Add: Add and adapt some functions for extended depots.

src/depot.cpp

@@ -112,19 +112,29 @@ void Depot::Disuse()
  * Of all the depot parts a depot has, return the best destination for a vehicle.
  * @param v The vehicle.
  * @param dep The depot vehicle \a v is heading for.
- * @return The closest part of depot to vehicle v.
+ * @return The free and closest (if none is free, just closest) part of depot to vehicle v.
  */
 TileIndex Depot::GetBestDepotTile(Vehicle *v) const
 {
 	assert(this->veh_type == v->type);
 	TileIndex best_depot = INVALID_TILE;
+	DepotReservation best_found_type = DEPOT_RESERVATION_END;
 	uint best_distance = UINT_MAX;
 
 	for (const auto &tile : this->depot_tiles) {
+		bool check_south = v->type == VEH_ROAD;
 		uint new_distance = DistanceManhattan(v->tile, tile);
-		if (new_distance < best_distance) {
+again:
+		DepotReservation depot_reservation = GetDepotReservation(tile, check_south);
+		if (((best_found_type == depot_reservation) && new_distance < best_distance) || (depot_reservation < best_found_type)) {
 			best_depot = tile;
 			best_distance = new_distance;
+			best_found_type = depot_reservation;
+		}
+		if (check_south) {
+			/* For road vehicles, check north direction as well. */
+			check_south = false;
+			goto again;
 		}
 	}
 

src/depot_map.h

@@ -83,4 +83,96 @@ inline VehicleType GetDepotVehicleType(Tile t)
 	}
 }
 
+/** Return true if a tile belongs to an extended depot. */
+static inline bool IsExtendedDepot(Tile tile) {
+	assert(IsValidTile(tile));
+	assert(IsDepotTile(tile));
+	if (IsAirportTile(tile)) return false;
+	return HasBit(tile.m5(), 5);
+}
+
+/** Return true if a tile belongs to an extended depot. */
+static inline bool IsExtendedDepotTile(TileIndex tile) {
+	if (!IsValidTile(tile)) return false;
+	if (!IsDepotTile(tile)) return false;
+	return IsExtendedDepot(tile);
+}
+
+/**
+ * Has this depot some vehicle servicing or stopped inside?
+ * @param tile tile of the depot.
+ * @param south_dir In case of road transport, return reservation facing south if true.
+ * @return The type of reservation on this tile (empty, servicing or occupied).
+ * @pre is a depot tile
+ */
+static inline DepotReservation GetDepotReservation(Tile t, bool south_dir = false)
+{
+	assert(IsDepotTile(t));
+	if (!IsExtendedDepot(t)) return DEPOT_RESERVATION_EMPTY;
+	if (south_dir) {
+		assert(GetDepotVehicleType(t) == VEH_ROAD);
+		return (DepotReservation)GB(t.m6(), 4, 2);
+	}
+	return (DepotReservation)GB(t.m4(), 6, 2);
+}
+
+/**
+ * Is this a platform/depot tile full with stopped vehicles?
+ * @param tile tile of the depot.
+ * @param south_dir In case of road transport, check reservation facing south if true.
+ * @return the type of reservation of the depot.
+ * @pre is a depot tile
+ */
+static inline bool IsDepotFullWithStoppedVehicles(TileIndex t, bool south_dir = false)
+{
+	assert(IsDepotTile(t));
+	if (!IsExtendedDepot(t)) return false;
+	return GetDepotReservation(t, south_dir) == DEPOT_RESERVATION_FULL_STOPPED_VEH;
+}
+
+
+/**
+ * Has this depot tile/platform some vehicle inside?
+ * @param tile tile of the depot.
+ * @param south_dir In case of road transport, check reservation facing south if true.
+ * @return true iff depot tile/platform has no vehicle.
+ * @pre IsExtendedDepotTile
+ */
+static inline bool IsExtendedDepotEmpty(TileIndex t, bool south_dir = false)
+{
+	assert(IsExtendedDepotTile(t));
+	return GetDepotReservation(t, south_dir) == DEPOT_RESERVATION_EMPTY;
+}
+
+/**
+ * Mark whether this depot has a ship inside.
+ * @param tile of the depot.
+ * @param reservation type of reservation
+ * @param south_dir Whether to set south direction reservation.
+ * @pre tile is an extended ship depot.
+ */
+static inline void SetDepotReservation(Tile t, DepotReservation reservation, bool south_dir = false)
+{
+	assert(IsDepotTile(t));
+	if (!IsExtendedDepot(t)) return;
+	switch (GetTileType(t)) {
+		default: NOT_REACHED();
+		case MP_RAILWAY:
+			break;
+		case MP_ROAD:
+			if (south_dir) {
+				SB(t.m6(), 4, 2, reservation);
+				return;
+			}
+			break;
+		case MP_WATER:
+			assert(GetDepotReservation(t) == GetDepotReservation(GetOtherShipDepotTile(t)));
+			SB(Tile(GetOtherShipDepotTile(t)).m4(), 6, 2, reservation);
+			break;
+		case MP_STATION: return;
+	}
+
+	SB(t.m4(), 6, 2, reservation);
+}
+
 #endif /* DEPOT_MAP_H */

src/depot_type.h

@@ -18,4 +18,12 @@ static const DepotID NEW_DEPOT     = INVALID_DEPOT - 1;
 
 static const uint MAX_LENGTH_DEPOT_NAME_CHARS = 32; ///< The maximum length of a depot name in characters including '\0'
 
