1

/* $Id$ */

     2

     3

/** @file signal.cpp functions related to rail signals updating */

     4

     5

#include "stdafx.h"

     6

#include "openttd.h"

     7

#include "debug.h"

     8

#include "tile_cmd.h"

     9

#include "rail_map.h"

    10

#include "road_map.h"

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#include "station_map.h"

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#include "tunnelbridge_map.h"

    13

#include "vehicle_func.h"

    14

#include "train.h"

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#include "newgrf_station.h"

    16

#include "functions.h"

    17

#include "track_type.h"

    18

#include "track_func.h"

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#include "signal_func.h"

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#include "player_func.h"

    21

    22

    23

/** these are the maximums used for updating signal blocks */

    24

enum {

    29

};

    30

    33

/** incidating trackbits with given enterdir */

    34

static const TrackBitsByte _enterdir_to_trackbits[DIAGDIR_END] = {

    35

	{TRACK_BIT_3WAY_NE},

    36

	{TRACK_BIT_3WAY_SE},

    37

	{TRACK_BIT_3WAY_SW},

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	{TRACK_BIT_3WAY_NW}

    39

};

    40

    41

/** incidating trackdirbits with given enterdir */

    42

static const TrackdirBitsShort _enterdir_to_trackdirbits[DIAGDIR_END] = {

    43

	{TRACKDIR_BIT_X_SW | TRACKDIR_BIT_UPPER_W | TRACKDIR_BIT_RIGHT_S},

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	{TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_LOWER_W | TRACKDIR_BIT_RIGHT_N},

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	{TRACKDIR_BIT_X_NE | TRACKDIR_BIT_LOWER_E | TRACKDIR_BIT_LEFT_N},

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	{TRACKDIR_BIT_Y_SE | TRACKDIR_BIT_UPPER_E | TRACKDIR_BIT_LEFT_S}

    47

};

    48

    49

/**

    50

 * Set containing 'items' items of 'tile and Tdir'

    51

 * No tree structure is used because it would cause

    52

 * slowdowns in most usual cases

    53

 */

    54

template <typename Tdir, uint items>

    55

struct SmallSet {

    56

private:

    57

	uint n;           // actual number of units

    58

	bool overflowed;  // did we try to oveflow the set?

    59

	const char *name; // name, used for debugging purposes...

    60

    61

	/** Element of set */

    62

	struct SSdata {

    63

		TileIndex tile;

    64

		Tdir dir;

    65

	} data[items];

    66

    67

public:

    68

	/** Constructor - just set default values and 'name' */

    69

	SmallSet(const char *name) : n(0), overflowed(false), name(name) { }

    70

    71

	/** Reset variables to default values */

    72

	void Reset()

    73

	{

    74

		this->n = 0;

    75

		this->overflowed = false;

    76

	}

    77

    78

	/**

    79

	 * Returns value of 'oveflowed'

    80

	 * @return did we try to overflow the set?

    81

	 */

    82

	bool Overflowed()

    83

	{

    84

		return this->overflowed;

    85

	}

    86

    87

	/**

    88

	 * Checks for empty set

    89

	 * @return is the set empty?

    90

	 */

    91

	bool IsEmpty()

    92

	{

    93

		return this->n == 0;

    94

	}

    95

    96

	/**

    97

	 * Checks for full set

    98

	 * @return is the set full?

    99

	 */

   100

	bool IsFull()

   101

	{

   102

		return this->n == lengthof(data);

   103

	}

   104

   105

	/**

   116

	 * Tries to remove first instance of given tile and dir

   117

	 * @param tile tile

   118

	 * @param dir and dir to remove

   119

	 * @return element was found and removed

   120

	 */

   121

	bool Remove(TileIndex tile, Tdir dir)

   122

	{

   123

		for (uint i = 0; i < this->n; i++) {

   124

			if (this->data[i].tile == tile && this->data[i].dir == dir) {

   125

				this->data[i] = this->data[--this->n];

   126

				return true;

   127

			}

   128

		}

   129

   130

		return false;

   131

	}

   132

   133

	/**

   134

	 * Tries to find given tile and dir in the set

   135

	 * @param tile tile

   136

	 * @param dir and dir to find

   137

	 * @return true iff the tile & dir elemnt was found

   138

	 */

   139

	bool IsIn(TileIndex tile, Tdir dir)

   140

	{

   141

		for (uint i = 0; i < this->n; i++) {

   142

			if (this->data[i].tile == tile && this->data[i].dir == dir) return true;

