summaryrefslogtreecommitdiff
path: root/rail.h
blob: 215a291dd7cc17e650d27126b68299953e367dd2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
/* $Id$ */

/** @file rail.h */

#ifndef RAIL_H
#define RAIL_H

#include "tile.h"

/*
 * Some enums for accesing the map bytes for rail tiles
 */

/** These types are used in the map5 byte for rail tiles. Use GetRailTileType() to
 * get these values */
typedef enum RailTileTypes {
	RAIL_TYPE_NORMAL         = 0x0,
	RAIL_TYPE_SIGNALS        = 0x40,
	RAIL_TYPE_UNUSED         = 0x80, /* XXX: Maybe this could become waypoints? */
	RAIL_TYPE_DEPOT_WAYPOINT = 0xC0, /* Is really depots and waypoints... */
	RAIL_TILE_TYPE_MASK      = 0xC0,
} RailTileType;

enum { /* DEPRECATED TODO: Rewrite all uses of this */
	RAIL_TYPE_SPECIAL = 0x80, /* This used to say "If this bit is set, then it's
														 * not a regular track.", but currently, you
														 * should rather view map5[6..7] as one type,
														 * containing a value from RailTileTypes above.
														 * This value is only maintained for backwards
														 * compatibility */

	/* There used to be RAIL_BIT_* enums here, they moved to (for now) npf.c as
	 * TRACK_BIT_* */
};

/** These subtypes are used in the map5 byte when the main rail type is
 * RAIL_TYPE_DEPOT_WAYPOINT */
typedef enum RailTileSubtypes {
	RAIL_SUBTYPE_DEPOT    = 0x00,
	RAIL_SUBTYPE_WAYPOINT = 0x04,
	RAIL_SUBTYPE_MASK     = 0x3C,
} RailTileSubtype;

typedef enum SignalTypes {
	/* Stored in m4[0..1] for MP_RAILWAY */
  SIGTYPE_NORMAL  = 0,        // normal signal
  SIGTYPE_ENTRY   = 1,        // presignal block entry
  SIGTYPE_EXIT    = 2,        // presignal block exit
  SIGTYPE_COMBO   = 3,        // presignal inter-block
	SIGTYPE_PBS     = 4,        // pbs signal
	SIGTYPE_END,
	SIGTYPE_MASK    = 7,
} SignalType;

typedef enum RailTypes {
	RAILTYPE_RAIL   = 0,
	RAILTYPE_MONO   = 1,
	RAILTYPE_MAGLEV = 2,
	RAILTYPE_END,
	RAILTYPE_MASK   = 0x3,
	INVALID_RAILTYPE = 0xFF,
} RailType;

enum {
	SIG_SEMAPHORE_MASK = 1 << 3,
};

/** These are used to specify a single track. Can be translated to a trackbit
 * with TrackToTrackbit */
typedef enum Tracks {
  TRACK_DIAG1 = 0,
  TRACK_DIAG2 = 1,
  TRACK_UPPER = 2,
  TRACK_LOWER = 3,
  TRACK_LEFT  = 4,
  TRACK_RIGHT = 5,
  TRACK_END,
  INVALID_TRACK = 0xFF,
} Track;

/** These are the bitfield variants of the above */
typedef enum TrackBits {
  TRACK_BIT_DIAG1 = 1,  // 0
  TRACK_BIT_DIAG2 = 2,  // 1
  TRACK_BIT_UPPER = 4,  // 2
  TRACK_BIT_LOWER = 8,  // 3
  TRACK_BIT_LEFT  = 16, // 4
  TRACK_BIT_RIGHT = 32, // 5
	TRACK_BIT_MASK  = 0x3F,
} TrackBits;

