+        /// Same as the common sessions, but the server version.
+        /// </summary>
+        IEnumerable<IPlayerSession> ServerSessions { get; }
+
+        /// <summary>
+        ///     Raised when the <see cref="SessionStatus" /> of a <see cref="IPlayerSession" /> is changed.
+        /// </summary>
+        event EventHandler<SessionStatusEventArgs> PlayerStatusChanged;
+
+        /// <summary>
+        ///     Initializes the manager.
+        /// </summary>
+        /// <param name="maxPlayers">Maximum number of players that can connect to this server at one time.</param>
+        void Initialize(int maxPlayers);
+
+        void Shutdown();
+
+        bool TryGetSessionByUsername(string username, [NotNullWhen(true)] out IPlayerSession? session);
+
+        /// <summary>
+        ///     Returns the client session of the networkId.
+        /// </summary>
+        /// <returns></returns>
+        IPlayerSession GetSessionByUserId(NetUserId index);
+
+        IPlayerSession GetSessionByChannel(INetChannel channel);
+
+        bool TryGetSessionByChannel(INetChannel channel, [NotNullWhen(true)] out IPlayerSession? session);
+
+        bool TryGetSessionById(NetUserId userId, [NotNullWhen(true)] out IPlayerSession? session);
+
+        /// <summary>
+        ///     Checks to see if a PlayerIndex is a valid session.
+        /// </summary>
+        bool ValidSessionId(NetUserId index);
+
+        IPlayerData GetPlayerData(NetUserId userId);
+        bool TryGetPlayerData(NetUserId userId, [NotNullWhen(true)] out IPlayerData? data);
+        bool TryGetPlayerDataByUsername(string userName, [NotNullWhen(true)] out IPlayerData? data);
+        bool HasPlayerData(NetUserId userId);
+
+        /// <summary>
+        ///     Tries to get the user ID of the user with the specified username.
+        /// </summary>
+        /// <remarks>
+        ///     This only works if this user has already connected once before during this server run.
+        ///     It does still work if the user has since disconnected.
+        /// </remarks>
+        bool TryGetUserId(string userName, out NetUserId userId);
+
+        IEnumerable<IPlayerData> GetAllPlayerData();
+
+
+        [Obsolete]
+        void DetachAll();
+        [Obsolete("Use player Filter or Inline me!")]
+        List<IPlayerSession> GetPlayersInRange(MapCoordinates worldPos, int range);
+        [Obsolete("Use player Filter or Inline me!")]
+        List<IPlayerSession> GetPlayersInRange(EntityCoordinates worldPos, int range);
+        [Obsolete("Use player Filter or Inline me!")]
+        List<IPlayerSession> GetPlayersBy(Func<IPlayerSession, bool> predicate);
+        [Obsolete("Use player Filter or Inline me!")]
+        List<IPlayerSession> GetAllPlayers();
+        List<PlayerState>? GetPlayerStates(GameTick fromTick);
+    }
+}

Robust.Server/Player/IPlayerSession.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Network;
+using Robust.Shared.Player;
+using Robust.Shared.Players;
+
+namespace Robust.Server.Player
+{
+    public interface IPlayerSession : ICommonSession
+    {
+        DateTime ConnectedTime { get; }
+
+        event EventHandler<SessionStatusEventArgs> PlayerStatusChanged;
+
+        void JoinGame();
+
+        LoginType AuthType { get; }
+
+        /// <summary>
+        ///     Attaches this player to an entity.
+        ///     NOTE: The content pack almost certainly has an alternative for this.
+        ///     Do not call this directly for most content code.
+        /// </summary>
+        /// <param name="entity">The entity to attach to.</param>
+        [Obsolete("Use ActorSystem.Attach() instead.")]
+        void AttachToEntity(EntityUid? entity);
+
+        /// <summary>
+        ///     Attaches this player to an entity.
+        ///     NOTE: The content pack almost certainly has an alternative for this.
+        ///     Do not call this directly for most content code.
+        /// </summary>
+        /// <param name="uid">The entity to attach to.</param>
+        [Obsolete("Use ActorSystem.Attach() instead.")]
+        void AttachToEntity(EntityUid uid);
+
+        /// <summary>
+        ///     Detaches this player from an entity.
+        ///     NOTE: The content pack almost certainly has an alternative for this.
+        ///     Do not call this directly for most content code.
+        /// </summary>
+        [Obsolete("Use ActorSystem.Detach() instead.")]
+        void DetachFromEntity();
+        void OnConnect();
+        void OnDisconnect();
+
+        IReadOnlySet<EntityUid> ViewSubscriptions { get; }
+
+        int ViewSubscriptionCount { get; }
+
+        /// <summary>
+        ///     Persistent data for this player.
+        /// </summary>
+        IPlayerData Data { get; }
+
+        /// <summary>
+        ///     Internal method to set <see cref="ICommonSession.AttachedEntity"/> and update the player's status.
+        ///     Do NOT use this unless you know what you're doing, you probably want <see cref="AttachToEntity"/>
+        ///     and <see cref="DetachFromEntity"/> instead.
+        /// </summary>
+        internal void SetAttachedEntity(EntityUid? entity);
+
+        /// <summary>
+        ///     Internal method to add an entity Uid to <see cref="ViewSubscriptions"/>.
+        ///     Do NOT use this outside of <see cref="ViewSubscriberSystem"/>.
+        /// </summary>
+        internal void AddViewSubscription(EntityUid eye);
+
+        /// <summary>
+        ///     Internal method to remove an entity Uid from <see cref="ViewSubscriptions"/>.
+        ///     Do NOT use this outside of <see cref="ViewSubscriberSystem"/>.
+        /// </summary>
+        internal void RemoveViewSubscription(EntityUid eye);
+    }
+}

