summaryrefslogtreecommitdiff
path: root/src/road_cmd.cpp
blob: f527a970e6491311d010b04b0c1bec0b0ac856a3 (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
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
/* $Id$ */

/** @file road_cmd.cpp */

#include "stdafx.h"
#include "openttd.h"
#include "bridge_map.h"
#include "bridge.h"
#include "cmd_helper.h"
#include "rail_map.h"
#include "road_map.h"
#include "sprite.h"
#include "table/sprites.h"
#include "table/strings.h"
#include "strings.h"
#include "functions.h"
#include "window.h"
#include "map.h"
#include "landscape.h"
#include "tile.h"
#include "town_map.h"
#include "vehicle.h"
#include "viewport.h"
#include "command.h"
#include "player.h"
#include "town.h"
#include "gfx.h"
#include "sound.h"
#include "yapf/yapf.h"
#include "depot.h"
#include "newgrf.h"
#include "station_map.h"
#include "tunnel_map.h"
#include "misc/autoptr.hpp"
#include "autoslope.h"
#include "transparency.h"

#define M(x) (1 << (x))
/* Level crossings may only be built on these slopes */
static const uint32 VALID_LEVEL_CROSSING_SLOPES = (M(SLOPE_SEN) | M(SLOPE_ENW) | M(SLOPE_NWS) | M(SLOPE_NS) | M(SLOPE_WSE) | M(SLOPE_EW) | M(SLOPE_FLAT));
#undef M

bool CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, Owner owner, bool *edge_road, RoadType rt)
{
	RoadBits present;
	RoadBits n;
	*edge_road = true;

	if (_game_mode == GM_EDITOR || remove == ROAD_NONE) return true;

	/* Water can always flood and towns can always remove "normal" road pieces.
	 * Towns are not be allowed to remove non "normal" road pieces, like tram
	 * tracks as that would result in trams that cannot turn. */
	if (_current_player == OWNER_WATER ||
			(rt == ROADTYPE_ROAD && !IsValidPlayer(_current_player))) return true;

	/* Only do the special processing if the road is owned
	 * by a town */
	if (owner != OWNER_TOWN) return (owner == OWNER_NONE) || CheckOwnership(owner);

	if (_cheats.magic_bulldozer.value) return true;

	/* Get a bitmask of which neighbouring roads has a tile */
	n = ROAD_NONE;
	present = GetAnyRoadBits(tile, rt);
	if (present & ROAD_NE && GetAnyRoadBits(TILE_ADDXY(tile, -1,  0), rt) & ROAD_SW) n |= ROAD_NE;
	if (present & ROAD_SE && GetAnyRoadBits(TILE_ADDXY(tile,  0,  1), rt) & ROAD_NW) n |= ROAD_SE;
	if (present & ROAD_SW && GetAnyRoadBits(TILE_ADDXY(tile,  1,  0), rt) & ROAD_NE) n |= ROAD_SW;
	if (present & ROAD_NW && GetAnyRoadBits(TILE_ADDXY(tile,  0, -1), rt) & ROAD_SE) n |= ROAD_NW;

	/* If 0 or 1 bits are set in n, or if no bits that match the bits to remove,
	 * then allow it */
	if ((n & (n - 1)) != 0 && (n & remove) != 0) {
		Town *t;
		*edge_road = false;
		/* you can remove all kind of roads with extra dynamite */
		if (_patches.extra_dynamite) return true;

		t = ClosestTownFromTile(tile, (uint)-1);

		SetDParam(0, t->index);
		_error_message = STR_2009_LOCAL_AUTHORITY_REFUSES;
		return false;
	}

	return true;
}

static bool CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, bool *edge_road, RoadType rt)
{
	return CheckAllowRemoveRoad(tile, remove, GetRoadOwner(tile, rt), edge_road, rt);
}

/** Delete a piece of road.
 * @param tile tile where to remove road from
 * @param flags operation to perform
 * @param p1 bit 0..3 road pieces to remove (RoadBits)
 *           bit 4..5 road type
 *           bit    6 ignore the fact that the tram track has not been removed
 *                    yet when removing the road bits when not actually doing
 *                    it. Makes it possible to test whether the road bits can
 *                    be removed from a level crossing without physically
 *                    removing the tram bits before the test.
 * @param p2 unused
 */
CommandCost CmdRemoveRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	/* cost for removing inner/edge -roads */
	static const uint16 road_remove_cost[2] = {50, 18};

	/* true if the roadpiece was always removeable,
	 * false if it was a center piece. Affects town ratings drop */
	bool edge_road;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	RoadType rt = (RoadType)GB(p1, 4, 2);
	if (!IsValidRoadType(rt)) return CMD_ERROR;

	Town *t = NULL;
	switch (GetTileType(tile)) {
		case MP_ROAD:
			if (_game_mode != GM_EDITOR && GetRoadOwner(tile, rt) == OWNER_TOWN) t = GetTownByTile(tile);
			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
			break;

		case MP_STATION:
			if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
			break;

		case MP_TUNNELBRIDGE:
			{
				TileIndex endtile;
				if (IsTunnel(tile)) {
					if (GetTunnelTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
					endtile = GetOtherTunnelEnd(tile);
				} else {
					if (GetBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
					endtile = GetOtherBridgeEnd(tile);
				}

				if (GetVehicleTunnelBridge(tile, endtile) != NULL) return CMD_ERROR;
			} break;

		default:
			return CMD_ERROR;
	}

	RoadBits pieces = Extract<RoadBits, 0>(p1);
	RoadTypes rts = GetRoadTypes(tile);
	/* The tile doesn't have the given road type */
	if (!HasBit(rts, rt)) return CMD_ERROR;

	if (!CheckAllowRemoveRoad(tile, pieces, &edge_road, rt)) return CMD_ERROR;

	/* check if you're allowed to remove the street owned by a town
	 * removal allowance depends on difficulty setting */
	if (!CheckforTownRating(flags, t, ROAD_REMOVE)) return CMD_ERROR;

	if (!IsTileType(tile, MP_ROAD)) {
		/* If it's the last roadtype, just clear the whole tile */
		if (rts == RoadTypeToRoadTypes(rt)) return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);

		CommandCost cost;
		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
			TileIndex other_end = IsTunnel(tile) ? GetOtherTunnelEnd(tile) : GetOtherBridgeEnd(tile);
			/* Pay for *every* tile of the bridge or tunnel */
			cost.AddCost((DistanceManhattan(IsTunnel(tile) ? GetOtherTunnelEnd(tile) : GetOtherBridgeEnd(tile), tile) + 1) * _price.remove_road);
			if (flags & DC_EXEC) {
				SetRoadTypes(other_end, GetRoadTypes(other_end) & ~RoadTypeToRoadTypes(rt));
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));

				/* Mark tiles diry that have been repaved */
				MarkTileDirtyByTile(tile);
				MarkTileDirtyByTile(other_end);
				if (IsBridge(tile)) {
					TileIndexDiff delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));

					for (TileIndex t = tile + delta; t != other_end; t += delta) MarkTileDirtyByTile(t);
				}
			}
		} else {
			cost.AddCost(_price.remove_road);
			if (flags & DC_EXEC) {
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));
				MarkTileDirtyByTile(tile);
			}
		}
		return CommandCost(cost);
	}

