Adjust signal on bridge/tunnel map bits, rename accessors, add docs.

Use same bit to store red/green state for entrances and exits.
No longer re-use exit bit to store red/green state of entrance.
Avoid modifying the M2 of tunnel entrances/exits.
Rename and rationalise map accessor functions.
Document bits used in landscape HTML docs.

docs/landscape.html

@@ -1446,7 +1446,7 @@
      <li>m3 bits 7..4: <a href="#OwnershipInfo">owner</a> of tram</li>
      <li>m3 bits 3..0: <a href="#TrackType">track type</a> for railway</li>
      <li>m5 bit 4: pbs reservation state for railway</li>
-     <li>m5 bits 7 clear: tunnel entrance/exit</li>
+     <li>m5 bit 7 clear: tunnel entrance/exit</li>
      <li>m5 bit 7 set: bridge ramp
       <ul>
        <li>m6 bits 5..2: <a name="BridgeType">bridge type</a>:
@@ -1538,6 +1538,31 @@
        </li>
       </ul>
      </li>
+     <li style="color: blue">m5 bits 6..5: signal simulation (signals on bridge/tunnels patch)
+      <table style="color: blue">
+       <tr>
+        <td><tt>0</tt>&nbsp;</td>
+        <td>no signal simulation</td>
+       </tr>
+
+       <tr>
+        <td><tt>1</tt>&nbsp;</td>
+        <td>signal simulation entrance (bit 5 set)</td>
+       </tr>
+
+       <tr>
+        <td><tt>2</tt>&nbsp;</td>
+        <td>signal simulation exit (bit 6 set)</td>
+       </tr>
+      </table>
+      If signal simulation entrance or exit:
+      <ul>
+       <li>m6 bit 6: set = PBS signals, clear = block signals</li>
+       <li>m6 bit 1: set = semaphore signals, clear = light signals</li>
+       <li>m6 bit 0: set = signal shows green, clear = signal shows red</li>
+       <li>m2 bits 15..0: for bridges only: for signals 0..15 on bridge, signal is visually red if corresponding bit in 0..15 is set</li>
+      </ul>
+     </li>
      <li>m5 bits 3..2: transport type
       <table>
        <tr>

docs/landscape_grid.html

@@ -9,6 +9,7 @@
     span.option{ font-family: "Courier New", Courier, mono; background-color: rgb(255,255, 30); }
     span.free  { font-family: "Courier New", Courier, mono; background-color: rgb(30, 178, 54); }
     span.used  { font-family: "Courier New", Courier, mono; }
+    span.used_p{ font-family: "Courier New", Courier, mono; background-color: cyan; }
     td.bits    { white-space: nowrap; text-align: center; font-family: "Courier New", Courier, mono; }
     td.caption { white-space: nowrap; text-align: left; }
     td li      { white-space: nowrap; text-align: left; }
@@ -23,6 +24,7 @@ the array so you can quickly see what is used and what is not.
 <ul>
   <li><span style="font-weight: bold;"><span class="free">O</span></span> - bit is free</li>
   <li><span style="font-weight: bold;"><span class="used">X</span></span> - bit is used</li>
+  <li><span style="font-weight: bold;"><span class="used_p">P</span></span> - bit is used by patch feature</li>
   <li><span style="font-weight: bold;"><span class="abuse">&nbsp;</span></span> - bit of attribute is abused for different purposes, i.e. other bits define the actual meaning.</li>
   <li><span style="font-weight: bold;"><span class="option">~</span></span> - bit is accessed, but does not really have a meaning (e.g. owner of clear land is always OWNER_NONE)</li>
 </ul>
@@ -334,8 +336,8 @@ the array so you can quickly see what is used and what is not.
       <td class="bits"><span class="free">OOOO OOOO OOOO OOOO</span></td>
       <td class="bits">XXXX XXXX</td>
       <td class="bits"><span class="free">OOOO OOOO</span></td>
-      <td class="bits">X<span class="free">OO</span>X XXXX</td>
-      <td class="bits"><span class="free">OOOO OOOO</span></td>
+      <td class="bits">X<span class="used_p">PP</span>X XXXX</td>
+      <td class="bits"><span class="free">O</span><span class="used_p">P</span><span class="free">OO OO</span><span class="used_p">PP</span></td>
       <td class="bits">XXXX XXXX</td>
     </tr>
     <tr>
@@ -343,11 +345,11 @@ the array so you can quickly see what is used and what is not.
       <td class="bits">-inherit-</td>
       <td class="bits">-inherit-</td>
       <td class="bits">-inherit-</td>
+      <td class="bits"><span class="used_p">PPPP PPPP PPPP PPPP</span></td>
       <td class="bits">-inherit-</td>
       <td class="bits">-inherit-</td>
       <td class="bits">-inherit-</td>
-      <td class="bits">-inherit-</td>
-      <td class="bits"><span class="free">OO</span>XX XX<span class="free">OO</span></td>
+      <td class="bits"><span class="free">O</span><span class="used_p">P</span>XX XX<span class="used_p">PP</span></td>
       <td class="bits">-inherit-</td>
     </tr>
     <tr>

src/pathfinder/npf/npf.cpp

@@ -936,7 +936,7 @@ static void NPFFollowTrack(AyStar *aystar, OpenListNode *current)
 				break;
 			}
 		}
-		if (IsTileType(dst_tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(dst_tile) && DiagDirToDiagTrackdir(GetTunnelBridgeDirection(dst_tile)) == dst_trackdir) {
+		if (IsTileType(dst_tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(dst_tile) && DiagDirToDiagTrackdir(GetTunnelBridgeDirection(dst_tile)) == dst_trackdir) {
 			/* Entering a signalled bridge/tunnel from the wrong side, equivalent to encountering a one-way signal from the wrong side */
 			break;
 		}

