KUDr@3900: /* $Id$ */
KUDr@3900: 
celestar@6121: /** @file follow_track.hpp Template function for track followers */
celestar@6121: 
KUDr@3900: #ifndef  FOLLOW_TRACK_HPP
KUDr@3900: #define  FOLLOW_TRACK_HPP
KUDr@3900: 
KUDr@3900: #include "yapf.hpp"
rubidium@8962: #include "../depot_map.h"
KUDr@8636: 
KUDr@3900: /** Track follower helper template class (can serve pathfinders and vehicle
rubidium@4549:  *  controllers). See 6 different typedefs below for 3 different transport
rubidium@4549:  *  types w/ of w/o 90-deg turns allowed */
KUDr@3900: template <TransportType Ttr_type_, bool T90deg_turns_allowed_ = true>
KUDr@8636: struct CFollowTrackT
KUDr@3900: {
KUDr@8636: 	enum ErrorCode {
KUDr@8636: 		EC_NONE,
KUDr@8636: 		EC_OWNER,
KUDr@8636: 		EC_RAIL_TYPE,
KUDr@8636: 		EC_90DEG,
KUDr@8636: 		EC_NO_WAY,
KUDr@8636: 	};
KUDr@8636: 
rubidium@9439: 	const Vehicle      *m_veh;           ///< moving vehicle
KUDr@8636: 	TileIndex           m_old_tile;      ///< the origin (vehicle moved from) before move
KUDr@8636: 	Trackdir            m_old_td;        ///< the trackdir (the vehicle was on) before move
KUDr@8636: 	TileIndex           m_new_tile;      ///< the new tile (the vehicle has entered)
KUDr@8636: 	TrackdirBits        m_new_td_bits;   ///< the new set of available trackdirs
KUDr@8636: 	DiagDirection       m_exitdir;       ///< exit direction (leaving the old tile)
KUDr@8636: 	bool                m_is_tunnel;     ///< last turn passed tunnel
KUDr@8636: 	bool                m_is_bridge;     ///< last turn passed bridge ramp
KUDr@8636: 	bool                m_is_station;    ///< last turn passed station
KUDr@8636: 	int                 m_tiles_skipped; ///< number of skipped tunnel or station tiles
KUDr@8636: 	ErrorCode           m_err;
rubidium@9439: 	CPerformanceTimer  *m_pPerf;
rubidium@9797: 	RailTypes           m_railtypes;
KUDr@3900: 
rubidium@9797: 	FORCEINLINE CFollowTrackT(const Vehicle *v = NULL, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
KUDr@3900: 	{
rubidium@9797: 		Init(v, railtype_override, pPerf);
KUDr@3900: 	}
KUDr@3900: 
rubidium@9797: 	FORCEINLINE void Init(const Vehicle *v, RailTypes railtype_override, CPerformanceTimer *pPerf)
KUDr@3900: 	{
rubidium@6259: 		assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
KUDr@3900: 		m_veh = v;
KUDr@3900: 		m_pPerf = pPerf;
KUDr@3900: 		// don't worry, all is inlined so compiler should remove unnecessary initializations
KUDr@3900: 		m_new_tile = INVALID_TILE;
KUDr@3900: 		m_new_td_bits = TRACKDIR_BIT_NONE;
KUDr@3900: 		m_exitdir = INVALID_DIAGDIR;
celestar@5385: 		m_is_station = m_is_bridge = m_is_tunnel = false;
KUDr@3931: 		m_tiles_skipped = 0;
KUDr@7211: 		m_err = EC_NONE;
rubidium@9797: 		if (IsRailTT()) m_railtypes = railtype_override == INVALID_RAILTYPES ? v->u.rail.compatible_railtypes : railtype_override;
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	FORCEINLINE static TransportType TT() {return Ttr_type_;}
KUDr@3900: 	FORCEINLINE static bool IsWaterTT() {return TT() == TRANSPORT_WATER;}
KUDr@3900: 	FORCEINLINE static bool IsRailTT() {return TT() == TRANSPORT_RAIL;}
frosch@8465: 	FORCEINLINE bool IsTram() {return IsRoadTT() && HasBit(m_veh->u.road.compatible_roadtypes, ROADTYPE_TRAM);}
KUDr@3900: 	FORCEINLINE static bool IsRoadTT() {return TT() == TRANSPORT_ROAD;}
KUDr@3900: 	FORCEINLINE static bool Allow90degTurns() {return T90deg_turns_allowed_;}
KUDr@3900: 
frosch@8465: 	/** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */
frosch@8465: 	FORCEINLINE DiagDirection GetSingleTramBit(TileIndex tile)
frosch@8465: 	{
frosch@8563: 		if (IsTram() && IsNormalRoadTile(tile)) {
frosch@8465: 			RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
frosch@8465: 			switch (rb) {
frosch@8465: 				case ROAD_NW: return DIAGDIR_NW;
frosch@8465: 				case ROAD_SW: return DIAGDIR_SW;
frosch@8465: 				case ROAD_SE: return DIAGDIR_SE;
frosch@8465: 				case ROAD_NE: return DIAGDIR_NE;
frosch@8465: 				default: break;
frosch@8465: 			}
frosch@8465: 		}
frosch@8465: 		return INVALID_DIAGDIR;
frosch@8465: 	}
frosch@8465: 
KUDr@3900: 	/** main follower routine. Fills all members and return true on success.
