Sloth's subfloor vismask adventure (#35347)

* Add a subfloor vismask

Significantly cuts down on sent entity count.

* More optimisations

* Fix command

* Fixes

* namespace cleanup

* Review

* Vismasks

* Content update

* Bandaid

* awewa

* Revert these

* reh

* Update Content.Shared/SubFloor/TrayScannerComponent.cs

---------

Co-authored-by: slarticodefast <161409025+slarticodefast@users.noreply.github.com>

Content.Server/SubFloor/SubFloorHideSystem.cs

@@ -1,16 +1,76 @@
 using Content.Shared.Construction.Components;
+using Content.Shared.Eye;
 using Content.Shared.SubFloor;
+using Robust.Server.Player;
+using Robust.Shared.Enums;
 using Robust.Shared.Map.Components;
+using Robust.Shared.Player;
 
 namespace Content.Server.SubFloor;
 
 public sealed class SubFloorHideSystem : SharedSubFloorHideSystem
 {
+    [Dependency] private readonly IPlayerManager _player = default!;
+    [Dependency] private readonly SharedEyeSystem _eye = default!;
+
+    private HashSet<ICommonSession> _showFloors = new();
+
     public override void Initialize()
     {
         base.Initialize();
         SubscribeLocalEvent<SubFloorHideComponent, AnchorAttemptEvent>(OnAnchorAttempt);
         SubscribeLocalEvent<SubFloorHideComponent, UnanchorAttemptEvent>(OnUnanchorAttempt);
+        SubscribeNetworkEvent<ShowSubfloorRequestEvent>(OnShowSubfloor);
+        SubscribeLocalEvent<GetVisMaskEvent>(OnGetVisibility);
+
+        _player.PlayerStatusChanged += OnPlayerStatus;
+    }
+
+    private void OnPlayerStatus(object? sender, SessionStatusEventArgs e)
+    {
+        if (e.NewStatus == SessionStatus.Connected)
+            return;
+
+        _showFloors.Remove(e.Session);
+
+        if (e.Session.AttachedEntity != null)
+            _eye.RefreshVisibilityMask(e.Session.AttachedEntity.Value);
+    }
+
+    private void OnGetVisibility(ref GetVisMaskEvent ev)
+    {
+        if (!TryComp(ev.Entity, out ActorComponent? actor))
+            return;
+
+        if (_showFloors.Contains(actor.PlayerSession))
+        {
+            ev.VisibilityMask |= (int)VisibilityFlags.Subfloor;
+        }
+    }
+
+    private void OnShowSubfloor(ShowSubfloorRequestEvent ev, EntitySessionEventArgs args)
+    {
+        // TODO: Commands are a bit of an eh? for client-only but checking shared perms
+        var ent = args.SenderSession.AttachedEntity;
+
+        if (!TryComp(ent, out EyeComponent? eyeComp))
+            return;
+
+        if (ev.Value)
+        {
+            _showFloors.Add(args.SenderSession);
+        }
+        else
+        {
+            _showFloors.Remove(args.SenderSession);
+        }
+
+        _eye.RefreshVisibilityMask((ent.Value, eyeComp));
+
+        RaiseNetworkEvent(new ShowSubfloorRequestEvent()
+        {
+            Value = ev.Value,
+        }, args.SenderSession);
     }
 
     private void OnAnchorAttempt(EntityUid uid, SubFloorHideComponent component, AnchorAttemptEvent args)