/** These are a combination of tracks and directions. Values are 0-5 in one
direction (corresponding to the Track enum) and 8-13 in the other direction. */
typedef enum Trackdirs {
  TRACKDIR_DIAG1_NE = 0,
  TRACKDIR_DIAG2_SE = 1,
  TRACKDIR_UPPER_E  = 2,
  TRACKDIR_LOWER_E  = 3,
  TRACKDIR_LEFT_S   = 4,
  TRACKDIR_RIGHT_S  = 5,
	/* Note the two missing values here. This enables trackdir -> track
	 * conversion by doing (trackdir & 7) */
  TRACKDIR_DIAG1_SW = 8,
  TRACKDIR_DIAG2_NW = 9,
  TRACKDIR_UPPER_W  = 10,
  TRACKDIR_LOWER_W  = 11,
  TRACKDIR_LEFT_N   = 12,
  TRACKDIR_RIGHT_N  = 13,
  TRACKDIR_END,
  INVALID_TRACKDIR  = 0xFF,
} Trackdir;

/** These are a combination of tracks and directions. Values are 0-5 in one
direction (corresponding to the Track enum) and 8-13 in the other direction. */
typedef enum TrackdirBits {
  TRACKDIR_BIT_DIAG1_NE = 0x1,
  TRACKDIR_BIT_DIAG2_SE = 0x2,
  TRACKDIR_BIT_UPPER_E  = 0x4,
  TRACKDIR_BIT_LOWER_E  = 0x8,
  TRACKDIR_BIT_LEFT_S   = 0x10,
  TRACKDIR_BIT_RIGHT_S  = 0x20,
	/* Again, note the two missing values here. This enables trackdir -> track conversion by doing (trackdir & 0xFF) */
  TRACKDIR_BIT_DIAG1_SW = 0x0100,
  TRACKDIR_BIT_DIAG2_NW = 0x0200,
  TRACKDIR_BIT_UPPER_W  = 0x0400,
  TRACKDIR_BIT_LOWER_W  = 0x0800,
  TRACKDIR_BIT_LEFT_N   = 0x1000,
  TRACKDIR_BIT_RIGHT_N  = 0x2000,
	TRACKDIR_BIT_MASK			= 0x3F3F,
  INVALID_TRACKDIR_BIT  = 0xFFFF,
} TrackdirBits;

/** These are states in which a signal can be. Currently these are only two, so
 * simple boolean logic will do. But do try to compare to this enum instead of
 * normal boolean evaluation, since that will make future additions easier.
 */
typedef enum SignalStates {
	SIGNAL_STATE_RED = 0,
	SIGNAL_STATE_GREEN = 1,
} SignalState;

/** This struct contains all the info that is needed to draw and construct tracks.
 */
typedef struct RailtypeInfo {
	/** Struct containing the main sprites. @note not all sprites are listed, but only
	 *  the ones used directly in the code */
	struct {
		SpriteID track_y;      ///< single piece of rail in Y direction, with ground
		SpriteID track_ns;     ///< two pieces of rail in North and South corner (East-West direction)
		SpriteID ground;       ///< ground sprite for a 3-way switch
		SpriteID single_y;     ///< single piece of rail in Y direction, without ground
		SpriteID single_x;     ///< single piece of rail in X direction
		SpriteID single_n;     ///< single piece of rail in the northern corner
		SpriteID single_s;     ///< single piece of rail in the southern corner
		SpriteID single_e;     ///< single piece of rail in the eastern corner
		SpriteID single_w;     ///< single piece of rail in the western corner
		SpriteID crossing;     ///< level crossing, rail in X direction
		SpriteID tunnel;       ///< tunnel sprites base
	} base_sprites;

	/** struct containing the sprites for the rail GUI. @note only sprites referred to
	 * directly in the code are listed */
	struct {
		SpriteID build_ns_rail;      ///< button for building single rail in N-S direction
		SpriteID build_x_rail;       ///< button for building single rail in X direction
		SpriteID build_ew_rail;      ///< button for building single rail in E-W direction
		SpriteID build_y_rail;       ///< button for building single rail in Y direction
		SpriteID auto_rail;          ///< button for the autorail construction
		SpriteID build_depot;        ///< button for building depots
		SpriteID build_tunnel;       ///< button for building a tunnel
		SpriteID convert_rail;       ///< button for converting rail
	} gui_sprites;

	struct {
		StringID toolbar_caption;
	} strings;

