Fix #10490: Allow ships to exit depots if another is not moving at the exit point...

[openttd-github.git] / src / script / api / script_road.hpp

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file script_road.hpp Everything to query and build roads. */

#ifndef SCRIPT_ROAD_HPP
#define SCRIPT_ROAD_HPP

#include "script_tile.hpp"
#include "../squirrel_helper_type.hpp"
#include "../../../road.h"

/**
 * Class that handles all road related functions.
 * @api ai game
 */
class ScriptRoad : public ScriptObject {
public:
        /**
         * All road related error messages.
         */
        enum ErrorMessages {
                /** Base for road building / maintaining errors */
                ERR_ROAD_BASE = ScriptError::ERR_CAT_ROAD << ScriptError::ERR_CAT_BIT_SIZE,

                /** Road works are in progress */
                ERR_ROAD_WORKS_IN_PROGRESS,                   // [STR_ERROR_ROAD_WORKS_IN_PROGRESS]

                /** Drive through is in the wrong direction */
                ERR_ROAD_DRIVE_THROUGH_WRONG_DIRECTION,       // [STR_ERROR_DRIVE_THROUGH_DIRECTION]

                /** Drive through roads can't be build on town owned roads */
                ERR_ROAD_CANNOT_BUILD_ON_TOWN_ROAD,           // [STR_ERROR_DRIVE_THROUGH_ON_TOWN_ROAD]

                /** One way roads can't have junctions */
                ERR_ROAD_ONE_WAY_ROADS_CANNOT_HAVE_JUNCTIONS, // [STR_ERROR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION]

                /** This roadtype cannot have crossings */
                ERR_ROADTYPE_DISALLOWS_CROSSING,              // [STR_ERROR_CROSSING_DISALLOWED_ROAD]

                /** No suitable road could be found */
                ERR_UNSUITABLE_ROAD,                          // [STR_ERROR_NO_SUITABLE_ROAD, STR_ERROR_NO_SUITABLE_TRAMWAY]
        };

        /**
         * Types of road known to the game.
         */
        enum RoadType {
                /* Note: these values represent part of the in-game static values */
                ROADTYPE_ROAD    = ::ROADTYPE_ROAD,    ///< Build road objects.
                ROADTYPE_TRAM    = ::ROADTYPE_TRAM,    ///< Build tram objects.

                /* Custom added value, only valid for this API */
                ROADTYPE_INVALID = -1,                 ///< Invalid RoadType.
        };

        /**
         * Road/tram types
         */
        enum RoadTramTypes : uint8_t {
                ROADTRAMTYPES_ROAD = ::RTTB_ROAD, ///< Road road types.
                ROADTRAMTYPES_TRAM = ::RTTB_TRAM, ///< Tram road types.
        };

        /**
         * Type of road station.
         */
        enum RoadVehicleType {
                ROADVEHTYPE_BUS,   ///< Build objects useable for busses and passenger trams
                ROADVEHTYPE_TRUCK, ///< Build objects useable for trucks and cargo trams
        };

        /**
         * Types of road-related objects in the game.
         */
        enum BuildType {
                BT_ROAD,       ///< Build a piece of road
                BT_DEPOT,      ///< Build a road depot
                BT_BUS_STOP,   ///< Build a bus stop
                BT_TRUCK_STOP, ///< Build a truck stop
        };

        /**
         * Get the name of a road type.
         * @param road_type The road type to get the name of.
         * @pre IsRoadTypeAvailable(road_type).
         * @return The name the road type has.
         */
        static std::optional<std::string> GetName(RoadType road_type);

        /**
         * Determines whether a busstop or a truckstop is needed to transport a certain cargo.
         * @param cargo_type The cargo to test.
         * @pre ScriptCargo::IsValidCargo(cargo_type).
         * @return The road vehicle type needed to transport the cargo.
         */
        static RoadVehicleType GetRoadVehicleTypeForCargo(CargoID cargo_type);

        /**
         * Checks whether the given tile is actually a tile with road that can be
         *  used to traverse a tile. This excludes road depots and 'normal' road
         *  stations, but includes drive through stations.
         * @param tile The tile to check.
         * @pre ScriptMap::IsValidTile(tile).
         * @return True if and only if the tile has road.
         */
        static bool IsRoadTile(TileIndex tile);

        /**
         * Checks whether the given tile is actually a tile with a road depot.
         * @param tile The tile to check.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @return True if and only if the tile has a road depot.
         */
        static bool IsRoadDepotTile(TileIndex tile);