	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_NORMAL: {
			RoadBits present = GetRoadBits(tile, rt);
			RoadBits c = pieces;

			if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);

			if (GetTileSlope(tile, NULL) != SLOPE_FLAT  &&
					(present == ROAD_Y || present == ROAD_X)) {
				c |= (RoadBits)((c & 0xC) >> 2);
				c |= (RoadBits)((c & 0x3) << 2);
			}

			/* limit the bits to delete to the existing bits. */
			c &= present;
			if (c == ROAD_NONE) return CMD_ERROR;

			if (flags & DC_EXEC) {
				ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);

				present ^= c;
				if (present == ROAD_NONE) {
					RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
					if (rts == ROADTYPES_NONE) {
						/* Includes MarkTileDirtyByTile() */
						DoClearSquare(tile);
					} else {
						SetRoadBits(tile, ROAD_NONE, rt);
						SetRoadTypes(tile, rts);
						MarkTileDirtyByTile(tile);
					}
				} else {
					/* When bits are removed, you *always* end up with something that
					 * is not a complete straight road tile. However, trams do not have
					 * onewayness, so they cannot remove it either. */
					if (rt != ROADTYPE_TRAM) SetDisallowedRoadDirections(tile, DRD_NONE);
					SetRoadBits(tile, present, rt);
					MarkTileDirtyByTile(tile);
				}
			}
			return CommandCost(CountBits(c) * _price.remove_road);
		}

		case ROAD_TILE_CROSSING: {
			if (pieces & ComplementRoadBits(GetCrossingRoadBits(tile))) {
				return CMD_ERROR;
			}

			/* Don't allow road to be removed from the crossing when there is tram;
			 * we can't draw the crossing without trambits ;) */
			if (rt == ROADTYPE_ROAD && HasBit(GetRoadTypes(tile), ROADTYPE_TRAM) && ((flags & DC_EXEC) || !HasBit(p1, 6))) return CMD_ERROR;

			if (flags & DC_EXEC) {
				if (rt == ROADTYPE_ROAD) {
					ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
				}

				RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
				if (rts == ROADTYPES_NONE) {
					MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailType(tile));
				} else {
					SetRoadTypes(tile, rts);
				}
				MarkTileDirtyByTile(tile);
				YapfNotifyTrackLayoutChange(tile, FindFirstTrack(GetTrackBits(tile)));
			}
			return CommandCost(_price.remove_road * 2);
		}

		default:
		case ROAD_TILE_DEPOT:
			return CMD_ERROR;
	}
}


static const RoadBits _valid_tileh_slopes_road[][15] = {
	/* set of normal ones */
	{
		ROAD_ALL,  // SLOPE_FLAT
		ROAD_NONE, // SLOPE_W
		ROAD_NONE, // SLOPE_S

		ROAD_X,    // SLOPE_SW
		ROAD_NONE, // SLOPE_E
		ROAD_NONE, // SLOPE_EW

		ROAD_Y,    // SLOPE_SE
		ROAD_NONE, // SLOPE_WSE
		ROAD_NONE, // SLOPE_N

		ROAD_Y,    // SLOPE_NW
		ROAD_NONE, // SLOPE_NS
		ROAD_NONE, // SLOPE_NE

		ROAD_X,    // SLOPE_ENW
		ROAD_NONE, // SLOPE_SEN
		ROAD_NONE  // SLOPE_ELEVATED
	},
	/* allowed road for an evenly raised platform */
	{
		ROAD_NONE,         // SLOPE_FLAT
		ROAD_SW | ROAD_NW, // SLOPE_W
		ROAD_SW | ROAD_SE, // SLOPE_S

		ROAD_Y  | ROAD_SW, // SLOPE_SW
		ROAD_SE | ROAD_NE, // SLOPE_E
		ROAD_ALL,          // SLOPE_EW

		ROAD_X  | ROAD_SE, // SLOPE_SE
		ROAD_ALL,          // SLOPE_WSE
		ROAD_NW | ROAD_NE, // SLOPE_N

		ROAD_X  | ROAD_NW, // SLOPE_NW
		ROAD_ALL,          // SLOPE_NS
		ROAD_ALL,          // SLOPE_NE

		ROAD_Y  | ROAD_NE, // SLOPE_ENW
		ROAD_ALL,          // SLOPE_SEN
		ROAD_ALL           // SLOPE_ELEVATED
	},
	/* Singe bits on slopes */
	{
		ROAD_ALL,          // SLOPE_FLAT
		ROAD_NE | ROAD_SE, // SLOPE_W
		ROAD_NE | ROAD_NW, // SLOPE_S

		ROAD_NE,           // SLOPE_SW
		ROAD_NW | ROAD_SW, // SLOPE_E
		ROAD_ALL,          // SLOPE_EW

		ROAD_NW,           // SLOPE_SE
		ROAD_ALL,          // SLOPE_WSE
		ROAD_SE | ROAD_SW, // SLOPE_N

		ROAD_SE,           // SLOPE_NW
		ROAD_ALL,          // SLOPE_NS
		ROAD_ALL,          // SLOPE_NE

		ROAD_SW,           // SLOPE_ENW
		ROAD_ALL,          // SLOPE_SEN
		ROAD_ALL,          // SLOPE_ELEVATED
	},
};

/**
 * Calculate the costs for roads on slopes
 *  Aside modify the RoadBits to fit on the slopes
 *
 * @note The RoadBits are modified too!
 * @param tileh The current slope
 * @param pieces The RoadBits we want to add
 * @param existing The existent RoadBits
 * @return The costs for these RoadBits on this slope
 */
static CommandCost CheckRoadSlope(Slope tileh, RoadBits* pieces, RoadBits existing)
{
	if (IsSteepSlope(tileh)) {
		/* Force straight roads. */
		*pieces |= MirrorRoadBits(*pieces);

		if (existing == ROAD_NONE || existing == *pieces) {
			if (*pieces == ROAD_X || *pieces == ROAD_Y) return _price.terraform;
		}
		return CMD_ERROR;
	}

	RoadBits road_bits = *pieces | existing;

	/* Single bits on slopes.
	 * We check for the roads that need at least 2 bits */
	if (_patches.build_on_slopes && !_is_old_ai_player &&
			existing == ROAD_NONE && CountBits(*pieces) == 1 &&
			(_valid_tileh_slopes_road[2][tileh] & *pieces) == ROAD_NONE) {
		return CommandCost(_price.terraform);
	}

	/* no special foundation */
	if ((~_valid_tileh_slopes_road[0][tileh] & road_bits) == ROAD_NONE) {
		/* force that all bits are set when we have slopes */
		if (tileh != SLOPE_FLAT) *pieces |= _valid_tileh_slopes_road[0][tileh];
		return CommandCost(); // no extra cost
	}