	/** sprite number difference between a piece of track on a snowy ground and the corresponding one on normal ground */
	SpriteID snow_offset;

	/** bitmask to the OTHER railtypes that can be used by an engine of THIS railtype */
	byte compatible_railtypes;

	/**
	 * Offset between the current railtype and normal rail. This means that:<p>
	 * 1) All the sprites in a railset MUST be in the same order. This order
	 *    is determined by normal rail. Check sprites 1005 and following for this order<p>
	 * 2) The position where the railtype is loaded must always be the same, otherwise
	 *    the offset will fail.<p>
	 * @note: Something more flexible might be desirable in the future.
	 */
	SpriteID total_offset;
} RailtypeInfo;

extern const RailtypeInfo _railtypes[RAILTYPE_END];

// these are the maximums used for updating signal blocks, and checking if a depot is in a pbs block
enum {
	NUM_SSD_ENTRY = 256, // max amount of blocks
	NUM_SSD_STACK = 32 ,// max amount of blocks to check recursively
};

/**
 * Maps a Trackdir to the corresponding TrackdirBits value
 */
static inline TrackdirBits TrackdirToTrackdirBits(Trackdir trackdir) { return (TrackdirBits)(1 << trackdir); }

/**
 * These functions check the validity of Tracks and Trackdirs. assert against
 * them when convenient.
 */
static inline bool IsValidTrack(Track track) { return track < TRACK_END; }
static inline bool IsValidTrackdir(Trackdir trackdir) { return (TrackdirToTrackdirBits(trackdir) & TRACKDIR_BIT_MASK) != 0; }

/**
 * Functions to map tracks to the corresponding bits in the signal
 * presence/status bytes in the map. You should not use these directly, but
 * wrapper functions below instead. XXX: Which are these?
 */

/**
 * Maps a trackdir to the bit that stores its status in the map arrays, in the
 * direction along with the trackdir.
 */
extern const byte _signal_along_trackdir[TRACKDIR_END];
static inline byte SignalAlongTrackdir(Trackdir trackdir) {return _signal_along_trackdir[trackdir];}

/**
 * Maps a trackdir to the bit that stores its status in the map arrays, in the
 * direction against the trackdir.
 */
static inline byte SignalAgainstTrackdir(Trackdir trackdir) {
	extern const byte _signal_against_trackdir[TRACKDIR_END];
	return _signal_against_trackdir[trackdir];
}

/**
 * Maps a Track to the bits that store the status of the two signals that can
 * be present on the given track.
 */
static inline byte SignalOnTrack(Track track) {
	extern const byte _signal_on_track[TRACK_END];
	return _signal_on_track[track];
}

/*
 * Some functions to query rail tiles
 */

/**
 * Returns the RailTileType of a given rail tile. (ie normal, with signals,
 * depot, etc.)
 */
static inline RailTileType GetRailTileType(TileIndex tile)
{
	assert(IsTileType(tile, MP_RAILWAY));
	return (_m[tile].m5 & RAIL_TILE_TYPE_MASK);
}

/**
 * Returns the rail type of the given rail tile (ie rail, mono, maglev).
 */
static inline RailType GetRailType(TileIndex tile) { return (RailType)(_m[tile].m3 & RAILTYPE_MASK); }

/**
 * Checks if a rail tile has signals.
 */
static inline bool HasSignals(TileIndex tile)
{
	return GetRailTileType(tile) == RAIL_TYPE_SIGNALS;
}

/**
 * Returns the RailTileSubtype of a given rail tile with type
 * RAIL_TYPE_DEPOT_WAYPOINT
 */
static inline RailTileSubtype GetRailTileSubtype(TileIndex tile)
{
	assert(GetRailTileType(tile) == RAIL_TYPE_DEPOT_WAYPOINT);
	return (RailTileSubtype)(_m[tile].m5 & RAIL_SUBTYPE_MASK);
}