Robust.Server/Player/PlayerData.cs

@@ -0,0 +1,24 @@
+using Robust.Shared.Network;
+using Robust.Shared.Player;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Server.Player
+{
+    sealed class PlayerData : IPlayerData
+    {
+        public PlayerData(NetUserId userId, string userName)
+        {
+            UserId = userId;
+            UserName = userName;
+        }
+
+        [ViewVariables]
+        public NetUserId UserId { get; }
+
+        [ViewVariables]
+        public string UserName { get; }
+
+        [ViewVariables]
+        public object? ContentDataUncast { get; set; }
+    }
+}

Robust.Server/Player/PlayerManager.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Prometheus;
 using Robust.Server.Configuration;
@@ -11,19 +12,22 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
+using Robust.Shared.Map;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
 using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Reflection;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;
+using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.Player
 {
     /// <summary>
     ///     This class will manage connected player sessions.
     /// </summary>
-    internal sealed class PlayerManager : SharedPlayerManager, IPlayerManager
+    public sealed class PlayerManager : IPlayerManager
     {
         private static readonly Gauge PlayerCountMetric = Metrics
             .CreateGauge("robust_player_count", "Number of players on the server.");
@@ -37,13 +41,79 @@ namespace Robust.Server.Player
 
         public BoundKeyMap KeyMap { get; private set; } = default!;
 
+        private GameTick _lastStateUpdate;
+
+        private readonly ReaderWriterLockSlim _sessionsLock = new();
+
+        /// <summary>
+        ///     Active sessions of connected clients to the server.
+        /// </summary>
+        [ViewVariables]
+        private readonly Dictionary<NetUserId, PlayerSession> _sessions = new();
+
+        [ViewVariables]
+        private readonly Dictionary<NetUserId, PlayerData> _playerData = new();
+
+        [ViewVariables]
+        private readonly Dictionary<string, NetUserId> _userIdMap = new();
+
         /// <inheritdoc />
-        public override void Initialize(int maxPlayers)
+        public IEnumerable<ICommonSession> NetworkedSessions => Sessions;
+
+        /// <inheritdoc />
+        public IEnumerable<ICommonSession> Sessions
+        {
+            get
+            {
+                _sessionsLock.EnterReadLock();
+                try
+                {
+                    return _sessions.Values;
+                }
+                finally
+                {
+                    _sessionsLock.ExitReadLock();
+                }
+            }
+        }
+
+        public IEnumerable<IPlayerSession> ServerSessions => Sessions.Cast<IPlayerSession>();
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public int PlayerCount
+        {
+            get
+            {
+                _sessionsLock.EnterReadLock();
+                try
+                {
+                    return _sessions.Count;
+                }
+                finally
+                {
+                    _sessionsLock.ExitReadLock();
+                }
+            }
+        }
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public int MaxPlayers { get; private set; } = 32;
+
+        public ICommonSession? LocalSession => null;
+
+        /// <inheritdoc />
+        public event EventHandler<SessionStatusEventArgs>? PlayerStatusChanged;
+
+        /// <inheritdoc />
+        public void Initialize(int maxPlayers)
         {
-            base.Initialize(maxPlayers);
             KeyMap = new BoundKeyMap(_reflectionManager);
             KeyMap.PopulateKeyFunctionsMap();
 
+            MaxPlayers = maxPlayers;
+
             _network.RegisterNetMessage<MsgPlayerListReq>(HandlePlayerListReq);
             _network.RegisterNetMessage<MsgPlayerList>();
             _network.RegisterNetMessage<MsgSyncTimeBase>();
@@ -53,9 +123,8 @@ namespace Robust.Server.Player
             _network.Disconnect += EndSession;
         }
 
