Version: 162.2.2

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

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

@@ -54,6 +54,112 @@ END TEMPLATE-->
 *None yet*
 
 
+## 162.2.2
+
+
+## 162.2.1
+
+
+## 162.2.0
+
+### New features
+
+* Add support for automatically networking entity lists and sets.
+* Add nullable conversion operators for ProtoIds.
+* Add LocId serializer for validation.
+
+### Bugfixes
+
+* Fix deleting a contact inside of collision events throwing.
+* Localize VV.
+
+### Internal
+
+* Use CollectionsMarshal in GameStateManager.
+
+
+## 162.1.1
+
+### Bugfixes
+
+* Fixes "NoSpawn" entities appearing in the spawn menu.
+
+
+## 162.1.0
+
+### New features
+
+* Mark ProtoId as NetSerializable.
+
+### Bugfixes
+
+* Temporarily revert NetForceAckThreshold change as it can lead to client stalling.
+* Fix eye visibility layers not updating on children when a parent changes.
+
+### Internal
+
+* Use CollectionsMarshal in RobustTree and AddComponentInternal.
+
+
+## 162.0.0
+
+### New features
+
+* Add entity categories for prototypes and deprecate the `noSpawn` tag.
+* Add missing proxy method for `TryGetEntityData`.
+* Add NetForceAckThreshold cvar to forcibly update acks for late clients.
+
+### Internal
+
+* Use CollectionMarshals in PVS and DynamicTree.
+* Make the proxy methods use MetaQuery / TransformQuery.
+
+
+## 161.1.0
+
+### New features
+
+* Add more DebugTools assert variations.
+
+### Bugfixes
+
+* Don't attempt to insert entities into deleted containers.
+* Try to fix oldestAck not being set correctly leading to deletion history getting bloated for pvs.
+
+
+## 161.0.0
+
+### Breaking changes
+
+* Point light animations now need to use different component fields in order to animate the lights. `Enabled` should be replaced with `AnimatedEnable` and `Radius` should be replaced with `AnimatedRadius`
+
+### New features
+
+* EntProtoId is now net-serializable
+* Added print_pvs_ack command to debug PVS issues.
+
+### Bugfixes
+
+* Fixes AngleTypeParser not using InvariantCulture
+* Fixed a bug that was causing `MetaDataComponent.LastComponentRemoved` to be updated improperly.
+
+### Other
+
+* The string representation of client-side entities now looks nicer and simply uses a 'c' prefix.
+
+
+## 160.1.0
+
+### New features
+
+* Add optional MetaDataComponent args to Entitymanager methods.
+
+### Internal
+
+* Move _netComponents onto MetaDataComponent.
+* Remove some component resolves internally on adding / removing components.
+
+
 ## 160.0.2
 
 ### Other

Resources/EnginePrototypes/Debug/rotation.yml

@@ -1,7 +1,7 @@
 - type: entity
   id: debugRotation
   abstract: true
-  suffix: DEBUG
+  categories: [ debug ]
   components:
   - type: Sprite
     netsync: false

Resources/EnginePrototypes/entityCategory.yml

@@ -0,0 +1,17 @@
+# debug related entities
+- type: entityCategory
+  id: debug
+  name: entity-category-name-debug
+  description: entity-category-desc-debug
+
+# entities that spawn other entities
+- type: entityCategory
+  id: spawner
+  name: entity-category-name-spawner
+  description: entity-category-desc-spawner
+
+# entities that should be hidden from the spawn menu
+- type: entityCategory
+  id: hideSpawnMenu
+  name: entity-category-name-hide
+  description: entity-category-desc-hide

Resources/Locale/en-US/entity-category.ftl

@@ -0,0 +1,8 @@
+entity-category-name-debug = Debug
+entity-category-desc-debug = Entity prototypes intended for debugging & testing.
+
+entity-category-name-spawner = Spawner
+entity-category-desc-spawner = Entity prototypes that spawn other entities.
+
+entity-category-name-hide = Hidden
+entity-category-desc-hide = Entity prototypes that should be hidden from the spawn menu

Resources/Locale/en-US/view-variables.ftl

@@ -1,5 +1,6 @@
 ## ViewVariablesInstanceEntity
 
+view-variables = View Variables
 view-variable-instance-entity-server-components-add-component-button-placeholder = Add Component
 view-variable-instance-entity-client-variables-tab-title = Client Variables
 view-variable-instance-entity-client-components-tab-title = Client Components
@@ -8,4 +9,4 @@ view-variable-instance-entity-server-components-tab-title = Server Components
 view-variable-instance-entity-client-components-search-bar-placeholder = Search
 view-variable-instance-entity-server-components-search-bar-placeholder = Search
 view-variable-instance-entity-add-window-server-components = Add Component [S]
-view-variable-instance-entity-add-window-client-components = Add Component [C]
+view-variable-instance-entity-add-window-client-components = Add Component [C]

Robust.Client/GameStates/ClientDirtySystem.cs

@@ -1,7 +1,6 @@
 using Robust.Client.Timing;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
-using Robust.Shared.Log;
 using Robust.Shared.Utility;
 using System;
 using System.Collections.Generic;
@@ -54,7 +53,7 @@ public sealed class ClientDirtySystem : EntitySystem
 
         var uid = args.BaseArgs.Owner;
         var comp = args.BaseArgs.Component;
-        if (!_timing.InPrediction || !comp.NetSyncEnabled || IsClientSide(uid))
+        if (!_timing.InPrediction || !comp.NetSyncEnabled || IsClientSide(uid, args.Meta))
             return;
 
         // Was this component added during prediction? If yes, then there is no need to re-add it when resetting.

Robust.Client/GameStates/ClientGameStateManager.cs

@@ -4,6 +4,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Runtime.InteropServices;
 using JetBrains.Annotations;
 using Robust.Client.GameObjects;
 using Robust.Client.Input;
@@ -47,7 +48,7 @@ namespace Robust.Client.GameStates
                 = new();
 
         // Game state dictionaries that get used every tick.
-        private readonly Dictionary<EntityUid, (NetEntity NetEntity, bool EnteringPvs, GameTick LastApplied, EntityState? curState, EntityState? nextState)> _toApply = new();
+        private readonly Dictionary<EntityUid, (NetEntity NetEntity, MetaDataComponent Meta, bool EnteringPvs, GameTick LastApplied, EntityState? curState, EntityState? nextState)> _toApply = new();
         private readonly Dictionary<NetEntity, EntityState> _toCreate = new();
         private readonly Dictionary<ushort, (IComponent Component, ComponentState? curState, ComponentState? nextState)> _compStateWork = new();
         private readonly Dictionary<EntityUid, HashSet<Type>> _pendingReapplyNetStates = new();
@@ -497,11 +498,7 @@ namespace Robust.Client.GameStates
 
                 countReset += 1;
 
-                var netComps = _entityManager.GetNetComponentsOrNull(entity);
-                if (netComps == null)
-                    continue;
-
-                foreach (var (netId, comp) in netComps.Value)
+                foreach (var (netId, comp) in meta.NetComponents)
                 {
                     if (!comp.NetSyncEnabled)
                         continue;
@@ -549,13 +546,13 @@ namespace Robust.Client.GameStates
                 {
                     foreach (var netId in netIds)
                     {
-                        if (_entities.HasComponent(entity, netId))
+                        if (meta.NetComponents.ContainsKey(netId))
                             continue;
 
                         if (!last.TryGetValue(netId, out var state))
                             continue;
 
-                        var comp = _entityManager.AddComponent(entity, netId);
+                        var comp = _entityManager.AddComponent(entity, netId, meta);
 
                         if (_sawmill.Level <= LogLevel.Debug)
                             _sawmill.Debug($"  A component was removed: {comp.GetType()}");
@@ -597,11 +594,11 @@ namespace Robust.Client.GameStates
 
             foreach (var netEntity in createdEntities)
             {
-                var createdEntity = _entityManager.GetEntity(netEntity);
+                var (createdEntity, meta) = _entityManager.GetEntityData(netEntity);
                 var compData = new Dictionary<ushort, ComponentState>();
                 outputData.Add(netEntity, compData);
 
-                foreach (var (netId, component) in _entityManager.GetNetComponents(createdEntity))
+                foreach (var (netId, component) in meta.NetComponents)
                 {
                     if (!component.NetSyncEnabled)
                         continue;
@@ -692,9 +689,9 @@ namespace Robust.Client.GameStates
 
                     var uid = _entities.CreateEntity(metaState.PrototypeId);
                     _toCreate.Add(es.NetEntity, es);
-                    _toApply.Add(uid, (es.NetEntity, false, GameTick.Zero, es, null));
-
                     var newMeta = metas.GetComponent(uid);
+                    _toApply.Add(uid, (es.NetEntity, newMeta, false, GameTick.Zero, es, null));
+
 
                     // Client creates a client-side net entity for the newly created entity.
                     // We need to clear this mapping before assigning the real net id.
@@ -742,7 +739,7 @@ namespace Robust.Client.GameStates
                     continue;
                 }
 
-                _toApply.Add(uid, (es.NetEntity, isEnteringPvs, meta.LastStateApplied, es, null));
+                _toApply.Add(uid, (es.NetEntity, meta, isEnteringPvs, meta.LastStateApplied, es, null));
                 meta.LastStateApplied = curState.ToSequence;
             }
 
@@ -756,34 +753,36 @@ namespace Robust.Client.GameStates
             {
                 foreach (var es in nextState.EntityStates.Span)
                 {
-                    if (!_entityManager.TryGetEntity(es.NetEntity, out var uid))
+                    if (!_entityManager.TryGetEntityData(es.NetEntity, out var uid, out var meta))
                         continue;
 
-                    DebugTools.Assert(metas.HasComponent(uid));
-
                     // Does the next state actually have any future information about this entity that could be used for interpolation?
                     if (es.EntityLastModified != nextState.ToSequence)
                         continue;
 
-                    if (_toApply.TryGetValue(uid.Value, out var state))
-                        _toApply[uid.Value] = (es.NetEntity, state.EnteringPvs, state.LastApplied, state.curState, es);
+                    ref var state = ref CollectionsMarshal.GetValueRefOrAddDefault(_toApply, uid.Value, out var exists);
+
+                    if (exists)
+                        state = (es.NetEntity, meta, state.EnteringPvs, state.LastApplied, state.curState, es);
                     else
-                        _toApply[uid.Value] = (es.NetEntity, false, GameTick.Zero, null, es);
+                        state = (es.NetEntity, meta, false, GameTick.Zero, null, es);
                 }
             }
 
             // Check pending states and see if we need to force any entities to re-run component states.
             foreach (var uid in _pendingReapplyNetStates.Keys)
             {
-                // State already being re-applied so don't bulldoze it.
-                if (_toApply.ContainsKey(uid))
-                    continue;
-
                 // Original entity referencing the NetEntity may have been deleted.
                 if (!metas.TryGetComponent(uid, out var meta))
                     continue;
 
-                _toApply[uid] = (_entityManager.GetNetEntity(uid, meta), false, GameTick.Zero, null, null);
+                // State already being re-applied so don't bulldoze it.
+                ref var state = ref CollectionsMarshal.GetValueRefOrAddDefault(_toApply, uid, out var exists);
+
+                if (exists)
+                    continue;
+
+                state = (meta.NetEntity, meta, false, GameTick.Zero, null, null);
             }
 
             var queuedBroadphaseUpdates = new List<(EntityUid, TransformComponent)>(enteringPvs);
@@ -793,7 +792,7 @@ namespace Robust.Client.GameStates
             {
                 foreach (var (entity, data) in _toApply)
                 {
-                    HandleEntityState(entity, data.NetEntity, _entities.EventBus, data.curState,
+                    HandleEntityState(entity, data.NetEntity, data.Meta, _entities.EventBus, data.curState,
                         data.nextState, data.LastApplied, curState.ToSequence, data.EnteringPvs);
 
                     if (!data.EnteringPvs)
@@ -1133,7 +1132,7 @@ namespace Robust.Client.GameStates
 #endif
         }
 
-        private void HandleEntityState(EntityUid uid, NetEntity netEntity, IEventBus bus, EntityState? curState,
+        private void HandleEntityState(EntityUid uid, NetEntity netEntity, MetaDataComponent meta, IEventBus bus, EntityState? curState,
             EntityState? nextState, GameTick lastApplied, GameTick toTick, bool enteringPvs)
         {
             _compStateWork.Clear();
@@ -1142,7 +1141,7 @@ namespace Robust.Client.GameStates
             if (curState?.NetComponents != null)
             {
                 RemQueue<Component> toRemove = new();
-                foreach (var (id, comp) in _entities.GetNetComponents(uid))
+                foreach (var (id, comp) in meta.NetComponents)
                 {
                     if (comp.NetSyncEnabled && !curState.NetComponents.Contains(id))
                         toRemove.Add(comp);
@@ -1150,7 +1149,7 @@ namespace Robust.Client.GameStates
 
                 foreach (var comp in toRemove)
                 {
-                    _entities.RemoveComponent(uid, comp);
+                    _entities.RemoveComponent(uid, comp, meta);
                 }
             }
 
@@ -1163,12 +1162,11 @@ namespace Robust.Client.GameStates
                 // the entity. most notably, all entities will have been ejected from their containers.
                 foreach (var (id, state) in _processor.GetLastServerStates(netEntity))
                 {
-                    if (!_entityManager.TryGetComponent(uid, id, out var comp))
+                    if (!meta.NetComponents.TryGetValue(id, out var comp))
                     {
-                        comp = _compFactory.GetComponent(id);
-                        var newComp = (Component)comp;
-                        newComp.Owner = uid;
-                        _entityManager.AddComponent(uid, newComp, true);
+                        comp = (Component) _compFactory.GetComponent(id);
+                        comp.Owner = uid;
+                        _entityManager.AddComponent(uid, comp, true, metadata: meta);
                     }
 
                     _compStateWork[id] = (comp, state, null);
@@ -1178,12 +1176,11 @@ namespace Robust.Client.GameStates
             {
                 foreach (var compChange in curState.ComponentChanges.Span)
                 {
-                    if (!_entityManager.TryGetComponent(uid, compChange.NetID, out var comp))
+                    if (!meta.NetComponents.TryGetValue(compChange.NetID, out var comp))
                     {
-                        comp = _compFactory.GetComponent(compChange.NetID);
-                        var newComp = (Component)comp;
-                        newComp.Owner = uid;
-                        _entityManager.AddComponent(uid, newComp, true);
+                        comp = (Component) _compFactory.GetComponent(compChange.NetID);
+                        comp.Owner = uid;
+                        _entityManager.AddComponent(uid, comp, true, metadata:meta);
                     }
                     else if (compChange.LastModifiedTick <= lastApplied && lastApplied != GameTick.Zero)
                         continue;
@@ -1199,17 +1196,20 @@ namespace Robust.Client.GameStates
                     if (compState.LastModifiedTick != toTick + 1)
                         continue;
 
-                    if (!_entityManager.TryGetComponent(uid, compState.NetID, out var comp))
+                    if (!meta.NetComponents.TryGetValue(compState.NetID, out var comp))
                     {
                         // The component can be null here due to interp, because the NEXT state will have a new
                         // component, but the component does not yet exist.
                         continue;
                     }
 
-                    if (_compStateWork.TryGetValue(compState.NetID, out var state))
-                        _compStateWork[compState.NetID] = (comp, state.curState, compState.State);
+                    ref var state =
+                        ref CollectionsMarshal.GetValueRefOrAddDefault(_compStateWork, compState.NetID, out var exists);
+
+                    if (exists)
+                        state = (comp, state.curState, compState.State);
                     else
-                        _compStateWork[compState.NetID] = (comp, null, compState.State);
+                        state = (comp, null, compState.State);
                 }
             }
 
@@ -1226,14 +1226,19 @@ namespace Robust.Client.GameStates
                     if (netId == null)
                         continue;
 
-                    if (_compStateWork.ContainsKey(netId.Value) ||
-                        !_entityManager.TryGetComponent(uid, type, out var comp) ||
+                    if (!meta.NetComponents.TryGetValue(netId.Value, out var comp) ||
                         !lastState.TryGetValue(netId.Value, out var lastCompState))
                     {
                         continue;
                     }
 
-                    _compStateWork[netId.Value] = (comp, lastCompState, null);
+                    ref var compState =
+                        ref CollectionsMarshal.GetValueRefOrAddDefault(_compStateWork, netId.Value, out var exists);
+
+                    if (exists)
+                        continue;
+
+                    compState = (comp, lastCompState, null);
                 }
             }
 