/**
 * Returns whether this is plain rails, with or without signals. Iow, if this
 * tiles RailTileType is RAIL_TYPE_NORMAL or RAIL_TYPE_SIGNALS.
 */
static inline bool IsPlainRailTile(TileIndex tile)
{
	RailTileType rtt = GetRailTileType(tile);
	return rtt == RAIL_TYPE_NORMAL || rtt == RAIL_TYPE_SIGNALS;
}

/**
 * Returns the tracks present on the given plain rail tile (IsPlainRailTile())
 */
static inline TrackBits GetTrackBits(TileIndex tile)
{
	assert(GetRailTileType(tile) == RAIL_TYPE_NORMAL || GetRailTileType(tile) == RAIL_TYPE_SIGNALS);
	return (TrackBits)(_m[tile].m5 & TRACK_BIT_MASK);
}

/**
 * Returns whether the given track is present on the given tile. Tile must be
 * a plain rail tile (IsPlainRailTile()).
 */
static inline bool HasTrack(TileIndex tile, Track track)
{
	assert(IsValidTrack(track));
	return HASBIT(GetTrackBits(tile), track);
}

/*
 * Functions describing logical relations between Tracks, TrackBits, Trackdirs
 * TrackdirBits, Direction and DiagDirections.
 *
 * TODO: Add #unndefs or something similar to remove the arrays used below
 * from the global scope and expose direct uses of them.
 */

/**
 * Maps a trackdir to the reverse trackdir.
 */
static inline Trackdir ReverseTrackdir(Trackdir trackdir) {
	extern const Trackdir _reverse_trackdir[TRACKDIR_END];
	return _reverse_trackdir[trackdir];
}

/*
 * Maps a Track to the corresponding TrackBits value
 */
static inline TrackBits TrackToTrackBits(Track track) { return (TrackBits)(1 << track); }

/* Returns the Track that a given Trackdir represents */
static inline Track TrackdirToTrack(Trackdir trackdir) { return (Track)(trackdir & 0x7); }

/* Returns a Trackdir for the given Track. Since every Track corresponds to
 * two Trackdirs, we choose the one which points between NE and S.
 * Note that the actual implementation is quite futile, but this might change
 * in the future.
 */
static inline Trackdir TrackToTrackdir(Track track) { return (Trackdir)track; }

/* Returns a TrackdirBit mask that contains the two TrackdirBits that
 * correspond with the given Track (one for each direction).
 */
static inline TrackdirBits TrackToTrackdirBits(Track track) { Trackdir td = TrackToTrackdir(track); return TrackdirToTrackdirBits(td) | TrackdirToTrackdirBits(ReverseTrackdir(td));}

/**
 * Maps a trackdir to the trackdir that you will end up on if you go straight
 * ahead. This will be the same trackdir for diagonal trackdirs, but a
 * different (alternating) one for straight trackdirs
 */
static inline Trackdir NextTrackdir(Trackdir trackdir) {
	extern const Trackdir _next_trackdir[TRACKDIR_END];
	return _next_trackdir[trackdir];
}

/**
 * Maps a track to all tracks that make 90 deg turns with it.
 */
static inline TrackBits TrackCrossesTracks(Track track) {
	extern const TrackBits _track_crosses_tracks[TRACK_END];
	return _track_crosses_tracks[track];
}

/**
 * Maps a trackdir to the (4-way) direction the tile is exited when following
 * that trackdir.
 */
static inline DiagDirection TrackdirToExitdir(Trackdir trackdir) {
	extern const DiagDirection _trackdir_to_exitdir[TRACKDIR_END];
	return _trackdir_to_exitdir[trackdir];
}

/**
 * Maps a track and an (4-way) dir to the trackdir that represents the track
 * with the exit in the given direction.
 */
static inline Trackdir TrackExitdirToTrackdir(Track track, DiagDirection diagdir) {
	extern const Trackdir _track_exitdir_to_trackdir[TRACK_END][DIAGDIR_END];
	return _track_exitdir_to_trackdir[track][diagdir];
}

