Function ChangePopulation

src/town_cmd.cpp:442–451

* Change the town's population as recorded in the town cache, town label, and town directory. * @param t The town which has changed. * @param mod The population change (can be positive or negative). */

 * @param mod The population change (can be positive or negative).
 */
static void ChangePopulation(Town *t, int mod)
{
	t->cache.population += mod;
	if (_generating_town) [[unlikely]] return;

	InvalidateWindowData(WC_TOWN_VIEW, t->index); // Cargo requirements may appear/vanish for small populations
	if (_settings_client.gui.population_in_label) t->UpdateVirtCoord();

	InvalidateWindowData(WC_TOWN_DIRECTORY, 0, TDIWD_POPULATION_CHANGE);
}

/**
 * Get the total population, the sum of all towns in the world.