summaryrefslogtreecommitdiff
path: root/newgrf_engine.c
blob: 3b486a3ab07805ac4c0a3418122bc13d271f3d46 (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
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
/* $Id$ */

#include "stdafx.h"
#include "openttd.h"
#include "variables.h"
#include "debug.h"
#include "functions.h"
#include "engine.h"
#include "train.h"
#include "player.h"
#include "station.h"
#include "airport.h"
#include "newgrf_callbacks.h"
#include "newgrf_engine.h"
#include "newgrf_station.h"
#include "newgrf_spritegroup.h"

// TODO: We don't support cargo-specific wagon overrides. Pretty exotic... ;-) --pasky

typedef struct WagonOverride {
	byte *train_id;
	int trains;
	const SpriteGroup *group;
} WagonOverride;

typedef struct WagonOverrides {
	int overrides_count;
	WagonOverride *overrides;
} WagonOverrides;

static WagonOverrides _engine_wagon_overrides[TOTAL_NUM_ENGINES];

void SetWagonOverrideSprites(EngineID engine, const SpriteGroup *group, byte *train_id, int trains)
{
	WagonOverrides *wos;
	WagonOverride *wo;

	wos = &_engine_wagon_overrides[engine];
	wos->overrides_count++;
	wos->overrides = realloc(wos->overrides,
		wos->overrides_count * sizeof(*wos->overrides));

	wo = &wos->overrides[wos->overrides_count - 1];
	/* FIXME: If we are replacing an override, release original SpriteGroup
	 * to prevent leaks. But first we need to refcount the SpriteGroup.
	 * --pasky */
	wo->group = group;
	wo->trains = trains;
	wo->train_id = malloc(trains);
	memcpy(wo->train_id, train_id, trains);
}

static const SpriteGroup *GetWagonOverrideSpriteSet(EngineID engine, byte overriding_engine)
{
	const WagonOverrides *wos = &_engine_wagon_overrides[engine];
	int i;

	// XXX: This could turn out to be a timesink on profiles. We could
	// always just dedicate 65535 bytes for an [engine][train] trampoline
	// for O(1). Or O(logMlogN) and searching binary tree or smt. like
	// that. --pasky

	for (i = 0; i < wos->overrides_count; i++) {
		const WagonOverride *wo = &wos->overrides[i];
		int j;

		for (j = 0; j < wo->trains; j++) {
			if (wo->train_id[j] == overriding_engine)
				return wo->group;
		}
	}
	return NULL;
}

/**
 * Unload all wagon override sprite groups.
 */
void UnloadWagonOverrides(void)
{
	WagonOverrides *wos;
	WagonOverride *wo;
	EngineID engine;
	int i;

	for (engine = 0; engine < TOTAL_NUM_ENGINES; engine++) {
		wos = &_engine_wagon_overrides[engine];
		for (i = 0; i < wos->overrides_count; i++) {
			wo = &wos->overrides[i];
			wo->group = NULL;
			free(wo->train_id);
		}
		free(wos->overrides);
		wos->overrides_count = 0;
		wos->overrides = NULL;
	}
}

// 0 - 28 are cargos, 29 is default, 30 is the advert (purchase list)
// (It isn't and shouldn't be like this in the GRF files since new cargo types
// may appear in future - however it's more convenient to store it like this in
// memory. --pasky)
static const SpriteGroup *engine_custom_sprites[TOTAL_NUM_ENGINES][NUM_GLOBAL_CID];
static uint32 _engine_grf[TOTAL_NUM_ENGINES];

void SetCustomEngineSprites(EngineID engine, byte cargo, const SpriteGroup *group)
{
	assert(engine < TOTAL_NUM_ENGINES);
	if (engine_custom_sprites[engine][cargo] != NULL) {
		DEBUG(grf, 6)("SetCustomEngineSprites: engine `%d' cargo `%d' already has group -- replacing.", engine, cargo);
	}
	engine_custom_sprites[engine][cargo] = group;
}

/**
 * Unload all engine sprite groups.
 */
void UnloadCustomEngineSprites(void)
{
	EngineID engine;
	CargoID cargo;

	for (engine = 0; engine < TOTAL_NUM_ENGINES; engine++) {
		for (cargo = 0; cargo < NUM_GLOBAL_CID; cargo++) {
			engine_custom_sprites[engine][cargo] = NULL;
		}
		_engine_grf[engine] = 0;
	}
}

static const SpriteGroup *heli_rotor_custom_sprites[NUM_AIRCRAFT_ENGINES];

