+
−/* $Id$ */
+
−
+
−/*
+
− * 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 yapf_road.cpp The road pathfinding. */
+
−
+
−#include "../../stdafx.h"
+
−#include "yapf.hpp"
+
−#include "yapf_node_road.hpp"
+
−#include "../../roadstop_base.h"
+
−
+
−
+
−template <class Types>
+
−class CYapfCostRoadT
+
−{
+
−public:
+
−	typedef typename Types::Tpf Tpf; ///< pathfinder (derived from THIS class)
+
−	typedef typename Types::TrackFollower TrackFollower; ///< track follower helper
+
−	typedef typename Types::NodeList::Titem Node; ///< this will be our node type
+
−	typedef typename Node::Key Key;    ///< key to hash tables
+
−
+
−protected:
+
−	/** to access inherited path finder */
+
−	Tpf& Yapf()
+
−	{
+
−		return *static_cast<Tpf*>(this);
+
−	}
+
−
+
−	int SlopeCost(TileIndex tile, TileIndex next_tile, Trackdir trackdir)
+
−	{
+
−		/* height of the center of the current tile */
+
−		int x1 = TileX(tile) * TILE_SIZE;
+
−		int y1 = TileY(tile) * TILE_SIZE;
+
−		int z1 = GetSlopeZ(x1 + TILE_SIZE / 2, y1 + TILE_SIZE / 2);
+
−
+
−		/* height of the center of the next tile */
+
−		int x2 = TileX(next_tile) * TILE_SIZE;
+
−		int y2 = TileY(next_tile) * TILE_SIZE;
+
−		int z2 = GetSlopeZ(x2 + TILE_SIZE / 2, y2 + TILE_SIZE / 2);
+
−
+
−		if (z2 - z1 > 1) {
+
−			/* Slope up */
+
−			return Yapf().PfGetSettings().road_slope_penalty;
+
−		}
+
−		return 0;
+
−	}
+
−
+
−	/** return one tile cost */
+
−	FORCEINLINE int OneTileCost(TileIndex tile, Trackdir trackdir)
+
−	{
+
−		int cost = 0;
+
−		/* set base cost */
+
−		if (IsDiagonalTrackdir(trackdir)) {
+
−			cost += YAPF_TILE_LENGTH;
+
−			switch (GetTileType(tile)) {
+
−				case MP_ROAD:
+
−					/* Increase the cost for level crossings */
+
−					if (IsLevelCrossing(tile)) {
+
−						cost += Yapf().PfGetSettings().road_crossing_penalty;
+
−					}
+
−					break;
+
−
+
−				case MP_STATION: {
+
−					const RoadStop *rs = RoadStop::GetByTile(tile, GetRoadStopType(tile));
+
−					if (IsDriveThroughStopTile(tile)) {
+
−						/* Increase the cost for drive-through road stops */
+
−						cost += Yapf().PfGetSettings().road_stop_penalty;
+
−						DiagDirection dir = TrackdirToExitdir(trackdir);
+
−						if (!RoadStop::IsDriveThroughRoadStopContinuation(tile, tile - TileOffsByDiagDir(dir))) {
+
−							/* When we're the first road stop in a 'queue' of them we increase
+
−							 * cost based on the fill percentage of the whole queue. */
+
−							const RoadStop::Entry *entry = rs->GetEntry(dir);
+
−							cost += entry->GetOccupied() * Yapf().PfGetSettings().road_stop_occupied_penalty / entry->GetLength();
+
−						}
+
−					} else {
+
−						/* Increase cost for filled road stops */
+
−						cost += Yapf().PfGetSettings().road_stop_bay_occupied_penalty * (!rs->IsFreeBay(0) + !rs->IsFreeBay(1)) / 2;
+
−					}
+
−					break;
+
−				}
+
−
+
−				default:
+
−					break;
+
−			}
+
−		} else {
+
−			/* non-diagonal trackdir */
+
−			cost = YAPF_TILE_CORNER_LENGTH + Yapf().PfGetSettings().road_curve_penalty;
+
−		}
+
−		return cost;
+
−	}
+
−
+
−public:
+
−	/**
+
−	 * Called by YAPF to calculate the cost from the origin to the given node.