-        public override void Shutdown()
+        public void Shutdown()
         {
-            base.Shutdown();
             KeyMap = default!;
 
             _network.Connecting -= OnConnecting;
@@ -63,6 +132,250 @@ namespace Robust.Server.Player
             _network.Disconnect -= EndSession;
         }
 
+        public bool TryGetSessionByUsername(string username, [NotNullWhen(true)] out IPlayerSession? session)
+        {
+            if (!_userIdMap.TryGetValue(username, out var userId))
+            {
+                session = null;
+                return false;
+            }
+
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                if (_sessions.TryGetValue(userId, out var iSession))
+                {
+                    session = iSession;
+                    return true;
+                }
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+
+
+            session = null;
+            return false;
+        }
+
+        IPlayerSession IPlayerManager.GetSessionByChannel(INetChannel channel) => GetSessionByChannel(channel);
+        public bool TryGetSessionByChannel(INetChannel channel, [NotNullWhen(true)] out IPlayerSession? session)
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                // Should only be one session per client. Returns that session, in theory.
+                if (_sessions.TryGetValue(channel.UserId, out var concrete))
+                {
+                    session = concrete;
+                    return true;
+                }
+
+                session = null;
+                return false;
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        private PlayerSession GetSessionByChannel(INetChannel channel)
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                // Should only be one session per client. Returns that session, in theory.
+                return _sessions[channel.UserId];
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        /// <inheritdoc />
+        public IPlayerSession GetSessionByUserId(NetUserId index)
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                return _sessions[index];
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        public bool ValidSessionId(NetUserId index)
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                return _sessions.ContainsKey(index);
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        public bool TryGetSessionById(NetUserId userId, [NotNullWhen(true)] out IPlayerSession? session)
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                if (_sessions.TryGetValue(userId, out var playerSession))
+                {
+                    session = playerSession;
+                    return true;
+                }
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+            session = default;
+            return false;
+        }
+
+        /// <summary>
+        ///     Causes all sessions to switch from the lobby to the the game.
+        /// </summary>
+        [Obsolete]
+        public void SendJoinGameToAll()
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                foreach (var s in _sessions.Values)
+                {
+                    s.JoinGame();
+                }
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        public bool TryGetUserId(string userName, out NetUserId userId)
+        {
+            return _userIdMap.TryGetValue(userName, out userId);
+        }
+
+        public IEnumerable<IPlayerData> GetAllPlayerData()
+        {
+            return _playerData.Values;
+        }
+
+        /// <summary>
+        ///     Causes all sessions to detach from their entity.
+        /// </summary>
+        [Obsolete]
+        public void DetachAll()
+        {
+            _sessionsLock.EnterReadLock();
+            try
+            {
+                foreach (var s in _sessions.Values)
+                {
+                    s.DetachFromEntity();
+                }
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
+        /// <summary>
+        ///     Gets all players inside of a circle.
+        /// </summary>
+        /// <param name="worldPos">Position of the circle in world-space.</param>
+        /// <param name="range">Radius of the circle in world units.</param>
+        /// <returns></returns>
+        [Obsolete("Use player Filter or Inline me!")]
+        public List<IPlayerSession> GetPlayersInRange(MapCoordinates worldPos, int range)
+        {
+            return Filter.Empty()
+                .AddInRange(worldPos, range)
+                .Recipients
+                .Cast<IPlayerSession>()
+                .ToList();
+        }
+
+        /// <summary>
+        ///     Gets all players inside of a circle.
+        /// </summary>
+        /// <param name="worldPos">Position of the circle in world-space.</param>
+        /// <param name="range">Radius of the circle in world units.</param>
+        /// <returns></returns>
+        [Obsolete("Use player Filter or Inline me!")]
+        public List<IPlayerSession> GetPlayersInRange(EntityCoordinates worldPos, int range)
+        {
+            return Filter.Empty()
+                .AddInRange(worldPos.ToMap(_entityManager), range)
+                .Recipients
+                .Cast<IPlayerSession>()
+                .ToList();
+        }
+
+        [Obsolete("Use player Filter or Inline me!")]
+        public List<IPlayerSession> GetPlayersBy(Func<IPlayerSession, bool> predicate)
+        {
+            return Filter.Empty()
+                .AddWhere((session => predicate((IPlayerSession)session)))
+                .Recipients
+                .Cast<IPlayerSession>()
+                .ToList();
+        }
+
+        /// <summary>
+        ///     Gets all players in the server.
+        /// </summary>
+        /// <returns></returns>
+        [Obsolete("Use player Filter or Inline me!")]
+        public List<IPlayerSession> GetAllPlayers()
+        {
+            return ServerSessions.ToList();
+        }
+
+        /// <summary>
+        ///     Gets all player states in the server.
+        /// </summary>
+        /// <param name="fromTick"></param>
+        /// <returns></returns>
+        public List<PlayerState>? GetPlayerStates(GameTick fromTick)
+        {
+            if (_lastStateUpdate < fromTick)
+            {
+                return null;
+            }
+
+            _sessionsLock.EnterReadLock();
+            try
+            {
+#if FULL_RELEASE
+                return _sessions.Values
+                    .Select(s => s.PlayerState)
+                    .ToList();
+#else
+                // Integration tests need to clone data before "sending" it to the client. Otherwise they reference the
+                // same object.
+                return _sessions.Values
+                    .Select(s => s.PlayerState.Clone())
+                    .ToList();
+#endif
+            }
+            finally
+            {
+                _sessionsLock.ExitReadLock();
+            }
+        }
+
         private Task OnConnecting(NetConnectingArgs args)
         {
             if (PlayerCount >= _baseServer.MaxPlayers)
@@ -80,10 +393,30 @@ namespace Robust.Server.Player
         /// <param name="args"></param>
         private void NewSession(object? sender, NetChannelArgs args)
         {
-            var session = CreateAndAddSession(args.Channel.UserId, args.Channel.UserName);
-            session.Channel = args.Channel;
+            if (!_playerData.TryGetValue(args.Channel.UserId, out var data))
+            {
+                data = new PlayerData(args.Channel.UserId, args.Channel.UserName);
+                _playerData.Add(args.Channel.UserId, data);
+            }
+
+            _userIdMap[args.Channel.UserName] = args.Channel.UserId;
+
+            var session = new PlayerSession(this, args.Channel, data);
+
+            session.PlayerStatusChanged += (_, sessionArgs) => OnPlayerStatusChanged(session, sessionArgs.OldStatus, sessionArgs.NewStatus);
+
+            _sessionsLock.EnterWriteLock();
+            try
+            {
+                _sessions.Add(args.Channel.UserId, session);
+            }
+            finally
+            {
+                _sessionsLock.ExitWriteLock();
+            }
 