/** Load a rotor override sprite group for an aircraft */
void SetRotorOverrideSprites(EngineID engine, const SpriteGroup *group)
{
	assert(engine >= AIRCRAFT_ENGINES_INDEX);
	assert(engine < AIRCRAFT_ENGINES_INDEX + NUM_AIRCRAFT_ENGINES);

	if (heli_rotor_custom_sprites[engine - AIRCRAFT_ENGINES_INDEX] != NULL) {
		DEBUG(grf, 6)("SetRotorOverrideSprites: engine `%d' already has group -- replacing.", engine);
	}
	heli_rotor_custom_sprites[engine - AIRCRAFT_ENGINES_INDEX] = group;
}

/** Unload all rotor override sprite groups */
void UnloadRotorOverrideSprites(void)
{
	EngineID engine;

	/* Starting at AIRCRAFT_ENGINES_INDEX may seem pointless, but it means
	 * the context of EngineID is correct */
	for (engine = AIRCRAFT_ENGINES_INDEX; engine < AIRCRAFT_ENGINES_INDEX + NUM_AIRCRAFT_ENGINES; engine++) {
		heli_rotor_custom_sprites[engine - AIRCRAFT_ENGINES_INDEX] = NULL;
	}
}

void SetEngineGRF(EngineID engine, uint32 grfid)
{
	assert(engine < TOTAL_NUM_ENGINES);
	_engine_grf[engine] = grfid;
}

uint32 GetEngineGRFID(EngineID engine)
{
	assert(engine < TOTAL_NUM_ENGINES);
	return _engine_grf[engine];
}


static int MapOldSubType(const Vehicle *v)
{
	if (v->type != VEH_Train) return v->subtype;
	if (IsTrainEngine(v)) return 0;
	if (IsFreeWagon(v)) return 4;
	return 2;
}


/* TTDP style aircraft movement states for GRF Action 2 Var 0xE2 */
enum {
	AMS_TTDP_HANGER,
	AMS_TTDP_TO_HANGER,
	AMS_TTDP_TO_PAD1,
	AMS_TTDP_TO_PAD2,
	AMS_TTDP_TO_PAD3,
	AMS_TTDP_TO_ENTRY_2_AND_3,
	AMS_TTDP_TO_ENTRY_2_AND_3_AND_H,
	AMS_TTDP_TO_JUNCTION,
	AMS_TTDP_LEAVE_RUNWAY,
	AMS_TTDP_TO_INWAY,
	AMS_TTDP_TO_RUNWAY,
	AMS_TTDP_TO_OUTWAY,
	AMS_TTDP_WAITING,
	AMS_TTDP_TAKEOFF,
	AMS_TTDP_TO_TAKEOFF,
	AMS_TTDP_CLIMBING,
	AMS_TTDP_FLIGHT_APPROACH,
	AMS_TTDP_UNUSED_0x11,
	AMS_TTDP_FLIGHT_TO_TOWER,
	AMS_TTDP_UNUSED_0x13,
	AMS_TTDP_FLIGHT_FINAL,
	AMS_TTDP_FLIGHT_DESCENT,
	AMS_TTDP_BRAKING,
	AMS_TTDP_HELI_TAKEOFF_AIRPOPT,
	AMS_TTDP_HELI_TO_TAKEOFF_AIRPOPT,
	AMS_TTDP_HELI_LAND_AIRPOPT,
	AMS_TTDP_HELI_TAKEOFF_HELIPORT,
	AMS_TTDP_HELI_TO_TAKEOFF_HELIPORT,
	AMS_TTDP_HELI_LAND_HELIPORT,
};


/**
 * Map OTTD aircraft movement states to TTDPatch style movement states
 * (VarAction 2 Variable 0xE2)
 */
static byte MapAircraftMovementState(const Vehicle *v)
{
	const Station *st = GetStation(v->u.air.targetairport);
	byte amdflag = GetAirportMovingData(st->airport_type, v->u.air.pos)->flag;

	switch (v->u.air.state) {
		case HANGAR:
			/* The international airport is a special case as helicopters can land in
			 * front of the hanger. Helicopters also change their air.state to
			 * AMED_HELI_LOWER some time before actually descending. */

