1

/* $Id$ */

     2

     3

#include "stdafx.h"

     4

#include "openttd.h"

     5

#include "debug.h"

     6

#include "functions.h"

     7

#include "npf.h"

     8

#include "aystar.h"

     9

#include "macros.h"

    10

#include "pathfind.h"

    11

#include "station.h"

    12

#include "tile.h"

    13

#include "depot.h"

    14

    15

static AyStar _npf_aystar;

    16

    17

/* The cost of each trackdir. A diagonal piece is the full NPF_TILE_LENGTH,

    18

 * the shorter piece is sqrt(2)/2*NPF_TILE_LENGTH =~ 0.7071

    19

 */

    20

#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)

    21

static const uint _trackdir_length[TRACKDIR_END] = {

    22

	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH,

    23

	0, 0,

    24

	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH

    25

};

    26

    27

/**

    28

 * Calculates the minimum distance traveled to get from t0 to t1 when only

    29

 * using tracks (ie, only making 45 degree turns). Returns the distance in the

    30

 * NPF scale, ie the number of full tiles multiplied by NPF_TILE_LENGTH to

    31

 * prevent rounding.

    32

 */

    34

{

    35

	const uint dx = abs(TileX(t0) - TileX(t1));

    36

	const uint dy = abs(TileY(t0) - TileY(t1));

    37

    38

	const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */

    39

	/* OPTIMISATION:

    40

	 * Original: diagTracks = max(dx, dy) - min(dx,dy);

    41

	 * Proof:

    42

	 * (dx+dy) - straightTracks  == (min + max) - straightTracks = min + max - 2 * min = max - min */

    43

	const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */

    44

    45

	/* Don't factor out NPF_TILE_LENGTH below, this will round values and lose

    46

	 * precision */

    47

	return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;

    48

}

    49

    50

/**

    51

 * Check if a rail track is the end of the line. Will also consider 1-way signals to be the end of a line.

    52

 * @param tile The tile on which the current track is.

    53

 * @param trackdir The (track)direction in which you want to look.

    54

 * @param enginetype The type of the engine for which we are checking this.

    55

 */

    57

{

    58

	byte exitdir = TrackdirToExitdir(trackdir);

    59

	TileIndex dst_tile;

    60

	uint32 ts;

    61

    62

	/* Can always go into a tunnel */

    63

	if (IsTileType(tile, MP_TUNNELBRIDGE) && (_m[tile].m5 & 0xF0)==0 && (_m[tile].m5 & 3) == exitdir)

    64

		return false;

    65

    66

	/* Cannot go through the back of a depot */

    67

	if (IsTileDepotType(tile, TRANSPORT_RAIL) && (exitdir != GetDepotDirection(tile, TRANSPORT_RAIL)))

    68

		return true;

    69

    70

	/* Calculate next tile */

    71

	dst_tile = tile + TileOffsByDir(exitdir);

    72

	// determine the track status on the next tile.

    73

	ts = GetTileTrackStatus(dst_tile, TRANSPORT_RAIL) & TrackdirReachesTrackdirs(trackdir);

    74

    75

	// when none of the trackdir bits are set, we cant enter the new tile

    76

	if ( (ts & TRACKDIR_BIT_MASK) == 0)

    77

		return true;

    78

    79

	{

    80

		byte dst_type = GetTileRailType(dst_tile, exitdir);

    81

		if (!IsCompatibleRail(enginetype, dst_type))

    82

			return true;

    83

		if (GetTileOwner(tile) != GetTileOwner(dst_tile))

    84

			return true;

    85

    86

		/* Prevent us from entering a depot from behind */

    87

		if (IsTileDepotType(dst_tile, TRANSPORT_RAIL) && (exitdir != ReverseDiagdir(GetDepotDirection(dst_tile, TRANSPORT_RAIL))))

    88

			return true;