   143

		}

   144

   145

		return false;

   146

	}

   147

   148

	/**

   149

	 * Adds tile & dir into the set, checks for full set

   150

	 * Sets the 'overflowed' flag if the set was full

   151

	 * @param tile tile

   152

	 * @param dir and dir to add

   153

	 * @return true iff the item could be added (set wasn't full)

   154

	 */

   155

	bool Add(TileIndex tile, Tdir dir)

   156

	{

   157

		if (this->IsFull()) {

   158

			overflowed = true;

   159

			DEBUG(misc, 0, "SignalSegment too complex. Set %s is full (maximum %d)", name, items);

   160

			return false; // set is full

   161

		}

   162

   163

		this->data[this->n].tile = tile;

   164

		this->data[this->n].dir = dir;

   165

		this->n++;

   166

   167

		return true;

   168

	}

   169

   170

	/**

   171

	 * Reads the last added element into the set

   172

	 * @param tile pointer where tile is written to

   173

	 * @param dir pointer where dir is written to

   174

	 * @return false iff the set was empty

   175

	 */

   176

	bool Get(TileIndex *tile, Tdir *dir)

   177

	{

   178

		if (this->n == 0) return false;

   179

   180

		this->n--;

   181

		*tile = this->data[this->n].tile;

   182

		*dir = this->data[this->n].dir;

   183

   184

		return true;

   185

	}

   186

};

   187

   188

static SmallSet<Trackdir, SIG_TBU_SIZE> _tbuset("_tbuset");         ///< set of signals that will be updated

   189

static SmallSet<DiagDirection, SIG_TBD_SIZE> _tbdset("_tbdset");    ///< set of open nodes in current signal block

   190

static SmallSet<DiagDirection, SIG_GLOB_SIZE> _globset("_globset"); ///< set of places to be updated in following runs

   191

   192

   193

/** Check whether there is a train on rail, not in a depot */

   194

static void *TrainOnTileEnum(Vehicle *v, void *)

   195

{

   196

	if (v->type != VEH_TRAIN || v->u.rail.track == TRACK_BIT_DEPOT) return NULL;

   197

   198

	return v;

   199

}

   200

   201

   202

/**

   203

 * Perform some operations before adding data into Todo set

   204

 * The new and reverse direction is removed from _globset, because we are sure

   205

 * it doesn't need to be checked again

   206

 * Also, remove reverse direction from _tbdset

   207

 * This is the 'core' part so the graph seaching won't enter any tile twice

   208

 *

   209

 * @param t1 tile we are entering

   210

 * @param d1 direction (tile side) we are entering

   211

 * @param t2 tile we are leaving

   212

 * @param d2 direction (tile side) we are leaving

   213

 * @return false iff reverse direction was in Todo set

   214

 */

   215

static inline bool CheckAddToTodoSet(TileIndex t1, DiagDirection d1, TileIndex t2, DiagDirection d2)

   216

{

   217

	_globset.Remove(t1, d1); // it can be in Global but not in Todo

   218

	_globset.Remove(t2, d2); // remove in all cases

   219

   220

	assert(!_tbdset.IsIn(t1, d1)); // it really shouldn't be there already

   221

   222

	if (_tbdset.Remove(t2, d2)) return false;

   223

   224

	return true;

   225

}

   226

   227

   228

/**

   229

 * Perform some operations before adding data into Todo set

   230

 * The new and reverse direction is removed from Global set, because we are sure

   231

 * it doesn't need to be checked again

   232

 * Also, remove reverse direction from Todo set

   233

 * This is the 'core' part so the graph seaching won't enter any tile twice

   234

 *

   235

 * @param t1 tile we are entering

   236

 * @param d1 direction (tile side) we are entering

   237

 * @param t2 tile we are leaving

   238

 * @param d2 direction (tile side) we are leaving

   239

 * @return false iff the Todo buffer would be overrun

   240

 */

   241

static inline bool MaybeAddToTodoSet(TileIndex t1, DiagDirection d1, TileIndex t2, DiagDirection d2)

   242

{

   243

	if (!CheckAddToTodoSet(t1, d1, t2, d2)) return true;

   244

   245

	return _tbdset.Add(t1, d1);

