1

#include "stdafx.h"

     2

#include "ttd.h"

     3

#include "table/strings.h"

     4

#include "gfx.h"

     5

#include "map.h"

     6

#include "tile.h"

     7

#include "vehicle.h"

     8

#include "viewport.h"

     9

#include "command.h"

    10

#include "pathfind.h"

    11

#include "town.h"

    12

#include "sound.h"

    13

#include "station.h"

    14

#include "sprite.h"

    15

#include "depot.h"

    16

    17

extern uint16 _custom_sprites_base;

    18

    19

void ShowTrainDepotWindow(uint tile);

    20

    21

enum { /* These values are bitmasks for the map5 byte */

    22

	RAIL_TYPE_NORMAL = 0,

    23

	RAIL_TYPE_SIGNALS = 0x40,

    24

	RAIL_TYPE_SPECIAL = 0x80, // If this bit is set, then it's not a regular track.

    25

	RAIL_TYPE_DEPOT = 0xC0,

    26

	RAIL_TYPE_MASK = 0xC0,

    27

    28

	RAIL_BIT_DIAG1 = 1,  // 0

    29

	RAIL_BIT_DIAG2 = 2,  // 1

    30

	RAIL_BIT_UPPER = 4,  // 2

    31

	RAIL_BIT_LOWER = 8,  // 3

    32

	RAIL_BIT_LEFT  = 16, // 4

    33

	RAIL_BIT_RIGHT = 32, // 5

    34

	RAIL_BIT_MASK = 0x3F,

    35

    36

	RAIL_DEPOT_TRACK_MASK = 1,

    37

	RAIL_DEPOT_DIR = 3,

    38

	RAIL_DEPOT_UNUSED_BITS = 0x3C,

    39

    40

	RAIL_TYPE_WAYPOINT = 0xC4,

    41

	RAIL_WAYPOINT_TRACK_MASK = 1,

    42

	RAIL_WAYPOINT_UNUSED_BITS = 0x3E,

    43

};

    44

    45

#define IS_RAIL_DEPOT(x) (((x) & (RAIL_TYPE_DEPOT|RAIL_DEPOT_UNUSED_BITS)) == RAIL_TYPE_DEPOT)

    46

#define IS_RAIL_WAYPOINT(x) (((x) & (RAIL_TYPE_WAYPOINT|RAIL_WAYPOINT_UNUSED_BITS)) == RAIL_TYPE_WAYPOINT)

    47

    48

/* Format of rail map5 byte.

    49

 * 00 abcdef  => Normal rail

    50

 * 01 abcdef  => Rail with signals

    51

 * 10 ??????  => Unused

    52

 * 11 ????dd  => Depot

    53

 *

    54

 * abcdef is a bitmask, which contains ones for all present tracks. Below the

    55

 * value for each track is given.

    56

 */

    57

    58

/*         4

    59

 *     ---------

    60

 *    |\       /|

    61

 *    | \    1/ |

    62

 *    |  \   /  |

    63

 *    |   \ /   |

    64

 *  16|    \    |32

    65

 *    |   / \2  |

    66

 *    |  /   \  |

    67

 *    | /     \ |

    68

 *    |/       \|

    69

 *     ---------

    70

 *         8

    71

 */

    72

    73

    74

// Constants for lower part of Map2 byte.

    75

enum RailMap2Lower4 {

    76

	RAIL_MAP2LO_GROUND_MASK = 0xF,

    77

	RAIL_GROUND_BROWN = 0,

    78

	RAIL_GROUND_GREEN = 1,

    79

	RAIL_GROUND_FENCE_NW = 2,

    80

	RAIL_GROUND_FENCE_SE = 3,

    81

	RAIL_GROUND_FENCE_SENW = 4,

    82

	RAIL_GROUND_FENCE_NE = 5,

    83

	RAIL_GROUND_FENCE_SW = 6,

    84

	RAIL_GROUND_FENCE_NESW = 7,

    85

	RAIL_GROUND_FENCE_VERT1 = 8,

    86

	RAIL_GROUND_FENCE_VERT2 = 9,

    87

	RAIL_GROUND_FENCE_HORIZ1 = 10,

    88

	RAIL_GROUND_FENCE_HORIZ2 = 11,

    89

	RAIL_GROUND_ICE_DESERT = 12,

    90

};

    91

    92

    93

/* MAP2 byte:    abcd???? => Signal On? Same coding as map3lo

    94

 * MAP3LO byte:  abcd???? => Signal Exists?