             PlayerCountMetric.Set(PlayerCount);
+
             // Synchronize base time.
             var msgTimeBase = new MsgSyncTimeBase();
             (msgTimeBase.Time, msgTimeBase.Tick) = _timing.TimeBase;
@@ -92,6 +425,11 @@ namespace Robust.Server.Player
             _cfg.SyncConnectingClient(args.Channel);
         }
 
+        private void OnPlayerStatusChanged(IPlayerSession session, SessionStatus oldStatus, SessionStatus newStatus)
+        {
+            PlayerStatusChanged?.Invoke(this, new SessionStatusEventArgs(session, oldStatus, newStatus));
+        }
+
         /// <summary>
         ///     Ends a clients session, and disconnects them.
         /// </summary>
@@ -103,19 +441,20 @@ namespace Robust.Server.Player
             }
 
             // make sure nothing got messed up during the life of the session
-            DebugTools.Assert(session.Channel == args.Channel);
+            DebugTools.Assert(session.ConnectedClient == args.Channel);
 
-            SetStatus(session, SessionStatus.Disconnected);
-            if (session.AttachedEntity != null)
-                EntManager.System<ActorSystem>().Detach(session.AttachedEntity.Value);
-
-            var viewSys = EntManager.System<ViewSubscriberSystem>();
-            foreach (var eye in session.ViewSubscriptions.ToArray())
+            //Detach the entity and (don't)delete it.
+            session.OnDisconnect();
+            _sessionsLock.EnterWriteLock();
+            try
             {
-                viewSys.RemoveViewSubscriber(eye, session);
+                _sessions.Remove(session.UserId);
+            }
+            finally
+            {
+                _sessionsLock.ExitWriteLock();
             }
 
-            RemoveSession(session.UserId);
             PlayerCountMetric.Set(PlayerCount);
             Dirty();
         }
@@ -130,18 +469,17 @@ namespace Robust.Server.Player
             // This is done before the packet is built, so that the client
             // can see themselves Connected.
             var session = GetSessionByChannel(channel);
-            session.ConnectedTime = DateTime.UtcNow;
-            SetStatus(session, SessionStatus.Connected);
+            session.OnConnect();
 
