summaryrefslogtreecommitdiff
path: root/src/road_cmd.cpp
blob: 5fc871bfb7afa6cdd5be9c37a506761bad7c8433 (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
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file road_cmd.cpp Commands related to road tiles. */

#include "stdafx.h"
#include "cmd_helper.h"
#include "road_internal.h"
#include "viewport_func.h"
#include "command_func.h"
#include "pathfinder/yapf/yapf_cache.h"
#include "depot_base.h"
#include "newgrf.h"
#include "autoslope.h"
#include "tunnelbridge_map.h"
#include "window_func.h"
#include "strings_func.h"
#include "vehicle_func.h"
#include "sound_func.h"
#include "tunnelbridge.h"
#include "cheat_type.h"
#include "effectvehicle_func.h"
#include "effectvehicle_base.h"
#include "elrail_func.h"
#include "roadveh.h"
#include "town.h"
#include "company_base.h"
#include "core/random_func.hpp"
#include "newgrf_railtype.h"
#include "date_func.h"
#include "genworld.h"

#include "table/strings.h"

/**
 * Verify whether a road vehicle is available.
 * @return \c true if at least one road vehicle is available, \c false if not
 */
bool RoadVehiclesAreBuilt()
{
	const RoadVehicle *rv;
	FOR_ALL_ROADVEHICLES(rv) return true;

	return false;
}

/** Invalid RoadBits on slopes.  */
static const RoadBits _invalid_tileh_slopes_road[2][15] = {
	/* The inverse of the mixable RoadBits on a leveled slope */
	{
		ROAD_NONE,         // 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_NONE,         // SLOPE_EW

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

		ROAD_SE,           // SLOPE_NW
		ROAD_NONE,         // SLOPE_NS
		ROAD_NONE,         // SLOPE_ENW

		ROAD_SW,           // SLOPE_NE
		ROAD_NONE,         // SLOPE_SEN
		ROAD_NONE          // SLOPE_NWS
	},
	/* The inverse of the allowed straight roads on a slope
	 * (with and without a foundation). */
	{
		ROAD_NONE, // SLOPE_FLAT
		ROAD_NONE, // SLOPE_W    Foundation
		ROAD_NONE, // SLOPE_S    Foundation

		ROAD_Y,    // SLOPE_SW
		ROAD_NONE, // SLOPE_E    Foundation
		ROAD_ALL,  // SLOPE_EW

		ROAD_X,    // SLOPE_SE
		ROAD_ALL,  // SLOPE_WSE
		ROAD_NONE, // SLOPE_N    Foundation

		ROAD_X,    // SLOPE_NW
		ROAD_ALL,  // SLOPE_NS
		ROAD_ALL,  // SLOPE_ENW

		ROAD_Y,    // SLOPE_NE
		ROAD_ALL,  // SLOPE_SEN
		ROAD_ALL   // SLOPE_NW
	}
};

static Foundation GetRoadFoundation(Slope tileh, RoadBits bits);

/**
 * Is it allowed to remove the given road bits from the given tile?
 * @param tile      the tile to remove the road from
 * @param remove    the roadbits that are going to be removed
 * @param owner     the actual owner of the roadbits of the tile
 * @param rt        the road type to remove the bits from
 * @param flags     command flags
 * @param town_check Shall the town rating checked/affected
 * @return A succeeded command when it is allowed to remove the road bits, a failed command otherwise.
 */
CommandCost CheckAllowRemoveRoad(TileIndex tile, RoadBits remove, Owner owner, RoadType rt, DoCommandFlag flags, bool town_check)
{
	if (_game_mode == GM_EDITOR || remove == ROAD_NONE) return CommandCost();

	/* 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_company == OWNER_WATER ||
			(rt == ROADTYPE_ROAD && !Company::IsValidID(_current_company))) return CommandCost();

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

	if (!town_check) return CommandCost();

	if (_cheats.magic_bulldozer.value) return CommandCost();