			/* This condition only occurs for helicopters, during descent,
			 * to a landing by the hanger of an international airport. */
			if (amdflag & AMED_HELI_LOWER) return AMS_TTDP_HELI_LAND_AIRPOPT;

			/* This condition only occurs for helicopters, before starting descent,
			 * to a landing by the hanger of an international airport. */
			if (amdflag & AMED_SLOWTURN) return AMS_TTDP_FLIGHT_TO_TOWER;

			// The final two conditions apply to helicopters or aircraft.
			/* Has reached hanger? */
			if (amdflag & AMED_EXACTPOS) return AMS_TTDP_HANGER;

			// Still moving towards hanger.
			return AMS_TTDP_TO_HANGER;

		case TERM1:
			if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD1;
			return AMS_TTDP_TO_JUNCTION;

		case TERM2:
			if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD2;
			return AMS_TTDP_TO_ENTRY_2_AND_3_AND_H;

		case TERM3:
		case TERM4:
		case TERM5:
		case TERM6:
			/* TTDPatch only has 3 terminals, so treat these states the same */
			if (amdflag & AMED_EXACTPOS) return AMS_TTDP_TO_PAD3;
			return AMS_TTDP_TO_ENTRY_2_AND_3_AND_H;

		case HELIPAD1:
		case HELIPAD2: // Will only occur for helicopters.
			if (amdflag & AMED_HELI_LOWER) return AMS_TTDP_HELI_LAND_AIRPOPT; // Descending.
			if (amdflag & AMED_SLOWTURN)   return AMS_TTDP_FLIGHT_TO_TOWER;   // Still hasn't started descent.
			return AMS_TTDP_TO_JUNCTION; // On the ground.

		case TAKEOFF: // Moving to takeoff position.
			return AMS_TTDP_TO_OUTWAY;

		case STARTTAKEOFF: // Accelerating down runway.
			return AMS_TTDP_TAKEOFF;

		case ENDTAKEOFF: // Ascent
			return AMS_TTDP_CLIMBING;

		case HELITAKEOFF: // Helicopter is moving to take off position.
			switch (st->airport_type) {
				case AT_SMALL:
				case AT_LARGE:
				case AT_METROPOLITAN:
				case AT_INTERNATIONAL:
					if (amdflag & AMED_HELI_RAISE) return AMS_TTDP_HELI_TAKEOFF_AIRPOPT;
					return AMS_TTDP_TO_JUNCTION;

				case AT_HELIPORT:
				case AT_OILRIG:
					return AMS_TTDP_HELI_TAKEOFF_HELIPORT;

				default:
					return AMS_TTDP_HELI_TAKEOFF_AIRPOPT;
			}

		case FLYING:
			return AMS_TTDP_FLIGHT_TO_TOWER;

		case LANDING: // Descent
			return AMS_TTDP_FLIGHT_DESCENT;

		case ENDLANDING: // On the runway braking
			if (amdflag & AMED_BRAKE) return AMS_TTDP_BRAKING;
			// Landed - moving off runway
			return AMS_TTDP_TO_INWAY;

		case HELILANDING:
		case HELIENDLANDING: // Helicoptor is decending.
			if (amdflag & AMED_HELI_LOWER) {
				switch (st->airport_type) {
					case AT_HELIPORT:
					case AT_OILRIG:
						return AMS_TTDP_HELI_LAND_HELIPORT;

					default:
						return AMS_TTDP_HELI_LAND_AIRPOPT;
				}
			}
			return AMS_TTDP_FLIGHT_TO_TOWER;

		default:
			return AMS_TTDP_HANGER;
	}
}


/* TTDP style aircraft movement action for GRF Action 2 Var 0xE6 */
enum {
	AMA_TTDP_IN_HANGER,
	AMA_TTDP_ON_PAD1,
	AMA_TTDP_ON_PAD2,
	AMA_TTDP_ON_PAD3,
	AMA_TTDP_HANGER_TO_PAD1,
	AMA_TTDP_HANGER_TO_PAD2,
	AMA_TTDP_HANGER_TO_PAD3,
	AMA_TTDP_LANDING_TO_PAD1,
	AMA_TTDP_LANDING_TO_PAD2,
	AMA_TTDP_LANDING_TO_PAD3,
	AMA_TTDP_PAD1_TO_HANGER,
	AMA_TTDP_PAD2_TO_HANGER,
	AMA_TTDP_PAD3_TO_HANGER,
	AMA_TTDP_PAD1_TO_TAKEOFF,
	AMA_TTDP_PAD2_TO_TAKEOFF,
	AMA_TTDP_PAD3_TO_TAKEOFF,
	AMA_TTDP_HANGER_TO_TAKOFF,
	AMA_TTDP_LANDING_TO_HANGER,
	AMA_TTDP_IN_FLIGHT,
};


