(svn r25891) -Feature: Use smallstack to allow for multiple next hops when loading and unloading.

7 files changed, 54 insertions, 67 deletions

diff --git a/src/cargopacket.cpp b/src/cargopacket.cpp
index 6a37cb488..9a1ba8568 100644
--- a/src/cargopacket.cpp
+++ b/src/cargopacket.cpp
@@ -421,7 +421,7 @@ void VehicleCargoList::SetTransferLoadPlace(TileIndex xy)
  * @param payment Payment object for registering transfers.
  * return If any cargo will be unloaded.
  */
-bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationID next_station, uint8 order_flags, const GoodsEntry *ge, CargoPayment *payment)
+bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationIDStack next_station, uint8 order_flags, const GoodsEntry *ge, CargoPayment *payment)
 {
 	this->AssertCountConsistency();
 	assert(this->action_counts[MTA_LOAD] == 0);
@@ -446,9 +446,24 @@ bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationID
 			action = MTA_DELIVER;
 		} else if (force_transfer) {
 			action = MTA_TRANSFER;
-			cargo_next = ge->GetVia(cp->source, current_station, next_station);
-			assert((cargo_next != next_station || cargo_next == INVALID_STATION) &&
-					cargo_next != current_station);
+			/* We cannot send the cargo to any of the possible next hops and
+			 * also not to the current station. */
+			FlowStatMap::const_iterator flow_it(ge->flows.find(cp->source));
+			if (flow_it == ge->flows.end()) {
+				cargo_next = INVALID_STATION;
+			} else {
+				FlowStat new_shares = flow_it->second;
+				new_shares.ChangeShare(current_station, INT_MIN);
+				StationIDStack excluded = next_station;
+				while (!excluded.IsEmpty()) {
+					new_shares.ChangeShare(excluded.Pop(), INT_MIN);
+				}
+				if (new_shares.GetShares()->empty()) {
+					cargo_next = INVALID_STATION;
+				} else {
+					cargo_next = new_shares.GetVia();
+				}
+			}
 		} else {
 			/* Rewrite an invalid source station to some random other one to
 			 * avoid keeping the cargo in the vehicle forever. */
@@ -460,7 +475,7 @@ bool VehicleCargoList::Stage(bool accepted, StationID current_station, StationID
 				action = (accepted && cp->source != current_station) ? MTA_DELIVER : MTA_KEEP;
 			} else if (cargo_next == current_station) {
 				action = MTA_DELIVER;
-			} else if (cargo_next == next_station) {
+			} else if (next_station.Contains(cargo_next)) {
 				action = MTA_KEEP;
 			} else {
 				action = MTA_TRANSFER;
@@ -667,10 +682,14 @@ bool StationCargoList::ShiftCargo(Taction &action, StationID next)
  * @return Amount of cargo actually moved.
  */
 template <class Taction>
-uint StationCargoList::ShiftCargo(Taction action, StationID next, bool include_invalid)
+uint StationCargoList::ShiftCargo(Taction action, StationIDStack next, bool include_invalid)
 {
 	uint max_move = action.MaxMove();
-	if (this->ShiftCargo(action, next) && include_invalid && action.MaxMove() > 0) {
+	while (!next.IsEmpty()) {
+		this->ShiftCargo(action, next.Pop());
+		if (action.MaxMove() == 0) break;
+	}
+	if (include_invalid && action.MaxMove() > 0) {
 		this->ShiftCargo(action, INVALID_STATION);
 	}
 	return max_move - action.MaxMove();
@@ -735,10 +754,10 @@ uint StationCargoList::Truncate(uint max_move, StationCargoAmountMap *cargo_per_
  * @param max_move Maximum amount of cargo to reserve.
  * @param dest VehicleCargoList to reserve for.
  * @param load_place Tile index of the current station.
- * @param next_station Next station the loading vehicle will visit.
+ * @param next_station Next station(s) the loading vehicle will visit.
  * @return Amount of cargo actually reserved.
  */
-uint StationCargoList::Reserve(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next_station)
+uint StationCargoList::Reserve(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationIDStack next_station)
 {
 	return this->ShiftCargo(CargoReservation(this, dest, max_move, load_place), next_station, true);
 }
@@ -749,13 +768,13 @@ uint StationCargoList::Reserve(uint max_move, VehicleCargoList *dest, TileIndex
  * @param max_move Amount of cargo to load.
  * @param dest Vehicle cargo list where the cargo resides.
  * @param load_place The new loaded_at_xy to be assigned to packets being moved.
- * @param next_station Next station the loading vehicle will visit.
+ * @param next_station Next station(s) the loading vehicle will visit.
  * @return Amount of cargo actually loaded.
  * @note Vehicles may or may not reserve, depending on their orders. The two
  *       modes of loading are exclusive, though. If cargo is reserved we don't
  *       need to load unreserved cargo.
  */
-uint StationCargoList::Load(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next_station)
+uint StationCargoList::Load(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationIDStack next_station)
 {
 	uint move = min(dest->ActionCount(VehicleCargoList::MTA_LOAD), max_move);
 	if (move > 0) {
diff --git a/src/cargopacket.h b/src/cargopacket.h
index c4ea9e144..3ae9e9927 100644
--- a/src/cargopacket.h
+++ b/src/cargopacket.h
@@ -409,7 +409,7 @@ public:
 
