KUDr@3900: /* $Id$ */
KUDr@3900: 
KUDr@3900: #ifndef  FOLLOW_TRACK_HPP
KUDr@3900: #define  FOLLOW_TRACK_HPP
KUDr@3900: 
KUDr@3900: #include "yapf.hpp"
KUDr@3900: 
KUDr@3900: /** Track follower helper template class (can serve pathfinders and vehicle
KUDr@3900:     controllers). See 6 different typedefs below for 3 different transport
KUDr@3900:     types w/ of w/o 90-deg turns allowed */
KUDr@3900: template <TransportType Ttr_type_, bool T90deg_turns_allowed_ = true>
KUDr@3900: struct CFollowTrackT : public FollowTrack_t
KUDr@3900: {
KUDr@3900: 	CPerformanceTimer* m_pPerf;
KUDr@3900: 
KUDr@3900: 	FORCEINLINE CFollowTrackT(Vehicle* v = NULL, CPerformanceTimer* pPerf = NULL)
KUDr@3900: 	{
KUDr@3900: 		Init(v, pPerf);
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	FORCEINLINE void Init(Vehicle* v, CPerformanceTimer* pPerf)
KUDr@3900: 	{
KUDr@3900: 		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;
KUDr@3900: 		m_is_tunnel = false;
KUDr@3900: 		m_tunnel_tiles_skipped = 0;
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;}
KUDr@3900: 	FORCEINLINE static bool IsRoadTT() {return TT() == TRANSPORT_ROAD;}
KUDr@3900: 	FORCEINLINE static bool Allow90degTurns() {return T90deg_turns_allowed_;}
KUDr@3900: 
KUDr@3900: 	/** main follower routine. Fills all members and return true on success.
KUDr@3900: 	    Otherwise returns false if track can't be followed. */
KUDr@3900: 	FORCEINLINE 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@3900: 		assert((GetTileTrackStatus(m_old_tile, TT()) & TrackdirToTrackdirBits(m_old_td)) != 0);
KUDr@3900: 		m_exitdir = TrackdirToExitdir(m_old_td);
KUDr@3900: 		if (EnteredRailDepot()) return true;
KUDr@3900: 		if (!CanExitOldTile()) return false;
KUDr@3900: 		FollowTileExit();
KUDr@3900: 		if (!QueryNewTileTrackStatus()) return false;
KUDr@3900: 		if (!CanEnterNewTile()) return false;
KUDr@3900: 		m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
KUDr@3900: 		if (!Allow90degTurns())
KUDr@3900: 			m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
KUDr@3900: 		return (m_new_td_bits != TRACKDIR_BIT_NONE);
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: protected:
KUDr@3900: 	/** Follow the m_exitdir from m_old_tile and fill m_new_tile and m_tunnel_tiles_skipped */
KUDr@3900: 	FORCEINLINE void FollowTileExit()
KUDr@3900: 	{
KUDr@3900: 		// extra handling for tunnels in our direction
KUDr@3900: 		if (IsTunnelTile(m_old_tile)) {
KUDr@3900: 			DiagDirection tunnel_enterdir = GetTunnelDirection(m_old_tile);
KUDr@3900: 			if (tunnel_enterdir == m_exitdir) {
KUDr@3900: 				// we are entering the tunnel
KUDr@3900: 				FindLengthOfTunnelResult flotr = FindLengthOfTunnel(m_old_tile, m_exitdir);
KUDr@3900: 				m_new_tile = flotr.tile;
KUDr@3900: 				m_is_tunnel = true;
KUDr@3900: 				m_tunnel_tiles_skipped = flotr.length - 1;
KUDr@3900: 				return;
KUDr@3900: 			}
KUDr@3900: 			assert(ReverseDiagDir(tunnel_enterdir) == m_exitdir);
KUDr@3900: 		}
KUDr@3900: 		// not a tunnel
KUDr@3900: 		m_is_tunnel = false;
KUDr@3900: 		m_tunnel_tiles_skipped = 0;
KUDr@3900: 		// normal tile
KUDr@3900: 		TileIndexDiff diff = TileOffsByDir(m_exitdir);
KUDr@3900: 		m_new_tile = TILE_ADD(m_old_tile, diff);
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 {
KUDr@3900: 			uint32 ts = GetTileTrackStatus(m_new_tile, TT());
KUDr@3900: 			m_new_td_bits = (TrackdirBits)(ts & TRACKDIR_BIT_MASK);
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: 	{
KUDr@3900: 		// road stop can be left at one direction only
KUDr@3900: 		if (IsRoadTT() && IsRoadStopTile(m_old_tile)) {
KUDr@3900: 			DiagDirection exitdir = GetRoadStopDir(m_old_tile);
KUDr@3900: 			if (exitdir != m_exitdir)
KUDr@3900: 				return false;
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// road depots can be also left in one direction only
KUDr@3900: 		if (IsRoadTT() && IsTileDepotType(m_old_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRoadDepotDirection(m_old_tile);
KUDr@3900: 			if (exitdir != m_exitdir)
