Allow t-ray to penetrate carpets and puddles

Content.Client/SubFloor/SubFloorHideSystem.cs

@@ -1,3 +1,4 @@
+using Content.Shared.DrawDepth;
 using Content.Shared.SubFloor;
 using Robust.Client.GameObjects;
 
@@ -62,6 +63,18 @@ private void OnAppearanceChanged(EntityUid uid, SubFloorHideComponent component,
         }
 
         args.Sprite.Visible = hasVisibleLayer || revealed;
+
+        // allows a t-ray to show wires/pipes above carpets/puddles
+        if (scannerRevealed)
+        {
+            component.OriginalDrawDepth ??= args.Sprite.DrawDepth;
+            args.Sprite.DrawDepth = (int) Shared.DrawDepth.DrawDepth.FloorObjects + 1;
+        }
+        else if (component.OriginalDrawDepth.HasValue)
+        {
+            args.Sprite.DrawDepth = component.OriginalDrawDepth.Value;
+            component.OriginalDrawDepth = null;
+        }
     }
 
     private void UpdateAll()

Content.Shared/SubFloor/SubFloorHideComponent.cs

@@ -45,5 +45,12 @@ public sealed partial class SubFloorHideComponent : Component
         /// </summary>
         [DataField("visibleLayers")]
         public HashSet<Enum> VisibleLayers = new() { SubfloorLayers.FirstLayer };
+
+        /// <summary>
+        /// This is used for storing the original draw depth of a t-ray revealed entity.
+        /// e.g. when a t-ray revealed cable is drawn above a carpet.
+        /// </summary>
+        [DataField]
+        public int? OriginalDrawDepth;
     }
 }