/**
 * Map OTTD aircraft movement states to TTDPatch style movement actions
 * (VarAction 2 Variable 0xE6)
 * This is not fully supported yet but it's enough for Planeset.
 */
static byte MapAircraftMovementAction(const Vehicle *v)
{
	switch (v->u.air.state) {
		case HANGAR:
			return (v->cur_speed > 0) ? AMA_TTDP_LANDING_TO_HANGER : AMA_TTDP_IN_HANGER;

		case TERM1:
		case HELIPAD1:
			return (v->current_order.type == OT_LOADING) ? AMA_TTDP_ON_PAD1 : AMA_TTDP_LANDING_TO_PAD1;

		case TERM2:
		case HELIPAD2:
			return (v->current_order.type == OT_LOADING) ? AMA_TTDP_ON_PAD2 : AMA_TTDP_LANDING_TO_PAD2;

		case TERM3:
		case TERM4:
		case TERM5:
		case TERM6:
			return (v->current_order.type == OT_LOADING) ? AMA_TTDP_ON_PAD3 : AMA_TTDP_LANDING_TO_PAD3;

		case TAKEOFF:      // Moving to takeoff position
		case STARTTAKEOFF: // Accelerating down runway
		case ENDTAKEOFF:   // Ascent
		case HELITAKEOFF:
			// TODO Need to find which terminal (or hanger) we've come from. How?
			return AMA_TTDP_PAD1_TO_TAKEOFF;

		case FLYING:
			return AMA_TTDP_IN_FLIGHT;

		case LANDING:    // Descent
		case ENDLANDING: // On the runway braking
		case HELILANDING:
		case HELIENDLANDING:
			// TODO Need to check terminal we're landing to. Is it known yet?
			return (v->current_order.type == OT_GOTO_DEPOT) ?
				AMA_TTDP_LANDING_TO_HANGER : AMA_TTDP_LANDING_TO_PAD1;

		default:
			return AMA_TTDP_IN_HANGER;
	}
}


/* TTDP airport types. Used to map our types to TTDPatch's */
enum {
	ATP_TTDP_SMALL,
	ATP_TTDP_LARGE,
	ATP_TTDP_HELIPORT,
	ATP_TTDP_OILRIG,
};


/* Vehicle Resolver Functions */
static inline const Vehicle *GRV(const ResolverObject *object)
{
	return object->scope == VSG_SCOPE_SELF ? object->vehicle.self : object->vehicle.parent;
}


static uint32 VehicleGetRandomBits(const ResolverObject *object)
{
	return GRV(object) == NULL ? 0 : GRV(object)->random_bits;
}


static uint32 VehicleGetTriggers(const ResolverObject *object)
{
	return GRV(object) == NULL ? 0 : GRV(object)->waiting_triggers;
}


static void VehicleSetTriggers(const ResolverObject *object, int triggers)
{
	/* Evil cast to get around const-ness. This used to be achieved by an
	 * innocent looking function pointer cast... Currently I cannot see a
	 * way of avoiding this without removing consts deep within gui code.
	 */
	Vehicle *v = (Vehicle*)GRV(object);

	/* This function must only be called when processing triggers -- any
	 * other time is an error. */
	assert(object->trigger != 0);

	if (v != NULL) v->waiting_triggers = triggers;
}


static uint32 VehicleGetVariable(const ResolverObject *object, byte variable, byte parameter)
{
	const Vehicle *v = GRV(object);

	if (v == NULL) {
		/* Vehicle does not exist, so we're in a purchase list */
		switch (variable) {
			case 0x43: return _current_player; /* Owner information */
			case 0x46: return 0;               /* Motion counter */
			case 0xC4: return _cur_year;       /* Build year */
			case 0xDA: return INVALID_VEHICLE; /* Next vehicle */
			default:   return -1;
		}
	}

	/* Calculated vehicle parameters */
	switch (variable) {
		case 0x40: /* Get length of consist */
		case 0x41: /* Get length of same consecutive wagons */
			if (v->type != VEH_Train) return 1;