    95

 *				 a and b are for diagonals, upper and left,

    96

 *				 one for each direction. (ie a == NE->SW, b ==

    97

 *				 SW->NE, or v.v., I don't know. b and c are

    98

 *				 similar for lower and right.

    99

 * MAP2 byte:    ????abcd => Type of ground.

   100

 * MAP3LO byte:  ????abcd => Type of rail.

   101

 * MAP5:         00abcdef => rail

   102

 *               01abcdef => rail w/ signals

   103

 *               10uuuuuu => unused

   104

 *               11uuuudd => rail depot

   105

 */

   106

   107

static bool CheckTrackCombination(byte map5, byte trackbits, byte flags)

   108

{

   109

	_error_message = STR_1001_IMPOSSIBLE_TRACK_COMBINATION;

   110

   111

	if ((map5&RAIL_TYPE_MASK) == RAIL_TYPE_SIGNALS) {

   112

   113

		if (map5 & trackbits) {

   114

			_error_message = STR_1007_ALREADY_BUILT;

   115

			return false;

   116

		}

   117

   118

		map5 |= trackbits;

   119

		return (map5 == (RAIL_TYPE_SIGNALS|RAIL_BIT_UPPER|RAIL_BIT_LOWER) || map5 == (RAIL_TYPE_SIGNALS|RAIL_BIT_LEFT|RAIL_BIT_RIGHT));

   120

   121

	} else if ((map5&RAIL_TYPE_MASK) == RAIL_TYPE_NORMAL) {

   122

		_error_message = STR_1007_ALREADY_BUILT;

   123

		if (map5 & trackbits)

   124

			return false;

   125

   126

		// Computer players are not allowed to intersect pieces of rail.

   127

		if (!(flags&DC_NO_RAIL_OVERLAP))

   128

			return true;

   129

   130

		map5 |= trackbits;

   131

		return (map5 == (RAIL_BIT_UPPER|RAIL_BIT_LOWER) || map5 == (RAIL_BIT_LEFT|RAIL_BIT_RIGHT));

   132

	} else {

   133

		return false;