    89

    90

		/* Prevent us from falling off a slope into a tunnel exit */

    91

		if (IsTileType(dst_tile, MP_TUNNELBRIDGE) && (_m[dst_tile].m5 & 0xF0)==0 && (DiagDirection)(_m[dst_tile].m5 & 3) == ReverseDiagdir(exitdir))

    92

				return true;

    93

    94

		/* Check for oneway signal against us */

    95

		if (IsTileType(dst_tile, MP_RAILWAY) && GetRailTileType(dst_tile) == RAIL_TYPE_SIGNALS) {

    96

			if (HasSignalOnTrackdir(dst_tile, ReverseTrackdir(FindFirstBit2x64(ts))) && !HasSignalOnTrackdir(dst_tile, FindFirstBit2x64(ts)))

    97

				// if one way signal not pointing towards us, stop going in this direction.

    98

				return true;

    99

		}

   100

   101

		return false;

   102

	}

   103

}

   104

   105

#if 0

   106

static uint NTPHash(uint key1, uint key2)

   107

{

   108

	/* This function uses the old hash, which is fixed on 10 bits (1024 buckets) */

   109

	return PATHFIND_HASH_TILE(key1);

   110

}

   111

#endif

   112

   113

/**

   114

 * Calculates a hash value for use in the NPF.

   115

 * @param key1	The TileIndex of the tile to hash

   116

 * @param key1	The Trackdir of the track on the tile.

   117

 *

   118

 * @todo	Think of a better hash.

   119

 */

   120

static uint NPFHash(uint key1, uint key2)

   121

{

   122

	/* TODO: think of a better hash? */

   123

	uint part1 = TileX(key1) & NPF_HASH_HALFMASK;

   124

	uint part2 = TileY(key1) & NPF_HASH_HALFMASK;

   125

   126

	assert(IsValidTrackdir(key2));

   127

	assert(IsValidTile(key1));

   128

	return ((((part1 << NPF_HASH_HALFBITS) | part2)) + (NPF_HASH_SIZE * key2 / TRACKDIR_END)) % NPF_HASH_SIZE;

   129

}

   130

   131

static int32 NPFCalcZero(AyStar* as, AyStarNode* current, OpenListNode* parent)

   132

{

   133

	return 0;

   134

}

   135

   136

/* Calcs the tile of given station that is closest to a given tile

   137

 * for this we assume the station is a rectangle,

   138

 * as defined by its top tile (st->train_tile) and its width/height (st->trainst_w, st->trainst_h)

   139

 */

   140

static TileIndex CalcClosestStationTile(StationID station, TileIndex tile)

   141

{

   142

	const Station* st = GetStation(station);

   143

   144

	uint minx = TileX(st->train_tile);  // topmost corner of station

   145

	uint miny = TileY(st->train_tile);

   146

	uint maxx = minx + st->trainst_w - 1; // lowermost corner of station

   147

	uint maxy = miny + st->trainst_h - 1;

   148

	uint x;

   149

	uint y;

   150

   151

	// we are going the aim for the x coordinate of the closest corner

   152

	// but if we are between those coordinates, we will aim for our own x coordinate

   153

	x = clamp(TileX(tile), minx, maxx);

   154

   155

	// same for y coordinate, see above comment

   156

	y = clamp(TileY(tile), miny, maxy);

   157

   158

	// return the tile of our target coordinates

   159

	return TileXY(x, y);

   160

}

   161

   162

/* On PBS pathfinding runs, this is called before pathfinding ends (BeforeExit aystar callback), and will

   163

 * reserve the appropriate tracks, if needed. */

   165

{

   166

	NPFFoundTargetData* ftd = (NPFFoundTargetData*)as->user_path;

   167

	bool eol_end = false;

   168

   169

	if (ftd->best_trackdir == 0xFF)

   170

		return;

   171

   172

	if (!NPFGetFlag(&ftd->node, NPF_FLAG_PBS_EXIT) && IsEndOfLine(ftd->node.tile, ftd->node.direction, as->user_data[NPF_RAILTYPE]) && !NPFGetFlag(&ftd->node, NPF_FLAG_SEEN_SIGNAL)) {

   173

		/* The path ends in an end of line, we'll need to reserve a path.