@@ -1247,10 +1252,10 @@ namespace Robust.Client.GameStates
                 catch (Exception e)
                 {
 #if EXCEPTION_TOLERANCE
-                        _sawmill.Error($"Failed to apply comp state: entity={comp.Owner}, comp={comp.GetType()}");
-                        _runtimeLog.LogException(e, $"{nameof(ClientGameStateManager)}.{nameof(HandleEntityState)}");
+                    _sawmill.Error($"Failed to apply comp state: entity={_entities.ToPrettyString(uid)}, comp={comp.GetType()}");
+                    _runtimeLog.LogException(e, $"{nameof(ClientGameStateManager)}.{nameof(HandleEntityState)}");
 #else
-                    _sawmill.Error($"Failed to apply comp state: entity={uid}, comp={comp.GetType()}");
+                    _sawmill.Error($"Failed to apply comp state: entity={_entities.ToPrettyString(uid)}, comp={comp.GetType()}");
                     throw;
 #endif
                 }
@@ -1398,12 +1403,11 @@ namespace Robust.Client.GameStates
 
             foreach (var (id, state) in lastState)
             {
-                if (!_entityManager.TryGetComponent(uid, id, out var comp))
+                if (!meta.NetComponents.TryGetValue(id, out var comp))
                 {
-                    comp = _compFactory.GetComponent(id);
-                    var newComp = (Component)comp;
-                    newComp.Owner = uid;
-                    _entityManager.AddComponent(uid, newComp, true);
+                    comp = (Component) _compFactory.GetComponent(id);
+                    comp.Owner = uid;
+                    _entityManager.AddComponent(uid, comp, true, meta);
                 }
 
                 var handleState = new ComponentHandleState(state, null);
@@ -1412,7 +1416,7 @@ namespace Robust.Client.GameStates
 
             // ensure we don't have any extra components
             RemQueue<Component> toRemove = new();
-            foreach (var (id, comp) in _entities.GetNetComponents(uid))
+            foreach (var (id, comp) in meta.NetComponents)
             {
                 if (comp.NetSyncEnabled && !lastState.ContainsKey(id))
                     toRemove.Add(comp);

Robust.Client/GameStates/GameStateProcessor.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.InteropServices;
 using Robust.Client.Timing;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
@@ -361,9 +362,11 @@ namespace Robust.Client.GameStates
 
                 foreach (var (netId, implicitCompState) in implicitEntState)
                 {
-                    if (!fullRep.TryGetValue(netId, out var serverState))
+                    ref var serverState = ref CollectionsMarshal.GetValueRefOrAddDefault(fullRep, netId, out var exists);
+
+                    if (!exists)
                     {
-                        fullRep.Add(netId, implicitCompState);
+                        serverState = implicitCompState;
                         continue;
                     }
 
@@ -379,7 +382,7 @@ namespace Robust.Client.GameStates
                     }
 
                     serverDelta.ApplyToFullState(implicitCompState);
-                    fullRep[netId] = implicitCompState;
+                    serverState = implicitCompState;
                     DebugTools.Assert(implicitCompState is IComponentDeltaState d && d.FullState);
                 }
             }

Robust.Client/Graphics/IClydeWindow.cs

@@ -38,8 +38,7 @@ namespace Robust.Client.Graphics
         event Action<WindowDestroyedEventArgs> Destroyed;
 
         /// <summary>
-        /// Raised when the window has been definitively closed.
-        /// This means the window must not be used anymore (it is disposed).
+        /// Raised when the window has been resized.
         /// </summary>
         event Action<WindowResizedEventArgs> Resized;
     }

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/Controllers/Implementations/EntitySpawningUIController.cs

@@ -10,6 +10,7 @@ using Robust.Client.UserInterface.CustomControls;
 using Robust.Shared.Enums;
 using Robust.Shared.IoC;
 using Robust.Shared.Prototypes;
+using Robust.Shared.Serialization.Manager.Attributes;
 using Robust.Shared.Utility;
 using static Robust.Client.UserInterface.Controls.BaseButton;
 using static Robust.Client.UserInterface.Controls.LineEdit;
@@ -199,7 +200,7 @@ public sealed class EntitySpawningUIController : UIController
                 continue;
             }
 
-            if (prototype.NoSpawn)
+            if (prototype.HideSpawnMenu)
             {
                 continue;
             }

Robust.Client/UserInterface/Controls/LineEdit.cs

@@ -98,6 +98,11 @@ namespace Robust.Client.UserInterface.Controls
                 OnTextChanged?.Invoke(new LineEditEventArgs(this, _text));
         }
 
+        public void ForceSubmitText()
+        {
+            OnTextEntered?.Invoke(new LineEditEventArgs(this, _text));
+        }
+
         /// <summary>
         ///     The text
         /// </summary>
@@ -607,7 +612,7 @@ namespace Robust.Client.UserInterface.Controls
                 {
                     if (Editable)
                     {
-                        OnTextEntered?.Invoke(new LineEditEventArgs(this, _text));
+                        ForceSubmitText();
                     }
 
                     args.Handle();

Robust.Client/UserInterface/Controls/ScrollContainer.cs

@@ -50,13 +50,13 @@ namespace Robust.Client.UserInterface.Controls
             Action<Range> ev = _scrollValueChanged;
             _hScrollBar = new HScrollBar
             {
-                Visible = false,
+                Visible = _hScrollEnabled,
                 VerticalAlignment = VAlignment.Bottom,
                 HorizontalAlignment = HAlignment.Stretch
             };
             _vScrollBar = new VScrollBar
             {
-                Visible = false,
+                Visible = _vScrollEnabled,
                 VerticalAlignment = VAlignment.Stretch,
                 HorizontalAlignment = HAlignment.Right
             };

Robust.Client/ViewVariables/ClientViewVariablesManager.cs

@@ -10,6 +10,7 @@ using Robust.Client.ViewVariables.Editors;
 using Robust.Client.ViewVariables.Instances;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
+using Robust.Shared.Localization;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Network;
@@ -232,7 +233,7 @@ namespace Robust.Client.ViewVariables
                 instance = new ViewVariablesInstanceObject(this, _robustSerializer);
             }
 
-            var window = new DefaultWindow {Title = "View Variables"};
+            var window = new DefaultWindow {Title = Loc.GetString("view-variables")};
             instance.Initialize(window, obj);
             window.OnClose += () => _closeInstance(instance, false);
             _windows.Add(instance, window);
@@ -250,7 +251,7 @@ namespace Robust.Client.ViewVariables
         {
             var window = new DefaultWindow
             {
-                Title = "View Variables",
+                Title = Loc.GetString("view-variables"),
                 SetSize = _defaultWindowSize
             };
             var loadingLabel = new Label {Text = "Retrieving remote object data from server..."};

Robust.Server/GameObjects/EntitySystems/MapLoaderSystem.cs

@@ -879,7 +879,7 @@ public sealed class MapLoaderSystem : EntitySystem
             return;
         }
 
-        foreach (var (netId, component) in EntityManager.GetNetComponents(entity))
+        foreach (var component in metadata.NetComponents.Values)
         {
             var compName = _factory.GetComponentName(component.GetType());
 

Robust.Server/GameObjects/EntitySystems/ServerMetaDataSystem.cs

@@ -7,6 +7,7 @@ namespace Robust.Server.GameObjects;
 public sealed class ServerMetaDataSystem : MetaDataSystem
 {
     [Dependency] private readonly PvsSystem _pvsSystem = default!;
+    private EntityQuery<MetaDataComponent> _mQuery;
 
     public override void Initialize()
     {
@@ -16,6 +17,7 @@ public sealed class ServerMetaDataSystem : MetaDataSystem
 
         EntityManager.ComponentAdded += OnComponentAdded;
         EntityManager.ComponentRemoved += OnComponentRemoved;
+        _mQuery = GetEntityQuery<MetaDataComponent>();
     }
 
     public override void Shutdown()
@@ -45,7 +47,7 @@ public sealed class ServerMetaDataSystem : MetaDataSystem
         if (obj.Terminating || !removed.NetSyncEnabled || (!removed.SessionSpecific && !removed.SendOnlyToOwner))
             return;
 
-        foreach (var (_, comp) in EntityManager.GetNetComponents(obj.BaseArgs.Owner))
+        foreach (var comp in obj.Meta.NetComponents.Values)
         {
             if (comp.LifeStage >= ComponentLifeStage.Removing)
                 continue;
@@ -55,7 +57,7 @@ public sealed class ServerMetaDataSystem : MetaDataSystem
         }
 
         // remove the flag
-        MetaData(obj.BaseArgs.Owner).Flags &= ~MetaDataFlags.SessionSpecific;
+        obj.Meta.Flags &= ~MetaDataFlags.SessionSpecific;
     }
 
     /// <summary>
@@ -67,19 +69,10 @@ public sealed class ServerMetaDataSystem : MetaDataSystem
         if ((meta.Flags & MetaDataFlags.SessionSpecific) == 0)
             return;
 
-        foreach (var (_, comp) in EntityManager.GetNetComponents(uid))
+        foreach (var (_, comp) in meta.NetComponents)
         {
             if (comp.SessionSpecific || comp.SendOnlyToOwner)
                 Dirty(uid, comp);
         }
     }
-
-    public override void SetVisibilityMask(EntityUid uid, int value, MetaDataComponent? meta = null)
-    {
-        if (!Resolve(uid, ref meta) || meta.VisibilityMask == value)
-            return;
-
-        base.SetVisibilityMask(uid, value, meta);
-        _pvsSystem.MarkDirty(uid);
-    }
 }

Robust.Server/GameObjects/EntitySystems/VisibilitySystem.cs

@@ -1,4 +1,5 @@
 using System;
+using Robust.Server.GameStates;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 
@@ -6,11 +7,18 @@ namespace Robust.Server.GameObjects
 {
     public sealed class VisibilitySystem : EntitySystem
     {
-        [Dependency] private readonly MetaDataSystem _metaSys = default!;
+        [Dependency] private readonly PvsSystem _pvs = default!;
+
+        private EntityQuery<TransformComponent> _xformQuery;
+        private EntityQuery<MetaDataComponent> _metaQuery;
+        private EntityQuery<VisibilityComponent> _visiblityQuery;
 
         public override void Initialize()
         {
             base.Initialize();
+            _xformQuery = GetEntityQuery<TransformComponent>();
+            _metaQuery = GetEntityQuery<MetaDataComponent>();
+            _visiblityQuery = GetEntityQuery<VisibilityComponent>();
             SubscribeLocalEvent<EntParentChangedMessage>(OnParentChange);
             EntityManager.EntityInitialized += OnEntityInit;
         }
@@ -82,27 +90,58 @@ namespace Robust.Server.GameObjects
             RefreshVisibility(uid);
         }
 
-        public void RefreshVisibility(EntityUid uid, MetaDataComponent? metaDataComponent = null, VisibilityComponent? visibilityComponent = null)
+        public void RefreshVisibility(EntityUid uid,
+            VisibilityComponent? visibilityComponent = null,
+            MetaDataComponent? meta = null)
         {
-            if (Resolve(uid, ref metaDataComponent, false))
-                _metaSys.SetVisibilityMask(uid, GetVisibilityMask(uid, visibilityComponent), metaDataComponent);
+            if (!_metaQuery.Resolve(uid, ref meta, false))
+                return;
+
+            // Iterate up through parents and calculate the cumulative visibility mask.
+            var mask = GetParentVisibilityMask(uid, visibilityComponent);
+
+            // Iterate down through children and propagate mask changes.
+            RecursivelyApplyVisibility(uid, mask, meta);
+        }
+
+        private void RecursivelyApplyVisibility(EntityUid uid, int mask, MetaDataComponent meta)
+        {
+            if (meta.VisibilityMask == mask)
+                return;
+
+            var xform = _xformQuery.GetComponent(uid);
+            meta.VisibilityMask = mask;
+            _pvs.MarkDirty(uid, xform);
+
+            foreach (var child in xform.ChildEntities)
+            {
+                if (!_metaQuery.TryGetComponent(child, out var childMeta))
+                    continue;
+
+                var childMask = mask;
+
+                if (_visiblityQuery.TryGetComponent(child, out VisibilityComponent? hildVis))
+                    childMask |= hildVis.Layer;
+
+                RecursivelyApplyVisibility(child, childMask, childMeta);
+            }
         }
 
         [Obsolete("Use overload that takes an EntityUid instead")]
         public void RefreshVisibility(VisibilityComponent visibilityComponent)
         {
-            RefreshVisibility(visibilityComponent.Owner, null, visibilityComponent);
+            RefreshVisibility(visibilityComponent.Owner, visibilityComponent);
         }
 
-        private int GetVisibilityMask(EntityUid uid, VisibilityComponent? visibilityComponent = null, TransformComponent? xform = null)
+        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.
-            if (Resolve(uid, ref visibilityComponent, false))
+            if (_visiblityQuery.Resolve(uid, ref visibilityComponent, false))
                 visMask |= visibilityComponent.Layer;
 
             // Include parent vis masks
-            if (Resolve(uid, ref xform) && xform.ParentUid.IsValid())
-                visMask |= GetVisibilityMask(xform.ParentUid);
+            if (_xformQuery.TryGetComponent(uid, out var xform) && xform.ParentUid.IsValid())
+                visMask |= GetParentVisibilityMask(xform.ParentUid);
 
             return visMask;
         }

Robust.Server/GameObjects/ServerEntityManager.cs

@@ -139,9 +139,6 @@ namespace Robust.Server.GameObjects
         {
             _networkManager.RegisterNetMessage<MsgEntity>(HandleEntityNetworkMessage);
 
-            // For syncing component deletions.
-            ComponentRemoved += OnComponentRemoved;
-
             _playerManager.PlayerStatusChanged += OnPlayerStatusChanged;
 
             _configurationManager.OnValueChanged(CVars.NetLogLateMsg, b => _logLateMsgs = b, true);
@@ -168,15 +165,6 @@ namespace Robust.Server.GameObjects
             return _lastProcessedSequencesCmd[session];
         }
 
-        private void OnComponentRemoved(RemovedComponentEventArgs e)
-        {
-            if (e.Terminating || !e.BaseArgs.Component.NetSyncEnabled)
-                return;
-
-            if (TryGetComponent(e.BaseArgs.Owner, out MetaDataComponent? meta))
-                meta.LastComponentRemoved = _gameTiming.CurTick;
-        }
-
         /// <inheritdoc />
         public void SendSystemNetworkMessage(EntityEventArgs message, bool recordReplay = true)
         {

Robust.Server/GameStates/PvsSystem.Dirty.cs

@@ -92,9 +92,9 @@ namespace Robust.Server.GameStates
         /// <summary>
         ///     Marks an entity's current chunk as dirty.
         /// </summary>
-        internal void MarkDirty(EntityUid uid)
+        internal void MarkDirty(EntityUid uid, TransformComponent xform)
         {
-            var coordinates = _transform.GetMoverCoordinates(uid);
+            var coordinates = _transform.GetMoverCoordinates(uid, xform);
             _entityPvsCollection.MarkDirty(_entityPvsCollection.GetChunkIndex(coordinates));
         }
     }

Robust.Server/GameStates/PvsSystem.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;
+using System.Runtime.InteropServices;
 using System.Text;
 using Microsoft.Extensions.ObjectPool;
 using Robust.Server.Configuration;
@@ -24,7 +25,7 @@ namespace Robust.Server.GameStates;
 internal sealed partial class PvsSystem : EntitySystem
 {
     [Shared.IoC.Dependency] private readonly IConfigurationManager _configManager = default!;
-    [Shared.IoC.Dependency] private readonly IMapManagerInternal _mapManager = default!;
+    [Shared.IoC.Dependency] private readonly INetworkedMapManager _mapManager = default!;
     [Shared.IoC.Dependency] private readonly IPlayerManager _playerManager = default!;
     [Shared.IoC.Dependency] private readonly IParallelManager _parallelManager = default!;
     [Shared.IoC.Dependency] private readonly IServerGameStateManager _serverGameStateManager = default!;
@@ -227,6 +228,7 @@ internal sealed partial class PvsSystem : EntitySystem
     public void CullDeletionHistory(GameTick oldestAck)
     {
         _entityPvsCollection.CullDeletionHistoryUntil(oldestAck);
+        _mapManager.CullDeletionHistory(oldestAck);
     }
 