   134

	}

   135

}

   136

   137

   138

static const byte _valid_tileh_slopes[4][15] = {

   139

   140

// set of normal ones

   141

{

   142

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   143

	RAIL_BIT_RIGHT,

   144

	RAIL_BIT_UPPER,

   145

	RAIL_BIT_DIAG1,

   146

   147

	RAIL_BIT_LEFT,

   148

	0,

   149

	RAIL_BIT_DIAG2,

   150

	RAIL_BIT_LOWER,

   151

   152

	RAIL_BIT_LOWER,

   153

	RAIL_BIT_DIAG2,

   154

	0,

   155

	RAIL_BIT_LEFT,

   156

   157

	RAIL_BIT_DIAG1,

   158

	RAIL_BIT_UPPER,

   159

	RAIL_BIT_RIGHT,

   160

},

   161

   162

// allowed rail for an evenly raised platform

   163

{

   164

	0,

   165

	RAIL_BIT_LEFT,

   166

	RAIL_BIT_LOWER,

   167

	RAIL_BIT_DIAG2 | RAIL_BIT_LOWER | RAIL_BIT_LEFT,

   168

   169

	RAIL_BIT_RIGHT,

   170

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   171

	RAIL_BIT_DIAG1 | RAIL_BIT_LOWER | RAIL_BIT_RIGHT,

   172

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   173

   174

	RAIL_BIT_UPPER,

   175

	RAIL_BIT_DIAG1 | RAIL_BIT_UPPER | RAIL_BIT_LEFT,

   176

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   177

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   178

   179

	RAIL_BIT_DIAG2 | RAIL_BIT_UPPER | RAIL_BIT_RIGHT,

   180

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   181

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   182

},

   183

   184

// allowed rail on coast tile

   185

{

   186

	0,

   187

	RAIL_BIT_LEFT,

   188

	RAIL_BIT_LOWER,

   189

	RAIL_BIT_DIAG2|RAIL_BIT_LEFT|RAIL_BIT_LOWER,

   190

   191

	RAIL_BIT_RIGHT,

   192

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   193

	RAIL_BIT_DIAG1|RAIL_BIT_RIGHT|RAIL_BIT_LOWER,

   194

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   195

   196

	RAIL_BIT_UPPER,

   197

	RAIL_BIT_DIAG1|RAIL_BIT_LEFT|RAIL_BIT_UPPER,

   198

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   199

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   200

   201

	RAIL_BIT_DIAG2|RAIL_BIT_RIGHT|RAIL_BIT_UPPER,

   202

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   203

	RAIL_BIT_DIAG1|RAIL_BIT_DIAG2|RAIL_BIT_UPPER|RAIL_BIT_LOWER|RAIL_BIT_LEFT|RAIL_BIT_RIGHT,

   204

	},

   205

   206

	// valid railway crossings on slopes

   207

	{

   208

		1, 0, 0, // 0, 1, 2

   209

		0, 0, 1, // 3, 4, 5

   210

		0, 1, 0, // 6, 7, 8

   211

		0, 1, 1, // 9, 10, 11

   212

		0, 1, 1, // 12, 13, 14

   213

	}

   214

};

   215

   216

uint GetRailFoundation(uint tileh, uint bits)

   217

{

   218

	int i;

   219

   220

	if ((~_valid_tileh_slopes[0][tileh] & bits) == 0)

   221

		return 0;

   222

   223

	if ((~_valid_tileh_slopes[1][tileh] & bits) == 0)

   224

		return tileh;

   225

   226

	if ( ((i=0, tileh == 1) || (i+=2, tileh == 2) || (i+=2, tileh == 4) || (i+=2, tileh == 8)) && (bits == RAIL_BIT_DIAG1 || (i++, bits == RAIL_BIT_DIAG2)))

   227

		return i + 15;

   228

   229

	return 0;

   230

}

   231

   232

//

   233

static uint32 CheckRailSlope(int tileh, uint rail_bits, uint existing, uint tile)

   234

{

   235

	// never allow building on top of steep tiles

   236

	if (!(tileh & 0x10)) {

   237

		rail_bits |= existing;

   238

   239

		// don't allow building on the lower side of a coast

   240

		if (IsTileType(tile, MP_WATER) && ~_valid_tileh_slopes[2][tileh] & rail_bits) {

   241

			return_cmd_error(STR_3807_CAN_T_BUILD_ON_WATER);

   242

		}

   243

   244

		// no special foundation

   245

		if ((~_valid_tileh_slopes[0][tileh] & rail_bits) == 0)

   246

			return 0;

   247

   248

		if (((~_valid_tileh_slopes[1][tileh] & rail_bits) == 0) || // whole tile is leveled up

   249

			((rail_bits == RAIL_BIT_DIAG1 || rail_bits == RAIL_BIT_DIAG2) && (tileh == 1 || tileh == 2 || tileh == 4 || tileh == 8))) { // partly up

   250

			return existing ? 0 : _price.terraform;

   251

		}

   252

	}

   253

	return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);

   254

}

   255

   256

/* Build a single track.

   257

 * p1 - railroad type normal/maglev

   258

 * p2 - tile direction

   259

 */

   260

   261

int32 CmdBuildSingleRail(int x, int y, uint32 flags, uint32 p1, uint32 p2)

   262

{

   263

	TileInfo ti;

   264

	int32 ret, cost = 0;

   265

	byte rail_bit = 1 << p2;

   266

	byte rail_type = (byte)(p1 & 0xF);

   267

	uint tile;

   268

	byte existing = 0;

   269

	bool need_clear = false;

   270

   271

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

   272

   273

	_error_message = STR_1007_ALREADY_BUILT;

   274

   275

	FindLandscapeHeight(&ti, x, y);

   276

	tile = ti.tile;

   277

   278

	// allow building rail under bridge

   279

	if (ti.type != MP_TUNNELBRIDGE && !EnsureNoVehicle(tile))

   280

		return CMD_ERROR;

   281

   282

	if (ti.type == MP_TUNNELBRIDGE) {

   283

/* BUILD ON BRIDGE CODE */

   284

		if (!EnsureNoVehicleZ(tile, TilePixelHeight(tile)))

   285

			return CMD_ERROR;

   286

   287

		if ((ti.map5 & 0xF8) == 0xC0) {

   288

			if (ti.tileh & 0x10 || rail_bit != (byte)((ti.map5 & 1) ? 1 : 2)) goto need_clear;

   289

   290

			if (!(flags & DC_EXEC))

   291

				return _price.build_rail;

   292

   293

			_map5[tile] = (ti.map5 & 0xC7) | 0x20;

   294

			goto set_ownership;

   295

		} else if ((ti.map5 & 0xF8) == 0xE0) {

   296

			if ((_map3_lo[tile] & 0xF) != (int)p1) goto need_clear;

   297

			if (rail_bit != (byte)((ti.map5 & 1) ? 1 : 2)) goto need_clear;