+/** Type of reservation of extended ship depots. */
+enum DepotReservation {
+	DEPOT_RESERVATION_EMPTY = 0,             ///< No vehicle servicing/stopped on depot tile/platform.
+	DEPOT_RESERVATION_IN_USE = 1,            ///< At least a vehicle is in the depot, but the depot tile is not full of stopped vehicles.
+	DEPOT_RESERVATION_FULL_STOPPED_VEH = 2,  ///< The depot tile/platform is full with stopped vehicles.
+	DEPOT_RESERVATION_END
+};
+
 #endif /* DEPOT_TYPE_H */

src/lang/english.txt

@@ -910,6 +910,7 @@ STR_NEWS_TRAIN_IS_STUCK                                         :{WHITE}{VEHICLE
 STR_NEWS_VEHICLE_IS_LOST                                        :{WHITE}{VEHICLE} is lost
 STR_NEWS_VEHICLE_UNPROFITABLE_YEAR                              :{WHITE}{VEHICLE}'s profit last year was {CURRENCY_LONG}
 STR_NEWS_VEHICLE_UNPROFITABLE_PERIOD                            :{WHITE}{VEHICLE}'s profit last period was {CURRENCY_LONG}
+STR_NEWS_VEHICLE_CAN_T_FIND_FREE_DEPOT                          :{WHITE}{VEHICLE} can't find a free depot
 STR_NEWS_AIRCRAFT_DEST_TOO_FAR                                  :{WHITE}{VEHICLE} can't get to the next destination because it is out of range
 
 STR_NEWS_ORDER_REFIT_FAILED                                     :{WHITE}{VEHICLE} stopped because an ordered refit failed

src/pathfinder/pathfinder_func.h

@@ -66,13 +66,22 @@ static inline TileIndex CalcClosestDepotTile(DepotID depot_id, TileIndex tile)
 	}
 
 	TileIndex best_tile = INVALID_TILE;
+	DepotReservation best_found_type = dep->veh_type == VEH_SHIP ? DEPOT_RESERVATION_END : DEPOT_RESERVATION_EMPTY;
 	uint best_distance = UINT_MAX;
 
 	for (auto const &depot_tile : dep->depot_tiles) {
 		uint new_distance = DistanceManhattan(depot_tile, tile);
-		if (new_distance < best_distance) {
+		bool check_south_direction = dep->veh_type == VEH_ROAD;
+again:
+		DepotReservation depot_reservation = GetDepotReservation(depot_tile, check_south_direction);
+		if (((best_found_type == depot_reservation) && new_distance < best_distance) || (depot_reservation < best_found_type)) {
 			best_tile = depot_tile;
 			best_distance = new_distance;
+			best_found_type = depot_reservation;
+		}
+		if (check_south_direction) {
+			check_south_direction = false;
+			goto again;
 		}
 	}
 

src/vehicle.cpp

@@ -790,6 +790,22 @@ void Vehicle::ShiftDates(TimerGameEconomy::Date interval)
  */
 void Vehicle::HandlePathfindingResult(bool path_found)
 {
+	if (this->dest_tile != INVALID_TILE && IsDepotTypeTile(this->dest_tile, (TransportType)this->type) && IsDepotFullWithStoppedVehicles(this->dest_tile)) {
+		/* Vehicle cannot find a free depot. */
+		/* Were we already lost? */
+		if (HasBit(this->vehicle_flags, VF_PATHFINDER_LOST)) return;
+
+		/* It is first time the problem occurred, set the "lost" flag. */
+		SetBit(this->vehicle_flags, VF_PATHFINDER_LOST);
+		/* Notify user about the event. */
+		AI::NewEvent(this->owner, new ScriptEventVehicleLost(this->index));
+		if (_settings_client.gui.lost_vehicle_warn && this->owner == _local_company) {
+			SetDParam(0, this->index);
+			AddVehicleAdviceNewsItem(STR_NEWS_VEHICLE_CAN_T_FIND_FREE_DEPOT, this->index);
+		}
+		return;
+	}
+
 	if (path_found) {
 		/* Route found, is the vehicle marked with "lost" flag? */
 		if (!HasBit(this->vehicle_flags, VF_PATHFINDER_LOST)) return;