   174

		 * We treat and end of line as a red exit signal */

   175

		eol_end = true;

   176

		NPFSetFlag(&ftd->node, NPF_FLAG_PBS_EXIT, true);

   177

		if (!NPFGetFlag(&ftd->node, NPF_FLAG_PBS_TARGET_SEEN))

   178

			NPFSetFlag(&ftd->node, NPF_FLAG_PBS_RED, true);

   179

	}

   180

   181

	if (!NPFGetFlag(&ftd->node, NPF_FLAG_PBS_CHOICE)) {

   182

		/* there have been no choices to make on our path, we dont care if our end signal is red */

   183

		NPFSetFlag(&ftd->node, NPF_FLAG_PBS_RED, false);

   184

	}

   185

   186

	if (NPFGetFlag(&ftd->node, NPF_FLAG_PBS_EXIT) && // we passed an exit signal

   187

		 !NPFGetFlag(&ftd->node, NPF_FLAG_PBS_BLOCKED) && // we didnt encounter reserver tracks

   188

		 ((as->user_data[NPF_PBS_MODE] != PBS_MODE_GREEN) || (!NPFGetFlag(&ftd->node, NPF_FLAG_PBS_RED))) ) { // our mode permits having a red exit signal, or the signal is green

   189

		PathNode parent;

   190

		PathNode *curr;

   191

		PathNode *prev;

   192

		TileIndex start = INVALID_TILE;

   193

		byte trackdir = 0;

   194

   195

		parent.node = ftd->node;

   196

		parent.parent = &ftd->path;

   197

		curr = &parent;

   198

		prev = NULL;

   199

   200

		do {

   201

			if (!NPFGetFlag(&curr->node, NPF_FLAG_PBS_EXIT) || eol_end) {

   202

				/* check for already reserved track on this path, if they clash with what we

   203

				   currently trying to reserve, we have a self-crossing path :-( */

   204

				if ((PBSTileUnavail(curr->node.tile) & (1 << curr->node.direction))

   205

				&& !(PBSTileReserved(curr->node.tile) & (1 << (curr->node.direction & 7)))

   206

				&& (start != INVALID_TILE)) {

   207

					/* It's actually quite bad if this happens, it means the pathfinder

   208

					 * found a path that is intersecting with itself, which is a very bad

   209

					 * thing in a pbs block. Also there is not much we can do about it at

   210

					 * this point....

   211

					 * BUT, you have to have a pretty fucked up junction layout for this to happen,

   212

					 * so we'll just stop this train, the user will eventually notice, so he can fix it.

   213

					 */

   214

					PBSClearPath(start, trackdir, curr->node.tile, curr->node.direction);

   215

					NPFSetFlag(&ftd->node, NPF_FLAG_PBS_BLOCKED, true);

   216

					DEBUG(pbs, 1) ("PBS: Self-crossing path!!!");

   217

					return;

   218

				};

   219

   220

				PBSReserveTrack(curr->node.tile, TrackdirToTrack(curr->node.direction) );

   221

   222

				/* we want to reserve the last tile (with the signal) on the path too

   223

				   also remember this tile, cause its the end of the path (where we exit the block) */

   224

				if (start == INVALID_TILE) {

   225

					if (prev != NULL) {

   226

						PBSReserveTrack(prev->node.tile, TrackdirToTrack(prev->node.direction) );

   227

						start = prev->node.tile;

   228

						trackdir = ReverseTrackdir(prev->node.direction);

   229

					} else {

   230

						start = curr->node.tile;

   231

						trackdir = curr->node.direction;

   232

					}

   233

				}

   234

			}

   235

   236

			prev = curr;

   237

			curr = curr->parent;

   238

		} while (curr != NULL);

   239

		// we remember the tile/track where this path leaves the pbs junction

   240

		ftd->node.tile = start;

   241

		ftd->node.direction = trackdir;

   242

	}

   243

}

   244

   245

   246

/* Calcs the heuristic to the target station or tile. For train stations, it

   247

 * takes into account the direction of approach.