        /**
         * Checks whether the given tile is actually a tile with a road station.
         * @param tile The tile to check.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @return True if and only if the tile has a road station.
         */
        static bool IsRoadStationTile(TileIndex tile);

        /**
         * Checks whether the given tile is actually a tile with a drive through
         *  road station.
         * @param tile The tile to check.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @return True if and only if the tile has a drive through road station.
         */
        static bool IsDriveThroughRoadStationTile(TileIndex tile);

        /**
         * Check if a given RoadType is available.
         * @param road_type The RoadType to check for.
         * @game @pre ScriptCompanyMode::IsValid().
         * @return True if this RoadType can be used.
         */
        static bool IsRoadTypeAvailable(RoadType road_type);

        /**
         * Get the current RoadType set for all ScriptRoad functions.
         * @return The RoadType currently set.
         */
        static RoadType GetCurrentRoadType();

        /**
         * Set the RoadType for all further ScriptRoad functions.
         * @param road_type The RoadType to set.
         */
        static void SetCurrentRoadType(RoadType road_type);

        /**
         * Check if a road vehicle built for a road type can run on another road type.
         * @param engine_road_type The road type the road vehicle is built for.
         * @param road_road_type The road type you want to check.
         * @pre ScriptRoad::IsRoadTypeAvailable(engine_road_type).
         * @pre ScriptRoad::IsRoadTypeAvailable(road_road_type).
         * @return Whether a road vehicle built for 'engine_road_type' can run on 'road_road_type'.
         */
        static bool RoadVehCanRunOnRoad(ScriptRoad::RoadType engine_road_type, ScriptRoad::RoadType road_road_type);

        /**
         * Check if a road vehicle built for a road type has power on another road type.
         * @param engine_road_type The road type the road vehicle is built for.
         * @param road_road_type The road type you want to check.
         * @pre ScriptRoad::IsRoadTypeAvailable(engine_road_type).
         * @pre ScriptRoad::IsRoadTypeAvailable(road_road_type).
         * @return Whether a road vehicle built for 'engine_road_type' has power on 'road_road_type'.
         */
        static bool RoadVehHasPowerOnRoad(ScriptRoad::RoadType engine_road_type, ScriptRoad::RoadType road_road_type);


        /**
         * Convert the road on all tiles within a rectangle to another RoadType.
         * @param start_tile One corner of the rectangle.
         * @param end_tile The opposite corner of the rectangle.
         * @param road_type The RoadType you want to convert.
         * @pre ScriptMap::IsValidTile(start_tile).
         * @pre ScriptMap::IsValidTile(end_tile).
         * @pre IsRoadTypeAvailable(road_type).
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptRoad::ERR_UNSUITABLE_ROAD
         * @return Whether at least some road has been converted successfully.
         */
        static bool ConvertRoadType(TileIndex start_tile, TileIndex end_tile, RoadType road_type);

        /**
         * Check if a given tile has RoadType.
         * @param tile The tile to check.
         * @param road_type The RoadType to check for.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre IsRoadTypeAvailable(road_type).
         * @return True if the tile contains a RoadType object.
         */
        static bool HasRoadType(TileIndex tile, RoadType road_type);

        /**
         * Checks whether the given tiles are directly connected, i.e. whether
         *  a road vehicle can travel from the center of the first tile to the
         * center of the second tile.
         * @param tile_from The source tile.
         * @param tile_to The destination tile.
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @pre ScriptMap::IsValidTile(tile_from).
         * @pre ScriptMap::IsValidTile(tile_to).
         * @pre 'tile_from' and 'tile_to' are directly neighbouring tiles.
         * @return True if and only if a road vehicle can go from tile_from to tile_to.
         */
        static bool AreRoadTilesConnected(TileIndex tile_from, TileIndex tile_to);