	Town *t = ClosestTownFromTile(tile, UINT_MAX);
	if (t == NULL) return CommandCost();

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

	/* Get a bitmask of which neighbouring roads has a tile */
	RoadBits n = ROAD_NONE;
	RoadBits 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;

	int rating_decrease = RATING_ROAD_DOWN_STEP_EDGE;
	/* If 0 or 1 bits are set in n, or if no bits that match the bits to remove,
	 * then allow it */
	if (KillFirstBit(n) != ROAD_NONE && (n & remove) != ROAD_NONE) {
		/* you can remove all kind of roads with extra dynamite */
		if (!_settings_game.construction.extra_dynamite) {
			SetDParam(0, t->index);
			return_cmd_error(STR_ERROR_LOCAL_AUTHORITY_REFUSES_TO_ALLOW_THIS);
		}
		rating_decrease = RATING_ROAD_DOWN_STEP_INNER;
	}
	ChangeTownRating(t, rating_decrease, RATING_ROAD_MINIMUM, flags);

	return CommandCost();
}


/**
 * Delete a piece of road.
 * @param tile tile where to remove road from
 * @param flags operation to perform
 * @param pieces roadbits to remove
 * @param rt roadtype to remove
 * @param crossing_check should we check if there is a tram track when we are removing road from crossing?
 * @param town_check should we check if the town allows removal?
 */
static CommandCost RemoveRoad(TileIndex tile, DoCommandFlag flags, RoadBits pieces, RoadType rt, bool crossing_check, bool town_check = true)
{
	RoadTypes rts = GetRoadTypes(tile);
	/* The tile doesn't have the given road type */
	if (!HasBit(rts, rt)) return_cmd_error(rt == ROADTYPE_TRAM ? STR_ERROR_THERE_IS_NO_TRAMWAY : STR_ERROR_THERE_IS_NO_ROAD);

	switch (GetTileType(tile)) {
		case MP_ROAD: {
			CommandCost ret = EnsureNoVehicleOnGround(tile);
			if (ret.Failed()) return ret;
			break;
		}

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

			CommandCost ret = EnsureNoVehicleOnGround(tile);
			if (ret.Failed()) return ret;
			break;
		}

		case MP_TUNNELBRIDGE: {
			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
			CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile));
			if (ret.Failed()) return ret;
			break;
		}

		default:
			return CMD_ERROR;
	}

	CommandCost ret = CheckAllowRemoveRoad(tile, pieces, GetRoadOwner(tile, rt), rt, flags, town_check);
	if (ret.Failed()) return ret;

	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(EXPENSES_CONSTRUCTION);
		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
			TileIndex other_end = GetOtherTunnelBridgeEnd(tile);
			/* Pay for *every* tile of the bridge or tunnel */
			cost.AddCost((GetTunnelBridgeLength(other_end, tile) + 2) * _price[PR_CLEAR_ROAD]);
			if (flags & DC_EXEC) {
				SetRoadTypes(other_end, GetRoadTypes(other_end) & ~RoadTypeToRoadTypes(rt));
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));

				/* If the owner of the bridge sells all its road, also move the ownership
				 * to the owner of the other roadtype. */
				RoadType other_rt = (rt == ROADTYPE_ROAD) ? ROADTYPE_TRAM : ROADTYPE_ROAD;
				Owner other_owner = GetRoadOwner(tile, other_rt);
				if (other_owner != GetTileOwner(tile)) {
					SetTileOwner(tile, other_owner);
					SetTileOwner(other_end, other_owner);
				}

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

					for (TileIndex t = tile + delta; t != other_end; t += delta) MarkTileDirtyByTile(t);
				}
			}
		} else {
			assert(IsDriveThroughStopTile(tile));
			cost.AddCost(_price[PR_CLEAR_ROAD] * 2);
			if (flags & DC_EXEC) {
				SetRoadTypes(tile, GetRoadTypes(tile) & ~RoadTypeToRoadTypes(rt));
				MarkTileDirtyByTile(tile);
			}
		}
		return cost;
	}

