(svn r13940) -Add [YAPP]: YAPF is now able to reserve the found path. (michi_cc)

src/pbs.cpp

@@ -12,6 +12,9 @@
 #include "debug.h"
 #include "direction_func.h"
 #include "settings_type.h"
+#include "road_func.h"
+#include "vehicle_base.h"
+#include "yapf/follow_track.hpp"
 
 /**
  * Get the reserved trackbits for any tile, regardless of type.
@@ -155,3 +158,119 @@ bool TryReserveRailTrack(TileIndex tile, Track t)
 			break;
 	}
 }
+
+/**
+ * Follow a train reservation to the last tile.
+ *
+ * @param v the vehicle
+ * @returns The last tile of the reservation or the current train tile if no reservation present.
+ */
+PBSTileInfo FollowTrainReservation(const Vehicle *v)
+{
+	assert(v->type == VEH_TRAIN);
+
+	TileIndex tile = v->tile;
+	Trackdir  trackdir = GetVehicleTrackdir(v);
+
+	if (IsRailDepotTile(tile) && !GetRailDepotReservation(tile)) return PBSTileInfo(tile, trackdir, false);
+
+	/* Do not disallow 90 deg turns as the setting might have changed between reserving and now. */
+	CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
+	while (ft.Follow(tile, trackdir)) {
+		TrackdirBits reserved = (TrackdirBits)(ft.m_new_td_bits & (GetReservedTrackbits(ft.m_new_tile) * 0x101));
+
+		/* No reservation --> path end found */
+		if (reserved == TRACKDIR_BIT_NONE) break;
+
+		/* Can't have more than one reserved trackdir */
+		Trackdir new_trackdir = FindFirstTrackdir(reserved);
+
+		/* One-way signal against us. The reservation can't be ours as it is not
+		 * a safe position from our direction and we can never pass the signal. */
+		if (HasOnewaySignalBlockingTrackdir(ft.m_new_tile, new_trackdir)) break;
+
+		tile = ft.m_new_tile;
+		trackdir = new_trackdir;
+
+		/* Depot tile? Can't continue. */
+		if (IsRailDepotTile(tile)) break;
+		/* Non-pbs signal? Reservation can't continue. */
+		if (IsTileType(tile, MP_RAILWAY) && HasSignalOnTrackdir(tile, trackdir) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) break;
+	}
+
+	return PBSTileInfo(tile, trackdir, IsSafeWaitingPosition(v, tile, trackdir, true, _settings_game.pf.forbid_90_deg));
+}
+
+/**
+ * Determine whether a certain track on a tile is a safe position to end a path.
+ *
+ * @param v the vehicle to test for
+ * @param tile The tile
+ * @param trackdir The trackdir to test
+ * @param include_line_end Should end-of-line tiles be considered safe?
+ * @param forbid_90def Don't allow trains to make 90 degree turns
+ * @return True if it is a safe position
+ */
+bool IsSafeWaitingPosition(const Vehicle *v, TileIndex tile, Trackdir trackdir, bool include_line_end, bool forbid_90deg)
+{
+	if (IsRailDepotTile(tile)) return true;
+
+	if (IsTileType(tile, MP_RAILWAY)) {
+		/* For non-pbs signals, stop on the signal tile. */
+		if (HasSignalOnTrackdir(tile, trackdir) && !IsPbsSignal(GetSignalType(tile, TrackdirToTrack(trackdir)))) return true;
+	}
+
+	/* Check next tile. For perfomance reasons, we check for 90 degree turns ourself. */
+	CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
+
+	/* End of track? */
+	if (!ft.Follow(tile, trackdir)) {
+		/* Last tile of a terminus station is a safe position. */
+		if (include_line_end) return true;
+	}
+
+	/* Check for reachable tracks. */
+	ft.m_new_td_bits &= DiagdirReachesTrackdirs(ft.m_exitdir);
+	if (ft.m_new_td_bits == TRACKDIR_BIT_NONE) return include_line_end;
+	if (forbid_90deg) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
+
+	if (ft.m_new_td_bits != TRACKDIR_BIT_NONE && KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE) {
+		/* PBS signal on next trackdir? Safe position. */
+		if (HasPbsSignalOnTrackdir(ft.m_new_tile, FindFirstTrackdir(ft.m_new_td_bits))) return true;
+	}
+
+	return false;
+}
+
+/**
+ * Check if a safe position is free.
+ *
+ * @param v the vehicle to test for
+ * @param tile The tile
+ * @param trackdir The trackdir to test
+ * @param forbid_90def Don't allow trains to make 90 degree turns
+ * @return True if the position is free
+ */
+bool IsWaitingPositionFree(const Vehicle *v, TileIndex tile, Trackdir trackdir, bool forbid_90deg)
+{
+	Track     track = TrackdirToTrack(trackdir);
+	TrackBits reserved = GetReservedTrackbits(tile);
+
+	/* Tile reserved? Can never be a free waiting position. */
+	if (TrackOverlapsTracks(reserved, track)) return false;
+
+	/* Not reserved and depot or not a pbs signal -> free. */
+	if (IsRailDepotTile(tile)) return true;
+	if (IsTileType(tile, MP_RAILWAY) && HasSignalOnTrackdir(tile, trackdir) && !IsPbsSignal(GetSignalType(tile, track))) return true;
+
+	/* Check the next tile, if it's a PBS signal, it has to be free as well. */
+	CFollowTrackRail ft(v, GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes);
+
+	if (!ft.Follow(tile, trackdir)) return true;
+
+	/* Check for reachable tracks. */
+	ft.m_new_td_bits &= DiagdirReachesTrackdirs(ft.m_exitdir);
+	if (forbid_90deg) ft.m_new_td_bits &= ~TrackdirCrossesTrackdirs(trackdir);
+
+	return !HasReservedTracks(ft.m_new_tile, TrackdirBitsToTrackBits(ft.m_new_td_bits));
+}