	/* foundation is used. Whole tile is leveled up */
	if ((~_valid_tileh_slopes_road[1][tileh] & road_bits) == ROAD_NONE) {
		return CommandCost(existing != ROAD_NONE ? (Money)0 : _price.terraform);
	}

	/* Force straight roads. */
	*pieces |= MirrorRoadBits(*pieces);

	/* partly leveled up tile, only if there's no road on that tile */
	if ((existing == ROAD_NONE || existing == *pieces) && (tileh == SLOPE_W || tileh == SLOPE_S || tileh == SLOPE_E || tileh == SLOPE_N)) {
		if (*pieces == ROAD_X || *pieces == ROAD_Y) return _price.terraform;
	}
	return CMD_ERROR;
}

/** Build a piece of road.
 * @param tile tile where to build road
 * @param flags operation to perform
 * @param p1 bit 0..3 road pieces to build (RoadBits)
 *           bit 4..5 road type
 *           bit 6..7 disallowed directions to toggle
 * @param p2 the town that is building the road (0 if not applicable)
 */
CommandCost CmdBuildRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	CommandCost cost;
	CommandCost ret;
	RoadBits existing = ROAD_NONE;
	RoadBits all_bits = ROAD_NONE;
	Slope tileh;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	/* Road pieces are max 4 bitset values (NE, NW, SE, SW) and town can only be non-zero
	 * if a non-player is building the road */
	if ((IsValidPlayer(_current_player) && p2 != 0) || (_current_player == OWNER_TOWN && !IsValidTownID(p2))) return CMD_ERROR;

	RoadBits pieces = Extract<RoadBits, 0>(p1);

	RoadType rt = (RoadType)GB(p1, 4, 2);
	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	DisallowedRoadDirections toggle_drd = (DisallowedRoadDirections)GB(p1, 6, 2);

	tileh = GetTileSlope(tile, NULL);

	switch (GetTileType(tile)) {
		case MP_ROAD:
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);
					if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

					all_bits = GetAllRoadBits(tile);
					if (!HasBit(GetRoadTypes(tile), rt)) break;

					existing = GetRoadBits(tile, rt);
					RoadBits merged = existing | pieces;
					bool crossing = (merged != ROAD_X && merged != ROAD_Y);
					if (rt != ROADTYPE_TRAM && (GetDisallowedRoadDirections(tile) != DRD_NONE || toggle_drd != DRD_NONE) && crossing) {
						/* Junctions cannot be one-way */
						return_cmd_error(STR_ERR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);
					}
					if ((existing & pieces) == pieces) {
						/* We only want to set the (dis)allowed road directions */
						if (toggle_drd != DRD_NONE && rt != ROADTYPE_TRAM && GetRoadOwner(tile, ROADTYPE_ROAD) == _current_player) {
							if (crossing) return_cmd_error(STR_ERR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);

							/* Ignore half built tiles */
							if (flags & DC_EXEC && rt != ROADTYPE_TRAM && (existing == ROAD_X || existing == ROAD_Y)) {
								SetDisallowedRoadDirections(tile, GetDisallowedRoadDirections(tile) ^ toggle_drd);
								MarkTileDirtyByTile(tile);
							}
							return CommandCost();
						}
						return_cmd_error(STR_1007_ALREADY_BUILT);
					}
				} break;

				case ROAD_TILE_CROSSING:
					if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
					all_bits = GetCrossingRoadBits(tile);
					if (pieces & ComplementRoadBits(all_bits)) goto do_clear;
					break;

				default:
				case ROAD_TILE_DEPOT:
					goto do_clear;
			}
			break;

		case MP_RAILWAY: {
			Axis roaddir;

			if (IsSteepSlope(tileh)) {
				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
			}

			/* Level crossings may only be built on these slopes */
			if (!HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh)) {
				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
			}

			if (GetRailTileType(tile) != RAIL_TILE_NORMAL) goto do_clear;
			switch (GetTrackBits(tile)) {
				case TRACK_BIT_X:
					if (pieces & ROAD_X) goto do_clear;
					roaddir = AXIS_Y;
					break;

				case TRACK_BIT_Y:
					if (pieces & ROAD_Y) goto do_clear;
					roaddir = AXIS_X;
					break;

				default: goto do_clear;
			}

			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

			if (flags & DC_EXEC) {
				YapfNotifyTrackLayoutChange(tile, FindFirstTrack(GetTrackBits(tile)));
				/* Always add road to the roadtypes (can't draw without it) */
				MakeRoadCrossing(tile, _current_player, _current_player, _current_player, GetTileOwner(tile), roaddir, GetRailType(tile), RoadTypeToRoadTypes(rt) | ROADTYPES_ROAD, p2);
				MarkTileDirtyByTile(tile);
			}
			return CommandCost(_price.build_road * (rt == ROADTYPE_ROAD ? 2 : 4));
		}

		case MP_STATION:
			if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
			if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
			/* Don't allow "upgrading" the roadstop when vehicles are already driving on it */
			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
			break;

		case MP_TUNNELBRIDGE:
			{
				TileIndex endtile;
				if (IsTunnel(tile)) {
					if (GetTunnelTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
					endtile = GetOtherTunnelEnd(tile);
				} else {
					if (GetBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
					endtile = GetOtherBridgeEnd(tile);
				}
				if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
				/* Don't allow "upgrading" the bridge/tunnel when vehicles are already driving on it */
				if (GetVehicleTunnelBridge(tile, endtile) != NULL) return CMD_ERROR;
			} break;

		default:
do_clear:;
			ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
			if (CmdFailed(ret)) return ret;
			cost.AddCost(ret);
	}

	if (all_bits != pieces) {
		/* Check the foundation/slopes when adding road/tram bits */
		ret = CheckRoadSlope(tileh, &pieces, all_bits | existing);
		/* Return an error if we need to build a foundation (ret != 0) but the
		 * current patch-setting is turned off (or stupid AI@work) */
		if (CmdFailed(ret) || (ret.GetCost() != 0 && (!_patches.build_on_slopes || _is_old_ai_player))) {
			return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
		}
		cost.AddCost(ret);
	}

	if (IsTileType(tile, MP_ROAD)) {
		/* Don't put the pieces that already exist */
		pieces &= ComplementRoadBits(existing);
	}

	cost.AddCost(CountBits(pieces) * _price.build_road);
	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
		/* Pay for *every* tile of the bridge or tunnel */
		cost.MultiplyCost(DistanceManhattan(IsTunnel(tile) ? GetOtherTunnelEnd(tile) : GetOtherBridgeEnd(tile), tile));
	}

	if (flags & DC_EXEC) {
		switch (GetTileType(tile)) {
			case MP_ROAD: {
				RoadTileType rtt = GetRoadTileType(tile);
				if (existing == ROAD_NONE || rtt == ROAD_TILE_CROSSING) {
					SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));
					SetRoadOwner(tile, rt, _current_player);
					if (_current_player == OWNER_TOWN && rt == ROADTYPE_ROAD) SetTownIndex(tile, p2);
				}
				if (rtt != ROAD_TILE_CROSSING) SetRoadBits(tile, existing | pieces, rt);
			} break;

			case MP_TUNNELBRIDGE: {
				TileIndex other_end = IsTunnel(tile) ? GetOtherTunnelEnd(tile) : GetOtherBridgeEnd(tile);

