1

/* $Id$ */

     2

     3

/** @file npf.cpp Implementation of the NPF pathfinder. */

     4

     5

#include "stdafx.h"

     6

#include "openttd.h"

     7

#include "npf.h"

     8

#include "bridge_map.h"

     9

#include "debug.h"

    10

#include "tile_cmd.h"

    11

#include "bridge.h"

    12

#include "landscape.h"

    13

#include "aystar.h"

    14

#include "pathfind.h"

    15

#include "station_base.h"

    16

#include "station_map.h"

    17

#include "depot_base.h"

    18

#include "depot_map.h"

    19

#include "tunnel_map.h"

    20

#include "network/network.h"

    21

#include "water_map.h"

    22

#include "tunnelbridge_map.h"

    23

#include "functions.h"

    24

#include "vehicle_base.h"

    25

#include "settings_type.h"

    26

#include "tunnelbridge.h"

    27

    28

static AyStar _npf_aystar;

    29

    30

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

    31

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

    32

 */

    33

#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)

    34

static const uint _trackdir_length[TRACKDIR_END] = {

    35

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

    36

	0, 0,

    37

	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH

    38

};

    39

    40

/**

    41

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

    42

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

    43

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

    44

 * prevent rounding.

    45

 */

    46

static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)

    47

{

    48

	const uint dx = Delta(TileX(t0), TileX(t1));

    49

	const uint dy = Delta(TileY(t0), TileY(t1));

    50

    51

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

    52

	/* OPTIMISATION:

    53

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

    54

	 * Proof:

    55

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

    56

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

    57

    58

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

    59

	 * precision */

    60

	return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;

    61

}

    62

    63

    64

#if 0

    65

static uint NTPHash(uint key1, uint key2)

    66

{

    67

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

    68

	return PATHFIND_HASH_TILE(key1);

    69

}

    70

#endif

    71

    72

/**

    73

 * Calculates a hash value for use in the NPF.

    74

 * @param key1 The TileIndex of the tile to hash

    75

 * @param key2 The Trackdir of the track on the tile.

    76

 *

    77

 * @todo Think of a better hash.

    78

 */

    79

static uint NPFHash(uint key1, uint key2)

    80

{

    81

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

    82

	uint part1 = TileX(key1) & NPF_HASH_HALFMASK;

    83

	uint part2 = TileY(key1) & NPF_HASH_HALFMASK;

    84

    85

	assert(IsValidTrackdir((Trackdir)key2));

    86

	assert(IsValidTile(key1));

    87

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

    88

}

    89

    90

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

    91

{

    92

	return 0;

    93

}

    94

    95

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

    96

 * for this we assume the station is a rectangle,

    97

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

    98

 */

    99

static TileIndex CalcClosestStationTile(StationID station, TileIndex tile)

   100

{

   101

	const Station* st = GetStation(station);

   102

   103

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

   104

	uint miny = TileY(st->train_tile);

   105

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

   106

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

   107

	uint x;

   108

	uint y;

   109

   110

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

   111

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

   112

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

   113

   114

	/* same for y coordinate, see above comment */

   115

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

   116

   117

	/* return the tile of our target coordinates */

   118

	return TileXY(x, y);

   119

}

   120

   121

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

   122

 * takes into account the direction of approach.

   123

 */

   124

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

   125

{

   126

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

   127

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

   128

	TileIndex from = current->tile;

   129

	TileIndex to = fstd->dest_coords;

   130

	uint dist;

   131

   132

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

   133

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

   134

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

   135

   136

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

   137

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

   138

		dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;

   139

	} else {

   140

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

   141

		dist = NPFDistanceTrack(from, to);

   142

	}

   143

   144

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

   145

   146

	if (dist < ftd->best_bird_dist) {

   147

		ftd->best_bird_dist = dist;

   148

		ftd->best_trackdir = (Trackdir)current->user_data[NPF_TRACKDIR_CHOICE];

