CellLayer, use span.

OpenRA.Game/Map/CellLayerBase.cs

@@ -40,19 +40,19 @@ namespace OpenRA
 			if (Size != anotherLayer.Size || GridType != anotherLayer.GridType)
 				throw new ArgumentException("Layers must have a matching size and shape (grid type).", nameof(anotherLayer));
 
-			Array.Copy(anotherLayer.Entries, Entries, Entries.Length);
+			anotherLayer.Entries.AsSpan().CopyTo(Entries);
 		}
 
 		/// <summary>Clears the layer contents with their default value.</summary>
 		public virtual void Clear()
 		{
-			Array.Clear(Entries, 0, Entries.Length);
+			Entries.AsSpan().Clear();
 		}
 
 		/// <summary>Clears the layer contents with a known value.</summary>
 		public virtual void Clear(T clearValue)
 		{
-			Array.Fill(Entries, clearValue);
+			Entries.AsSpan().Fill(clearValue);
 		}
 
 		public IEnumerator<T> GetEnumerator()
@@ -64,5 +64,15 @@ namespace OpenRA
 		{
 			return GetEnumerator();
 		}
+
+		public ReadOnlyMemory<T> AsReadOnlyMemory()
+		{
+			return Entries.AsMemory();
+		}
+
+		public Memory<T> AsMemory()
+		{
+			return Entries.AsMemory();
+		}
 	}
 }

OpenRA.Game/Map/ProjectedCellLayer.cs

@@ -55,14 +55,9 @@ namespace OpenRA
 			return Bounds.Contains(uv.U, uv.V);
 		}
 
-		public int IndexOf(T value, int startIndex)
-		{
-			return Array.IndexOf(Entries, value, startIndex);
-		}
-
 		public void SetAll(T value)
 		{
-			Array.Fill(Entries, value);
+			Entries.AsSpan().Fill(value);
 		}
 	}
 }

OpenRA.Game/Traits/Player/Shroud.cs

@@ -183,12 +183,20 @@ namespace OpenRA.Traits
 			else
 			{
 				// PERF: Most cells are unchanged, use IndexOf for fast vectorized search.
-				var index = touched.IndexOf(true, 0);
+				var span = touched.AsMemory().Span;
+				var index = span.IndexOf(true);
 				while (index != -1)
 				{
-					touched[index] = false;
+					span[index] = false;
 					UpdateCell(index, self);
-					index = touched.IndexOf(true, index + 1);
+
+					if (index < span.Length - 1)
+					{
+						var sliceIndex = span[++index..].IndexOf(true);
+						index = sliceIndex == -1 ? -1 : index + sliceIndex;
+					}
+					else
+						index = -1;
 				}
 			}