     #region PVSCollection methods to maybe make public someday:tm:
@@ -313,7 +315,7 @@ internal sealed partial class PvsSystem : EntitySystem
         // since elements are cached grid-/map-relative, we don't need to update a given grids/maps children
         DebugTools.Assert(!_mapManager.IsGrid(uid) && !_mapManager.IsMap(uid));
 
-        var indices = PVSCollection<EntityUid>.GetChunkIndices(coordinates.Position);
+        var indices = PVSCollection<NetEntity>.GetChunkIndices(coordinates.Position);
         if (xform.GridUid != null)
             _entityPvsCollection.UpdateIndex(metadata.NetEntity, xform.GridUid.Value, indices, forceDirty: forceDirty);
         else
@@ -648,16 +650,16 @@ internal sealed partial class PvsSystem : EntitySystem
         }
     }
 
-    private bool AddToChunkSetRecursively(in EntityUid uid, in NetEntity netEntity, MetaDataComponent mComp,
+    private void AddToChunkSetRecursively(in EntityUid uid, in NetEntity netEntity, MetaDataComponent mComp,
         int visMask, RobustTree<NetEntity> tree, Dictionary<NetEntity, MetaDataComponent> set)
     {
-        if (set.ContainsKey(netEntity))
-            return true;
-
-        // TODO: Don't need to know about parents so no longer need to use bool for this method.
-        // If the eye is missing ANY layer this entity or any of its parents belongs to, it is considered invisible.
+        // If the eye is missing ANY layer that this entity is on, or any layer that any of its parents belongs to, then
+        // it is considered invisible.
         if ((visMask & mComp.VisibilityMask) != mComp.VisibilityMask)
-            return false;
+            return;
+
+        if (!set.TryAdd(netEntity, mComp))
+            return; // already sending
 
         var xform = _xformQuery.GetComponent(uid);
 
@@ -667,8 +669,7 @@ internal sealed partial class PvsSystem : EntitySystem
         {
             DebugTools.Assert(_mapManager.IsGrid(uid) || _mapManager.IsMap(uid));
             tree.Set(netEntity);
-            set.Add(netEntity, mComp);
-            return true;
+            return;
         }
 
         DebugTools.Assert(!_mapManager.IsGrid(uid) && !_mapManager.IsMap(uid));
@@ -677,15 +678,12 @@ internal sealed partial class PvsSystem : EntitySystem
         var parentMeta = _metaQuery.GetComponent(parent);
         var parentNetEntity = parentMeta.NetEntity;
 
-        if (!AddToChunkSetRecursively(in parent, in parentNetEntity, parentMeta, visMask, tree, set)) //did we just fail to add the parent?
-        {
-            return false; //we failed? suppose we dont get added either
-        }
+        // Child should have all o the same flags as the parent.
+        DebugTools.Assert((parentMeta.VisibilityMask & mComp.VisibilityMask) == parentMeta.VisibilityMask);
 
-        //i want it to crash here if it gets added double bc that shouldnt happen and will add alot of unneeded cycles
+        // Add our parent.
+        AddToChunkSetRecursively(in parent, in parentNetEntity, parentMeta, visMask, tree, set);
         tree.Set(netEntity, parentNetEntity);
-        set.Add(netEntity, mComp);
-        return true;
     }
 
     internal (List<EntityState>? updates, List<NetEntity>? deletions, List<NetEntity>? leftPvs, GameTick fromTick)
@@ -900,15 +898,22 @@ internal sealed partial class PvsSystem : EntitySystem
             // As every map is parented to uid 0 in the tree we still need to get their children, plus because we go top-down
             // we may find duplicate parents with children we haven't encountered before
             // on different chunks (this is especially common with direct grid children)
-            if (!toSend.ContainsKey(currentNodeIndex))
+
+            ref var value = ref CollectionsMarshal.GetValueRefOrAddDefault(toSend, currentNodeIndex, out var exists);
+            if (!exists)
             {
                 var (entered, shouldAdd) = ProcessEntry(in currentNodeIndex, lastAcked, lastSent, lastSeen,
                     ref newEntityCount, ref enteredEntityCount, newEntityBudget, enteredEntityBudget);
 
                 if (!shouldAdd)
+                {
+                    // In the majority of instances entities do get added.
+                    // So its better to add and maybe remove, rather than checking ContainsKey() and then maybe adding it.
+                    toSend.Remove(currentNodeIndex);
                     continue;
+                }
 
-                AddToSendSet(in currentNodeIndex, metaDataCache[currentNodeIndex], toSend, fromTick, in entered, ref entStateCount);
+                AddToSendSet(in currentNodeIndex, metaDataCache[currentNodeIndex], ref value, toSend, fromTick, in entered, ref entStateCount);
             }
 
             var node = tree[currentNodeIndex];
@@ -957,14 +962,15 @@ internal sealed partial class PvsSystem : EntitySystem
         // to the toSend set, it doesn't guarantee that its parents have been. E.g., if a player ghost just teleported
         // to follow a far away entity, the player's own entity is still being sent, but we need to ensure that we also
         // send the new parents, which may otherwise be delayed because of the PVS budget..
-        if (!toSend.ContainsKey(netEntity))
+        ref var value = ref CollectionsMarshal.GetValueRefOrAddDefault(toSend, netEntity, out var exists);
+        if (!exists)
         {
             // TODO PERFORMANCE.
             // ProcessEntry() unnecessarily checks lastSent.ContainsKey() and maybe lastSeen.Contains(). Given that at this
             // point the budgets are just ignored, this should just bypass those checks. But then again 99% of the time this
             // is just the player's own entity + maybe a singularity. So currently not all that performance intensive.
             var (entered, _) = ProcessEntry(in netEntity, lastAcked, lastSent, lastSeen, ref newEntityCount, ref enteredEntityCount, newEntityBudget, enteredEntityBudget);
-            AddToSendSet(in netEntity, metadata, toSend, fromTick, in entered, ref entStateCount);
+            AddToSendSet(in netEntity, metadata, ref value, toSend, fromTick, in entered, ref entStateCount);
         }
 
         if (addChildren)
@@ -996,12 +1002,13 @@ internal sealed partial class PvsSystem : EntitySystem
             var metadata = _metaQuery.GetComponent(child);
             var childNetEntity = metadata.NetEntity;
 
-            if (!toSend.ContainsKey(childNetEntity))
+            ref var value = ref CollectionsMarshal.GetValueRefOrAddDefault(toSend, childNetEntity, out var exists);
+            if (!exists)
             {
                 var (entered, _) = ProcessEntry(in childNetEntity, lastAcked, lastSent, lastSeen, ref newEntityCount,
                     ref enteredEntityCount, newEntityBudget, enteredEntityBudget);
 
-                AddToSendSet(in childNetEntity, metadata, toSend, fromTick, in entered, ref entStateCount);
+                AddToSendSet(in childNetEntity, metadata, ref value, toSend, fromTick, in entered, ref entStateCount);
             }
 
             RecursivelyAddChildren(childXform, lastAcked, lastSent, toSend, lastSeen, fromTick, ref newEntityCount,
@@ -1044,10 +1051,13 @@ internal sealed partial class PvsSystem : EntitySystem
         return (entered, true);
     }
 
-    private void AddToSendSet(in NetEntity netEntity, MetaDataComponent metaDataComponent, Dictionary<NetEntity, PvsEntityVisibility> toSend, GameTick fromTick, in bool entered, ref int entStateCount)
+    private void AddToSendSet(in NetEntity netEntity, MetaDataComponent metaDataComponent,
+        ref PvsEntityVisibility vis, Dictionary<NetEntity, PvsEntityVisibility> toSend,
+        GameTick fromTick, in bool entered, ref int entStateCount)
     {
         if (metaDataComponent.EntityLifeStage >= EntityLifeStage.Terminating)
         {
+            toSend.Remove(netEntity);
             var rep = new EntityStringRepresentation(GetEntity(netEntity), metaDataComponent.EntityDeleted, metaDataComponent.EntityName, metaDataComponent.EntityPrototype?.ID);
             Log.Error($"Attempted to add a deleted entity to PVS send set: '{rep}'. Trace:\n{Environment.StackTrace}");
             return;
@@ -1055,7 +1065,7 @@ internal sealed partial class PvsSystem : EntitySystem
 
         if (entered)
         {
-            toSend.Add(netEntity, PvsEntityVisibility.Entered);
+            vis = PvsEntityVisibility.Entered;
             entStateCount++;
             return;
         }
@@ -1063,12 +1073,12 @@ internal sealed partial class PvsSystem : EntitySystem
         if (metaDataComponent.EntityLastModifiedTick <= fromTick)
         {
             //entity has been sent before and hasnt been updated since
-            toSend.Add(netEntity, PvsEntityVisibility.StayedUnchanged);
+            vis = PvsEntityVisibility.StayedUnchanged;
             return;
         }
 
         //add us
-        toSend.Add(netEntity, PvsEntityVisibility.StayedChanged);
+        vis = PvsEntityVisibility.StayedChanged;
         entStateCount++;
     }
 
@@ -1204,7 +1214,7 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
         bool sendCompList = meta.LastComponentRemoved > fromTick;
         HashSet<ushort>? netComps = sendCompList ? new() : null;
 
-        foreach (var (netId, component) in EntityManager.GetNetComponents(entityUid))
+        foreach (var (netId, component) in meta.NetComponents)
         {
             if (!component.NetSyncEnabled)
                 continue;
@@ -1253,7 +1263,7 @@ Transform last modified: {Transform(uid).LastModifiedTick}");
 
         HashSet<ushort> netComps = new();
 
-        foreach (var (netId, component) in EntityManager.GetNetComponents(entityUid))
+        foreach (var (netId, component) in meta.NetComponents)
         {
             if (!component.NetSyncEnabled)
                 continue;

Robust.Server/GameStates/RobustTree.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
+using System.Runtime.InteropServices;
 using Microsoft.Extensions.ObjectPool;
 using Robust.Shared.Utility;
 
@@ -89,56 +89,76 @@ public sealed class RobustTree<T> where T : notnull
         throw new InvalidOperationException("Node neither had a parent nor was a RootNode.");
     }
 
-    public TreeNode Set(T rootNode)
+    public void Set(T rootNode)
     {
-        //root node, for now
-        if (_nodeIndex.TryGetValue(rootNode, out var node))
+        ref var node = ref CollectionsMarshal.GetValueRefOrAddDefault(_nodeIndex, rootNode, out var exists);
+
+        if (exists)
         {
             if(!RootNodes.Contains(rootNode))
                 throw new InvalidOperationException("Node already exists as non-root node.");
-            return node;
+            return;
         }
 
         node = new TreeNode(rootNode);
-        _nodeIndex.Add(rootNode, node);
-        RootNodes.Add(rootNode);
-        return node;
+        if(!RootNodes.Add(rootNode))
+            throw new InvalidOperationException("Non-existent node was already a root node?");
     }
 
-    public TreeNode Set(T child, T parent)
+    public void Set(T child, T parent)
     {
-        if (!_nodeIndex.TryGetValue(parent, out var parentNode))
-            parentNode = Set(parent);
-
-        if (parentNode.Children == null)
+        // Code block for where parentNode is a valid ref
         {
-            _nodeIndex[parent] = parentNode = parentNode.WithChildren(_pool.Get());
-        }
+            ref var parentNode = ref CollectionsMarshal.GetValueRefOrAddDefault(_nodeIndex, parent, out var parentExists);
 
-        if (_nodeIndex.TryGetValue(child, out var existingNode))
-        {
-            if (RootNodes.Contains(child))
+            // If parent does not exist we make it a new root node.
+            if (!parentExists)
             {
-                parentNode.Children!.Add(existingNode.Value);
-                RootNodes.Remove(child);
-                _parents.Add(child, parent);
-                return existingNode;
+                parentNode = new TreeNode(parent);
+                if (!RootNodes.Add(parent))
+                {
+                    _nodeIndex.Remove(parent);
+                    throw new InvalidOperationException("Non-existent node was already a root node?");
+                }
             }
 
-            if (!_parents.TryGetValue(child, out var previousParent) || _nodeIndex.TryGetValue(previousParent, out var previousParentNode))
-                throw new InvalidOperationException("Could not find old parent for non-root node.");
-
-            previousParentNode.Children?.Remove(existingNode.Value);
-            parentNode.Children!.Add(existingNode.Value);
-            _parents[child] = parent;
-            return existingNode;
+            var children = parentNode.Children;
+            if (children == null)
+            {
+                children = _pool.Get();
+                parentNode = parentNode.WithChildren(children);
+                DebugTools.AssertNotNull(_nodeIndex[parent].Children);
+            }
+            children.Add(child);
         }
 
-        existingNode = new TreeNode(child);
-        _nodeIndex.Add(child, existingNode);
-        parentNode.Children!.Add(existingNode.Value);
-        _parents.Add(child, parent);
-        return existingNode;
+        // No longer safe to access parentNode ref after this.
+
+        ref var node = ref CollectionsMarshal.GetValueRefOrAddDefault(_nodeIndex, child, out var childExists);
+        if (!childExists)
+        {
+            // This is the path that PVS should take 99% of the time.
+            node = new TreeNode(child);
+            _parents.Add(child, parent);
+            return;
+        }
+
+        if (RootNodes.Remove(child))
+        {
+            DebugTools.Assert(!_parents.ContainsKey(child));
+            _parents.Add(child, parent);
+            return;
+        }
+
+        ref var parentEntry = ref CollectionsMarshal.GetValueRefOrAddDefault(_parents, child, out var previousParentExists);
+        if (!previousParentExists || !_nodeIndex.TryGetValue(parentEntry!, out var previousParentNode))
+        {
+            parentEntry = parent;
+            throw new InvalidOperationException("Could not find old parent for non-root node.");
+        }
+
+        previousParentNode.Children?.Remove(child);
+        parentEntry = parent;
     }
 
     public readonly struct TreeNode : IEquatable<TreeNode>

Robust.Server/GameStates/ServerGameStateManager.cs

@@ -24,6 +24,7 @@ using SharpZstd.Interop;
 using Microsoft.Extensions.ObjectPool;
 using Prometheus;
 using Robust.Server.Replays;
+using Robust.Shared.Console;
 using Robust.Shared.Map.Components;
 using Robust.Shared.Players;
 
@@ -48,6 +49,7 @@ namespace Robust.Server.GameStates
         [Dependency] private readonly IServerEntityNetworkManager _entityNetworkManager = default!;
         [Dependency] private readonly IConfigurationManager _cfg = default!;
         [Dependency] private readonly IParallelManager _parallelMgr = default!;
+        [Dependency] private readonly IConsoleHost _conHost = default!;
 
         private static readonly Histogram _usageHistogram = Metrics.CreateHistogram("robust_game_state_update_usage",
             "Amount of time spent processing different parts of the game state update", new HistogramConfiguration
@@ -83,6 +85,25 @@ namespace Robust.Server.GameStates
             _parallelMgr.AddAndInvokeParallelCountChanged(ResetParallelism);
 
             _cfg.OnValueChanged(CVars.NetPVSCompressLevel, _ => ResetParallelism(), true);
+
+            // temporary command for debugging PVS bugs.
+            _conHost.RegisterCommand("print_pvs_ack", PrintPvsAckInfo);
+        }
+
+        private void PrintPvsAckInfo(IConsoleShell shell, string argstr, string[] args)
+        {
+            var ack = _pvs.PlayerData.Min(x => x.Value.LastReceivedAck);
+            var players = _pvs.PlayerData
+                .Where(x => x.Value.LastReceivedAck == ack)
+                .Select(x => x.Key)
+                .Select(x => $"{x.Name} ({_entityManager.ToPrettyString(x.AttachedEntity)})");
+
+            shell.WriteLine($@"Current tick: {_gameTiming.CurTick}
+Stored oldest acked tick: {_lastOldestAck}
+Deletion history size: {_pvs.EntityPVSCollection.GetDeletedIndices(GameTick.First)?.Count ?? 0}
+Actual oldest: {ack}
+Oldest acked clients: {string.Join(", ", players)}
+");
         }
 
         private void ResetParallelism()
@@ -147,15 +168,6 @@ namespace Robust.Server.GameStates
         /// <inheritdoc />
         public void SendGameStateUpdate()
         {
-            if (!_networkManager.IsConnected)
-            {
-                // Prevent deletions piling up if we have no clients.
-                _pvs.CullDeletionHistory(GameTick.MaxValue);
-                _mapManager.CullDeletionHistory(GameTick.MaxValue);
-                _pvs.CleanupDirty(Enumerable.Empty<IPlayerSession>());
-                return;
-            }
-
             var players = _playerManager.ServerSessions.Where(o => o.Status == SessionStatus.InGame).ToArray();
 