-            var list = new List<SessionState>();
+            var list = new List<PlayerState>();
             foreach (var client in players)
             {
-                var info = new SessionState
+                var info = new PlayerState
                 {
                     UserId = client.UserId,
                     Name = client.Name,
                     Status = client.Status,
-                    Ping = client.Channel!.Ping
+                    Ping = client.ConnectedClient.Ping
                 };
                 list.Add(info);
             }
@@ -151,7 +489,46 @@ namespace Robust.Server.Player
             channel.SendMessage(netMsg);
         }
 
-        public override bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
+        public void Dirty()
+        {
+            _lastStateUpdate = _timing.CurTick;
+        }
+
+        public IPlayerData GetPlayerData(NetUserId userId)
+        {
+            return _playerData[userId];
+        }
+
+        public bool TryGetPlayerData(NetUserId userId, [NotNullWhen(true)] out IPlayerData? data)
+        {
+            if (_playerData.TryGetValue(userId, out var playerData))
+            {
+                data = playerData;
+                return true;
+            }
+            data = default;
+            return false;
+        }
+
+        public bool TryGetPlayerDataByUsername(string userName, [NotNullWhen(true)] out IPlayerData? data)
+        {
+            if (!_userIdMap.TryGetValue(userName, out var userId))
+            {
+                data = null;
+                return false;
+            }
+
+            // PlayerData is initialized together with the _userIdMap so we can trust that it'll be present.
+            data = _playerData[userId];
+            return true;
+        }
+
+        public bool HasPlayerData(NetUserId userId)
+        {
+            return _playerData.ContainsKey(userId);
+        }
+
+        public bool TryGetSessionByEntity(EntityUid uid, [NotNullWhen(true)] out ICommonSession? session)
         {
             if (!_entityManager.TryGetComponent(uid, out ActorComponent? actor))
             {
@@ -163,4 +540,18 @@ namespace Robust.Server.Player
             return true;
         }
     }
+
+    public sealed class SessionStatusEventArgs : EventArgs
+    {
+        public SessionStatusEventArgs(IPlayerSession session, SessionStatus oldStatus, SessionStatus newStatus)
+        {
+            Session = session;
+            OldStatus = oldStatus;
+            NewStatus = newStatus;
+        }
+
+        public IPlayerSession Session { get; }
+        public SessionStatus OldStatus { get; }
+        public SessionStatus NewStatus { get; }
+    }
 }

