Method PredictNextOrder

src/linkgraph/refresh.cpp:141–174

* Predict the next order the vehicle will execute and resolve conditionals by * recursion and return next non-conditional order in list. * @param cur Current order being evaluated. * @param next Next order to be evaluated. * @param flags RefreshFlags to give hints about the previous link and state carried over from that. * @param num_hops Number of hops already taken by recursive calls to thi

 * @return new next Order.
 */
VehicleOrderID LinkRefresher::PredictNextOrder(VehicleOrderID cur, VehicleOrderID next, RefreshFlags flags, uint num_hops)
{
	assert(this->vehicle->orders != nullptr);
	const OrderList &orderlist = *this->vehicle->orders;
	auto orders = orderlist.GetOrders();

	/* next is good if it's either nullptr (then the caller will stop the
	 * evaluation) or if it's not conditional and the caller allows it to be
	 * chosen (by setting RefreshFlag::UseNext). */
	while (next < orderlist.GetNumOrders() && (!flags.Test(RefreshFlag::UseNext) || orders[next].IsType(OT_CONDITIONAL))) {

		/* After the first step any further non-conditional order is good,
		 * regardless of previous RefreshFlag::UseNext settings. The case of cur and next or
		 * their respective stations being equal is handled elsewhere. */
		flags.Set(RefreshFlag::UseNext);

		if (orders[next].IsType(OT_CONDITIONAL)) {
			VehicleOrderID skip_to = orderlist.GetNextDecisionNode(orders[next].GetConditionSkipToOrder(), num_hops);
			if (skip_to != INVALID_VEH_ORDER_ID && num_hops < orderlist.GetNumOrders()) {
				/* Make copies of capacity tracking lists. There is potential
				 * for optimization here: If the vehicle never refits we don't
				 * need to copy anything. Also, if we've seen the branched link
				 * before we don't need to branch at all. */
				LinkRefresher branch(*this);
				branch.RefreshLinks(cur, skip_to, flags, num_hops + 1);
			}
		}

		/* Reassign next with the following stop. This can be a station or a
		 * depot.*/
		next = orderlist.GetNextDecisionNode(orderlist.GetNext(next), num_hops++);
	}
	return next;
}

/**
 * Refresh link stats for the given pair of orders.