(svn r18420) -Codechange: split YAPF's track follower from the actual YAPF code

1 files changed, 455 insertions, 0 deletions

diff --git a/src/pathfinder/follow_track.hpp b/src/pathfinder/follow_track.hpp
new file mode 100644
index 000000000..62e36e1bc
--- /dev/null
+++ b/src/pathfinder/follow_track.hpp
@@ -0,0 +1,455 @@
+/* $Id$ */
+
+/*
+ * 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 follow_track.hpp Template function for track followers */
+
+#ifndef  FOLLOW_TRACK_HPP
+#define  FOLLOW_TRACK_HPP
+
+#include "../depot_map.h"
+#include "../pbs.h"
+#include "../roadveh.h"
+#include "../station_base.h"
+#include "../train.h"
+#include "../tunnelbridge.h"
+#include "../tunnelbridge_map.h"
+#include "pf_performance_timer.hpp"
+
+/** Track follower helper template class (can serve pathfinders and vehicle
+ *  controllers). See 6 different typedefs below for 3 different transport
+ *  types w/ or w/o 90-deg turns allowed */
+template <TransportType Ttr_type_, typename VehicleType, bool T90deg_turns_allowed_ = true, bool Tmask_reserved_tracks = false>
+struct CFollowTrackT
+{
+	enum ErrorCode {
+		EC_NONE,
+		EC_OWNER,
+		EC_RAIL_TYPE,
+		EC_90DEG,
+		EC_NO_WAY,
+		EC_RESERVED,
+	};
+
+	const VehicleType  *m_veh;           ///< moving vehicle
+	Owner               m_veh_owner;     ///< owner of the vehicle
+	TileIndex           m_old_tile;      ///< the origin (vehicle moved from) before move
+	Trackdir            m_old_td;        ///< the trackdir (the vehicle was on) before move
+	TileIndex           m_new_tile;      ///< the new tile (the vehicle has entered)
+	TrackdirBits        m_new_td_bits;   ///< the new set of available trackdirs
+	DiagDirection       m_exitdir;       ///< exit direction (leaving the old tile)
+	bool                m_is_tunnel;     ///< last turn passed tunnel
+	bool                m_is_bridge;     ///< last turn passed bridge ramp
+	bool                m_is_station;    ///< last turn passed station
+	int                 m_tiles_skipped; ///< number of skipped tunnel or station tiles
+	ErrorCode           m_err;
+	CPerformanceTimer  *m_pPerf;
+	RailTypes           m_railtypes;
+
+	FORCEINLINE CFollowTrackT(const VehicleType *v = NULL, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
+	{
+		Init(v, railtype_override, pPerf);
+	}
+
+	FORCEINLINE CFollowTrackT(Owner o, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
+	{
+		m_veh = NULL;
+		Init(o, railtype_override, pPerf);
+	}
+
+	FORCEINLINE void Init(const VehicleType *v, RailTypes railtype_override, CPerformanceTimer *pPerf)
+	{
+		assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
+		m_veh = v;
+		Init(v != NULL ? v->owner : INVALID_OWNER, IsRailTT() && railtype_override == INVALID_RAILTYPES ? Train::From(v)->compatible_railtypes : railtype_override, pPerf);
+	}
+
+	FORCEINLINE void Init(Owner o, RailTypes railtype_override, CPerformanceTimer *pPerf)
+	{
+		assert((!IsRoadTT() || m_veh != NULL) && (!IsRailTT() || railtype_override != INVALID_RAILTYPES));
+		m_veh_owner = o;
+		m_pPerf = pPerf;
+		/* don't worry, all is inlined so compiler should remove unnecessary initializations */
+		m_new_tile = INVALID_TILE;
+		m_new_td_bits = TRACKDIR_BIT_NONE;
+		m_exitdir = INVALID_DIAGDIR;
+		m_is_station = m_is_bridge = m_is_tunnel = false;
+		m_tiles_skipped = 0;
+		m_err = EC_NONE;
+		m_railtypes = railtype_override;
+	}
+
+	FORCEINLINE static TransportType TT() {return Ttr_type_;}
+	FORCEINLINE static bool IsWaterTT() {return TT() == TRANSPORT_WATER;}
+	FORCEINLINE static bool IsRailTT() {return TT() == TRANSPORT_RAIL;}
+	FORCEINLINE bool IsTram() {return IsRoadTT() && HasBit(RoadVehicle::From(m_veh)->compatible_roadtypes, ROADTYPE_TRAM);}
+	FORCEINLINE static bool IsRoadTT() {return TT() == TRANSPORT_ROAD;}
+	FORCEINLINE static bool Allow90degTurns() {return T90deg_turns_allowed_;}
+	FORCEINLINE static bool DoTrackMasking() {return IsRailTT() && Tmask_reserved_tracks;}
+
+	/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
+	FORCEINLINE DiagDirection GetSingleTramBit(TileIndex tile)
+	{
+		assert(IsTram()); // this function shouldn't be called in other cases
+
+		if (IsNormalRoadTile(tile)) {
+			RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
+			switch (rb) {
+				case ROAD_NW: return DIAGDIR_NW;
+				case ROAD_SW: return DIAGDIR_SW;
+				case ROAD_SE: return DIAGDIR_SE;
+				case ROAD_NE: return DIAGDIR_NE;
+				default: break;
+			}
+		}
+		return INVALID_DIAGDIR;
+	}
+
+	/** main follower routine. Fills all members and return true on success.