Robust.Server/Player/PlayerSession.cs

@@ -0,0 +1,224 @@
+using System;
+using System.Collections.Generic;
+using Robust.Server.GameObjects;
+using Robust.Shared.Enums;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
+using Robust.Shared.IoC;
+using Robust.Shared.Log;
+using Robust.Shared.Network;
+using Robust.Shared.Player;
+using Robust.Shared.Players;
+using Robust.Shared.ViewVariables;
+
+namespace Robust.Server.Player
+{
+    /// <summary>
+    /// This is the session of a connected client.
+    /// </summary>
+    internal sealed class PlayerSession : IPlayerSession
+    {
+        private readonly PlayerManager _playerManager;
+        public readonly PlayerState PlayerState;
+        private readonly HashSet<EntityUid> _viewSubscriptions = new();
+
+        public PlayerSession(PlayerManager playerManager, INetChannel client, PlayerData data)
+        {
+            _playerManager = playerManager;
+            UserId = client.UserId;
+            Name = client.UserName;
+            _data = data;
+
+            PlayerState = new PlayerState
+            {
+                UserId = client.UserId,
+            };
+
+            ConnectedClient = client;
+
+            UpdatePlayerState();
+        }
+
+        [ViewVariables] public IReadOnlySet<EntityUid> ViewSubscriptions => _viewSubscriptions;
+        public int ViewSubscriptionCount => _viewSubscriptions.Count;
+
+        [ViewVariables] public INetChannel ConnectedClient { get; }
+
+        /// <inheritdoc />
+        [ViewVariables] public EntityUid? AttachedEntity { get; set; }
+
+        private SessionStatus _status = SessionStatus.Connecting;
+
+        [ViewVariables]
+        internal string Name { get; set; }
+
+        /// <inheritdoc />
+        string ICommonSession.Name
+        {
+            get => this.Name;
+            set => this.Name = value;
+        }
+
+        [ViewVariables]
+        internal short Ping
+        {
+            get => ConnectedClient.Ping;
+            set => throw new NotSupportedException();
+        }
+
+        short ICommonSession.Ping
+        {
+            get => this.Ping;
+            set => this.Ping = value;
+        }
+
+        [ViewVariables]
+        internal SessionStatus Status
+        {
+            get => _status;
+            set
+            {
+                if (_status == value)
+                    return;
+
+                var old = _status;
+                _status = value;
+                UpdatePlayerState();
+
+                PlayerStatusChanged?.Invoke(this, new SessionStatusEventArgs(this, old, value));
+            }
+        }
+
+        /// <inheritdoc />
+        SessionStatus ICommonSession.Status
+        {
+            get => this.Status;
+            set => this.Status = value;
+        }
+
+        /// <inheritdoc />
+        public DateTime ConnectedTime { get; private set; }
+
+        [ViewVariables(VVAccess.ReadWrite)]
+        public int VisibilityMask { get; set; } = 1;
+
+        /// <inheritdoc />
+        [ViewVariables]
+        public NetUserId UserId { get; }
+
+        private readonly PlayerData _data;
+
+        [ViewVariables] public IPlayerData Data => _data;
+
+        /// <inheritdoc />
+        public event EventHandler<SessionStatusEventArgs>? PlayerStatusChanged;
+
+        /// <inheritdoc />
+        [Obsolete("Use ActorSystem.Attach() instead.")]
+        public void AttachToEntity(EntityUid? entity)
+        {
+            EntitySystem.Get<ActorSystem>().Attach(entity, this);
+        }
+
+        /// <inheritdoc />
+        [Obsolete("Use ActorSystem.Attach() instead.")]
+        public void AttachToEntity(EntityUid uid)
+        {
+            EntitySystem.Get<ActorSystem>().Attach(uid, this);
+        }
+
+        /// <inheritdoc />
+        [Obsolete("Use ActorSystem.Detach() instead.")]
+        public void DetachFromEntity()
+        {
+            if (AttachedEntity == null)
+                return;
+
+            if (IoCManager.Resolve<IEntityManager>().Deleted(AttachedEntity!.Value))
+            {
+                Logger.Error($"Player \"{this}\" was attached to an entity that was deleted. THIS SHOULD NEVER HAPPEN, BUT DOES.");
+                // We can't contact ActorSystem because trying to fire an entity event would crash.
+                // Work around it.
+                AttachedEntity = null;
+                UpdatePlayerState();
+                return;
+            }
+
+            EntitySystem.Get<ActorSystem>().Detach(AttachedEntity.Value);
+        }
+
+        /// <inheritdoc />
+        public void OnConnect()
+        {
+            ConnectedTime = DateTime.UtcNow;
+            Status = SessionStatus.Connected;
+            UpdatePlayerState();
+        }
+
+        /// <inheritdoc />
+        public void OnDisconnect()
+        {
+            Status = SessionStatus.Disconnected;
+
+            UnsubscribeAllViews();
+            DetachFromEntity();
+            UpdatePlayerState();
+        }
+
+        /// <summary>
+        ///     Causes the session to switch from the lobby to the game.
+        /// </summary>
+        public void JoinGame()
+        {
+            if (ConnectedClient == null || Status == SessionStatus.InGame)
+                return;
+
+            Status = SessionStatus.InGame;
+            UpdatePlayerState();
+        }
+
+        public LoginType AuthType => ConnectedClient.AuthType;
+
+        /// <inheritdoc />
+        void IPlayerSession.SetAttachedEntity(EntityUid? entity)
+        {
+            AttachedEntity = entity;
+            UpdatePlayerState();
+        }
+
+        void IPlayerSession.AddViewSubscription(EntityUid eye)
+        {
+            _viewSubscriptions.Add(eye);
+        }
+
+        void IPlayerSession.RemoveViewSubscription(EntityUid eye)
+        {
+            _viewSubscriptions.Remove(eye);
+        }
+
+        private void UnsubscribeAllViews()
+        {
+            var viewSubscriberSystem = EntitySystem.Get<ViewSubscriberSystem>();
+
+            foreach (var eye in _viewSubscriptions)
+            {
+                viewSubscriberSystem.RemoveViewSubscriber(eye, this);
+            }
+        }
+
+        private void UpdatePlayerState()
+        {
+            PlayerState.Status = Status;
+            PlayerState.Name = Name;
+            PlayerState.ControlledEntity = IoCManager.Resolve<IEntityManager>().GetNetEntity(AttachedEntity);
+
+            _playerManager.Dirty();
+        }
+
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return Name;
+        }
+    }
+}

Robust.Server/Scripting/ScriptHost.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics.CodeAnalysis;
@@ -19,7 +20,6 @@ using Robust.Shared.Log;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
 using Robust.Shared.Reflection;
 using Robust.Shared.Scripting;
 using Robust.Shared.Utility;
@@ -38,7 +38,7 @@ namespace Robust.Server.Scripting
         [Dependency] private readonly IDependencyCollection _dependencyCollection = default!;
         [Dependency] private readonly ILogManager _logManager = default!;
 
