Function CmdBuildAirport

src/station_cmd.cpp:2627–2747

* Place an Airport. * @param flags operation to perform * @param tile tile where airport will be built * @param airport_type airport type, @see airport.h * @param layout airport layout * @param station_to_join station ID to join (NEW_STATION if build new one) * @param allow_adjacent allow airports directly adjacent to other airports. * @return the cost of this operation or an error */

 * @return the cost of this operation or an error
 */
CommandCost CmdBuildAirport(DoCommandFlags flags, TileIndex tile, uint8_t airport_type, uint8_t layout, StationID station_to_join, bool allow_adjacent)
{
	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 || !Station::IsValidID(station_to_join))) return CMD_ERROR;

	if (airport_type >= NUM_AIRPORTS) return CMD_ERROR;

	CommandCost ret = CheckIfAuthorityAllowsNewStation(tile, flags);
	if (ret.Failed()) return ret;

	/* Check if a valid, buildable airport was chosen for construction */
	const AirportSpec *as = AirportSpec::Get(airport_type);
	if (!as->IsAvailable() || layout >= as->layouts.size()) return CMD_ERROR;
	if (!as->IsWithinMapBounds(layout, tile)) return CMD_ERROR;

	Direction rotation = as->layouts[layout].rotation;
	int w = as->size_x;
	int h = as->size_y;
	if (rotation == DIR_E || rotation == DIR_W) std::swap(w, h);
	TileArea airport_area = TileArea(tile, w, h);

	if (w > _settings_game.station.station_spread || h > _settings_game.station.station_spread) {
		return CommandCost(STR_ERROR_STATION_TOO_SPREAD_OUT);
	}

	AirportTileTableIterator tile_iter(as->layouts[layout].tiles, tile);
	CommandCost cost = CheckFlatLandAirport(tile_iter, flags);
	if (cost.Failed()) return cost;

	/* The noise level is the noise from the airport and reduce it to account for the distance to the town center. */
	uint dist;
	Town *nearest = AirportGetNearestTown(as, rotation, tile, std::move(tile_iter), dist);
	uint newnoise_level = GetAirportNoiseLevelForDistance(as, dist);

	/* Check if local auth would allow a new airport */
	StringID authority_refuse_message = STR_NULL;
	Town *authority_refuse_town = nullptr;

	if (_settings_game.economy.station_noise_level) {
		/* do not allow to build a new airport if this raise the town noise over the maximum allowed by town */
		if ((nearest->noise_reached + newnoise_level) > nearest->MaxTownNoise()) {
			authority_refuse_message = STR_ERROR_LOCAL_AUTHORITY_REFUSES_NOISE;
			authority_refuse_town = nearest;
		}
	} else if (_settings_game.difficulty.town_council_tolerance != TOWN_COUNCIL_PERMISSIVE) {
		Town *t = ClosestTownFromTile(tile, UINT_MAX);
		uint num = 0;
		for (const Station *st : Station::Iterate()) {
			if (st->town == t && st->facilities.Test(StationFacility::Airport) && st->airport.type != AT_OILRIG) num++;
		}
		if (num >= 2) {
			authority_refuse_message = STR_ERROR_LOCAL_AUTHORITY_REFUSES_AIRPORT;
			authority_refuse_town = t;
		}
	}