(svn r3766) Add a function to get the RoadBits from an arbitrary tile

1 files changed, 44 insertions, 0 deletions

diff --git a/road_map.c b/road_map.c
new file mode 100644
index 000000000..ca35d8358
--- /dev/null
+++ b/road_map.c
@@ -0,0 +1,44 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "road_map.h"
+#include "station.h"
+
+
+RoadBits GetAnyRoadBits(TileIndex tile)
+{
+	switch (GetTileType(tile)) {
+		case MP_STREET:
+			switch (GetRoadType(tile)) {
+				default:
+				case ROAD_NORMAL:   return GetRoadBits(tile);
+				case ROAD_CROSSING: return GetCrossingRoadBits(tile);
+				case ROAD_DEPOT:    return DiagDirToRoadBits(GB(_m[tile].m5, 0, 2));
+			}
+
+		case MP_STATION:
+			if (!IsRoadStationTile(tile)) return 0;
+			return DiagDirToRoadBits(GetRoadStationDir(tile));
+
+		case MP_TUNNELBRIDGE:
+			if (_m[tile].m5 & 0x80) {
+				// bridge
+				if (_m[tile].m5 & 0x40) {
+					// middle part
+					if ((_m[tile].m5 & 0x38) != 0x28) return 0; // no road under bridge
+					return _m[tile].m5 & 1 ? ROAD_X : ROAD_Y;
+				} else {
+					// ending
+					if (GB(_m[tile].m5, 1, 2) != TRANSPORT_ROAD) return 0; // not a road bridge
+					return _m[tile].m5 & 1 ? ROAD_Y : ROAD_X;
+				}
+			} else {
+				// tunnel
+				if (GB(_m[tile].m5, 2, 2) != TRANSPORT_ROAD) return 0; // not a road tunnel
+				return DiagDirToRoadBits(ReverseDiagDir(GB(_m[tile].m5, 0, 2)));
+			}
+
+		default: return 0;
+	}
+}