 	void SetTransferLoadPlace(TileIndex xy);
 
-	bool Stage(bool accepted, StationID current_station, StationID next_station, uint8 order_flags, const GoodsEntry *ge, CargoPayment *payment);
+	bool Stage(bool accepted, StationID current_station, StationIDStack next_station, uint8 order_flags, const GoodsEntry *ge, CargoPayment *payment);
 
 	/**
 	 * Marks all cargo in the vehicle as to be kept. This is mostly useful for
@@ -483,7 +483,7 @@ public:
 	bool ShiftCargo(Taction &action, StationID next);
 
 	template<class Taction>
-	uint ShiftCargo(Taction action, StationID next, bool include_invalid);
+	uint ShiftCargo(Taction action, StationIDStack next, bool include_invalid);
 
 	void Append(CargoPacket *cp, StationID next);
 
@@ -492,9 +492,13 @@ public:
 	 * @param next Station the cargo is headed for.
 	 * @return If there is any cargo for that station.
 	 */
-	inline bool HasCargoFor(StationID next) const
+	inline bool HasCargoFor(StationIDStack next) const
 	{
-		return this->packets.find(next) != this->packets.end();
+		while (!next.IsEmpty()) {
+			if (this->packets.find(next.Pop()) != this->packets.end()) return true;
+		}
+		/* Packets for INVALID_STTION can go anywhere. */
+		return this->packets.find(INVALID_STATION) != this->packets.end();
 	}
 
 	/**
@@ -539,8 +543,8 @@ public:
 	 * amount of cargo to be moved. Second parameter is destination (if
 	 * applicable), return value is amount of cargo actually moved. */
 
-	uint Reserve(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next);
-	uint Load(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationID next);
+	uint Reserve(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationIDStack next);
+	uint Load(uint max_move, VehicleCargoList *dest, TileIndex load_place, StationIDStack next);
 	uint Truncate(uint max_move = UINT_MAX, StationCargoAmountMap *cargo_per_source = NULL);
 	uint Reroute(uint max_move, StationCargoList *dest, StationID avoid, StationID avoid2, const GoodsEntry *ge);
 
diff --git a/src/economy.cpp b/src/economy.cpp
index e936b5678..270cedc67 100644
--- a/src/economy.cpp
+++ b/src/economy.cpp
@@ -1232,7 +1232,7 @@ void PrepareUnload(Vehicle *front_v)
 	assert(CargoPayment::CanAllocateItem());
 	front_v->cargo_payment = new CargoPayment(front_v);
 