   149

	}

   150

	return dist;

   151

}

   152

   153

   154

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

   155

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

   156

 * choice */

   157

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

   158

{

   159

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

   160

		Trackdir trackdir = (Trackdir)current->direction;

   161

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

   162

		 * direction we chose */

   163

		current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;

   164

		DEBUG(npf, 6, "Saving trackdir: 0x%X", trackdir);

   165

	} else {

   166

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

   167

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

   168

	}

   169

}

   170

   171

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

   172

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

   173

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

   174

static uint NPFTunnelCost(AyStarNode* current)

   175

{

   176

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

   177

	TileIndex tile = current->tile;

   178

	if (GetTunnelBridgeDirection(tile) == ReverseDiagDir(exitdir)) {

   179

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

   180

		 * facing the tunnel exit */

   181

		return NPF_TILE_LENGTH * (GetTunnelBridgeLength(current->tile, GetOtherTunnelEnd(current->tile)) + 1);

   182

		/* @todo: Penalty for tunnels? */

   183

	} else {

   184

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

   185

		 * straight track */

   186

		return NPF_TILE_LENGTH;

   187

	}

   188

}

   189

   190

static inline uint NPFBridgeCost(AyStarNode *current)

   191

{

   192

	return NPF_TILE_LENGTH * GetTunnelBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));

   193

}

   194

   195

static uint NPFSlopeCost(AyStarNode* current)

   196

{

   197

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

   198

   199

	/* Get center of tiles */

   200

	int x1 = TileX(current->tile) * TILE_SIZE + TILE_SIZE / 2;

   201

	int y1 = TileY(current->tile) * TILE_SIZE + TILE_SIZE / 2;

   202

	int x2 = TileX(next) * TILE_SIZE + TILE_SIZE / 2;

   203

	int y2 = TileY(next) * TILE_SIZE + TILE_SIZE / 2;

   204

   205

	int dx4 = (x2 - x1) / 4;

   206

	int dy4 = (y2 - y1) / 4;

   207

   208

	/* Get the height on both sides of the tile edge.

   209

	 * Avoid testing the height on the tile-center. This will fail for halftile-foundations.

   210

	 */

   211

	int z1 = GetSlopeZ(x1 + dx4, y1 + dy4);

   212

	int z2 = GetSlopeZ(x2 - dx4, y2 - dy4);

   213

   214

	if (z2 - z1 > 1) {

   215

		/* Slope up */

   217

	}

   218

	return 0;

   219

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

   220

	 * could just substract that bonus from the penalty, because

   221

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

   222

}

   223

   224

/**

   225

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

   226

 * Will not work for multiplayer games, since it can (will) cause desyncs.

   227

 */

   228

static void NPFMarkTile(TileIndex tile)

   229

{

   230

#ifndef NO_DEBUG_MESSAGES

   231

	if (_debug_npf_level < 1 || _networking) return;

   232

	switch (GetTileType(tile)) {

   233

		case MP_RAILWAY:

   234

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

   235

			if (!IsRailDepot(tile)) {

   236

				SetRailGroundType(tile, RAIL_GROUND_BARREN);

   237

				MarkTileDirtyByTile(tile);

   238

			}

   239

			break;

   240

   241

		case MP_ROAD:

   242

			if (!IsRoadDepot(tile)) {

   243

				SetRoadside(tile, ROADSIDE_BARREN);

   244

				MarkTileDirtyByTile(tile);

   245

			}

   246

			break;

   247

   248

		default:

   249

			break;

   250

	}

   251

#endif

   252

}

   253

   254

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

   255

{

   256

	/* TileIndex tile = current->tile; */

   257

	int32 cost = 0;

   258

	Trackdir trackdir = (Trackdir)current->direction;

   259

   260

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

   261

   262

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

   264

   265

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

   267

   268

	/* @todo More penalties? */

   269

   270

	return cost;