   248

 */

   249

static int32 NPFCalcStationOrTileHeuristic(AyStar* as, AyStarNode* current, OpenListNode* parent)

   250

{

   251

	NPFFindStationOrTileData* fstd = (NPFFindStationOrTileData*)as->user_target;

   252

	NPFFoundTargetData* ftd = (NPFFoundTargetData*)as->user_path;

   253

	TileIndex from = current->tile;

   254

	TileIndex to = fstd->dest_coords;

   255

	uint dist;

   256

   257

	// for train-stations, we are going to aim for the closest station tile

   258

	if ((as->user_data[NPF_TYPE] == TRANSPORT_RAIL) && (fstd->station_index != -1))

   259

		to = CalcClosestStationTile(fstd->station_index, from);

   260

   261

	if (as->user_data[NPF_TYPE] == TRANSPORT_ROAD)

   262

		/* Since roads only have diagonal pieces, we use manhattan distance here */

   263

		dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;

   264

	else

   265

		/* Ships and trains can also go diagonal, so the minimum distance is shorter */

   266

		dist = NPFDistanceTrack(from, to);

   267

   268

	DEBUG(npf, 4)("Calculating H for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), dist);

   269

   270

	/* for pbs runs, we ignore tiles inside the pbs block for the tracking

   271

	   of the 'closest' tile */

   272

	if ((as->user_data[NPF_PBS_MODE] != PBS_MODE_NONE)

   273

	&&  (!NPFGetFlag(current , NPF_FLAG_SEEN_SIGNAL))

   274

	&&  (!IsEndOfLine(current->tile, current->direction, as->user_data[NPF_RAILTYPE])))

   275

		return dist;

   276

   277

	if ((dist < ftd->best_bird_dist) ||

   278

		/* for pbs runs, prefer tiles that pass a green exit signal to the pbs blocks */

   279

		((as->user_data[NPF_PBS_MODE] != PBS_MODE_NONE) && !NPFGetFlag(current, NPF_FLAG_PBS_RED) && NPFGetFlag(&ftd->node, NPF_FLAG_PBS_RED))

   280

) {

   281

		ftd->best_bird_dist = dist;

   282

		ftd->best_trackdir = current->user_data[NPF_TRACKDIR_CHOICE];

   283

		ftd->path = parent->path;

   284

		ftd->node = *current;

   285

	}

   286

	return dist;

   287

}

   288

   289

/* Fills AyStarNode.user_data[NPF_TRACKDIRCHOICE] with the chosen direction to

   290

 * get here, either getting it from the current choice or from the parent's

   291

 * choice */

   292

static void NPFFillTrackdirChoice(AyStarNode* current, OpenListNode* parent)

   293

{

   294

	if (parent->path.parent == NULL) {

   295

		Trackdir trackdir = (Trackdir)current->direction;

   296

		/* This is a first order decision, so we'd better save the

   297

		 * direction we chose */

   298

		current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;

   299

		DEBUG(npf, 6)("Saving trackdir: %#x", trackdir);

   300

	} else {

   301

		/* We've already made the decision, so just save our parent's

   302

		 * decision */

   303

		current->user_data[NPF_TRACKDIR_CHOICE] = parent->path.node.user_data[NPF_TRACKDIR_CHOICE];

   304

	}

   305

   306

}

   307

   308

/* Will return the cost of the tunnel. If it is an entry, it will return the

   309

 * cost of that tile. If the tile is an exit, it will return the tunnel length

   310

 * including the exit tile. Requires that this is a Tunnel tile */

   311

static uint NPFTunnelCost(AyStarNode* current)

   312

{

   313

	DiagDirection exitdir = TrackdirToExitdir((Trackdir)current->direction);

   314

	TileIndex tile = current->tile;

   315

	if ( (DiagDirection)(_m[tile].m5 & 3) == ReverseDiagdir(exitdir)) {

   316

		/* We just popped out if this tunnel, since were

   317

		 * facing the tunnel exit */

   318

		FindLengthOfTunnelResult flotr;

   319

		flotr = FindLengthOfTunnel(tile, ReverseDiagdir(exitdir));

   320

		return flotr.length * NPF_TILE_LENGTH;

   321

		//TODO: Penalty for tunnels?