             // Update entity positions in PVS chunks/collections
@@ -195,14 +207,21 @@ namespace Robust.Server.GameStates
                 _pvs.CleanupDirty(players);
             }
 
-            // keep the deletion history buffers clean
-            if (oldestAck > _lastOldestAck)
+            if (oldestAck == GameTick.MaxValue)
             {
-                using var _ = _usageHistogram.WithLabels("Cull History").NewTimer();
-                _lastOldestAck = oldestAck;
-                _pvs.CullDeletionHistory(oldestAck);
-                _mapManager.CullDeletionHistory(oldestAck);
+                // There were no connected players?
+                // In that case we just clear all deletion history.
+                _pvs.CullDeletionHistory(GameTick.MaxValue);
+                _lastOldestAck = GameTick.Zero;
+                return;
             }
+
+            if (oldestAck == _lastOldestAck)
+                return;
+
+            _lastOldestAck = oldestAck;
+            using var __ = _usageHistogram.WithLabels("Cull History").NewTimer();
+            _pvs.CullDeletionHistory(oldestAck);
         }
 
         private GameTick SendStates(IPlayerSession[] players, PvsData? pvsData)

Robust.Server/Prototypes/ServerPrototypeManager.cs

@@ -51,6 +51,7 @@ namespace Robust.Server.Prototypes
 
         public override void LoadDefaultPrototypes(Dictionary<Type, HashSet<string>>? changed = null)
         {
+            LoadDirectory(new("/EnginePrototypes/"), changed: changed);
             LoadDirectory(_server.Options.PrototypeDirectory, changed: changed);
             ResolveResults();
         }

Robust.Shared.CompNetworkGenerator/ComponentNetworkGenerator.cs

@@ -16,12 +16,15 @@ namespace Robust.Shared.CompNetworkGenerator
         private const string MemberAttributeName = "Robust.Shared.Analyzers.AutoNetworkedFieldAttribute";
         private const string GlobalEntityUidName = "global::Robust.Shared.GameObjects.EntityUid";
         private const string GlobalNullableEntityUidName = "global::Robust.Shared.GameObjects.EntityUid?";
-        private const string GlobalEntityCoordinatesName = "global::Robust.Shared.Map.EntityCoordinates?";
-        private const string GlobalNullableEntityCoordinatesName = "global::Robust.Shared.Map.EntityCoordinates";
+        private const string GlobalEntityCoordinatesName = "global::Robust.Shared.Map.EntityCoordinates";
+        private const string GlobalNullableEntityCoordinatesName = "global::Robust.Shared.Map.EntityCoordinates?";
+        private const string GlobalEntityUidSetName = "global::System.Collections.Generic.HashSet<global::Robust.Shared.GameObjects.EntityUid>";
+        private const string GlobalNetEntityUidSetName = "global::System.Collections.Generic.HashSet<global::Robust.Shared.GameObjects.NetEntity>";
+        private const string GlobalEntityUidListName = "global::System.Collections.Generic.List<global::Robust.Shared.GameObjects.EntityUid>";
+        private const string GlobalNetEntityUidListName = "global::System.Collections.Generic.List<global::Robust.Shared.GameObjects.NetEntity>";
 
         private static string GenerateSource(in GeneratorExecutionContext context, INamedTypeSymbol classSymbol, CSharpCompilation comp, bool raiseAfterAutoHandle)
         {
-            // Debugger.Launch();
             var nameSpace = classSymbol.ContainingNamespace.ToDisplayString();
             var componentName = classSymbol.Name;
             var stateName = $"{componentName}_AutoState";
@@ -172,6 +175,26 @@ namespace Robust.Shared.CompNetworkGenerator
             component.{name} = state.{name};");
                         }
 
+                        break;
+                    case GlobalEntityUidSetName:
+                        stateFields.Append($@"
+        public {GlobalNetEntityUidSetName} {name} = default!;");
+
+                        getStateInit.Append($@"
+                {name} = GetNetEntitySet(component.{name}),");
+                        handleStateSetters.Append($@"
+            component.{name} = EnsureEntitySet<{componentName}>(state.{name}, uid);");
+
+                        break;
+                    case GlobalEntityUidListName:
+                        stateFields.Append($@"
+        public {GlobalNetEntityUidListName} {name} = default!;");
+
+                        getStateInit.Append($@"
+                {name} = GetNetEntityList(component.{name}),");
+                        handleStateSetters.Append($@"
+            component.{name} = EnsureEntityList<{componentName}>(state.{name}, uid);");
+
                         break;
                 }
             }

Robust.Shared.Maths/Box2.cs

@@ -2,6 +2,7 @@ using System;
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
 using JetBrains.Annotations;
 using Robust.Shared.Utility;
 
@@ -35,9 +36,15 @@ namespace Robust.Shared.Maths
         /// </summary>
         [FieldOffset(sizeof(float) * 3)] public float Top;
 
+        [NonSerialized]
         [FieldOffset(sizeof(float) * 0)] public Vector2 BottomLeft;
+
+        [NonSerialized]
         [FieldOffset(sizeof(float) * 2)] public Vector2 TopRight;
 
+        [NonSerialized]
+        [FieldOffset(sizeof(float) * 0)] public System.Numerics.Vector4 AsVector4;
+
         public readonly Vector2 BottomRight
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -141,6 +148,11 @@ namespace Robust.Shared.Maths
             return new Box2(min, max);
         }
 
+        public readonly bool HasNan()
+        {
+            return Vector128.EqualsAny(AsVector4.AsVector128(), Vector128.Create(float.NaN));
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         [Pure]
         public readonly bool Intersects(in Box2 other)

Robust.Shared/Containers/BaseContainer.cs

@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;
+using Robust.Shared.Log;
 using Robust.Shared.Serialization;
 
 namespace Robust.Shared.Containers
@@ -111,6 +112,7 @@ namespace Robust.Shared.Containers
             DebugTools.Assert(ownerTransform == null || ownerTransform.Owner == Owner);
             DebugTools.Assert(physics == null || physics.Owner == toinsert);
             DebugTools.Assert(!ExpectedEntities.Contains(entMan.GetNetEntity(toinsert)));
+            DebugTools.Assert(Manager.Containers.ContainsKey(ID));
 
             var physicsQuery = entMan.GetEntityQuery<PhysicsComponent>();
             var transformQuery = entMan.GetEntityQuery<TransformComponent>();
@@ -121,6 +123,26 @@ namespace Robust.Shared.Containers
             var jointSys = entMan.EntitySysManager.GetEntitySystem<SharedJointSystem>();
             var containerSys = entMan.EntitySysManager.GetEntitySystem<SharedContainerSystem>();
 
+            // If someone is attempting to insert an entity into a container that is getting deleted, then we will
+            // automatically delete that entity. I.e., the insertion automatically "succeeds" and both entities get deleted.
+            // This is consistent with what happens if you attempt to attach an entity to a terminating parent.
+
+            if (!entMan.TryGetComponent(Owner, out MetaDataComponent? ownerMeta))
+            {
+                Logger.ErrorS("container",
+                    $"Attempted to insert an entity {entMan.ToPrettyString(toinsert)} into a non-existent entity.");
+                entMan.QueueDeleteEntity(toinsert);
+                return false;
+            }
+
+            if (ownerMeta.EntityLifeStage >= EntityLifeStage.Terminating)
+            {
+                Logger.ErrorS("container",
+                    $"Attempted to insert an entity {entMan.ToPrettyString(toinsert)} into an entity that is terminating. Entity: {entMan.ToPrettyString(Owner)}.");
+                entMan.QueueDeleteEntity(toinsert);
+                return false;
+            }
+
             //Verify we can insert into this container
             if (!force && !containerSys.CanInsert(toinsert, this))
                 return false;

Robust.Shared/GameObjects/ComponentEventArgs.cs

@@ -46,10 +46,13 @@ namespace Robust.Shared.GameObjects
 
         public readonly bool Terminating;
 
-        public RemovedComponentEventArgs(ComponentEventArgs baseArgs, bool terminating)
+        public readonly MetaDataComponent Meta;
+
+        public RemovedComponentEventArgs(ComponentEventArgs baseArgs, bool terminating, MetaDataComponent meta)
         {
             BaseArgs = baseArgs;
             Terminating = terminating;
+            Meta = meta;
         }
     }
 

Robust.Shared/GameObjects/Components/Light/SharedPointLightComponent.cs

@@ -1,9 +1,11 @@
+using System;
 using Robust.Shared.Animations;
 using Robust.Shared.GameStates;
 using Robust.Shared.Maths;
 using Robust.Shared.Serialization.Manager.Attributes;
 using Robust.Shared.ViewVariables;
 using System.Numerics;
+using Robust.Shared.IoC;
 
 namespace Robust.Shared.GameObjects
 {
@@ -39,16 +41,35 @@ namespace Robust.Shared.GameObjects
 
         [Access(typeof(SharedPointLightSystem))]
         [DataField("enabled")]
+        public bool Enabled = true;
+
+        // TODO ECS animations
         [Animatable]
-        public bool Enabled { get; set; } = true;
+        public bool AnimatedEnable
+        {
+            [Obsolete]
+            get => Enabled;
+
+            [Obsolete]
+            set => IoCManager.Resolve<IEntityManager>().System<SharedPointLightSystem>().SetEnabled(Owner, value, this);
+        }
+
+        // TODO ECS animations
+        [Animatable]
+        public float AnimatedRadius
+        {
+            [Obsolete]
+            get => Radius;
+            [Obsolete]
+            set => IoCManager.Resolve<IEntityManager>().System<SharedPointLightSystem>().SetRadius(Owner, value, this);
+        }
 
         /// <summary>
         /// How far the light projects.
         /// </summary>
         [DataField("radius")]
         [Access(typeof(SharedPointLightSystem))]
-        [Animatable]
-        public float Radius { get; set; } = 5f;
+        public float Radius = 5f;
 
         [ViewVariables]
         public bool ContainerOccluded;

Robust.Shared/GameObjects/Components/MetaDataComponent.cs

@@ -8,6 +8,7 @@ using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 using System;
+using System.Collections.Generic;
 
 namespace Robust.Shared.GameObjects
 {
@@ -63,6 +64,12 @@ namespace Robust.Shared.GameObjects
         [DataField("desc")] internal string? _entityDescription;
         internal EntityPrototype? _entityPrototype;
 
+        /// <summary>
+        /// The components attached to the entity that are currently networked.
+        /// </summary>
+        [ViewVariables]
+        internal readonly Dictionary<ushort, Component> NetComponents = new();
+
         /// <summary>
         /// Network identifier for this entity.
         /// </summary>
@@ -87,7 +94,8 @@ namespace Robust.Shared.GameObjects
         public GameTick LastStateApplied { get; internal set; } = GameTick.Zero;
 
         /// <summary>
-        ///     This is the most recent tick at which some component was removed from this entity.
+        ///     This is the most recent tick at which a networked component was removed from this entity.
+        ///     Currently only reliable server-side, client side prediction may cause the value to be wrong.
         /// </summary>
         [ViewVariables]
         public GameTick LastComponentRemoved { get; internal set; } = GameTick.Zero;
@@ -181,15 +189,8 @@ namespace Robust.Shared.GameObjects
         /// <remarks>
         ///     Every entity will always have the first bit set to true.
         /// </remarks>
-        [Access(typeof(MetaDataSystem))]
-        public int VisibilityMask = 1;
-
-        [UsedImplicitly, ViewVariables(VVAccess.ReadWrite)]
-        private int VVVisibilityMask
-        {
-            get => VisibilityMask;
-            set => IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<MetaDataSystem>().SetVisibilityMask(Owner, value, this);
-        }
+        [ViewVariables] // TODO ACCESS RRestrict writing to server-side visibility system
+        public int VisibilityMask { get; internal set; }= 1;
 
         [ViewVariables]
         public bool EntityPaused => PauseTime != null;

Robust.Shared/GameObjects/EntityManager.Components.cs

@@ -4,6 +4,7 @@ using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using JetBrains.Annotations;
 using Robust.Shared.GameStates;
 using Robust.Shared.Log;
@@ -35,9 +36,6 @@ namespace Robust.Shared.GameObjects
 
         private static readonly ComponentState DefaultComponentState = new();
 
-        private readonly Dictionary<EntityUid, Dictionary<ushort, Component>> _netComponents
-            = new(EntityCapacity);
-
         private readonly Dictionary<Type, Dictionary<EntityUid, Component>> _entTraitDict
             = new();
 
@@ -70,7 +68,6 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         public void ClearComponents()
         {
-            _netComponents.Clear();
             _entCompIndex.Clear();
             _deleteSet.Clear();
             foreach (var dict in _entTraitDict.Values)
@@ -175,13 +172,13 @@ namespace Robust.Shared.GameObjects
             }
         }
 
-        public Component AddComponent(EntityUid uid, ushort netId)
+        public Component AddComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null)
         {
             var newComponent = (Component)_componentFactory.GetComponent(netId);
 #pragma warning disable CS0618 // Type or member is obsolete
             newComponent.Owner = uid;
 #pragma warning restore CS0618 // Type or member is obsolete
-            AddComponent(uid, newComponent);
+            AddComponent(uid, newComponent, metadata: meta);
             return newComponent;
         }
 
@@ -249,7 +246,7 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
-        public void AddComponent<T>(EntityUid uid, T component, bool overwrite = false) where T : Component
+        public void AddComponent<T>(EntityUid uid, T component, bool overwrite = false, MetaDataComponent? metadata = null) where T : Component
         {
             if (!uid.IsValid() || !EntityExists(uid))
                 throw new ArgumentException($"Entity {uid} is not valid.", nameof(uid));
@@ -267,35 +264,51 @@ namespace Robust.Shared.GameObjects
             }
 #pragma warning restore CS0618 // Type or member is obsolete
 
-            AddComponentInternal(uid, component, overwrite, false);
+            AddComponentInternal(uid, component, overwrite, false, metadata);
         }
 
-        private void AddComponentInternal<T>(EntityUid uid, T component, bool overwrite, bool skipInit) where T : Component
+        private void AddComponentInternal<T>(EntityUid uid, T component, bool overwrite, bool skipInit, MetaDataComponent? metadata = null) where T : Component
+        {
+            // get interface aliases for mapping
+            var reg = _componentFactory.GetRegistration(component);
+            AddComponentInternal(uid, component, reg, overwrite, skipInit, metadata);
+        }
+
+        private void AddComponentInternal<T>(EntityUid uid, T component, ComponentRegistration reg, bool overwrite, bool skipInit, MetaDataComponent? metadata = null) where T : Component
         {
             // We can't use typeof(T) here in case T is just Component
             DebugTools.Assert(component is MetaDataComponent ||
-                GetComponent<MetaDataComponent>(uid).EntityLifeStage < EntityLifeStage.Terminating,
+                              (metadata ?? MetaQuery.GetComponent(uid)).EntityLifeStage < EntityLifeStage.Terminating,
                 $"Attempted to add a {component.GetType().Name} component to an entity ({ToPrettyString(uid)}) while it is terminating");
 
-            // get interface aliases for mapping
-            var reg = _componentFactory.GetRegistration(component);
-
             // Check that there is no existing component.
             var type = reg.Idx;
             var dict = _entTraitArray[type.Value];
             DebugTools.Assert(dict != null);
 
-            if (dict.TryGetValue(uid, out var duplicate))
+            // Code block to restrict access to ref comp.
             {
-                if (!overwrite && !duplicate.Deleted)
-                    throw new InvalidOperationException(
-                        $"Component reference type {component.GetType().Name} already occupied by {duplicate}");
+                ref var comp = ref CollectionsMarshal.GetValueRefOrAddDefault(dict, uid, out var exists);
+                if (exists)
+                {
+                    if (!overwrite && !comp!.Deleted)
+                    {
+                        throw new InvalidOperationException(
+                            $"Component reference type {reg.Name} already occupied by {comp}");
+                    }
 
-                RemoveComponentImmediate(duplicate, uid, false);
+                    // This will invalidate the comp ref as it removes the key from the dictionary.
+                    // This is inefficient, but component overriding rarely ever happens.
+                    RemoveComponentImmediate(comp!, uid, false, metadata);
+                    dict.Add(uid, component);
+                }
+                else
+                {
+                    comp = component;
+                }
             }
 
             // actually ADD the component
-            dict.Add(uid, component);
             _entCompIndex.Add(uid, component);
 