+	 *  Otherwise returns false if track can't be followed. */
+	inline bool Follow(TileIndex old_tile, Trackdir old_td)
+	{
+		m_old_tile = old_tile;
+		m_old_td = old_td;
+		m_err = EC_NONE;
+		assert(((TrackStatusToTrackdirBits(GetTileTrackStatus(m_old_tile, TT(), IsRoadTT() && m_veh != NULL ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0)) & TrackdirToTrackdirBits(m_old_td)) != 0) ||
+		       (IsTram() && GetSingleTramBit(m_old_tile) != INVALID_DIAGDIR)); // Disable the assertion for single tram bits
+		m_exitdir = TrackdirToExitdir(m_old_td);
+		if (ForcedReverse()) return true;
+		if (!CanExitOldTile()) return false;
+		FollowTileExit();
+		if (!QueryNewTileTrackStatus()) return TryReverse();
+		if (!CanEnterNewTile()) return false;
+		m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
+		if (m_new_td_bits == TRACKDIR_BIT_NONE) {
+			m_err = EC_NO_WAY;
+			return false;
+		}
+		if (!Allow90degTurns()) {
+			m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
+			if (m_new_td_bits == TRACKDIR_BIT_NONE) {
+				m_err = EC_90DEG;
+				return false;
+			}
+		}
+		return true;
+	}
+
+	inline bool MaskReservedTracks()
+	{
+		if (!DoTrackMasking()) return true;
+
+		if (m_is_station) {
+			/* Check skipped station tiles as well. */
+			TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
+			for (TileIndex tile = m_new_tile - diff * m_tiles_skipped; tile != m_new_tile; tile += diff) {
+				if (HasStationReservation(tile)) {
+					m_new_td_bits = TRACKDIR_BIT_NONE;
+					m_err = EC_RESERVED;
+					return false;
+				}
+			}
+		}
+
+		TrackBits reserved = GetReservedTrackbits(m_new_tile);
+		/* Mask already reserved trackdirs. */
+		m_new_td_bits &= ~TrackBitsToTrackdirBits(reserved);
+		/* Mask out all trackdirs that conflict with the reservation. */
+		uint bits = (uint)TrackdirBitsToTrackBits(m_new_td_bits);
+		int i;
+		FOR_EACH_SET_BIT(i, bits) {
+			if (TracksOverlap(reserved | TrackToTrackBits((Track)i))) m_new_td_bits &= ~TrackToTrackdirBits((Track)i);
+		}
+		if (m_new_td_bits == TRACKDIR_BIT_NONE) {
+			m_err = EC_RESERVED;
+			return false;
+		}
+		return true;
+	}
+
+protected:
+	/** Follow the m_exitdir from m_old_tile and fill m_new_tile and m_tiles_skipped */
+	FORCEINLINE void FollowTileExit()
+	{
+		m_is_station = m_is_bridge = m_is_tunnel = false;
+		m_tiles_skipped = 0;
+
+		/* extra handling for tunnels and bridges in our direction */
+		if (IsTileType(m_old_tile, MP_TUNNELBRIDGE)) {
+			DiagDirection enterdir = GetTunnelBridgeDirection(m_old_tile);
+			if (enterdir == m_exitdir) {
+				/* we are entering the tunnel / bridge */
+				if (IsTunnel(m_old_tile)) {
+					m_is_tunnel = true;
+					m_new_tile = GetOtherTunnelEnd(m_old_tile);
+				} else { // IsBridge(m_old_tile)
+					m_is_bridge = true;
+					m_new_tile = GetOtherBridgeEnd(m_old_tile);
+				}
+				m_tiles_skipped = GetTunnelBridgeLength(m_new_tile, m_old_tile);
+				return;
+			}
+			assert(ReverseDiagDir(enterdir) == m_exitdir);
+		}
+
+		/* normal or station tile, do one step */
+		TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
+		m_new_tile = TILE_ADD(m_old_tile, diff);
+
+		/* special handling for stations */
+		if (IsRailTT() && HasStationTileRail(m_new_tile)) {
+			m_is_station = true;
+		} else if (IsRoadTT() && IsRoadStopTile(m_new_tile)) {
+			m_is_station = true;
+		} else {
+			m_is_station = false;
+		}
+	}
+
+	/** stores track status (available trackdirs) for the new tile into m_new_td_bits */
+	FORCEINLINE bool QueryNewTileTrackStatus()
+	{
+		CPerfStart perf(*m_pPerf);
+		if (IsRailTT() && IsPlainRailTile(m_new_tile)) {
+			m_new_td_bits = (TrackdirBits)(GetTrackBits(m_new_tile) * 0x101);
+		} else {
+			m_new_td_bits = TrackStatusToTrackdirBits(GetTileTrackStatus(m_new_tile, TT(), IsRoadTT() && m_veh != NULL ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0));
+
+			if (IsTram() && m_new_td_bits == 0) {
+				/* GetTileTrackStatus() returns 0 for single tram bits.
