(svn r14919) -Feature: distant joining of stations (Frostregen and PhilSophus)

src/ai/default/default.cpp

@@ -1654,7 +1654,7 @@ static CommandCost AiDoBuildDefaultRailTrack(TileIndex tile, const AiDefaultBloc
 				ret = DoCommand(c, railtype, p->attr, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_TRAIN_DEPOT);
 			} else {
 				// Station
-				ret = DoCommand(c, (p->attr & 1) | (p->attr >> 4) << 8 | (p->attr >> 1 & 7) << 16, railtype, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_RAILROAD_STATION);
+				ret = DoCommand(c, (railtype & 0x0f) | (p->attr & 1) << 4 | (p->attr >> 4) << 8 | (p->attr >> 1 & 7) << 16, (INVALID_STATION << 16), flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_RAILROAD_STATION);
 			}
 
 			if (CmdFailed(ret)) return CMD_ERROR;
@@ -2679,10 +2679,10 @@ static CommandCost AiDoBuildDefaultRoadBlock(TileIndex tile, const AiDefaultBloc
 		} else if (p->mode == 1) {
 			if (_want_road_truck_station) {
 				// Truck station
-				ret = DoCommand(c, p->attr, ROADTYPES_ROAD << 2 | ROADSTOP_TRUCK, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
+				ret = DoCommand(c, p->attr, ROADTYPES_ROAD << 2 | ROADSTOP_TRUCK | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
 			} else {
 				// Bus station
-				ret = DoCommand(c, p->attr, ROADTYPES_ROAD << 2 | ROADSTOP_BUS, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
+				ret = DoCommand(c, p->attr, ROADTYPES_ROAD << 2 | ROADSTOP_BUS | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER | DC_AI_BUILDING, CMD_BUILD_ROAD_STOP);
 			}
 clear_town_stuff:;
 
@@ -3405,7 +3405,7 @@ static CommandCost AiDoBuildDefaultAirportBlock(TileIndex tile, const AiDefaultB
 
 	for (; p->mode == 0; p++) {
 		if (!HasBit(avail_airports, p->attr)) return CMD_ERROR;
-		ret = DoCommand(TILE_MASK(tile + ToTileIndexDiff(p->tileoffs)), p->attr, 0, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_AIRPORT);
+		ret = DoCommand(TILE_MASK(tile + ToTileIndexDiff(p->tileoffs)), p->attr, INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_AIRPORT);
 		if (CmdFailed(ret)) return CMD_ERROR;
 		total_cost.AddCost(ret);
 	}

src/ai/trolly/build.cpp

@@ -43,12 +43,12 @@ bool AiNew_Build_CompanyHQ(Company *c, TileIndex tile)
 CommandCost AiNew_Build_Station(Company *c, byte type, TileIndex tile, byte length, byte numtracks, byte direction, byte flag)
 {
 	if (type == AI_TRAIN)
-		return AI_DoCommand(tile, direction + (numtracks << 8) + (length << 16), 0, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_RAILROAD_STATION);
+		return AI_DoCommand(tile, (direction << 4) + (numtracks << 8) + (length << 16), INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_RAILROAD_STATION);
 
 	if (type == AI_BUS)
-		return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_BUS, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);
+		return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_BUS | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);
 
-	return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_TRUCK, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);
+	return AI_DoCommand(tile, direction, ROADTYPES_ROAD << 2 | ROADSTOP_TRUCK | INVALID_STATION << 16, flag | DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD_STOP);
 }
 
 

src/airport_gui.cpp

@@ -40,7 +40,11 @@ void CcBuildAirport(bool success, TileIndex tile, uint32 p1, uint32 p2)
 
 static void PlaceAirport(TileIndex tile)
 {
-	DoCommandP(tile, _selected_airport_type, _ctrl_pressed, CMD_BUILD_AIRPORT | CMD_MSG(STR_A001_CAN_T_BUILD_AIRPORT_HERE), CcBuildAirport);
+	uint32 p2 = _ctrl_pressed;
+	SB(p2, 16, 16, INVALID_STATION); // no station to join
+
+	CommandContainer cmdcont = { tile, _selected_airport_type, p2, CMD_BUILD_AIRPORT | CMD_MSG(STR_A001_CAN_T_BUILD_AIRPORT_HERE), CcBuildAirport, "" };
+	ShowSelectStationIfNeeded(cmdcont, _thd.size.x / TILE_SIZE, _thd.size.y / TILE_SIZE);
 }
 
 
@@ -124,6 +128,7 @@ struct BuildAirToolbarWindow : Window {
 		this->RaiseButtons();
 
 		delete FindWindowById(WC_BUILD_STATION, 0);
+		delete FindWindowById(WC_SELECT_STATION, 0);
 	}
 };
 
@@ -186,6 +191,11 @@ public:
 		this->FindWindowPlacementAndResize(desc);
 	}
 
+	virtual ~AirportPickerWindow()
+	{
+		DeleteWindowById(WC_SELECT_STATION, 0);
+	}
+
 	virtual void OnPaint()
 	{
 		int i; // airport enabling loop
@@ -247,6 +257,7 @@ public:
 				this->LowerWidget(_selected_airport_type + BAW_SMALL_AIRPORT);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 
 			case BAW_BTN_DONTHILIGHT: case BAW_BTN_DOHILIGHT:

src/command.cpp

@@ -383,7 +383,7 @@ static int _docommand_recursive = 0;
  */
 CommandCost DoCommand(const CommandContainer *container, uint32 flags)
 {
-	return DoCommand(container->tile, container->p1, container->p2, flags, container->cmd, container->text);
+	return DoCommand(container->tile, container->p1, container->p2, flags, container->cmd & CMD_ID_MASK, container->text);
 }
 
 /*!

