Function CreateRandomTown

src/town_cmd.cpp:2386–2425

* Create a random town somewhere in the world. * @param attempts How many times should we try? * @param townnameparts The name of the town. * @param size The size preset of the town. * @param city Should we build a city? * @param layout The road layout to build. * @return The town object, or nullptr if we failed to create a town anywhere. */

 * @return The town object, or nullptr if we failed to create a town anywhere.
 */
static Town *CreateRandomTown(uint attempts, uint32_t townnameparts, TownSize size, bool city, TownLayout layout)
{
	assert(_game_mode == GM_EDITOR || _generating_world); // These are the preconditions for CMD_DELETE_TOWN

	if (!Town::CanAllocateItem()) return nullptr;

	do {
		/* Generate a tile index not too close from the edge */
		TileIndex tile = AlignTileToGrid(RandomTile(), layout);

		/* If we tried to place the town on water, find a suitable land tile nearby.
		 * Otherwise, evaluate the land tile. */
		if (IsTileType(tile, MP_WATER)) {
			tile = FindNearestGoodCoastalTownSpot(tile, layout);
			if (tile == INVALID_TILE) continue;
		} else if (TownCanBePlacedHere(tile, true).Failed()) continue;

		/* Allocate a town struct */
		Town *t = new Town(tile);

		DoCreateTown(t, tile, townnameparts, size, city, layout, false);

		/* if the population is still 0 at the point, then the
		 * placement is so bad it couldn't grow at all */
		if (t->cache.population > 0) return t;

		Backup<CompanyID> cur_company(_current_company, OWNER_TOWN);
		[[maybe_unused]] CommandCost rc = Command<CMD_DELETE_TOWN>::Do(DoCommandFlag::Execute, t->index);
		cur_company.Restore();
		assert(rc.Succeeded());

		/* We already know that we can allocate a single town when
		 * entering this function. However, we create and delete
		 * a town which "resets" the allocation checks. As such we
		 * need to check again when assertions are enabled. */
		assert(Town::CanAllocateItem());
	} while (--attempts != 0);

	return nullptr;
}

/**
 * Calculate the number of towns which should be on the map according to the current "town density" newgame setting and the map size.