rubidium@4549: 	 *  Otherwise returns false if track can't be followed. */
rubidium@9797: 	inline bool Follow(TileIndex old_tile, Trackdir old_td)
KUDr@3900: 	{
KUDr@3900: 		m_old_tile = old_tile;
KUDr@3900: 		m_old_td = old_td;
KUDr@7211: 		m_err = EC_NONE;
frosch@8616: 		assert(((TrackStatusToTrackdirBits(GetTileTrackStatus(m_old_tile, TT(), m_veh->u.road.compatible_roadtypes)) & TrackdirToTrackdirBits(m_old_td)) != 0) ||
frosch@8465: 		       (GetSingleTramBit(m_old_tile) != INVALID_DIAGDIR)); // Disable the assertion for single tram bits
KUDr@3900: 		m_exitdir = TrackdirToExitdir(m_old_td);
frosch@8465: 		if (ForcedReverse()) return true;
KUDr@3900: 		if (!CanExitOldTile()) return false;
KUDr@3900: 		FollowTileExit();
KUDr@3976: 		if (!QueryNewTileTrackStatus()) return TryReverse();
KUDr@3900: 		if (!CanEnterNewTile()) return false;
KUDr@3900: 		m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
KUDr@7211: 		if (m_new_td_bits == TRACKDIR_BIT_NONE) {
KUDr@7211: 			m_err = EC_NO_WAY;
KUDr@7211: 			return false;
KUDr@7211: 		}
KUDr@7211: 		if (!Allow90degTurns()) {
KUDr@3900: 			m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
KUDr@7211: 			if (m_new_td_bits == TRACKDIR_BIT_NONE) {
KUDr@7211: 				m_err = EC_90DEG;
KUDr@7211: 				return false;
KUDr@7211: 			}
KUDr@7211: 		}
KUDr@7211: 		return true;
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: protected:
KUDr@3931: 	/** Follow the m_exitdir from m_old_tile and fill m_new_tile and m_tiles_skipped */
KUDr@3900: 	FORCEINLINE void FollowTileExit()
KUDr@3900: 	{
celestar@5385: 		m_is_station = m_is_bridge = m_is_tunnel = false;
celestar@5385: 		m_tiles_skipped = 0;
celestar@5385: 
smatz@8398: 		// extra handling for tunnels and bridges in our direction
smatz@8398: 		if (IsTileType(m_old_tile, MP_TUNNELBRIDGE)) {
smatz@8398: 			DiagDirection enterdir = GetTunnelBridgeDirection(m_old_tile);
smatz@8398: 			if (enterdir == m_exitdir) {
smatz@8398: 				// we are entering the tunnel / bridge
smatz@8398: 				if (IsTunnel(m_old_tile)) {
smatz@8398: 					m_is_tunnel = true;
smatz@8398: 					m_new_tile = GetOtherTunnelEnd(m_old_tile);
smatz@8398: 				} else { // IsBridge(m_old_tile)
smatz@8398: 					m_is_bridge = true;
smatz@8398: 					m_new_tile = GetOtherBridgeEnd(m_old_tile);
smatz@8398: 				}
smatz@8398: 				m_tiles_skipped = GetTunnelBridgeLength(m_new_tile, m_old_tile);
KUDr@3900: 				return;
KUDr@3900: 			}
smatz@8398: 			assert(ReverseDiagDir(enterdir) == m_exitdir);
celestar@5385: 		}
celestar@5385: 
celestar@5385: 		// normal or station tile, do one step
Darkvater@4559: 		TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
KUDr@3900: 		m_new_tile = TILE_ADD(m_old_tile, diff);
KUDr@3931: 
KUDr@3931: 		// special handling for stations
KUDr@3931: 		if (IsRailTT() && IsRailwayStationTile(m_new_tile)) {
KUDr@3931: 			m_is_station = true;
KUDr@3931: 		} else if (IsRoadTT() && IsRoadStopTile(m_new_tile)) {
KUDr@3931: 			m_is_station = true;
KUDr@3931: 		} else {
KUDr@3931: 			m_is_station = false;
KUDr@3931: 		}
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	/** stores track status (available trackdirs) for the new tile into m_new_td_bits */
KUDr@3900: 	FORCEINLINE bool QueryNewTileTrackStatus()
KUDr@3900: 	{
KUDr@3900: 		CPerfStart perf(*m_pPerf);
KUDr@3912: 		if (IsRailTT() && GetTileType(m_new_tile) == MP_RAILWAY && IsPlainRailTile(m_new_tile)) {
KUDr@3900: 			m_new_td_bits = (TrackdirBits)(GetTrackBits(m_new_tile) * 0x101);
KUDr@3900: 		} else {
frosch@8616: 			m_new_td_bits = TrackStatusToTrackdirBits(GetTileTrackStatus(m_new_tile, TT(), m_veh->u.road.compatible_roadtypes));
frosch@8465: 
frosch@8465: 			if (m_new_td_bits == 0) {
frosch@8465: 				/* GetTileTrackStatus() returns 0 for single tram bits.