src/dock_gui.cpp

@@ -47,7 +47,11 @@ void CcBuildCanal(bool success, TileIndex tile, uint32 p1, uint32 p2)
 
 static void PlaceDocks_Dock(TileIndex tile)
 {
-	DoCommandP(tile, _ctrl_pressed, 0, CMD_BUILD_DOCK | CMD_MSG(STR_9802_CAN_T_BUILD_DOCK_HERE), CcBuildDocks);
+	uint32 p2 = INVALID_STATION << 16; // no station to join
+
+	/* tile is always the land tile, so need to evaluate _thd.pos */
+	CommandContainer cmdcont = { tile, _ctrl_pressed, p2, CMD_BUILD_DOCK | CMD_MSG(STR_9802_CAN_T_BUILD_DOCK_HERE), CcBuildDocks, "" };
+	ShowSelectStationIfNeeded(cmdcont, _thd.size.x / TILE_SIZE, _thd.size.y / TILE_SIZE);
 }
 
 static void PlaceDocks_Depot(TileIndex tile)
@@ -240,6 +244,7 @@ struct BuildDocksToolbarWindow : Window {
 
 		delete FindWindowById(WC_BUILD_STATION, 0);
 		delete FindWindowById(WC_BUILD_DEPOT, 0);
+		delete FindWindowById(WC_SELECT_STATION, 0);
 	}
 
 	virtual void OnPlacePresize(Point pt, TileIndex tile_from)
@@ -334,6 +339,11 @@ public:
 		this->FindWindowPlacementAndResize(desc);
 	}
 
+	virtual ~BuildDocksStationWindow()
+	{
+		DeleteWindowById(WC_SELECT_STATION, 0);
+	}
+
 	virtual void OnPaint()
 	{
 		int rad = (_settings_game.station.modified_catchment) ? CA_DOCK : CA_UNMODIFIED;

src/lang/english.txt

@@ -1027,6 +1027,7 @@ STR_CONFIG_PATCHES_MAMMOTHTRAINS                                :{LTBLUE}Enable
 STR_CONFIG_PATCHES_REALISTICACCEL                               :{LTBLUE}Enable realistic acceleration for trains: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_FORBID_90_DEG                                :{LTBLUE}Forbid trains and ships to make 90 deg turns: {ORANGE}{STRING1} {LTBLUE} (not with NTP)
 STR_CONFIG_PATCHES_JOINSTATIONS                                 :{LTBLUE}Join train stations built next to each other: {ORANGE}{STRING1}
+STR_CONFIG_PATCHES_DISTANT_JOIN_STATIONS                        :{LTBLUE}Allow to join stations not directly adjacent: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_IMPROVEDLOAD                                 :{LTBLUE}Use improved loading algorithm: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_GRADUAL_LOADING                              :{LTBLUE}Load vehicles gradually: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_INFLATION                                    :{LTBLUE}Inflation: {ORANGE}{STRING1}
@@ -1721,6 +1722,8 @@ STR_RAILROAD_TRACK_WITH_COMBO_PBSSIGNALS                        :Railway track w
 STR_RAILROAD_TRACK_WITH_COMBO_NOENTRYSIGNALS                    :Railway track with combo- and one-way path signals
 STR_RAILROAD_TRACK_WITH_PBS_NOENTRYSIGNALS                      :Railway track with path and one-way path signals
 STR_MUST_REMOVE_RAILWAY_STATION_FIRST                           :{WHITE}Must remove railway station first
+STR_CREATE_SPLITTED_STATION                                     :{YELLOW}Build a separate station
+STR_SELECT_STATION_TO_JOIN                                      :{BLACK}Join station
 
 
 

src/rail_gui.cpp

@@ -188,10 +188,15 @@ static void PlaceRail_Station(TileIndex tile)
 		VpStartPlaceSizing(tile, VPM_X_AND_Y_LIMITED, DDSP_BUILD_STATION);
 		VpSetPlaceSizingLimit(_settings_game.station.station_spread);
 	} else {
-		DoCommandP(tile,
-				_railstation.orientation | (_settings_client.gui.station_numtracks << 8) | (_settings_client.gui.station_platlength << 16) | (_ctrl_pressed << 24),
-				_cur_railtype | (_railstation.station_class << 8) | (_railstation.station_type << 16),
-				CMD_BUILD_RAILROAD_STATION | CMD_MSG(STR_100F_CAN_T_BUILD_RAILROAD_STATION), CcStation);
+		uint32 p1 = _cur_railtype | _railstation.orientation << 4 | _settings_client.gui.station_numtracks << 8 | _settings_client.gui.station_platlength << 16 | _ctrl_pressed << 24;
+		uint32 p2 = _railstation.station_class | _railstation.station_type << 8 | INVALID_STATION << 16;
+
+		int w = _settings_client.gui.station_numtracks;
+		int h = _settings_client.gui.station_platlength;
+		if (!_railstation.orientation) Swap(w, h);
+
+		CommandContainer cmdcont = { tile, p1, p2, CMD_BUILD_RAILROAD_STATION | CMD_MSG(STR_100F_CAN_T_BUILD_RAILROAD_STATION), CcStation, "" };
+		ShowSelectStationIfNeeded(cmdcont, w, h);
 	}
 }
 
@@ -753,6 +758,7 @@ struct BuildRailToolbarWindow : Window {
 		delete FindWindowById(WC_BUILD_SIGNAL, 0);
 		delete FindWindowById(WC_BUILD_STATION, 0);
 		delete FindWindowById(WC_BUILD_DEPOT, 0);
+		delete FindWindowById(WC_SELECT_STATION, 0);
 	}
 
 	virtual void OnPlacePresize(Point pt, TileIndex tile)
@@ -873,12 +879,13 @@ static void HandleStationPlacement(TileIndex start, TileIndex end)
 	if (sy > ey) Swap(sy, ey);
 	w = ex - sx + 1;
 	h = ey - sy + 1;
+
 	if (_railstation.orientation == AXIS_X) Swap(w, h);
+	uint32 p1 = _cur_railtype | _railstation.orientation << 4 | _ctrl_pressed << 24;
+	uint32 p2 = _railstation.station_class | _railstation.station_type << 8 | INVALID_STATION << 16;
 