-	StationID next_station = front_v->GetNextStoppingStation();
+	StationIDStack next_station = front_v->GetNextStoppingStation();
 	if (front_v->orders.list == NULL || (front_v->current_order.GetUnloadType() & OUFB_NO_UNLOAD) == 0) {
 		Station *st = Station::Get(front_v->last_station_visited);
 		for (Vehicle *v = front_v; v != NULL; v = v->Next()) {
@@ -1295,9 +1295,9 @@ static uint GetLoadAmount(Vehicle *v)
  * @param st Station where the consist is loading at the moment.
  * @param u Front of the loading vehicle consist.
  * @param consist_capleft If given, save free capacities after reserving there.
- * @param next_station Station the vehicle will stop at next.
+ * @param next_station Station(s) the vehicle will stop at next.
  */
-static void ReserveConsist(Station *st, Vehicle *u, CargoArray *consist_capleft, StationID next_station)
+static void ReserveConsist(Station *st, Vehicle *u, CargoArray *consist_capleft, StationIDStack next_station)
 {
 	Vehicle *next_cargo = u;
 	uint32 seen_cargos = 0;
@@ -1363,7 +1363,7 @@ static void LoadUnloadVehicle(Vehicle *front)
 	StationID last_visited = front->last_station_visited;
 	Station *st = Station::Get(last_visited);
 
-	StationID next_station = front->GetNextStoppingStation();
+	StationIDStack next_station = front->GetNextStoppingStation();
 	bool use_autorefit = front->current_order.IsRefit() && front->current_order.GetRefitCargo() == CT_AUTO_REFIT;
 	CargoArray consist_capleft;
 	if (_settings_game.order.improved_load &&
@@ -1497,8 +1497,7 @@ static void LoadUnloadVehicle(Vehicle *front)
 				CargoID cid;
 				new_cid = v_start->cargo_type;
 				FOR_EACH_SET_CARGO_ID(cid, refit_mask) {
-					if (st->goods[cid].cargo.HasCargoFor(next_station) ||
-							st->goods[cid].cargo.HasCargoFor(INVALID_STATION)) {
+					if (st->goods[cid].cargo.HasCargoFor(next_station)) {
 						/* Try to find out if auto-refitting would succeed. In case the refit is allowed,
 						 * the returned refit capacity will be greater than zero. */
 						DoCommand(v_start->tile, v_start->index, cid | 1U << 6 | 0xFF << 8 | 1U << 16, DC_QUERY_COST, GetCmdRefitVeh(v_start)); // Auto-refit and only this vehicle including artic parts.
diff --git a/src/order_base.h b/src/order_base.h
index 9965b9e5f..85d8a05a7 100644
--- a/src/order_base.h
+++ b/src/order_base.h
@@ -263,7 +263,7 @@ public:
 	 */
 	inline VehicleOrderID GetNumManualOrders() const { return this->num_manual_orders; }
 
-	StationID GetNextStoppingStation(const Vehicle *v, const Order *first = NULL) const;
+	StationIDStack GetNextStoppingStation(const Vehicle *v, const Order *first = NULL) const;
 	const Order *GetNextDecisionNode(const Order *next, uint hops) const;
 
 	void InsertOrderAt(Order *new_order, int index);
diff --git a/src/order_cmd.cpp b/src/order_cmd.cpp
index 52dd28496..c72f0d087 100644
--- a/src/order_cmd.cpp
+++ b/src/order_cmd.cpp
@@ -351,44 +351,6 @@ Order *OrderList::GetOrderAt(int index) const
 }
 
