1

/* $Id$ */

     2

     3

/** @file npf.cpp */

     4

     5

#include "stdafx.h"

     6

#include "openttd.h"

     7

#include "bridge_map.h"

     8

#include "debug.h"

     9

#include "functions.h"

    10

#include "landscape.h"

    11

#include "npf.h"

    12

#include "aystar.h"

    13

#include "macros.h"

    14

#include "pathfind.h"

    15

#include "station.h"

    16

#include "station_map.h"

    17

#include "tile.h"

    18

#include "depot.h"

    19

#include "tunnel_map.h"

    20

#include "network/network.h"

    21

#include "water_map.h"

    22

    23

static AyStar _npf_aystar;

    24

    25

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

    26

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

    27

 */

    28

#define NPF_STRAIGHT_LENGTH (uint)(NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH)

    29

static const uint _trackdir_length[TRACKDIR_END] = {

    30

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

    31

	0, 0,

    32

	NPF_TILE_LENGTH, NPF_TILE_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH, NPF_STRAIGHT_LENGTH

    33

};

    34

    35

/**

    36

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

    37

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

    38

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

    39

 * prevent rounding.

    40

 */

    41

static uint NPFDistanceTrack(TileIndex t0, TileIndex t1)

    42

{

    43

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

    44

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

    45

    46

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

    47

	/* OPTIMISATION:

    48

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

    49

	 * Proof:

    50

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

    51

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

    52

    53

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

    54

	 * precision */

    55

	return diagTracks * NPF_TILE_LENGTH + straightTracks * NPF_TILE_LENGTH * STRAIGHT_TRACK_LENGTH;

    56

}

    57

    58

    59

#if 0

    60

static uint NTPHash(uint key1, uint key2)

    61

{

    62

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

    63

	return PATHFIND_HASH_TILE(key1);

    64

}

    65

#endif

    66

    67

/**

    68

 * Calculates a hash value for use in the NPF.

    69

 * @param key1 The TileIndex of the tile to hash

    70

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

    71

 *

    72

 * @todo Think of a better hash.

    73

 */

    74

static uint NPFHash(uint key1, uint key2)

    75

{

    76

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

    77

	uint part1 = TileX(key1) & NPF_HASH_HALFMASK;

    78

	uint part2 = TileY(key1) & NPF_HASH_HALFMASK;

    79

    80

	assert(IsValidTrackdir((Trackdir)key2));

    81

	assert(IsValidTile(key1));

    82

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

    83

}

    84

    85

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

    86

{

    87

	return 0;

    88

}

    89

    90

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

    91

 * for this we assume the station is a rectangle,

    92

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

    93

 */

    94

static TileIndex CalcClosestStationTile(StationID station, TileIndex tile)

    95

{

    96

	const Station* st = GetStation(station);

    97

    98

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

    99

	uint miny = TileY(st->train_tile);

   100

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

   101

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

   102

	uint x;

   103

	uint y;

   104

   105

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

   106

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

   107

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

   108

   109

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

   110

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

   111

   112

	/* return the tile of our target coordinates */

   113

	return TileXY(x, y);

   114

}

   115

   116

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

   117

 * takes into account the direction of approach.

   118

 */

   119

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

   120

{

   121

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

   122

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

   123

	TileIndex from = current->tile;

   124

	TileIndex to = fstd->dest_coords;

   125

	uint dist;

   126

   127

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

   128

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

   129

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

   130

   131

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

   132

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

   133

		dist = DistanceManhattan(from, to) * NPF_TILE_LENGTH;

   134

	} else {

   135

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

   136

		dist = NPFDistanceTrack(from, to);

   137

	}

   138

   139

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

   140

   141

	if (dist < ftd->best_bird_dist) {

   142

		ftd->best_bird_dist = dist;

   143

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

   144

	}

   145

	return dist;

   146

}

   147

   148

   149

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

   150

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

   151

 * choice */

   152

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

   153

{

   154

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

   155

		Trackdir trackdir = (Trackdir)current->direction;

   156

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

   157

		 * direction we chose */

   158

		current->user_data[NPF_TRACKDIR_CHOICE] = trackdir;

   159

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

   160

	} else {

   161

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

   162

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

   163

	}

   164

}

   165

   166

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

   167

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

   168

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

   169

static uint NPFTunnelCost(AyStarNode* current)