frosch@8465: 				 * As we cannot change it there (easily) without breaking something, change it here */
frosch@8465: 				switch (GetSingleTramBit(m_new_tile)) {
frosch@8465: 					case DIAGDIR_NE:
frosch@8465: 					case DIAGDIR_SW:
frosch@8465: 						m_new_td_bits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
frosch@8465: 						break;
frosch@8465: 
frosch@8465: 					case DIAGDIR_NW:
frosch@8465: 					case DIAGDIR_SE:
frosch@8465: 						m_new_td_bits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
frosch@8465: 						break;
frosch@8465: 
frosch@8465: 					default: break;
frosch@8465: 				}
frosch@8465: 			}
KUDr@3900: 		}
KUDr@3900: 		return (m_new_td_bits != TRACKDIR_BIT_NONE);
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	/** return true if we can leave m_old_tile in m_exitdir */
KUDr@3900: 	FORCEINLINE bool CanExitOldTile()
KUDr@3900: 	{
rubidium@6012: 		// road stop can be left at one direction only unless it's a drive-through stop
rubidium@6012: 		if (IsRoadTT() && IsStandardRoadStopTile(m_old_tile)) {
KUDr@3900: 			DiagDirection exitdir = GetRoadStopDir(m_old_tile);
KUDr@7211: 			if (exitdir != m_exitdir) {
KUDr@7211: 				m_err = EC_NO_WAY;
KUDr@3900: 				return false;
KUDr@7211: 			}
KUDr@3900: 		}
KUDr@3900: 
frosch@8465: 		/* single tram bits can only be left in one direction */
frosch@8465: 		DiagDirection single_tram = GetSingleTramBit(m_old_tile);
frosch@8465: 		if (single_tram != INVALID_DIAGDIR && single_tram != m_exitdir) {
frosch@8465: 			m_err = EC_NO_WAY;
frosch@8465: 			return false;
frosch@8465: 		}
frosch@8465: 
KUDr@3900: 		// road depots can be also left in one direction only
smatz@8954: 		if (IsRoadTT() && IsDepotTypeTile(m_old_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRoadDepotDirection(m_old_tile);
KUDr@7211: 			if (exitdir != m_exitdir) {
KUDr@7211: 				m_err = EC_NO_WAY;
KUDr@3900: 				return false;
KUDr@7211: 			}
KUDr@3900: 		}
KUDr@3900: 		return true;
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	/** return true if we can enter m_new_tile from m_exitdir */
KUDr@3900: 	FORCEINLINE bool CanEnterNewTile()
KUDr@3900: 	{
rubidium@6012: 		if (IsRoadTT() && IsStandardRoadStopTile(m_new_tile)) {
rubidium@6012: 			// road stop can be entered from one direction only unless it's a drive-through stop
KUDr@3900: 			DiagDirection exitdir = GetRoadStopDir(m_new_tile);
KUDr@7211: 			if (ReverseDiagDir(exitdir) != m_exitdir) {
KUDr@7211: 				m_err = EC_NO_WAY;
KUDr@3900: 				return false;
KUDr@7211: 			}
KUDr@3900: 		}
KUDr@3900: 
frosch@8465: 		/* single tram bits can only be entered from one direction */
frosch@8465: 		DiagDirection single_tram = GetSingleTramBit(m_new_tile);
frosch@8465: 		if (single_tram != INVALID_DIAGDIR && single_tram != ReverseDiagDir(m_exitdir)) {
frosch@8465: 			m_err = EC_NO_WAY;
frosch@8465: 			return false;
frosch@8465: 		}
frosch@8465: 
KUDr@3900: 		// road and rail depots can also be entered from one direction only
smatz@8954: 		if (IsRoadTT() && IsDepotTypeTile(m_new_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRoadDepotDirection(m_new_tile);
KUDr@7211: 			if (ReverseDiagDir(exitdir) != m_exitdir) {
KUDr@7211: 				m_err = EC_NO_WAY;