src/pbs.h

@@ -8,6 +8,7 @@
 #include "tile_type.h"
 #include "direction_type.h"
 #include "track_type.h"
+#include "vehicle_type.h"
 
 TrackBits GetReservedTrackbits(TileIndex t);
 
@@ -16,6 +17,20 @@ void SetRailwayStationPlatformReservation(TileIndex start, DiagDirection dir, bo
 bool TryReserveRailTrack(TileIndex tile, Track t);
 void UnreserveRailTrack(TileIndex tile, Track t);
 
+/** This struct contains information about the end of a reserved path. */
+struct PBSTileInfo {
+	TileIndex tile;      ///< Tile the path ends, INVALID_TILE if no valid path was found.
+	Trackdir  trackdir;  ///< The reserved trackdir on the tile.
+	bool      okay;      ///< True if tile is a safe wairing position, false otherwise.
+
+	PBSTileInfo() : tile(INVALID_TILE), trackdir(INVALID_TRACKDIR), okay(false) {}
+	PBSTileInfo(TileIndex _t, Trackdir _td, bool _okay) : tile(_t), trackdir(_td), okay(_okay) {}
+};
+
+PBSTileInfo FollowTrainReservation(const Vehicle *v);
+bool IsSafeWaitingPosition(const Vehicle *v, TileIndex tile, Trackdir trackdir, bool include_line_end, bool forbid_90deg = false);
+bool IsWaitingPositionFree(const Vehicle *v, TileIndex tile, Trackdir trackdir, bool forbid_90deg = false);
+
 /**
  * Check whether some of tracks is reserved on a tile.
  *

src/rail_map.h

@@ -534,6 +534,21 @@ static inline bool HasPbsSignalOnTrackdir(TileIndex tile, Trackdir td)
 		IsPbsSignal(GetSignalType(tile, TrackdirToTrack(td)));
 }
 
+/**
+ * Is a one-way signal blocking the trackdir? A one-way signal on the
+ * trackdir against will block, but signals on both trackdirs won't.
+ * @param tile the tile to check
+ * @param td the trackdir to check
+ */
+static inline bool HasOnewaySignalBlockingTrackdir(TileIndex tile, Trackdir td)
+{
+	return
+		IsTileType(tile, MP_RAILWAY) &&
+		HasSignalOnTrackdir(tile, ReverseTrackdir(td)) &&
+		!HasSignalOnTrackdir(tile, td) &&
+		IsOnewaySignal(tile, TrackdirToTrack(td));
+}
+
 
 /**
  * Return the rail type of tile, or INVALID_RAILTYPE if this is no rail tile.

src/yapf/yapf.h

@@ -8,6 +8,7 @@
 #include "../debug.h"
 #include "../depot_type.h"
 #include "../direction_type.h"
+#include "../pbs.h"
 