-	DoCommandP(TileXY(sx, sy),
-			_railstation.orientation | (w << 8) | (h << 16) | (_ctrl_pressed << 24),
-			_cur_railtype | (_railstation.station_class << 8) | (_railstation.station_type << 16),
-			CMD_BUILD_RAILROAD_STATION | CMD_MSG(STR_100F_CAN_T_BUILD_RAILROAD_STATION), CcStation);
+	CommandContainer cmdcont = { TileXY(sx, sy), p1 | w << 8 | h << 16, p2, CMD_BUILD_RAILROAD_STATION | CMD_MSG(STR_100F_CAN_T_BUILD_RAILROAD_STATION), CcStation, "" };
+	ShowSelectStationIfNeeded(cmdcont, w, h);
 }
 
 struct BuildRailStationWindow : public PickerWindowBase {
@@ -993,6 +1000,11 @@ public:
 		}
 	}
 
+	virtual ~BuildRailStationWindow()
+	{
+		DeleteWindowById(WC_SELECT_STATION, 0);
+	}
+
 	virtual void OnPaint()
 	{
 		bool newstations = _railstation.newstations;
@@ -1094,6 +1106,7 @@ public:
 				this->LowerWidget(_railstation.orientation + BRSW_PLATFORM_DIR_X);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 
 			case BRSW_PLATFORM_NUM_1:
@@ -1127,6 +1140,7 @@ public:
 				this->LowerWidget(_settings_client.gui.station_platlength + BRSW_PLATFORM_LEN_BEGIN);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 			}
 
@@ -1161,6 +1175,7 @@ public:
 				this->LowerWidget(_settings_client.gui.station_platlength + BRSW_PLATFORM_LEN_BEGIN);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 			}
 
@@ -1194,6 +1209,7 @@ public:
 				this->SetWidgetLoweredState(_settings_client.gui.station_platlength + BRSW_PLATFORM_LEN_BEGIN, !_settings_client.gui.station_dragdrop);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 			} break;
 
 			case BRSW_HIGHLIGHT_OFF:
@@ -1230,6 +1246,7 @@ public:
 
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 			}
 		}
@@ -1250,6 +1267,7 @@ public:
 
 		SndPlayFx(SND_15_BEEP);
 		this->SetDirty();
+		DeleteWindowById(WC_SELECT_STATION, 0);
 	}
 
 	virtual void OnTick()

src/road_gui.cpp

@@ -206,12 +206,14 @@ static void PlaceRoad_Depot(TileIndex tile)
 static void PlaceRoadStop(TileIndex tile, uint32 p2, uint32 cmd)
 {
 	uint32 p1 = _road_station_picker_orientation;
+	SB(p2, 16, 16, INVALID_STATION); // no station to join
 
 	if (p1 >= DIAGDIR_END) {
 		SetBit(p2, 1); // It's a drive-through stop
 		p1 -= DIAGDIR_END; // Adjust picker result to actual direction
 	}
-	DoCommandP(tile, p1, p2, cmd, CcRoadDepot);
+	CommandContainer cmdcont = { tile, p1, p2, cmd, CcRoadDepot, "" };
+	ShowSelectStationIfNeeded(cmdcont, 1, 1);
 }
 
 static void PlaceRoad_BusStation(TileIndex tile)
@@ -528,6 +530,7 @@ struct BuildRoadToolbarWindow : Window {
 		delete FindWindowById(WC_BUS_STATION, 0);
 		delete FindWindowById(WC_TRUCK_STATION, 0);
 		delete FindWindowById(WC_BUILD_DEPOT, 0);
+		delete FindWindowById(WC_SELECT_STATION, 0);
 	}
 
 	virtual void OnPlaceDrag(ViewportPlaceMethod select_method, ViewportDragDropSelectionProcess select_proc, Point pt)
@@ -835,6 +838,11 @@ public:
 		this->FindWindowPlacementAndResize(desc);
 	}
 
+	virtual ~BuildRoadStationWindow()
+	{
+		DeleteWindowById(WC_SELECT_STATION, 0);
+	}
+
 	virtual void OnPaint()
 	{
 		this->DrawWidgets();
@@ -883,6 +891,7 @@ public:
 				this->LowerWidget(_road_station_picker_orientation + BRSW_STATION_NE);
 				SndPlayFx(SND_15_BEEP);
 				this->SetDirty();
+				DeleteWindowById(WC_SELECT_STATION, 0);
 				break;
 
 			case BRSW_LT_OFF:

src/saveload/saveload.cpp

@@ -42,7 +42,7 @@
 
 #include <list>
 
-extern const uint16 SAVEGAME_VERSION = 105;
+extern const uint16 SAVEGAME_VERSION = 106;
 
 SavegameType _savegame_type; ///< type of savegame we are loading
 

src/settings.cpp

@@ -1309,6 +1309,7 @@ const SettingDesc _patch_settings[] = {
 	SDT_CONDBOOL(GameSettings, construction.road_stop_on_town_road,             47, SL_MAX_VERSION, 0, 0,  true,                    STR_CONFIG_PATCHES_STOP_ON_TOWN_ROAD,      NULL),
 	SDT_CONDBOOL(GameSettings, station.adjacent_stations,                       62, SL_MAX_VERSION, 0, 0,  true,                    STR_CONFIG_PATCHES_ADJACENT_STATIONS,      NULL),
 	SDT_CONDBOOL(GameSettings, economy.station_noise_level,                     96, SL_MAX_VERSION, 0, 0, false,                    STR_CONFIG_PATCHES_NOISE_LEVEL,            InvalidateTownViewWindow),
+	SDT_CONDBOOL(GameSettings, station.distant_join_stations,                  106, SL_MAX_VERSION, 0, 0,  true,                    STR_CONFIG_PATCHES_DISTANT_JOIN_STATIONS,  NULL),
 