        /**
         * Lookup function for building road parts independent of whether the
         *  "building on slopes" setting is enabled or not.
         *  This implementation can be used for abstract reasoning about a tile as
         *  it needs the slope and existing road parts of the tile as information.
         * @param slope The slope of the tile to examine.
         * @param existing An array with the existing neighbours in the same format
         *                 as "start" and "end", e.g. ScriptMap.GetTileIndex(0, 1).
         *                 As a result of this all values of the existing array
         *                 must be of type integer.
         * @param start The tile from where the 'tile to be considered' will be
         *              entered. This is a relative tile, so valid parameters are:
         *              ScriptMap.GetTileIndex(0, 1), ScriptMap.GetTileIndex(0, -1),
         *              ScriptMap.GetTileIndex(1, 0) and ScriptMap.GetTileIndex(-1, 0).
         * @param end The tile from where the 'tile to be considered' will be
         *            exited. This is a relative tile, sovalid parameters are:
         *              ScriptMap.GetTileIndex(0, 1), ScriptMap.GetTileIndex(0, -1),
         *              ScriptMap.GetTileIndex(1, 0) and ScriptMap.GetTileIndex(-1, 0).
         * @pre start != end.
         * @pre slope must be a valid slope, i.e. one specified in ScriptTile::Slope.
         * @note Passing data that would be invalid in-game, e.g. existing containing
         *       road parts that can not be build on a tile with the given slope,
         *       does not necessarily means that -1 is returned, i.e. not all
         *       preconditions written here or assumed by the game are extensively
         *       checked to make sure the data entered is valid.
         * @return 0 when the build parts do not connect, 1 when they do connect once
         *         they are build or 2 when building the first part automatically
         *         builds the second part. -1 means the preconditions are not met.
         */
        static SQInteger CanBuildConnectedRoadParts(ScriptTile::Slope slope, Array<> &&existing, TileIndex start, TileIndex end);

        /**
         * Lookup function for building road parts independent of whether the
         *  "building on slopes" setting is enabled or not.
         *  This implementation can be used for reasoning about an existing tile.
         * @param tile The tile to examine.
         * @param start The tile from where "tile" will be entered.
         * @param end The tile from where "tile" will be exited.
         * @pre start != end.
         * @pre tile != start.
         * @pre tile != end.
         * @pre ScriptMap.IsValidTile(tile).
         * @pre ScriptMap.IsValidTile(start).
         * @pre ScriptMap.IsValidTile(end).
         * @pre ScriptMap.GetDistanceManhattanToTile(tile, start) == 1.
         * @pre ScriptMap.GetDistanceManhattanToTile(tile, end) == 1.
         * @return 0 when the build parts do not connect, 1 when they do connect once
         *         they are build or 2 when building the first part automatically
         *         builds the second part. -1 means the preconditions are not met.
         */
        static SQInteger CanBuildConnectedRoadPartsHere(TileIndex tile, TileIndex start, TileIndex end);

        /**
         * Count how many neighbours are road.
         * @param tile The tile to check on.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @return 0 means no neighbour road; max value is 4.
         */
        static SQInteger GetNeighbourRoadCount(TileIndex tile);

        /**
         * Gets the tile in front of a road depot.
         * @param depot The road depot tile.
         * @pre IsRoadDepotTile(depot).
         * @return The tile in front of the depot.
         */
        static TileIndex GetRoadDepotFrontTile(TileIndex depot);

        /**
         * Gets the tile in front of a road station.
         * @param station The road station tile.
         * @pre IsRoadStationTile(station).
         * @return The tile in front of the road station.
         */
        static TileIndex GetRoadStationFrontTile(TileIndex station);

        /**
         * Gets the tile at the back of a drive through road station.
         *  So, one side of the drive through station is retrieved with
         *  GetTileInFrontOfStation, the other with this function.
         * @param station The road station tile.
         * @pre IsDriveThroughRoadStationTile(station).
         * @return The tile at the back of the drive through road station.
         */
        static TileIndex GetDriveThroughBackTile(TileIndex station);

        /**
         * Builds a road from the center of tile start to the center of tile end.
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @exception ScriptError::ERR_ALREADY_BUILT
         * @exception ScriptError::ERR_LAND_SLOPED_WRONG
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptRoad::ERR_ROAD_ONE_WAY_ROADS_CANNOT_HAVE_JUNCTIONS
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @note Construction will fail if an obstacle is found between the start and end tiles.
         * @game @note Building a piece of road as deity (ScriptCompanyMode::IsDeity()) results in a piece of road owned by towns.
         * @return Whether the road has been/can be build or not.
         */
        static bool BuildRoad(TileIndex start, TileIndex end);

        /**
         * Builds a one-way road from the center of tile start to the center
         *  of tile end. If the road already exists, it is made one-way road.
         *  If the road already exists and is already one-way in this direction,
         *  the road is made two-way again. If the road already exists but is
         *  one-way in the other direction, it's made a 'no'-way road (it's
         *  forbidden to enter the tile from any direction).
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre GetCurrentRoadType() == ROADTYPE_ROAD.
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_ALREADY_BUILT
         * @exception ScriptError::ERR_LAND_SLOPED_WRONG
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptRoad::ERR_ROAD_ONE_WAY_ROADS_CANNOT_HAVE_JUNCTIONS
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @note Construction will fail if an obstacle is found between the start and end tiles.
         * @return Whether the road has been/can be build or not.
         */
        static bool BuildOneWayRoad(TileIndex start, TileIndex end);