				SetRoadTypes(other_end, GetRoadTypes(other_end) | RoadTypeToRoadTypes(rt));
				SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));

				/* Mark tiles diry that have been repaved */
				MarkTileDirtyByTile(other_end);
				MarkTileDirtyByTile(tile);
				if (IsBridge(tile)) {
					TileIndexDiff delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));

					for (TileIndex t = tile + delta; t != other_end; t += delta) MarkTileDirtyByTile(t);
				}
			} break;

			case MP_STATION:
				SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));
				break;

			default:
				MakeRoadNormal(tile, pieces, RoadTypeToRoadTypes(rt), p2, _current_player, _current_player, _current_player);
				break;
		}

		if (rt != ROADTYPE_TRAM && IsTileType(tile, MP_ROAD) && GetRoadTileType(tile) == ROAD_TILE_NORMAL) {
			existing |= pieces;
			SetDisallowedRoadDirections(tile, (existing == ROAD_X || existing == ROAD_Y) ?
					GetDisallowedRoadDirections(tile) ^ toggle_drd : DRD_NONE);
		}

		MarkTileDirtyByTile(tile);
	}
	return cost;
}

/**
 * Switches the rail type on a level crossing.
 * @param tile        The tile on which the railtype is to be convert.
 * @param totype      The railtype we want to convert to
 * @param exec        Switches between test and execute mode
 * @return            The cost and state of the operation
 * @retval CMD_ERROR  An error occured during the operation.
 */
CommandCost DoConvertStreetRail(TileIndex tile, RailType totype, bool exec)
{
	/* not a railroad crossing? */
	if (!IsLevelCrossing(tile)) return CMD_ERROR;

	if (exec) {
		SetRailType(tile, totype);
		MarkTileDirtyByTile(tile);
		YapfNotifyTrackLayoutChange(tile, FindFirstTrack(GetCrossingRailBits(tile)));
		VehicleFromPos(tile, &tile, UpdateTrainPowerProc);
	}

	return CommandCost(RailConvertCost(GetRailType(tile), totype));
}


/** Build a long piece of road.
 * @param end_tile end tile of drag
 * @param flags operation to perform
 * @param p1 start tile of drag
 * @param p2 various bitstuffed elements
 * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1)
 * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2)
 * - p2 = (bit 2) - direction: 0 = along x-axis, 1 = along y-axis (p2 & 4)
 * - p2 = (bit 3 + 4) - road type
 * - p2 = (bit 5) - set road direction
 */
CommandCost CmdBuildLongRoad(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
{
	TileIndex start_tile, tile;
	CommandCost cost, ret;
	bool had_bridge = false;
	bool had_tunnel = false;
	bool had_success = false;
	DisallowedRoadDirections drd = DRD_NORTHBOUND;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	if (p1 >= MapSize()) return CMD_ERROR;

	start_tile = p1;
	RoadType rt = (RoadType)GB(p2, 3, 2);
	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	/* Only drag in X or Y direction dictated by the direction variable */
	if (!HasBit(p2, 2) && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (HasBit(p2, 2)  && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis

	/* Swap start and ending tile, also the half-tile drag var (bit 0 and 1) */
	if (start_tile > end_tile || (start_tile == end_tile && HasBit(p2, 0))) {
		TileIndex t = start_tile;
		start_tile = end_tile;
		end_tile = t;
		p2 ^= IsInsideMM(p2 & 3, 1, 3) ? 3 : 0;
		drd = DRD_SOUTHBOUND;
	}

	/* On the X-axis, we have to swap the initial bits, so they
	 * will be interpreted correctly in the GTTS. Futhermore
	 * when you just 'click' on one tile to build them. */
	if (HasBit(p2, 2) == (start_tile == end_tile && HasBit(p2, 0) == HasBit(p2, 1))) drd ^= DRD_BOTH;
	/* No disallowed direction bits have to be toggled */
	if (!HasBit(p2, 5)) drd = DRD_NONE;

	tile = start_tile;
	/* Start tile is the small number. */
	for (;;) {
		RoadBits bits = HasBit(p2, 2) ? ROAD_Y : ROAD_X;

		if (tile == end_tile && !HasBit(p2, 1)) bits &= ROAD_NW | ROAD_NE;
		if (tile == start_tile && HasBit(p2, 0)) bits &= ROAD_SE | ROAD_SW;

		ret = DoCommand(tile, drd << 6 | rt << 4 | bits, 0, flags, CMD_BUILD_ROAD);
		if (CmdFailed(ret)) {
			if (_error_message != STR_1007_ALREADY_BUILT) return CMD_ERROR;
			_error_message = INVALID_STRING_ID;
		} else {
			had_success = true;
			/* Only pay for the upgrade on one side of the bridges and tunnels */
			if (IsTileType(tile, MP_TUNNELBRIDGE)) {
				if (IsBridge(tile)) {
					if ((!had_bridge || GetBridgeRampDirection(tile) == DIAGDIR_SE || GetBridgeRampDirection(tile) == DIAGDIR_SW)) {
						cost.AddCost(ret);
					}
					had_bridge = true;
				} else {
					if ((!had_tunnel || GetTunnelDirection(tile) == DIAGDIR_SE || GetTunnelDirection(tile) == DIAGDIR_SW)) {
						cost.AddCost(ret);
					}
					had_tunnel = true;
				}
			} else {
				cost.AddCost(ret);
			}
		}

		if (tile == end_tile) break;

		tile += HasBit(p2, 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	return !had_success ? CMD_ERROR : cost;
}

/** Remove a long piece of road.
 * @param end_tile end tile of drag
 * @param flags operation to perform
 * @param p1 start tile of drag
 * @param p2 various bitstuffed elements
 * - p2 = (bit 0) - start tile starts in the 2nd half of tile (p2 & 1)
 * - p2 = (bit 1) - end tile starts in the 2nd half of tile (p2 & 2)
 * - p2 = (bit 2) - direction: 0 = along x-axis, 1 = along y-axis (p2 & 4)
 * - p2 = (bit 3 + 4) - road type
 */
CommandCost CmdRemoveLongRoad(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
{
	TileIndex start_tile, tile;
	CommandCost cost, ret, money;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	if (p1 >= MapSize()) return CMD_ERROR;

	start_tile = p1;
	RoadType rt = (RoadType)GB(p2, 3, 2);
	if (!IsValidRoadType(rt)) return CMD_ERROR;

	/* Only drag in X or Y direction dictated by the direction variable */
	if (!HasBit(p2, 2) && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (HasBit(p2, 2)  && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis

	/* Swap start and ending tile, also the half-tile drag var (bit 0 and 1) */
	if (start_tile > end_tile || (start_tile == end_tile && HasBit(p2, 0))) {
		TileIndex t = start_tile;
		start_tile = end_tile;
		end_tile = t;
		p2 ^= IsInsideMM(p2 & 3, 1, 3) ? 3 : 0;
	}

	money.AddCost(GetAvailableMoneyForCommand());
	tile = start_tile;
	/* Start tile is the small number. */
	for (;;) {
		RoadBits bits = HasBit(p2, 2) ? ROAD_Y : ROAD_X;

		if (tile == end_tile && !HasBit(p2, 1)) bits &= ROAD_NW | ROAD_NE;
		if (tile == start_tile && HasBit(p2, 0)) bits &= ROAD_SE | ROAD_SW;

		/* try to remove the halves. */
		if (bits != 0) {
			ret = DoCommand(tile, rt << 4 | bits, 0, flags & ~DC_EXEC, CMD_REMOVE_ROAD);
			if (CmdSucceeded(ret)) {
				if (flags & DC_EXEC) {
					money.AddCost(-ret.GetCost());
					if (money.GetCost() < 0) {
						_additional_cash_required = DoCommand(end_tile, start_tile, p2, flags & ~DC_EXEC, CMD_REMOVE_LONG_ROAD).GetCost();
						return cost;
					}
					DoCommand(tile, rt << 4 | bits, 0, flags, CMD_REMOVE_ROAD);
				}
				cost.AddCost(ret);
			}
		}

		if (tile == end_tile) break;

		tile += HasBit(p2, 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	return (cost.GetCost() == 0) ? CMD_ERROR : cost;
}

/** Build a road depot.
 * @param tile tile where to build the depot
 * @param flags operation to perform
 * @param p1 bit 0..1 entrance direction (DiagDirection)
 *           bit 2..3 road type
 * @param p2 unused
 *
 * @todo When checking for the tile slope,
 * distingush between "Flat land required" and "land sloped in wrong direction"
 */
CommandCost CmdBuildRoadDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
{
	CommandCost cost;
	Slope tileh;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	DiagDirection dir = Extract<DiagDirection, 0>(p1);
	RoadType rt = (RoadType)GB(p1, 2, 2);

	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	tileh = GetTileSlope(tile, NULL);
	if (tileh != SLOPE_FLAT && (
				!_patches.build_on_slopes ||
				IsSteepSlope(tileh) ||
				!CanBuildDepotByTileh(dir, tileh)
			)) {
		return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
	}

	cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
	if (CmdFailed(cost)) return CMD_ERROR;

	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);

	Depot *dep = new Depot(tile);
	if (dep == NULL) return CMD_ERROR;
	AutoPtrT<Depot> d_auto_delete = dep;

	if (flags & DC_EXEC) {
		dep->town_index = ClosestTownFromTile(tile, (uint)-1)->index;

		MakeRoadDepot(tile, _current_player, dir, rt);
		MarkTileDirtyByTile(tile);
		d_auto_delete.Detach();
	}
	return cost.AddCost(_price.build_road_depot);
}

static CommandCost RemoveRoadDepot(TileIndex tile, uint32 flags)
{
	if (!CheckTileOwnership(tile) && _current_player != OWNER_WATER)
		return CMD_ERROR;

	if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;

	if (flags & DC_EXEC) {
		DoClearSquare(tile);
		delete GetDepotByTile(tile);
	}

	return CommandCost(_price.remove_road_depot);
}

static CommandCost ClearTile_Road(TileIndex tile, byte flags)
{
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_NORMAL: {
			RoadBits b = GetAllRoadBits(tile);

			/* Clear the road if only one piece is on the tile OR the AI tries
			 * to clear town road OR we are not using the DC_AUTO flag */
			if ((CountBits(b) == 1 && GetRoadBits(tile, ROADTYPE_TRAM) == ROAD_NONE) ||
			    ((flags & DC_AI_BUILDING) && IsTileOwner(tile, OWNER_TOWN)) ||
			    !(flags & DC_AUTO)
				) {
				RoadTypes rts = GetRoadTypes(tile);
				CommandCost ret;
				for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
					if (HasBit(rts, rt)) {
						CommandCost tmp_ret = DoCommand(tile, rt << 4 | GetRoadBits(tile, rt), 0, flags, CMD_REMOVE_ROAD);
						if (CmdFailed(tmp_ret)) return tmp_ret;
						ret.AddCost(tmp_ret);
					}
				}
				return ret;
			}
			return_cmd_error(STR_1801_MUST_REMOVE_ROAD_FIRST);
		}

		case ROAD_TILE_CROSSING: {
			RoadTypes rts = GetRoadTypes(tile);
			CommandCost ret;

			if (flags & DC_AUTO) return_cmd_error(STR_1801_MUST_REMOVE_ROAD_FIRST);

			/* Must iterate over the roadtypes in a reverse manner because
			 * tram tracks must be removed before the road bits. */
			for (RoadType rt = ROADTYPE_HWAY; rt >= ROADTYPE_ROAD; rt--) {
				if (HasBit(rts, rt)) {
					CommandCost tmp_ret = DoCommand(tile, 1 << 6 | rt << 4 | GetCrossingRoadBits(tile), 0, flags, CMD_REMOVE_ROAD);
					if (CmdFailed(tmp_ret)) return tmp_ret;
					ret.AddCost(tmp_ret);
				}
			}

			if (flags & DC_EXEC) {
				DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
			}
			return ret;
		}

		default:
		case ROAD_TILE_DEPOT:
			if (flags & DC_AUTO) {
				return_cmd_error(STR_2004_BUILDING_MUST_BE_DEMOLISHED);
			}
			return RemoveRoadDepot(tile, flags);
	}
}


struct DrawRoadTileStruct {
	uint16 image;
	byte subcoord_x;
	byte subcoord_y;
};

#include "table/road_land.h"


Foundation GetRoadFoundation(Slope tileh, RoadBits bits)
{
	if (!IsSteepSlope(tileh)) {
		if ((~_valid_tileh_slopes_road[0][tileh] & bits) == 0) {
			/* As one can remove a single road piece when in a corner on a foundation as
			 * it is on a sloped piece of landscape, one creates a state that cannot be
			 * created directly, but the state itself is still perfectly drawable.
			 * However, as we do not want this to be build directly, we need to check
			 * for that situation in here. */
			return (tileh != 0 && CountBits(bits) == 1) ? FOUNDATION_LEVELED : FOUNDATION_NONE;
		}
		if ((~_valid_tileh_slopes_road[1][tileh] & bits) == 0) return FOUNDATION_LEVELED;
	}

	return (bits == ROAD_X ? FOUNDATION_INCLINED_X : FOUNDATION_INCLINED_Y);
}

const byte _road_sloped_sprites[14] = {
	0,  0,  2,  0,
	0,  1,  0,  0,
	3,  0,  0,  0,
	0,  0
};

/**
 * Whether to draw unpaved roads regardless of the town zone.
 * By default, OpenTTD always draws roads as unpaved if they are on a desert
 * tile or above the snowline. Newgrf files, however, can set a bit that allows
 * paved roads to be built on desert tiles as they would be on grassy tiles.
 *
 * @param tile The tile the road is on
 * @param roadside What sort of road this is
 * @return True if the road should be drawn unpaved regardless of the roadside.
 */
static bool AlwaysDrawUnpavedRoads(TileIndex tile, Roadside roadside)
{
	return (IsOnSnow(tile) &&
			!(_opt.landscape == LT_TROPIC && HasGrfMiscBit(GMB_DESERT_PAVED_ROADS) &&
				roadside != ROADSIDE_BARREN && roadside != ROADSIDE_GRASS && roadside != ROADSIDE_GRASS_ROAD_WORKS));
}