 	    SDT_BOOL(GameSettings, economy.inflation,                                                   0, 0,  true,                    STR_CONFIG_PATCHES_INFLATION,              NULL),
 	     SDT_VAR(GameSettings, construction.raw_industry_construction, SLE_UINT8,                   0,MS,     0,     0,       2, 0, STR_CONFIG_PATCHES_RAW_INDUSTRY_CONSTRUCTION_METHOD, InvalidateBuildIndustryWindow),

src/settings_gui.cpp

@@ -671,6 +671,7 @@ static const char *_patches_stations[] = {
 	"order.gradual_loading",
 	"construction.road_stop_on_town_road",
 	"station.adjacent_stations",
+	"station.distant_join_stations",
 	"economy.station_noise_level",
 };
 

src/settings_type.h

@@ -328,6 +328,7 @@ struct StationSettings {
 	bool   join_stations;                    ///< allow joining of train stations
 	bool   nonuniform_stations;              ///< allow nonuniform train stations
 	bool   adjacent_stations;                ///< allow stations to be built directly adjacent to other stations
+	bool   distant_join_stations;            ///< allow to join non-adjacent stations
 	bool   always_small_airport;             ///< always allow small airports
 	byte   station_spread;                   ///< amount a station may spread
 };

src/station.cpp

@@ -104,6 +104,8 @@ Station::~Station()
 
 	xy = INVALID_TILE;
 
+	InvalidateWindowData(WC_SELECT_STATION, 0, 0);
+
 	for (CargoID c = 0; c < NUM_CARGO; c++) {
 		goods[c].cargo.Truncate(0);
 	}

src/station_cmd.cpp

@@ -908,23 +908,24 @@ static void GetStationLayout(byte *layout, int numtracks, int plat_len, const St
  * @param tile_org starting position of station dragging/placement
  * @param flags operation to perform
  * @param p1 various bitstuffed elements
- * - p1 = (bit  0)    - orientation (Axis)
+ * - p1 = (bit  0- 3) - railtype (p1 & 0xF)
+ * - p1 = (bit  4)    - orientation (Axis)
  * - p1 = (bit  8-15) - number of tracks
  * - p1 = (bit 16-23) - platform length
  * - p1 = (bit 24)    - allow stations directly adjacent to other stations.
  * @param p2 various bitstuffed elements
- * - p2 = (bit  0- 3) - railtype (p2 & 0xF)
- * - p2 = (bit  8-15) - custom station class
- * - p2 = (bit 16-23) - custom station id
+ * - p2 = (bit  0- 7) - custom station class
+ * - p2 = (bit  8-15) - custom station id
+ * - p2 = (bit 16-31) - station ID to join (INVALID_STATION if build new one)
  */
 CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1, uint32 p2, const char *text)
 {
 	/* Does the authority allow this? */
 	if (!(flags & DC_NO_TOWN_RATING) && !CheckIfAuthorityAllows(tile_org)) return CMD_ERROR;
-	if (!ValParamRailtype((RailType)(p2 & 0xF))) return CMD_ERROR;
+	if (!ValParamRailtype((RailType)(p1 & 0xF))) return CMD_ERROR;
 
 	/* unpack parameters */
-	Axis axis = Extract<Axis, 0>(p1);
+	Axis axis = Extract<Axis, 4>(p1);
 	uint numtracks = GB(p1,  8, 8);
 	uint plat_len  = GB(p1, 16, 8);
 
@@ -937,6 +938,11 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 		w_org = numtracks;
 	}
 
+	StationID station_to_join = GB(p2, 16, 16);
+	bool distant_join = (station_to_join != INVALID_STATION);
+
+	if (distant_join && (!_settings_game.station.distant_join_stations || !IsValidStationID(station_to_join))) return CMD_ERROR;
+
 	if (h_org > _settings_game.station.station_spread || w_org > _settings_game.station.station_spread) return CMD_ERROR;
 
 	/* these values are those that will be stored in train_tile and station_platforms */
@@ -959,7 +965,7 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 
 	if (_settings_game.station.adjacent_stations) {
 		if (est != INVALID_STATION) {
-			if (HasBit(p1, 24)) {
+			if (HasBit(p1, 24) && est != station_to_join) {
 				/* You can't build an adjacent station over the top of one that
 				 * already exists. */
 				return_cmd_error(STR_MUST_REMOVE_RAILWAY_STATION_FIRST);
@@ -982,6 +988,9 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 		if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
 	}
 
+	/* Distant join */
+	if (st == NULL && distant_join) st = GetStation(station_to_join);
+
 	/* See if there is a deleted station close to us. */
 	if (st == NULL) st = GetClosestDeletedStation(tile_org);
 
@@ -1017,10 +1026,10 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 	}
 
 	/* Check if the given station class is valid */
-	if (GB(p2, 8, 8) >= GetNumStationClasses()) return CMD_ERROR;
+	if (GB(p2, 0, 8) >= GetNumStationClasses()) return CMD_ERROR;
 
 	/* Check if we can allocate a custom stationspec to this station */
-	const StationSpec *statspec = GetCustomStationSpec((StationClassID)GB(p2, 8, 8), GB(p2, 16, 8));
+	const StationSpec *statspec = GetCustomStationSpec((StationClassID)GB(p2, 0, 8), GB(p2, 8, 8));
 	int specindex = AllocateSpecToStation(statspec, st, flags & DC_EXEC);
 	if (specindex == -1) return CMD_ERROR;
 