             // add the component to the netId grid
@@ -303,14 +316,8 @@ namespace Robust.Shared.GameObjects
             {
                 // the main comp grid keeps this in sync
                 var netId = reg.NetID.Value;
-
-                if (!_netComponents.TryGetValue(uid, out var netSet))
-                {
-                    netSet = new Dictionary<ushort, Component>(NetComponentCapacity);
-                    _netComponents.Add(uid, netSet);
-                }
-
-                netSet.Add(netId, component);
+                metadata ??= MetaQuery.GetComponentInternal(uid);
+                metadata.NetComponents.Add(netId, component);
             }
             else
             {
@@ -326,7 +333,7 @@ namespace Robust.Shared.GameObjects
             if (skipInit)
                 return;
 
-            var metadata = GetComponent<MetaDataComponent>(uid);
+            metadata ??= MetaQuery.GetComponentInternal(uid);
 
             if (!metadata.EntityInitialized && !metadata.EntityInitializing)
                 return;
@@ -345,45 +352,48 @@ namespace Robust.Shared.GameObjects
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool RemoveComponent<T>(EntityUid uid)
+        public bool RemoveComponent<T>(EntityUid uid, MetaDataComponent? meta = null)
         {
-            return RemoveComponent(uid, typeof(T));
+            return RemoveComponent(uid, typeof(T), meta);
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool RemoveComponent(EntityUid uid, Type type)
+        public bool RemoveComponent(EntityUid uid, Type type, MetaDataComponent? meta = null)
         {
             if (!TryGetComponent(uid, type, out var comp))
                 return false;
 
-            RemoveComponentImmediate((Component)comp, uid, false);
+            RemoveComponentImmediate((Component)comp, uid, false, meta);
             return true;
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool RemoveComponent(EntityUid uid, ushort netId)
+        public bool RemoveComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null)
         {
-            if (!TryGetComponent(uid, netId, out var comp))
+            if (!MetaQuery.Resolve(uid, ref meta))
                 return false;
 
-            RemoveComponentImmediate((Component)comp, uid, false);
+            if (!TryGetComponent(uid, netId, out var comp, meta))
+                return false;
+
+            RemoveComponentImmediate((Component)comp, uid, false, meta);
             return true;
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RemoveComponent(EntityUid uid, IComponent component)
+        public void RemoveComponent(EntityUid uid, IComponent component, MetaDataComponent? meta = null)
         {
-            RemoveComponent(uid, (Component)component);
+            RemoveComponent(uid, (Component)component, meta);
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public void RemoveComponent(EntityUid uid, Component component)
+        public void RemoveComponent(EntityUid uid, Component component, MetaDataComponent? meta = null)
         {
-            RemoveComponentImmediate(component, uid, false);
+            RemoveComponentImmediate(component, uid, false, meta);
         }
 
         /// <inheritdoc />
@@ -405,9 +415,12 @@ namespace Robust.Shared.GameObjects
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool RemoveComponentDeferred(EntityUid uid, ushort netId)
+        public bool RemoveComponentDeferred(EntityUid uid, ushort netId, MetaDataComponent? meta = null)
         {
-            if (!TryGetComponent(uid, netId, out var comp))
+            if (!MetaQuery.Resolve(uid, ref meta))
+                return false;
+
+            if (!TryGetComponent(uid, netId, out var comp, meta))
                 return false;
 
             RemoveComponentDeferred((Component)comp, uid, false);
@@ -443,22 +456,28 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
-        public void RemoveComponents(EntityUid uid)
+        public void RemoveComponents(EntityUid uid, MetaDataComponent? meta = null)
         {
+            if (!MetaQuery.Resolve(uid, ref meta))
+                return;
+
             foreach (var comp in InSafeOrder(_entCompIndex[uid]))
             {
-                RemoveComponentImmediate(comp, uid, false);
+                RemoveComponentImmediate(comp, uid, false, meta);
             }
         }
 
         /// <inheritdoc />
-        public void DisposeComponents(EntityUid uid)
+        public void DisposeComponents(EntityUid uid, MetaDataComponent? meta = null)
         {
+            if (!MetaQuery.Resolve(uid, ref meta))
+                return;
+
             foreach (var comp in InSafeOrder(_entCompIndex[uid]))
             {
                 try
                 {
-                    RemoveComponentImmediate(comp, uid, true);
+                    RemoveComponentImmediate(comp, uid, true, meta);
                 }
                 catch (Exception)
                 {
@@ -467,7 +486,6 @@ namespace Robust.Shared.GameObjects
             }
 
             _entCompIndex.Remove(uid);
-            _netComponents.Remove(uid);
         }
 
         private void RemoveComponentDeferred(Component component, EntityUid uid, bool terminating)
@@ -508,7 +526,8 @@ namespace Robust.Shared.GameObjects
 #endif
         }
 
-        private void RemoveComponentImmediate(Component component, EntityUid uid, bool terminating)
+        private void RemoveComponentImmediate(Component component, EntityUid uid, bool terminating,
+            MetaDataComponent? meta)
         {
             if (component.Deleted)
             {
@@ -541,10 +560,7 @@ namespace Robust.Shared.GameObjects
                 _runtimeLog.LogException(e, nameof(RemoveComponentImmediate));
             }
 #endif
-            var eventArgs = new RemovedComponentEventArgs(new ComponentEventArgs(component, uid), terminating);
-            ComponentRemoved?.Invoke(eventArgs);
-            _eventBus.OnComponentRemoved(eventArgs);
-            DeleteComponent(uid, component, terminating);
+            DeleteComponent(uid, component, terminating, meta);
         }
 
         /// <inheritdoc />
@@ -579,30 +595,34 @@ namespace Robust.Shared.GameObjects
                 _runtimeLog.LogException(e, nameof(CullRemovedComponents));
             }
 #endif
-                var eventArgs = new RemovedComponentEventArgs(new ComponentEventArgs(component, uid), false);
-                ComponentRemoved?.Invoke(eventArgs);
-                _eventBus.OnComponentRemoved(eventArgs);
-
                 DeleteComponent(uid, component, false);
             }
 
             _deleteSet.Clear();
         }
 
-        private void DeleteComponent(EntityUid entityUid, Component component, bool terminating)
+        private void DeleteComponent(EntityUid entityUid, Component component, bool terminating, MetaDataComponent? metadata = null)
         {
-            var type = component.GetType();
-            var reg = _componentFactory.GetRegistration(type);
+            if (!MetaQuery.ResolveInternal(entityUid, ref metadata))
+                return;
 
-            if (!terminating && reg.NetID != null && _netComponents.TryGetValue(entityUid, out var netSet))
+            var eventArgs = new RemovedComponentEventArgs(new ComponentEventArgs(component, entityUid), false, metadata);
+            ComponentRemoved?.Invoke(eventArgs);
+            _eventBus.OnComponentRemoved(eventArgs);
+
+            var reg = _componentFactory.GetRegistration(component);
+            DebugTools.Assert(component.Networked == (reg.NetID != null));
+
+            if (!terminating && reg.NetID != null)
             {
-                if (netSet.Count == 1)
-                    _netComponents.Remove(entityUid);
-                else
-                    netSet.Remove(reg.NetID.Value);
+                if (!metadata.NetComponents.Remove(reg.NetID.Value))
+                    _sawmill.Error($"Entity {ToPrettyString(entityUid, metadata)} did not have {component.GetType().Name} in its networked component dictionary during component deletion.");
 
                 if (component.NetSyncEnabled)
-                    DirtyEntity(entityUid);
+                {
+                    DirtyEntity(entityUid, metadata);
+                    metadata.LastComponentRemoved = _gameTiming.CurTick;
+                }
             }
 
             _entTraitArray[reg.Idx.Value].Remove(entityUid);
@@ -610,6 +630,10 @@ namespace Robust.Shared.GameObjects
             // TODO if terminating the entity, maybe defer this?
             // _entCompIndex.Remove(uid) gets called later on anyways.
             _entCompIndex.Remove(entityUid, component);
+
+
+            DebugTools.Assert(_netMan.IsClient // Client side prediction can set LastComponentRemoved to some future tick,
+                              || metadata.EntityLastModifiedTick >= metadata.LastComponentRemoved);
         }
 
         /// <inheritdoc />
@@ -651,23 +675,25 @@ namespace Robust.Shared.GameObjects
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool HasComponent(EntityUid uid, ushort netId)
+        public bool HasComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null)
         {
-            return _netComponents.TryGetValue(uid, out var netSet)
-                   && netSet.ContainsKey(netId);
+            if (!MetaQuery.Resolve(uid, ref meta))
+                return false;
+
+            return meta.NetComponents.ContainsKey(netId);
         }
 
         /// <inheritdoc />
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public bool HasComponent(EntityUid? uid, ushort netId)
+        public bool HasComponent(EntityUid? uid, ushort netId, MetaDataComponent? meta = null)
         {
             if (!uid.HasValue)
             {
+                DebugTools.AssertNull(meta);
                 return false;
             }
 
-            return _netComponents.TryGetValue(uid.Value, out var netSet)
-                   && netSet.ContainsKey(netId);
+            return HasComponent(uid.Value, netId, meta);
         }
 
         /// <inheritdoc />
@@ -752,9 +778,9 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
-        public IComponent GetComponent(EntityUid uid, ushort netId)
+        public IComponent GetComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null)
         {
-            return _netComponents[uid][netId];
+            return (meta ?? MetaQuery.GetComponentInternal(uid)).NetComponents[netId];
         }
 
         /// <inheritdoc />
@@ -763,7 +789,7 @@ namespace Robust.Shared.GameObjects
             var dict = _entTraitArray[type.Value];
             if (dict.TryGetValue(uid, out var comp))
             {
-                    return comp;
+                return comp;
             }
 
             throw new KeyNotFoundException($"Entity {uid} does not have a component of type {type}");
@@ -868,10 +894,10 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
-        public bool TryGetComponent(EntityUid uid, ushort netId, [MaybeNullWhen(false)] out IComponent component)
+        public bool TryGetComponent(EntityUid uid, ushort netId, [MaybeNullWhen(false)] out IComponent component, MetaDataComponent? meta = null)
         {
-            if (_netComponents.TryGetValue(uid, out var netSet)
-                && netSet.TryGetValue(netId, out var comp))
+            if (MetaQuery.TryGetComponentInternal(uid, out var metadata)
+                && metadata.NetComponents.TryGetValue(netId, out var comp))
             {
                 component = comp;
                 return true;
@@ -883,23 +909,16 @@ namespace Robust.Shared.GameObjects
 
         /// <inheritdoc />
         public bool TryGetComponent([NotNullWhen(true)] EntityUid? uid, ushort netId,
-            [MaybeNullWhen(false)] out IComponent component)
+            [MaybeNullWhen(false)] out IComponent component, MetaDataComponent? meta = null)
         {
             if (!uid.HasValue)
             {
+                DebugTools.AssertNull(meta);
                 component = default;
                 return false;
             }
 
-            if (_netComponents.TryGetValue(uid.Value, out var netSet)
-                && netSet.TryGetValue(netId, out var comp))
-            {
-                component = comp;
-                return true;
-            }
-
-            component = default;
-            return false;
+            return TryGetComponent(uid.Value, netId, out component, meta);
         }
 
         public EntityQuery<TComp1> GetEntityQuery<TComp1>() where TComp1 : Component
@@ -967,17 +986,18 @@ namespace Robust.Shared.GameObjects
         }
 
         /// <inheritdoc />
-        public NetComponentEnumerable GetNetComponents(EntityUid uid)
+        public NetComponentEnumerable GetNetComponents(EntityUid uid, MetaDataComponent? meta = null)
         {
-            return new NetComponentEnumerable(_netComponents[uid]);
+            meta ??= MetaQuery.GetComponentInternal(uid);
+            return new NetComponentEnumerable(meta.NetComponents);
         }
 
         /// <inheritdoc />
-        public NetComponentEnumerable? GetNetComponentsOrNull(EntityUid uid)
+        public NetComponentEnumerable? GetNetComponentsOrNull(EntityUid uid, MetaDataComponent? meta = null)
         {
-            return _netComponents.TryGetValue(uid, out var data)
-                    ? new NetComponentEnumerable(data)
-                    : null;
+            return MetaQuery.Resolve(uid, ref meta)
+                ? new NetComponentEnumerable(meta.NetComponents)
+                : null;
         }
 
         #region Join Functions

Robust.Shared/GameObjects/EntityManager.Network.cs

@@ -72,6 +72,21 @@ public partial class EntityManager
         return false;
     }
 
+    /// <inheritdoc />
+    public bool TryGetEntityData(NetEntity nEntity, [NotNullWhen(true)] out EntityUid? entity, [NotNullWhen(true)] out MetaDataComponent? meta)
+    {
+        if (NetEntityLookup.TryGetValue(nEntity, out var went))
+        {
+            entity = went.Item1;
+            meta = went.Item2;
+            return true;
+        }
+
+        entity = null;
+        meta = null;
+        return false;
+    }
+
     /// <inheritdoc />
     public bool TryGetEntity(NetEntity? nEntity, [NotNullWhen(true)] out EntityUid? entity)
     {

Robust.Shared/GameObjects/EntityManager.Spawn.cs

@@ -95,7 +95,7 @@ public partial class EntityManager
         ComponentRegistry? overrides = null)
     {
         uid = null;
-        if (!_xformQuery.Resolve(target, ref xform))
+        if (!TransformQuery.Resolve(target, ref xform))
             return false;
 
         if (!xform.ParentUid.IsValid())
@@ -157,7 +157,7 @@ public partial class EntityManager
 
     public EntityUid SpawnNextToOrDrop(string? protoName, EntityUid target, TransformComponent? xform = null, ComponentRegistry? overrides = null)
     {
-        xform ??= _xformQuery.GetComponent(target);
+        xform ??= TransformQuery.GetComponent(target);
         if (!xform.ParentUid.IsValid())
             return Spawn(protoName);
 
@@ -181,7 +181,7 @@ public partial class EntityManager
              || !container.Insert(uid, this))
         {
 
-            xform ??= _xformQuery.GetComponent(containerUid);
+            xform ??= TransformQuery.GetComponent(containerUid);
             if (xform.ParentUid.IsValid())
                 _xforms.PlaceNextToOrDrop(uid, containerUid, targetXform: xform);
         }

Robust.Shared/GameObjects/EntityManager.cs

@@ -2,9 +2,11 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using Prometheus;
 using Robust.Shared.Log;
 using Robust.Shared.Map;
+using Robust.Shared.Network;
 using Robust.Shared.Profiling;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization.Manager;
@@ -31,13 +33,14 @@ namespace Robust.Shared.GameObjects
         [IoC.Dependency] private readonly IGameTiming _gameTiming = default!;
         [IoC.Dependency] private readonly ISerializationManager _serManager = default!;
         [IoC.Dependency] private readonly ProfManager _prof = default!;
+        [IoC.Dependency] private readonly INetManager _netMan = default!;
 
         // I feel like PJB might shed me for putting a system dependency here, but its required for setting entity
         // positions on spawn....
         private SharedTransformSystem _xforms = default!;
 
-        protected EntityQuery<MetaDataComponent> MetaQuery;
-        private EntityQuery<TransformComponent> _xformQuery;
+        public EntityQuery<MetaDataComponent> MetaQuery;
+        public EntityQuery<TransformComponent> TransformQuery;
 
         #endregion Dependencies
 
@@ -85,6 +88,9 @@ namespace Robust.Shared.GameObjects
 
         private string _xformName = string.Empty;
 
+        private ComponentRegistration _metaReg = default!;
+        private ComponentRegistration _xformReg = default!;
+
         private SharedMapSystem _mapSystem = default!;
 
         private ISawmill _sawmill = default!;
@@ -111,7 +117,9 @@ namespace Robust.Shared.GameObjects
             _eventBus = new EntityEventBus(this);
 
             InitializeComponents();
-            _xformName = _componentFactory.GetComponentName(typeof(TransformComponent));
+            _metaReg = _componentFactory.GetRegistration(typeof(MetaDataComponent));
+            _xformReg = _componentFactory.GetRegistration(typeof(TransformComponent));
+            _xformName = _xformReg.Name;
             _sawmill = LogManager.GetSawmill("entity");
             _resolveSawmill = LogManager.GetSawmill("resolve");
 