/**
 * Maps a track and an (4-way) dir to the trackdir that represents the track
 * with the exit in the given direction.
 */
static inline Trackdir TrackEnterdirToTrackdir(Track track, DiagDirection diagdir) {
	extern const Trackdir _track_enterdir_to_trackdir[TRACK_END][DIAGDIR_END];
	return _track_enterdir_to_trackdir[track][diagdir];
}

/**
 * Maps a track and a full (8-way) direction to the trackdir that represents
 * the track running in the given direction.
 */
static inline Trackdir TrackDirectionToTrackdir(Track track, Direction dir) {
	extern const Trackdir _track_direction_to_trackdir[TRACK_END][DIR_END];
	return _track_direction_to_trackdir[track][dir];
}

/**
 * Maps a (4-way) direction to the diagonal trackdir that runs in that
 * direction.
 */
static inline Trackdir DiagdirToDiagTrackdir(DiagDirection diagdir) {
	extern const Trackdir _dir_to_diag_trackdir[DIAGDIR_END];
	return _dir_to_diag_trackdir[diagdir];
}

/**
 * Maps a trackdir to the trackdirs that can be reached from it (ie, when
 * entering the next tile. This
 */
extern const TrackdirBits _exitdir_reaches_trackdirs[DIAGDIR_END];
/* Note that there is no direct table for this function (there used to be),
 * but it uses two simpeler tables to achieve the result */
static inline TrackdirBits TrackdirReachesTrackdirs(Trackdir trackdir) { return _exitdir_reaches_trackdirs[TrackdirToExitdir(trackdir)]; }

/**
 * Maps a trackdir to all trackdirs that make 90 deg turns with it.
 */
static inline TrackdirBits TrackdirCrossesTrackdirs(Trackdir trackdir) {
	extern const TrackdirBits _track_crosses_trackdirs[TRACKDIR_END];
	return _track_crosses_trackdirs[TrackdirToTrack(trackdir)];
}

/**
 * Maps a (4-way) direction to the reverse.
 */
static inline DiagDirection ReverseDiagdir(DiagDirection diagdir) {
	extern const DiagDirection _reverse_diagdir[DIAGDIR_END];
	return _reverse_diagdir[diagdir];
}

/**
 * Maps a (8-way) direction to a (4-way) DiagDirection
 */
static inline DiagDirection DirToDiagdir(Direction dir) {
	assert(dir < DIR_END);
	return (DiagDirection)(dir >> 1);
}

/* Checks if a given Track is diagonal */
static inline bool IsDiagonalTrack(Track track) { return (track == TRACK_DIAG1) || (track == TRACK_DIAG2); }

/* Checks if a given Trackdir is diagonal. */
static inline bool IsDiagonalTrackdir(Trackdir trackdir) { return IsDiagonalTrack(TrackdirToTrack(trackdir)); }

/*
 * Functions quering signals on tiles.
 */

/**
 * Checks for the presence of signals (either way) on the given track on the
 * given rail tile.
 */
static inline bool HasSignalOnTrack(TileIndex tile, Track track)
{
	assert(IsValidTrack(track));
	return ((GetRailTileType(tile) == RAIL_TYPE_SIGNALS) && ((_m[tile].m3 & SignalOnTrack(track)) != 0));
}

/**
 * Checks for the presence of signals along the given trackdir on the given
 * rail tile.
 *
 * Along meaning if you are currently driving on the given trackdir, this is
 * the signal that is facing us (for which we stop when it's red).
 */
static inline bool HasSignalOnTrackdir(TileIndex tile, Trackdir trackdir)
{
	assert (IsValidTrackdir(trackdir));
	return (GetRailTileType(tile) == RAIL_TYPE_SIGNALS) && (_m[tile].m3 & SignalAlongTrackdir(trackdir));
}

