summaryrefslogtreecommitdiff
path: root/rail.h
blob: db25c0528dbae9c181ee3d28158f48f0a4579f7d (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
/* $Id$ */

/** @file rail.h */

#ifndef RAIL_H
#define RAIL_H

#include "direction.h"
#include "rail_map.h"
#include "tile.h"

/** 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_X_NE = 0,
	TRACKDIR_Y_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_X_SW = 8,
	TRACKDIR_Y_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_X_NE     = 0x1,
	TRACKDIR_BIT_Y_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_X_SW     = 0x0100,
	TRACKDIR_BIT_Y_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;

/** 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 {
		CursorID rail_ns;
		CursorID rail_swne;
		CursorID rail_ew;
		CursorID rail_nwse;
		CursorID autorail;
		CursorID depot;
		CursorID tunnel;
		CursorID convert;
	} cursor;

	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 on which an engine of THIS railtype generates power */
	RailTypeMask powered_railtypes;

	/** bitmask to the OTHER railtypes on which an engine of THIS railtype can physically travel */
	RailTypeMask 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;

	/**
	  * Bridge offset
	  */
	SpriteID bridge_offset;

	/**
	 * Offset to add to ground sprite when drawing custom waypoints / stations
	 */
	byte custom_ground_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];
}


/*
 * 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) {
	return (Trackdir)(trackdir ^ 8);
}

/**
 * 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));}

/**
 * Discards all directional information from the given TrackdirBits. Any
 * Track which is present in either direction will be present in the result.
 */
static inline TrackBits TrackdirBitsToTrackBits(TrackdirBits bits) { return bits | (bits >> 8); }

/**
 * 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];
}

extern const TrackdirBits _exitdir_reaches_trackdirs[DIAGDIR_END];

/**
 * Returns all trackdirs that can be reached when entering a tile from a given
 * (diagonal) direction. This will obviously include 90 degree turns, since no
 * information is available about the exact angle of entering */
static inline TrackdirBits DiagdirReachesTrackdirs(DiagDirection diagdir) { return _exitdir_reaches_trackdirs[diagdir]; }

/**
 * Returns all tracks that can be reached when entering a tile from a given
 * (diagonal) direction. This will obviously include 90 degree turns, since no
 * information is available about the exact angle of entering */
static inline TrackBits DiagdirReachesTracks(DiagDirection diagdir) { return TrackdirBitsToTrackBits(DiagdirReachesTrackdirs(diagdir)); }

/**
 * Maps a trackdir to the trackdirs that can be reached from it (ie, when
 * entering the next tile. This will include 90 degree turns!
 */
static inline TrackdirBits TrackdirReachesTrackdirs(Trackdir trackdir) { return _exitdir_reaches_trackdirs[TrackdirToExitdir(trackdir)]; }
/* Note that there is no direct table for this function (there used to be),
 * but it uses two simpeler tables to achieve the result */


/**
 * 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)];
}


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

/* 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 GetSignalStateByTrackdir(TileIndex tile, Trackdir trackdir)
{
	assert(IsValidTrackdir(trackdir));
	assert(HasSignalOnTrack(tile, TrackdirToTrack(trackdir)));
	return _m[tile].m2 & SignalAlongTrackdir(trackdir) ?
		SIGNAL_STATE_GREEN : SIGNAL_STATE_RED;
}


/**
 * 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 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);
}

static inline bool HasPowerOnRail(RailType enginetype, RailType tiletype)
{
	return HASBIT(GetRailTypeInfo(enginetype)->powered_railtypes, tiletype);
}

/**
 * Checks if the given tracks overlap, ie form a crossing. Basically this
 * means when there is more than one track on the tile, exept when there are
 * two parallel tracks.
 * @param  bits The tracks present.
 * @return Whether the tracks present overlap in any way.
 */
static inline bool TracksOverlap(TrackBits bits)
{
  /* With no, or only one track, there is no overlap */
  if (bits == 0 || KILL_FIRST_BIT(bits) == 0) return false;
  /* We know that there are at least two tracks present. When there are more
   * than 2 tracks, they will surely overlap. When there are two, they will
   * always overlap unless they are lower & upper or right & left. */
	return bits != TRACK_BIT_HORZ && bits != TRACK_BIT_VERT;
}

void DrawTrainDepotSprite(int x, int y, int image, RailType railtype);
void DrawDefaultWaypointSprite(int x, int y, RailType railtype);

/**
 * Draws overhead wires and pylons for electric railways.
 * @param ti The TileInfo struct of the tile being drawn
 * @see DrawCatenaryRailway
 */
void DrawCatenary(const TileInfo *ti);

uint GetRailFoundation(Slope tileh, TrackBits bits);
#endif /* RAIL_H */