Add draw depth constants to content

Content.Shared/GameObjects/DrawDepth.cs

@@ -0,0 +1,27 @@
+using DrawDepthTag = Robust.Shared.GameObjects.DrawDepth;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects
+{
+    [ConstantsFor(typeof(DrawDepthTag))]
+    public enum DrawDepth
+    {
+        LowFloors = DrawDepthTag.Default - 7,
+        /// <summary>
+        /// Things that are beneath regular floors, such as wires.
+        /// </summary>
+        BelowFloor = DrawDepthTag.Default - 6,
+        FloorTiles = DrawDepthTag.Default - 5,
+        /// <summary>
+        /// Things that are actually right on the floor, like vents.
+        /// </summary>
+        FloorObjects = DrawDepthTag.Default - 4,
+        Walls = DrawDepthTag.Default - 3,
+        WallTops = DrawDepthTag.Default - 2,
+        WallMountedItems = DrawDepthTag.Default - 1,
+        Objects = DrawDepthTag.Default,
+        Items = DrawDepthTag.Default + 1,
+        Mobs = DrawDepthTag.Default + 2,
+        Overlays = DrawDepthTag.Default + 3,
+    }
+}