/* $Id$ */ /** @file follow_track.hpp Template function for track followers */ #ifndef FOLLOW_TRACK_HPP #define FOLLOW_TRACK_HPP #include "yapf.hpp" /** Track follower helper template class (can serve pathfinders and vehicle * controllers). See 6 different typedefs below for 3 different transport * types w/ of w/o 90-deg turns allowed */ template <TransportType Ttr_type_, bool T90deg_turns_allowed_ = true> struct CFollowTrackT { enum ErrorCode { EC_NONE, EC_OWNER, EC_RAIL_TYPE, EC_90DEG, EC_NO_WAY, }; const Vehicle* m_veh; ///< moving 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; FORCEINLINE CFollowTrackT(const Vehicle* v = NULL, CPerformanceTimer* pPerf = NULL) { Init(v, pPerf); } FORCEINLINE void Init(const Vehicle* v, CPerformanceTimer* pPerf) { assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN)); m_veh = v; 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; } 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(m_veh->u.road.compatible_roadtypes, ROADTYPE_TRAM);} FORCEINLINE static bool IsRoadTT() {return TT() == TRANSPORT_ROAD;} FORCEINLINE static bool Allow90degTurns() {return T90deg_turns_allowed_;} /** Tests if a tile is a road tile with a single tramtrack (tram can reverse) */ FORCEINLINE DiagDirection GetSingleTramBit(TileIndex tile) { if (IsTram() && 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. */ FORCEINLINE 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(), m_veh->u.road.compatible_roadtypes)) & TrackdirToTrackdirBits(m_old_td)) != 0) || (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; } 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() && IsRailwayStationTile(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() && GetTileType(m_new_tile) == MP_RAILWAY && 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(), m_veh->u.road.compatible_roadtypes)); if (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 */ 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() && IsTileDepotType(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 */ 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() && IsTileDepotType(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 player's depots if (GetTileOwner(m_new_tile) != m_veh->owner) { m_err = EC_OWNER; return false; } } if (IsRailTT() && IsTileDepotType(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_veh->u.rail.compatible_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 (!IsWaterTT() && 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 = GetStationByTile(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() && IsTileDepotType(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 (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, true > CFollowTrackWater; typedef CFollowTrackT<TRANSPORT_ROAD , true > CFollowTrackRoad; typedef CFollowTrackT<TRANSPORT_RAIL , true > CFollowTrackRail; typedef CFollowTrackT<TRANSPORT_WATER, false> CFollowTrackWaterNo90; typedef CFollowTrackT<TRANSPORT_ROAD , false> CFollowTrackRoadNo90; typedef CFollowTrackT<TRANSPORT_RAIL , false> CFollowTrackRailNo90; #endif /* FOLLOW_TRACK_HPP */