   271

}

   272

   273

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

   274

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

   275

{

   276

	TileIndex tile = current->tile;

   277

	int32 cost = 0;

   278

   279

	/* Determine base length */

   280

	switch (GetTileType(tile)) {

   281

		case MP_TUNNELBRIDGE:

   282

			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);

   283

			break;

   284

   285

		case MP_ROAD:

   286

			cost = NPF_TILE_LENGTH;

   287

			/* Increase the cost for level crossings */

   289

			break;

   290

   291

		case MP_STATION:

   292

			cost = NPF_TILE_LENGTH;

   293

			/* Increase the cost for drive-through road stops */

   295

			break;

   296

   297

		default:

   298

			break;

   299

	}

   300

   301

	/* Determine extra costs */

   302

   303

	/* Check for slope */

   304

	cost += NPFSlopeCost(current);

   305

   306

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

   307

	 * represented by non-diagonal tracks */

   308

	if (!IsDiagonalTrackdir((Trackdir)current->direction))

   310

   311

	NPFMarkTile(tile);

   312

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

   313

	return cost;

   314

}

   315

   316

   317

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

   318

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

   319

{

   320

	TileIndex tile = current->tile;

   321

	Trackdir trackdir = (Trackdir)current->direction;

   322

	int32 cost = 0;

   323

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

   324

	OpenListNode new_node;

   325

   326

	/* Determine base length */

   327

	switch (GetTileType(tile)) {

   328

		case MP_TUNNELBRIDGE:

   329

			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);

   330

			break;

   331

   332

		case MP_RAILWAY:

   333

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

   334

			break;

   335

   336

		case MP_ROAD: /* Railway crossing */

   337

			cost = NPF_TILE_LENGTH;

   338

			break;

   339

   340

		case MP_STATION:

   341

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

   342

			 * station tiles that are not our destination this penalty. This would

   343

			 * discourage trains to drive through busy stations. But, we can just

   344

			 * give any station tile a penalty, because every possible route will get

   345

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

   346

			 * will therefore not make a difference. */

   348

			break;

   349

   350

		default:

   351

			break;

   352

	}

   353

   354

	/* Determine extra costs */

   355

   356

	/* Check for signals */

   357

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

   358

		/* Ordinary track with signals */

   359

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

   360

			/* Signal facing us is red */

   361

			if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {

   362

				/* Penalize the first signal we

   363

				 * encounter, if it is red */

   364

   365

				/* Is this a presignal exit or combo? */

   366

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

   367

				if (sigtype == SIGTYPE_EXIT || sigtype == SIGTYPE_COMBO) {

   368

					/* Penalise exit and combo signals differently (heavier) */

   370

				} else {

   372

				}

   373

			}

   374

			/* Record the state of this signal */

   375

			NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, true);

   376

		} else {

   377

			/* Record the state of this signal */

   378

			NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);

   379

		}

   380

		NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);

   381

	}

   382

   383

	/* Penalise the tile if it is a target tile and the last signal was

   384

	 * red */

   385

	/* HACK: We create a new_node here so we can call EndNodeCheck. Ugly as hell

   386

	 * of course... */

   387

	new_node.path.node = *current;

   388

	if (as->EndNodeCheck(as, &new_node) == AYSTAR_FOUND_END_NODE && NPFGetFlag(current, NPF_FLAG_LAST_SIGNAL_RED))

   390

   391

	/* Check for slope */

   392

	cost += NPFSlopeCost(current);

   393

   394

	/* Check for turns */

   395

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

   397

	/*TODO, with realistic acceleration, also the amount of straight track between

   398

	 *      curves should be taken into account, as this affects the speed limit. */

   399

   400

	/* Check for reverse in depot */

   401

	if (IsRailDepotTile(tile) && as->EndNodeCheck(as, &new_node) != AYSTAR_FOUND_END_NODE) {

