Enable setting semaphore/electric type of signals on bridges/tunnels.

src/rail_cmd.cpp

@@ -1056,21 +1056,39 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
 		TileIndex tile_exit = GetOtherTunnelBridgeEnd(tile);
 		cost = CommandCost();
+		bool flip_variant = false;
 		if (!HasWormholeSignals(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 {
+			if (HasBit(p1, 17)) return CommandCost();
+			if (ctrl_pressed && !convert_signal) return CommandCost();
+			if ((p2 != 0 && (sigvar == SIG_SEMAPHORE) != IsTunnelBridgeSemaphore(tile)) ||
+					(convert_signal && (ctrl_pressed || (sigvar == SIG_SEMAPHORE) != IsTunnelBridgeSemaphore(tile)))) {
+				flip_variant = true;
+				cost = CommandCost(EXPENSES_CONSTRUCTION, (_price[PR_BUILD_SIGNALS] + _price[PR_CLEAR_SIGNALS]) *
+						((GetTunnelBridgeLength(tile, tile_exit) + 4) >> 2)); // minimal 1
+			}
 		}
 		if (flags & DC_EXEC) {
 			if (p2 == 0 && HasWormholeSignals(tile)) { // Toggle signal if already signals present.
-				if (IsTunnelBridgeEntrance(tile)) {
-					ClrBitTunnelBridgeSignal(tile);
-					ClrBitTunnelBridgeExit(tile_exit);
-					SetBitTunnelBridgeExit(tile);
-					SetBitTunnelBridgeSignal(tile_exit);
+				if (convert_signal) {
+					if (flip_variant) {
+						SetTunnelBridgeSemaphore(tile, !IsTunnelBridgeSemaphore(tile));
+						SetTunnelBridgeSemaphore(tile_exit, !IsTunnelBridgeSemaphore(tile_exit));
+					}
 				} else {
-					ClrBitTunnelBridgeSignal(tile_exit);
-					ClrBitTunnelBridgeExit(tile);
-					SetBitTunnelBridgeExit(tile_exit);
-					SetBitTunnelBridgeSignal(tile);
+					if (IsTunnelBridgeEntrance(tile)) {
+						ClrBitTunnelBridgeSignal(tile);
+						ClrBitTunnelBridgeExit(tile_exit);
+						SetBitTunnelBridgeExit(tile);
+						SetBitTunnelBridgeSignal(tile_exit);
+					} else {
+						ClrBitTunnelBridgeSignal(tile_exit);
+						ClrBitTunnelBridgeExit(tile);
+						SetBitTunnelBridgeExit(tile_exit);
+						SetBitTunnelBridgeSignal(tile);
+					}
 				}
 			} else {
 				/* Create one direction tunnel/bridge if required. */
@@ -1089,6 +1107,8 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 						SetBitTunnelBridgeExit(tile);
 					}
 				}
+				SetTunnelBridgeSemaphore(tile, sigvar == SIG_SEMAPHORE);
+				SetTunnelBridgeSemaphore(tile_exit, sigvar == SIG_SEMAPHORE);
 			}
 			MarkBridgeOrTunnelDirty(tile);
 			AddSideToSignalBuffer(tile, INVALID_DIAGDIR, GetTileOwner(tile));

src/tunnelbridge_cmd.cpp

@@ -1183,7 +1183,7 @@ static void DrawTunnelBridgeRampSignal(const TileInfo *ti)
 	if (ti->tileh == SLOPE_FLAT && side != show_exit && dir == DIAGDIR_SW) z += 2;
 
 	if (ti->tileh != SLOPE_FLAT && IsBridge(ti->tile)) z += 8; // sloped bridge head
-	SignalVariant variant = (_cur_year < _settings_client.gui.semaphore_build_before ? SIG_SEMAPHORE : SIG_ELECTRIC);
+	SignalVariant variant = IsTunnelBridgeSemaphore(ti->tile) ? SIG_SEMAPHORE : SIG_ELECTRIC;
 
 	SpriteID sprite;
 	if (variant == SIG_ELECTRIC) {
@@ -1233,7 +1233,7 @@ static void DrawBrigeSignalOnMiddelPart(const TileInfo *ti, TileIndex bridge_sta
 			uint y = TileY(ti->tile) * TILE_SIZE + SignalPositions[side][position].y;
 			z += 5;
 
-			SignalVariant variant = (_cur_year < _settings_client.gui.semaphore_build_before ? SIG_SEMAPHORE : SIG_ELECTRIC);
+			SignalVariant variant = IsTunnelBridgeSemaphore(bridge_start_tile) ? SIG_SEMAPHORE : SIG_ELECTRIC;
 
 			SpriteID sprite;
 

src/tunnelbridge_map.h

@@ -225,4 +225,16 @@ static inline void SetTunnelBridgeExitGreen(TileIndex t, bool green)
 	SB(_me[t].m6, 0, 1, green ? 1 : 0);
 }
 
+static inline bool IsTunnelBridgeSemaphore(TileIndex t)
+{
+	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	return HasBit(_me[t].m6, 1);
+}
+
+static inline void SetTunnelBridgeSemaphore(TileIndex t, bool is_semaphore)
+{
+	assert(IsTileType(t, MP_TUNNELBRIDGE) && HasWormholeSignals(t));
+	SB(_me[t].m6, 1, 1, is_semaphore ? 1 : 0);
+}
+
 #endif /* TUNNELBRIDGE_MAP_H */