Add layer support check, add enum for room layer location/type

NHSE.Core/Structures/Map/Managers/RoomItemManager.cs

@@ -1,31 +1,56 @@
-using System.Diagnostics;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
 
 namespace NHSE.Core
 {
     public class RoomItemManager
     {
-        // Layer 1: Base Layer Placed Items
-        // Layer 2: Supported Layer Placed Items
-        // Layer 3: North Wall
-        // Layer 4: ???
-        // Layer 5: ???
-        // Layer 6: ???
-        // Layer 7: Rug
-        // Layer 8: ???
-
         public readonly RoomItemLayer[] Layers;
 
         public readonly PlayerRoom Room;
+        private const int LayerCount = 8;
 
         public RoomItemManager(PlayerRoom room)
         {
             Layers = room.GetItemLayers();
             Room = room;
-            Debug.Assert(Layers.Length == 8);
+            Debug.Assert(Layers.Length == LayerCount);
         }
 
         public void Save() => Room.SetItemLayers(Layers);
 
-        // public bool IsOccupied(int x, int y) => Layers.Any(z => !z.GetTile(x, y).IsNone);
+        public bool IsOccupied(int layer, int x, int y)
+        {
+            if ((uint)layer >= LayerCount)
+                throw new ArgumentOutOfRangeException(nameof(layer));
+
+            var l = Layers[layer];
+            var tile = l.GetTile(x, y);
+            return !tile.IsNone || (layer == 1 && IsOccupied(0, x, y));
+        }
+
+        public List<string> GetUnsupportedTiles()
+        {
+            var lBase = Layers[0];
+            var lSupport = Layers[1];
+            var result = new List<string>();
+            for (int x = 0; x < lBase.MaxWidth; x++)
+            {
+                for (int y = 0; y < lBase.MaxHeight; y++)
+                {
+                    var tile = lSupport.GetTile(x, y);
+                    if (tile.IsNone)
+                        continue;
+
+                    var support = lBase.GetTile(x, y);
+                    if (!support.IsNone)
+                        continue; // dunno how to check if the tile can actually have an item put on top of it...
+
+                    result.Add($"{x:000},{y:000}");
+                }
+            }
+            return result;
+        }
     }
 }

NHSE.Core/Structures/Map/Managers/RoomLayerSurface.cs

@@ -0,0 +1,14 @@
+namespace NHSE.Core
+{
+    public enum RoomLayerSurface
+    {
+        Floor = 0,
+        FloorSupported = 1,
+        WallNorth = 2,
+        WallWest = 3,
+        WallSouth = 4,
+        WallEast = 5,
+        Rugs = 6,
+        Ceiling = 7,
+    }
+}

NHSE.WinForms/Subforms/Map/PlayerHouseEditor.cs

@@ -150,6 +150,9 @@ private void ChangeRoom(PlayerHouse house)
 
         private void ReloadManager(PlayerHouse house)
         {
+            var unsupported = Manager.GetUnsupportedTiles();
+            if (unsupported.Count != 0)
+                WinFormsUtil.Alert(MessageStrings.MsgFieldItemUnsupportedLayer2Tile);
             var room = house.GetRoom(RoomIndex);
             Manager = new RoomItemManager(room);
         }