@@ -233,7 +241,7 @@ namespace Robust.Shared.GameObjects
             _mapSystem = System<SharedMapSystem>();
             _xforms = System<SharedTransformSystem>();
             MetaQuery = GetEntityQuery<MetaDataComponent>();
-            _xformQuery = GetEntityQuery<TransformComponent>();
+            TransformQuery = GetEntityQuery<TransformComponent>();
         }
 
         public virtual void Shutdown()
@@ -316,7 +324,7 @@ namespace Robust.Shared.GameObjects
         public virtual EntityUid CreateEntityUninitialized(string? prototypeName, EntityCoordinates coordinates, ComponentRegistry? overrides = null)
         {
             var newEntity = CreateEntity(prototypeName, overrides);
-            _xforms.SetCoordinates(newEntity, _xformQuery.GetComponent(newEntity), coordinates, unanchor: false);
+            _xforms.SetCoordinates(newEntity, TransformQuery.GetComponent(newEntity), coordinates, unanchor: false);
             return newEntity;
         }
 
@@ -324,7 +332,7 @@ namespace Robust.Shared.GameObjects
         public virtual EntityUid CreateEntityUninitialized(string? prototypeName, MapCoordinates coordinates, ComponentRegistry? overrides = null)
         {
             var newEntity = CreateEntity(prototypeName, overrides);
-            var transform = _xformQuery.GetComponent(newEntity);
+            var transform = TransformQuery.GetComponent(newEntity);
 
             if (coordinates.MapId == MapId.Nullspace)
             {
@@ -363,18 +371,8 @@ namespace Robust.Shared.GameObjects
         public virtual void DirtyEntity(EntityUid uid, MetaDataComponent? metadata = null)
         {
             // We want to retrieve MetaDataComponent even if its Deleted flag is set.
-            if (metadata == null)
-            {
-                if (!_entTraitArray[CompIdx.ArrayIndex<MetaDataComponent>()].TryGetValue(uid, out var component))
-                    throw new KeyNotFoundException($"Entity {uid} does not exist, cannot dirty it.");
-                metadata = (MetaDataComponent)component;
-            }
-            else
-            {
-#pragma warning disable CS0618
-                DebugTools.Assert(metadata.Owner == uid);
-#pragma warning restore CS0618
-            }
+            if (!MetaQuery.ResolveInternal(uid, ref metadata))
+                return;
 
             if (metadata.EntityLastModifiedTick == _gameTiming.CurTick)
                 return;
@@ -445,7 +443,7 @@ namespace Robust.Shared.GameObjects
             EntityUid uid,
             MetaDataComponent metadata)
         {
-            var transform = _xformQuery.GetComponent(uid);
+            var transform = TransformQuery.GetComponent(uid);
             metadata.EntityLifeStage = EntityLifeStage.Terminating;
 
             try
@@ -477,7 +475,7 @@ namespace Robust.Shared.GameObjects
         {
             // Note about this method: #if EXCEPTION_TOLERANCE is not used here because we're gonna it in the future...
             var netEntity = GetNetEntity(uid, metadata);
-            var transform = _xformQuery.GetComponent(uid);
+            var transform = TransformQuery.GetComponent(uid);
 
             // Detach the base entity to null before iterating over children
             // This also ensures that the entity-lookup updates don't have to be re-run for every child (which recurses up the transform hierarchy).
@@ -559,7 +557,7 @@ namespace Robust.Shared.GameObjects
 
         public bool EntityExists(EntityUid uid)
         {
-            return _entTraitArray[CompIdx.ArrayIndex<MetaDataComponent>()].ContainsKey(uid);
+            return MetaQuery.HasComponentInternal(uid);
         }
 
         public bool EntityExists(EntityUid? uid)
@@ -578,12 +576,12 @@ namespace Robust.Shared.GameObjects
 
         public bool Deleted(EntityUid uid)
         {
-            return !_entTraitArray[CompIdx.ArrayIndex<MetaDataComponent>()].TryGetValue(uid, out var comp) || ((MetaDataComponent) comp).EntityDeleted;
+            return !MetaQuery.TryGetComponentInternal(uid, out var comp) || comp.EntityDeleted;
         }
 
         public bool Deleted([NotNullWhen(false)] EntityUid? uid)
         {
-            return !uid.HasValue || !_entTraitArray[CompIdx.ArrayIndex<MetaDataComponent>()].TryGetValue(uid.Value, out var comp) || ((MetaDataComponent) comp).EntityDeleted;
+            return !uid.HasValue || !MetaQuery.TryGetComponentInternal(uid.Value, out var comp) || comp.EntityDeleted;
         }
 
         /// <summary>
@@ -645,10 +643,12 @@ namespace Robust.Shared.GameObjects
 
             Entities.Add(uid);
             // add the required MetaDataComponent directly.
-            AddComponentInternal(uid, metadata, false, false);
+            AddComponentInternal(uid, metadata, _metaReg, false, true, metadata);
 
             // allocate the required TransformComponent
-            AddComponent<TransformComponent>(uid);
+            var xformComp = Unsafe.As<TransformComponent>(_componentFactory.GetComponent(_xformReg));
+            xformComp.Owner = uid;
+            AddComponentInternal(uid, xformComp, false, true, metadata);
 
             return uid;
         }
@@ -706,7 +706,7 @@ namespace Robust.Shared.GameObjects
                 StartEntity(entity);
 
                 // If the map we're initializing the entity on is initialized, run map init on it.
-                if (_mapManager.IsMapInitialized(mapId ?? _xformQuery.GetComponent(entity).MapID))
+                if (_mapManager.IsMapInitialized(mapId ?? TransformQuery.GetComponent(entity).MapID))
                     RunMapInit(entity, meta);
             }
             catch (Exception e)

Robust.Shared/GameObjects/EntitySystem.Proxy.cs

@@ -61,7 +61,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool Deleted(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             return true;
 
         return metaData.EntityDeleted;
@@ -73,7 +73,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TerminatingOrDeleted(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             return true;
 
         return metaData.EntityLifeStage >= EntityLifeStage.Terminating;
@@ -104,7 +104,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected EntityLifeStage LifeStage(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityLifeStage;
@@ -169,7 +169,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryLifeStage(EntityUid uid, [NotNullWhen(true)] out EntityLifeStage? lifeStage, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             lifeStage = null;
             return false;
@@ -227,7 +227,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected string Name(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if(!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityName;
@@ -240,7 +240,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected string Description(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if(!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityDescription;
@@ -253,7 +253,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected EntityPrototype? Prototype(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityPrototype;
@@ -265,7 +265,7 @@ public partial class EntitySystem
     /// <exception cref="KeyNotFoundException">Thrown when the entity doesn't exist.</exception>
     protected GameTick LastModifiedTick(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityLastModifiedTick;
@@ -278,7 +278,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool Paused(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         return metaData.EntityPaused;
@@ -291,7 +291,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected void SetPaused(EntityUid uid, bool paused, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             throw CompNotFound<MetaDataComponent>(uid);
 
         EntityManager.EntitySysManager.GetEntitySystem<MetaDataSystem>().SetEntityPaused(uid, paused, metaData);
@@ -302,12 +302,12 @@ public partial class EntitySystem
     /// </summary>
     /// <returns>Whether the operation succeeded.</returns>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    protected bool TryDirty(EntityUid uid)
+    protected bool TryDirty(EntityUid uid, MetaDataComponent? metaData = null)
     {
-        if (!Exists(uid))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
             return false;
 
-        DirtyEntity(uid);
+        DirtyEntity(uid, metaData);
         return true;
     }
 
@@ -318,7 +318,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryName(EntityUid uid, [NotNullWhen(true)] out string? name, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             name = null;
             return false;
@@ -335,7 +335,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryDescription(EntityUid uid, [NotNullWhen(true)] out string? description, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             description = null;
             return false;
@@ -352,7 +352,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryPrototype(EntityUid uid, [NotNullWhen(true)] out EntityPrototype? prototype, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             prototype = null;
             return false;
@@ -369,7 +369,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryLastModifiedTick(EntityUid uid, [NotNullWhen(true)] out GameTick? lastModifiedTick, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             lastModifiedTick = null;
             return false;
@@ -386,7 +386,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryPaused(EntityUid uid, [NotNullWhen(true)] out bool? paused, MetaDataComponent? metaData = null)
     {
-        if (!Resolve(uid, ref metaData, false))
+        if (!EntityManager.MetaQuery.Resolve(uid, ref metaData, false))
         {
             paused = null;
             return false;
@@ -458,6 +458,20 @@ public partial class EntitySystem
         return EntityManager.TryGetComponent(uid, out comp);
     }
 
+    /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid, out T)"/>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    protected bool TryComp(EntityUid uid, [NotNullWhen(true)] out TransformComponent? comp)
+    {
+        return EntityManager.TransformQuery.TryGetComponent(uid, out comp);
+    }
+
+    /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid, out T)"/>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    protected bool TryComp(EntityUid uid, [NotNullWhen(true)] out MetaDataComponent? comp)
+    {
+        return EntityManager.MetaQuery.TryGetComponent(uid, out comp);
+    }
+
     /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid?, out T)"/>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected bool TryComp<T>([NotNullWhen(true)] EntityUid? uid, [NotNullWhen(true)] out T? comp)
@@ -471,6 +485,30 @@ public partial class EntitySystem
         return EntityManager.TryGetComponent(uid.Value, out comp);
     }
 
+    /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid?, out T)"/>
+    protected bool TryComp([NotNullWhen(true)] EntityUid? uid, [NotNullWhen(true)] out TransformComponent? comp)
+    {
+        if (!uid.HasValue)
+        {
+            comp = default;
+            return false;
+        }
+
+        return EntityManager.TransformQuery.TryGetComponent(uid.Value, out comp);
+    }
+
+    /// <inheritdoc cref="IEntityManager.TryGetComponent&lt;T&gt;(EntityUid?, out T)"/>
+    protected bool TryComp([NotNullWhen(true)] EntityUid? uid, [NotNullWhen(true)] out MetaDataComponent? comp)
+    {
+        if (!uid.HasValue)
+        {
+            comp = default;
+            return false;
+        }
+
+        return EntityManager.MetaQuery.TryGetComponent(uid.Value, out comp);
+    }
+
     /// <inheritdoc cref="IEntityManager.GetComponents"/>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected IEnumerable<IComponent> AllComps(EntityUid uid)
@@ -492,7 +530,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected TransformComponent Transform(EntityUid uid)
     {
-        return EntityManager.GetComponent<TransformComponent>(uid);
+        return EntityManager.TransformQuery.GetComponent(uid);
     }
 
     /// <summary>
@@ -502,7 +540,7 @@ public partial class EntitySystem
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected MetaDataComponent MetaData(EntityUid uid)
     {
-        return EntityManager.GetComponent<MetaDataComponent>(uid);
+        return EntityManager.MetaQuery.GetComponent(uid);
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -511,6 +549,13 @@ public partial class EntitySystem
         return EntityManager.GetEntityData(nuid);
     }
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    protected bool TryGetEntityData(NetEntity nuid, [NotNullWhen(true)] out EntityUid? uid,
+        [NotNullWhen(true)] out MetaDataComponent? meta)
+    {
+        return EntityManager.TryGetEntityData(nuid, out uid, out meta);
+    }
+
     #endregion
 
     #region Component Has
@@ -915,9 +960,9 @@ public partial class EntitySystem
     #region NetEntities
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    protected bool IsClientSide(EntityUid entity)
+    protected bool IsClientSide(EntityUid entity, MetaDataComponent? meta = null)
     {
-        return EntityManager.IsClientSide(entity);
+        return EntityManager.IsClientSide(entity, meta);
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

Robust.Shared/GameObjects/EntitySystem.Resolve.cs

@@ -32,6 +32,22 @@ namespace Robust.Shared.GameObjects
             return found;
         }
 
+        /// <inheritdoc cref="Resolve{TComp}"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected bool Resolve(EntityUid uid, [NotNullWhen(true)] ref MetaDataComponent? component,
+            bool logMissing = true)
+        {
+            return EntityManager.MetaQuery.Resolve(uid, ref component);
+        }
+
+        /// <inheritdoc cref="Resolve{TComp}"/>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected bool Resolve(EntityUid uid, [NotNullWhen(true)] ref TransformComponent? component,
+            bool logMissing = true)
+        {
+            return EntityManager.TransformQuery.Resolve(uid, ref component);
+        }
+
         /// <summary>
         ///     Resolves the components on the entity for the null component references.
         /// </summary>

Robust.Shared/GameObjects/IEntityManager.Components.cs

@@ -49,7 +49,7 @@ namespace Robust.Shared.GameObjects
         /// <summary>
         ///     Adds a Component with a given network id to an entity.
         /// </summary>
-        Component AddComponent(EntityUid uid, ushort netId);
+        Component AddComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Adds an uninitialized Component type to an entity.
@@ -70,7 +70,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity being modified.</param>
         /// <param name="component">Component to add.</param>
         /// <param name="overwrite">Should it overwrite existing components?</param>
-        void AddComponent<T>(EntityUid uid, T component, bool overwrite = false) where T : Component;
+        void AddComponent<T>(EntityUid uid, T component, bool overwrite = false, MetaDataComponent? metadata = null) where T : Component;
 
         /// <summary>
         ///     Removes the component with the specified reference type,
@@ -78,7 +78,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <typeparam name="T">The component reference type to remove.</typeparam>
         /// <param name="uid">Entity UID to modify.</param>
-        bool RemoveComponent<T>(EntityUid uid);
+        bool RemoveComponent<T>(EntityUid uid, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Removes the component with a specified type.
@@ -86,7 +86,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to modify.</param>
         /// <param name="type">A trait or component type to check for.</param>
         /// <returns>Returns false if the entity did not have the specified component.</returns>
-        bool RemoveComponent(EntityUid uid, Type type);
+        bool RemoveComponent(EntityUid uid, Type type, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Removes the component with a specified network ID.
@@ -94,14 +94,14 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to modify.</param>
         /// <param name="netID">Network ID of the component to remove.</param>
         /// <returns>Returns false if the entity did not have the specified component.</returns>
-        bool RemoveComponent(EntityUid uid, ushort netID);
+        bool RemoveComponent(EntityUid uid, ushort netID, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Removes the specified component. Throws if the given component does not belong to the entity.
         /// </summary>
         /// <param name="uid">Entity UID to modify.</param>
         /// <param name="component">Component to remove.</param>
-        void RemoveComponent(EntityUid uid, IComponent component);
+        void RemoveComponent(EntityUid uid, IComponent component, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Immediately shuts down a component, but defers the removal and deletion until the end of the tick.
@@ -125,7 +125,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to modify.</param>
         /// <param name="netID">Network ID of the component to remove.</param>
         /// <returns>Returns false if the entity did not have the specified component.</returns>
-        bool RemoveComponentDeferred(EntityUid uid, ushort netID);
+        bool RemoveComponentDeferred(EntityUid uid, ushort netID, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Immediately shuts down a component, but defers the removal and deletion until the end of the tick.
@@ -147,7 +147,7 @@ namespace Robust.Shared.GameObjects
         ///     Removes all components from an entity, except the required components.
         /// </summary>
         /// <param name="uid">Entity UID to modify.</param>
-        void RemoveComponents(EntityUid uid);
+        void RemoveComponents(EntityUid uid, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Removes ALL components from an entity. This includes the required components,
@@ -155,7 +155,7 @@ namespace Robust.Shared.GameObjects
         ///     used when deleting an entity.
         /// </summary>
         /// <param name="uid">Entity UID to modify.</param>
-        void DisposeComponents(EntityUid uid);
+        void DisposeComponents(EntityUid uid, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Checks if the entity has a component type.
@@ -187,7 +187,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to check.</param>
         /// <param name="type">A trait or component type to check for.</param>
         /// <returns>True if the entity has the component type, otherwise false.</returns>
-        bool HasComponent(EntityUid ?uid, Type type);
+        bool HasComponent(EntityUid? uid, Type type);
 
         /// <summary>
         ///     Checks if the entity has a component with a given network ID. This does not check
@@ -196,7 +196,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to check.</param>
         /// <param name="netId">Network ID to check for.</param>
         /// <returns>True if the entity has a component with the given network ID, otherwise false.</returns>
-        bool HasComponent(EntityUid uid, ushort netId);
+        bool HasComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Checks if the entity has a component with a given network ID. This does not check
@@ -205,7 +205,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to check.</param>
         /// <param name="netId">Network ID to check for.</param>
         /// <returns>True if the entity has a component with the given network ID, otherwise false.</returns>
-        bool HasComponent(EntityUid? uid, ushort netId);
+        bool HasComponent(EntityUid? uid, ushort netId, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     This method will always return a component for a certain entity, adding it if it's not there already.
@@ -255,7 +255,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="uid">Entity UID to look on.</param>
         /// <param name="netId">Network ID of the component to retrieve.</param>
         /// <returns>The component with the specified network id.</returns>
-        IComponent GetComponent(EntityUid uid, ushort netId);
+        IComponent GetComponent(EntityUid uid, ushort netId, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Returns the component of a specific type, even if it has been marked for deletion.
@@ -318,7 +318,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="netId">Component Network ID to check for.</param>
         /// <param name="component">Component with the specified network id.</param>
         /// <returns>If the component existed in the entity.</returns>
-        bool TryGetComponent(EntityUid uid, ushort netId, [NotNullWhen(true)] out IComponent? component);
+        bool TryGetComponent(EntityUid uid, ushort netId, [NotNullWhen(true)] out IComponent? component, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Returns the component with a specified network ID. This does not check
@@ -328,7 +328,7 @@ namespace Robust.Shared.GameObjects
         /// <param name="netId">Component Network ID to check for.</param>
         /// <param name="component">Component with the specified network id.</param>
         /// <returns>If the component existed in the entity.</returns>
-        bool TryGetComponent([NotNullWhen(true)] EntityUid? uid, ushort netId, [NotNullWhen(true)] out IComponent? component);
+        bool TryGetComponent([NotNullWhen(true)] EntityUid? uid, ushort netId, [NotNullWhen(true)] out IComponent? component, MetaDataComponent? meta = null);
 
         /// <summary>
         /// Returns a cached struct enumerator with the specified component.
@@ -364,7 +364,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <param name="uid">Entity UID to look on.</param>
         /// <returns>All components that have a network ID.</returns>
-        NetComponentEnumerable GetNetComponents(EntityUid uid);
+        NetComponentEnumerable GetNetComponents(EntityUid uid, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Returns ALL networked components on an entity, including deleted ones. Returns null if the entity does
@@ -372,7 +372,7 @@ namespace Robust.Shared.GameObjects
         /// </summary>
         /// <param name="uid">Entity UID to look on.</param>
         /// <returns>All components that have a network ID.</returns>
-        public NetComponentEnumerable? GetNetComponentsOrNull(EntityUid uid);
+        public NetComponentEnumerable? GetNetComponentsOrNull(EntityUid uid, MetaDataComponent? meta = null);
 
         /// <summary>
         ///     Gets a component state.