src/pathfinder/yapf/yapf_costrail.hpp

@@ -244,7 +244,7 @@ public:
 				}
 			}
 		}
-		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(tile) && DiagDirToDiagTrackdir(GetTunnelBridgeDirection(tile)) == trackdir) {
+		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(tile) && DiagDirToDiagTrackdir(GetTunnelBridgeDirection(tile)) == trackdir) {
 			/* Entering a signalled bridge/tunnel from the wrong side, equivalent to encountering a one-way signal from the wrong side */
 			n.m_segment->m_end_segment_reason |= ESRB_DEAD_END;
 		}

src/pbs.cpp

@@ -125,7 +125,7 @@ bool TryReserveRailTrack(TileIndex tile, Track t, bool trigger_stations)
 		case MP_TUNNELBRIDGE:
 			if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL && !GetTunnelBridgeReservationTrackBits(tile)) {
 				SetTunnelBridgeReservation(tile, true);
-				if (IsTunnelBridgeExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeExitGreen(tile, true);
+				if (IsTunnelBridgeSignalSimulationExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 				MarkTileDirtyByTile(tile);
 				return true;
 			}
@@ -181,7 +181,7 @@ void UnreserveRailTrack(TileIndex tile, Track t)
 		case MP_TUNNELBRIDGE:
 			if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
 				SetTunnelBridgeReservation(tile, false);
-				if (IsTunnelBridgeExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeExitGreen(tile, false);
+				if (IsTunnelBridgeSignalSimulationExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeSignalState(tile, SIGNAL_STATE_RED);
 				MarkTileDirtyByTile(tile);
 			}
 			break;
@@ -252,7 +252,7 @@ static PBSTileInfo FollowReservation(Owner o, RailTypes rts, TileIndex tile, Tra
 		if (IsRailDepotTile(tile)) break;
 		/* Non-pbs signal? Reservation can't continue. */
 		if (IsTileType(tile, MP_RAILWAY) && HasSignalOnTrackdir(tile, trackdir) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) break;
-		if (IsTileType(tile, MP_TUNNELBRIDGE) && HasWormholeSignals(tile)) break;
+		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeWithSignalSimulation(tile)) break;
 	}
 
 	return PBSTileInfo(tile, trackdir, false);
@@ -281,7 +281,7 @@ static Vehicle *FindTrainOnTrackEnum(Vehicle *v, void *data)
 		/* Do not find trains inside signalled bridge/tunnels.
 		 * Trains on the ramp/entrance itself are found though.
 		 */
-		if (IsTileType(info->res.tile, MP_TUNNELBRIDGE) && HasWormholeSignals(info->res.tile) && info->res.tile != TileVirtXY(t->x_pos, t->y_pos)) {
+		if (IsTileType(info->res.tile, MP_TUNNELBRIDGE) && IsTunnelBridgeWithSignalSimulation(info->res.tile) && info->res.tile != TileVirtXY(t->x_pos, t->y_pos)) {
 			return NULL;
 		}
 	}
@@ -329,7 +329,7 @@ PBSTileInfo FollowTrainReservation(const Train *v, Vehicle **train_on_res)
 				if (ftoti.best != NULL) *train_on_res = ftoti.best->First();
 			}
 		}
-		if (*train_on_res == NULL && IsTileType(ftoti.res.tile, MP_TUNNELBRIDGE) && !HasWormholeSignals(ftoti.res.tile)) {
+		if (*train_on_res == NULL && IsTileType(ftoti.res.tile, MP_TUNNELBRIDGE) && !IsTunnelBridgeWithSignalSimulation(ftoti.res.tile)) {
 			/* The target tile is a bridge/tunnel, also check the other end tile. */
 			FindVehicleOnPos(GetOtherTunnelBridgeEnd(ftoti.res.tile), &ftoti, FindTrainOnTrackEnum);
 			if (ftoti.best != NULL) *train_on_res = ftoti.best->First();
@@ -405,7 +405,7 @@ bool IsSafeWaitingPosition(const Train *v, TileIndex tile, Trackdir trackdir, bo
 	}
 
 	if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {
-		if (IsTunnelBridgeEntrance(tile)) {
+		if (IsTunnelBridgeSignalSimulationEntrance(tile)) {
 			return true;
 		}
 	}
@@ -458,7 +458,7 @@ bool IsWaitingPositionFree(const Train *v, TileIndex tile, Trackdir trackdir, bo
 	/* Not reserved and depot or not a pbs signal -> free. */
 	if (IsRailDepotTile(tile)) return true;
 	if (IsTileType(tile, MP_RAILWAY) && HasSignalOnTrackdir(tile, trackdir) && !IsPbsSignal(GetSignalType(tile, track))) return true;
-	if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL && IsTunnelBridgeEntrance(tile)) return true;
+	if (IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL && IsTunnelBridgeSignalSimulationEntrance(tile)) return true;
 