+				 * As we cannot change it there (easily) without breaking something, change it here */
+				switch (GetSingleTramBit(m_new_tile)) {
+					case DIAGDIR_NE:
+					case DIAGDIR_SW:
+						m_new_td_bits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
+						break;
+
+					case DIAGDIR_NW:
+					case DIAGDIR_SE:
+						m_new_td_bits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
+						break;
+
+					default: break;
+				}
+			}
+		}
+		return (m_new_td_bits != TRACKDIR_BIT_NONE);
+	}
+
+	/** return true if we can leave m_old_tile in m_exitdir */
+	FORCEINLINE bool CanExitOldTile()
+	{
+		/* road stop can be left at one direction only unless it's a drive-through stop */
+		if (IsRoadTT() && IsStandardRoadStopTile(m_old_tile)) {
+			DiagDirection exitdir = GetRoadStopDir(m_old_tile);
+			if (exitdir != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+
+		/* single tram bits can only be left in one direction */
+		if (IsTram()) {
+			DiagDirection single_tram = GetSingleTramBit(m_old_tile);
+			if (single_tram != INVALID_DIAGDIR && single_tram != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+
+		/* road depots can be also left in one direction only */
+		if (IsRoadTT() && IsDepotTypeTile(m_old_tile, TT())) {
+			DiagDirection exitdir = GetRoadDepotDirection(m_old_tile);
+			if (exitdir != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+		return true;
+	}
+
+	/** return true if we can enter m_new_tile from m_exitdir */
+	FORCEINLINE bool CanEnterNewTile()
+	{
+		if (IsRoadTT() && IsStandardRoadStopTile(m_new_tile)) {
+			/* road stop can be entered from one direction only unless it's a drive-through stop */
+			DiagDirection exitdir = GetRoadStopDir(m_new_tile);
+			if (ReverseDiagDir(exitdir) != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+
+		/* single tram bits can only be entered from one direction */
+		if (IsTram()) {
+			DiagDirection single_tram = GetSingleTramBit(m_new_tile);
+			if (single_tram != INVALID_DIAGDIR && single_tram != ReverseDiagDir(m_exitdir)) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+
+		/* road and rail depots can also be entered from one direction only */
+		if (IsRoadTT() && IsDepotTypeTile(m_new_tile, TT())) {
+			DiagDirection exitdir = GetRoadDepotDirection(m_new_tile);
+			if (ReverseDiagDir(exitdir) != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+			/* don't try to enter other company's depots */
+			if (GetTileOwner(m_new_tile) != m_veh_owner) {
+				m_err = EC_OWNER;
+				return false;
+			}
+		}
+		if (IsRailTT() && IsDepotTypeTile(m_new_tile, TT())) {
+			DiagDirection exitdir = GetRailDepotDirection(m_new_tile);
+			if (ReverseDiagDir(exitdir) != m_exitdir) {
+				m_err = EC_NO_WAY;
+				return false;
+			}
+		}
+
+		/* rail transport is possible only on tiles with the same owner as vehicle */
+		if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh_owner) {
+			/* different owner */
+			m_err = EC_NO_WAY;
+			return false;
+		}
+
+		/* rail transport is possible only on compatible rail types */
+		if (IsRailTT()) {
+			RailType rail_type = GetTileRailType(m_new_tile);
+			if (!HasBit(m_railtypes, rail_type)) {
+				/* incompatible rail type */
+				m_err = EC_RAIL_TYPE;
+				return false;
+			}
+		}
+
+		/* tunnel holes and bridge ramps can be entered only from proper direction */
+		if (IsTileType(m_new_tile, MP_TUNNELBRIDGE)) {
+			if (IsTunnel(m_new_tile)) {
+				if (!m_is_tunnel) {
+					DiagDirection tunnel_enterdir = GetTunnelBridgeDirection(m_new_tile);
+					if (tunnel_enterdir != m_exitdir) {
+						m_err = EC_NO_WAY;
+						return false;
+					}
+				}
+			} else { // IsBridge(m_new_tile)
+				if (!m_is_bridge) {