 /** Finds the best path for given ship.
  * @param v        the ship that needs to find a path
@@ -32,9 +33,11 @@ Trackdir YapfChooseRoadTrack(const Vehicle *v, TileIndex tile, DiagDirection ent
  * @param enterdir diagonal direction which the RV will enter this new tile from
  * @param tracks   available trackdirs on the new tile (to choose from)
  * @param path_not_found [out] true is returned if no path can be found (returned Trackdir is only a 'guess')
+ * @param reserve_track indicates whether YAPF should try to reserve the found path
+ * @param target   [out] the target tile of the reservation, free is set to true if path was reserved
  * @return         the best trackdir for next turn or INVALID_TRACKDIR if the path could not be found
  */
-Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found);
+Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target);
 
 /** Used by RV multistop feature to find the nearest road stop that has a free slot.
  * @param v      RV (its current tile will be the origin)

src/yapf/yapf_node_rail.hpp

@@ -177,6 +177,37 @@ struct CYapfRailNodeT
 	FORCEINLINE Trackdir GetLastTrackdir() const {assert(m_segment != NULL); return m_segment->m_last_td;}
 	FORCEINLINE void SetLastTileTrackdir(TileIndex tile, Trackdir td) {assert(m_segment != NULL); m_segment->m_last_tile = tile; m_segment->m_last_td = td;}
 
+	template <class Tbase, class Tfunc, class Tpf>
+	bool IterateTiles(const Vehicle *v, Tpf &yapf, Tbase &obj, bool (Tfunc::*func)(TileIndex, Trackdir)) const
+	{
+		typename Tbase::TrackFollower ft(v, yapf.GetCompatibleRailTypes());
+		TileIndex cur = base::GetTile();
+		Trackdir  cur_td = base::GetTrackdir();
+
+		while (cur != GetLastTile() || cur_td != GetLastTrackdir()) {
+			if (!((obj.*func)(cur, cur_td))) return false;
+
+			ft.Follow(cur, cur_td);
+			cur = ft.m_new_tile;
+			assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
+			cur_td = FindFirstTrackdir(ft.m_new_td_bits);
+
+			/* Did we skip tiles because of a station? */
+			if (ft.m_is_station && ft.m_tiles_skipped > 0) {
+				TileIndexDiff diff = TileOffsByDiagDir(TrackdirToExitdir(cur_td));
+				TileIndex     tile = TILE_ADD(cur, -diff * ft.m_tiles_skipped);
+
+				/* Call func for all tiles in between. */
+				for (int i = 0; i < ft.m_tiles_skipped; ++i) {
+					if (!(obj.*func)(tile, cur_td)) return false;
+					tile = TILE_ADD(tile, diff);
+				}
+			}
+		}
+
+		return (obj.*func)(cur, cur_td);
+	}
+
 	void Dump(DumpTarget &dmp) const
 	{
 		base::Dump(dmp);

src/yapf/yapf_rail.cpp

@@ -9,6 +9,7 @@
 #include "yapf_costrail.hpp"
 #include "yapf_destrail.hpp"
 #include "../vehicle_func.h"
+#include "../pbs.h"
 
 #define DEBUG_YAPF_CACHE 0
 
@@ -16,7 +17,115 @@ int _total_pf_time_us = 0;
 
 
 
+template <class Types>
+class CYapfReserveTrack
+{
+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
 