 	/* Check the next tile, if it's a PBS signal, it has to be free as well. */
 	CFollowTrackRail ft(v, GetRailTypeInfo(v->railtype)->compatible_railtypes);

src/rail_cmd.cpp

@@ -1061,7 +1061,7 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 		cost = CommandCost();
 		bool flip_variant = false;
 		bool is_pbs = (sigtype == SIGTYPE_PBS) || (sigtype == SIGTYPE_PBS_ONEWAY);
-		if (!HasWormholeSignals(tile)) { // toggle signal zero costs.
+		if (!IsTunnelBridgeWithSignalSimulation(tile)) { // toggle signal zero costs.
 			if (convert_signal) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
 			if (p2 != 12) cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] * ((GetTunnelBridgeLength(tile, tile_exit) + 4) >> 2)); // minimal 1
 		} else {
@@ -1074,7 +1074,7 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 			}
 		}
 		if (flags & DC_EXEC) {
-			if (p2 == 0 && HasWormholeSignals(tile)) { // Toggle signal if already signals present.
+			if (p2 == 0 && IsTunnelBridgeWithSignalSimulation(tile)) { // Toggle signal if already signals present.
 				if (convert_signal) {
 					if (flip_variant) {
 						SetTunnelBridgeSemaphore(tile, !IsTunnelBridgeSemaphore(tile));
@@ -1088,37 +1088,42 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 					SetTunnelBridgePBS(tile, !IsTunnelBridgePBS(tile));
 					SetTunnelBridgePBS(tile_exit, IsTunnelBridgePBS(tile));
 				} else {
-					if (IsTunnelBridgeEntrance(tile)) {
-						ClrBitTunnelBridgeSignal(tile);
-						ClrBitTunnelBridgeExit(tile_exit);
-						SetBitTunnelBridgeExit(tile);
-						SetBitTunnelBridgeSignal(tile_exit);
+					if (IsTunnelBridgeSignalSimulationEntrance(tile)) {
+						ClrTunnelBridgeSignalSimulationEntrance(tile);
+						ClrTunnelBridgeSignalSimulationExit(tile_exit);
+						SetTunnelBridgeSignalSimulationExit(tile);
+						SetTunnelBridgeSignalSimulationEntrance(tile_exit);
+						SetTunnelBridgeSignalState(tile_exit, SIGNAL_STATE_GREEN);
 					} else {
-						ClrBitTunnelBridgeSignal(tile_exit);
-						ClrBitTunnelBridgeExit(tile);
-						SetBitTunnelBridgeExit(tile_exit);
-						SetBitTunnelBridgeSignal(tile);
+						ClrTunnelBridgeSignalSimulationEntrance(tile_exit);
+						ClrTunnelBridgeSignalSimulationExit(tile);
+						SetTunnelBridgeSignalSimulationExit(tile_exit);
+						SetTunnelBridgeSignalSimulationEntrance(tile);
+						SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 					}
 				}
 			} else {
 				/* Create one direction tunnel/bridge if required. */
 				if (p2 == 0) {
-					SetBitTunnelBridgeSignal(tile);
-					SetBitTunnelBridgeExit(tile_exit);
+					SetTunnelBridgeSignalSimulationEntrance(tile);
+					SetTunnelBridgeSignalSimulationExit(tile_exit);
+					SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 				} else if (p2 == 4 || p2 == 8) {
 					DiagDirection tbdir = GetTunnelBridgeDirection(tile);
 					/* If signal only on one side build accoringly one-way tunnel/bridge. */
 					if ((p2 == 8 && (tbdir == DIAGDIR_NE || tbdir == DIAGDIR_SE)) ||
 						(p2 == 4 && (tbdir == DIAGDIR_SW || tbdir == DIAGDIR_NW))) {
-						ClrBitTunnelBridgeExit(tile);
-						ClrBitTunnelBridgeSignal(tile_exit);
-						SetBitTunnelBridgeSignal(tile);
-						SetBitTunnelBridgeExit(tile_exit);
+						ClrTunnelBridgeSignalSimulationExit(tile);
+						ClrTunnelBridgeSignalSimulationEntrance(tile_exit);
+						SetTunnelBridgeSignalSimulationEntrance(tile);
+						SetTunnelBridgeSignalSimulationExit(tile_exit);
+						SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 					} else {
-						ClrBitTunnelBridgeSignal(tile);
-						ClrBitTunnelBridgeExit(tile_exit);
-						SetBitTunnelBridgeSignal(tile_exit);
-						SetBitTunnelBridgeExit(tile);
+						ClrTunnelBridgeSignalSimulationEntrance(tile);
+						ClrTunnelBridgeSignalSimulationExit(tile_exit);
+						SetTunnelBridgeSignalSimulationEntrance(tile_exit);
+						SetTunnelBridgeSignalSimulationExit(tile);
+						SetTunnelBridgeSignalState(tile_exit, SIGNAL_STATE_GREEN);
 					}
 				}
 				if (p2 == 0 || p2 == 4 || p2 == 8) {
@@ -1128,8 +1133,8 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 					SetTunnelBridgePBS(tile_exit, is_pbs);
 				}
 			}
-			if (IsTunnelBridgeExit(tile) && IsTunnelBridgePBS(tile) && !HasTunnelBridgeReservation(tile)) SetTunnelBridgeExitGreen(tile, false);
-			if (IsTunnelBridgeExit(tile_exit) && IsTunnelBridgePBS(tile_exit) && !HasTunnelBridgeReservation(tile_exit)) SetTunnelBridgeExitGreen(tile_exit, false);
+			if (IsTunnelBridgeSignalSimulationExit(tile) && IsTunnelBridgePBS(tile) && !HasTunnelBridgeReservation(tile)) SetTunnelBridgeSignalState(tile, SIGNAL_STATE_RED);
+			if (IsTunnelBridgeSignalSimulationExit(tile_exit) && IsTunnelBridgePBS(tile_exit) && !HasTunnelBridgeReservation(tile_exit)) SetTunnelBridgeSignalState(tile_exit, SIGNAL_STATE_RED);
 			MarkBridgeOrTunnelDirty(tile);
 			AddSideToSignalBuffer(tile, INVALID_DIAGDIR, GetTileOwner(tile));
 			AddSideToSignalBuffer(tile_exit, INVALID_DIAGDIR, GetTileOwner(tile));
@@ -1305,7 +1310,7 @@ static bool CheckSignalAutoFill(TileIndex &tile, Trackdir &trackdir, int &signal
 			return true;
 
 		case MP_TUNNELBRIDGE: {
-			if (!remove && HasWormholeSignals(tile)) return false;
+			if (!remove && IsTunnelBridgeWithSignalSimulation(tile)) return false;
 			TileIndex orig_tile = tile; // backup old value
 