Robust.Shared/GameObjects/IEntityManager.Network.cs

@@ -22,6 +22,12 @@ public partial interface IEntityManager
     /// </summary>
     public bool TryGetEntity(NetEntity? nEntity, [NotNullWhen(true)] out EntityUid? entity);
 
+    /// <summary>
+    /// Tries to returns the corresponding local <see cref="EntityUid"/> along with the metdata component.
+    /// </summary>
+    public bool TryGetEntityData(NetEntity nEntity, [NotNullWhen(true)] out EntityUid? entity,
+        [NotNullWhen(true)] out MetaDataComponent? meta);
+
     /// <summary>
     /// TryGet version of <see cref="GetNetEntity"/>
     /// </summary>

Robust.Shared/GameObjects/NetEntity.cs

@@ -4,6 +4,7 @@ using Robust.Shared.IoC;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization;
 using Robust.Shared.Timing;
+using Robust.Shared.Utility;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Shared.GameObjects;
@@ -47,7 +48,14 @@ public readonly struct NetEntity : IEquatable<NetEntity>, IComparable<NetEntity>
     /// </summary>
     public static NetEntity Parse(ReadOnlySpan<char> uid)
     {
-        return new NetEntity(int.Parse(uid));
+        if (uid[0] != 'c')
+            return new NetEntity(int.Parse(uid));
+
+        if (uid.Length == 1)
+            throw new FormatException($"'c' is not a valid NetEntity");
+
+        var id = int.Parse(uid.Slice(1));
+        return new NetEntity(id | ClientEntity);
     }
 
     public static bool TryParse(ReadOnlySpan<char> uid, out NetEntity entity)
@@ -121,6 +129,9 @@ public readonly struct NetEntity : IEquatable<NetEntity>, IComparable<NetEntity>
     /// <inheritdoc />
     public override string ToString()
     {
+        if (IsClientSide())
+            return $"c{Id & ~ClientEntity}";
+
         return Id.ToString();
     }
 
@@ -135,6 +146,14 @@ public readonly struct NetEntity : IEquatable<NetEntity>, IComparable<NetEntity>
         ReadOnlySpan<char> format,
         IFormatProvider? provider)
     {
+        if (IsClientSide())
+        {
+            return FormatHelpers.TryFormatInto(
+                destination,
+                out charsWritten,
+                $"c{Id & ~ClientEntity}");
+        }
+
         return Id.TryFormat(destination, out charsWritten);
     }
 

Robust.Shared/GameObjects/Systems/MetaDataSystem.cs

@@ -148,12 +148,6 @@ public abstract class MetaDataSystem : EntitySystem
 
         component.Flags &= ~ev.ToRemove;
     }
-
-    public virtual void SetVisibilityMask(EntityUid uid, int value, MetaDataComponent? meta = null)
-    {
-        if (Resolve(uid, ref meta))
-            meta.VisibilityMask = value;
-    }
 }
 
 /// <summary>

Robust.Shared/GameObjects/Systems/SharedTransformSystem.Component.cs

@@ -495,7 +495,7 @@ public abstract partial class SharedTransformSystem
                     throw new InvalidOperationException($"Attempted to parent entity {ToPrettyString(uid)} to non-existent entity {value.EntityId}");
                 }
 
-                if (newParent.LifeStage > ComponentLifeStage.Running || LifeStage(value.EntityId) > EntityLifeStage.MapInitialized)
+                if (newParent.LifeStage >= ComponentLifeStage.Stopping || LifeStage(value.EntityId) >= EntityLifeStage.Terminating)
                 {
                     DetachParentToNull(uid, xform);
                     if (_netMan.IsServer || IsClientSide(uid))

Robust.Shared/Localization/ILocalizationManager.cs

@@ -2,7 +2,6 @@ using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using JetBrains.Annotations;
-using Robust.Shared.ContentPack;
 using Robust.Shared.Serialization;
 
 namespace Robust.Shared.Localization
@@ -23,7 +22,7 @@ namespace Robust.Shared.Localization
     public interface ILocalizationManager
     {
         /// <summary>
-        ///     Gets a language approrpiate string represented by the supplied messageId.
+        ///     Gets a language appropriate string represented by the supplied messageId.
         /// </summary>
         /// <param name="messageId">Unique Identifier for a translated message.</param>
         /// <returns>
@@ -31,6 +30,13 @@ namespace Robust.Shared.Localization
         /// </returns>
         string GetString(string messageId);
 
+        /// <summary>
+        ///     Checks if the specified id has been registered, without checking its arguments.
+        /// </summary>
+        /// <param name="messageId">Unique Identifier for a translated message.</param>
+        /// <returns>true if it exists, even if it requires any parameters to be passed.</returns>
+        bool HasString(string messageId);
+
         /// <summary>
         ///     Try- version of <see cref="GetString(string)"/>
         /// </summary>
@@ -46,7 +52,7 @@ namespace Robust.Shared.Localization
         string GetString(string messageId, params (string, object)[] args);
 
         /// <summary>
-        ///     Try- version of <see cref="GetString(string, ValueTuple{string, object}[])"/>
+        ///     Try- version of <see cref="GetString(string, (string, object)[])"/>
         /// </summary>
         /// <remarks>
         ///     Does not log a warning if the message does not exist.

Robust.Shared/Localization/LocId.cs

@@ -0,0 +1,41 @@
+using System;
+using Robust.Shared.Serialization;
+using Robust.Shared.Serialization.TypeSerializers.Implementations;
+
+namespace Robust.Shared.Localization;
+
+/// <summary>
+///     Wrapper type for a localization string id.
+/// </summary>
+/// <param name="Id">The id of the localization string.</param>
+/// <remarks>
+///     This will be automatically validated by <see cref="LocIdSerializer"/> if used in data fields.</remarks>
+/// <seealso cref="Loc.GetString(string)"/>
+[Serializable, NetSerializable]
+public readonly record struct LocId(string Id) : IEquatable<string>, IComparable<LocId>
+{
+    public static implicit operator string(LocId locId)
+    {
+        return locId.Id;
+    }
+
+    public static implicit operator LocId(string id)
+    {
+        return new LocId(id);
+    }
+
+    public static implicit operator LocId?(string? id)
+    {
+        return id == null ? default(LocId?) : new LocId(id);
+    }
+
+    public bool Equals(string? other)
+    {
+        return Id == other;
+    }
+
+    public int CompareTo(LocId other)
+    {
+        return string.Compare(Id, other.Id, StringComparison.Ordinal);
+    }
+}

Robust.Shared/Localization/LocalizationManager.cs

@@ -4,7 +4,6 @@ using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.IO;
 using System.Linq;
-using JetBrains.Annotations;
 using Linguini.Bundle;
 using Linguini.Bundle.Builder;
 using Linguini.Bundle.Errors;
@@ -55,7 +54,6 @@ namespace Robust.Shared.Localization
             return msg;
         }
 
-
         public string GetString(string messageId, params (string, object)[] args0)
         {
             if (_defaultCulture == null)
@@ -70,6 +68,11 @@ namespace Robust.Shared.Localization
             return msg;
         }
 
+        public bool HasString(string messageId)
+        {
+            return HasMessage(messageId, out _);
+        }
+
         public bool TryGetString(string messageId, [NotNullWhen(true)] out string? value)
         {
             return TryGetString(messageId, out value, null);

Robust.Shared/Physics/Collision/PhysicsHull.cs

@@ -28,7 +28,7 @@ public record struct PhysicsHull()
         e.Normalize();
 
         // discard points left of e and find point furthest to the right of e
-        var rightPoints = new Vector2[PhysicsConstants.MaxPolygonVertices];
+        Span<Vector2> rightPoints = stackalloc Vector2[PhysicsConstants.MaxPolygonVertices];
         var rightCount = 0;
 
         var bestIndex = 0;

Robust.Shared/Physics/DynamicTree.cs

@@ -24,6 +24,8 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.Numerics;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Runtime.Intrinsics;
 using JetBrains.Annotations;
 using Robust.Shared.Maths;
 
@@ -131,7 +133,7 @@ namespace Robust.Shared.Physics
 
             aabb ??= _extractAabb(item);
 
-            if (HasNaNs(aabb.Value))
+            if (aabb.Value.HasNan())
             {
                 _nodeLookup[item] = DynamicTree.Proxy.Free;
                 return true;
@@ -179,28 +181,25 @@ namespace Robust.Shared.Physics
         [MethodImpl(MethodImplOptions.NoInlining)]
         public bool Update(in T item, Box2? newBox = null)
         {
-            if (!TryGetProxy(item, out var proxy))
-            {
+            ref var proxy = ref CollectionsMarshal.GetValueRefOrNullRef(_nodeLookup, item);
+            if (Unsafe.IsNullRef(ref proxy))
                 return false;
-            }
 
             newBox ??= _extractAabb(item);
 
-            if (HasNaNs(newBox.Value))
+            if (newBox.Value.HasNan())
             {
                 if (proxy == DynamicTree.Proxy.Free)
-                {
                     return false;
-                }
 
                 _b2Tree.DestroyProxy(proxy);
-                _nodeLookup[item] = DynamicTree.Proxy.Free;
+                proxy = DynamicTree.Proxy.Free;
                 return true;
             }
 
             if (proxy == DynamicTree.Proxy.Free)
             {
-                _nodeLookup[item] = _b2Tree.CreateProxy(newBox.Value, item);
+                proxy = _b2Tree.CreateProxy(newBox.Value, item);
                 return true;
             }
 
@@ -331,36 +330,30 @@ namespace Robust.Shared.Physics
         public void AddOrUpdate(T item, Box2? aabb = null)
         {
             aabb ??= _extractAabb(item);
-            if (!_nodeLookup.TryGetValue(item, out var proxy))
+
+            ref var proxy = ref CollectionsMarshal.GetValueRefOrAddDefault(_nodeLookup, item, out var exists);
+            if (!exists)
             {
-                _nodeLookup[item] = HasNaNs(aabb.Value) ? DynamicTree.Proxy.Free : _b2Tree.CreateProxy(aabb.Value, item);
+                proxy = aabb.Value.HasNan() ? DynamicTree.Proxy.Free : _b2Tree.CreateProxy(aabb.Value, item);
                 return;
             }
 
-            if (HasNaNs(aabb.Value))
+            if (aabb.Value.HasNan())
             {
                 if (proxy == DynamicTree.Proxy.Free)
                     return;
 
                 _b2Tree.DestroyProxy(proxy);
-                _nodeLookup[item] = DynamicTree.Proxy.Free;
+                proxy = DynamicTree.Proxy.Free;
                 return;
             }
 
             if (proxy == DynamicTree.Proxy.Free)
-                _nodeLookup[item] = _b2Tree.CreateProxy(aabb.Value, item);
+                proxy = _b2Tree.CreateProxy(aabb.Value, item);
             else
                 _b2Tree.MoveProxy(proxy, aabb.Value, Vector2.Zero);
         }
 
-        private static bool HasNaNs(in Box2 box)
-        {
-            return float.IsNaN(box.Left)
-                   || float.IsNaN(box.Top)
-                   || float.IsNaN(box.Bottom)
-                   || float.IsNaN(box.Right);
-        }
-
         [Conditional("DEBUG_DYNAMIC_TREE")]
         [Conditional("DEBUG_DYNAMIC_TREE_ASSERTS")]
         [DebuggerNonUserCode]

Robust.Shared/Physics/Dynamics/Contacts/Contact.cs

@@ -365,5 +365,7 @@ namespace Robust.Shared.Physics.Dynamics.Contacts
         /// Is this a special contact for grid-grid collisions
         /// </summary>
         Grid = 1 << 2,
+
+        Deleting = 1 << 3,
     }
 }

Robust.Shared/Physics/Systems/FixtureSystem.cs

@@ -189,8 +189,6 @@ namespace Robust.Shared.Physics.Systems
                 _lookup.DestroyProxies(uid, fixtureId, fixture, xform, broadphase, physicsMap);
             }
 
-
-
             if (updates)
             {
                 var resetMass = fixture.Density > 0f;

Robust.Shared/Physics/Systems/SharedPhysicsSystem.Contacts.cs

@@ -312,12 +312,17 @@ public abstract partial class SharedPhysicsSystem
 
     public void DestroyContact(Contact contact)
     {
+        // Don't recursive update or we're in for a bad time.
+        if ((contact.Flags & ContactFlags.Deleting) != 0x0)
+            return;
+
         Fixture fixtureA = contact.FixtureA!;
         Fixture fixtureB = contact.FixtureB!;
         var bodyA = contact.BodyA!;
         var bodyB = contact.BodyB!;
         var aUid = contact.EntityA;
         var bUid = contact.EntityB;
+        contact.Flags |= ContactFlags.Deleting;
 
         if (contact.IsTouching)
         {

Robust.Shared/Prototypes/EntProtoId.cs

@@ -1,4 +1,6 @@
-using Robust.Shared.Serialization.TypeSerializers.Implementations;
+using System;
+using Robust.Shared.Serialization;
+using Robust.Shared.Serialization.TypeSerializers.Implementations;
 
 namespace Robust.Shared.Prototypes;
 
@@ -10,7 +12,8 @@ namespace Robust.Shared.Prototypes;
 ///     This will be automatically validated by <see cref="EntProtoIdSerializer"/> if used in data fields.
 /// </remarks>
 /// <remarks><seealso cref="ProtoId{T}"/> for a wrapper of other prototype kinds.</remarks>
-public readonly record struct EntProtoId(string Id)
+[Serializable, NetSerializable]
+public readonly record struct EntProtoId(string Id) : IEquatable<string>, IComparable<EntProtoId>
 {
     public static implicit operator string(EntProtoId protoId)
     {
@@ -21,4 +24,19 @@ public readonly record struct EntProtoId(string Id)
     {
         return new EntProtoId(id);
     }
+
+    public static implicit operator EntProtoId?(string? id)
+    {
+        return id == null ? default(EntProtoId?) : new EntProtoId(id);
+    }
+
+    public bool Equals(string? other)
+    {
+        return Id == other;
+    }
+
+    public int CompareTo(EntProtoId other)
+    {
+        return string.Compare(Id, other.Id, StringComparison.Ordinal);
+    }
 }