	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_NORMAL: {
			Slope tileh = GetTileSlope(tile);

			/* Steep slopes behave the same as slopes with one corner raised. */
			if (IsSteepSlope(tileh)) {
				tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
			}

			RoadBits present = GetRoadBits(tile, rt);
			const RoadBits other = GetOtherRoadBits(tile, rt);
			const Foundation f = GetRoadFoundation(tileh, present);

			if (HasRoadWorks(tile) && _current_company != OWNER_WATER) return_cmd_error(STR_ERROR_ROAD_WORKS_IN_PROGRESS);

			/* Autocomplete to a straight road
			 * @li if the bits of the other roadtypes result in another foundation
			 * @li if build on slopes is disabled */
			if ((IsStraightRoad(other) && (other & _invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED]) != ROAD_NONE) ||
					(tileh != SLOPE_FLAT && !_settings_game.construction.build_on_slopes)) {
				pieces |= MirrorRoadBits(pieces);
			}

			/* limit the bits to delete to the existing bits. */
			pieces &= present;
			if (pieces == ROAD_NONE) return_cmd_error(rt == ROADTYPE_TRAM ? STR_ERROR_THERE_IS_NO_TRAMWAY : STR_ERROR_THERE_IS_NO_ROAD);

			/* Now set present what it will be after the remove */
			present ^= pieces;

			/* Check for invalid RoadBit combinations on slopes */
			if (tileh != SLOPE_FLAT && present != ROAD_NONE &&
					(present & _invalid_tileh_slopes_road[0][tileh & SLOPE_ELEVATED]) == present) {
				return CMD_ERROR;
			}

			if (flags & DC_EXEC) {
				if (HasRoadWorks(tile)) {
					/* flooding tile with road works, don't forget to remove the effect vehicle too */
					assert(_current_company == OWNER_WATER);
					EffectVehicle *v;
					FOR_ALL_EFFECTVEHICLES(v) {
						if (TileVirtXY(v->x_pos, v->y_pos) == tile) {
							delete v;
						}
					}
				}
				if (present == ROAD_NONE) {
					RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
					if (rts == ROADTYPES_NONE) {
						/* Includes MarkTileDirtyByTile() */
						DoClearSquare(tile);
					} else {
						if (rt == ROADTYPE_ROAD && IsRoadOwner(tile, ROADTYPE_ROAD, OWNER_TOWN)) {
							/* Update nearest-town index */
							const Town *town = CalcClosestTownFromTile(tile);
							SetTownIndex(tile, town == NULL ? (TownID)INVALID_TOWN : town->index);
						}
						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);
				}
			}

			CommandCost cost(EXPENSES_CONSTRUCTION, CountBits(pieces) * _price[PR_CLEAR_ROAD]);
			/* If we build a foundation we have to pay for it. */
			if (f == FOUNDATION_NONE && GetRoadFoundation(tileh, present) != FOUNDATION_NONE) cost.AddCost(_price[PR_BUILD_FOUNDATION]);

			return cost;
		}

		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 roadbits ;) */
			if (rt == ROADTYPE_ROAD && HasTileRoadType(tile, ROADTYPE_TRAM) && (flags & DC_EXEC || crossing_check)) return CMD_ERROR;

			if (flags & DC_EXEC) {
				Track railtrack = GetCrossingRailTrack(tile);
				RoadTypes rts = GetRoadTypes(tile) & ComplementRoadTypes(RoadTypeToRoadTypes(rt));
				if (rts == ROADTYPES_NONE) {
					TrackBits tracks = GetCrossingRailBits(tile);
					bool reserved = HasCrossingReservation(tile);
					MakeRailNormal(tile, GetTileOwner(tile), tracks, GetRailType(tile));
					if (reserved) SetTrackReservation(tile, tracks);
				} else {
					SetRoadTypes(tile, rts);
					/* If we ever get HWAY and it is possible without road then we will need to promote ownership and invalidate town index here, too */
				}
				MarkTileDirtyByTile(tile);
				YapfNotifyTrackLayoutChange(tile, railtrack);
			}
			return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_ROAD] * 2);
		}