        /**
         * Builds a road from the edge of tile start to the edge of tile end (both
         *  included).
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @exception ScriptError::ERR_ALREADY_BUILT
         * @exception ScriptError::ERR_LAND_SLOPED_WRONG
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptRoad::ERR_ROAD_ONE_WAY_ROADS_CANNOT_HAVE_JUNCTIONS
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @note Construction will fail if an obstacle is found between the start and end tiles.
         * @game @note Building a piece of road as deity (ScriptCompanyMode::IsDeity()) results in a piece of road owned by towns.
         * @return Whether the road has been/can be build or not.
         */
        static bool BuildRoadFull(TileIndex start, TileIndex end);

        /**
         * Builds a one-way road from the edge of tile start to the edge of tile end
         *  (both included). If the road already exists, it is made one-way road.
         *  If the road already exists and is already one-way in this direction,
         *  the road is made two-way again. If the road already exists but is
         *  one-way in the other direction, it's made a 'no'-way road (it's
         *  forbidden to enter the tile from any direction).
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre GetCurrentRoadType() == ROADTYPE_ROAD.
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_ALREADY_BUILT
         * @exception ScriptError::ERR_LAND_SLOPED_WRONG
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptRoad::ERR_ROAD_ONE_WAY_ROADS_CANNOT_HAVE_JUNCTIONS
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @note Construction will fail if an obstacle is found between the start and end tiles.
         * @return Whether the road has been/can be build or not.
         */
        static bool BuildOneWayRoadFull(TileIndex start, TileIndex end);

        /**
         * Builds a road depot.
         * @param tile Place to build the depot.
         * @param front The tile exactly in front of the depot.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre ScriptMap::IsValidTile(front).
         * @pre 'tile' is not equal to 'front', but in a straight line of it.
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_FLAT_LAND_REQUIRED
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @return Whether the road depot has been/can be build or not.
         */
        static bool BuildRoadDepot(TileIndex tile, TileIndex front);

        /**
         * Builds a road bus or truck station.
         * @param tile Place to build the station.
         * @param front The tile exactly in front of the station.
         * @param road_veh_type Whether to build a truck or bus station.
         * @param station_id The station to join, ScriptStation::STATION_NEW or ScriptStation::STATION_JOIN_ADJACENT.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre ScriptMap::IsValidTile(front).
         * @pre 'tile' is not equal to 'front', but in a straight line of it.
         * @pre station_id == ScriptStation::STATION_NEW || station_id == ScriptStation::STATION_JOIN_ADJACENT || ScriptStation::IsValidStation(station_id).
         * @pre GetCurrentRoadType() == ROADTYPE_ROAD.
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptError::ERR_FLAT_LAND_REQUIRED
         * @exception ScriptRoad::ERR_ROAD_DRIVE_THROUGH_WRONG_DIRECTION
         * @exception ScriptRoad::ERR_ROAD_CANNOT_BUILD_ON_TOWN_ROAD
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @exception ScriptStation::ERR_STATION_TOO_CLOSE_TO_ANOTHER_STATION
         * @exception ScriptStation::ERR_STATION_TOO_MANY_STATIONS
         * @exception ScriptStation::ERR_STATION_TOO_MANY_STATIONS_IN_TOWN
         * @return Whether the station has been/can be build or not.
         */
        static bool BuildRoadStation(TileIndex tile, TileIndex front, RoadVehicleType road_veh_type, StationID station_id);