+
−	 *  Calculates only the cost of given node, adds it to the parent node cost
+
−	 *  and stores the result into Node::m_cost member
+
−	 */
+
−	FORCEINLINE bool PfCalcCost(Node& n, const TrackFollower *tf)
+
−	{
+
−		int segment_cost = 0;
+
−		uint tiles = 0;
+
−		/* start at n.m_key.m_tile / n.m_key.m_td and walk to the end of segment */
+
−		TileIndex tile = n.m_key.m_tile;
+
−		Trackdir trackdir = n.m_key.m_td;
+
−		for (;;) {
+
−			/* base tile cost depending on distance between edges */
+
−			segment_cost += Yapf().OneTileCost(tile, trackdir);
+
−
+
−			const RoadVehicle *v = Yapf().GetVehicle();
+
−			/* we have reached the vehicle's destination - segment should end here to avoid target skipping */
+
−			if (Yapf().PfDetectDestinationTile(tile, trackdir)) break;
+
−
+
−			/* stop if we have just entered the depot */
+
−			if (IsRoadDepotTile(tile) && trackdir == DiagDirToDiagTrackdir(ReverseDiagDir(GetRoadDepotDirection(tile)))) {
+
−				/* next time we will reverse and leave the depot */
+
−				break;
+
−			}
+
−
+
−			/* if there are no reachable trackdirs on new tile, we have end of road */
+
−			TrackFollower F(Yapf().GetVehicle());
+
−			if (!F.Follow(tile, trackdir)) break;
+
−
+
−			/* if there are more trackdirs available & reachable, we are at the end of segment */
+
−			if (KillFirstBit(F.m_new_td_bits) != TRACKDIR_BIT_NONE) break;
+
−
+
−			Trackdir new_td = (Trackdir)FindFirstBit2x64(F.m_new_td_bits);
+
−
+
−			/* stop if RV is on simple loop with no junctions */
+
−			if (F.m_new_tile == n.m_key.m_tile && new_td == n.m_key.m_td) return false;
+
−
+
−			/* if we skipped some tunnel tiles, add their cost */
+
−			segment_cost += F.m_tiles_skipped * YAPF_TILE_LENGTH;
+
−			tiles += F.m_tiles_skipped + 1;
+
−
+
−			/* add hilly terrain penalty */
+
−			segment_cost += Yapf().SlopeCost(tile, F.m_new_tile, trackdir);
+
−
+
−			/* add min/max speed penalties */
+
−			int min_speed = 0;
+
−			int max_veh_speed = v->GetDisplayMaxSpeed();
+
−			int max_speed = F.GetSpeedLimit(&min_speed);
+
−			if (max_speed < max_veh_speed) segment_cost += 1 * (max_veh_speed - max_speed);
+
−			if (min_speed > max_veh_speed) segment_cost += 10 * (min_speed - max_veh_speed);
+
−
+
−			/* move to the next tile */
+
−			tile = F.m_new_tile;
+
−			trackdir = new_td;
+
−			if (tiles > MAX_MAP_SIZE) break;
+
−		}
+
−
+
−		/* save end of segment back to the node */
+
−		n.m_segment_last_tile = tile;
+
−		n.m_segment_last_td = trackdir;
+
−
+
−		/* save also tile cost */
+
−		int parent_cost = (n.m_parent != NULL) ? n.m_parent->m_cost : 0;
+
−		n.m_cost = parent_cost + segment_cost;
+
−		return true;
+
−	}
+
−};
+
−
+
−
+
−template <class Types>
+
−class CYapfDestinationAnyDepotRoadT
+
−{
+
−public:
+
−	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+
−	typedef typename Types::TrackFollower TrackFollower;
+
−	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+
−	typedef typename Node::Key Key;                      ///< key to hash tables
+
−
+
−	/** to access inherited path finder */
+
−	Tpf& Yapf()
+
−	{
+
−		return *static_cast<Tpf*>(this);
