From 5e1c59c3de00e594e7627359588eb66e7ef69511 Mon Sep 17 00:00:00 2001
From: smatz <smatz@openttd.org>
Date: Wed, 10 Jun 2009 14:07:08 +0000
Subject: [PATCH] (svn r16552) -Codechange: make AddTileIndexDiffCWrap() a bit
 faster

---
 src/map_func.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/map_func.h b/src/map_func.h
index 537b1f9a70..1deafc00c3 100644
--- a/src/map_func.h
+++ b/src/map_func.h
@@ -297,10 +297,9 @@ static inline TileIndex AddTileIndexDiffCWrap(TileIndex tile, TileIndexDiffC dif
 {
 	int x = TileX(tile) + diff.x;
 	int y = TileY(tile) + diff.y;
-	if (x < 0 || y < 0 || x > (int)MapMaxX() || y > (int)MapMaxY())
-		return INVALID_TILE;
-	else
-		return TileXY(x, y);
+	/* Negative value will become big positive value after cast */
+	if ((uint)x >= MapSizeX() || (uint)y >= MapSizeY()) return INVALID_TILE;
+	return TileXY(x, y);
 }
 
 /**