+protected:
+	/// to access inherited pathfinder
+	FORCEINLINE Tpf& Yapf() {return *static_cast<Tpf*>(this);}
+
+private:
+	TileIndex m_res_dest;         ///< The reservation target tile
+	Trackdir  m_res_dest_td;      ///< The reservation target trackdir
+	Node      *m_res_node;        ///< The reservation target node
+	TileIndex m_res_fail_tile;    ///< The tile where the reservation failed
+	Trackdir  m_res_fail_td;      ///< The trackdir where the reservation failed
+
+	bool FindSafePositionProc(TileIndex tile, Trackdir td)
+	{
+		if (IsSafeWaitingPosition(Yapf().GetVehicle(), tile, td, true, !TrackFollower::Allow90degTurns())) {
+			m_res_dest = tile;
+			m_res_dest_td = td;
+			return false;   // Stop iterating segment
+		}
+		return true;
+	}
+
+	bool ReserveSingleTrack(TileIndex tile, Trackdir td)
+	{
+		if (!TryReserveRailTrack(tile, TrackdirToTrack(td))) {
+			/* Tile couldn't be reserved, undo. */
+			m_res_fail_tile = tile;
+			m_res_fail_td = td;
+			return false;
+		}
+		/* YAPF can sometimes skip parts of a station, so make sure we
+		 * always reserve the whole platform. */
+		if (IsRailwayStationTile(tile)) SetRailwayStationPlatformReservation(tile, TrackdirToExitdir(ReverseTrackdir(td)), true);
+		return tile != m_res_dest;
+	}
+
+	bool UnreserveSingleTrack(TileIndex tile, Trackdir td)
+	{
+		if (tile != m_res_fail_tile || td != m_res_fail_td) UnreserveRailTrack(tile, TrackdirToTrack(td));
+		return tile != m_res_dest && (tile != m_res_fail_tile || td != m_res_fail_td);
+	}
+
+public:
+	/** Set the target to where the reservation should be extended. */
+	inline void SetReservationTarget(Node *node, TileIndex tile, Trackdir td)
+	{
+		m_res_node = node;
+		m_res_dest = tile;
+		m_res_dest_td = td;
+	}
+
+	/** Check the node for a possible reservation target. */
+	inline void FindSafePositionOnNode(Node *node)
+	{
+		assert(node->m_parent != NULL);
+
+		/* We will never pass more than two signals, no need to check for a safe tile. */
+		if (node->m_parent->m_num_signals_passed >= 2) return;
+
+		if (!node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::FindSafePositionProc)) {
+			m_res_node = node;
+		}
+	}
+
+	/** Try to reserve the path till the reservation target. */
+	bool TryReservePath(PBSTileInfo *target)
+	{
+		m_res_fail_tile = INVALID_TILE;
+
+		if (target != NULL) {
+			target->tile = m_res_dest;
+			target->trackdir = m_res_dest_td;
+			target->okay = false;
+		}
+
+		/* Don't bother if the target is reserved. */
+		if (!IsWaitingPositionFree(Yapf().GetVehicle(), m_res_dest, m_res_dest_td)) return false;
+
+		for (Node *node = m_res_node; node->m_parent != NULL; node = node->m_parent) {
+			node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::ReserveSingleTrack);
+			if (m_res_fail_tile != INVALID_TILE) {
+				/* Reservation failed, undo. */
+				Node *fail_node = m_res_node;
+				TileIndex stop_tile = m_res_fail_tile;
+				do {
+					/* If this is the node that failed, stop at the failed tile. */
+					m_res_fail_tile = fail_node == node ? stop_tile : INVALID_TILE;
+					fail_node->IterateTiles(Yapf().GetVehicle(), Yapf(), *this, &CYapfReserveTrack<Types>::UnreserveSingleTrack);
+				} while (fail_node != node && (fail_node = fail_node->m_parent) != NULL);
+
+				return false;
+			}
+		}
+
+		if (target != NULL) target->okay = true;
+
+		if (Yapf().CanUseGlobalCache(*m_res_node))
+			YapfNotifyTrackLayoutChange(INVALID_TILE, INVALID_TRACK);
+
+		return true;
+	}
+};
 
 template <class Types>
 class CYapfFollowAnyDepotRailT
@@ -95,7 +204,7 @@ public:
 };
 
 template <class Types>
-class CYapfFollowRailT
+class CYapfFollowRailT : protected CYapfReserveTrack<Types>
 {
 public:
 	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
@@ -121,16 +230,18 @@ public:
 	/// return debug report character to identify the transportation type
 	FORCEINLINE char TransportTypeChar() const {return 't';}
 
-	static Trackdir stChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
+	static Trackdir stChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
 	{
 		// create pathfinder instance
 		Tpf pf1;
-		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found);
+#if !DEBUG_YAPF_CACHE
+		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
 
-#if DEBUG_YAPF_CACHE
+#else
+		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, false, NULL);
 		Tpf pf2;
 		pf2.DisableCache(true);
-		Trackdir result2 = pf2.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found);
+		Trackdir result2 = pf2.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
 		if (result1 != result2) {
 			DEBUG(yapf, 0, "CACHE ERROR: ChooseRailTrack() = [%d, %d]", result1, result2);
 			DumpTarget dmp1, dmp2;
@@ -148,10 +259,13 @@ public:
 		return result1;
 	}
 