   322

	} else {

   323

		/* We are entering the tunnel, the enter tile is just a

   324

		 * straight track */

   325

		return NPF_TILE_LENGTH;

   326

	}

   327

}

   328

   329

static uint NPFSlopeCost(AyStarNode* current)

   330

{

   331

	TileIndex next = current->tile + TileOffsByDir(TrackdirToExitdir(current->direction));

   332

	int x,y;

   333

	int8 z1,z2;

   334

   335

	x = TileX(current->tile) * TILE_SIZE;

   336

	y = TileY(current->tile) * TILE_SIZE;

   337

	/* get the height of the center of the current tile */

   338

	z1 = GetSlopeZ(x+TILE_HEIGHT, y+TILE_HEIGHT);

   339

   340

	x = TileX(next) * TILE_SIZE;

   341

	y = TileY(next) * TILE_SIZE;

   342

	/* get the height of the center of the next tile */

   343

	z2 = GetSlopeZ(x+TILE_HEIGHT, y+TILE_HEIGHT);

   344

   345

	if ((z2 - z1) > 1) {

   346

		/* Slope up */

   347

		return _patches.npf_rail_slope_penalty;

   348

	}

   349

	return 0;

   350

	/* Should we give a bonus for slope down? Probably not, we

   351

	 * could just substract that bonus from the penalty, because

   352

	 * there is only one level of steepness... */

   353

}

   354

   355

/* Mark tiles by mowing the grass when npf debug level >= 1 */

   356

static void NPFMarkTile(TileIndex tile)

   357

{

   358

#ifdef NO_DEBUG_MESSAGES

   359

	return;

   360

#else

   361

	if (_debug_npf_level >= 1)

   362

		switch(GetTileType(tile)) {

   363

			case MP_RAILWAY:

   364

				/* DEBUG: mark visited tiles by mowing the grass under them

   365

				 * ;-) */

   366

				if (!IsTileDepotType(tile, TRANSPORT_RAIL)) {

   367

					_m[tile].m2 &= ~15; /* Clear bits 0-3 */

   368

					MarkTileDirtyByTile(tile);

   369

				}

   370

				break;

   371

			case MP_STREET:

   372

				if (!IsTileDepotType(tile, TRANSPORT_ROAD)) {

   373

					_m[tile].m4 &= ~0x70; /* Clear bits 4-6 */

   374

					MarkTileDirtyByTile(tile);

   375

				}

   376

				break;

   377

			default:

   378

				break;

   379

		}

   380

#endif

   381

}

   382

   383

static int32 NPFWaterPathCost(AyStar* as, AyStarNode* current, OpenListNode* parent)

   384

{

   385

	//TileIndex tile = current->tile;

   386

	int32 cost = 0;

   387

	Trackdir trackdir = (Trackdir)current->direction;

   388

   389

	cost = _trackdir_length[trackdir]; /* Should be different for diagonal tracks */

   390

   391

	if (IsBuoyTile(current->tile) && IsDiagonalTrackdir(trackdir))

   392

		cost += _patches.npf_buoy_penalty; /* A small penalty for going over buoys */

   393

   394

	if (current->direction != NextTrackdir((Trackdir)parent->path.node.direction))

   395

		cost += _patches.npf_water_curve_penalty;

   396

   397

	/* TODO More penalties? */

   398

   399

	return cost;

   400

}

   401

   402

/* Determine the cost of this node, for road tracks */

   403

static int32 NPFRoadPathCost(AyStar* as, AyStarNode* current, OpenListNode* parent)

   404

{

   405

	TileIndex tile = current->tile;

   406

	int32 cost = 0;

