/* * 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 signal.cpp functions related to rail signals updating */ #include "stdafx.h" #include "debug.h" #include "station_map.h" #include "tunnelbridge_map.h" #include "vehicle_func.h" #include "viewport_func.h" #include "train.h" #include "company_base.h" #include "safeguards.h" /** these are the maximums used for updating signal blocks */ static const uint SIG_TBU_SIZE = 64; ///< number of signals entering to block static const uint SIG_TBD_SIZE = 256; ///< number of intersections - open nodes in current block static const uint SIG_GLOB_SIZE = 128; ///< number of open blocks (block can be opened more times until detected) static const uint SIG_GLOB_UPDATE = 64; ///< how many items need to be in _globset to force update assert_compile(SIG_GLOB_UPDATE <= SIG_GLOB_SIZE); /** incidating trackbits with given enterdir */ static const TrackBits _enterdir_to_trackbits[DIAGDIR_END] = { TRACK_BIT_3WAY_NE, TRACK_BIT_3WAY_SE, TRACK_BIT_3WAY_SW, TRACK_BIT_3WAY_NW }; /** incidating trackdirbits with given enterdir */ static const TrackdirBits _enterdir_to_trackdirbits[DIAGDIR_END] = { TRACKDIR_BIT_X_SW | TRACKDIR_BIT_UPPER_W | TRACKDIR_BIT_RIGHT_S, TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_LOWER_W | TRACKDIR_BIT_RIGHT_N, TRACKDIR_BIT_X_NE | TRACKDIR_BIT_LOWER_E | TRACKDIR_BIT_LEFT_N, TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E | TRACKDIR_BIT_LEFT_S }; /** * Set containing 'items' items of 'tile and Tdir' * No tree structure is used because it would cause * slowdowns in most usual cases */ template <typename Tdir, uint items> struct SmallSet { private: uint n; // actual number of units bool overflowed; // did we try to overflow the set? const char *name; // name, used for debugging purposes... /** Element of set */ struct SSdata { TileIndex tile; Tdir dir; } data[items]; public: /** Constructor - just set default values and 'name' */ SmallSet(const char *name) : n(0), overflowed(false), name(name) { } /** Reset variables to default values */ void Reset() { this->n = 0; this->overflowed = false; } /** * Returns value of 'overflowed' * @return did we try to overflow the set? */ bool Overflowed() { return this->overflowed; } /** * Checks for empty set * @return is the set empty? */ bool IsEmpty() { return this->n == 0; } /** * Checks for full set * @return is the set full? */ bool IsFull() { return this->n == lengthof(data); } /** * Reads the number of items * @return current number of items */ uint Items() { return this->n; } /** * Tries to remove first instance of given tile and dir * @param tile tile * @param dir and dir to remove * @return element was found and removed */ bool Remove(TileIndex tile, Tdir dir) { for (uint i = 0; i < this->n; i++) { if (this->data[i].tile == tile && this->data[i].dir == dir) { this->data[i] = this->data[--this->n]; return true; } } return false; } /** * Tries to find given tile and dir in the set * @param tile tile * @param dir and dir to find * @return true iff the tile & dir element was found */ bool IsIn(TileIndex tile, Tdir dir) { for (uint i = 0; i < this->n; i++) { if (this->data[i].tile == tile && this->data[i].dir == dir) return true; } return false; } /** * Adds tile & dir into the set, checks for full set * Sets the 'overflowed' flag if the set was full * @param tile tile * @param dir and dir to add * @return true iff the item could be added (set wasn't full) */ bool Add(TileIndex tile, Tdir dir) { if (this->IsFull()) { overflowed = true; DEBUG(misc, 0, "SignalSegment too complex. Set %s is full (maximum %d)", name, items); return false; // set is full } this->data[this->n].tile = tile; this->data[this->n].dir = dir; this->n++; return true; } /** * Reads the last added element into the set * @param tile pointer where