 			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return false;
@@ -1556,7 +1561,7 @@ CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1
 	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
 		TileIndex end = GetOtherTunnelBridgeEnd(tile);
 		if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
-		if (!HasWormholeSignals(tile)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
+		if (!IsTunnelBridgeWithSignalSimulation(tile)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
 
 		cost *= ((GetTunnelBridgeLength(tile, end) + 4) >> 2);
 
@@ -1584,12 +1589,12 @@ CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1
 	/* Do it? */
 	if (flags & DC_EXEC) {
 
-		if (HasWormholeSignals(tile)) { // handle tunnel/bridge signals.
+		if (IsTunnelBridgeWithSignalSimulation(tile)) { // handle tunnel/bridge signals.
 			TileIndex end = GetOtherTunnelBridgeEnd(tile);
-			ClrBitTunnelBridgeExit(tile);
-			ClrBitTunnelBridgeExit(end);
-			ClrBitTunnelBridgeSignal(tile);
-			ClrBitTunnelBridgeSignal(end);
+			ClrTunnelBridgeSignalSimulationExit(tile);
+			ClrTunnelBridgeSignalSimulationExit(end);
+			ClrTunnelBridgeSignalSimulationEntrance(tile);
+			ClrTunnelBridgeSignalSimulationEntrance(end);
 			_m[tile].m2 = 0;
 			_m[end].m2 = 0;
 			MarkBridgeOrTunnelDirty(tile);

src/rail_map.h

@@ -480,7 +480,7 @@ static inline bool HasOnewaySignalBlockingTrackdir(TileIndex tile, Trackdir td)
 			!HasSignalOnTrackdir(tile, td) && IsOnewaySignal(tile, TrackdirToTrack(td))) {
 		return true;
 	}
-	if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(tile) &&
+	if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(tile) &&
 			DiagDirToDiagTrackdir(GetTunnelBridgeDirection(tile)) == td) {
 		return true;
 	}

src/saveload/afterload.cpp

@@ -2972,13 +2972,28 @@ bool AfterLoadGame()
 		/* set the semaphore bit to match what it would have been in v1 */
 		/* clear the PBS bit, update the end signal state */
 		for (TileIndex t = 0; t < map_size; t++) {
-			if (IsTileType(t, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(t) == TRANSPORT_RAIL && HasWormholeSignals(t)) {
+			if (IsTileType(t, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(t) == TRANSPORT_RAIL && IsTunnelBridgeWithSignalSimulation(t)) {
 				SetTunnelBridgeSemaphore(t, _cur_year < _settings_client.gui.semaphore_build_before);
 				SetTunnelBridgePBS(t, false);
 				UpdateSignalsOnSegment(t, INVALID_DIAGDIR, GetTileOwner(t));
 			}
 		}
 	}
+	if (SlXvIsFeaturePresent(XSLFI_SIG_TUNNEL_BRIDGE, 1, 2)) {
+		/* red/green signal state bit for tunnel entrances moved
+		 * to no longer re-use signalled tunnel exit bit
+		 */
+		for (TileIndex t = 0; t < map_size; t++) {
+			if (IsTileType(t, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(t) == TRANSPORT_RAIL && IsTunnelBridgeWithSignalSimulation(t)) {
+				if (HasBit(_m[t].m5, 5)) {
+					/* signalled tunnel entrance */
+					SignalState state = HasBit(_m[t].m5, 6) ? SIGNAL_STATE_RED : SIGNAL_STATE_GREEN;
+					ClrBit(_m[t].m5, 6);
+					SetTunnelBridgeSignalState(t, state);
+				}
+			}
+		}
+	}
 
 	/* Station acceptance is some kind of cache */
 	if (IsSavegameVersionBefore(127)) {

src/saveload/extended_ver_sl.cpp

@@ -45,7 +45,7 @@ std::vector<uint32> _sl_xv_discardable_chunk_ids;           ///< list of chunks
 static const uint32 _sl_xv_slxi_chunk_version = 0;          ///< current version os SLXI chunk
 
 const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
-	{ XSLFI_SIG_TUNNEL_BRIDGE,      XSCF_NULL,                2,   2, "signal_tunnel_bridge",      NULL, NULL, NULL        },
+	{ XSLFI_SIG_TUNNEL_BRIDGE,      XSCF_NULL,                3,   3, "signal_tunnel_bridge",      NULL, NULL, NULL        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
 };
 

src/signal.cpp

@@ -384,13 +384,13 @@ static SigFlags ExploreSegment(Owner owner)
 				if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;
 				DiagDirection dir = GetTunnelBridgeDirection(tile);
 
