diff --git a/OpenRA.Game/Primitives/CachedTransform.cs b/OpenRA.Game/Primitives/CachedTransform.cs
new file mode 100644
index 0000000000..a1cf543d76
--- /dev/null
+++ b/OpenRA.Game/Primitives/CachedTransform.cs
@@ -0,0 +1,41 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+
+namespace OpenRA.Primitives
+{
+	public class CachedTransform<T, U>
+	{
+		readonly Func<T, U> transform;
+
+		bool initialized;
+		T lastInput;
+		U lastOutput;
+
+		public CachedTransform(Func<T, U> transform)
+		{
+			this.transform = transform;
+		}
+
+		public U Update(T input)
+		{
+			if (initialized && ((input == null && lastInput == null) || (input != null && input.Equals(lastInput))))
+				return lastOutput;
+
+			lastInput = input;
+			lastOutput = transform(input);
+			initialized = true;
+
+			return lastOutput;
+		}
+	}
+}
diff --git a/OpenRA.Game/Primitives/PredictedCachedTransform.cs b/OpenRA.Game/Primitives/PredictedCachedTransform.cs
new file mode 100644
index 0000000000..dc6217f1e5
--- /dev/null
+++ b/OpenRA.Game/Primitives/PredictedCachedTransform.cs
@@ -0,0 +1,51 @@
+#region Copyright & License Information
+/*
+ * Copyright (c) The OpenRA Developers and Contributors
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version. For more
+ * information, see COPYING.
+ */
+#endregion
+
+using System;
+
+namespace OpenRA.Primitives
+{
+	public class PredictedCachedTransform<T, U>
+	{
+		readonly Func<T, U> transform;
+
+		bool initialized;
+		T lastInput;
+		U lastOutput;
+
+		bool predicted;
+		U prediction;
+
+		public PredictedCachedTransform(Func<T, U> transform)
+		{
+			this.transform = transform;
+		}
+
+		public void Predict(U value)
+		{
+			predicted = true;
+			prediction = value;
+		}
+
+		public U Update(T input)
+		{
+			if ((predicted || initialized) && ((input == null && lastInput == null) || (input != null && input.Equals(lastInput))))
+				return predicted ? prediction : lastOutput;
+
+			predicted = false;
+			initialized = true;
+			lastInput = input;
+			lastOutput = transform(input);
+
+			return lastOutput;
+		}
+	}
+}
diff --git a/OpenRA.Mods.Common/Traits/Render/WithTextControlGroupDecoration.cs b/OpenRA.Mods.Common/Traits/Render/WithTextControlGroupDecoration.cs
index a1255a862b..2f69fe0cdd 100644
--- a/OpenRA.Mods.Common/Traits/Render/WithTextControlGroupDecoration.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithTextControlGroupDecoration.cs
@@ -13,7 +13,6 @@ using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Graphics;
-using OpenRA.Mods.Common.Widgets;
 using OpenRA.Primitives;
 using OpenRA.Traits;
 
diff --git a/OpenRA.Mods.Common/Traits/World/TimeLimitManager.cs b/OpenRA.Mods.Common/Traits/World/TimeLimitManager.cs
index c20a1b61e5..b1331a1a5d 100644
--- a/OpenRA.Mods.Common/Traits/World/TimeLimitManager.cs
+++ b/OpenRA.Mods.Common/Traits/World/TimeLimitManager.cs
@@ -12,6 +12,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Mods.Common.Widgets;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs b/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs
index aa52825639..9af0aad570 100644
--- a/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs
@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Graphics;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets
diff --git a/OpenRA.Mods.Common/Widgets/ImageWidget.cs b/OpenRA.Mods.Common/Widgets/ImageWidget.cs
index 2558081087..425d1a9772 100644
--- a/OpenRA.Mods.Common/Widgets/ImageWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/ImageWidget.cs
@@ -11,6 +11,7 @@
 
 using System;
 using OpenRA.Graphics;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugLogic.cs
index 05ae19001f..d8eaae38ca 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugLogic.cs
@@ -11,6 +11,7 @@
 
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic.Ingame
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugMenuLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugMenuLogic.cs
index 6272561b9b..31ad307893 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugMenuLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/DebugMenuLogic.cs
@@ -11,6 +11,7 @@
 
 using System;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameTimerLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameTimerLogic.cs
index 4f4e00249c..53d7021dbd 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameTimerLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/GameTimerLogic.cs
@@ -12,6 +12,7 @@
 using System;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameCashCounterLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameCashCounterLogic.cs
index daa9003fde..5c97eb05d0 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameCashCounterLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameCashCounterLogic.cs
@@ -12,6 +12,7 @@
 using System;
 using System.Globalization;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs
index 002fe47f56..d714ee4b9a 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs
@@ -15,6 +15,7 @@ using OpenRA.Mods.Common.Commands;
 using OpenRA.Mods.Common.Lint;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Installation/DownloadPackageLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Installation/DownloadPackageLogic.cs
index 20126bb270..54f08d4b6f 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Installation/DownloadPackageLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Installation/DownloadPackageLogic.cs
@@ -16,6 +16,7 @@ using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
 using OpenRA.FileSystem;
+using OpenRA.Primitives;
 using OpenRA.Support;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromSourceLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromSourceLogic.cs
index 943cf5c68a..0c391b9450 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromSourceLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromSourceLogic.cs
@@ -15,6 +15,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using OpenRA.Mods.Common.Installer;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/IntroductionPromptLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/IntroductionPromptLogic.cs
index 5bbc7371cb..7a34ef5f7b 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/IntroductionPromptLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/IntroductionPromptLogic.cs
@@ -12,6 +12,7 @@
 using System;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
index ef94ebf8a7..e4d174ab4e 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyLogic.cs
@@ -15,6 +15,7 @@ using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyOptionsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyOptionsLogic.cs
index 25de1151c5..e674b0186f 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyOptionsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/LobbyOptionsLogic.cs
@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/MapPreviewLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/MapPreviewLogic.cs
index 75b0ca0028..8c2c1c2fb4 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/MapPreviewLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/MapPreviewLogic.cs
@@ -13,6 +13,7 @@ using System;
 using System.Collections.Generic;
 using System.Linq;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Lobby/SpawnSelectorTooltipLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Lobby/SpawnSelectorTooltipLogic.cs
index 771362f7fa..ea8cb2ec23 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Lobby/SpawnSelectorTooltipLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Lobby/SpawnSelectorTooltipLogic.cs
@@ -11,6 +11,7 @@
 