   246

}

   247

   248

   249

/** Current signal block state flags */

   250

enum SigFlags {

   251

	SF_NONE   = 0,

   252

	SF_TRAIN  = 1 << 0, ///< train found in segment

   253

	SF_EXIT   = 1 << 1, ///< exitsignal found

   254

	SF_EXIT2  = 1 << 2, ///< two or more exits found

   255

	SF_GREEN  = 1 << 3, ///< green exitsignal found

   256

	SF_GREEN2 = 1 << 4, ///< two or more green exits found

   257

	SF_FULL   = 1 << 5, ///< some of buffers was full, do not continue

   258

};

   259

   260

DECLARE_ENUM_AS_BIT_SET(SigFlags)

   261

   262

   263

/**

   264

 * Search signal block

   265

 *

   266

 * @param owner owner whose signals we are updating

   267

 * @return SigFlags

   268

 */

   269

static SigFlags ExploreSegment(Owner owner)

   270

{

   271

	SigFlags flags = SF_NONE;

   272

   273

	TileIndex tile;

   274

	DiagDirection enterdir;

   275

   276

	while (_tbdset.Get(&tile, &enterdir)) {

   277

		TileIndex oldtile = tile; // tile we are leaving

   278

		DiagDirection exitdir = enterdir == INVALID_DIAGDIR ? INVALID_DIAGDIR : ReverseDiagDir(enterdir); // expected new exit direction (for straight line)

   279

   280

		switch (GetTileType(tile)) {

   281

			case MP_RAILWAY: {

   282

				if (GetTileOwner(tile) != owner) continue; // do not propagate signals on others' tiles (remove for tracksharing)

   283

   284

				if (IsRailDepot(tile)) {

   285

					if (enterdir == INVALID_DIAGDIR) { // from 'inside' - train just entered or left the depot

   286

						if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   287

						exitdir = GetRailDepotDirection(tile);

   288

						tile += TileOffsByDiagDir(exitdir);

   289

						enterdir = ReverseDiagDir(exitdir);

   290

						break;

   291

					} else if (enterdir == GetRailDepotDirection(tile)) { // entered a depot

   292

						if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   293

						continue;

   294

					} else {

   295

						continue;

   296

					}

   297

				}

   298

   299

				if (GetRailTileType(tile) == RAIL_TILE_WAYPOINT) {

   300

					if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   301

					tile += TileOffsByDiagDir(exitdir);

   302

					/* enterdir and exitdir stay the same */

   303

					break;

   304

				}

   305

   306

				TrackBits tracks = GetTrackBits(tile); // trackbits of tile

   307

				TrackBits tracks_masked = (TrackBits)(tracks & _enterdir_to_trackbits[enterdir]); // only incidating trackbits

   308

   309

				if (tracks == TRACK_BIT_HORZ || tracks == TRACK_BIT_VERT) { // there is exactly one incidating track, no need to check

   310

					tracks = tracks_masked;

   311

					if (!(flags & SF_TRAIN) && VehicleFromPos(tile, &tracks, &EnsureNoTrainOnTrackProc)) flags |= SF_TRAIN;

   312

				} else {

   313

					if (tracks_masked == TRACK_BIT_NONE) continue; // no incidating track

   314

					if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   315

				}

   316

   317

				if (HasSignals(tile)) { // there is exactly one track - not zero, because there is exit from this tile

   318

					Track track = TrackBitsToTrack(tracks_masked); // mask TRACK_BIT_X and Y too

   319

					if (HasSignalOnTrack(tile, track)) { // now check whole track, not trackdir

   320

						SignalType sig = GetSignalType(tile, track);

   321

						Trackdir trackdir = (Trackdir)FindFirstBit((tracks * 0x101) & _enterdir_to_trackdirbits[enterdir]);

   322

						Trackdir reversedir = ReverseTrackdir(trackdir);

   323

						/* add (tile, reversetrackdir) to 'to-be-updated' set when there is

   324

						 * ANY signal in REVERSE direction

   325

						 * (if it is a presignal EXIT and it changes, it will be added to 'to-be-done' set later) */

   326

						if (HasSignalOnTrackdir(tile, reversedir)) {

   327

							if (!_tbuset.Add(tile, reversedir)) return flags | SF_FULL;

   328

						}

   329

						/* if it is a presignal EXIT in OUR direction and we haven't found 2 green exits yes, do special check */

   330

						if (!(flags & SF_GREEN2) && (sig & SIGTYPE_EXIT) && HasSignalOnTrackdir(tile, trackdir)) { // found presignal exit

   331

							if (flags & SF_EXIT) flags |= SF_EXIT2; // found two (or more) exits

   332

							flags |= SF_EXIT; // found at least one exit - allow for compiler optimizations

   333

							if (GetSignalStateByTrackdir(tile, trackdir) == SIGNAL_STATE_GREEN) { // found green presignal exit

   334

								if (flags & SF_GREEN) flags |= SF_GREEN2;

   335

								flags |= SF_GREEN;

   336

							}

   337

						}

   338

						continue;

   339

					}

   340

				}

   341

   342

				for (DiagDirection dir = DIAGDIR_BEGIN; dir < DIAGDIR_END; dir++) { // test all possible exit directions

   343

					if (dir != enterdir && tracks & _enterdir_to_trackbits[dir]) { // any track incidating?