   402

		/* Penalise any depot tile that is not the last tile in the path. This

   403

		 * _should_ penalise every occurence of reversing in a depot (and only

   404

		 * that) */

   406

	}

   407

   408

	/* Check for occupied track */

   409

	//TODO

   410

   411

	NPFMarkTile(tile);

   412

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

   413

	return cost;

   414

}

   415

   416

/* Will find any depot */

   417

static int32 NPFFindDepot(AyStar* as, OpenListNode *current)

   418

{

   419

	/* It's not worth caching the result with NPF_FLAG_IS_TARGET here as below,

   420

	 * since checking the cache not that much faster than the actual check */

   421

	return IsDepotTypeTile(current->path.node.tile, (TransportType)as->user_data[NPF_TYPE]) ?

   422

		AYSTAR_FOUND_END_NODE : AYSTAR_DONE;

   423

}

   424

   425

/* Will find a station identified using the NPFFindStationOrTileData */

   426

static int32 NPFFindStationOrTile(AyStar* as, OpenListNode *current)

   427

{

   428

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

   429

	AyStarNode *node = &current->path.node;

   430

	TileIndex tile = node->tile;

   431

   432

	/* If GetNeighbours said we could get here, we assume the station type

   433

	 * is correct */

   434

	if (

   435

		(fstd->station_index == INVALID_STATION && tile == fstd->dest_coords) || /* We've found the tile, or */

   436

		(IsTileType(tile, MP_STATION) && GetStationIndex(tile) == fstd->station_index) /* the station */

   437

	) {

   438

		return AYSTAR_FOUND_END_NODE;

   439

	} else {

   440

		return AYSTAR_DONE;

   441

	}

   442

}

   443

   444

/* To be called when current contains the (shortest route to) the target node.

   445

 * Will fill the contents of the NPFFoundTargetData using

   446

 * AyStarNode[NPF_TRACKDIR_CHOICE].

   447

 */

   448

static void NPFSaveTargetData(AyStar* as, OpenListNode* current)

   449

{

   450

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

   451

	ftd->best_trackdir = (Trackdir)current->path.node.user_data[NPF_TRACKDIR_CHOICE];

   452

	ftd->best_path_dist = current->g;

   453

	ftd->best_bird_dist = 0;

   454

	ftd->node = current->path.node;

   455

}

   456

   457

/**

   458

 * Finds out if a given player's vehicles are allowed to enter a given tile.

   459

 * @param owner    The owner of the vehicle.

   460

 * @param tile     The tile that is about to be entered.

   461

 * @param enterdir The direction in which the vehicle wants to enter the tile.

   462

 * @return         true if the vehicle can enter the tile.

   463

 * @todo           This function should be used in other places than just NPF,

   464

 *                 maybe moved to another file too.

   465

 */

   466

static bool CanEnterTileOwnerCheck(Owner owner, TileIndex tile, DiagDirection enterdir)

   467

{

   468

	if (IsTileType(tile, MP_RAILWAY) ||             /* Rail tile (also rail depot) */

   469

			IsRailwayStationTile(tile) ||   /* Rail station tile */

   470

			IsRoadDepotTile(tile) ||        /* Road depot tile */

   471

			IsStandardRoadStopTile(tile)) { /* Road station tile (but not drive-through stops) */

   472

		return IsTileOwner(tile, owner); /* You need to own these tiles entirely to use them */

   473

	}

   474

   475

	switch (GetTileType(tile)) {

   476

		case MP_ROAD:

   477

			/* rail-road crossing : are we looking at the railway part? */

   478

			if (IsLevelCrossing(tile) &&

   479

					DiagDirToAxis(enterdir) != GetCrossingRoadAxis(tile)) {

   480

				return IsTileOwner(tile, owner); /* Railway needs owner check, while the street is public */

   481

			}

   482

			break;

   483

   484

		case MP_TUNNELBRIDGE:

   485

			if (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) {

   486

				return IsTileOwner(tile, owner);

   487

			}