-				if (HasWormholeSignals(tile)) {
+				if (IsTunnelBridgeWithSignalSimulation(tile)) {
 					if (enterdir == INVALID_DIAGDIR) { // incoming from the wormhole
-						if (!(flags & SF_TRAIN) && IsTunnelBridgeExit(tile)) { // tunnel entrence is ignored
+						if (!(flags & SF_TRAIN) && IsTunnelBridgeSignalSimulationExit(tile)) { // tunnel entrence is ignored
 							if (HasVehicleOnPos(GetOtherTunnelBridgeEnd(tile), &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 							if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 						}
-						if (IsTunnelBridgeExit(tile) && !_tbuset.Add(tile, INVALID_TRACKDIR)) {
+						if (IsTunnelBridgeSignalSimulationExit(tile) && !_tbuset.Add(tile, INVALID_TRACKDIR)) {
 							return flags | SF_FULL;
 						}
 						enterdir = dir;
@@ -398,7 +398,7 @@ static SigFlags ExploreSegment(Owner owner)
 						tile += TileOffsByDiagDir(exitdir); // just skip to next tile
 					} else { // NOT incoming from the wormhole!
 						if (ReverseDiagDir(enterdir) != dir) continue;
-						if (IsTunnelBridgeExit(tile)) {
+						if (IsTunnelBridgeSignalSimulationExit(tile)) {
 							if (IsTunnelBridgePBS(tile)) {
 								flags |= SF_PBS;
 							} else if (!_tbuset.Add(tile, INVALID_TRACKDIR)) {
@@ -407,7 +407,7 @@ static SigFlags ExploreSegment(Owner owner)
 						}
 						if (!(flags & SF_TRAIN)) {
 							if (HasVehicleOnPos(tile, &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
-							if (!(flags & SF_TRAIN) && IsTunnelBridgeExit(tile)) {
+							if (!(flags & SF_TRAIN) && IsTunnelBridgeSignalSimulationExit(tile)) {
 								if (HasVehicleOnPos(GetOtherTunnelBridgeEnd(tile), &tile, &TrainInWormholeTileEnum)) flags |= SF_TRAIN;
 							}
 						}
@@ -453,12 +453,12 @@ static void UpdateSignalsAroundSegment(SigFlags flags)
 	Trackdir trackdir;
 
 	while (_tbuset.Get(&tile, &trackdir)) {
-		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(tile)) {
+		if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(tile)) {
 			if (IsTunnelBridgePBS(tile)) continue;
-			bool old_state = IsTunnelBridgeExitGreen(tile);
-			bool new_state = !(flags & SF_TRAIN);
+			SignalState old_state = GetTunnelBridgeSignalState(tile);
+			SignalState new_state = (flags & SF_TRAIN) ? SIGNAL_STATE_RED : SIGNAL_STATE_GREEN;
 			if (old_state != new_state) {
-				SetTunnelBridgeExitGreen(tile, new_state);
+				SetTunnelBridgeSignalState(tile, new_state);
 				MarkTileDirtyByTile(tile);
 			}
 			continue;
@@ -545,7 +545,7 @@ static SigSegState UpdateSignalsInBuffer(Owner owner)
 				assert(GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL);
 				assert(dir == INVALID_DIAGDIR || dir == ReverseDiagDir(GetTunnelBridgeDirection(tile)));
 				_tbdset.Add(tile, INVALID_DIAGDIR);  // we can safely start from wormhole centre
-				if (!HasWormholeSignals(tile)) {  // Don't worry with other side of tunnel.
+				if (!IsTunnelBridgeWithSignalSimulation(tile)) {  // Don't worry with other side of tunnel.
 					_tbdset.Add(GetOtherTunnelBridgeEnd(tile), INVALID_DIAGDIR);
 				}
 				break;

src/train_cmd.cpp

@@ -1864,9 +1864,9 @@ void ReverseTrainDirection(Train *v)
 	}
 
 	/* We are inside tunnel/bidge with signals, reversing will close the entrance. */
-	if (HasWormholeSignals(v->tile)) {
+	if (IsTunnelBridgeWithSignalSimulation(v->tile)) {
 		/* Flip signal on tunnel entrance tile red. */
-		SetBitTunnelBridgeExit(v->tile);
+		SetTunnelBridgeSignalState(v->tile, SIGNAL_STATE_RED);
 		MarkTileDirtyByTile(v->tile);
 		/* Clear counters. */
 		v->wait_counter = 0;
@@ -2233,14 +2233,16 @@ static void HandleLastTunnelBridgeSignals(TileIndex tile, TileIndex end, DiagDir
 	}
 	if (free) {
 	/* Open up the wormhole and clear m2. */
-		_m[tile].m2 = 0;
-		_m[end].m2 = 0;
+		if (IsBridge(end)) {
+			_m[tile].m2 = 0;
+			_m[end].m2 = 0;
+		}
 
-		if (IsTunnelBridgeWithSignRed(end)) {
-			ClrBitTunnelBridgeExit(end);
+		if (IsTunnelBridgeSignalSimulationEntrance(end) && GetTunnelBridgeSignalState(end) == SIGNAL_STATE_RED) {
+			SetTunnelBridgeSignalState(end, SIGNAL_STATE_GREEN);
 			if (!_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(end);
-		} else if (IsTunnelBridgeWithSignRed(tile)) {
-			ClrBitTunnelBridgeExit(tile);
+		} else if (IsTunnelBridgeSignalSimulationEntrance(tile) && GetTunnelBridgeSignalState(tile) == SIGNAL_STATE_RED) {
+			SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 			if (!_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(tile);
 		}
 	}
@@ -2249,7 +2251,7 @@ static void HandleLastTunnelBridgeSignals(TileIndex tile, TileIndex end, DiagDir
 static void UnreserveBridgeTunnelTile(TileIndex tile)
 {
 	SetTunnelBridgeReservation(tile, false);
-	if (IsTunnelBridgeExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeExitGreen(tile, false);
+	if (IsTunnelBridgeSignalSimulationExit(tile) && IsTunnelBridgePBS(tile)) SetTunnelBridgeSignalState(tile, SIGNAL_STATE_RED);
 }
 
 /**
@@ -2268,7 +2270,7 @@ static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_
 			TileIndex end = GetOtherTunnelBridgeEnd(tile);
 
 			bool free = TunnelBridgeIsFree(tile, end, v).Succeeded();
-			if (HasWormholeSignals(tile)) {
+			if (IsTunnelBridgeWithSignalSimulation(tile)) {
 				UnreserveBridgeTunnelTile(tile);
 				HandleLastTunnelBridgeSignals(tile, end, dir, free);
 				if (_settings_client.gui.show_track_reservation) {
@@ -2288,7 +2290,7 @@ static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_
 					}
 				}
 			}
-		} else if (GetTunnelBridgeDirection(tile) == dir && HasWormholeSignals(tile)) {
+		} else if (GetTunnelBridgeDirection(tile) == dir && IsTunnelBridgeWithSignalSimulation(tile)) {
 			/* cancelling reservation of entry ramp, due to reverse */
 			UnreserveBridgeTunnelTile(tile);
 			if (_settings_client.gui.show_track_reservation) {
@@ -2769,7 +2771,7 @@ bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
 		}
 	}
 
