Function LoadUnloadVehicle

src/economy.cpp:1615–1922

* Loads/unload the vehicle if possible. * @param front the vehicle to be (un)loaded */

 * @param front the vehicle to be (un)loaded
 */
static void LoadUnloadVehicle(Vehicle *front)
{
	assert(front->current_order.IsType(OT_LOADING));

	StationID last_visited = front->last_station_visited;
	Station *st = Station::Get(last_visited);

	std::vector<StationID> next_station;
	front->GetNextStoppingStation(next_station);
	bool use_autorefit = front->current_order.IsRefit() && front->current_order.GetRefitCargo() == CARGO_AUTO_REFIT;
	CargoArray consist_capleft{};
	if (_settings_game.order.improved_load && use_autorefit ?
			front->cargo_payment == nullptr : (front->current_order.IsFullLoadOrder())) {
		ReserveConsist(st, front,
				(use_autorefit && front->load_unload_ticks != 0) ? &consist_capleft : nullptr,
				next_station);
	}

	/* We have not waited enough time till the next round of loading/unloading */
	if (front->load_unload_ticks != 0) return;

	if (front->type == VEH_TRAIN && (!IsTileType(front->tile, MP_STATION) || GetStationIndex(front->tile) != st->index)) {
		/* The train reversed in the station. Take the "easy" way
		 * out and let the train just leave as it always did. */
		front->vehicle_flags.Set(VehicleFlag::LoadingFinished);
		front->load_unload_ticks = 1;
		return;
	}

	int new_load_unload_ticks = 0;
	bool dirty_vehicle = false;
	bool dirty_station = false;

	bool completely_emptied = true;
	bool anything_unloaded  = false;
	bool anything_loaded    = false;
	CargoTypes full_load_amount = 0;
	CargoTypes cargo_not_full   = 0;
	CargoTypes cargo_full       = 0;
	CargoTypes reservation_left = 0;

	front->cur_speed = 0;

	CargoPayment *payment = front->cargo_payment;

	uint artic_part = 0; // Articulated part we are currently trying to load. (not counting parts without capacity)
	for (Vehicle *v = front; v != nullptr; v = v->Next()) {
		if (v == front || !v->Previous()->HasArticulatedPart()) artic_part = 0;
		if (v->cargo_cap == 0) continue;
		artic_part++;

		GoodsEntry *ge = &st->goods[v->cargo_type];

		if (v->vehicle_flags.Test(VehicleFlag::CargoUnloading) && front->current_order.GetUnloadType() != OrderUnloadType::NoUnload) {
			uint cargo_count = v->cargo.UnloadCount();
			uint amount_unloaded = _settings_game.order.gradual_loading ? std::min(cargo_count, GetLoadAmount(v)) : cargo_count;
			bool remaining = false; // Are there cargo entities in this vehicle that can still be unloaded here?