@@ -1090,7 +1099,7 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 					}
 				}
 
-				MakeRailStation(tile, st->owner, st->index, axis, layout & ~1, (RailType)GB(p2, 0, 4));
+				MakeRailStation(tile, st->owner, st->index, axis, layout & ~1, (RailType)GB(p1, 0, 4));
 				SetCustomStationSpecIndex(tile, specindex);
 				SetStationTileRandomBits(tile, GB(Random(), 0, 4));
 				SetStationAnimationFrame(tile, 0);
@@ -1126,6 +1135,7 @@ CommandCost CmdBuildRailroadStation(TileIndex tile_org, uint32 flags, uint32 p1,
 		st->MarkTilesDirty(false);
 		UpdateStationVirtCoordDirty(st);
 		UpdateStationAcceptance(st, false);
+		InvalidateWindowData(WC_SELECT_STATION, 0, 0);
 		InvalidateWindowData(WC_STATION_LIST, st->owner, 0);
 		InvalidateWindowWidget(WC_STATION_VIEW, st->index, SVW_TRAINS);
 	}
@@ -1397,6 +1407,7 @@ static RoadStop **FindRoadStopSpot(bool truck_station, Station *st)
  *           bit 1: 0 for normal, 1 for drive-through
  *           bit 2..4: the roadtypes
  *           bit 5: allow stations directly adjacent to other stations.
+ *           bit 16..31: station ID to join (INVALID_STATION if build new one)
  */
 CommandCost CmdBuildRoadStop(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, const char *text)
 {
@@ -1405,6 +1416,10 @@ CommandCost CmdBuildRoadStop(TileIndex tile, uint32 flags, uint32 p1, uint32 p2,
 	bool build_over_road  = is_drive_through && IsNormalRoadTile(tile);
 	bool town_owned_road  = false;
 	RoadTypes rts = (RoadTypes)GB(p2, 2, 3);
+	StationID station_to_join = GB(p2, 16, 16);
+	bool distant_join = (station_to_join != INVALID_STATION);
+
+	if (distant_join && (!_settings_game.station.distant_join_stations || !IsValidStationID(station_to_join))) return CMD_ERROR;
 
 	if (!AreValidRoadTypes(rts) || !HasRoadTypesAvail(_current_company, rts)) return CMD_ERROR;
 
@@ -1462,6 +1477,9 @@ CommandCost CmdBuildRoadStop(TileIndex tile, uint32 flags, uint32 p1, uint32 p2,
 		if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
 	}
 
+	/* Distant join */
+	if (st == NULL && distant_join) st = GetStation(station_to_join);
+
 	/* Find a deleted station close to us */
 	if (st == NULL) st = GetClosestDeletedStation(tile);
 
@@ -1518,6 +1536,7 @@ CommandCost CmdBuildRoadStop(TileIndex tile, uint32 flags, uint32 p1, uint32 p2,
 
 		UpdateStationVirtCoordDirty(st);
 		UpdateStationAcceptance(st, false);
+		InvalidateWindowData(WC_SELECT_STATION, 0, 0);
 		InvalidateWindowData(WC_STATION_LIST, st->owner, 0);
 		InvalidateWindowWidget(WC_STATION_VIEW, st->index, SVW_ROADVEHS);
 	}
@@ -1818,11 +1837,17 @@ void UpdateAirportsNoise()
  * @param tile tile where airport will be built
  * @param flags operation to perform
  * @param p1 airport type, @see airport.h
- * @param p2 (bit 0) - allow airports directly adjacent to other airports.
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit     0) - allow airports directly adjacent to other airports.
+ * - p2 = (bit 16-31) - station ID to join (INVALID_STATION if build new one)
  */
 CommandCost CmdBuildAirport(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, const char *text)
 {
 	bool airport_upgrade = true;
+	StationID station_to_join = GB(p2, 16, 16);
+	bool distant_join = (station_to_join != INVALID_STATION);
+
+	if (distant_join && (!_settings_game.station.distant_join_stations || !IsValidStationID(station_to_join))) return CMD_ERROR;
 
 	/* Check if a valid, buildable airport was chosen for construction */
 	if (p1 > lengthof(_airport_sections) || !HasBit(GetValidAirports(), p1)) return CMD_ERROR;
@@ -1875,6 +1900,9 @@ CommandCost CmdBuildAirport(TileIndex tile, uint32 flags, uint32 p1, uint32 p2,
 		st = NULL;
 	}
 
+	/* Distant join */
+	if (st == NULL && distant_join) st = GetStation(station_to_join);
+
 	/* Find a deleted station close to us */
 	if (st == NULL) st = GetClosestDeletedStation(tile);
 
@@ -1940,6 +1968,7 @@ CommandCost CmdBuildAirport(TileIndex tile, uint32 flags, uint32 p1, uint32 p2,
 
 		UpdateStationVirtCoordDirty(st);
 		UpdateStationAcceptance(st, false);
+		InvalidateWindowData(WC_SELECT_STATION, 0, 0);
 		InvalidateWindowData(WC_STATION_LIST, st->owner, 0);
 		InvalidateWindowWidget(WC_STATION_VIEW, st->index, SVW_PLANES);
 
