Initialize with OpenTTD 1.9.3

src/linkgraph/refresh.h

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+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file refresh.h Declaration of link refreshing utility. */
+
+#ifndef REFRESH_H
+#define REFRESH_H
+
+#include "../cargo_type.h"
+#include "../vehicle_base.h"
+#include <vector>
+#include <map>
+#include <set>
+
+/**
+ * Utility to refresh links a consist will visit.
+ */
+class LinkRefresher {
+public:
+	static void Run(Vehicle *v, bool allow_merge = true, bool is_full_loading = false);
+
+protected:
+	/**
+	 * Various flags about properties of the last examined link that might have
+	 * an influence on the next one.
+	 */
+	enum RefreshFlags {
+		USE_NEXT,     ///< There was a conditional jump. Try to use the given next order when looking for a new one.
+		HAS_CARGO,    ///< Consist could leave the last stop where it could interact with cargo carrying cargo (i.e. not an "unload all" + "no loading" order).
+		WAS_REFIT,    ///< Consist was refit since the last stop where it could interact with cargo.
+		RESET_REFIT,  ///< Consist had a chance to load since the last refit and the refit capacities can be reset.
+		IN_AUTOREFIT, ///< Currently doing an autorefit loop. Ignore the first autorefit order.
+	};
+
+	/**
+	 * Simulated cargo type and capacity for prediction of future links.
+	 */
+	struct RefitDesc {
+		CargoID cargo;    ///< Cargo type the vehicle will be carrying.
+		uint16 capacity;  ///< Capacity the vehicle will have.
+		uint16 remaining; ///< Capacity remaining from before the previous refit.
+		RefitDesc(CargoID cargo, uint16 capacity, uint16 remaining) :
+				cargo(cargo), capacity(capacity), remaining(remaining) {}
+	};
+
+	/**
+	 * A hop the refresh algorithm might evaluate. If the same hop is seen again
+	 * the evaluation is stopped. This of course is a fairly simple heuristic.
+	 * Sequences of refit orders can produce vehicles with all kinds of
+	 * different cargoes and remembering only one can lead to early termination
+	 * of the algorithm. However, as the order language is Turing complete, we
+	 * are facing the halting problem here. At some point we have to draw the
+	 * line.
+	 */
+	struct Hop {
+		OrderID from;  ///< Last order where vehicle could interact with cargo or absolute first order.
+		OrderID to;    ///< Next order to be processed.
+		CargoID cargo; ///< Cargo the consist is probably carrying or CT_INVALID if unknown.
+
+		/**
+		 * Default constructor should not be called but has to be visible for
+		 * usage in std::set.
+		 */
+		Hop() {NOT_REACHED();}
+
+		/**
+		 * Real constructor, only use this one.
+		 * @param from First order of the hop.
+		 * @param to Second order of the hop.
+		 * @param cargo Cargo the consist is probably carrying when passing the hop.
+		 */
+		Hop(OrderID from, OrderID to, CargoID cargo) : from(from), to(to), cargo(cargo) {}
+		bool operator<(const Hop &other) const;
+	};
+
+	typedef std::vector<RefitDesc> RefitList;
+	typedef std::set<Hop> HopSet;
+
+	Vehicle *vehicle;           ///< Vehicle for which the links should be refreshed.
+	uint capacities[NUM_CARGO]; ///< Current added capacities per cargo ID in the consist.
+	RefitList refit_capacities; ///< Current state of capacity remaining from previous refits versus overall capacity per vehicle in the consist.
+	HopSet *seen_hops;          ///< Hops already seen. If the same hop is seen twice we stop the algorithm. This is shared between all Refreshers of the same run.
+	CargoID cargo;              ///< Cargo given in last refit order.
+	bool allow_merge;           ///< If the refresher is allowed to merge or extend link graphs.
+	bool is_full_loading;       ///< If the vehicle is full loading.
+
+	LinkRefresher(Vehicle *v, HopSet *seen_hops, bool allow_merge, bool is_full_loading);
+
+	bool HandleRefit(CargoID refit_cargo);
+	void ResetRefit();
+	void RefreshStats(const Order *cur, const Order *next);
+	const Order *PredictNextOrder(const Order *cur, const Order *next, uint8 flags, uint num_hops = 0);
+
+	void RefreshLinks(const Order *cur, const Order *next, uint8 flags, uint num_hops = 0);
+};
+
+#endif /* REFRESH_H */