+					DiagDirection ramp_enderdir = GetTunnelBridgeDirection(m_new_tile);
+					if (ramp_enderdir != m_exitdir) {
+						m_err = EC_NO_WAY;
+						return false;
+					}
+				}
+			}
+		}
+
+		/* special handling for rail stations - get to the end of platform */
+		if (IsRailTT() && m_is_station) {
+			/* entered railway station
+			 * get platform length */
+			uint length = BaseStation::GetByTile(m_new_tile)->GetPlatformLength(m_new_tile, TrackdirToExitdir(m_old_td));
+			/* how big step we must do to get to the last platform tile; */
+			m_tiles_skipped = length - 1;
+			/* move to the platform end */
+			TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
+			diff *= m_tiles_skipped;
+			m_new_tile = TILE_ADD(m_new_tile, diff);
+			return true;
+		}
+
+		return true;
+	}
+
+	/** return true if we must reverse (in depots and single tram bits) */
+	FORCEINLINE bool ForcedReverse()
+	{
+		/* rail and road depots cause reversing */
+		if (!IsWaterTT() && IsDepotTypeTile(m_old_tile, TT())) {
+			DiagDirection exitdir = IsRailTT() ? GetRailDepotDirection(m_old_tile) : GetRoadDepotDirection(m_old_tile);
+			if (exitdir != m_exitdir) {
+				/* reverse */
+				m_new_tile = m_old_tile;
+				m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
+				m_exitdir = exitdir;
+				m_tiles_skipped = 0;
+				m_is_tunnel = m_is_bridge = m_is_station = false;
+				return true;
+			}
+		}
+
+		/* single tram bits cause reversing */
+		if (IsTram() && GetSingleTramBit(m_old_tile) == ReverseDiagDir(m_exitdir)) {
+			/* reverse */
+			m_new_tile = m_old_tile;
+			m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
+			m_exitdir = ReverseDiagDir(m_exitdir);
+			m_tiles_skipped = 0;
+			m_is_tunnel = m_is_bridge = m_is_station = false;
+			return true;
+		}
+
+		return false;
+	}
+
+	/** return true if we successfully reversed at end of road/track */
+	FORCEINLINE bool TryReverse()
+	{
+		if (IsRoadTT() && !IsTram()) {
+			/* if we reached the end of road, we can reverse the RV and continue moving */
+			m_exitdir = ReverseDiagDir(m_exitdir);
+			/* new tile will be the same as old one */
+			m_new_tile = m_old_tile;
+			/* set new trackdir bits to all reachable trackdirs */
+			QueryNewTileTrackStatus();
+			m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
+			if (m_new_td_bits != TRACKDIR_BIT_NONE) {
+				/* we have some trackdirs reachable after reversal */
+				return true;
+			}
+		}
+		m_err = EC_NO_WAY;
+		return false;
+	}
+
+public:
+	/** Helper for pathfinders - get min/max speed on the m_old_tile/m_old_td */
+	int GetSpeedLimit(int *pmin_speed = NULL) const
+	{
+		int min_speed = 0;
+		int max_speed = INT_MAX; // no limit
+
+		/* for now we handle only on-bridge speed limit */
+		if (!IsWaterTT() && IsBridgeTile(m_old_tile)) {
+			int spd = GetBridgeSpec(GetBridgeType(m_old_tile))->speed;
+			if (IsRoadTT()) spd *= 2;
+			if (max_speed > spd) max_speed = spd;
+		}
+
+		/* if min speed was requested, return it */
+		if (pmin_speed) *pmin_speed = min_speed;
+		return max_speed;
+	}
+};
+
+typedef CFollowTrackT<TRANSPORT_WATER, Ship,        true > CFollowTrackWater;
+typedef CFollowTrackT<TRANSPORT_ROAD,  RoadVehicle, true > CFollowTrackRoad;
+typedef CFollowTrackT<TRANSPORT_RAIL,  Train,       true > CFollowTrackRail;
+
+typedef CFollowTrackT<TRANSPORT_WATER, Ship,        false> CFollowTrackWaterNo90;
+typedef CFollowTrackT<TRANSPORT_ROAD,  RoadVehicle, false> CFollowTrackRoadNo90;
+typedef CFollowTrackT<TRANSPORT_RAIL,  Train,       false> CFollowTrackRailNo90;
+
+typedef CFollowTrackT<TRANSPORT_RAIL, Train, true,  true > CFollowTrackFreeRail;
+typedef CFollowTrackT<TRANSPORT_RAIL, Train, false, true > CFollowTrackFreeRailNo90;
+
+#endif /* FOLLOW_TRACK_HPP */