/**
 * Draws the catenary for the given tile
 * @param ti   information about the tile (slopes, height etc)
 * @param tram the roadbits for the tram
 */
void DrawTramCatenary(TileInfo *ti, RoadBits tram)
{
	/* Don't draw the catenary under a low bridge */
	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_BUILDINGS)) {
		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));

		if (height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) return;
	}

	SpriteID front;
	SpriteID back;

	if (ti->tileh != SLOPE_FLAT) {
		back  = SPR_TRAMWAY_BACK_WIRES_SLOPED  + _road_sloped_sprites[ti->tileh - 1];
		front = SPR_TRAMWAY_FRONT_WIRES_SLOPED + _road_sloped_sprites[ti->tileh - 1];
	} else {
		back  = SPR_TRAMWAY_BASE + _road_backpole_sprites_1[tram];
		front = SPR_TRAMWAY_BASE + _road_frontwire_sprites_1[tram];
	}

	AddSortableSpriteToDraw(back,  PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_BUILDINGS));
	AddSortableSpriteToDraw(front, PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_BUILDINGS));
}

/**
 * Draws details on/around the road
 * @param img the sprite to draw
 * @param ti  the tile to draw on
 * @param dx  the offset from the top of the BB of the tile
 * @param dy  the offset from the top of the BB of the tile
 * @param h   the height of the sprite to draw
 */
static void DrawRoadDetail(SpriteID img, TileInfo *ti, int dx, int dy, int h)
{
	int x = ti->x | dx;
	int y = ti->y | dy;
	byte z = ti->z;
	if (ti->tileh != SLOPE_FLAT) z = GetSlopeZ(x, y);
	AddSortableSpriteToDraw(img, PAL_NONE, x, y, 2, 2, h, z);
}

/**
 * Draw ground sprite and road pieces
 * @param ti TileInfo
 */
static void DrawRoadBits(TileInfo* ti)
{
	RoadBits road = GetRoadBits(ti->tile, ROADTYPE_ROAD);
	RoadBits tram = GetRoadBits(ti->tile, ROADTYPE_TRAM);

	const DrawRoadTileStruct *drts;
	SpriteID image = 0;
	SpriteID pal = PAL_NONE;
	Roadside roadside;

	if (ti->tileh != SLOPE_FLAT) {
		DrawFoundation(ti, GetRoadFoundation(ti->tileh, road | tram));

		/* DrawFoundation() modifies ti.
		 * Default sloped sprites.. */
		if (ti->tileh != SLOPE_FLAT) image = _road_sloped_sprites[ti->tileh - 1] + 0x53F;
	}

	if (image == 0) image = _road_tile_sprites_1[road != ROAD_NONE ? road : tram];

	roadside = GetRoadside(ti->tile);

	if (AlwaysDrawUnpavedRoads(ti->tile, roadside)) {
		image += 19;
	} else {
		switch (roadside) {
			case ROADSIDE_BARREN:           pal = PALETTE_TO_BARE_LAND; break;
			case ROADSIDE_GRASS:            break;
			case ROADSIDE_GRASS_ROAD_WORKS: break;
			default:                        image -= 19; break; // Paved
		}
	}

	DrawGroundSprite(image, pal);

	/* For tram we overlay the road graphics with either tram tracks only
	 * (when there is actual road beneath the trams) or with tram tracks
	 * and some dirts which hides the road graphics */
	if (tram != ROAD_NONE) {
		if (ti->tileh != SLOPE_FLAT) {
			image = _road_sloped_sprites[ti->tileh - 1] + SPR_TRAMWAY_SLOPED_OFFSET;
		} else {
			image = _road_tile_sprites_1[tram] - SPR_ROAD_Y;
		}
		image += (road == ROAD_NONE) ? SPR_TRAMWAY_TRAM : SPR_TRAMWAY_OVERLAY;
		DrawGroundSprite(image, pal);
	}

	if (road != ROAD_NONE) {
		DisallowedRoadDirections drd = GetDisallowedRoadDirections(ti->tile);
		if (drd != DRD_NONE) {
			DrawRoadDetail(SPR_ONEWAY_BASE + drd - 1 + ((road == ROAD_X) ? 0 : 3), ti, 8, 8, 0);
		}
	}

	if (HasRoadWorks(ti->tile)) {
		/* Road works */
		DrawGroundSprite((road | tram) & ROAD_X ? SPR_EXCAVATION_X : SPR_EXCAVATION_Y, PAL_NONE);
		return;
	}

	if (tram != ROAD_NONE) DrawTramCatenary(ti, tram);

	/* Return if full detail is disabled, or we are zoomed fully out. */
	if (!HasBit(_display_opt, DO_FULL_DETAIL) || _cur_dpi->zoom > ZOOM_LVL_DETAIL) return;

	/* Draw extra details. */
	for (drts = _road_display_table[roadside][road]; drts->image != 0; drts++) {
		DrawRoadDetail(drts->image, ti, drts->subcoord_x, drts->subcoord_y, 0x10);
	}
}

static void DrawTile_Road(TileInfo *ti)
{
	switch (GetRoadTileType(ti->tile)) {
		case ROAD_TILE_NORMAL:
			DrawRoadBits(ti);
			break;

		case ROAD_TILE_CROSSING: {
			SpriteID image;
			SpriteID pal = PAL_NONE;
			Roadside roadside = GetRoadside(ti->tile);

			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			image = GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.crossing;

			if (GetCrossingRoadAxis(ti->tile) == AXIS_X) image++;
			if (IsCrossingBarred(ti->tile)) image += 2;

			if (AlwaysDrawUnpavedRoads(ti->tile, roadside)) {
				image += 8;
			} else {
				switch (roadside) {
					case ROADSIDE_BARREN: pal = PALETTE_TO_BARE_LAND; break;
					case ROADSIDE_GRASS:  break;
					default:              image += 4; break; // Paved
				}
			}

			DrawGroundSprite(image, pal);
			if (HasBit(GetRoadTypes(ti->tile), ROADTYPE_TRAM)) {
				DrawGroundSprite(SPR_TRAMWAY_OVERLAY + (GetCrossingRoadAxis(ti->tile) ^ 1), pal);
				DrawTramCatenary(ti, GetCrossingRoadBits(ti->tile));
			}
			if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
			break;
		}

		default:
		case ROAD_TILE_DEPOT: {
			const DrawTileSprites* dts;
			const DrawTileSeqStruct* dtss;
			SpriteID palette;

			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			palette = PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile));

			if (HasBit(GetRoadTypes(ti->tile), ROADTYPE_TRAM)) {
				dts =  &_tram_depot[GetRoadDepotDirection(ti->tile)];
			} else {
				dts =  &_road_depot[GetRoadDepotDirection(ti->tile)];
			}