-        readonly Dictionary<ICommonSession, Dictionary<int, ScriptInstance>> _instances =
+        readonly Dictionary<IPlayerSession, Dictionary<int, ScriptInstance>> _instances =
             new();
 
         private ISawmill _sawmill = default!;

Robust.Server/ServerIoC.cs

@@ -22,7 +22,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Replays;

Robust.Server/ServerStatus/DefaultMagicAczProvider.cs

@@ -34,12 +34,12 @@ public sealed class DefaultMagicAczProvider : IMagicAczProvider
         var inputPass = graph.Input;
 
         var contentDir = FindContentRootPath(_deps);
-        await RobustSharedPackaging.WriteContentAssemblies(
+        await RobustClientPackaging.WriteContentAssemblies(
             inputPass,
             contentDir,
             binFolderPath,
             assemblyNames,
-            cancel: cancel);
+            cancel);
 
         await RobustClientPackaging.WriteClientResources(contentDir, inputPass, cancel);
 

Robust.Server/Toolshed/Commands/Players/ActorCommand.cs

@@ -1,8 +1,8 @@
 using System.Collections.Generic;
 using System.Linq;
 using Robust.Server.GameObjects;
+using Robust.Server.Player;
 using Robust.Shared.GameObjects;
-using Robust.Shared.Player;
 using Robust.Shared.Toolshed;
 
 namespace Robust.Server.Toolshed.Commands.Players;
@@ -17,7 +17,7 @@ public sealed class ActorCommand : ToolshedCommand
     }
 
     [CommandImplementation("session")]
-    public IEnumerable<ICommonSession> Session([PipedArgument] IEnumerable<EntityUid> input)
+    public IEnumerable<IPlayerSession> Session([PipedArgument] IEnumerable<EntityUid> input)
     {
         return input.Where(HasComp<ActorComponent>).Select(x => Comp<ActorComponent>(x).PlayerSession);
     }

Robust.Server/Toolshed/Commands/Players/PlayersCommand.cs

@@ -7,7 +7,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Errors;
 using Robust.Shared.Utility;
@@ -20,18 +20,18 @@ public sealed class PlayerCommand : ToolshedCommand
     [Dependency] private readonly IPlayerManager _playerManager = default!;
 
     [CommandImplementation("list")]
-    public IEnumerable<ICommonSession> Players()
-        => _playerManager.Sessions;
+    public IEnumerable<IPlayerSession> Players()
+        => _playerManager.ServerSessions;
 
     [CommandImplementation("self")]
-    public ICommonSession Self([CommandInvocationContext] IInvocationContext ctx)
+    public IPlayerSession Self([CommandInvocationContext] IInvocationContext ctx)
     {
         if (ctx.Session is null)
         {
             ctx.ReportError(new NotForServerConsoleError());
         }
 
-        return ctx.Session!;
+        return (IPlayerSession)ctx.Session!;
     }
 
     [CommandImplementation("imm")]
@@ -59,13 +59,13 @@ public sealed class PlayerCommand : ToolshedCommand
     }
 
     [CommandImplementation("entity")]
-    public IEnumerable<EntityUid> GetPlayerEntity([PipedArgument] IEnumerable<ICommonSession> sessions)
+    public IEnumerable<EntityUid> GetPlayerEntity([PipedArgument] IEnumerable<IPlayerSession> sessions)
     {
         return sessions.Select(x => x.AttachedEntity).Where(x => x is not null).Cast<EntityUid>();
     }
 
     [CommandImplementation("entity")]
-    public EntityUid GetPlayerEntity([PipedArgument] ICommonSession sessions)
+    public EntityUid GetPlayerEntity([PipedArgument] IPlayerSession sessions)
     {
         return sessions.AttachedEntity ?? default;
     }

Robust.Server/Upload/NetworkResourceManager.cs

@@ -5,7 +5,6 @@ using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.IoC;
 using Robust.Shared.Network;
-using Robust.Shared.Player;
 using Robust.Shared.Upload;
 using Robust.Shared.ViewVariables;
 
@@ -18,7 +17,7 @@ public sealed class NetworkResourceManager : SharedNetworkResourceManager
     [Dependency] private readonly IConfigurationManager _cfgManager = default!;
     [Dependency] private readonly IConGroupController _controller = default!;
 
-    public event Action<ICommonSession, NetworkResourceUploadMessage>? OnResourceUploaded;
+    public event Action<IPlayerSession, NetworkResourceUploadMessage>? OnResourceUploaded;
 
     [ViewVariables] public bool Enabled { get; private set; } = true;
     [ViewVariables] public float SizeLimit { get; private set; }

