diff --git a/OpenRa.Game/Graphics/Minimap.cs b/OpenRa.Game/Graphics/Minimap.cs
index 73b361938e..a6e4c72a80 100644
--- a/OpenRa.Game/Graphics/Minimap.cs
+++ b/OpenRa.Game/Graphics/Minimap.cs
@@ -97,7 +97,7 @@ namespace OpenRa.Graphics
 				return;
 
 			var bitmap = new Bitmap(oreLayer);
-			var bitmapData = bitmap.LockBits(new Rectangle( 0,0,bitmap.Width, bitmap.Height ), 
+			var bitmapData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height),
 				ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
 
 			unsafe
@@ -105,26 +105,23 @@ namespace OpenRa.Graphics
 				var colors = terrainTypeColors[world.Map.Theater.ToLowerInvariant()];
 				int* c = (int*)bitmapData.Scan0;
 
-				for (var y = 0; y < 128; y++)
-					for (var x = 0; x < 128; x++)
+				foreach (var a in world.Queries.WithTrait<Unit>())
+					*(c + (a.Actor.Location.Y * bitmapData.Stride >> 2) + a.Actor.Location.X) =
+						playerColors[(int)a.Actor.Owner.Palette].ToArgb();
+
+				for (var y = world.Map.YOffset; y < world.Map.YOffset + world.Map.Height; y++)
+					for (var x = world.Map.XOffset; x < world.Map.XOffset + world.Map.Width; x++)
 					{
+						if (!world.LocalPlayer.Shroud.DisplayOnRadar(x, y))
+						{
+							*(c + (y * bitmapData.Stride >> 2) + x) = shroudColor.ToArgb();
+							continue;
+						}
 						var b = world.WorldActor.traits.Get<BuildingInfluence>().GetBuildingAt(new int2(x, y));
 						if (b != null)
 							*(c + (y * bitmapData.Stride >> 2) + x) =
 								(b.Owner != null ? playerColors[(int)b.Owner.Palette] : colors[4]).ToArgb();
 					}
-
-				foreach (var a in world.Queries.WithTrait<Unit>())
-					*(c + (a.Actor.Location.Y * bitmapData.Stride >> 2) + a.Actor.Location.X) =
-						playerColors[(int)a.Actor.Owner.Palette].ToArgb();
-
-				unchecked
-				{
-					for (var y = 0; y < 128; y++)
-						for (var x = 0; x < 128; x++)
-							if (!world.LocalPlayer.Shroud.DisplayOnRadar(x, y))
-								*(c + (y * bitmapData.Stride >> 2) + x) = shroudColor.ToArgb();
-				}
 			}
 
 			bitmap.UnlockBits(bitmapData);
diff --git a/OpenRa.Game/Shroud.cs b/OpenRa.Game/Shroud.cs
index b4534b32ba..e4dea33745 100644
--- a/OpenRa.Game/Shroud.cs
+++ b/OpenRa.Game/Shroud.cs
@@ -21,7 +21,8 @@ namespace OpenRa
 
 		public Shroud(Player owner, Map map) { this.owner = owner; this.map = map; }
 		
-		float gapOpaqueTicks = (int)(Rules.General.GapRegenInterval * 25 * 60);
+		int gapOpaqueTicks = (int)(Rules.General.GapRegenInterval * 25 * 60);
+		int gapTicks;
 		int[,] gapField = new int[128, 128];
 		bool[,] gapActive = new bool[128, 128];
 		
@@ -33,37 +34,25 @@ namespace OpenRa
 
 		public void Tick( World world )
 		{
+			if (gapTicks > 0) { --gapTicks; return; }
+
 			// Clear active flags
 			gapActive = new bool[128, 128];
 			foreach (var a in world.Queries.WithTrait<GeneratesGap>().Where(a => owner != a.Actor.Owner))
-			{
 				foreach (var t in a.Trait.GetShroudedTiles())
-					gapActive[t.X, t.Y] = true;
-			}
-
-			for (int j = 1; j < 127; j++)
-				for (int i = 1; i < 127; i++)
 				{
-					if (gapField[i, j] > 0 && !gapActive[i, j])
-					{
-						// Convert gap to shroud
-						if (gapField[i, j] >= gapOpaqueTicks && explored[i, j])
-							explored[i, j] = false;
-						
-						// Clear gap
-						gapField[i, j] = 0;
-						dirty = true;
-					}
-					// Increase gap tick; rerender if necessary
-					if (gapActive[i, j] && 0 == gapField[i, j]++)
-						dirty = true;
+					gapActive[t.X, t.Y] = true;
+					explored[t.X, t.Y] = false;
+					dirty = true;
 				}
+
+			gapTicks = gapOpaqueTicks;
 		}
 		
 		public bool IsExplored(int2 xy) { return IsExplored(xy.X, xy.Y); }
 		public bool IsExplored(int x, int y)
 		{
-			if (gapField[ x, y ] >= Rules.General.GapRegenInterval * 25 * 60)
+			if (gapField[ x, y ] > 0)
 				return false;
 			
 			if (hasGPS)