Recalculate visibility during moves too.

OpenRA.Mods.Common/Traits/AffectsShroud.cs

@@ -22,6 +22,9 @@ namespace OpenRA.Mods.Common.Traits
 		[Desc("If >= 0, prevent cells that are this much higher than the actor from being revealed.")]
 		public readonly int MaxHeightDelta = -1;
 
+		[Desc("If > 0, force visibility to be recalculated if the unit moves within a cell by more than this distance.")]
+		public readonly WDist MoveRecalculationThreshold = new WDist(256);
+
 		[Desc("Possible values are CenterPosition (measure range from the center) and ",
 			"Footprint (measure range from the footprint)")]
 		public readonly VisibilityType Type = VisibilityType.Footprint;
@@ -43,6 +46,7 @@ namespace OpenRA.Mods.Common.Traits
 		protected bool CachedTraitDisabled { get; private set; }
 
 		bool dirty;
+		WPos cachedPos;
 
 		protected abstract void AddCellsToPlayerShroud(Actor self, Player player, PPos[] uv);
 		protected abstract void RemoveCellsFromPlayerShroud(Actor self, Player player);
@@ -89,6 +93,10 @@ namespace OpenRA.Mods.Common.Traits
 			var projectedLocation = self.World.Map.CellContaining(projectedPos);
 			var traitDisabled = IsTraitDisabled;
 			var range = Range;
+			var pos = self.CenterPosition;
+
+			if (Info.MoveRecalculationThreshold.Length > 0 && (pos - cachedPos).LengthSquared > Info.MoveRecalculationThreshold.LengthSquared)
+				dirty = true;
 
 			if (!dirty && cachedLocation == projectedLocation && cachedRange == range && traitDisabled == CachedTraitDisabled)
 				return;
@@ -96,6 +104,7 @@ namespace OpenRA.Mods.Common.Traits
 			cachedRange = range;
 			cachedLocation = projectedLocation;
 			CachedTraitDisabled = traitDisabled;
+			cachedPos = pos;
 			dirty = false;
 
 			var cells = ProjectedCells(self);