Method GetNextStoppingStation

src/order_cmd.cpp:363–410

* Recursively determine the next deterministic station to stop at. * @param v The vehicle we're looking at. * @param first Order to start searching at or INVALID_VEH_ORDER_ID to start at cur_implicit_order_index + 1. * @param hops Number of orders we have already looked at. * @return Next stopping station or StationID::Invalid(). * @pre The vehicle is currently loading and v->last_station_vis

 * @note This function may draw a random number. Don't use it from the GUI.
 */
void OrderList::GetNextStoppingStation(std::vector<StationID> &next_station, const Vehicle *v, VehicleOrderID first, uint hops) const
{
	VehicleOrderID next = first;
	if (first == INVALID_VEH_ORDER_ID) {
		next = v->cur_implicit_order_index;
		if (next >= this->GetNumOrders()) {
			next = this->GetFirstOrder();
			if (next == INVALID_VEH_ORDER_ID) return;
		} else {
			/* GetNext never returns INVALID_VEH_ORDER_ID if there is a valid station in the list.
			 * As the given "next" is already valid and a station in the list, we
			 * don't have to check for INVALID_VEH_ORDER_ID here. */
			next = this->GetNext(next);
			assert(next != INVALID_VEH_ORDER_ID);
		}
	}

	auto orders = v->Orders();
	do {
		next = this->GetNextDecisionNode(next, ++hops);

		/* Resolve possibly nested conditionals by estimation. */
		while (next != INVALID_VEH_ORDER_ID && orders[next].IsType(OT_CONDITIONAL)) {
			/* We return both options of conditional orders. */
			VehicleOrderID skip_to = this->GetNextDecisionNode(orders[next].GetConditionSkipToOrder(), hops);
			VehicleOrderID advance = this->GetNextDecisionNode(this->GetNext(next), hops);
			if (advance == INVALID_VEH_ORDER_ID || advance == first || skip_to == advance) {
				next = (skip_to == first) ? INVALID_VEH_ORDER_ID : skip_to;
			} else if (skip_to == INVALID_VEH_ORDER_ID || skip_to == first) {
				next = (advance == first) ? INVALID_VEH_ORDER_ID : advance;
			} else {
				this->GetNextStoppingStation(next_station, v, skip_to, hops);
				this->GetNextStoppingStation(next_station, v, advance, hops);
				return;
			}
			++hops;
		}

		/* Don't return a next stop if the vehicle has to unload everything. */
		if (next == INVALID_VEH_ORDER_ID || ((orders[next].IsType(OT_GOTO_STATION) || orders[next].IsType(OT_IMPLICIT)) &&
				orders[next].GetDestination() == v->last_station_visited &&
				(orders[next].GetUnloadType() == OrderUnloadType::Transfer || orders[next].GetUnloadType() == OrderUnloadType::Unload))) {
			return;
		}
	} while (orders[next].IsType(OT_GOTO_DEPOT) || orders[next].GetDestination() == v->last_station_visited);

	next_station.push_back(orders[next].GetDestination().ToStationID());
}

/**
 * Insert a new order into the order chain.