			{
				const Vehicle* u;
				byte chain_before = 0;
				byte chain_after  = 0;

				for (u = GetFirstVehicleInChain(v); u != v; u = u->next) {
					chain_before++;
					if (variable == 0x41 && u->engine_type != v->engine_type) chain_before = 0;
				}

				while (u->next != NULL && (variable == 0x40 || u->next->engine_type == v->engine_type)) {
					chain_after++;
					u = u->next;
				}

				return chain_before | chain_after << 8 | (chain_before + chain_after) << 16;
			}

		case 0x43: /* Player information */
			return v->owner;

		case 0x44: /* Aircraft information */
			if (v->type != VEH_Aircraft) return -1;

			{
				const Vehicle *w = v->next;
				uint16 altitude = v->z_pos - w->z_pos; /* Aircraft height - shadow height */
				byte airporttype;

				switch (GetStation(v->u.air.targetairport)->airport_type) {
					case AT_SMALL: airporttype = ATP_TTDP_SMALL; break;
					case AT_METROPOLITAN:
					case AT_INTERNATIONAL:
					case AT_LARGE: airporttype = ATP_TTDP_LARGE; break;
					case AT_HELIPORT: airporttype = ATP_TTDP_HELIPORT; break;
					case AT_OILRIG: airporttype = ATP_TTDP_OILRIG; break;
					default: airporttype = ATP_TTDP_LARGE; break;
				}

				return (altitude << 8) | airporttype;
			}

		case 0x46: /* Motion counter */
			return 0;
	}

	/* General vehicle properties */
	switch (variable - 0x80) {
		case 0x00: return v->type;
		case 0x01: return MapOldSubType(v);
		case 0x04: return v->index;
		case 0x05: return v->index & 0xFF;
		case 0x0A: return PackOrder(&v->current_order);
		case 0x0B: return PackOrder(&v->current_order) & 0xFF;
		case 0x0C: return v->num_orders;
		case 0x0D: return v->cur_order_index;
		case 0x10: return v->load_unload_time_rem;
		case 0x11: return v->load_unload_time_rem & 0xFF;
		case 0x12: return v->date_of_last_service;
		case 0x13: return v->date_of_last_service & 0xFF;
		case 0x14: return v->service_interval;
		case 0x15: return v->service_interval & 0xFF;
		case 0x16: return v->last_station_visited;
		case 0x17: return v->tick_counter;
		case 0x18: return v->max_speed;
		case 0x19: return v->max_speed & 0xFF;
		case 0x1A: return v->x_pos;
		case 0x1B: return v->x_pos & 0xFF;
		case 0x1C: return v->y_pos;
		case 0x1D: return v->y_pos & 0xFF;
		case 0x1E: return v->z_pos;
		case 0x1F: return v->direction;
		case 0x28: return v->cur_image;
		case 0x29: return v->cur_image & 0xFF;
		case 0x32: return v->vehstatus;
		case 0x33: return v->vehstatus;
		case 0x34: return v->cur_speed;
		case 0x35: return v->cur_speed & 0xFF;
		case 0x36: return v->subspeed;
		case 0x37: return v->acceleration;
		case 0x39: return v->cargo_type;
		case 0x3A: return v->cargo_cap;
		case 0x3B: return v->cargo_cap & 0xFF;
		case 0x3C: return v->cargo_count;
		case 0x3D: return v->cargo_count & 0xFF;
		case 0x3E: return v->cargo_source;
		case 0x3F: return v->cargo_days;
		case 0x40: return v->age;
		case 0x41: return v->age & 0xFF;
		case 0x42: return v->max_age;
		case 0x43: return v->max_age & 0xFF;
		case 0x44: return v->build_year;
		case 0x45: return v->unitnumber;
		case 0x46: return v->engine_type;
		case 0x47: return v->engine_type & 0xFF;
		case 0x48: return v->spritenum;
		case 0x49: return v->day_counter;
		case 0x4A: return v->breakdowns_since_last_service;
		case 0x4B: return v->breakdown_ctr;
		case 0x4C: return v->breakdown_delay;
		case 0x4D: return v->breakdown_chance;
		case 0x4E: return v->reliability;
		case 0x4F: return v->reliability & 0xFF;
		case 0x50: return v->reliability_spd_dec;
		case 0x51: return v->reliability_spd_dec & 0xFF;
		case 0x52: return v->profit_this_year;
		case 0x53: return v->profit_this_year & 0xFFFFFF;
		case 0x54: return v->profit_this_year & 0xFFFF;
		case 0x55: return v->profit_this_year & 0xFF;
		case 0x56: return v->profit_last_year;
		case 0x57: return v->profit_last_year & 0xFF;
		case 0x58: return v->profit_last_year;
		case 0x59: return v->profit_last_year & 0xFF;
		case 0x5A: return v->next == NULL ? INVALID_VEHICLE : v->next->index;
		case 0x5C: return v->value;
		case 0x5D: return v->value & 0xFFFFFF;
		case 0x5E: return v->value & 0xFFFF;
		case 0x5F: return v->value & 0xFF;
		case 0x60: return v->string_id;
		case 0x61: return v->string_id & 0xFF;
		case 0x72: return 0; // XXX Refit cycle
		case 0x7A: return v->random_bits;
		case 0x7B: return v->waiting_triggers;
	}

