/**

 * Check and update town and house values.

 *

 * Checked are the HouseIDs. Updated are the

 * town population the number of houses per

 * town, the town radius and the max passengers

 * of the town.

 */

void UpdateHousesAndTowns()

{

	Town *town;

	InitializeBuildingCounts();

	/* Reset town population and num_houses */

	FOR_ALL_TOWNS(town) {

		town->population = 0;

		town->num_houses = 0;

	}

	for (TileIndex t = 0; t < MapSize(); t++) {

		HouseID house_id;

		if (!IsTileType(t, MP_HOUSE)) continue;

		house_id = GetHouseType(t);

		if (!GetHouseSpecs(house_id)->enabled && house_id >= NEW_HOUSE_OFFSET) {

			/* The specs for this type of house are not available any more, so

			 * replace it with the substitute original house type. */

			house_id = _house_mngr.GetSubstituteID(house_id);

			SetHouseType(t, house_id);

		}

		town = GetTownByTile(t);

		IncreaseBuildingCount(town, house_id);

		if (IsHouseCompleted(t)) town->population += GetHouseSpecs(house_id)->population;

		/* Increase the number of houses for every house, but only once. */

		if (GetHouseNorthPart(house_id) == 0) town->num_houses++;

	}

	/* Update the population and num_house dependant values */

	FOR_ALL_TOWNS(town) {

		UpdateTownRadius(town);

		UpdateTownMaxPass(town);

	}

}