KUDr@3900: 				return false;
KUDr@7211: 			}
KUDr@4407: 			// don't try to enter other player's depots
KUDr@4407: 			if (GetTileOwner(m_new_tile) != m_veh->owner) {
KUDr@7211: 				m_err = EC_OWNER;
KUDr@4407: 				return false;
KUDr@4407: 			}
KUDr@3900: 		}
smatz@8954: 		if (IsRailTT() && IsDepotTypeTile(m_new_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRailDepotDirection(m_new_tile);
KUDr@7211: 			if (ReverseDiagDir(exitdir) != m_exitdir) {
KUDr@7211: 				m_err = EC_NO_WAY;
KUDr@3900: 				return false;
KUDr@7211: 			}
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// rail transport is possible only on tiles with the same owner as vehicle
KUDr@3900: 		if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh->owner) {
KUDr@3900: 			// different owner
KUDr@7211: 			m_err = EC_NO_WAY;
celestar@5385: 			return false;
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// rail transport is possible only on compatible rail types
KUDr@3900: 		if (IsRailTT()) {
tron@6154: 			RailType rail_type = GetTileRailType(m_new_tile);
rubidium@9797: 			if (!HasBit(m_railtypes, rail_type)) {
KUDr@3900: 				// incompatible rail type
KUDr@7211: 				m_err = EC_RAIL_TYPE;
KUDr@3900: 				return false;
KUDr@3900: 			}
KUDr@3900: 		}
KUDr@3900: 
KUDr@5420: 		// tunnel holes and bridge ramps can be entered only from proper direction
rubidium@9490: 		if (IsTileType(m_new_tile, MP_TUNNELBRIDGE)) {
KUDr@5420: 			if (IsTunnel(m_new_tile)) {
KUDr@5420: 				if (!m_is_tunnel) {
smatz@8083: 					DiagDirection tunnel_enterdir = GetTunnelBridgeDirection(m_new_tile);
KUDr@7211: 					if (tunnel_enterdir != m_exitdir) {
KUDr@7214: 						m_err = EC_NO_WAY;
KUDr@7211: 						return false;
KUDr@7211: 					}
KUDr@5420: 				}
smatz@8390: 			} else { // IsBridge(m_new_tile)
KUDr@5420: 				if (!m_is_bridge) {
smatz@8083: 					DiagDirection ramp_enderdir = GetTunnelBridgeDirection(m_new_tile);
KUDr@7211: 					if (ramp_enderdir != m_exitdir) {
KUDr@7214: 						m_err = EC_NO_WAY;
KUDr@7211: 						return false;
KUDr@7211: 					}
KUDr@5420: 				}
KUDr@5420: 			}
KUDr@3900: 		}
KUDr@3931: 
KUDr@3931: 		// special handling for rail stations - get to the end of platform
KUDr@3931: 		if (IsRailTT() && m_is_station) {
KUDr@3931: 			// entered railway station
KUDr@3931: 			// get platform length
celestar@5998: 			uint length = GetStationByTile(m_new_tile)->GetPlatformLength(m_new_tile, TrackdirToExitdir(m_old_td));
KUDr@3931: 			// how big step we must do to get to the last platform tile;
KUDr@3931: 			m_tiles_skipped = length - 1;
KUDr@3931: 			// move to the platform end
Darkvater@4559: 			TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
KUDr@3931: 			diff *= m_tiles_skipped;
KUDr@3931: 			m_new_tile = TILE_ADD(m_new_tile, diff);
KUDr@3931: 			return true;
KUDr@3931: 		}
KUDr@3931: 
KUDr@3900: 		return true;
KUDr@3900: 	}
KUDr@3900: 
frosch@8465: 	/** return true if we must reverse (in depots and single tram bits) */
frosch@8465: 	FORCEINLINE bool ForcedReverse()
KUDr@3900: 	{
KUDr@3976: 		// rail and road depots cause reversing
smatz@8954: 		if (!IsWaterTT() && IsDepotTypeTile(m_old_tile, TT())) {
