From a576f304998823248541b37ef413555b5a276315 Mon Sep 17 00:00:00 2001
From: reaperrr <thereaperrr@aol.com>
Date: Sun, 21 Jul 2019 15:39:46 +0200
Subject: [PATCH] Reduce Map.Contains(CPos) cost in legacy mods

If a mod uses rectangular maps and no height levels,
checking if the CPos is within Bounds
should be enough and cheaper than the whole ToMPos
conversion and checks.
---
 OpenRA.Game/Map/Map.cs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/OpenRA.Game/Map/Map.cs b/OpenRA.Game/Map/Map.cs
index cf9cdd120024..af4c29c17803 100644
--- a/OpenRA.Game/Map/Map.cs
+++ b/OpenRA.Game/Map/Map.cs
@@ -752,6 +752,16 @@ public bool Contains(CPos cell)
 			if (Grid.Type == MapGridType.RectangularIsometric && cell.X < cell.Y)
 				return false;
 
+			// If the mod uses flat & rectangular maps, ToMPos and Contains(MPos) create unnecessary cost.
+			// Just check if CPos is within map bounds.
+			if (Grid.MaximumTerrainHeight == 0 && Grid.Type == MapGridType.Rectangular)
+			{
+				if (!Bounds.Contains(cell.X, cell.Y))
+					return false;
+
+				return true;
+			}
+
 			return Contains(cell.ToMPos(this));
 		}