   407

   408

	/* Determine base length */

   409

	switch (GetTileType(tile)) {

   410

		case MP_TUNNELBRIDGE:

   411

			if ((_m[tile].m5 & 0xF0)==0) {

   412

				cost = NPFTunnelCost(current);

   413

				break;

   414

			}

   415

			/* Fall through if above if is false, it is a bridge

   416

			 * then. We treat that as ordinary road */

   417

		case MP_STREET:

   418

			cost = NPF_TILE_LENGTH;

   419

			/* Increase the cost for level crossings */

   420

			if ((_m[tile].m5 & 0xF0) == 0x10)

   421

				cost += _patches.npf_crossing_penalty;

   422

			break;

   423

		default:

   424

			break;

   425

	}

   426

   427

	/* Determine extra costs */

   428

   429

	/* Check for slope */

   430

	cost += NPFSlopeCost(current);

   431

   432

	/* Check for turns. Road vehicles only really drive diagonal, turns are

   433

	 * represented by non-diagonal tracks */

   434

	if (!IsDiagonalTrackdir(current->direction))

   435

		cost += _patches.npf_road_curve_penalty;

   436

   437

	NPFMarkTile(tile);

   438

	DEBUG(npf, 4)("Calculating G for: (%d, %d). Result: %d", TileX(current->tile), TileY(current->tile), cost);

   439

	return cost;

   440

}

   441

   442

   443

/* Determine the cost of this node, for railway tracks */

   444

static int32 NPFRailPathCost(AyStar* as, AyStarNode* current, OpenListNode* parent)

   445

{

   446

	TileIndex tile = current->tile;

   447

	Trackdir trackdir = (Trackdir)current->direction;

   448

	int32 cost = 0;

   449

	/* HACK: We create a OpenListNode manualy, so we can call EndNodeCheck */

   450

	OpenListNode new_node;

   451

   452

	/* Determine base length */

   453

	switch (GetTileType(tile)) {

   454

		case MP_TUNNELBRIDGE:

   455

			if ((_m[tile].m5 & 0xF0)==0) {

   456

				cost = NPFTunnelCost(current);

   457

				break;

   458

			}

   459

			/* Fall through if above if is false, it is a bridge

   460

			 * then. We treat that as ordinary rail */

   461

		case MP_RAILWAY:

   462

			cost = _trackdir_length[trackdir]; /* Should be different for diagonal tracks */

   463

			break;

   464

		case MP_STREET: /* Railway crossing */

   465

			cost = NPF_TILE_LENGTH;

   466

			break;

   467

		case MP_STATION:

   468

			/* We give a station tile a penalty. Logically we would only

   469

					* want to give station tiles that are not our destination

   470

					* this penalty. This would discourage trains to drive through

   471

					* busy stations. But, we can just give any station tile a

   472

					* penalty, because every possible route will get this penalty

   473

					* exactly once, on its end tile (if it's a station) and it

   474

			* will therefore not make a difference. */

   475

			cost = NPF_TILE_LENGTH + _patches.npf_rail_station_penalty;

   476

			break;

   477

		default:

   478

			break;

   479

	}

   480

   481

	/* Determine extra costs */

   482

   483

	/* Check for reserved tracks (PBS) */

   484

	if ((as->user_data[NPF_PBS_MODE] != PBS_MODE_NONE) && !(NPFGetFlag(current, NPF_FLAG_PBS_EXIT)) && !(NPFGetFlag(current, NPF_FLAG_PBS_BLOCKED)) && (PBSTileUnavail(tile) & (1<<trackdir))) {

   485

		NPFSetFlag(current, NPF_FLAG_PBS_BLOCKED, true);

   486

	};

   487

   488

	/* Check for signals */

   489

	if (IsTileType(tile, MP_RAILWAY) && HasSignalOnTrackdir(tile, trackdir)) {

   490

		/* Ordinary track with signals */

   491

		if (GetSignalState(tile, trackdir) == SIGNAL_STATE_RED) {

   492

			/* Signal facing us is red */

   493

			if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {

   494