/**
 * Gets the state of the signal along the given trackdir.
 *
 * Along meaning if you are currently driving on the given trackdir, this is
 * the signal that is facing us (for which we stop when it's red).
 */
static inline SignalState GetSignalState(TileIndex tile, Trackdir trackdir)
{
	assert(IsValidTrackdir(trackdir));
	assert(HasSignalOnTrack(tile, TrackdirToTrack(trackdir)));
	return ((_m[tile].m2 & SignalAlongTrackdir(trackdir))?SIGNAL_STATE_GREEN:SIGNAL_STATE_RED);
}

/**
 * Gets the type of signal on a given track on a given rail tile with signals.
 *
 * Note that currently, the track argument is not used, since
 * signal types cannot be mixed. This function is trying to be
 * future-compatible, though.
 */
static inline SignalType GetSignalType(TileIndex tile, Track track)
{
	assert(IsValidTrack(track));
	assert(GetRailTileType(tile) == RAIL_TYPE_SIGNALS);
	return (SignalType)(_m[tile].m4 & SIGTYPE_MASK);
}

/**
 * Checks if this tile contains semaphores (returns true) or normal signals
 * (returns false) on the given track. Does not check if there are actually
 * signals on the track, you should use HasSignalsOnTrack() for that.
 *
 * Note that currently, the track argument is not used, since
 * semaphores/electric signals cannot be mixed. This function is trying to be
 * future-compatible, though.
 */
static inline bool HasSemaphores(TileIndex tile, Track track)
{
	assert(IsValidTrack(track));
	return (_m[tile].m4 & SIG_SEMAPHORE_MASK);
}

/**
 * Return the rail type of tile, or INVALID_RAILTYPE if this is no rail tile.
 * Note that there is no check if the given trackdir is actually present on
 * the tile!
 * The given trackdir is used when there are (could be) multiple rail types on
 * one tile.
 */
RailType GetTileRailType(TileIndex tile, Trackdir trackdir);

/**
 * Returns whether the given tile is a level crossing.
 */
static inline bool IsLevelCrossing(TileIndex tile)
{
	return (_m[tile].m5 & 0xF0) == 0x10;
}

/**
 * Gets the transport type of the given track on the given crossing tile.
 * @return  The transport type of the given track, either TRANSPORT_ROAD,
 * TRANSPORT_RAIL.
 */
static inline TransportType GetCrossingTransportType(TileIndex tile, Track track)
{
	/* XXX: Nicer way to write this? */
	switch(track)
	{
		/* When map5 bit 3 is set, the road runs in the y direction (DIAG2) */
		case TRACK_DIAG1:
			return (HASBIT(_m[tile].m5, 3) ? TRANSPORT_RAIL : TRANSPORT_ROAD);
		case TRACK_DIAG2:
			return (HASBIT(_m[tile].m5, 3) ? TRANSPORT_ROAD : TRANSPORT_RAIL);
		default:
			assert(0);
	}
	return INVALID_TRANSPORT;
}

/**
 * Returns a pointer to the Railtype information for a given railtype
 * @param railtype the rail type which the information is requested for
 * @return The pointer to the RailtypeInfo
 */
static inline const RailtypeInfo *GetRailTypeInfo(RailType railtype)
{
	assert(railtype < RAILTYPE_END);
	return &_railtypes[railtype];
}

/**
 * Checks if an engine of the given RailType can drive on a tile with a given
 * RailType. This would normally just be an equality check, but for electric
 * rails (which also support non-electric engines).
 * @return Whether the engine can drive on this tile.
 * @param  enginetype The RailType of the engine we are considering.
 * @param  tiletype   The RailType of the tile we are considering.
 */
static inline bool IsCompatibleRail(RailType enginetype, RailType tiletype)
{
	return HASBIT(GetRailTypeInfo(enginetype)->compatible_railtypes, tiletype);
}

void DrawTrackBits(TileInfo *ti, TrackBits track, bool earth, bool snow, bool flat);

#endif /* RAIL_H */