KUDr@3976: 			DiagDirection exitdir = IsRailTT() ? GetRailDepotDirection(m_old_tile) : GetRoadDepotDirection(m_old_tile);
KUDr@3900: 			if (exitdir != m_exitdir) {
KUDr@3900: 				// reverse
KUDr@3900: 				m_new_tile = m_old_tile;
KUDr@3900: 				m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
KUDr@3900: 				m_exitdir = exitdir;
KUDr@3931: 				m_tiles_skipped = 0;
celestar@5385: 				m_is_tunnel = m_is_bridge = m_is_station = false;
KUDr@3900: 				return true;
KUDr@3900: 			}
KUDr@3900: 		}
frosch@8465: 
frosch@8465: 		// single tram bits cause reversing
frosch@8465: 		if (GetSingleTramBit(m_old_tile) == ReverseDiagDir(m_exitdir)) {
frosch@8465: 			// reverse
frosch@8465: 			m_new_tile = m_old_tile;
frosch@8465: 			m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
frosch@8465: 			m_exitdir = ReverseDiagDir(m_exitdir);
frosch@8465: 			m_tiles_skipped = 0;
frosch@8465: 			m_is_tunnel = m_is_bridge = m_is_station = false;
frosch@8465: 			return true;
frosch@8465: 		}
frosch@8465: 
KUDr@3900: 		return false;
KUDr@3900: 	}
KUDr@3976: 
KUDr@3976: 	/** return true if we successfully reversed at end of road/track */
KUDr@3976: 	FORCEINLINE bool TryReverse()
KUDr@3976: 	{
frosch@8465: 		if (IsRoadTT() && !IsTram()) {
KUDr@3976: 			// if we reached the end of road, we can reverse the RV and continue moving
KUDr@3976: 			m_exitdir = ReverseDiagDir(m_exitdir);
KUDr@3976: 			// new tile will be the same as old one
KUDr@3976: 			m_new_tile = m_old_tile;
KUDr@3976: 			// set new trackdir bits to all reachable trackdirs
KUDr@3976: 			QueryNewTileTrackStatus();
KUDr@3976: 			m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
KUDr@3976: 			if (m_new_td_bits != TRACKDIR_BIT_NONE) {
KUDr@3976: 				// we have some trackdirs reachable after reversal
KUDr@3976: 				return true;
KUDr@3976: 			}
KUDr@3976: 		}
KUDr@7211: 		m_err = EC_NO_WAY;
KUDr@3976: 		return false;
KUDr@3976: 	}
KUDr@3976: 
KUDr@3900: public:
KUDr@3900: 	/** Helper for pathfinders - get min/max speed on the m_old_tile/m_old_td */
KUDr@7037: 	int GetSpeedLimit(int *pmin_speed = NULL) const
KUDr@3900: 	{
KUDr@3900: 		int min_speed = 0;
KUDr@3900: 		int max_speed = INT_MAX; // no limit
KUDr@3900: 
KUDr@3900: 		// for now we handle only on-bridge speed limit
celestar@5385: 		if (!IsWaterTT() && IsBridgeTile(m_old_tile)) {
belugas@8491: 			int spd = GetBridgeSpec(GetBridgeType(m_old_tile))->speed;
celestar@5385: 			if (IsRoadTT()) spd *= 2;
celestar@5385: 			if (max_speed > spd) max_speed = spd;
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// if min speed was requested, return it
KUDr@3900: 		if (pmin_speed) *pmin_speed = min_speed;
KUDr@3900: 		return max_speed;
KUDr@3900: 	}
KUDr@3900: };
KUDr@3900: 
KUDr@3900: typedef CFollowTrackT<TRANSPORT_WATER, true > CFollowTrackWater;
KUDr@3900: typedef CFollowTrackT<TRANSPORT_ROAD , true > CFollowTrackRoad;
KUDr@3900: typedef CFollowTrackT<TRANSPORT_RAIL , true > CFollowTrackRail;
KUDr@3900: 
KUDr@3900: typedef CFollowTrackT<TRANSPORT_WATER, false> CFollowTrackWaterNo90;
KUDr@3900: typedef CFollowTrackT<TRANSPORT_ROAD , false> CFollowTrackRoadNo90;
KUDr@3900: typedef CFollowTrackT<TRANSPORT_RAIL , false> CFollowTrackRailNo90;
KUDr@3900: 
KUDr@3900: #endif /* FOLLOW_TRACK_HPP */