Robust.Server/ViewVariables/ServerViewVariablesManager.cs

@@ -6,13 +6,13 @@ using Robust.Server.Player;
 using Robust.Shared.Enums;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Log;
 using Robust.Shared.Network;
 using Robust.Shared.Network.Messages;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Serialization;
-using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Server.ViewVariables
@@ -31,8 +31,6 @@ namespace Robust.Server.ViewVariables
         private readonly Dictionary<uint, ViewVariablesSession>
             _sessions = new();
 
-        private readonly Dictionary<NetUserId, List<uint>> _users = new();
-
         private uint _nextSessionId = 1;
 
         public override void Initialize()
@@ -46,22 +44,6 @@ namespace Robust.Server.ViewVariables
             _netManager.RegisterNetMessage<MsgViewVariablesDenySession>();
             _netManager.RegisterNetMessage<MsgViewVariablesOpenSession>();
             _netManager.RegisterNetMessage<MsgViewVariablesRemoteData>();
-
-            _playerManager.PlayerStatusChanged += OnStatusChanged;
-        }
-
-        private void OnStatusChanged(object? sender, SessionStatusEventArgs e)
-        {
-            if (e.NewStatus != SessionStatus.Disconnected)
-                return;
-
-            if (!_users.TryGetValue(e.Session.UserId, out var vvSessions))
-                return;
-
-            foreach (var id in vvSessions)
-            {
-                _closeSession(id, false);
-            }
         }
 
         private void _msgCloseSession(MsgViewVariablesCloseSession message)
@@ -253,13 +235,19 @@ namespace Robust.Server.ViewVariables
                 _robustSerializer, _entityManager, Sawmill);
 
             _sessions.Add(sessionId, session);
-            _users.GetOrNew(session.PlayerUser).Add(sessionId);
 
             var allowMsg = new MsgViewVariablesOpenSession();
             allowMsg.RequestId = message.RequestId;
             allowMsg.SessionId = session.SessionId;
             _netManager.ServerSendMessage(allowMsg, message.MsgChannel);
 
+            player.PlayerStatusChanged += (_, args) =>
+            {
+                if (args.NewStatus == SessionStatus.Disconnected)
+                {
+                    _closeSession(session.SessionId, false);
+                }
+            };
         }
 
         private void _closeSession(uint sessionId, bool sendMsg)

Robust.Server/ViewVariables/ViewVariablesSession.cs

@@ -98,7 +98,7 @@ namespace Robust.Server.ViewVariables
             // Auto-dirty component. Only works when modifying a field that is directly on a component,
             // Does not work for nested objects.
             if (Object is Component comp)
-                EntityManager.Dirty(comp.Owner, comp);
+                EntityManager.Dirty(comp);
         }
 
         public bool TryGetRelativeObject(object[] propertyIndex, out object? value)

Robust.Shared.Scripting/ScriptGlobalsShared.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using System.Numerics;
 using System.Reflection;
 using System.Text;
@@ -9,7 +10,7 @@ using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Map;
 using Robust.Shared.Map.Components;
-using Robust.Shared.Player;
+using Robust.Shared.Players;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Toolshed;
 using Robust.Shared.Toolshed.Errors;
@@ -187,10 +188,10 @@ namespace Robust.Shared.Scripting
         }
 
         #region EntityManager proxy methods
-        public T Comp<T>(EntityUid uid) where T : IComponent
+        public T Comp<T>(EntityUid uid) where T : Component
             => ent.GetComponent<T>(uid);
 
-        public bool TryComp<T>(EntityUid uid, out T? comp) where T : IComponent
+        public bool TryComp<T>(EntityUid uid, out T? comp) where T : Component
             => ent.TryGetComponent(uid, out comp);
 
         public bool HasComp<T>(EntityUid uid)
@@ -206,7 +207,7 @@ namespace Robust.Shared.Scripting
             => ent.DirtyEntity(uid);
 
         public void Dirty(Component comp)
-            => ent.Dirty(comp.Owner, comp);
+            => ent.Dirty(comp);
 
         public string Name(EntityUid uid)
             => ent.GetComponent<MetaDataComponent>(uid).EntityName;

Robust.Shared/Analyzers/ComponentNetworkGeneratorAuxiliary.cs

@@ -10,7 +10,7 @@ namespace Robust.Shared.Analyzers;
 ///     component state replication beyond just directly setting variables should not use this attribute.
 /// </summary>
 [AttributeUsage(AttributeTargets.Class, Inherited = false)]
-[BaseTypeRequired(typeof(IComponent))]
+[BaseTypeRequired(typeof(Component))]
 public sealed class AutoGenerateComponentStateAttribute : Attribute
 {
     /// <summary>