		default:
		case ROAD_TILE_DEPOT:
			return CMD_ERROR;
	}
}


/**
 * 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 of the current type
 * @param other The other existent RoadBits
 * @return The costs for these RoadBits on this slope
 */
static CommandCost CheckRoadSlope(Slope tileh, RoadBits *pieces, RoadBits existing, RoadBits other)
{
	/* Remove already build pieces */
	CLRBITS(*pieces, existing);

	/* If we can't build anything stop here */
	if (*pieces == ROAD_NONE) return CMD_ERROR;

	/* All RoadBit combos are valid on flat land */
	if (tileh == SLOPE_FLAT) return CommandCost();

	/* Steep slopes behave the same as slopes with one corner raised. */
	if (IsSteepSlope(tileh)) {
		tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
	}

	/* Save the merge of all bits of the current type */
	RoadBits type_bits = existing | *pieces;

	/* Roads on slopes */
	if (_settings_game.construction.build_on_slopes && (_invalid_tileh_slopes_road[0][tileh] & (other | type_bits)) == ROAD_NONE) {

		/* If we add leveling we've got to pay for it */
		if ((other | existing) == ROAD_NONE) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);

		return CommandCost();
	}

	/* Autocomplete uphill roads */
	*pieces |= MirrorRoadBits(*pieces);
	type_bits = existing | *pieces;

	/* Uphill roads */
	if (IsStraightRoad(type_bits) && (other == type_bits || other == ROAD_NONE) &&
			(_invalid_tileh_slopes_road[1][tileh] & (other | type_bits)) == ROAD_NONE) {

		/* Slopes with foundation ? */
		if (IsSlopeWithOneCornerRaised(tileh)) {

			/* Prevent build on slopes if it isn't allowed */
			if (_settings_game.construction.build_on_slopes) {

				/* If we add foundation we've got to pay for it */
				if ((other | existing) == ROAD_NONE) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);

				return CommandCost();
			}
		} else {
			if (HasExactlyOneBit(existing) && GetRoadFoundation(tileh, existing) == FOUNDATION_NONE) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
			return CommandCost();
		}
	}
	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)
 * @param text unused
 * @return the cost of this operation or an error
 */
CommandCost CmdBuildRoad(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);

	RoadBits existing = ROAD_NONE;
	RoadBits other_bits = ROAD_NONE;

	/* Road pieces are max 4 bitset values (NE, NW, SE, SW) and town can only be non-zero
	 * if a non-company is building the road */
	if ((Company::IsValidID(_current_company) && p2 != 0) || (_current_company == OWNER_TOWN && !Town::IsValidID(p2))) return CMD_ERROR;
	if (_current_company != OWNER_TOWN) {
		const Town *town = CalcClosestTownFromTile(tile);
		p2 = (town != NULL) ? town->index : (TownID)INVALID_TOWN;
	}

	RoadBits pieces = Extract<RoadBits, 0, 4>(p1);

	/* do not allow building 'zero' road bits, code wouldn't handle it */
	if (pieces == ROAD_NONE) return CMD_ERROR;

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

	DisallowedRoadDirections toggle_drd = Extract<DisallowedRoadDirections, 6, 2>(p1);