	/* Vehicle specific properties */
	switch (v->type) {
		case VEH_Train:
			switch (variable - 0x80) {
				case 0x62: return v->u.rail.track;
				case 0x66: return v->u.rail.railtype;
				case 0x73: return v->u.rail.cached_veh_length;
				case 0x74: return v->u.rail.cached_power;
				case 0x75: return v->u.rail.cached_power & 0xFFFFFF;
				case 0x76: return v->u.rail.cached_power & 0xFFFF;
				case 0x77: return v->u.rail.cached_power & 0xFF;
				case 0x7C: return v->first->index;
				case 0x7D: return v->first->index & 0xFF;
			}
			break;

		case VEH_Road:
			switch (variable - 0x80) {
				case 0x62: return v->u.road.state;
				case 0x64: return v->u.road.blocked_ctr;
				case 0x65: return v->u.road.blocked_ctr & 0xFF;
				case 0x66: return v->u.road.overtaking;
				case 0x67: return v->u.road.overtaking_ctr;
				case 0x68: return v->u.road.crashed_ctr;
				case 0x69: return v->u.road.crashed_ctr & 0xFF;
			}
			break;

		case VEH_Aircraft:
			switch (variable - 0x80) {
				case 0x62: return MapAircraftMovementState(v);  // Current movement state
				case 0x63: return v->u.air.targetairport;       // Airport to which the action refers
				case 0x66: return MapAircraftMovementAction(v); // Current movement action
			}
			break;
	}

	DEBUG(grf, 1)("Unhandled vehicle property 0x%X, type 0x%X", variable, v->type);

	return -1;
}


static uint32 VehicleResolveReal(const ResolverObject *object, uint num_loaded, uint num_loading, bool *in_motion)
{
	const Vehicle *v = object->vehicle.self;
	uint totalsets;
	uint set;

	if (v == NULL) {
		*in_motion = false;
		return 0;
	}

	if (v->type == VEH_Train) {
		*in_motion = GetFirstVehicleInChain(v)->current_order.type != OT_LOADING;
	} else {
		*in_motion = v->current_order.type != OT_LOADING;
	}

	totalsets = in_motion ? num_loaded : num_loading;

	if (v->cargo_count == v->cargo_cap || totalsets == 1) {
		set = totalsets - 1;
	} else if (v->cargo_count == 0 || totalsets == 2) {
		set = 0;
	} else {
		set = v->cargo_count * (totalsets - 2) / max(1, v->cargo_cap) + 1;
	}

	return set;
}


static inline void NewVehicleResolver(ResolverObject *res, const Vehicle *v)
{
	res->GetRandomBits = &VehicleGetRandomBits;
	res->GetTriggers   = &VehicleGetTriggers;
	res->SetTriggers   = &VehicleSetTriggers;
	res->GetVariable   = &VehicleGetVariable;
	res->ResolveReal   = &VehicleResolveReal;

	res->vehicle.self   = v;
	res->vehicle.parent = (v != NULL && v->type == VEH_Train) ? GetFirstVehicleInChain(v) : v;

	res->callback        = 0;
	res->callback_param1 = 0;
	res->callback_param2 = 0;
	res->last_value      = 0;
	res->trigger         = 0;
	res->reseed          = 0;
}


SpriteID GetCustomEngineSprite(EngineID engine, const Vehicle *v, Direction direction)
{
	const SpriteGroup *group;
	ResolverObject object;
	CargoID cargo = GC_PURCHASE;