tile is written to * @param dir pointer where dir is written to * @return false iff the set was empty */ bool Get(TileIndex *tile, Tdir *dir) { if (this->n == 0) return false; this->n--; *tile = this->data[this->n].tile; *dir = this->data[this->n].dir; return true; } }; static SmallSet<Trackdir, SIG_TBU_SIZE> _tbuset("_tbuset"); ///< set of signals that will be updated static SmallSet<DiagDirection, SIG_TBD_SIZE> _tbdset("_tbdset"); ///< set of open nodes in current signal block static SmallSet<DiagDirection, SIG_GLOB_SIZE> _globset("_globset"); ///< set of places to be updated in following runs /** Check whether there is a train on rail, not in a depot */ static Vehicle *TrainOnTileEnum(Vehicle *v, void *) { if (v->type != VEH_TRAIN || Train::From(v)->track == TRACK_BIT_DEPOT) return nullptr; return v; } /** * Perform some operations before adding data into Todo set * The new and reverse direction is removed from _globset, because we are sure * it doesn't need to be checked again * Also, remove reverse direction from _tbdset * This is the 'core' part so the graph searching won't enter any tile twice * * @param t1 tile we are entering * @param d1 direction (tile side) we are entering * @param t2 tile we are leaving * @param d2 direction (tile side) we are leaving * @return false iff reverse direction was in Todo set */ static inline bool CheckAddToTodoSet(TileIndex t1, DiagDirection d1, TileIndex t2, DiagDirection d2) { _globset.Remove(t1, d1); // it can be in Global but not in Todo _globset.Remove(t2, d2); // remove in all cases assert(!_tbdset.IsIn(t1, d1)); // it really shouldn't be there already if (_tbdset.Remove(t2, d2)) return false; return true; } /** * Perform some operations before adding data into Todo set * The new and reverse direction is removed from Global set, because we are sure * it doesn't need to be checked again * Also, remove reverse direction from Todo set * This is the 'core' part so the graph searching won't enter any tile twice * * @param t1 tile we are entering * @param d1 direction (tile side) we are entering * @param t2 tile we are leaving * @param d2 direction (tile side) we are leaving * @return false iff the Todo buffer would be overrun */ static inline bool MaybeAddToTodoSet(TileIndex t1, DiagDirection d1, TileIndex t2, DiagDirection d2) { if (!CheckAddToTodoSet(t1, d1, t2, d2)) return true; return _tbdset.Add(t1, d1); } /** Current signal block state flags */ enum SigFlags { SF_NONE = 0, SF_TRAIN = 1 << 0, ///< train found in segment SF_EXIT = 1 << 1, ///< exitsignal found SF_EXIT2 = 1 << 2, ///< two or more exits found SF_GREEN = 1 << 3, ///< green exitsignal found SF_GREEN2 = 1 << 4, ///< two or more green exits found SF_FULL = 1 << 5, ///< some of buffers was full, do not continue SF_PBS = 1 << 6, ///< pbs signal found }; DECLARE_ENUM_AS_BIT_SET(SigFlags) /** * Search signal block * * @param owner owner whose signals we are updating * @return SigFlags */ static SigFlags ExploreSegment(Owner owner) { SigFlags flags = SF_NONE; TileIndex tile; DiagDirection enterdir; while (_tbdset.Get(&tile, &enterdir)) { TileIndex oldtile = tile; // tile we are leaving DiagDirection exitdir = enterdir == INVALID_DIAGDIR ? INVALID_DIAGDIR : ReverseDiagDir(enterdir); // expected new exit direction (for straight line) switch (GetTileType(tile)) { case MP_RAILWAY: { if (GetTileOwner(tile) != owner) continue; // do not propagate signals on others' tiles (remove for tracksharing) if (IsRailDepot(tile)) { if (enterdir == INVALID_DIAGDIR) { // from 'inside' - train just entered or left the depot if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; exitdir = GetRailDepotDirection(tile); tile += TileOffsByDiagDir(exitdir); enterdir = ReverseDiagDir(exitdir); break; } else if (enterdir == GetRailDepotDirection(tile)) { // entered