   170

{

   171

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

   172

	TileIndex tile = current->tile;

   173

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

   174

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

   175

		 * facing the tunnel exit */

   176

		FindLengthOfTunnelResult flotr;

   177

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

   178

		return flotr.length * NPF_TILE_LENGTH;

   179

		/* @todo: Penalty for tunnels? */

   180

	} else {

   181

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

   182

		 * straight track */

   183

		return NPF_TILE_LENGTH;

   184

	}

   185

}

   186

   187

static inline uint NPFBridgeCost(AyStarNode *current)

   188

{

   189

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

   190

}

   191

   192

static uint NPFSlopeCost(AyStarNode* current)

   193

{

   194

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

   195

   196

	/* Get center of tiles */

   197

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

   198

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

   199

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

   200

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

   201

   202

	int dx4 = (x2 - x1) / 4;

   203

	int dy4 = (y2 - y1) / 4;

   204

   205

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

   206

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

   207

	 */

   208

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

   209

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

   210

   211

	if (z2 - z1 > 1) {

   212

		/* Slope up */

   213

		return _patches.npf_rail_slope_penalty;

   214

	}

   215

	return 0;

   216

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

   217

	 * could just substract that bonus from the penalty, because

   218

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

   219

}

   220

   221

/**

   222

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

   223

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

   224

 */

   225

static void NPFMarkTile(TileIndex tile)

   226

{

   227

#ifndef NO_DEBUG_MESSAGES

   228

	if (_debug_npf_level < 1 || _networking) return;

   229

	switch (GetTileType(tile)) {

   230

		case MP_RAILWAY:

   231

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

   232

			if (!IsTileDepotType(tile, TRANSPORT_RAIL)) {

   233

				SetRailGroundType(tile, RAIL_GROUND_BARREN);

   234

				MarkTileDirtyByTile(tile);

   235

			}

   236

			break;

   237

   238

		case MP_ROAD:

   239

			if (!IsTileDepotType(tile, TRANSPORT_ROAD)) {

   240

				SetRoadside(tile, ROADSIDE_BARREN);

   241

				MarkTileDirtyByTile(tile);

   242

			}

   243

			break;

   244

   245

		default:

   246

			break;

   247

	}

   248

#endif

   249

}

   250

   251

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

   252

{

   253

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

   254

	int32 cost = 0;

   255

	Trackdir trackdir = (Trackdir)current->direction;

   256

   257

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

   258

   259

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

   260

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

   261

   262

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

   263

		cost += _patches.npf_water_curve_penalty;

   264

   265

	/* @todo More penalties? */

   266

   267

	return cost;

   268

}

   269

   270

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

   271

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

   272

{

   273

	TileIndex tile = current->tile;

   274

	int32 cost = 0;

   275

   276

	/* Determine base length */

   277

	switch (GetTileType(tile)) {

   278

		case MP_TUNNELBRIDGE:

   279

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

   280

			break;

   281

   282

		case MP_ROAD:

   283

			cost = NPF_TILE_LENGTH;

   284

			/* Increase the cost for level crossings */

   285

			if (IsLevelCrossing(tile)) cost += _patches.npf_crossing_penalty;

   286

			break;

   287

   288

		case MP_STATION:

   289

			cost = NPF_TILE_LENGTH;

   290

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

   291

			if (IsDriveThroughStopTile(tile)) cost += _patches.npf_road_drive_through_penalty;

   292

			break;

   293

   294

		default:

   295

			break;

   296

	}

   297

   298

	/* Determine extra costs */

   299

   300

	/* Check for slope */

   301

	cost += NPFSlopeCost(current);

   302

   303

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

   304

	 * represented by non-diagonal tracks */

   305

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

   306

		cost += _patches.npf_road_curve_penalty;

   307

   308

	NPFMarkTile(tile);

   309

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

   310

	return cost;

   311

}

   312

   313

   314

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

   315

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

   316

{

   317

	TileIndex tile = current->tile;

   318

	Trackdir trackdir = (Trackdir)current->direction;

   319

	int32 cost = 0;

   320

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

   321

	OpenListNode new_node;

