Function TileLoop_Town

src/town_cmd.cpp:602–709

* Tile callback function. * * Tile callback function. Periodic tick handler for the tiles of a town. * @param tile been asked to do its stuff */

 * @param tile been asked to do its stuff
 */
static void TileLoop_Town(TileIndex tile)
{
	HouseID house_id = GetHouseType(tile);

	/* NewHouseTileLoop returns false if Callback 21 succeeded, i.e. the house
	 * doesn't exist any more, so don't continue here. */
	if (house_id >= NEW_HOUSE_OFFSET && !NewHouseTileLoop(tile)) return;

	if (!IsHouseCompleted(tile)) {
		/* Construction is not completed, so we advance a construction stage. */
		AdvanceHouseConstruction(tile);
		return;
	}

	const HouseSpec *hs = HouseSpec::Get(house_id);

	/* If the lift has a destination, it is already an animated tile. */
	if (hs->building_flags.Test(BuildingFlag::IsAnimated) &&
			house_id < NEW_HOUSE_OFFSET &&
			!LiftHasDestination(tile) &&
			Chance16(1, 2)) {
		AddAnimatedTile(tile);
	}

	Town *t = Town::GetByTile(tile);
	uint32_t r = Random();

	StationFinder stations(TileArea(tile, 1, 1));

	if (hs->callback_mask.Test(HouseCallbackMask::ProduceCargo)) {
		for (uint i = 0; i < 256; i++) {
			uint16_t callback = GetHouseCallback(CBID_HOUSE_PRODUCE_CARGO, i, r, house_id, t, tile);

			if (callback == CALLBACK_FAILED || callback == CALLBACK_HOUSEPRODCARGO_END) break;

			CargoType cargo = GetCargoTranslation(GB(callback, 8, 7), hs->grf_prop.grffile);
			if (!IsValidCargoType(cargo)) continue;

			uint amt = GB(callback, 0, 8);
			if (amt == 0) continue;

			/* NewGRF-supplied town cargos are not affected by recessions. */
			TownGenerateCargo(t, cargo, amt, stations, false);
		}
	} else {
		switch (_settings_game.economy.town_cargogen_mode) {
			case TCGM_ORIGINAL:
				/* Original (quadratic) cargo generation algorithm */
				TownGenerateCargoOriginal(t, TPE_PASSENGERS, hs->population, stations);
				TownGenerateCargoOriginal(t, TPE_MAIL, hs->mail_generation, stations);
				break;

			case TCGM_BITCOUNT:
				/* Binomial distribution per tick, by a series of coin flips */
				/* Reduce generation rate to a 1/4, using tile bits to spread out distribution.
				 * As tick counter is incremented by 256 between each call, we ignore the lower 8 bits. */
				if (GB(TimerGameTick::counter, 8, 2) == GB(tile.base(), 0, 2)) {
					TownGenerateCargoBinomial(t, TPE_PASSENGERS, hs->population, stations);