 /**
- * Choose between the two possible next orders so that the given consist can
- * load most cargo.
- * @param v Head of the consist.
- * @param o1 First order to choose from.
- * @param o2 Second order to choose from.
- * @return The best option of o1 and o2 and (recursively) possibly other conditionals.
- */
-StationID OrderList::GetBestLoadableNext(const Vehicle *v, const Order *o2, const Order *o1) const
-{
-	SmallMap<CargoID, uint> capacities;
-	v->GetConsistFreeCapacities(capacities);
-	uint loadable1 = 0;
-	uint loadable2 = 0;
-	StationID st1 = this->GetNextStoppingStation(v, o1);
-	StationID st2 = this->GetNextStoppingStation(v, o2);
-	const Station *cur_station = Station::Get(v->last_station_visited);
-	for (SmallPair<CargoID, uint> *i = capacities.Begin(); i != capacities.End(); ++i) {
-		const StationCargoPacketMap *loadable_packets = cur_station->goods[i->first].cargo.Packets();
-		uint loadable_cargo = 0;
-		std::pair<StationCargoPacketMap::const_iterator, StationCargoPacketMap::const_iterator> p =
-				loadable_packets->equal_range(st1);
-		for (StationCargoPacketMap::const_iterator j = p.first; j != p.second; ++j) {
-			loadable_cargo = (*j)->Count();
-		}
-		loadable1 += min(i->second, loadable_cargo);
-
-		loadable_cargo = 0;
-		p = loadable_packets->equal_range(st2);
-		for (StationCargoPacketMap::const_iterator j = p.first; j != p.second; ++j) {
-			loadable_cargo = (*j)->Count();
-		}
-		loadable2 += min(i->second, loadable_cargo);
-	}
-	if (loadable1 == loadable2) return RandomRange(2) == 0 ? st1 : st2;
-	return loadable1 > loadable2 ? st1 : st2;
-}
-
-/**
  * Get the next order which will make the given vehicle stop at a station
  * or refit at a depot or evaluate a non-trivial condition.
  * @param next The order to start looking at.
@@ -432,9 +394,8 @@ const Order *OrderList::GetNextDecisionNode(const Order *next, uint hops) const
  * @return Next stoppping station or INVALID_STATION.
  * @pre The vehicle is currently loading and v->last_station_visited is meaningful.
  * @note This function may draw a random number. Don't use it from the GUI.
- * @see OrderList::GetBestLoadableNext
  */
-StationID OrderList::GetNextStoppingStation(const Vehicle *v, const Order *first) const
+StationIDStack OrderList::GetNextStoppingStation(const Vehicle *v, const Order *first) const
 {
 
 	const Order *next = first;
@@ -472,7 +433,10 @@ StationID OrderList::GetNextStoppingStation(const Vehicle *v, const Order *first
 				} else if (skip_to == NULL) {
 					next = advance;
 				} else {
-					return this->GetBestLoadableNext(v, skip_to, advance);
+					StationIDStack st1 = this->GetNextStoppingStation(v, skip_to);
+					StationIDStack st2 = this->GetNextStoppingStation(v, advance);
+					while (!st2.IsEmpty()) st1.Push(st2.Pop());
+					return st1;
 				}
 			} else {
 				/* Otherwise we're optimistic and expect that the
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 19f7b3e64..b9797bdf3 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -4057,8 +4057,9 @@ uint FlowStat::GetShare(StationID st) const
 }
 
 /**
- * Get a station a package can be routed to, but exclude the given one.
+ * Get a station a package can be routed to, but exclude the given ones.
  * @param excluded StationID not to be selected.
+ * @param excluded2 Another StationID not to be selected.
  * @return A station ID from the shares map.
  */
 StationID FlowStat::GetVia(StationID excluded, StationID excluded2) const
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index ef5afa568..ddd74cec1 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -628,7 +628,7 @@ public:
 	 * Get the next station the vehicle will stop at.
 	 * @return ID of the next station the vehicle will stop at or INVALID_STATION.
 	 */
-	inline StationID GetNextStoppingStation() const
+	inline StationIDStack GetNextStoppingStation() const
 	{
 		return (this->orders.list == NULL) ? INVALID_STATION : this->orders.list->GetNextStoppingStation(this);
 	}