	NewVehicleResolver(&object, v);

	if (v != NULL) {
		cargo = _global_cargo_id[_opt.landscape][v->cargo_type];
		assert(cargo != GC_INVALID);
	}

	group = engine_custom_sprites[engine][cargo];

	if (v != NULL && v->type == VEH_Train) {
		const SpriteGroup *overset = GetWagonOverrideSpriteSet(engine, v->u.rail.first_engine);

		if (overset != NULL) group = overset;
	}

	group = Resolve(group, &object);

	if ((group == NULL || group->type != SGT_RESULT) && cargo != GC_DEFAULT) {
		// This group is empty but perhaps there'll be a default one.
		group = Resolve(engine_custom_sprites[engine][GC_DEFAULT], &object);
	}

	if (group == NULL || group->type != SGT_RESULT) return 0;

	return group->g.result.sprite + (direction % group->g.result.num_sprites);
}


SpriteID GetRotorOverrideSprite(EngineID engine, const Vehicle *v)
{
	const SpriteGroup *group;
	ResolverObject object;

	assert(engine >= AIRCRAFT_ENGINES_INDEX);
	assert(engine < AIRCRAFT_ENGINES_INDEX + NUM_AIRCRAFT_ENGINES);

	/* Only valid for helicopters */
	assert((AircraftVehInfo(engine)->subtype & 1) == 0);

	NewVehicleResolver(&object, v);

	group = heli_rotor_custom_sprites[engine - AIRCRAFT_ENGINES_INDEX];
	group = Resolve(group, &object);

	if (group == NULL || group->type != SGT_RESULT) return 0;

	if (v == NULL) return group->g.result.sprite;

	return group->g.result.sprite + v->next->next->u.air.state;
}


/**
 * Check if a wagon is currently using a wagon override
 * @param v The wagon to check
 * @return true if it is using an override, false otherwise
 */
bool UsesWagonOverride(const Vehicle* v)
{
	assert(v->type == VEH_Train);
	return GetWagonOverrideSpriteSet(v->engine_type, v->u.rail.first_engine) != NULL;
}

/**
 * Evaluate a newgrf callback for vehicles
 * @param callback The callback to evalute
 * @param param1   First parameter of the callback
 * @param param2   Second parameter of the callback
 * @param engine   Engine type of the vehicle to evaluate the callback for
 * @param vehicle  The vehicle to evaluate the callback for, or NULL if it doesnt exist yet
 * @return The value the callback returned, or CALLBACK_FAILED if it failed
 */
uint16 GetVehicleCallback(byte callback, uint32 param1, uint32 param2, EngineID engine, const Vehicle *v)
{
	const SpriteGroup *group;
	ResolverObject object;
	CargoID cargo;

	NewVehicleResolver(&object, v);

	object.callback        = callback;
	object.callback_param1 = param1;
	object.callback_param2 = param2;

	cargo = (v == NULL) ? GC_PURCHASE : _global_cargo_id[_opt.landscape][v->cargo_type];

	group = engine_custom_sprites[engine][cargo];

	if (v != NULL && v->type == VEH_Train) {
		const SpriteGroup *overset = GetWagonOverrideSpriteSet(engine, v->u.rail.first_engine);

		if (overset != NULL) group = overset;
	}

	group = Resolve(group, &object);

	if ((group == NULL || group->type != SGT_CALLBACK) && cargo != GC_DEFAULT) {
		// This group is empty but perhaps there'll be a default one.
		group = Resolve(engine_custom_sprites[engine][GC_DEFAULT], &object);
	}

	if (group == NULL || group->type != SGT_CALLBACK)
		return CALLBACK_FAILED;

	return group->g.callback.result;
}


static void DoTriggerVehicle(Vehicle *v, VehicleTrigger trigger, byte base_random_bits, bool first)
{
	const SpriteGroup *group;
	ResolverObject object;
	CargoID cargo;
	byte new_random_bits;

	/* We can't trigger a non-existent vehicle... */
	assert(v != NULL);