 using System;
 using System.Linq;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
index 2b68c50ab7..23a560d153 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
@@ -12,6 +12,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
index c671663d9e..763199512c 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
@@ -18,6 +18,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using OpenRA.FileFormats;
 using OpenRA.Network;
+using OpenRA.Primitives;
 using OpenRA.Traits;
 using OpenRA.Widgets;
 
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
index ce31770756..4249ebd14d 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Settings/AudioSettingsLogic.cs
@@ -13,6 +13,7 @@ using System;
 using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Settings/DisplaySettingsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Settings/DisplaySettingsLogic.cs
index ade63ee9aa..11989cb828 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Settings/DisplaySettingsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Settings/DisplaySettingsLogic.cs
@@ -16,6 +16,7 @@ using System.Globalization;
 using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Traits;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/Logic/Settings/InputSettingsLogic.cs b/OpenRA.Mods.Common/Widgets/Logic/Settings/InputSettingsLogic.cs
index 9796efa181..b447311f40 100644
--- a/OpenRA.Mods.Common/Widgets/Logic/Settings/InputSettingsLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Settings/InputSettingsLogic.cs
@@ -11,6 +11,7 @@
 
 using System;
 using System.Collections.Generic;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets.Logic
diff --git a/OpenRA.Mods.Common/Widgets/ScrollItemWidget.cs b/OpenRA.Mods.Common/Widgets/ScrollItemWidget.cs
index 965be627e7..bb72373b7b 100644
--- a/OpenRA.Mods.Common/Widgets/ScrollItemWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/ScrollItemWidget.cs
@@ -11,6 +11,7 @@
 
 using System;
 using OpenRA.Graphics;
+using OpenRA.Primitives;
 using OpenRA.Widgets;
 
 namespace OpenRA.Mods.Common.Widgets
diff --git a/OpenRA.Mods.Common/Widgets/WidgetUtils.cs b/OpenRA.Mods.Common/Widgets/WidgetUtils.cs
index 3ceaa541e1..a599d2fbf4 100644
--- a/OpenRA.Mods.Common/Widgets/WidgetUtils.cs
+++ b/OpenRA.Mods.Common/Widgets/WidgetUtils.cs
@@ -396,66 +396,4 @@ namespace OpenRA.Mods.Common.Widgets
 			notificationWidget.Bounds.Width = boxWidth - notificationWidget.Bounds.X;
 		}
 	}
-
-	public class CachedTransform<T, U>
-	{
-		readonly Func<T, U> transform;
-
-		bool initialized;
-		T lastInput;
-		U lastOutput;
-
-		public CachedTransform(Func<T, U> transform)
-		{
-			this.transform = transform;
-		}
-
-		public U Update(T input)
-		{
-			if (initialized && ((input == null && lastInput == null) || (input != null && input.Equals(lastInput))))
-				return lastOutput;
-
-			lastInput = input;
-			lastOutput = transform(input);
-			initialized = true;
-
-			return lastOutput;
-		}
-	}
-
-	public class PredictedCachedTransform<T, U>
-	{
-		readonly Func<T, U> transform;
-
-		bool initialized;
-		T lastInput;
-		U lastOutput;
-
-		bool predicted;
-		U prediction;
-
-		public PredictedCachedTransform(Func<T, U> transform)
-		{
-			this.transform = transform;
-		}
-
-		public void Predict(U value)
-		{
-			predicted = true;
-			prediction = value;
-		}
-
-		public U Update(T input)
-		{
-			if ((predicted || initialized) && ((input == null && lastInput == null) || (input != null && input.Equals(lastInput))))
-				return predicted ? prediction : lastOutput;
-
-			predicted = false;
-			initialized = true;
-			lastInput = input;
-			lastOutput = transform(input);
-
-			return lastOutput;
-		}
-	}
 }
diff --git a/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs b/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
index 939cf44f4e..e0f0d77081 100644
--- a/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
+++ b/OpenRA.Mods.D2k/Traits/Buildings/D2kActorPreviewPlaceBuildingPreview.cs
@@ -15,7 +15,6 @@ using System.Linq;
 using OpenRA.Graphics;
 using OpenRA.Mods.Common.Orders;
 using OpenRA.Mods.Common.Traits;
-using OpenRA.Mods.Common.Widgets;
 using OpenRA.Primitives;
 using OpenRA.Traits;