diff --git a/OpenRa.Game/Sidebar.cs b/OpenRa.Game/Sidebar.cs
index 8dbe2fbb80..e10a6b50b5 100644
--- a/OpenRa.Game/Sidebar.cs
+++ b/OpenRa.Game/Sidebar.cs
@@ -52,16 +52,16 @@ namespace OpenRa.Game
 			p.Y += 48;
 		}
 
-		void Fill(Size clientSize, float2 p)
+		void Fill(float height, float2 p)
 		{
-			while (p.Y < clientSize.Height)
+			while (p.Y < height)
 				DrawSprite(blank, ref p);
 		}
 
 		public void Paint()
 		{
-			float2 buildPos = viewport.Location + new float2(viewport.ClientSize.Width - 128, 0);
-			float2 unitPos = viewport.Location + new float2(viewport.ClientSize.Width - 64, 0);
+			float2 buildPos = viewport.Location + new float2(viewport.Size.X - 128, 0);
+			float2 unitPos = viewport.Location + new float2(viewport.Size.X - 64, 0);
 			
 			foreach (Item i in techTree.BuildableItems)
 			{
@@ -74,8 +74,8 @@ namespace OpenRa.Game
 					DrawSprite( sprite, ref unitPos );
 			}
 
-			Fill(viewport.ClientSize, buildPos);
-			Fill(viewport.ClientSize, unitPos);
+			Fill(viewport.Size.Y, buildPos);
+			Fill(viewport.Size.Y, unitPos);
 
 			spriteRenderer.Flush();
 		}
diff --git a/OpenRa.Game/TerrainRenderer.cs b/OpenRa.Game/TerrainRenderer.cs
index 3a50a7d280..d18946bf5a 100644
--- a/OpenRa.Game/TerrainRenderer.cs
+++ b/OpenRa.Game/TerrainRenderer.cs
@@ -63,9 +63,9 @@ namespace OpenRa.Game
 			int indicesPerRow = map.Width * 6;
 			int verticesPerRow = map.Width * 4;
 
-			int visibleRows = (int)(viewport.ClientSize.Height / 24.0f + 2);
+			int visibleRows = (int)(viewport.Size.Y / 24.0f + 2);
 
-			int firstRow = (int)(viewport.ScrollPosition.Y / 24.0f);
+			int firstRow = (int)(viewport.Location.Y / 24.0f);
 			int lastRow = firstRow + visibleRows;
 
 			if (lastRow < 0 || firstRow > map.Height)
diff --git a/OpenRa.Game/Viewport.cs b/OpenRa.Game/Viewport.cs
index 32f8380f07..3b0730cc79 100644
--- a/OpenRa.Game/Viewport.cs
+++ b/OpenRa.Game/Viewport.cs
@@ -14,15 +14,15 @@ namespace OpenRa.Game
 		float2 scrollPosition;
 		readonly Renderer renderer;
 
-		public PointF ScrollPosition { get { return scrollPosition.ToPointF(); } }
 		public Size ClientSize { get { return clientSize; } }
 
 		public float2 Location { get { return scrollPosition; } }
-		public float2 Size { get { return scrollPosition + new float2(ClientSize); } }
+		public float2 Size { get { return new float2(ClientSize); } }
 
 		public void Scroll(float2 delta)
 		{
-			scrollPosition = (scrollPosition + delta).Constrain(new Range<float2>(float2.Zero, mapSize));
+			scrollPosition = (scrollPosition + delta).Constrain(
+				new Range<float2>(float2.Zero, mapSize));
 		}
 
 		public Viewport(Size clientSize, float2 mapSize, Renderer renderer)
@@ -56,7 +56,7 @@ namespace OpenRa.Game
 
 		public void DrawRegions()
 		{
-			float2 r1 = new float2(2.0f / clientSize.Width, -2.0f / clientSize.Height);
+			float2 r1 = new float2(2, -2) / Size;
 			float2 r2 = new float2(-1, 1);
 			
 			renderer.BeginFrame(r1, r2, scrollPosition);