-	if (IsTileType(v->tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(v->tile) &&
+	if (IsTileType(v->tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(v->tile) &&
 			DiagDirToDiagTrackBits(GetTunnelBridgeDirection(v->tile)) == v->track) {
 		// prevent any attempt to reserve the wrong way onto a tunnel/bridge exit
 		return false;
@@ -2980,7 +2982,7 @@ static bool TrainMovedChangeSignals(TileIndex tile, DiagDirection dir)
 			if (!IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
 		}
 	}
-	if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeExit(tile) && GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
+	if (IsTileType(tile, MP_TUNNELBRIDGE) && IsTunnelBridgeSignalSimulationExit(tile) && GetTunnelBridgeDirection(tile) == ReverseDiagDir(dir)) {
 		if (UpdateSignalsOnSegment(tile, dir, GetTileOwner(tile)) == SIGSEG_PBS) {
 			return true;
 		}
@@ -3247,7 +3249,7 @@ static bool CheckTrainStayInWormHole(Train *t, TileIndex tile)
 	if (t->force_proceed != 0) return false;
 
 	/* When not exit reverse train. */
-	if (!IsTunnelBridgeExit(tile)) {
+	if (!IsTunnelBridgeSignalSimulationExit(tile)) {
 		t->cur_speed = 0;
 		ToggleBit(t->flags, VRF_REVERSING);
 		return true;
@@ -3287,8 +3289,8 @@ static void HandleSignalBehindTrain(Train *v, uint signal_number)
 
 	if(tile == v->tile) {
 		/* Flip signal on ramp. */
-		if (IsTunnelBridgeWithSignRed(tile)) {
-			ClrBitTunnelBridgeExit(tile);
+		if (IsTunnelBridgeSignalSimulationEntrance(tile) && GetTunnelBridgeSignalState(tile) == SIGNAL_STATE_RED) {
+			SetTunnelBridgeSignalState(tile, SIGNAL_STATE_GREEN);
 			MarkTileDirtyByTile(tile);
 		}
 	} else if (IsBridge(v->tile) && signal_number <= 16) {
@@ -3482,20 +3484,20 @@ bool TrainController(Train *v, Vehicle *nomove, bool reverse)
 					goto invalid_rail;
 				}
 
-				if (HasWormholeSignals(gp.new_tile)) {
+				if (IsTunnelBridgeWithSignalSimulation(gp.new_tile)) {
 					/* If red signal stop. */
 					if (v->IsFrontEngine() && v->force_proceed == 0) {
-						if (IsTunnelBridgeWithSignRed(gp.new_tile)) {
+						if (IsTunnelBridgeSignalSimulationEntrance(gp.new_tile) && GetTunnelBridgeSignalState(gp.new_tile) == SIGNAL_STATE_RED) {
 							v->cur_speed = 0;
 							v->vehstatus |= VS_TRAIN_SLOWING;
 							return false;
 						}
-						if (IsTunnelBridgeExit(gp.new_tile)) {
+						if (IsTunnelBridgeSignalSimulationExit(gp.new_tile)) {
 							v->cur_speed = 0;
 							goto invalid_rail;
 						}
 						/* Flip signal on tunnel entrance tile red. */
-						SetBitTunnelBridgeExit(gp.new_tile);
+						SetTunnelBridgeSignalState(gp.new_tile, SIGNAL_STATE_RED);
 						MarkTileDirtyByTile(gp.new_tile);
 					}
 				}
@@ -3554,9 +3556,9 @@ bool TrainController(Train *v, Vehicle *nomove, bool reverse)
 		} else {
 			/* Handle signal simulation on tunnel/bridge. */
 			TileIndex old_tile = TileVirtXY(v->x_pos, v->y_pos);
-			if (old_tile != gp.new_tile && HasWormholeSignals(v->tile) && (v->IsFrontEngine() || v->Next() == NULL)) {
+			if (old_tile != gp.new_tile && IsTunnelBridgeWithSignalSimulation(v->tile) && (v->IsFrontEngine() || v->Next() == NULL)) {
 				if (old_tile == v->tile) {
-					if (v->IsFrontEngine() && v->force_proceed == 0 && IsTunnelBridgeExit(v->tile)) goto invalid_rail;
+					if (v->IsFrontEngine() && v->force_proceed == 0 && IsTunnelBridgeSignalSimulationExit(v->tile)) goto invalid_rail;
 					/* Entered wormhole set counters. */
 					v->wait_counter = (TILE_SIZE * _settings_game.construction.simulated_wormhole_signals) - TILE_SIZE;
 					v->load_unload_ticks = 0;

src/tunnelbridge_cmd.cpp

@@ -1166,15 +1166,13 @@ static void DrawTunnelBridgeRampSignal(const TileInfo *ti)
 
 	SignalType type = SIGTYPE_NORMAL;
 
-	bool is_green;
+	bool is_green = (GetTunnelBridgeSignalState(ti->tile) == SIGNAL_STATE_GREEN);
 	bool show_exit;
-	if (IsTunnelBridgeExit(ti->tile)) {
-		is_green = IsTunnelBridgeExitGreen(ti->tile);
+	if (IsTunnelBridgeSignalSimulationExit(ti->tile)) {
 		show_exit = true;
 		position ^= 1;
 		if (IsTunnelBridgePBS(ti->tile)) type = SIGTYPE_PBS_ONEWAY;
 	} else {
-		is_green = IsTunnelBridgeWithSignGreen(ti->tile);
 		show_exit = false;
 	}
 