        /**
         * Builds a drive-through road bus or truck station.
         * @param tile Place to build the station.
         * @param front A tile on the same axis with 'tile' as the station shall be oriented.
         * @param road_veh_type Whether to build a truck or bus station.
         * @param station_id The station to join, ScriptStation::STATION_NEW or ScriptStation::STATION_JOIN_ADJACENT.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre ScriptMap::IsValidTile(front).
         * @pre 'tile' is not equal to 'front', but in a straight line of it.
         * @pre station_id == ScriptStation::STATION_NEW || station_id == ScriptStation::STATION_JOIN_ADJACENT || ScriptStation::IsValidStation(station_id).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_AREA_NOT_CLEAR
         * @exception ScriptError::ERR_FLAT_LAND_REQUIRED
         * @exception ScriptRoad::ERR_ROAD_DRIVE_THROUGH_WRONG_DIRECTION
         * @exception ScriptRoad::ERR_ROAD_CANNOT_BUILD_ON_TOWN_ROAD
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @exception ScriptStation::ERR_STATION_TOO_CLOSE_TO_ANOTHER_STATION
         * @exception ScriptStation::ERR_STATION_TOO_MANY_STATIONS
         * @exception ScriptStation::ERR_STATION_TOO_MANY_STATIONS_IN_TOWN
         * @return Whether the station has been/can be build or not.
         */
        static bool BuildDriveThroughRoadStation(TileIndex tile, TileIndex front, RoadVehicleType road_veh_type, StationID station_id);

        /**
         * Removes a road from the center of tile start to the center of tile end.
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @return Whether the road has been/can be removed or not.
         */
        static bool RemoveRoad(TileIndex start, TileIndex end);

        /**
         * Removes a road from the edge of tile start to the edge of tile end (both
         *  included).
         * @param start The start tile of the road.
         * @param end The end tile of the road.
         * @pre 'start' is not equal to 'end'.
         * @pre ScriptMap::IsValidTile(start).
         * @pre ScriptMap::IsValidTile(end).
         * @pre 'start' and 'end' are in a straight line, i.e.
         *  ScriptMap::GetTileX(start) == ScriptMap::GetTileX(end) or
         *  ScriptMap::GetTileY(start) == ScriptMap::GetTileY(end).
         * @pre IsRoadTypeAvailable(GetCurrentRoadType()).
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @exception ScriptRoad::ERR_ROAD_WORKS_IN_PROGRESS
         * @return Whether the road has been/can be removed or not.
         */
        static bool RemoveRoadFull(TileIndex start, TileIndex end);

        /**
         * Removes a road depot.
         * @param tile Place to remove the depot from.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre Tile is a road depot.
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @return Whether the road depot has been/can be removed or not.
         */
        static bool RemoveRoadDepot(TileIndex tile);

        /**
         * Removes a road bus or truck station.
         * @param tile Place to remove the station from.
         * @pre ScriptMap::IsValidTile(tile).
         * @pre Tile is a road station.
         * @game @pre ScriptCompanyMode::IsValid().
         * @exception ScriptError::ERR_OWNED_BY_ANOTHER_COMPANY
         * @exception ScriptError::ERR_VEHICLE_IN_THE_WAY
         * @return Whether the station has been/can be removed or not.
         */
        static bool RemoveRoadStation(TileIndex tile);

        /**
         * Get the baseprice of building a road-related object.
         * @param roadtype the roadtype of the object to build
         * @param build_type the type of object to build
         * @pre IsRoadTypeAvailable(roadtype)
         * @return The baseprice of building the given object.
         */
        static Money GetBuildCost(RoadType roadtype, BuildType build_type);

        /**
         * Test if a road type is for road or trams.
         * @param roadtype the roadtype to test.
         * @return RoadTramTypes of the road types.
         */
        static RoadTramTypes GetRoadTramType(RoadType roadtype);

        /**
         * Get the maximum speed of road vehicles running on this roadtype.
         * @param road_type The roadtype to get the maximum speed of.
         * @pre IsRoadTypeAvailable(road_type)
         * @return The maximum speed road vehicles can run on this roadtype
         *   or 0 if there is no limit.
         * @note The speed is in OpenTTD's internal speed unit.
         *       This is mph / 0.8, which is roughly 0.5 km/h.
         *       To get km/h multiply this number by 2.01168.
         */
        static SQInteger GetMaxSpeed(RoadType road_type);

        /**
         * Get the maintenance cost factor of a road type.
         * @param roadtype The road type to get the maintenance factor of.
         * @pre IsRoadTypeAvailable(roadtype)
         * @return Maintenance cost factor of the roadtype.
         */
        static SQInteger GetMaintenanceCostFactor(RoadType roadtype);

private:

        /**
         * Internal function used by Build(OneWay)Road(Full).
         */
        static bool _BuildRoadInternal(TileIndex start, TileIndex end, bool one_way, bool full);

        /**
         * Internal function used by Build(DriveThrough)RoadStation.
         */
        static bool _BuildRoadStationInternal(TileIndex tile, TileIndex front, RoadVehicleType road_veh_type, bool drive_through, StationID station_id);
};

#endif /* SCRIPT_ROAD_HPP */