   298

			return CMD_ERROR;

   299

		} else

   300

			goto need_clear;

   301

	} else if (ti.type == MP_STREET) {

   302

		byte m5;

   303

/* BUILD ON STREET CODE */

   304

		if (ti.tileh & 0x10) // very steep tile

   305

				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);

   306

   307

		if (!_valid_tileh_slopes[3][ti.tileh]) // prevent certain slopes

   308

				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);

   309

   310

		if (!(ti.map5 & 0xF0)) {

   311

			if ((ti.map5 & 0x0F) == 0xA) {

   312

				if (rail_bit != 2) goto need_clear;

   313

				m5 = 0x10;

   314

			} else if ((ti.map5 & 0x0F) == 0x5) {

   315

				if (rail_bit != 1) goto need_clear;

   316

				m5 = 0x18;

   317

			} else

   318

				goto need_clear;

   319

   320

			if (!(flags & DC_EXEC))

   321

				return _price.build_rail;

   322

   323

			ModifyTile(tile,

   324

				MP_SETTYPE(MP_STREET) |

   325

				MP_MAP3LO | MP_MAP3HI | MP_MAPOWNER_CURRENT | MP_MAP5,

   326

				_map_owner[tile], /* map3_lo */

   327

				p1, /* map3_hi */

   328

				m5  /* map5 */

   329

			);

   330

			goto fix_signals;

   331

		} else if (!(ti.map5 & 0xE0)) {

   332

			if (rail_bit != (byte)((ti.map5 & 8) ? 1 : 2)) goto need_clear;

   333

			return CMD_ERROR;

   334

		} else

   335

			goto need_clear;

   336

	} else if (ti.type == MP_RAILWAY) {

   337

   338

/* BUILD ON RAILWAY CODE */

   339

		if (_map_owner[tile] != _current_player || (byte)(_map3_lo[tile]&0xF) != rail_type)

   340

			goto need_clear;

   341

		if (!CheckTrackCombination(ti.map5, rail_bit, (byte)flags))

   342

			return CMD_ERROR;

   343

   344

		existing = ti.map5 & 0x3F;

   345

	} else {

   346

   347

/* DEFAULT BUILD ON CODE */

   348

need_clear:;

   349

		/* isnot_railway */

   350

		if (!(flags & DC_EXEC)) {

   351

			ret = DoCommandByTile(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);

   352

			if (ret == CMD_ERROR) return CMD_ERROR;

   353

			cost += ret;

   354

		}

   355

		need_clear = true;

   356

	}

   357

   358

	ret = CheckRailSlope(ti.tileh, rail_bit, existing, tile);

   359

	if (ret & 0x80000000)

   360

		return ret;

   361

	cost += ret;

   362

   363

	// the AI is not allowed to used foundationed tiles.

   364

	if (ret && (!_patches.build_on_slopes || (!_patches.ainew_active && _is_ai_player)))

   365

		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);

   366

   367

	if (flags & DC_EXEC && need_clear) {

   368

		ret = DoCommandByTile(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);

   369

		if (ret == CMD_ERROR) return CMD_ERROR;

   370

		cost += ret;

   371

	}

   372

   373

	if (flags & DC_EXEC) {

   374

		SetTileType(tile, MP_RAILWAY);

   375

		_map5[tile] |= rail_bit;

   376

		_map2[tile] &= ~RAIL_MAP2LO_GROUND_MASK;

   377

   378

		// In case it's a tile without signals, clear the signal bits. Why?

   379

		if ((_map5[tile] & RAIL_TYPE_MASK) != RAIL_TYPE_SIGNALS)

   380

			_map2[tile] &= ~0xF0;

   381

   382

set_ownership:

   383

		_map_owner[tile] = _current_player;

   384

   385

		_map3_lo[tile] &= ~0xF;

   386

		_map3_lo[tile] |= rail_type;

   387

   388

		MarkTileDirtyByTile(tile);

   389

   390

fix_signals:

   391

		SetSignalsOnBothDir(tile, (byte)p2);

   392

	}

   393

   394

	return cost + _price.build_rail;

   395

}

   396

   397

static const byte _signals_table[] = {

   398

	0x40, 0x40, 0x40, 0x10, 0x80, 0x20, 0, 0, // direction 1

   399

	0x80, 0x80, 0x80, 0x20, 0x40, 0x10, 0, 0  // direction 2

   400

};

   401

   402

static const byte _signals_table_other[] = {

   403

	0x80, 0x80, 0x80, 0x20, 0x40, 0x10, 0, 0, // direction 1

   404

	0x40, 0x40, 0x40, 0x10, 0x80, 0x20, 0, 0  // direction 2

   405

};

   406

   407

static const byte _signals_table_both[] = {

   408

	0xC0, 0xC0, 0xC0, 0x30, 0xC0, 0x30, 0, 0,	// both directions combined

   409

	0xC0, 0xC0, 0xC0, 0x30, 0xC0, 0x30, 0, 0

   410

};

   411

   412

   413

/* Remove a single track.

