--- a/src/tunnelbridge_cmd.cpp	Wed Feb 14 00:57:15 2007 +0000
+++ b/src/tunnelbridge_cmd.cpp	Wed Feb 14 10:46:38 2007 +0000
@@ -1250,7 +1250,10 @@
 static const byte _tunnel_fractcoord_3[4]    = {0x82, 0x88, 0x86, 0x48};
 static const byte _exit_tunnel_track[4]      = {1, 2, 1, 2};
 
-static const byte _road_exit_tunnel_state[4] = {8, 9, 0, 1};
+/** Get the trackdir of the exit of a tunnel */
+static const Trackdir _road_exit_tunnel_state[DIAGDIR_END] = {
+	TRACKDIR_X_SW, TRACKDIR_Y_NW, TRACKDIR_X_NE, TRACKDIR_Y_SE
+};
 static const byte _road_exit_tunnel_frame[4] = {2, 7, 9, 4};
 
 static const byte _tunnel_fractcoord_4[4]    = {0x52, 0x85, 0x98, 0x29};
@@ -1262,7 +1265,7 @@
 {
 	int z = GetSlopeZ(x, y) - v->z_pos;
 
-	if (myabs(z) > 2) return 8;
+	if (myabs(z) > 2) return VETSB_CANNOT_ENTER;
 
 	if (IsTunnel(tile)) {
 		byte fc;
@@ -1275,18 +1278,18 @@
 			dir = GetTunnelDirection(tile);
 			vdir = DirToDiagDir(v->direction);
 
-			if (v->u.rail.track != 0x40 && dir == vdir) {
+			if (v->u.rail.track != TRACK_BIT_WORMHOLE && dir == vdir) {
 				if (IsFrontEngine(v) && fc == _tunnel_fractcoord_1[dir]) {
 					if (!PlayVehicleSound(v, VSE_TUNNEL) && v->spritenum < 4) {
 						SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
 					}
-					return 0;
+					return VETSB_CONTINUE;
 				}
 				if (fc == _tunnel_fractcoord_2[dir]) {
 					v->tile = tile;
 					v->u.rail.track = TRACK_BIT_WORMHOLE;
 					v->vehstatus |= VS_HIDDEN;
-					return 4;
+					return VETSB_ENTERED_WORMHOLE;
 				}
 			}
 
@@ -1296,7 +1299,7 @@
 				v->u.rail.track = (TrackBits)_exit_tunnel_track[dir];
 				assert(v->u.rail.track);
 				v->vehstatus &= ~VS_HIDDEN;
-				return 4;
+				return VETSB_ENTERED_WORMHOLE;
 			}
 		} else if (v->type == VEH_Road) {
 			fc = (x & 0xF) + (y << 4);
@@ -1304,15 +1307,15 @@
 			vdir = DirToDiagDir(v->direction);
 
 			// Enter tunnel?
-			if (v->u.road.state != 0xFF && dir == vdir) {
+			if (v->u.road.state != RVSB_WORMHOLE && dir == vdir) {
 				if (fc == _tunnel_fractcoord_4[dir] ||
 						fc == _tunnel_fractcoord_5[dir]) {
 					v->tile = tile;
-					v->u.road.state = 0xFF;
+					v->u.road.state = RVSB_WORMHOLE;
 					v->vehstatus |= VS_HIDDEN;
-					return 4;
+					return VETSB_ENTERED_WORMHOLE;
 				} else {
-					return 0;
+					return VETSB_CONTINUE;
 				}
 			}
 
@@ -1326,7 +1329,7 @@
 				v->u.road.state = _road_exit_tunnel_state[dir];
 				v->u.road.frame = _road_exit_tunnel_frame[dir];
 				v->vehstatus &= ~VS_HIDDEN;
-				return 4;
+				return VETSB_ENTERED_WORMHOLE;
 			}
 		}
 	} else if (IsBridge(tile)) { // XXX is this necessary?
@@ -1344,37 +1347,37 @@
 		if (DirToDiagDir(v->direction) == dir) {
 			switch (dir) {
 				default: NOT_REACHED();
-				case DIAGDIR_NE: if ((x & 0xF) != 0)             return 0; break;
-				case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
-				case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
-				case DIAGDIR_NW: if ((y & 0xF) != 0)             return 0; break;
+				case DIAGDIR_NE: if ((x & 0xF) != 0)             return VETSB_CONTINUE; break;
+				case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return VETSB_CONTINUE; break;
+				case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return VETSB_CONTINUE; break;
+				case DIAGDIR_NW: if ((y & 0xF) != 0)             return VETSB_CONTINUE; break;
 			}
 			if (v->type == VEH_Train) {
 				v->u.rail.track = TRACK_BIT_WORMHOLE;
 				CLRBIT(v->u.rail.flags, VRF_GOINGUP);
 				CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
 			} else {
-				v->u.road.state = 0xFF;
+				v->u.road.state = RVSB_WORMHOLE;
 			}
-			return 4;
+			return VETSB_ENTERED_WORMHOLE;
 		} else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
 			v->tile = tile;
 			if (v->type == VEH_Train) {
-				if (v->u.rail.track == 0x40) {
+				if (v->u.rail.track == TRACK_BIT_WORMHOLE) {
 					v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y);
-					return 4;
+					return VETSB_ENTERED_WORMHOLE;
 				}
 			} else {
-				if (v->u.road.state == 0xFF) {
+				if (v->u.road.state == RVSB_WORMHOLE) {
 					v->u.road.state = _road_exit_tunnel_state[dir];
 					v->u.road.frame = 0;
-					return 4;
+					return VETSB_ENTERED_WORMHOLE;
 				}
 			}
-			return 0;
+			return VETSB_CONTINUE;
 		}
 	}
-	return 0;
+	return VETSB_CONTINUE;
 }
 
 extern const TileTypeProcs _tile_type_tunnelbridge_procs = {