Function CmdBuildRailWaypoint

src/waypoint_cmd.cpp:208–327

* Convert existing rail to waypoint. Eg build a waypoint station over * piece of rail * @param flags type of operation * @param start_tile northern most tile where waypoint will be built * @param axis orientation (Axis) * @param width width of waypoint * @param height height of waypoint * @param spec_class custom station class * @param spec_index custom station id * @param station_to_join

 * @return the cost of this operation or an error
 */
CommandCost CmdBuildRailWaypoint(DoCommandFlags flags, TileIndex start_tile, Axis axis, uint8_t width, uint8_t height, StationClassID spec_class, uint16_t spec_index, StationID station_to_join, bool adjacent)
{
	if (!IsValidAxis(axis)) return CMD_ERROR;
	/* Check if the given station class is valid */
	if (static_cast<uint>(spec_class) >= StationClass::GetClassCount()) return CMD_ERROR;
	const StationClass *cls = StationClass::Get(spec_class);
	if (!IsWaypointClass(*cls)) return CMD_ERROR;
	if (spec_index >= cls->GetSpecCount()) return CMD_ERROR;

	/* The number of parts to build */
	uint8_t count = axis == AXIS_X ? height : width;

	if ((axis == AXIS_X ? width : height) != 1) return CMD_ERROR;
	if (count == 0 || count > _settings_game.station.station_spread) return CMD_ERROR;

	bool reuse = (station_to_join != NEW_STATION);
	if (!reuse) station_to_join = StationID::Invalid();
	bool distant_join = (station_to_join != StationID::Invalid());

	if (distant_join && (!_settings_game.station.distant_join_stations || !Waypoint::IsValidID(station_to_join))) return CMD_ERROR;

	TileArea new_location(start_tile, width, height);

	/* only AddCost for non-existing waypoints */
	CommandCost cost(EXPENSES_CONSTRUCTION);
	for (TileIndex cur_tile : new_location) {
		if (!IsRailWaypointTile(cur_tile)) cost.AddCost(_price[PR_BUILD_WAYPOINT_RAIL]);
	}

	/* Make sure the area below consists of clear tiles. (OR tiles belonging to a certain rail station) */
	StationID est = StationID::Invalid();

	const StationSpec *spec = StationClass::Get(spec_class)->GetSpec(spec_index);
	RailStationTileLayout stl{spec, count, 1};

	/* Check whether the tiles we're building on are valid rail or not. */
	TileIndexDiff offset = TileOffsByAxis(OtherAxis(axis));
	for (auto [i, it, tile] = std::make_tuple(0, stl.begin(), start_tile); i < count; ++i, ++it, tile += offset) {
		CommandCost ret = IsValidTileForWaypoint(tile, axis, &est);
		if (ret.Failed()) return ret;

		ret = IsRailStationBridgeAboveOk(tile, spec, StationType::RailWaypoint, *it + axis);
		if (ret.Failed()) return ret;
	}

	Waypoint *wp = nullptr;
	CommandCost ret = FindJoiningWaypoint(est, station_to_join, adjacent, new_location, &wp, false);
	if (ret.Failed()) return ret;

	/* Check if there is an already existing, deleted, waypoint close to us that we can reuse. */
	TileIndex center_tile = start_tile + (count / 2) * offset;
	if (wp == nullptr && reuse) wp = FindDeletedWaypointCloseTo(center_tile, STR_SV_STNAME_WAYPOINT, _current_company, false);

	if (wp != nullptr) {
		/* Reuse an existing waypoint. */
		if (wp->owner != _current_company) return CommandCost(STR_ERROR_TOO_CLOSE_TO_ANOTHER_WAYPOINT);

		/* Check if we want to expand an already existing waypoint. */