   344

						TileIndex newtile = tile + TileOffsByDiagDir(dir);  // new tile to check

   345

						DiagDirection newdir = ReverseDiagDir(dir); // direction we are entering from

   346

						if (!MaybeAddToTodoSet(newtile, newdir, tile, dir)) return flags | SF_FULL;

   347

					}

   348

				}

   349

   350

				continue; // continue the while() loop

   351

				}

   352

   353

			case MP_STATION:

   354

				if (!IsRailwayStation(tile)) continue;

   355

				if (GetTileOwner(tile) != owner) continue;

   356

				if (DiagDirToAxis(enterdir) != GetRailStationAxis(tile)) continue; // different axis

   357

				if (IsStationTileBlocked(tile)) continue; // 'eye-candy' station tile

   358

   359

				if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   360

				tile += TileOffsByDiagDir(exitdir);

   361

				break;

   362

   363

			case MP_ROAD:

   364

				if (!IsLevelCrossing(tile)) continue;

   365

				if (GetTileOwner(tile) != owner) continue;

   366

				if (DiagDirToAxis(enterdir) == GetCrossingRoadAxis(tile)) continue; // different axis

   367

   368

				if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   369

				tile += TileOffsByDiagDir(exitdir);

   370

				break;

   371

   372

			case MP_TUNNELBRIDGE: {

   373

				if (GetTileOwner(tile) != owner) continue;

   374

				if (GetTunnelBridgeTransportType(tile) != TRANSPORT_RAIL) continue;

   375

				DiagDirection dir = GetTunnelBridgeDirection(tile);

   376

   377

				if (enterdir == INVALID_DIAGDIR) { // incoming from the wormhole

   378

					if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   379

					enterdir = dir;

   380

					exitdir = ReverseDiagDir(dir);

   381

					tile += TileOffsByDiagDir(exitdir); // just skip to next tile

   382

				} else { // NOT incoming from the wormhole!

   383

					if (ReverseDiagDir(enterdir) != dir) continue;

   384

					if (!(flags & SF_TRAIN) && VehicleFromPos(tile, NULL, &TrainOnTileEnum)) flags |= SF_TRAIN;

   385

					tile = GetOtherTunnelBridgeEnd(tile); // just skip to exit tile

   386

					enterdir = INVALID_DIAGDIR;

   387

					exitdir = INVALID_DIAGDIR;

   388

				}

   389

				}

   390

				break;

   391

   392

			default:

   393

				continue; // continue the while() loop

   394

		}

   395

   396

		if (!MaybeAddToTodoSet(tile, enterdir, oldtile, exitdir)) return flags | SF_FULL;

   397

	}

   398

   399

	return flags;

   400

}

   401

   402

   403

/**

   404

 * Update signals around segment in _tbuset

   405

 *

   406

 * @param flags info about segment

   407

 */

   408

static void UpdateSignalsAroundSegment(SigFlags flags)

   409

{

   410

	TileIndex tile;

   411

	Trackdir trackdir;

   412

   413

	while (_tbuset.Get(&tile, &trackdir)) {

   414

		assert(HasSignalOnTrackdir(tile, trackdir));

   415

   416

		SignalType sig = GetSignalType(tile, TrackdirToTrack(trackdir));

   417

		SignalState newstate = SIGNAL_STATE_GREEN;

   418

   419

		/* determine whether the new state is red */

   420

		if (flags & SF_TRAIN) {

   421

			/* train in the segment */

   422

			newstate = SIGNAL_STATE_RED;

   423

		} else {

   424

 			/* is it a bidir combo? - then do not count its other signal direction as exit */

   425

			if (sig == SIGTYPE_COMBO && HasSignalOnTrackdir(tile, ReverseTrackdir(trackdir))) {