@@ -1369,7 +1367,7 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x + BB_data[4], ti->y + BB_data[5], BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);
 
 		/* Draw signals for tunnel. */
-		if (HasWormholeSignals(ti->tile)) DrawTunnelBridgeRampSignal(ti);
+		if (IsTunnelBridgeWithSignalSimulation(ti->tile)) DrawTunnelBridgeRampSignal(ti);
 
 		DrawBridgeMiddle(ti);
 	} else { // IsBridge(ti->tile)
@@ -1479,7 +1477,7 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		}
 
 		/* Draw signals for bridge. */
-		if (HasWormholeSignals(ti->tile)) DrawTunnelBridgeRampSignal(ti);
+		if (IsTunnelBridgeWithSignalSimulation(ti->tile)) DrawTunnelBridgeRampSignal(ti);
 
 		DrawBridgeMiddle(ti);
 	}
@@ -1616,7 +1614,7 @@ void DrawBridgeMiddle(const TileInfo *ti)
 		}
 
 		if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && !IsInvisibilitySet(TO_BRIDGES) && HasTunnelBridgeReservation(rampnorth)
-				&& !HasWormholeSignals(rampnorth)) {
+				&& !IsTunnelBridgeWithSignalSimulation(rampnorth)) {
 			if (rti->UsesOverlay()) {
 				SpriteID overlay = GetCustomRailSprite(rti, ti->tile, RTSG_OVERLAY);
 				AddSortableSpriteToDraw(overlay + RTO_X + axis, PALETTE_CRASH, ti->x, ti->y, 16, 16, 0, bridge_z, IsTransparencySet(TO_BRIDGES));
@@ -1630,8 +1628,8 @@ void DrawBridgeMiddle(const TileInfo *ti)
 		if (HasCatenaryDrawn(GetRailType(rampsouth))) {
 			DrawCatenaryOnBridge(ti);
 		}
-		if (HasWormholeSignals(rampsouth)) {
-			IsTunnelBridgeExit(rampsouth) ? DrawBrigeSignalOnMiddlePart(ti, rampnorth, z): DrawBrigeSignalOnMiddlePart(ti, rampsouth, z);
+		if (IsTunnelBridgeWithSignalSimulation(rampsouth)) {
+			IsTunnelBridgeSignalSimulationExit(rampsouth) ? DrawBrigeSignalOnMiddlePart(ti, rampnorth, z): DrawBrigeSignalOnMiddlePart(ti, rampsouth, z);
 		}
 	}
 
@@ -1721,9 +1719,9 @@ static void GetTileDesc_TunnelBridge(TileIndex tile, TileDesc *td)
 	TransportType tt = GetTunnelBridgeTransportType(tile);
 
 	if (IsTunnel(tile)) {
-		td->str = (tt == TRANSPORT_RAIL) ? HasWormholeSignals(tile) ? STR_LAI_TUNNEL_DESCRIPTION_RAILROAD_SIGNAL : STR_LAI_TUNNEL_DESCRIPTION_RAILROAD : STR_LAI_TUNNEL_DESCRIPTION_ROAD;
+		td->str = (tt == TRANSPORT_RAIL) ? IsTunnelBridgeWithSignalSimulation(tile) ? STR_LAI_TUNNEL_DESCRIPTION_RAILROAD_SIGNAL : STR_LAI_TUNNEL_DESCRIPTION_RAILROAD : STR_LAI_TUNNEL_DESCRIPTION_ROAD;
 	} else { // IsBridge(tile)
-		td->str = (tt == TRANSPORT_WATER) ? STR_LAI_BRIDGE_DESCRIPTION_AQUEDUCT : HasWormholeSignals(tile) ? STR_LAI_BRIDGE_DESCRIPTION_RAILROAD_SIGNAL : GetBridgeSpec(GetBridgeType(tile))->transport_name[tt];
+		td->str = (tt == TRANSPORT_WATER) ? STR_LAI_BRIDGE_DESCRIPTION_AQUEDUCT : IsTunnelBridgeWithSignalSimulation(tile) ? STR_LAI_BRIDGE_DESCRIPTION_RAILROAD_SIGNAL : GetBridgeSpec(GetBridgeType(tile))->transport_name[tt];
 	}
 	td->owner[0] = GetTileOwner(tile);
 

src/tunnelbridge_map.h

@@ -14,6 +14,7 @@
 
 #include "bridge_map.h"
 #include "tunnel_map.h"
+#include "signal_type.h"
 
 
 /**
@@ -122,40 +123,40 @@ static inline TrackBits GetTunnelBridgeReservationTrackBits(TileIndex t)
 }
 
 /**
- * Declare tunnel/bridge with signal simulation.
+ * Declare tunnel/bridge entrance with signal simulation.
  * @param t the tunnel/bridge tile.
  */
-static inline void SetBitTunnelBridgeSignal(TileIndex t)
+static inline void SetTunnelBridgeSignalSimulationEntrance(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
 	SetBit(_m[t].m5, 5);
 }
 
 /**
- * Remove tunnel/bridge with signal simulation.
+ * Remove tunnel/bridge entrance with signal simulation.
  * @param t the tunnel/bridge tile.
  */
-static inline void ClrBitTunnelBridgeSignal(TileIndex t)
+static inline void ClrTunnelBridgeSignalSimulationEntrance(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
 	ClrBit(_m[t].m5, 5);
 }
 
