fix FaceSpaceCenter requirement

Assets/Engine/Runtime/Placement.cs

@@ -30,24 +30,48 @@ namespace EscapeRoomEngine.Engine.Runtime
                 };
             }
         }
+
+        /// <summary>
+        /// Get the geometric center of this placement taking into account its orientation.
+        /// </summary>
+        public Vector3 GeometricCenter
+        {
+            get
+            {
+                var sizeMinusOne = size - Vector2Int.one;
+                var half = new Vector2(sizeMinusOne.x/2f, sizeMinusOne.y/2f);
+                var horizontal = new Vector3(half.x, 0, half.y);
+                var vertical = new Vector3(half.y, 0, -half.x);
+                var geometricPosition = position + new Vector3(0.5f, 0, 0.5f);
+#pragma warning disable CS8524
+                return orientation switch
+#pragma warning restore CS8524
+                {
+                    Orientation.North => geometricPosition + horizontal,
+                    Orientation.East => geometricPosition + vertical,
+                    Orientation.South => geometricPosition - horizontal,
+                    Orientation.West => geometricPosition - vertical
+                };
+            }
+        }
         
         /// <summary>
-        /// Get the positions of the two back corners. The first one is just the position of the placement.
+        /// Get the integer positions of the two back corners. The first one is just the position of the placement.
         /// </summary>
-        /// <exception cref="ArgumentOutOfRangeException"></exception>
         public (Vector3Int, Vector3Int) BackCorners {
             get
             {
                 var width = size.x - 1;
                 var horizontal = new Vector3Int(width, 0, 0);
                 var vertical = new Vector3Int(0, 0, width);
+#pragma warning disable CS8524
                 var otherCorner = orientation switch
+#pragma warning restore CS8524
                 {
                     Orientation.North => position + horizontal,
                     Orientation.East => position - vertical,
                     Orientation.South => position - horizontal,
-                    Orientation.West => position + vertical,
-                    _ => throw new ArgumentOutOfRangeException()
+                    Orientation.West => position + vertical
                 };
                 return (position, otherCorner);
             }