   426

				/* at least one more exit */

   427

				if (flags & SF_EXIT2 &&

   428

 						/* no green exit */

   429

						(!(flags & SF_GREEN) ||

   430

						/* only one green exit, and it is this one - so all other exits are red */

   431

						(!(flags & SF_GREEN2) && GetSignalStateByTrackdir(tile, ReverseTrackdir(trackdir)) == SIGNAL_STATE_GREEN))) {

   432

					newstate = SIGNAL_STATE_RED;

   433

				}

   434

			} else { // entry, at least one exit, no green exit

   435

				if (sig & SIGTYPE_ENTRY && (flags & SF_EXIT && !(flags & SF_GREEN))) newstate = SIGNAL_STATE_RED;

   436

			}

   437

		}

   438

   439

		/* only when the state changes */

   440

		if (newstate != GetSignalStateByTrackdir(tile, trackdir)) {

   441

			if (sig & SIGTYPE_EXIT) {

   442

				/* for pre-signal exits, add block to the global set */

   443

				DiagDirection exitdir = TrackdirToExitdir(ReverseTrackdir(trackdir));

   444

				_globset.Add(tile, exitdir); // do not check for full global set, first update all signals

   445

			}

   446

			SetSignalStateByTrackdir(tile, trackdir, newstate);

   447

			MarkTileDirtyByTile(tile);

   448

		}

   449

	}

   450

   451

}

   452

   453

   454

/** Reset all sets after one set overflowed */

   455

static inline void ResetSets()

   456

{

   457

	_tbuset.Reset();

   458

	_tbdset.Reset();

   459

	_globset.Reset();

   460

}

   461

   462

   463

/**

   464

 * Updates blocks in _globset buffer

   465

 *

   466

 * @param owner player whose signals we are updating

   467

 * @return false iff presignal entry would be green (needed for trains leaving depot)

   468

 * @pre IsValidPlayer(owner)

   469

 */

   470

static bool UpdateSignalsInBuffer(Owner owner)

   471

{

   472

	assert(IsValidPlayer(owner));

   473

   474

	bool first = true;  // first block?

   475

	bool state = false; // value to return

   476

   477

	TileIndex tile;

   478

	DiagDirection dir;

   479

   480

	while (_globset.Get(&tile, &dir)) {

   481

		assert(_tbuset.IsEmpty());

   482

		assert(_tbdset.IsEmpty());

   483

   484

		/* After updating signal, data stored are always MP_RAILWAY with signals.

   485

		 * Other situations happen when data are from outside functions -

   486

		 * modification of railbits (including both rail building and removal),

   487

		 * train entering/leaving block, train leaving depot...

   488

		 */

   489

		switch (GetTileType(tile)) {

   490

			case MP_TUNNELBRIDGE:

   491

				/* 'optimization assert' - do not try to update signals when it is not needed */

   492

				assert(GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL);

   493

				assert(dir == INVALID_DIAGDIR || dir == ReverseDiagDir(GetTunnelBridgeDirection(tile)));

   494

				_tbdset.Add(tile, INVALID_DIAGDIR);  // we can safely start from wormhole centre

   495

				_tbdset.Add(GetOtherTunnelBridgeEnd(tile), INVALID_DIAGDIR);

   496

				break;

   497

   498

			case MP_RAILWAY:

   499

				if (IsRailDepot(tile)) {

   500

					/* 'optimization assert' do not try to update signals in other cases */

   501

					assert(dir == INVALID_DIAGDIR || dir == GetRailDepotDirection(tile));

   502

					_tbdset.Add(tile, INVALID_DIAGDIR); // start from depot inside

   503

					break;

   504

				}

   505

				/* FALLTHROUGH */

   506

			case MP_STATION:

   507

			case MP_ROAD:

   508

				if ((TrackBits)(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) {

   509

 					/* only add to set when there is some 'interesting' track */

   510

					_tbdset.Add(tile, dir);

   511

					_tbdset.Add(tile + TileOffsByDiagDir(dir), ReverseDiagDir(dir));

   512

					break;

   513

				}

   514

				/* FALLTHROUGH */

   515

			default:

   516

				/* jump to next tile */

   517

				tile = tile + TileOffsByDiagDir(dir);

   518

				dir = ReverseDiagDir(dir);

   519

				if ((TrackBits)(GetTileTrackStatus(tile, TRANSPORT_RAIL, 0) & _enterdir_to_trackbits[dir]) != TRACK_BIT_NONE) {

   520

					_tbdset.Add(tile, dir);

   521

					break;

   522

				}

   523

				/* happens when removing a rail that wasn't connected at one or both sides */

   524

				continue; // continue the while() loop

   525

		}

   526