			DrawGroundSprite(dts->ground_sprite, PAL_NONE);

			for (dtss = dts->seq; dtss->image != 0; dtss++) {
				SpriteID image = dtss->image;
				SpriteID pal;

				if (!IsTransparencySet(TO_BUILDINGS) && HasBit(image, PALETTE_MODIFIER_COLOR)) {
					pal = palette;
				} else {
					pal = PAL_NONE;
				}

				AddSortableSpriteToDraw(
					image, pal,
					ti->x + dtss->delta_x, ti->y + dtss->delta_y,
					dtss->size_x, dtss->size_y,
					dtss->size_z, ti->z,
					IsTransparencySet(TO_BUILDINGS)
				);
			}
			break;
		}
	}
	DrawBridgeMiddle(ti);
}

void DrawRoadDepotSprite(int x, int y, DiagDirection dir, RoadType rt)
{
	SpriteID palette = PLAYER_SPRITE_COLOR(_local_player);
	const DrawTileSprites* dts = (rt == ROADTYPE_TRAM) ? &_tram_depot[dir] : &_road_depot[dir];
	const DrawTileSeqStruct* dtss;

	x += 33;
	y += 17;

	DrawSprite(dts->ground_sprite, PAL_NONE, x, y);

	for (dtss = dts->seq; dtss->image != 0; dtss++) {
		Point pt = RemapCoords(dtss->delta_x, dtss->delta_y, dtss->delta_z);
		SpriteID image = dtss->image;

		DrawSprite(image, HasBit(image, PALETTE_MODIFIER_COLOR) ? palette : PAL_NONE, x + pt.x, y + pt.y);
	}
}

static uint GetSlopeZ_Road(TileIndex tile, uint x, uint y)
{
	uint z;
	Slope tileh = GetTileSlope(tile, &z);

	if (tileh == SLOPE_FLAT) return z;
	if (GetRoadTileType(tile) == ROAD_TILE_NORMAL) {
		Foundation f = GetRoadFoundation(tileh, GetAllRoadBits(tile));
		z += ApplyFoundationToSlope(f, &tileh);
		return z + GetPartialZ(x & 0xF, y & 0xF, tileh);
	} else {
		return z + TILE_HEIGHT;
	}
}

static Foundation GetFoundation_Road(TileIndex tile, Slope tileh)
{
	if (GetRoadTileType(tile) == ROAD_TILE_NORMAL) {
		return GetRoadFoundation(tileh, GetAllRoadBits(tile));
	} else {
		return FlatteningFoundation(tileh);
	}
}

static void GetAcceptedCargo_Road(TileIndex tile, AcceptedCargo ac)
{
	/* not used */
}

static void AnimateTile_Road(TileIndex tile)
{
	if (IsLevelCrossing(tile)) MarkTileDirtyByTile(tile);
}


static const Roadside _town_road_types[][2] = {
	{ ROADSIDE_GRASS,         ROADSIDE_GRASS },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_TREES,         ROADSIDE_TREES },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
};

static const Roadside _town_road_types_2[][2] = {
	{ ROADSIDE_GRASS,         ROADSIDE_GRASS },
	{ ROADSIDE_PAVED,         ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED },
	{ ROADSIDE_STREET_LIGHTS, ROADSIDE_PAVED }
};


static void TileLoop_Road(TileIndex tile)
{
	switch (_opt.landscape) {
		case LT_ARCTIC:
			if (IsOnSnow(tile) != (GetTileZ(tile) > GetSnowLine())) {
				ToggleSnow(tile);
				MarkTileDirtyByTile(tile);
			}
			break;

		case LT_TROPIC:
			if (GetTropicZone(tile) == TROPICZONE_DESERT && !IsOnDesert(tile)) {
				ToggleDesert(tile);
				MarkTileDirtyByTile(tile);
			}
			break;
	}

	if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) return;

	const Town* t = ClosestTownFromTile(tile, (uint)-1);
	if (!HasRoadWorks(tile)) {
		int grp = 0;

		if (t != NULL) {
			grp = GetTownRadiusGroup(t, tile);

			/* Show an animation to indicate road work */
			if (t->road_build_months != 0 &&
					(DistanceManhattan(t->xy, tile) < 8 || grp != 0) &&
					GetRoadTileType(tile) == ROAD_TILE_NORMAL && CountBits(GetAllRoadBits(tile)) > 1 ) {
				if (GetTileSlope(tile, NULL) == SLOPE_FLAT && EnsureNoVehicleOnGround(tile) && Chance16(1, 40)) {
					StartRoadWorks(tile);

					SndPlayTileFx(SND_21_JACKHAMMER, tile);
					CreateEffectVehicleAbove(
						TileX(tile) * TILE_SIZE + 7,
						TileY(tile) * TILE_SIZE + 7,
						0,
						EV_BULLDOZER);
					MarkTileDirtyByTile(tile);
					return;
				}
			}
		}

		{
			/* Adjust road ground type depending on 'grp' (grp is the distance to the center) */
			const Roadside* new_rs = (_opt.landscape == LT_TOYLAND) ? _town_road_types_2[grp] : _town_road_types[grp];
			Roadside cur_rs = GetRoadside(tile);

			/* We have our desired type, do nothing */
			if (cur_rs == new_rs[0]) return;

			/* We have the pre-type of the desired type, switch to the desired type */
			if (cur_rs == new_rs[1]) {
				cur_rs = new_rs[0];
			/* We have barren land, install the pre-type */
			} else if (cur_rs == ROADSIDE_BARREN) {
				cur_rs = new_rs[1];
			/* We're totally off limits, remove any installation and make barren land */
			} else {
				cur_rs = ROADSIDE_BARREN;
			}
			SetRoadside(tile, cur_rs);
			MarkTileDirtyByTile(tile);
		}
	} else if (IncreaseRoadWorksCounter(tile)) {
		TerminateRoadWorks(tile);

		if (_patches.mod_road_rebuild) {
			/* Generate a nicer town surface */
			const RoadBits old_rb = GetAnyRoadBits(tile, ROADTYPE_ROAD);
			const RoadBits new_rb = CleanUpRoadBits(tile, old_rb);

			if (old_rb != new_rb) {
				DoCommand(tile, (old_rb ^ new_rb), t->index, DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_REMOVE_ROAD);
			}
		}