a depot if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; continue; } else { continue; } } assert(IsValidDiagDirection(enterdir)); TrackBits tracks = GetTrackBits(tile); // trackbits of tile TrackBits tracks_masked = (TrackBits)(tracks & _enterdir_to_trackbits[enterdir]); // only incidating trackbits if (tracks == TRACK_BIT_HORZ || tracks == TRACK_BIT_VERT) { // there is exactly one incidating track, no need to check tracks = tracks_masked; /* If no train detected yet, and there is not no train -> there is a train -> set the flag */ if (!(flags & SF_TRAIN) && EnsureNoTrainOnTrackBits(tile, tracks).Failed()) flags |= SF_TRAIN; } else { if (tracks_masked == TRACK_BIT_NONE) continue; // no incidating track if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; } if (HasSignals(tile)) { // there is exactly one track - not zero, because there is exit from this tile Track track = TrackBitsToTrack(tracks_masked); // mask TRACK_BIT_X and Y too if (HasSignalOnTrack(tile, track)) { // now check whole track, not trackdir SignalType sig = GetSignalType(tile, track); Trackdir trackdir = (Trackdir)FindFirstBit((tracks * 0x101) & _enterdir_to_trackdirbits[enterdir]); Trackdir reversedir = ReverseTrackdir(trackdir); /* add (tile, reversetrackdir) to 'to-be-updated' set when there is * ANY conventional signal in REVERSE direction * (if it is a presignal EXIT and it changes, it will be added to 'to-be-done' set later) */ if (HasSignalOnTrackdir(tile, reversedir)) { if (IsPbsSignal(sig)) { flags |= SF_PBS; } else if (!_tbuset.Add(tile, reversedir)) { return flags | SF_FULL; } } if (HasSignalOnTrackdir(tile, trackdir) && !IsOnewaySignal(tile, track)) flags |= SF_PBS; /* if it is a presignal EXIT in OUR direction and we haven't found 2 green exits yes, do special check */ if (!(flags & SF_GREEN2) && IsPresignalExit(tile, track) && HasSignalOnTrackdir(tile, trackdir)) { // found presignal exit if (flags & SF_EXIT) flags |= SF_EXIT2; // found two (or more) exits flags |= SF_EXIT; // found at least one exit - allow for compiler optimizations if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_GREEN) { // found green presignal exit if (flags & SF_GREEN) flags |= SF_GREEN2; flags |= SF_GREEN; } } continue; } } for (DiagDirection dir = DIAGDIR_BEGIN; dir < DIAGDIR_END; dir++) { // test all possible exit directions if (dir != enterdir && (tracks & _enterdir_to_trackbits[dir])) { // any track incidating? TileIndex newtile = tile + TileOffsByDiagDir(dir); // new tile to check DiagDirection newdir = ReverseDiagDir(dir); // direction we are entering from if (!MaybeAddToTodoSet(newtile, newdir, tile, dir)) return flags | SF_FULL; } } continue; // continue the while() loop } case MP_STATION: if (!HasStationRail(tile)) continue; if (GetTileOwner(tile) != owner) continue; if (DiagDirToAxis(enterdir) != GetRailStationAxis(tile)) continue; // different axis if (IsStationTileBlocked(tile)) continue; // 'eye-candy' station tile if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; tile += TileOffsByDiagDir(exitdir); break; case MP_ROAD: if (!IsLevelCrossing(tile)) continue; if (GetTileOwner(tile) != owner) continue; if (DiagDirToAxis(enterdir) == GetCrossingRoadAxis(tile)) continue; // different axis if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; tile += TileOffsByDiagDir(exitdir); break; case MP_TUNNELBRIDGE: { if (GetTileOwner(tile) != owner) continue; if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue; DiagDirection dir = GetTunnelBridgeDirection(tile); if (enterdir == INVALID_DIAGDIR) { // incoming from the wormhole if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; enterdir = dir; exitdir = ReverseDiagDir(dir); tile += TileOffsByDiagDir(exitdir); // just skip to next tile } else { // NOT incoming from the wormhole! if (ReverseDiagDir(enterdir) != dir) continue; if (!(flags & SF_TRAIN) && HasVehicleOnPos(tile, nullptr, &TrainOnTileEnum)) flags |= SF_TRAIN; tile = GetOtherTunnelBridgeEnd(tile); // just skip to exit tile enterdir = INVALID_DIAGDIR; exitdir = INVALID_DIAGDIR; } } break; default: continue; // continue the while() loop } if (!MaybeAddToTodoSet(tile, enterdir, oldtile, exitdir)) return flags | SF_FULL; } return flags; } /** * Update signals around segment in _tbuset * * @param flags info about segment */ static void UpdateSignalsAroundSegment(SigFlags flags) { TileIndex tile; Trackdir trackdir; while (_tbuset.Get(&tile, &trackdir)) { assert(HasSignalOnTrackdir(tile, trackdir)); SignalType sig = GetSignalType(tile, TrackdirToTrack(trackdir)); SignalState newstate = SIGNAL_STATE_GREEN; /* determine whether the new state is red */ if (flags & SF_TRAIN) { /* train in the segment */ newstate = SIGNAL_STATE_RED; } else { /* is it a bidir combo? - then do not count its other signal direction as exit */ if (sig == SIGTYPE_COMBO && HasSignalOnTrackdir(tile, ReverseTrackdir(trackdir))) { /* at least one more exit */ if ((flags & SF_EXIT2) && /* no green exit */ (!(flags & SF_GREEN) || /* only one green exit, and it is this one - so all other exits are red */ (!(flags & SF_GREEN2) && GetSignalStateByTrackdir(tile, ReverseTrackdir(trackdir)) == SIGNAL_STATE_GREEN))) { newstate = SIGNAL_STATE_RED; } } else { // entry, at least one exit, no green exit if (IsPresignalEntry(tile, TrackdirToTrack(trackdir)) && (flags & SF_EXIT) && !(flags & SF_GREEN)) newstate = SIGNAL_STATE_RED; } } /* only when the state changes */ if (newstate != GetSignalStateByTrackdir(tile, trackdir)) { if (IsPresignalExit(tile, TrackdirToTrack(trackdir))) { /* for pre-signal exits, add block to the global set */ DiagDirection exitdir = TrackdirToExitdir(ReverseTrackdir(trackdir)); _globset.Add(tile, exitdir); // do not check for full global set, first update all signals } SetSignalStateByTrackdir(tile, trackdir, newstate); MarkTileDirtyByTile(tile); } } } /** Reset all sets after one set overflowed */ static inline void ResetSets() { _tbuset.Reset(); _tbdset.Reset(); _globset.Reset(); } /** * Updates blocks in _globset buffer * * @param owner company whose signals we are updating * @return state of the first block from _globset * @pre Company::IsValidID(owner) */ static SigSegState UpdateSignalsInBuffer(Owner owner) { assert(Company::IsValidID(owner)); bool first = true; // first block? SigSegState state = SIGSEG_FREE; // value to return TileIndex tile; DiagDirection dir; while (_globset.Get(&tile, &dir)) { assert(_tbuset.IsEmpty()); assert(_tbdset.IsEmpty()); /* After updating signal, data stored are always MP_RAILWAY with signals. * Other situations happen when data are from outside functions - * modification of railbits (including both rail building and removal), * train entering/leaving block, train leaving depot... */ switch (GetTileType(tile)) { case MP_TUNNELBRIDGE: /* 'optimization assert' - do not try to update signals when it is not needed */ assert(GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL); assert(dir == INVALID_DIAGDIR || dir == ReverseDiagDir(GetTunnelBridgeDirection(tile))); _tbdset.Add(tile, INVALID_DIAGDIR); // we can safely start from wormhole centre _tbdset.Add(GetOtherTunnelBridgeEnd(tile), INVALID_DIAGDIR); break; case MP_RAILWAY: if (IsRailDepot(tile)) { /* 'optimization assert' do not try to update signals in other cases */ assert(dir == INVALID_DIAGDIR || dir == GetRailDepotDirection(tile)); _tbdset.Add(tile, INVALID_DIAGDIR); // start from depot inside break; } FALLTHROUGH; case MP_STATION: case MP_ROAD: if ((TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0)) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) { /* only add to set when there is some 'interesting' track */ _tbdset.Add(tile, dir); _tbdset.Add(tile + TileOffsByDiagDir(dir), ReverseDiagDir(dir)); break; } FALLTHROUGH; default: /* jump to next tile */ tile = tile + TileOffsByDiagDir(dir); dir = ReverseDiagDir(dir); if ((TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0)) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) { _tbdset.Add(tile, dir); break; } /* happens when removing a rail that wasn't connected at one or both sides */ continue; // continue the while() loop } assert(!_tbdset.Overflowed()); // it really shouldn't overflow by these one or two items assert(!_tbdset.IsEmpty()); // it wouldn't hurt anyone, but shouldn't happen too SigFlags flags = ExploreSegment(owner); if (first) { first = false; /* SIGSEG_FREE is set by default */ if (flags & SF_PBS) { state = SIGSEG_PBS; } else if ((flags & SF_TRAIN) || ((flags & SF_EXIT) && !(flags & SF_GREEN)) || (flags & SF_FULL)) { state = SIGSEG_FULL; } } /* do not do anything when some buffer was full */ if (flags & SF_FULL) { ResetSets(); // free all sets break; } UpdateSignalsAroundSegment(flags); } return state; } static Owner _last_owner = INVALID_OWNER; ///< last owner whose track was put into _globset /** * Update signals in buffer * Called from 'outside' */ void UpdateSignalsInBuffer() { if (!_globset.IsEmpty()) { UpdateSignalsInBuffer(_last_owner); _last_owner = INVALID_OWNER; // invalidate } } /** * Add track to signal update buffer * * @param tile tile where we start * @param track track at which ends we will update signals * @param owner owner whose signals we will update */ void AddTrackToSignalBuffer(TileIndex tile, Track track, Owner owner) { static const DiagDirection _search_dir_1[] = { DIAGDIR_NE, DIAGDIR_SE, DIAGDIR_NE, DIAGDIR_SE, DIAGDIR_SW, DIAGDIR_SE }; static const DiagDirection _search_dir_2[] = { DIAGDIR_SW, DIAGDIR_NW, DIAGDIR_NW, DIAGDIR_SW, DIAGDIR_NW, DIAGDIR_NE }; /* do not allow signal updates for two companies in one run */ assert(_globset.IsEmpty() || owner == _last_owner); _last_owner = owner; _globset.Add(tile, _search_dir_1[track]); _globset.Add(tile, _search_dir_2[track]); if (_globset.Items() >= SIG_GLOB_UPDATE) { /* too many items, force update */ UpdateSignalsInBuffer(_last_owner); _last_owner = INVALID_OWNER; } } /** * Add side of tile to signal update buffer * * @param tile tile where we start * @param side side of tile * @param owner owner whose signals we will update */ void AddSideToSignalBuffer(TileIndex tile, DiagDirection side, Owner owner) { /* do not allow signal updates for two companies in one run */ assert(_globset.IsEmpty() || owner == _last_owner); _last_owner = owner; _globset.Add(tile, side); if (_globset.Items() >= SIG_GLOB_UPDATE) { /* too many items, force update */ UpdateSignalsInBuffer(_last_owner); _last_owner = INVALID_OWNER; } } /** * Update signals, starting at one side of a tile * Will check tile next to this at opposite side too * * @see UpdateSignalsInBuffer() * @param tile tile where we start * @param side side of tile * @param owner owner whose signals we will update * @return the state of the signal segment */ SigSegState UpdateSignalsOnSegment(TileIndex tile, DiagDirection side, Owner owner) { assert(_globset.IsEmpty()); _globset.Add(tile, side); return UpdateSignalsInBuffer(owner); } /** * Update signals at segments that are at both ends of * given (existent or non-existent) track * * @see UpdateSignalsInBuffer() * @param tile tile where we start * @param track track at which ends we will update signals * @param owner owner whose signals we will update */ void SetSignalsOnBothDir(TileIndex tile, Track track, Owner owner) { assert(_globset.IsEmpty()); AddTrackToSignalBuffer(tile, track, owner); UpdateSignalsInBuffer(owner); }