+
−	}
+
−
+
−	/** Called by YAPF to detect if node ends in the desired destination */
+
−	FORCEINLINE bool PfDetectDestination(Node& n)
+
−	{
+
−		bool bDest = IsRoadDepotTile(n.m_segment_last_tile);
+
−		return bDest;
+
−	}
+
−
+
−	FORCEINLINE bool PfDetectDestinationTile(TileIndex tile, Trackdir trackdir)
+
−	{
+
−		return IsRoadDepotTile(tile);
+
−	}
+
−
+
−	/**
+
−	 * Called by YAPF to calculate cost estimate. Calculates distance to the destination
+
−	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate
+
−	 */
+
−	FORCEINLINE bool PfCalcEstimate(Node& n)
+
−	{
+
−		n.m_estimate = n.m_cost;
+
−		return true;
+
−	}
+
−};
+
−
+
−
+
−template <class Types>
+
−class CYapfDestinationTileRoadT
+
−{
+
−public:
+
−	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+
−	typedef typename Types::TrackFollower TrackFollower;
+
−	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+
−	typedef typename Node::Key Key;                      ///< key to hash tables
+
−
+
−protected:
+
−	TileIndex    m_destTile;
+
−	TrackdirBits m_destTrackdirs;
+
−	StationID    m_dest_station;
+
−	bool         m_bus;
+
−	bool         m_non_artic;
+
−
+
−public:
+
−	void SetDestination(const RoadVehicle *v)
+
−	{
+
−		if (v->current_order.IsType(OT_GOTO_STATION)) {
+
−			m_dest_station  = v->current_order.GetDestination();
+
−			m_bus           = v->IsBus();
+
−			m_destTile      = CalcClosestStationTile(m_dest_station, v->tile, m_bus ? STATION_BUS : STATION_TRUCK);
+
−			m_non_artic     = !v->HasArticulatedPart();
+
−			m_destTrackdirs = INVALID_TRACKDIR_BIT;
+
−		} else {
+
−			m_dest_station  = INVALID_STATION;
+
−			m_destTile      = v->dest_tile;
+
−			m_destTrackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(v->dest_tile, TRANSPORT_ROAD, v->compatible_roadtypes));
+
−		}
+
−	}
+
−
+
−protected:
+
−	/** to access inherited path finder */
+
−	Tpf& Yapf()
+
−	{
+
−		return *static_cast<Tpf*>(this);
+
−	}
+
−
+
−public:
+
−	/** Called by YAPF to detect if node ends in the desired destination */
+
−	FORCEINLINE bool PfDetectDestination(Node& n)
+
−	{
+
−		return PfDetectDestinationTile(n.m_segment_last_tile, n.m_segment_last_td);
+
−	}
+
−
+
−	FORCEINLINE bool PfDetectDestinationTile(TileIndex tile, Trackdir trackdir)
+
−	{
+
−		if (m_dest_station != INVALID_STATION) {
+
−			return IsTileType(tile, MP_STATION) &&
+
−				GetStationIndex(tile) == m_dest_station &&
+
−				(m_bus ? IsBusStop(tile) : IsTruckStop(tile)) &&
+
−				(m_non_artic || IsDriveThroughStopTile(tile));
+
−		}
+
−
+
−		return tile == m_destTile && ((m_destTrackdirs & TrackdirToTrackdirBits(trackdir)) != TRACKDIR_BIT_NONE);
+
−	}
+
−
+
−	/**
+
−	 * Called by YAPF to calculate cost estimate. Calculates distance to the destination
+
−	 *  adds it to the actual cost from origin and stores the sum to the Node::m_estimate
+
−	 */
+
−	inline bool PfCalcEstimate(Node& n)
+
−	{
+
−		static const int dg_dir_to_x_offs[] = {-1, 0, 1, 0};
+
−		static const int dg_dir_to_y_offs[] = {0, 1, 0, -1};
+
−		if (PfDetectDestination(n)) {
+
−			n.m_estimate = n.m_cost;
+
−			return true;
+
−		}
+
−
+
−		TileIndex tile = n.m_segment_last_tile;
+
−		DiagDirection exitdir = TrackdirToExitdir(n.m_segment_last_td);
+
−		int x1 = 2 * TileX(tile) + dg_dir_to_x_offs[(int)exitdir];
+
−		int y1 = 2 * TileY(tile) + dg_dir_to_y_offs[(int)exitdir];
+
−		int x2 = 2 * TileX(m_destTile);
+
−		int y2 = 2 * TileY(m_destTile);
+
−		int dx = abs(x1 - x2);
+
−		int dy = abs(y1 - y2);
+
−		int dmin = min(dx, dy);
+
−		int dxy = abs(dx - dy);
+
−		int d = dmin * YAPF_TILE_CORNER_LENGTH + (dxy - 1) * (YAPF_TILE_LENGTH / 2);
+
−		n.m_estimate = n.m_cost + d;
+
−		assert(n.m_estimate >= n.m_parent->m_estimate);
+
−		return true;
+
−	}
+
−};
+
−
+
−
+
−
+
−template <class Types>
+
−class CYapfFollowRoadT
+
−{
+
−public:
+
−	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
+
−	typedef typename Types::TrackFollower TrackFollower;
+
−	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
+
−	typedef typename Node::Key Key;                      ///< key to hash tables
+
−
+
−protected:
+
−	/** to access inherited path finder */
+
−	FORCEINLINE Tpf& Yapf()
+
−	{
+
−		return *static_cast<Tpf*>(this);
+
−	}
+
−
+
−public:
+
−
+
−	/**
+
−	 * Called by YAPF to move from the given node to the next tile. For each
+
−	 *  reachable trackdir on the new tile creates new node, initializes it
+
−	 *  and adds it to the open list by calling Yapf().AddNewNode(n)
+
−	 */
+
−	inline void PfFollowNode(Node& old_node)
+
−	{
+
−		TrackFollower F(Yapf().GetVehicle());
+
−		if (F.Follow(old_node.m_segment_last_tile, old_node.m_segment_last_td)) {
+
−			Yapf().AddMultipleNodes(&old_node, F);
+
−		}
+
−	}
+
−
+
−	/** return debug report character to identify the transportation type */
+
−	FORCEINLINE char TransportTypeChar() const
+
−	{
+
−		return 'r';
+
−	}
+
−
+
−	static Trackdir stChooseRoadTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, bool &path_found)
+
−	{
+
−		Tpf pf;
+
−		return pf.ChooseRoadTrack(v, tile, enterdir, path_found);
+
−	}
+
−
+
−	FORCEINLINE Trackdir ChooseRoadTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, bool &path_found)
+
−	{
+
−		/* Handle special case - when next tile is destination tile.
+
−		 * However, when going to a station the (initial) destination
+
−		 * tile might not be a station, but a junction, in which case
+
−		 * this method forces the vehicle to jump in circles. */
+
−		if (tile == v->dest_tile && !v->current_order.IsType(OT_GOTO_STATION)) {
+
−			/* choose diagonal trackdir reachable from enterdir */
+
−			return DiagDirToDiagTrackdir(enterdir);
+
−		}
+
−		/* our source tile will be the next vehicle tile (should be the given one) */
+
−		TileIndex src_tile = tile;
+
−		/* get available trackdirs on the start tile */
+
−		TrackdirBits src_trackdirs = TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, v->compatible_roadtypes));
+
−		/* select reachable trackdirs only */
+
−		src_trackdirs &= DiagdirReachesTrackdirs(enterdir);
+
−
+
−		/* set origin and destination nodes */
+
−		Yapf().SetOrigin(src_tile, src_trackdirs);
+
−		Yapf().SetDestination(v);
+
−
+
−		/* find the best path */
+
−		path_found = Yapf().FindPath(v);
+
−
+
−		/* if path not found - return INVALID_TRACKDIR */
+
−		Trackdir next_trackdir = INVALID_TRACKDIR;
+
−		Node *pNode = Yapf().GetBestNode();
+
−		if (pNode != NULL) {
+
−			/* path was found or at least suggested
+
−			 * walk through the path back to its origin */
+
−			while (pNode->m_parent != NULL) {
+
−				pNode = pNode->m_parent;
+
−			}
+
−			/* return trackdir from the best origin node (one of start nodes) */
+
−			Node& best_next_node = *pNode;
+
−			assert(best_next_node.GetTile() == tile);
+
−			next_trackdir = best_next_node.GetTrackdir();
+
−		}
+
−		return next_trackdir;
+
−	}
+
−
+
−	static uint stDistanceToTile(const RoadVehicle *v, TileIndex tile)
+
−	{
+
−		Tpf pf;
+
−		return pf.DistanceToTile(v, tile);
+
−	}
+
−
+
−	FORCEINLINE uint DistanceToTile(const RoadVehicle *v, TileIndex dst_tile)
+
−	{
+
−		/* handle special case - when current tile is the destination tile */
+
−		if (dst_tile == v->tile) {
+
−			/* distance is zero in this case */
+
−			return 0;
+
−		}
+
−
+
−		if (!SetOriginFromVehiclePos(v)) return UINT_MAX;
+
−
+
−		/* get available trackdirs on the destination tile */
+
−		Yapf().SetDestination(v);
+
−
+
−		/* if path not found - return distance = UINT_MAX */
+
−		uint dist = UINT_MAX;
+
−
+
−		/* find the best path */
+
−		if (!Yapf().FindPath(v)) return dist;
+
−
+
−		Node *pNode = Yapf().GetBestNode();
+
−		if (pNode != NULL) {
+
−			/* path was found
+
−			 * get the path cost estimate */
+
−			dist = pNode->GetCostEstimate();
+
−		}
+
−
+
−		return dist;
+
−	}
+
−
+
−	/** Return true if the valid origin (tile/trackdir) was set from the current vehicle position. */
+
−	FORCEINLINE bool SetOriginFromVehiclePos(const RoadVehicle *v)
+
−	{
+
−		/* set origin (tile, trackdir) */
+
−		TileIndex src_tile = v->tile;
+
−		Trackdir src_td = v->GetVehicleTrackdir();
+
−		if ((TrackStatusToTrackdirBits(GetTileTrackStatus(src_tile, TRANSPORT_ROAD, v->compatible_roadtypes)) & TrackdirToTrackdirBits(src_td)) == 0) {
+
−			/* sometimes the roadveh is not on the road (it resides on non-existing track)
+
−			 * how should we handle that situation? */
+
−			return false;
+
−		}
+
−		Yapf().SetOrigin(src_tile, TrackdirToTrackdirBits(src_td));
+
−		return true;
+
−	}
+
−
+
−	static bool stFindNearestDepot(const RoadVehicle *v, TileIndex tile, Trackdir td, int max_distance, TileIndex *depot_tile)
+
−	{
+
−		Tpf pf;
+
−		return pf.FindNearestDepot(v, tile, td, max_distance, depot_tile);
+
−	}
+
−
+
−	FORCEINLINE bool FindNearestDepot(const RoadVehicle *v, TileIndex tile, Trackdir td, int max_distance, TileIndex *depot_tile)
+
−	{
+
−		/* set origin and destination nodes */
+
−		Yapf().SetOrigin(tile, TrackdirToTrackdirBits(td));
+
−
+
−		/* find the best path */
+
−		bool bFound = Yapf().FindPath(v);
+
−		if (!bFound) return false;
+
−
+
−		/* some path found
+
−		 * get found depot tile */
+
−		Node *n = Yapf().GetBestNode();
+
−
+
−		if (max_distance > 0 && n->m_cost > max_distance * YAPF_TILE_LENGTH) return false;
+
−
+
−		*depot_tile = n->m_segment_last_tile;
+
−		return true;
+
−	}
+
−};
+
−
+
−template <class Tpf_, class Tnode_list, template <class Types> class Tdestination>
+
−struct CYapfRoad_TypesT
+
−{
+
−	typedef CYapfRoad_TypesT<Tpf_, Tnode_list, Tdestination>  Types;
+
−
+
−	typedef Tpf_                              Tpf;
+
−	typedef CFollowTrackRoad                  TrackFollower;
+
−	typedef Tnode_list                        NodeList;
+
−	typedef RoadVehicle                       VehicleType;
+
−	typedef CYapfBaseT<Types>                 PfBase;
+
−	typedef CYapfFollowRoadT<Types>           PfFollow;
+
−	typedef CYapfOriginTileT<Types>           PfOrigin;
+
−	typedef Tdestination<Types>               PfDestination;
+
−	typedef CYapfSegmentCostCacheNoneT<Types> PfCache;
+
−	typedef CYapfCostRoadT<Types>             PfCost;
+
−};
+
−
+
−struct CYapfRoad1         : CYapfT<CYapfRoad_TypesT<CYapfRoad1        , CRoadNodeListTrackDir, CYapfDestinationTileRoadT    > > {};
+
−struct CYapfRoad2         : CYapfT<CYapfRoad_TypesT<CYapfRoad2        , CRoadNodeListExitDir , CYapfDestinationTileRoadT    > > {};
+
−
+
−struct CYapfRoadAnyDepot1 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyDepot1, CRoadNodeListTrackDir, CYapfDestinationAnyDepotRoadT> > {};
+
−struct CYapfRoadAnyDepot2 : CYapfT<CYapfRoad_TypesT<CYapfRoadAnyDepot2, CRoadNodeListExitDir , CYapfDestinationAnyDepotRoadT> > {};
+
−
+
−
+
−Trackdir YapfRoadVehicleChooseTrack(const RoadVehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool &path_found)
+
−{
+
−	/* default is YAPF type 2 */
+
−	typedef Trackdir (*PfnChooseRoadTrack)(const RoadVehicle*, TileIndex, DiagDirection, bool &path_found);
+
−	PfnChooseRoadTrack pfnChooseRoadTrack = &CYapfRoad2::stChooseRoadTrack; // default: ExitDir, allow 90-deg
+
−
+
−	/* check if non-default YAPF type should be used */
+
−	if (_settings_game.pf.yapf.disable_node_optimization) {
+
−		pfnChooseRoadTrack = &CYapfRoad1::stChooseRoadTrack; // Trackdir, allow 90-deg
+
−	}
+
−
+
−	Trackdir td_ret = pfnChooseRoadTrack(v, tile, enterdir, path_found);
+
−	return (td_ret != INVALID_TRACKDIR) ? td_ret : (Trackdir)FindFirstBit2x64(trackdirs);
+
−}
+
−
+
−FindDepotData YapfRoadVehicleFindNearestDepot(const RoadVehicle *v, int max_distance)
+
−{
+
−	TileIndex tile = v->tile;
+
−	Trackdir trackdir = v->GetVehicleTrackdir();
+
−	if ((TrackStatusToTrackdirBits(GetTileTrackStatus(tile, TRANSPORT_ROAD, v->compatible_roadtypes)) & TrackdirToTrackdirBits(trackdir)) == 0) {
+
−		return FindDepotData();
+
−	}
+
−
+
−	/* default is YAPF type 2 */
+
−	typedef bool (*PfnFindNearestDepot)(const RoadVehicle*, TileIndex, Trackdir, int, TileIndex*);
+
−	PfnFindNearestDepot pfnFindNearestDepot = &CYapfRoadAnyDepot2::stFindNearestDepot;
+
−
+
−	/* check if non-default YAPF type should be used */
+
−	if (_settings_game.pf.yapf.disable_node_optimization) {
+
−		pfnFindNearestDepot = &CYapfRoadAnyDepot1::stFindNearestDepot; // Trackdir, allow 90-deg
+
−	}
+
−
+
−	FindDepotData fdd;
+
−	bool ret = pfnFindNearestDepot(v, tile, trackdir, max_distance, &fdd.tile);
+
−	fdd.best_length = ret ? max_distance / 2 : UINT_MAX; // some fake distance or NOT_FOUND
+
−	return fdd;
+
−}