@@ -2125,10 +2154,15 @@ static const byte _dock_h_chk[4] = { 1, 2, 1, 2 };
  * @param tile tile where dock will be built
  * @param flags operation to perform
  * @param p1 (bit 0) - allow docks directly adjacent to other docks.
- * @param p2 unused
+ * @param p2 bit 16-31: station ID to join (INVALID_STATION if build new one)
  */
 CommandCost CmdBuildDock(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, const char *text)
 {
+	StationID station_to_join = GB(p2, 16, 16);
+	bool distant_join = (station_to_join != INVALID_STATION);
+
+	if (distant_join && (!_settings_game.station.distant_join_stations || !IsValidStationID(station_to_join))) return CMD_ERROR;
+
 	DiagDirection direction = GetInclinedSlopeDirection(GetTileSlope(tile, NULL));
 	if (direction == INVALID_DIAGDIR) return_cmd_error(STR_304B_SITE_UNSUITABLE);
 	direction = ReverseDiagDir(direction);
@@ -2170,6 +2204,9 @@ CommandCost CmdBuildDock(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, con
 		if (st == CHECK_STATIONS_ERR) return CMD_ERROR;
 	}
 
+	/* Distant join */
+	if (st == NULL && distant_join) st = GetStation(station_to_join);
+
 	/* Find a deleted station close to us */
 	if (st == NULL) st = GetClosestDeletedStation(tile);
 
@@ -2212,6 +2249,7 @@ CommandCost CmdBuildDock(TileIndex tile, uint32 flags, uint32 p1, uint32 p2, con
 
 		UpdateStationVirtCoordDirty(st);
 		UpdateStationAcceptance(st, false);
+		InvalidateWindowData(WC_SELECT_STATION, 0, 0);
 		InvalidateWindowData(WC_STATION_LIST, st->owner, 0);
 		InvalidateWindowWidget(WC_STATION_VIEW, st->index, SVW_SHIPS);
 	}

