Fix RCD not being able to place hull tiles in space (#42740)

Fall back on player's grid if RCD is clicked on empty space

Content.Shared/RCD/Systems/RCDSystem.cs

@@ -145,7 +145,13 @@ public sealed class RCDSystem : EntitySystem
         if (!location.IsValid(EntityManager))
             return;
 
-        var gridUid = _transform.GetGrid(location);
+        // Get grid corresponding to user's click location.
+        // If that doesn't exist, try using the one they're standing on.
+        // In the future we might want to also check adjacent spaces for grids,
+        // in case the user is floating in space for whatever reason.
+        var clickGridUid = _transform.GetGrid(location);
+        var userGridUid = _transform.GetGrid(user);
+        var gridUid = clickGridUid.HasValue ? clickGridUid : userGridUid;
 
         if (!TryComp<MapGridComponent>(gridUid, out var mapGrid))
         {
@@ -217,9 +223,14 @@ public sealed class RCDSystem : EntitySystem
         #endregion
 
         // Try to start the do after
-        var effect = Spawn(effectPrototype, location);
-        var ev = new RCDDoAfterEvent(GetNetCoordinates(location), component.ConstructionDirection, component.ProtoId, cost, GetNetEntity(effect));
-
+        var effect = Spawn(effectPrototype, _mapSystem.ToCenterCoordinates(tile, mapGrid));
+        var ev = new RCDDoAfterEvent(
+            GetNetCoordinates(location),
+            GetNetEntity(gridUid.Value),
+            component.ConstructionDirection,
+            component.ProtoId,
+            cost,
+            GetNetEntity(effect));
         var doAfterArgs = new DoAfterArgs(EntityManager, user, delay, ev, uid, target: args.Target, used: uid)
         {
             BreakOnDamage = true,
@@ -249,9 +260,7 @@ public sealed class RCDSystem : EntitySystem
         }
 
         // Ensure the RCD operation is still valid
-        var location = GetCoordinates(args.Event.Location);
-
-        var gridUid = _transform.GetGrid(location);
+        var gridUid = GetEntity(args.Event.TargetGridId);
 
         if (!TryComp<MapGridComponent>(gridUid, out var mapGrid))
         {
@@ -259,11 +268,11 @@ public sealed class RCDSystem : EntitySystem
             return;
         }
 
+        var location = GetCoordinates(args.Event.Location);
+        var tile = _mapSystem.GetTileRef(gridUid, mapGrid, location);
+        var position = _mapSystem.TileIndicesFor(gridUid, mapGrid, location);
 
-        var tile = _mapSystem.GetTileRef(gridUid.Value, mapGrid, location);
-        var position = _mapSystem.TileIndicesFor(gridUid.Value, mapGrid, location);
-
-        if (!IsRCDOperationStillValid(uid, component, gridUid.Value, mapGrid, tile, position, args.Event.Direction, args.Event.Target, args.Event.User))
+        if (!IsRCDOperationStillValid(uid, component, gridUid, mapGrid, tile, position, args.Event.Direction, args.Event.Target, args.Event.User))
             args.Cancel();
     }
 
@@ -282,22 +291,23 @@ public sealed class RCDSystem : EntitySystem
 
         args.Handled = true;
 
-        var location = GetCoordinates(args.Location);
-
-        var gridUid = _transform.GetGrid(location);
+        var gridUid = GetEntity(args.TargetGridId);
 
         if (!TryComp<MapGridComponent>(gridUid, out var mapGrid))
             return;
 
-        var tile = _mapSystem.GetTileRef(gridUid.Value, mapGrid, location);
-        var position = _mapSystem.TileIndicesFor(gridUid.Value, mapGrid, location);
+        var location = GetCoordinates(args.Location);
+        var tile = _mapSystem.GetTileRef(gridUid, mapGrid, location);
+        var position = _mapSystem.TileIndicesFor(gridUid, mapGrid, location);
 
         // Ensure the RCD operation is still valid
-        if (!IsRCDOperationStillValid(uid, component, gridUid.Value, mapGrid, tile, position, args.Direction, args.Target, args.User))
+        if (!IsRCDOperationStillValid(uid, component, gridUid, mapGrid, tile, position, args.Direction, args.Target, args.User))
+        {
             return;
+        }
 
         // Finalize the operation (this should handle prediction properly)
-        FinalizeRCDOperation(uid, component, gridUid.Value, mapGrid, tile, position, args.Direction, args.Target, args.User);
+        FinalizeRCDOperation(uid, component, gridUid, mapGrid, tile, position, args.Direction, args.Target, args.User);
 
         // Play audio and consume charges
         _audio.PlayPredicted(component.SuccessSound, uid, args.User);
@@ -652,6 +662,9 @@ public sealed partial class RCDDoAfterEvent : DoAfterEvent
     [DataField(required: true)]
     public NetCoordinates Location { get; private set; }
 
+    [DataField(required: true)]
+    public NetEntity TargetGridId {get ; private set; }
+
     [DataField]
     public Direction Direction { get; private set; }
 
@@ -666,9 +679,17 @@ public sealed partial class RCDDoAfterEvent : DoAfterEvent
 
     private RCDDoAfterEvent() { }
 
-    public RCDDoAfterEvent(NetCoordinates location, Direction direction, ProtoId<RCDPrototype> startingProtoId, int cost, NetEntity? effect = null)
+    public RCDDoAfterEvent(
+        NetCoordinates location,
+        NetEntity targetGridId,
+        Direction direction,
+        ProtoId<RCDPrototype>
+        startingProtoId,
+        int cost,
+        NetEntity? effect = null)
     {
         Location = location;
+        TargetGridId = targetGridId;
         Direction = direction;
         StartingProtoId = startingProtoId;
         Cost = cost;

Resources/Prototypes/Tiles/plating.yml

@@ -22,6 +22,7 @@
   parent: Plating
   name: tiles-rcd-plating
   baseWhitelist:
+    - Space
     - TrainLattice
     - FloorPlanetDirt
     - FloorDesert