--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tunnel_map.c Mon Jun 26 15:59:58 2006 +0000
@@ -0,0 +1,31 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "tile.h"
+#include "tunnel_map.h"
+
+static bool IsTunnelInWayDir(TileIndex tile, uint z, DiagDirection dir)
+{
+ TileIndexDiff delta = TileOffsByDir(dir);
+ uint height;
+
+ do {
+ tile -= delta;
+ height = GetTileZ(tile);
+ } while (z < height);
+
+ return
+ z == height &&
+ IsTunnelTile(tile) &&
+ GetTunnelDirection(tile) == dir;
+}
+
+bool IsTunnelInWay(TileIndex tile, uint z)
+{
+ return
+ IsTunnelInWayDir(tile, z, DIAGDIR_NE) ||
+ IsTunnelInWayDir(tile, z, DIAGDIR_SE) ||
+ IsTunnelInWayDir(tile, z, DIAGDIR_SW) ||
+ IsTunnelInWayDir(tile, z, DIAGDIR_NW);
+}