		MarkTileDirtyByTile(tile);
	}
}

static void ClickTile_Road(TileIndex tile)
{
	if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) ShowDepotWindow(tile, VEH_ROAD);
}

static const byte _road_trackbits[16] = {
	0x0, 0x0, 0x0, 0x10, 0x0, 0x2, 0x8, 0x1A, 0x0, 0x4, 0x1, 0x15, 0x20, 0x26, 0x29, 0x3F,
};

static uint32 GetTileTrackStatus_Road(TileIndex tile, TransportType mode, uint sub_mode)
{

	switch (mode) {
		case TRANSPORT_RAIL:
			if (!IsLevelCrossing(tile)) return 0;
			return GetCrossingRailBits(tile) * 0x101;

		case TRANSPORT_ROAD:
			if ((GetRoadTypes(tile) & sub_mode) == 0) return 0;
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					RoadType rt = (RoadType)FindFirstBit(sub_mode);
					const uint drd_to_multiplier[DRD_END] = { 0x101, 0x100, 0x1, 0x0 };
					uint multiplier = drd_to_multiplier[rt == ROADTYPE_TRAM ? DRD_NONE : GetDisallowedRoadDirections(tile)];
					return HasRoadWorks(tile) ? 0 : _road_trackbits[GetRoadBits(tile, rt)] * multiplier;
				}

				case ROAD_TILE_CROSSING: {
					uint32 r = AxisToTrackBits(GetCrossingRoadAxis(tile)) * 0x101;

					if (IsCrossingBarred(tile)) r *= 0x10001;
					return r;
				}

				default:
				case ROAD_TILE_DEPOT:
					return AxisToTrackBits(DiagDirToAxis(GetRoadDepotDirection(tile))) * 0x101;
			}
			break;

		default: break;
	}
	return 0;
}

static const StringID _road_tile_strings[] = {
	STR_1814_ROAD,
	STR_1814_ROAD,
	STR_1814_ROAD,
	STR_1815_ROAD_WITH_STREETLIGHTS,
	STR_1814_ROAD,
	STR_1816_TREE_LINED_ROAD,
	STR_1814_ROAD,
	STR_1814_ROAD,
};

static void GetTileDesc_Road(TileIndex tile, TileDesc *td)
{
	td->owner = GetTileOwner(tile);
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_CROSSING: td->str = STR_1818_ROAD_RAIL_LEVEL_CROSSING; break;
		case ROAD_TILE_DEPOT: td->str = STR_1817_ROAD_VEHICLE_DEPOT; break;
		default: td->str = _road_tile_strings[GetRoadside(tile)]; break;
	}
}

/**
 * Given the direction the road depot is pointing, this is the direction the
 * vehicle should be travelling in in order to enter the depot.
 */
static const byte _roadveh_enter_depot_dir[4] = {
	TRACKDIR_X_SW, TRACKDIR_Y_NW, TRACKDIR_X_NE, TRACKDIR_Y_SE
};

static uint32 VehicleEnter_Road(Vehicle *v, TileIndex tile, int x, int y)
{
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_CROSSING:
			if (v->type == VEH_TRAIN && !IsCrossingBarred(tile)) {
				/* train crossing a road */
				SndPlayVehicleFx(SND_0E_LEVEL_CROSSING, v);
				BarCrossing(tile);
				MarkTileDirtyByTile(tile);
			}
			break;

		case ROAD_TILE_DEPOT:
			if (v->type == VEH_ROAD &&
					v->u.road.frame == 11 &&
					_roadveh_enter_depot_dir[GetRoadDepotDirection(tile)] == v->u.road.state) {
				v->u.road.state = RVSB_IN_DEPOT;
				v->vehstatus |= VS_HIDDEN;
				v->direction = ReverseDir(v->direction);
				if (v->Next() == NULL) VehicleEnterDepot(v);
				v->tile = tile;

				InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
				return VETSB_ENTERED_WORMHOLE;
			}
			break;

		default: break;
	}
	return VETSB_CONTINUE;
}


static void ChangeTileOwner_Road(TileIndex tile, PlayerID old_player, PlayerID new_player)
{
	if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) {
		if (GetTileOwner(tile) == old_player) {
			if (new_player == PLAYER_SPECTATOR) {
				DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
			} else {
				SetTileOwner(tile, new_player);
			}
		}
		return;
	}

	for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
		if (!HasBit(GetRoadTypes(tile), rt)) continue;

		if (GetRoadOwner(tile, rt) == old_player) {
			SetRoadOwner(tile, rt, new_player == PLAYER_SPECTATOR ? OWNER_NONE : new_player);
		}
	}

	if (IsLevelCrossing(tile)) {
		if (GetTileOwner(tile) == old_player) {
			if (new_player == PLAYER_SPECTATOR) {
				MakeRoadNormal(tile, GetCrossingRoadBits(tile), GetRoadTypes(tile), GetTownIndex(tile), GetRoadOwner(tile, ROADTYPE_ROAD), GetRoadOwner(tile, ROADTYPE_TRAM), GetRoadOwner(tile, ROADTYPE_HWAY));
			} else {
				SetTileOwner(tile, new_player);
			}
		}
	}
}

static CommandCost TerraformTile_Road(TileIndex tile, uint32 flags, uint z_new, Slope tileh_new)
{
	if (_patches.build_on_slopes && AutoslopeEnabled()) {
		switch (GetRoadTileType(tile)) {
			case ROAD_TILE_CROSSING:
				if (!IsSteepSlope(tileh_new) && (GetTileMaxZ(tile) == z_new + GetSlopeMaxZ(tileh_new)) && HasBit(VALID_LEVEL_CROSSING_SLOPES, tileh_new)) return _price.terraform;
				break;

			case ROAD_TILE_DEPOT:
				if (AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRoadDepotDirection(tile))) return _price.terraform;
				break;

			case ROAD_TILE_NORMAL: {
				RoadBits bits = GetAllRoadBits(tile);
				RoadBits bits_copy = bits;
				/* Check if the slope-road_bits combination is valid at all, i.e. it is save to call GetRoadFoundation(). */
				if (!CmdFailed(CheckRoadSlope(tileh_new, &bits_copy, ROAD_NONE))) {
					/* CheckRoadSlope() sometimes changes the road_bits, if it does not agree with them. */
					if (bits == bits_copy) {
						uint z_old;
						Slope tileh_old = GetTileSlope(tile, &z_old);

						/* Get the slope on top of the foundation */
						z_old += ApplyFoundationToSlope(GetRoadFoundation(tileh_old, bits), &tileh_old);
						z_new += ApplyFoundationToSlope(GetRoadFoundation(tileh_new, bits), &tileh_new);

						/* The surface slope must not be changed */
						if ((z_old == z_new) && (tileh_old == tileh_new)) return _price.terraform;
					}
				}
				break;
			}

			default: NOT_REACHED();
		}
	}

	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
}


extern const TileTypeProcs _tile_type_road_procs = {
	DrawTile_Road,           /* draw_tile_proc */
	GetSlopeZ_Road,          /* get_slope_z_proc */
	ClearTile_Road,          /* clear_tile_proc */
	GetAcceptedCargo_Road,   /* get_accepted_cargo_proc */
	GetTileDesc_Road,        /* get_tile_desc_proc */
	GetTileTrackStatus_Road, /* get_tile_track_status_proc */
	ClickTile_Road,          /* click_tile_proc */
	AnimateTile_Road,        /* animate_tile_proc */
	TileLoop_Road,           /* tile_loop_clear */
	ChangeTileOwner_Road,    /* change_tile_owner_clear */
	NULL,                    /* get_produced_cargo_proc */
	VehicleEnter_Road,       /* vehicle_enter_tile_proc */
	GetFoundation_Road,      /* get_foundation_proc */
	TerraformTile_Road,      /* terraform_tile_proc */
};