   322

   323

	/* Determine base length */

   324

	switch (GetTileType(tile)) {

   325

		case MP_TUNNELBRIDGE:

   326

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

   327

			break;

   328

   329

		case MP_RAILWAY:

   330

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

   331

			break;

   332

   333

		case MP_ROAD: /* Railway crossing */

   334

			cost = NPF_TILE_LENGTH;

   335

			break;

   336

   337

		case MP_STATION:

   338

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

   339

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

   340

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

   341

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

   342

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

   343

			 * will therefore not make a difference. */

   344

			cost = NPF_TILE_LENGTH + _patches.npf_rail_station_penalty;

   345

			break;

   346

   347

		default:

   348

			break;

   349

	}

   350

   351

	/* Determine extra costs */

   352

   353

	/* Check for signals */

   354

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

   355

		/* Ordinary track with signals */

   356

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

   357

			/* Signal facing us is red */

   358

			if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {

   359

				/* Penalize the first signal we

   360

				 * encounter, if it is red */

   361

   362

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

   363

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

   364

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

   365

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

   366

					cost += _patches.npf_rail_firstred_exit_penalty;

   367

				} else {

   368

					cost += _patches.npf_rail_firstred_penalty;

   369

				}

   370

			}

   371

			/* Record the state of this signal */

   372

			NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, true);

   373

		} else {

   374

			/* Record the state of this signal */

   375

			NPFSetFlag(current, NPF_FLAG_LAST_SIGNAL_RED, false);

   376

		}

   377

		NPFSetFlag(current, NPF_FLAG_SEEN_SIGNAL, true);

   378

	}

   379

   380

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

   381

	 * red */

   382

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

   383

	 * of course... */

   384

	new_node.path.node = *current;

   385

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

   386

		cost += _patches.npf_rail_lastred_penalty;

   387

   388

	/* Check for slope */

   389

	cost += NPFSlopeCost(current);

   390

   391

	/* Check for turns */

   392

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

   393

		cost += _patches.npf_rail_curve_penalty;

   394

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

   395

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

   396

   397

	/* Check for reverse in depot */

   398

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

   399

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

   400

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

   401

		 * that) */

   402

		cost += _patches.npf_rail_depot_reverse_penalty;

   403

	}

   404

   405

	/* Check for occupied track */

   406

	//TODO

   407

   408

	NPFMarkTile(tile);

   409

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

   410

	return cost;

   411

}

   412

   413

/* Will find any depot */

   414

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

   415

{

   416

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

   417

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

   418

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

   419

		AYSTAR_FOUND_END_NODE : AYSTAR_DONE;

   420

}

   421

   422

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

   423

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

   424

{

   425

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

   426

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

   427

	TileIndex tile = node->tile;

   428

   429

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

   430

	 * is correct */

   431

	if (

   432

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

   433

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

   434

	) {

   435

		return AYSTAR_FOUND_END_NODE;

   436

	} else {

   437

		return AYSTAR_DONE;

   438

	}

   439

}

   440

   441

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

   442

 * Will fill the contents of the NPFFoundTargetData using

   443

 * AyStarNode[NPF_TRACKDIR_CHOICE].

   444

 */

   445

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

   446

{

   447

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

   448

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

   449

	ftd->best_path_dist = current->g;

   450

	ftd->best_bird_dist = 0;

   451

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

   452

}

   453

   454

/**

   455

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

   456

 * @param owner    The owner of the vehicle.

   457

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

   458

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

   459

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

   460

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

   461

 *                 maybe moved to another file too.

   462

 */

   463

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

   464

{

   465

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

   466

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

   467

			IsTileDepotType(tile, TRANSPORT_ROAD) ||  /* Road depot tile */

   468

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

   469

			IsTileDepotType(tile, TRANSPORT_WATER)) { /* Water depot tile */

   470

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

   471

	}

   472

   473

	switch (GetTileType(tile)) {

   474

		case MP_ROAD:

   475

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

   476

			if (IsLevelCrossing(tile) &&

   477

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

   478

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

   479

			}

   480

			break;

   481

   482

		case MP_TUNNELBRIDGE:

   483

			if ((IsTunnel(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) ||

   484

					(IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL)) {

   485

				return IsTileOwner(tile, owner);

   486

			}

   487

			break;

   488

   489

		default: