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Diffstat (limited to 'src/signal.cpp')
| -rw-r--r-- | src/signal.cpp | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/src/signal.cpp b/src/signal.cpp new file mode 100644 index 000000000..79997461c --- /dev/null +++ b/src/signal.cpp @@ -0,0 +1,582 @@ +/* $Id$ */ + +/** @file signal.cpp functions related to rail signals updating */ + +#include "stdafx.h" +#include "openttd.h" +#include "debug.h" +#include "tile_cmd.h" +#include "rail_map.h" +#include "road_map.h" +#include "station_map.h" +#include "tunnelbridge_map.h" +#include "vehicle_func.h" +#include "train.h" +#include "newgrf_station.h" +#include "functions.h" +#include "track_type.h" +#include "track_func.h" +#include "signal_func.h" +#include "player.h" + + +/** these are the maximums used for updating signal blocks */ +enum { + SIG_TBU_SIZE = 64, ///< number of signals entering to block + SIG_TBD_SIZE = 256, ///< number of intersections - open nodes in current block + SIG_GLOB_SIZE = 64, ///< number of open blocks (block can be opened more times until detected) +}; + +/** incidating trackbits with given enterdir */ +static const TrackBitsByte _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 TrackdirBitsShort _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 oveflow 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 'oveflowed' + * @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); + } + + /** + * 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 elemnt 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 void *TrainOnTileEnum(Vehicle *v, void *) +{ + if (v->type != VEH_TRAIN || v->u.rail.track == TRACK_BIT_DEPOT) return NULL; + + 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 seaching 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 seaching 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 +}; + +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; + + while (!_tbdset.IsEmpty()) { + TileIndex tile; + DiagDirection enterdir; + + _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) && VehicleFromPos(tile, NULL, &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) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN; + continue; + } else { + continue; + } + } + + if (GetRailTileType(tile) == RAIL_TILE_WAYPOINT) { + if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN; + tile += TileOffsByDiagDir(exitdir); + /* enterdir and exitdir stay the same */ + break; + } + + 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 (!(flags & SF_TRAIN) && VehicleFromPos(tile, &tracks, &EnsureNoTrainOnTrackProc)) flags |= SF_TRAIN; + } else { + if (tracks_masked == TRACK_BIT_NONE) continue; // no incidating track + if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &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 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 (!_tbuset.Add(tile, reversedir)) return flags | SF_FULL; + } + /* 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) && (sig & SIGTYPE_EXIT) && 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 (!IsRailwayStation(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) && VehicleFromPos(tile, NULL, &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) && VehicleFromPos(tile, NULL, &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) && VehicleFromPos(tile, NULL, &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) && VehicleFromPos(tile, NULL, &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) +{ + while (!_tbuset.IsEmpty()) { + TileIndex tile; + Trackdir trackdir; + _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 (sig & SIGTYPE_ENTRY && (flags & SF_EXIT && !(flags & SF_GREEN))) newstate = SIGNAL_STATE_RED; + } + } + + /* only when the state changes */ + if (newstate != GetSignalStateByTrackdir(tile, trackdir)) { + if (sig & SIGTYPE_EXIT) { + /* 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 + * + * @return false iff presignal entry would be green (needed for trains leaving depot) + */ +static bool UpdateSignalsInBuffer() +{ + bool first = true; // first block? + bool state = false; // value to return + + Owner owner = OWNER_NONE; // owner whose signals we are updating + + while (!_globset.IsEmpty()) { + assert(_tbuset.IsEmpty()); + assert(_tbdset.IsEmpty()); + + TileIndex tile; + DiagDirection dir; + + _globset.Get(&tile, &dir); + + /* 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))); + if (first) owner = GetTileOwner(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)); + if (first) owner = GetTileOwner(tile); + _tbdset.Add(tile, INVALID_DIAGDIR); // start from depot inside + break; + } + /* FALLTHROUGH */ + case MP_STATION: + case MP_ROAD: + if ((TrackBits)(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) { + /* only add to set when there is some 'interesting' track */ + if (first) owner = GetTileOwner(tile); + _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 ((TrackBits)(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) { + if (first) owner = GetTileOwner(tile); + _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(IsValidPlayer(owner)); + 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; + state = (flags & SF_TRAIN) || (flags & SF_EXIT && !(flags & SF_GREEN)) || (flags & SF_FULL); // true iff train CAN'T leave the depot + } + + /* do not do anything when some buffer was full */ + if (flags & SF_FULL) break; + + UpdateSignalsAroundSegment(flags); + } + + return state; +} + + +/** + * 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 + * @return false iff train can leave depot + */ +bool UpdateSignalsOnSegment(TileIndex tile, DiagDirection side) +{ + assert(_globset.IsEmpty()); + _globset.Add(tile, side); + + return UpdateSignalsInBuffer(); +} + + +/** + * 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 + */ +void SetSignalsOnBothDir(TileIndex tile, Track track) +{ + 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 + }; + + assert(_globset.IsEmpty()); + + _globset.Add(tile, _search_dir_1[track]); + _globset.Add(tile, _search_dir_2[track]); + UpdateSignalsInBuffer(); +} |