 /**
- * Declare tunnel/bridge exit.
+ * Declare tunnel/bridge exit with signal simulation.
  * @param t the tunnel/bridge tile.
  */
-static inline void SetBitTunnelBridgeExit(TileIndex t)
+static inline void SetTunnelBridgeSignalSimulationExit(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
 	SetBit(_m[t].m5, 6);
 }
 
 /**
- * Remove tunnel/bridge exit declaration.
+ * Remove tunnel/bridge exit with signal simulation.
  * @param t the tunnel/bridge tile.
  */
-static inline void ClrBitTunnelBridgeExit(TileIndex t)
+static inline void ClrTunnelBridgeSignalSimulationExit(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
 	ClrBit(_m[t].m5, 6);
@@ -167,85 +168,81 @@ static inline void ClrBitTunnelBridgeExit(TileIndex t)
  * @param t the tile that might be a tunnel/bridge.
  * @return true if and only if this tile is a tunnel/bridge with signal simulation.
  */
-static inline bool HasWormholeSignals(TileIndex t)
+static inline bool IsTunnelBridgeWithSignalSimulation(TileIndex t)
 {
-	return IsTileType(t, MP_TUNNELBRIDGE) && (HasBit(_m[t].m5, 5) || HasBit(_m[t].m5, 6)) ;
-}
-
-/**
- * Is this a tunnel/bridge with sign on green?
- * @param t the tile that might be a tunnel/bridge with sign set green.
- * @pre IsTileType(t, MP_TUNNELBRIDGE)
- * @return true if and only if this tile is a tunnel/bridge entrance.
- */
-static inline bool IsTunnelBridgeWithSignGreen(TileIndex t)
-{
-	assert(IsTileType(t, MP_TUNNELBRIDGE));
-	return HasBit(_m[t].m5, 5) && !HasBit(_m[t].m5, 6);
-}
-
-static inline bool IsTunnelBridgeWithSignRed(TileIndex t)
-{
-	assert(IsTileType(t, MP_TUNNELBRIDGE));
-	return HasBit(_m[t].m5, 5) && HasBit(_m[t].m5, 6);
+	return IsTileType(t, MP_TUNNELBRIDGE) && (HasBit(_m[t].m5, 5) || HasBit(_m[t].m5, 6));
 }
 
 /**
  * Is this a tunnel/bridge entrance tile with signal?
  * Tunnel bridge signal simulation has allways bit 5 on at entrance.
  * @param t the tile that might be a tunnel/bridge.
+ * @pre IsTileType(t, MP_TUNNELBRIDGE)
  * @return true if and only if this tile is a tunnel/bridge entrance.
  */
-static inline bool IsTunnelBridgeEntrance(TileIndex t)
+static inline bool IsTunnelBridgeSignalSimulationEntrance(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
-	return HasBit(_m[t].m5, 5) ;
+	return HasBit(_m[t].m5, 5) && !HasBit(_m[t].m5, 6);
 }
 
 /**
  * Is this a tunnel/bridge exit?
  * @param t the tile that might be a tunnel/bridge.
+ * @pre IsTileType(t, MP_TUNNELBRIDGE)
  * @return true if and only if this tile is a tunnel/bridge exit.
  */
-static inline bool IsTunnelBridgeExit(TileIndex t)
+static inline bool IsTunnelBridgeSignalSimulationExit(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
 	return !HasBit(_m[t].m5, 5) && HasBit(_m[t].m5, 6);
 }
 
-static inline bool IsTunnelBridgeExitGreen(TileIndex t)
+/**
+ * Get the signal state for a tunnel/bridge entrance or exit with signal simulation
+ * @param t the tunnel/bridge entrance or exit tile with signal simulation
+ * @pre IsTunnelBridgeWithSignalSimulation(t)
+ * @return signal state
+ */
+static inline SignalState GetTunnelBridgeSignalState(TileIndex t)
 {
-	assert(IsTunnelBridgeExit(t));
-	return HasBit(_me[t].m6, 0);
+	assert(IsTunnelBridgeWithSignalSimulation(t));
+	return HasBit(_me[t].m6, 0) ? SIGNAL_STATE_GREEN : SIGNAL_STATE_RED;
 }
 
-static inline void SetTunnelBridgeExitGreen(TileIndex t, bool green)
+/**
+ * Set the signal state for a tunnel/bridge entrance or exit with signal simulation
+ * @param t the tunnel/bridge entrance or exit tile with signal simulation
+ * @pre IsTunnelBridgeWithSignalSimulation(t)
+ * @param state signal state
+ */
+static inline void SetTunnelBridgeSignalState(TileIndex t, SignalState state)
 {
-	assert(IsTunnelBridgeExit(t));
-	SB(_me[t].m6, 0, 1, green ? 1 : 0);
+	assert(IsTunnelBridgeWithSignalSimulation(t));
+	SB(_me[t].m6, 0, 1, (state == SIGNAL_STATE_GREEN) ? 1 : 0);
 }
 
 static inline bool IsTunnelBridgeSemaphore(TileIndex t)
 {
-	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	assert(IsTunnelBridgeWithSignalSimulation(t));
 	return HasBit(_me[t].m6, 1);
 }
 
 static inline void SetTunnelBridgeSemaphore(TileIndex t, bool is_semaphore)
 {
-	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	assert(IsTunnelBridgeWithSignalSimulation(t));
 	SB(_me[t].m6, 1, 1, is_semaphore ? 1 : 0);
 }
 
 static inline bool IsTunnelBridgePBS(TileIndex t)
 {
-	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	assert(IsTunnelBridgeWithSignalSimulation(t));
 	return HasBit(_me[t].m6, 6);
 }
 
 static inline void SetTunnelBridgePBS(TileIndex t, bool is_pbs)
 {
-	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	assert(IsTunnelBridgeWithSignalSimulation(t));
 	SB(_me[t].m6, 6, 1, is_pbs ? 1 : 0);
 }