Robust.Shared/Prototypes/EntityCategoryPrototype.cs

@@ -0,0 +1,25 @@
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Robust.Shared.Prototypes;
+
+/// <summary>
+/// Prototype that represents game entities.
+/// </summary>
+[Prototype("entityCategory")]
+public sealed class EntityCategoryPrototype : IPrototype
+{
+    [IdDataField]
+    public string ID { get; private set; } = default!;
+
+    /// <summary>
+    /// Localized name of the category, for use in entity spawn menus.
+    /// </summary>
+    [DataField("name")]
+    public string? Name { get; private set; }
+
+    /// <summary>
+    /// Localized description of the category, for use in entity spawn menus.
+    /// </summary>
+    [DataField("description")]
+    public string? Description { get; private set; }
+}

Robust.Shared/Prototypes/EntityPrototype.cs

@@ -4,7 +4,6 @@ using System.Diagnostics.CodeAnalysis;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
-using Robust.Shared.Log;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 using Robust.Shared.Serialization;
@@ -12,6 +11,7 @@ using Robust.Shared.Serialization.Manager;
 using Robust.Shared.Serialization.Manager.Attributes;
 using Robust.Shared.Serialization.Markdown.Mapping;
 using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype.Array;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype.Set;
 using Robust.Shared.ViewVariables;
 
 namespace Robust.Shared.Prototypes
@@ -27,6 +27,9 @@ namespace Robust.Shared.Prototypes
 
         private static readonly Dictionary<string, string> LocPropertiesDefault = new();
 
+        [ValidatePrototypeId<EntityCategoryPrototype>]
+        private const string HideCategory = "hideSpawnMenu";
+
         // LOCALIZATION NOTE:
         // Localization-related properties in here are manually localized in LocalizationManager.
         // As such, they should NOT be inherited to avoid confusing the system.
@@ -57,6 +60,10 @@ namespace Robust.Shared.Prototypes
         [DataField("suffix")]
         public string? SetSuffix { get; private set; }
 
+        [DataField("categories")]
+        [AlwaysPushInheritance]
+        public HashSet<string> Categories = new();
+
         [ViewVariables]
         public IReadOnlyDictionary<string, string> LocProperties => _locPropertiesSet ?? LocPropertiesDefault;
 
@@ -92,8 +99,11 @@ namespace Robust.Shared.Prototypes
         [ViewVariables]
         [NeverPushInheritance]
         [DataField("noSpawn")]
+        [Obsolete("Use the HideSpawnMenu")]
         public bool NoSpawn { get; private set; }
 
+        public bool HideSpawnMenu => Categories.Contains(HideCategory) || NoSpawn;
+
         [DataField("placement")]
         private EntityPlacementProperties PlacementProperties = new();
 

Robust.Shared/Prototypes/ProtoId.cs

@@ -1,4 +1,5 @@
-using Robust.Shared.Serialization.TypeSerializers.Implementations.Generic;
+using System;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Generic;
 
 namespace Robust.Shared.Prototypes;
 
@@ -11,7 +12,8 @@ namespace Robust.Shared.Prototypes;
 ///     This will be automatically validated by <see cref="ProtoIdSerializer{T}"/> if used in data fields.
 /// </remarks>
 /// <remarks><seealso cref="EntProtoId"/> for an <see cref="EntityPrototype"/> alias.</remarks>
-public readonly record struct ProtoId<T>(string Id) where T : class, IPrototype
+[Serializable]
+public readonly record struct ProtoId<T>(string Id) : IEquatable<string>, IComparable<ProtoId<T>> where T : class, IPrototype
 {
     public static implicit operator string(ProtoId<T> protoId)
     {
@@ -22,4 +24,19 @@ public readonly record struct ProtoId<T>(string Id) where T : class, IPrototype
     {
         return new ProtoId<T>(id);
     }
+
+    public static implicit operator ProtoId<T>?(string? id)
+    {
+        return id == null ? default(ProtoId<T>?) : new ProtoId<T>(id);
+    }
+
+    public bool Equals(string? other)
+    {
+        return Id == other;
+    }
+
+    public int CompareTo(ProtoId<T> other)
+    {
+        return string.Compare(Id, other.Id, StringComparison.Ordinal);
+    }
 }

Robust.Shared/Robust.Shared.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="Linguini.Bundle" Version="0.1.3" />
     <PackageReference Include="SharpZstd.Interop" Version="1.5.2-beta2" PrivateAssets="compile" />
     <PackageReference Include="SpaceWizards.Sodium" Version="0.2.1" PrivateAssets="compile" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.7" />
     <PackageReference Include="TerraFX.Interop.Windows" Version="10.0.20348-rc2" PrivateAssets="compile" />
   </ItemGroup>
   <ItemGroup>

Robust.Shared/Serialization/Manager/SerializationManager.Composition.cs

@@ -112,14 +112,40 @@ public partial class SerializationManager
         }, (node, this));
     }
 
-    private SequenceDataNode PushInheritanceSequence(SequenceDataNode child, SequenceDataNode _)
+    private SequenceDataNode PushInheritanceSequence(SequenceDataNode child, SequenceDataNode parent)
     {
-        return child; //todo implement different inheritancebehaviours for yamlfield
+        //todo implement different inheritancebehaviours for yamlfield
+        // I have NFI what this comment means.
+
+        var result = new SequenceDataNode(child.Count + parent.Count);
+        foreach (var entry in parent)
+        {
+            result.Add(entry);
+        }
+        foreach (var entry in child)
+        {
+            result.Add(entry);
+        }
+
+        return result;
     }
 
-    private MappingDataNode PushInheritanceMapping(MappingDataNode child, MappingDataNode _)
+    private MappingDataNode PushInheritanceMapping(MappingDataNode child, MappingDataNode parent)
     {
-        return child; //todo implement different inheritancebehaviours for yamlfield
+        //todo implement different inheritancebehaviours for yamlfield
+        // I have NFI what this comment means.
+
+        var result = new MappingDataNode(child.Count + parent.Count);
+        foreach (var (k, v) in parent)
+        {
+            result[k] = v;
+        }
+        foreach (var (k, v) in child)
+        {
+            result[k] = v;
+        }
+
+        return result;
     }
 
     private MappingDataNode PushInheritanceDefinition(MappingDataNode child, MappingDataNode parent,

Robust.Shared/Serialization/TypeSerializers/Implementations/LocIdSerializer.cs

@@ -0,0 +1,42 @@
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Robust.Shared.Serialization.Manager;
+using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.Serialization.Markdown;
+using Robust.Shared.Serialization.Markdown.Validation;
+using Robust.Shared.Serialization.Markdown.Value;
+using Robust.Shared.Serialization.TypeSerializers.Interfaces;
+using static Robust.Shared.Serialization.Manager.ISerializationManager;
+
+namespace Robust.Shared.Serialization.TypeSerializers.Implementations;
+
+/// <summary>
+///     Serializer used automatically for <see cref="LocId"/> types.
+/// </summary>
+[TypeSerializer]
+public sealed class LocIdSerializer : ITypeSerializer<LocId, ValueDataNode>, ITypeCopyCreator<LocId>
+{
+    public ValidationNode Validate(ISerializationManager serializationManager, ValueDataNode node, IDependencyCollection dependencies, ISerializationContext? context = null)
+    {
+        var loc = dependencies.Resolve<ILocalizationManager>();
+        if (loc.HasString(node.Value))
+            return new ValidatedValueNode(node);
+
+        return new ErrorNode(node, $"No localization message found with id {node.Value}");
+    }
+
+    public LocId Read(ISerializationManager serializationManager, ValueDataNode node, IDependencyCollection dependencies, SerializationHookContext hookCtx, ISerializationContext? context = null, InstantiationDelegate<LocId>? instanceProvider = null)
+    {
+        return new LocId(node.Value);
+    }
+
+    public DataNode Write(ISerializationManager serializationManager, LocId value, IDependencyCollection dependencies, bool alwaysWrite = false, ISerializationContext? context = null)
+    {
+        return new ValueDataNode(value);
+    }
+
+    public LocId CreateCopy(ISerializationManager serializationManager, LocId source, IDependencyCollection dependencies, SerializationHookContext hookCtx, ISerializationContext? context = null)
+    {
+        return source;
+    }
+}

Robust.Shared/Toolshed/TypeParsers/Math/AngleTypeParser.cs

@@ -34,7 +34,7 @@ public sealed class AngleTypeParser : TypeParser<Angle>
 
         if (word.EndsWith("deg"))
         {
-            if (!float.TryParse(word[..^3], out var f))
+            if (!float.TryParse(word[..^3], CultureInfo.InvariantCulture, out var f))
             {
                 error = new InvalidAngle(word);
                 result = null;
@@ -47,7 +47,7 @@ public sealed class AngleTypeParser : TypeParser<Angle>
         }
         else
         {
-            if (!float.TryParse(word, out var f))
+            if (!float.TryParse(word, CultureInfo.InvariantCulture, out var f))
             {
                 error = new InvalidAngle(word);
                 result = null;

Robust.Shared/Utility/DebugTools.cs

@@ -1,8 +1,10 @@
 using System;
+using System.Data;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
 
 namespace Robust.Shared.Utility
 {
@@ -36,6 +38,67 @@ namespace Robust.Shared.Utility
                 throw new DebugAssertException();
         }
 
+        [Conditional("DEBUG")]
+        [AssertionMethod]
+        public static void AssertEqual(object? objA, object? objB)
+        {
+            if (ReferenceEquals(objA, objB))
+                return;
+
+            if (objA == null || !objA.Equals(objB))
+                throw new DebugAssertException($"Expected: {objB ?? "null"} but was {objA ?? "null"}");
+        }
+
+        [Conditional("DEBUG")]
+        [AssertionMethod]
+        public static void AssertEqual(object? objA, object? objB, string message)
+        {
+            if (ReferenceEquals(objA, objB))
+                return;
+
+            if (objA == null || !objA.Equals(objB))
+                throw new DebugAssertException($"{message}\nExpected: {objB ?? "null"} but was {objA ?? "null"}");
+        }
+
+        [Conditional("DEBUG")]
+        [AssertionMethod]
+        public static void AssertNotEqual(object? objA, object? objB)
+        {
+            if (ReferenceEquals(objA, objB))
+                throw new DebugAssertException($"Expected: not {objB ?? "null"}");
+
+            if (objA == null || !objA.Equals(objB))
+                return;
+
+            throw new DebugAssertException($"Expected: not {objB}");
+        }
+
+        [Conditional("DEBUG")]
+        [AssertionMethod]
+        public static void AssertNotEqual(object? objA, object? objB, string message)
+        {
+            if (ReferenceEquals(objA, objB))
+                throw new DebugAssertException($"{message}\nExpected: not {objB ?? "null"}");
+
+            if (objA == null || !objA.Equals(objB))
+                return;
+
+            throw new DebugAssertException($"{message}\nExpected: not {objB}");
+        }
+
+        [Conditional("DEBUG")]
+        [AssertionMethod]
+        public static void AssertOwner(EntityUid? uid, IComponent component)
+        {
+            if (uid == null)
+                throw new DebugAssertException($"Null entity uid cannot own a component. Component: {component.GetType().Name}");
+
+            // Whenever .owner is removed this will need to be replaced by something.
+            // We need some way to ensure that people don't mix up uids & components when calling methods.
+            if (component.Owner != uid)
+                throw new DebugAssertException($"Entity {uid} is not the owner of the component. Component: {component.GetType().Name}");
+        }
+
         /// <summary>
         ///     An assertion that will <see langword="throw" /> an exception if the
         ///     <paramref name="condition" /> is not true.

Robust.Shared/Utility/UniqueIndexHkm.cs

@@ -43,14 +43,7 @@ namespace Robust.Shared.Utility
         public bool Add(TKey key, TValue value)
         {
             InitializedCheck();
-
-            if (_index.TryGetValue(key, out var set))
-            {
-                return set.Add(value);
-            }
-
-            _index.Add(key, new HashSet<TValue> {value});
-            return true;
+            return _index.GetOrNew(key).Add(value);
         }
 
         /// <inheritdoc />

Robust.UnitTesting/Server/RobustServerSimulation.cs

@@ -223,13 +223,14 @@ namespace Robust.UnitTesting.Server
             container.RegisterInstance<IConsoleHost>(new Mock<IConsoleHost>().Object); //Console is technically a frontend, we want to run headless
             container.Register<IEntityManager, EntityManager>();
             container.Register<EntityManager, EntityManager>();
-            container.Register<IMapManager, MapManager>();
+            container.Register<IMapManager, NetworkedMapManager>();
+            container.Register<INetworkedMapManager, NetworkedMapManager>();
+            container.Register<IMapManagerInternal, NetworkedMapManager>();
             container.Register<ISerializationManager, SerializationManager>();
             container.Register<IPrototypeManager, ServerPrototypeManager>();
             container.Register<IComponentFactory, ComponentFactory>();
             container.Register<IEntitySystemManager, EntitySystemManager>();
             container.Register<IManifoldManager, CollisionManager>();
-            container.Register<IMapManagerInternal, MapManager>();
             container.Register<INetManager, NetManager>();
             container.Register<IAuthManager, AuthManager>();
             container.Register<ITileDefinitionManager, TileDefinitionManager>();

Robust.UnitTesting/Shared/GameState/VisibilityTest.cs

@@ -0,0 +1,131 @@
+using System.Linq;
+using System.Numerics;
+using System.Threading.Tasks;
+using NUnit.Framework;
+using Robust.Server.GameObjects;
+using Robust.Server.Player;
+using Robust.Shared;
+using Robust.Shared.GameObjects;
+using Robust.Shared.GameStates;
+using Robust.Shared.IoC;
+using Robust.Shared.Map;
+using Robust.Shared.Network;
+
+namespace Robust.UnitTesting.Shared.GameState;
+
+public sealed partial class VisibilityTest : RobustIntegrationTest
+{
+    /// <summary>
+    /// This tests checks that entity visibility masks are recursively applied to children.
+    /// </summary>
+    [Test]
+    public async Task UnknownEntityTest()
+    {
+        var server = StartServer();
+
+        var xforms = server.System<SharedTransformSystem>();
+        var vis = server.System<VisibilitySystem>();
+
+        const int RequiredMask = 1;
+        // All entities need to have this mask set ... which defeat the whole point of that bit?
+
+        // Spawn a stack of entities
+        int N = 6;
+        var ents = new EntityUid[N];
+        var metaComp = new MetaDataComponent[N];
+        var visComp = new VisibilityComponent[N];
+        await server.WaitPost(() =>
+        {
+            for (int i = 0; i < N; i++)
+            {
+                var ent = server.EntMan.Spawn();
+
+                ents[i] = ent;
+                metaComp[i] = server.EntMan.GetComponent<MetaDataComponent>(ent);
+                visComp[i] = server.EntMan.AddComponent<VisibilityComponent>(ent);
+
+                vis.AddLayer(ent, visComp[i], 1 << i);
+                if (i > 0)
+                    xforms.SetParent(ent, ents[i - 1]);
+            }
+        });
+
+        // Each entity's visibility mask should include the parent's mask
+        var mask = RequiredMask;
+        for (int i = 0; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        // Adding a layer to the root entity's mask will apply it to all children
+        var extraMask = 1 << (N + 1);
+        mask = RequiredMask | extraMask;
+        vis.AddLayer(ents[0], visComp[0], extraMask);
+        for (int i = 0; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        // Removing the removes it from all children.
+        vis.RemoveLayer(ents[0], visComp[0], extraMask);
+        mask = RequiredMask;
+        for (int i = 0; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        // Detaching an entity from the stack updates it, and it's children's mask
+        var split = N / 2;
+        await server.WaitPost(() => xforms.SetParent(ents[split], EntityUid.Invalid));
+
+        mask = RequiredMask;
+        for (int i = 0; i < split; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        mask = RequiredMask;
+        for (int i = split; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        // Re-attaching the entity also updates the masks.
+        await server.WaitPost(() => xforms.SetParent(ents[split], ents[split-1]));
+        mask = RequiredMask;
+        for (int i = 0; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        // Setting a mask on a child does not propagate upwards, only downwards
+        vis.AddLayer(ents[split], visComp[split], extraMask);
+        mask = RequiredMask;
+        for (int i = 0; i < split; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+
+        mask |= extraMask;
+        for (int i = split; i < N; i++)
+        {
+            mask |= 1 << i;
+            var meta = metaComp[i];
+            Assert.That(meta.VisibilityMask, Is.EqualTo(mask));
+        }
+    }
+}