Add some more coordinate utility functions.

OpenRA.Game/Map/CellLayer.cs

@@ -125,10 +125,25 @@ namespace OpenRA
 			return GetEnumerator();
 		}
 
+		public bool Contains(CPos cell)
+		{
+			return Contains(cell.ToMPos(Shape));
+		}
+
 		public bool Contains(MPos uv)
 		{
 			return bounds.Contains(uv.U, uv.V);
 		}
+
+		public CPos Clamp(CPos uv)
+		{
+			return Clamp(uv.ToMPos(Shape)).ToCPos(Shape);
+		}
+
+		public MPos Clamp(MPos uv)
+		{
+			return uv.Clamp(new Rectangle(0, 0, Size.Width - 1, Size.Height - 1));
+		}
 	}
 
 	// Helper functions

OpenRA.Game/Map/CellRegion.cs

@@ -217,6 +217,9 @@ namespace OpenRA
 			{
 				return GetEnumerator();
 			}
+
+			public MPos TopLeft { get { return r.mapTopLeft; } }
+			public MPos BottomRight { get { return r.mapBottomRight; } }
 		}
 	}
 }

OpenRA.Game/Map/Map.cs

@@ -772,6 +772,12 @@ namespace OpenRA
 			return cell.ToMPos(this).Clamp(bounds).ToCPos(this);
 		}
 
+		public MPos Clamp(MPos uv)
+		{
+			var bounds = new Rectangle(Bounds.X, Bounds.Y, Bounds.Width - 1, Bounds.Height - 1);
+			return uv.Clamp(bounds);
+		}
+
 		public CPos ChooseRandomCell(MersenneTwister rand)
 		{
 			var x = rand.Next(Bounds.Left, Bounds.Right);