   414

 * p1 - unused

   415

 * p2 - tile direction

   416

 */

   417

   418

int32 CmdRemoveSingleRail(int x, int y, uint32 flags, uint32 p1, uint32 p2)

   419

{

   420

	TileInfo ti;

   421

	byte rail_bit = 1 << p2;

   422

	byte m5;

   423

	uint tile;

   424

   425

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

   426

   427

	FindLandscapeHeight(&ti, x, y);

   428

   429

	tile = ti.tile;

   430

   431

	if (!((1<<ti.type) & ((1<<MP_TUNNELBRIDGE)|(1<<MP_STREET)|(1<<MP_RAILWAY))))

   432

		return CMD_ERROR;

   433

   434

	if (_current_player != OWNER_WATER && !CheckTileOwnership(tile))

   435

		return CMD_ERROR;

   436

   437

	// allow building rail under bridge

   438

	if (ti.type != MP_TUNNELBRIDGE && !EnsureNoVehicle(tile))

   439

		return CMD_ERROR;

   440

   441

	if (ti.type == MP_TUNNELBRIDGE) {

   442

		if (!EnsureNoVehicleZ(tile, TilePixelHeight(tile)))

   443

			return CMD_ERROR;

   444

   445

		if ((ti.map5 & 0xF8) != 0xE0)

   446

			return CMD_ERROR;

   447

   448

		if ( ((ti.map5 & 1) ? 1 : 2) != rail_bit )

   449

			return CMD_ERROR;

   450

   451

		if (!(flags & DC_EXEC))

   452

			return _price.remove_rail;

   453

   454

		_map_owner[tile] = OWNER_NONE;

   455

		_map5[tile] = ti.map5 & 0xC7;

   456

	} else if (ti.type == MP_STREET) {

   457

		if (!(ti.map5 & 0xF0))

   458

			return CMD_ERROR;

   459

   460

		if (ti.map5 & 0xE0)

   461

			return CMD_ERROR;

   462

   463

		if (ti.map5 & 8) {

   464

			m5 = 5;

   465

			if (rail_bit != 1)

   466

				return CMD_ERROR;

   467

		} else {

   468

			m5 = 10;

   469

			if (rail_bit != 2)

   470

				return CMD_ERROR;

   471

		}

   472

   473

		if (!(flags & DC_EXEC))

   474

			return _price.remove_rail;

   475

   476

		_map5[tile] = m5;

   477

		_map_owner[tile] = _map3_lo[tile];

   478

		_map2[tile] = 0;

   479

	} else {

   480

		assert(ti.type == MP_RAILWAY);

   481

   482

		if (ti.map5 & RAIL_TYPE_SPECIAL)

   483

			return CMD_ERROR;

   484

   485

		if (!(ti.map5 & rail_bit))

   486

			return CMD_ERROR;

   487

   488

		// don't allow remove if there are signals on the track

   489

		if (ti.map5 & RAIL_TYPE_SIGNALS) {

   490

			if (_map3_lo[tile] & _signals_table_both[p2])

   491

				return CMD_ERROR;

   492

		}

   493

   494

		if (!(flags & DC_EXEC))

   495

			return _price.remove_rail;

   496

   497

		if ( (_map5[tile] ^= rail_bit) == 0) {

   498

			DoClearSquare(tile);

   499

			goto skip_mark_dirty;

   500

		}

   501

	}

   502

   503

	/* mark_dirty */

   504

	MarkTileDirtyByTile(tile);

   505

   506

skip_mark_dirty:;

   507

   508

	SetSignalsOnBothDir(tile, (byte)p2);

   509

   510

	return _price.remove_rail;

   511

}

   512

   513

static const struct {

   514

	int8 xinc[16];

   515

	int8 yinc[16];

   516

} _railbit = {{

   517

//  0   1   2   3   4   5

   518

	-16,  0,-16,  0, 16,  0,    0,  0,

   519

	 16,  0,  0, 16,  0,-16,    0,  0,