-	FORCEINLINE Trackdir ChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
+	FORCEINLINE Trackdir ChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
 	{
+		if (target != NULL) target->tile = INVALID_TILE;
+
 		// set origin and destination nodes
-		Yapf().SetOrigin(v->tile, GetVehicleTrackdir(v), INVALID_TILE, INVALID_TRACKDIR, 1, true);
+		PBSTileInfo origin = FollowTrainReservation(v);
+		Yapf().SetOrigin(origin.tile, origin.trackdir, INVALID_TILE, INVALID_TRACKDIR, 1, true);
 		Yapf().SetDestination(v);
 
 		// find the best path
@@ -166,17 +280,23 @@ public:
 		Trackdir next_trackdir = INVALID_TRACKDIR;
 		Node *pNode = Yapf().GetBestNode();
 		if (pNode != NULL) {
+			// reserve till end of path
+			this->SetReservationTarget(pNode, pNode->GetLastTile(), pNode->GetLastTrackdir());
+
 			// path was found or at least suggested
 			// walk through the path back to the origin
 			Node* pPrev = NULL;
 			while (pNode->m_parent != NULL) {
 				pPrev = pNode;
 				pNode = pNode->m_parent;
+
+				this->FindSafePositionOnNode(pPrev);
 			}
 			// return trackdir from the best origin node (one of start nodes)
 			Node& best_next_node = *pPrev;
-			assert(best_next_node.GetTile() == tile);
 			next_trackdir = best_next_node.GetTrackdir();
+
+			if (reserve_track && path_found) this->TryReservePath(target);
 		}
 		return next_trackdir;
 	}
@@ -247,10 +367,10 @@ struct CYapfAnyDepotRail1 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail1, CFollowT
 struct CYapfAnyDepotRail2 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail2, CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};
 
 
-Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
+Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found, bool reserve_track, PBSTileInfo *target)
 {
 	// default is YAPF type 2
-	typedef Trackdir (*PfnChooseRailTrack)(const Vehicle*, TileIndex, DiagDirection, TrackBits, bool*);
+	typedef Trackdir (*PfnChooseRailTrack)(const Vehicle*, TileIndex, DiagDirection, TrackBits, bool*, bool, PBSTileInfo*);
 	PfnChooseRailTrack pfnChooseRailTrack = &CYapfRail1::stChooseRailTrack;
 
 	// check if non-default YAPF type needed
@@ -258,7 +378,7 @@ Trackdir YapfChooseRailTrack(const Vehicle *v, TileIndex tile, DiagDirection ent
 		pfnChooseRailTrack = &CYapfRail2::stChooseRailTrack; // Trackdir, forbid 90-deg
 	}
 
-	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, tracks, path_not_found);
+	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, tracks, path_not_found, reserve_track, target);
 
 	return td_ret;
 }
@@ -330,11 +450,8 @@ bool YapfFindNearestRailDepotTwoWay(const Vehicle *v, int max_distance, int reve
 
 	const Vehicle *last_veh = GetLastVehicleInChain(v);
 
-	TileIndex tile = v->tile;
+	PBSTileInfo origin = FollowTrainReservation(v);
 	TileIndex last_tile = last_veh->tile;
-
-	// their trackdirs
-	Trackdir td = GetVehicleTrackdir(v);
 	Trackdir td_rev = ReverseTrackdir(GetVehicleTrackdir(last_veh));
 
 	typedef bool (*PfnFindNearestDepotTwoWay)(const Vehicle*, TileIndex, Trackdir, TileIndex, Trackdir, int, int, TileIndex*, bool*);
@@ -345,7 +462,7 @@ bool YapfFindNearestRailDepotTwoWay(const Vehicle *v, int max_distance, int reve
 		pfnFindNearestDepotTwoWay = &CYapfAnyDepotRail2::stFindNearestDepotTwoWay; // Trackdir, forbid 90-deg
 	}
 
-	bool ret = pfnFindNearestDepotTwoWay(v, tile, td, last_tile, td_rev, max_distance, reverse_penalty, depot_tile, reversed);
+	bool ret = pfnFindNearestDepotTwoWay(v, origin.tile, origin.trackdir, last_tile, td_rev, max_distance, reverse_penalty, depot_tile, reversed);
 	return ret;
 }