src/station_gui.cpp

@@ -25,6 +25,13 @@
 #include "gfx_func.h"
 #include "widgets/dropdown_func.h"
 #include "newgrf_cargo.h"
+#include "map_func.h"
+#include "settings_type.h"
+#include "tile_map.h"
+#include "station_map.h"
+#include "tilehighlight_func.h"
+#include "core/smallvec_type.hpp"
+#include "core/smallmap_type.hpp"
 #include "string_func.h"
 #include "company_base.h"
 #include "sortlist_type.h"
@@ -974,3 +981,266 @@ void ShowStationViewWindow(StationID station)
 {
 	AllocateWindowDescFront<StationViewWindow>(&_station_view_desc, station);
 }
+
+static SmallVector<StationID, 8> _stations_nearby_list;
+static SmallMap<TileIndex, StationID, 8> _deleted_stations_nearby;
+
+/** Context for FindStationsNearby */
+struct FindNearbyStationContext {
+	TileIndex tile; ///< Base tile of station to be built
+	uint      w;    ///< Width of station to be built
+	uint      h;    ///< Height of station to be built
+};
+
+/**
+ * Add station on this tile to _stations_nearby_list if it's fully within the
+ * station spread.
+ * @param tile Tile just being checked
+ * @param user_data Pointer to FindNearbyStationContext context
+ */
+static bool AddNearbyStation(TileIndex tile, void *user_data)
+{
+	FindNearbyStationContext *ctx = (FindNearbyStationContext *)user_data;
+
+	/* First check if there was a deleted station here */
+	SmallPair<TileIndex, StationID> *dst = _deleted_stations_nearby.Find(tile);
+	if (dst != _deleted_stations_nearby.End()) {
+		_stations_nearby_list.Include(dst->second);
+		return false;
+	}
+
+	/* Check if own station and if we stay within station spread */
+	if (!IsTileType(tile, MP_STATION)) return false;
+
+	StationID sid = GetStationIndex(tile);
+	Station *st = GetStation(sid);
+	if (st->owner != _local_company || _stations_nearby_list.Contains(sid)) return false;
+
+	if (st->rect.BeforeAddRect(ctx->tile, ctx->w, ctx->h, StationRect::ADD_TEST)) {
+		*_stations_nearby_list.Append() = sid;
+	}
+
+	return false; // We want to include *all* nearby stations
+}
+
+/**
+ * Circulate around the to-be-built station to find stations we could join.
+ * Make sure that only stations are returned where joining wouldn't exceed
+ * station spread and are our own station.
+ * @param tile Base tile of the to-be-built station
+ * @param w Width of the to-be-built station
+ * @param h Height of the to-be-built station
+ * @param distant_join Search for adjacent stations (false) or stations fully
+ *                     within station spread
+ **/
+static const Station *FindStationsNearby(TileIndex tile, int w, int h, bool distant_join)
+{
+	FindNearbyStationContext ctx;
+	ctx.tile = tile;
+	ctx.w = w;
+	ctx.h = h;
+
+	_stations_nearby_list.Clear();
+	_deleted_stations_nearby.Clear();
+
+	/* Check the inside, to return, if we sit on another station */
+	BEGIN_TILE_LOOP(t, w, h, tile)
+		if (t < MapSize() && IsTileType(t, MP_STATION)) return GetStationByTile(t);
+	END_TILE_LOOP(t, w, h, tile)
+
+	/* Look for deleted stations */
+	const Station *st;
+	FOR_ALL_STATIONS(st) {
+		if (st->facilities == 0 && st->owner == _local_company) {
+			/* Include only within station spread (yes, it is strictly less than) */
+			if (max(DistanceMax(tile, st->xy), DistanceMax(TILE_ADDXY(tile, w - 1, h - 1), st->xy)) < _settings_game.station.station_spread) {
+				_deleted_stations_nearby.Insert(st->xy, st->index);
+
+				/* Add the station when it's within where we're going to build */
+				if (IsInsideBS(TileX(st->xy), TileX(ctx.tile), ctx.w) &&
+						IsInsideBS(TileY(st->xy), TileY(ctx.tile), ctx.h)) {
+					AddNearbyStation(st->xy, &ctx);
+				}
+			}
+		}
+	}
+
+	/* Only search tiles where we have a chance to stay within the station spread.
+	 * The complete check needs to be done in the callback as we don't know the
+	 * extent of the found station, yet. */
+	if (distant_join && min(w, h) >= _settings_game.station.station_spread) return NULL;
+	uint max_dist = distant_join ? _settings_game.station.station_spread - min(w, h) : 1;
+
+	tile = TILE_ADD(ctx.tile, TileOffsByDir(DIR_N));
+	CircularTileSearch(&tile, max_dist, w, h, AddNearbyStation, &ctx);
+
+	return NULL;
+}
+
+enum JoinStationWidgets {
+	JSW_WIDGET_CLOSEBOX = 0,
+	JSW_WIDGET_CAPTION,
+	JSW_PANEL,
+	JSW_SCROLLBAR,
+	JSW_EMPTY,
+	JSW_RESIZEBOX,
+};
+
+static const Widget _select_station_widgets[] = {
+{   WWT_CLOSEBOX,   RESIZE_NONE, COLOUR_DARK_GREEN,     0,    10,     0,    13, STR_00C5,                        STR_018B_CLOSE_WINDOW},
+{    WWT_CAPTION,  RESIZE_RIGHT, COLOUR_DARK_GREEN,    11,   199,     0,    13, STR_SELECT_STATION_TO_JOIN,      STR_018C_WINDOW_TITLE_DRAG_THIS},
+{      WWT_PANEL,     RESIZE_RB, COLOUR_DARK_GREEN,     0,   187,    14,    79, 0x0,                             STR_NULL},
+{  WWT_SCROLLBAR,    RESIZE_LRB, COLOUR_DARK_GREEN,   188,   199,    14,    79, 0x0,                             STR_0190_SCROLL_BAR_SCROLLS_LIST},
+{      WWT_PANEL,    RESIZE_RTB, COLOUR_DARK_GREEN,     0,   187,    80,    91, 0x0,                             STR_NULL},
+{  WWT_RESIZEBOX,   RESIZE_LRTB, COLOUR_DARK_GREEN,   188,   199,    80,    91, 0x0,                             STR_RESIZE_BUTTON},
+{   WIDGETS_END},
+};
+
+struct SelectStationWindow : Window {
+	CommandContainer select_station_cmd; ///< Command to build new station
+	TileIndex tile; ///< Base tile of new station
+	int size_x;     ///< Size in x direction of new station
+	int size_y;     ///< Size in y direction of new station
+
+	SelectStationWindow(const WindowDesc *desc, CommandContainer cmd) :
+		Window(desc, 0),
+		select_station_cmd(cmd),
+		tile(TileVirtXY(_thd.pos.x, _thd.pos.y)),
+		size_x(_thd.size.x / TILE_SIZE),
+		size_y(_thd.size.y / TILE_SIZE)
+	{
+		this->vscroll.cap = 6;
+		this->resize.step_height = 10;
+		_thd.lock_pos = true;
+		_thd.lock_size = true;
+
+		FindStationsNearby(this->tile, this->size_x, this->size_y, true);
+
+		this->FindWindowPlacementAndResize(desc);
+	}
+
+	~SelectStationWindow()
+	{
+		_thd.lock_pos = false;
+		_thd.lock_size = false;
+	}
+
+	virtual void OnPaint()
+	{
+		SetVScrollCount(this, _stations_nearby_list.Length() + 1);
+
+		this->DrawWidgets();
+
+		uint y = 17;
+		if (this->vscroll.pos == 0) {
+			DrawStringTruncated(3, y, STR_CREATE_SPLITTED_STATION, TC_FROMSTRING, this->widget[JSW_PANEL].right - 5);
+			y += 10;
+		}
+
+		for (uint i = max<uint>(1, this->vscroll.pos); i <= _stations_nearby_list.Length(); ++i, y += 10) {
+			/* Don't draw anything if it extends past the end of the window. */
+			if (i - this->vscroll.pos >= this->vscroll.cap) break;
+
+			const Station *st = GetStation(_stations_nearby_list[i - 1]);
+			SetDParam(0, st->index);
+			SetDParam(1, st->facilities);
+			DrawStringTruncated(3, y, STR_3049_0, TC_FROMSTRING, this->widget[JSW_PANEL].right - 5);
+		}
+	}
+
+	virtual void OnClick(Point pt, int widget)
+	{
+		if (widget != JSW_PANEL) return;
+
+		uint32 st_index = (pt.y - 16) / 10 + this->vscroll.pos;
+		bool distant_join = (st_index > 0);
+		if (distant_join) st_index--;
+
+		if (distant_join && st_index >= _stations_nearby_list.Length()) return;
+
+		/* Insert station to be joined into stored command */
+		SB(this->select_station_cmd.p2, 16, 16,
+		   (distant_join ? _stations_nearby_list[st_index] : INVALID_STATION));
+
+		/* Execute stored Command */
+		DoCommandP(&this->select_station_cmd);
+
+		/* Close Window; this might cause double frees! */
+		DeleteWindowById(WC_SELECT_STATION, 0);
+	}
+
+	virtual void OnTick()
+	{
+		if (_thd.dirty & 2) {
+			_thd.dirty &= ~2;
+			this->SetDirty();
+		}
+	}
+
+	virtual void OnResize(Point new_size, Point delta)
+	{
+		this->vscroll.cap = (this->widget[JSW_PANEL].bottom - this->widget[JSW_PANEL].top) / 10;
+	}
+
+	virtual void OnInvalidateData(int data)
+	{
+		FindStationsNearby(this->tile, this->size_x, this->size_y, true);
+		this->SetDirty();
+	}
+};
+
+static const WindowDesc _select_station_desc = {
+	WDP_AUTO, WDP_AUTO, 200, 92, 200, 182,
+	WC_SELECT_STATION, WC_NONE,
+	WDF_STD_TOOLTIPS | WDF_STD_BTN | WDF_DEF_WIDGET | WDF_RESIZABLE,
+	_select_station_widgets,
+};
+
+
+/**
+ * Check whether we need to show the station selection window.
+ * @param cmd Command to build the station.
+ * @param w Width of the to-be-built station
+ * @param h Height of the to-be-built station
+ * @return whether we need to show the station selection window.
+ */
+static bool StationJoinerNeeded(CommandContainer cmd, int w, int h)
+{
+	if (CmdFailed(DoCommand(&cmd, DC_NO_WATER | DC_AUTO))) return false;
+
+	/* Only show selection if distant join is enabled in the settings */
+	if (!_settings_game.station.distant_join_stations) return false;
+
+	/* If a window is already opened, we always return true */
+	if (FindWindowById(WC_SELECT_STATION, 0) != NULL) return true;
+
+	/* only show the popup, if we press ctrl */
+	if (!_ctrl_pressed) return false;
+
+	/* First test for adjacent station */
+	FindStationsNearby(cmd.tile, w, h, false);
+	int neighbour_station_count = _stations_nearby_list.Length();
+	/* Now test for stations fully within station spread */
+	const Station *st = FindStationsNearby(cmd.tile, w, h, true);
+	if (_settings_game.station.adjacent_stations) {
+		return (neighbour_station_count == 0 || _stations_nearby_list.Length() > 1) && st == NULL;
+	} else {
+		return neighbour_station_count == 0 && _stations_nearby_list.Length() > 0 && st == NULL;
+	}
+}
+
+/**
+ * Show the station selection window when needed. If not, build the station.
+ * @param cmd Command to build the station.
+ * @param w Width of the to-be-built station
+ * @param h Height of the to-be-built station
+ */
+void ShowSelectStationIfNeeded(CommandContainer cmd, int w, int h)
+{
+	if (StationJoinerNeeded(cmd, w, h)) {
+		if (BringWindowToFrontById(WC_SELECT_STATION, 0)) return;
+		new SelectStationWindow(&_select_station_desc, cmd);
+	} else {
+		DoCommandP(&cmd);
+	}
+}