	NewVehicleResolver(&object, v);

	object.trigger = trigger;

	cargo = _global_cargo_id[_opt.landscape][v->cargo_type];
	group = engine_custom_sprites[v->engine_type][cargo];

	if (v->type == VEH_Train) {
		const SpriteGroup *overset = GetWagonOverrideSpriteSet(v->engine_type, v->u.rail.first_engine);
		if (overset != NULL) group = overset;
	}

	group = Resolve(group, &object);
	if (group == NULL && v->cargo_type != GC_DEFAULT) {
		// This group is empty but perhaps there'll be a default one.
		group = Resolve(engine_custom_sprites[v->engine_type][GC_DEFAULT], &object);
	}

	/* Really return? */
	if (group == NULL) return;

	new_random_bits = Random();
	v->random_bits &= ~object.reseed;
	v->random_bits |= (first ? new_random_bits : base_random_bits) & object.reseed;

	switch (trigger) {
		case VEHICLE_TRIGGER_NEW_CARGO:
			/* All vehicles in chain get ANY_NEW_CARGO trigger now.
			 * So we call it for the first one and they will recurse. */
			/* Indexing part of vehicle random bits needs to be
			 * same for all triggered vehicles in the chain (to get
			 * all the random-cargo wagons carry the same cargo,
			 * i.e.), so we give them all the NEW_CARGO triggered
			 * vehicle's portion of random bits. */
			assert(first);
			DoTriggerVehicle(GetFirstVehicleInChain(v), VEHICLE_TRIGGER_ANY_NEW_CARGO, new_random_bits, false);
			break;

		case VEHICLE_TRIGGER_DEPOT:
			/* We now trigger the next vehicle in chain recursively.
			 * The random bits portions may be different for each
			 * vehicle in chain. */
			if (v->next != NULL) DoTriggerVehicle(v->next, trigger, 0, true);
			break;

		case VEHICLE_TRIGGER_EMPTY:
			/* We now trigger the next vehicle in chain
			 * recursively.  The random bits portions must be same
			 * for each vehicle in chain, so we give them all
			 * first chained vehicle's portion of random bits. */
			if (v->next != NULL) DoTriggerVehicle(v->next, trigger, first ? new_random_bits : base_random_bits, false);
			break;

		case VEHICLE_TRIGGER_ANY_NEW_CARGO:
			/* Now pass the trigger recursively to the next vehicle
			 * in chain. */
			assert(!first);
			if (v->next != NULL) DoTriggerVehicle(v->next, VEHICLE_TRIGGER_ANY_NEW_CARGO, base_random_bits, false);
			break;
	}
}

void TriggerVehicle(Vehicle *v, VehicleTrigger trigger)
{
	if (trigger == VEHICLE_TRIGGER_DEPOT) {
		// store that the vehicle entered a depot this tick
		VehicleEnteredDepotThisTick(v);
	}

	DoTriggerVehicle(v, trigger, 0, true);
}

StringID _engine_custom_names[TOTAL_NUM_ENGINES];

void SetCustomEngineName(EngineID engine, StringID name)
{
	assert(engine < lengthof(_engine_custom_names));
	_engine_custom_names[engine] = name;
}

void UnloadCustomEngineNames(void)
{
	EngineID i;
	for (i = 0; i < TOTAL_NUM_ENGINES; i++) {
		_engine_custom_names[i] = 0;
	}
}

StringID GetCustomEngineName(EngineID engine)
{
	return _engine_custom_names[engine] == 0 ? _engine_name_strings[engine] : _engine_custom_names[engine];
}

// Functions for changing the order of vehicle purchase lists
// This is currently only implemented for rail vehicles.
static EngineID engine_list_order[NUM_TRAIN_ENGINES];

void ResetEngineListOrder(void)
{
	EngineID i;

	for (i = 0; i < NUM_TRAIN_ENGINES; i++)
		engine_list_order[i] = i;
}

EngineID GetRailVehAtPosition(EngineID pos)
{
	return engine_list_order[pos];
}

void AlterRailVehListOrder(EngineID engine, EngineID target)
{
	EngineID i;
	bool moving = false;

	if (engine == target) return;

	// First, remove our ID from the list.
	for (i = 0; i < NUM_TRAIN_ENGINES - 1; i++) {
		if (engine_list_order[i] == engine)
			moving = true;
		if (moving)
			engine_list_order[i] = engine_list_order[i + 1];
	}

	// Now, insert it again, before the target engine.
	for (i = NUM_TRAIN_ENGINES - 1; i > 0; i--) {
		engine_list_order[i] = engine_list_order[i - 1];
		if (engine_list_order[i] == target) {
			engine_list_order[i - 1] = engine;
			break;
		}
	}
}