KUDr@3900: 				return false;
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: 	{
KUDr@3900: 		if (IsRoadTT() && IsRoadStopTile(m_new_tile)) {
KUDr@3900: 			// road stop can be entered from one direction only
KUDr@3900: 			DiagDirection exitdir = GetRoadStopDir(m_new_tile);
KUDr@3900: 			if (ReverseDiagDir(exitdir) != m_exitdir)
KUDr@3900: 				return false;
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// road and rail depots can also be entered from one direction only
KUDr@3900: 		if (IsRoadTT() && IsTileDepotType(m_new_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRoadDepotDirection(m_new_tile);
KUDr@3900: 			if (ReverseDiagDir(exitdir) != m_exitdir)
KUDr@3900: 				return false;
KUDr@3900: 		}
KUDr@3900: 		if (IsRailTT() && IsTileDepotType(m_new_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRailDepotDirection(m_new_tile);
KUDr@3900: 			if (ReverseDiagDir(exitdir) != m_exitdir)
KUDr@3900: 				return false;
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@3900: 			if (IsBridgeTile(m_new_tile)) {
KUDr@3900: 				if (IsBridgeMiddle(m_new_tile)) {
KUDr@3900: 						// bridge middle has no owner - tile is owned by the owner of the under-bridge track
KUDr@3900: 					if (GetBridgeAxis(m_new_tile) != DiagDirToAxis(m_exitdir)) {
KUDr@3900: 						// so it must be under bridge track (and wrong owner)
KUDr@3900: 						return false;
KUDr@3900: 					}
KUDr@3900: 					// in the middle of the bridge - when we came here, it should be ok
KUDr@3900: 				} else {
KUDr@3900: 					// different owner, on the bridge ramp
KUDr@3900: 					return false;
KUDr@3900: 				}
KUDr@3900: 			} else {
KUDr@3900: 				// different owner, not a bridge
KUDr@3900: 				return false;
KUDr@3900: 			}
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// rail transport is possible only on compatible rail types
KUDr@3900: 		if (IsRailTT()) {
KUDr@3900: 			RailType rail_type = GetTileRailType(m_new_tile, DiagdirToDiagTrackdir(m_exitdir));
KUDr@3900: 			if (((1 << rail_type) & m_veh->u.rail.compatible_railtypes) == 0) {
KUDr@3900: 				// incompatible rail type
KUDr@3900: 				return false;
KUDr@3900: 			}
KUDr@3900: 		}
KUDr@3900: 
KUDr@3900: 		// tunnel tiles can be entered only from proper direction
KUDr@3900: 		if (!IsWaterTT() && !m_is_tunnel && IsTunnelTile(m_new_tile)) {
KUDr@3900: 			DiagDirection tunnel_enterdir = GetTunnelDirection(m_new_tile);
KUDr@3900: 			if (tunnel_enterdir != m_exitdir)
KUDr@3900: 				return false;
KUDr@3900: 		}
KUDr@3900: 		return true;
KUDr@3900: 	}
KUDr@3900: 
KUDr@3900: 	FORCEINLINE bool EnteredRailDepot()
KUDr@3900: 	{
KUDr@3900: 		// rail depots cause reversing
KUDr@3900: 		if (IsRailTT() && IsTileDepotType(m_old_tile, TT())) {
KUDr@3900: 			DiagDirection exitdir = GetRailDepotDirection(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@3900: 				m_tunnel_tiles_skipped = 0;
KUDr@3900: 				m_is_tunnel = false;
KUDr@3900: 				return true;
KUDr@3900: 			}
KUDr@3900: 		}
KUDr@3900: 		return false;
KUDr@3900: 	}
KUDr@3900: public:
KUDr@3900: 	/** Helper for pathfinders - get min/max speed on the m_old_tile/m_old_td */
KUDr@3900: 	int GetSpeedLimit(int *pmin_speed = NULL)
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
KUDr@3900: 		if (IsBridgeTile(m_old_tile) && !IsWaterTT() && IsDiagonalTrackdir(m_old_td)) {
KUDr@3900: 			bool is_on_bridge = true;
KUDr@3900: 			if (IsBridgeMiddle(m_old_tile)) {
KUDr@3900: 				// get track axis
KUDr@3900: 				Axis track_axis = DiagDirToAxis(TrackdirToExitdir(m_old_td));
KUDr@3900: 				// get under-bridge axis
KUDr@3900: 				Axis bridge_axis =  GetBridgeAxis(m_old_tile);
KUDr@3900: 				if (track_axis != bridge_axis) is_on_bridge = false;
KUDr@3900: 			}
KUDr@3900: 			if (is_on_bridge) {
KUDr@3900: 				int spd = _bridge[GetBridgeType(m_old_tile)].speed;
KUDr@3900: 				if (IsRoadTT()) spd *= 2;
KUDr@3900: 				if (max_speed > spd) max_speed = spd;
KUDr@3900: 			}
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 */