src/station_gui.h

@@ -5,6 +5,8 @@
 #ifndef STATION_GUI_H
 #define STATION_GUI_H
 
+#include "command_type.h"
+
 /** Enum for CompanyStations, referring to _company_stations_widgets */
 enum StationListWidgets {
 	SLW_CLOSEBOX       =  0, ///< Close 'X' button
@@ -57,4 +59,6 @@ enum StationCoverageType {
 int DrawStationCoverageAreaText(int sx, int sy, StationCoverageType sct, int rad, bool supplies);
 void CheckRedrawStationCoverage(const Window *w);
 
+void ShowSelectStationIfNeeded(CommandContainer cmd, int w, int h);
+
 #endif /* STATION_GUI_H */

src/tilehighlight_type.h

@@ -71,6 +71,9 @@ struct TileHighlightData {
 	ViewportPlaceMethod select_method;
 	ViewportDragDropSelectionProcess select_proc;
 
+	bool lock_pos;  //< If position changes are taken, or not
+	bool lock_size; //< If size changes are taken, or not
+
 	TileIndex redsq;
 };
 

src/viewport.cpp

@@ -2175,11 +2175,17 @@ void UpdateTileSelection()
 		/* clear the old selection? */
 		if (_thd.drawstyle) SetSelectionTilesDirty();
 
-		_thd.drawstyle = _thd.new_drawstyle;
-		_thd.pos = _thd.new_pos;
-		_thd.size = _thd.new_size;
+		if (!_thd.lock_pos) {
+			_thd.pos = _thd.new_pos;
+			_thd.drawstyle = _thd.new_drawstyle;
+		}
+
+		if (!_thd.lock_size) {
+			_thd.size = _thd.new_size;
+			_thd.dirty = 0xff;
+		}
+
 		_thd.outersize = _thd.new_outersize;
-		_thd.dirty = 0xff;
 
 		/* draw the new selection? */
 		if (_thd.new_drawstyle) SetSelectionTilesDirty();
@@ -2619,7 +2625,7 @@ calc_heightdiff_single_direction:;
 			y = sy + Clamp(y - sy, -limit, limit);
 			} /* Fallthrough */
 		case VPM_X_AND_Y: { /* drag an X by Y area */
-			if (_settings_client.gui.measure_tooltip) {
+			if (_settings_client.gui.measure_tooltip && !_thd.lock_size) {
 				static const StringID measure_strings_area[] = {
 					STR_NULL, STR_NULL, STR_MEASURE_AREA, STR_MEASURE_AREA_HEIGHTDIFF
 				};
@@ -2713,6 +2719,10 @@ void SetObjectToPlaceWnd(CursorID icon, SpriteID pal, ViewportHighlightMode mode
 
 void SetObjectToPlace(CursorID icon, SpriteID pal, ViewportHighlightMode mode, WindowClass window_class, WindowNumber window_num)
 {
+	/* unlock position and size */
+	_thd.lock_pos = false;
+	_thd.lock_size = false;
+
 	/* undo clicking on button and drag & drop */
 	if (_thd.place_mode != VHM_NONE || _special_mouse_mode == WSM_DRAGDROP) {
 		Window *w = FindWindowById(_thd.window_class, _thd.window_number);

src/window_type.h

@@ -95,6 +95,7 @@ enum WindowClass {
 	WC_COMPANY_PASSWORD_WINDOW,
 	WC_OSK,
 	WC_WAYPOINT_VIEW,
+	WC_SELECT_STATION,
 
 	WC_INVALID = 0xFFFF
 };