	Slope tileh = GetTileSlope(tile);

	bool need_to_clear = false;
	switch (GetTileType(tile)) {
		case MP_ROAD:
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					if (HasRoadWorks(tile)) return_cmd_error(STR_ERROR_ROAD_WORKS_IN_PROGRESS);

					other_bits = GetOtherRoadBits(tile, rt);
					if (!HasTileRoadType(tile, rt)) break;

					existing = GetRoadBits(tile, rt);
					bool crossing = !IsStraightRoad(existing | pieces);
					if (rt != ROADTYPE_TRAM && (GetDisallowedRoadDirections(tile) != DRD_NONE || toggle_drd != DRD_NONE) && crossing) {
						/* Junctions cannot be one-way */
						return_cmd_error(STR_ERROR_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) {
							if (crossing) return_cmd_error(STR_ERROR_ONEWAY_ROADS_CAN_T_HAVE_JUNCTION);

							Owner owner = GetRoadOwner(tile, ROADTYPE_ROAD);
							if (owner != OWNER_NONE) {
								CommandCost ret = CheckOwnership(owner, tile);
								if (ret.Failed()) return ret;
							}

							DisallowedRoadDirections dis_existing = GetDisallowedRoadDirections(tile);
							DisallowedRoadDirections dis_new      = dis_existing ^ toggle_drd;

							/* We allow removing disallowed directions to break up
							 * deadlocks, but adding them can break articulated
							 * vehicles. As such, only when less is disallowed,
							 * i.e. bits are removed, we skip the vehicle check. */
							if (CountBits(dis_existing) <= CountBits(dis_new)) {
								CommandCost ret = EnsureNoVehicleOnGround(tile);
								if (ret.Failed()) return ret;
							}

							/* Ignore half built tiles */
							if ((flags & DC_EXEC) && rt != ROADTYPE_TRAM && IsStraightRoad(existing)) {
								SetDisallowedRoadDirections(tile, dis_new);
								MarkTileDirtyByTile(tile);
							}
							return CommandCost();
						}
						return_cmd_error(STR_ERROR_ALREADY_BUILT);
					}
					break;
				}

				case ROAD_TILE_CROSSING:
					other_bits = GetCrossingRoadBits(tile);
					if (pieces & ComplementRoadBits(other_bits)) goto do_clear;
					pieces = other_bits; // we need to pay for both roadbits

					if (HasTileRoadType(tile, rt)) return_cmd_error(STR_ERROR_ALREADY_BUILT);
					break;

				case ROAD_TILE_DEPOT:
					if ((GetAnyRoadBits(tile, rt) & pieces) == pieces) return_cmd_error(STR_ERROR_ALREADY_BUILT);
					goto do_clear;

				default: NOT_REACHED();
			}
			break;

		case MP_RAILWAY: {
			if (IsSteepSlope(tileh)) {
				return_cmd_error(STR_ERROR_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_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
			}

			if (GetRailTileType(tile) != RAIL_TILE_NORMAL) goto do_clear;

			if (RailNoLevelCrossings(GetRailType(tile))) {
				return_cmd_error(STR_ERROR_CROSSING_DISALLOWED);
			}

			Axis roaddir;
			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;
			}

			CommandCost ret = EnsureNoVehicleOnGround(tile);
			if (ret.Failed()) return ret;

			if (flags & DC_EXEC) {
				Track railtrack = AxisToTrack(OtherAxis(roaddir));
				YapfNotifyTrackLayoutChange(tile, railtrack);
				/* Always add road to the roadtypes (can't draw without it) */
				bool reserved = HasBit(GetRailReservationTrackBits(tile), railtrack);
				MakeRoadCrossing(tile, _current_company, _current_company, GetTileOwner(tile), roaddir, GetRailType(tile), RoadTypeToRoadTypes(rt) | ROADTYPES_ROAD, p2);
				SetCrossingReservation(tile, reserved);
				UpdateLevelCrossing(tile, false);
				MarkTileDirtyByTile(tile);
			}
			return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_ROAD] * (rt == ROADTYPE_ROAD ? 2 : 4));
		}

		case MP_STATION: {
			if ((GetAnyRoadBits(tile, rt) & pieces) == pieces) return_cmd_error(STR_ERROR_ALREADY_BUILT);
			if (!IsDriveThroughStopTile(tile)) goto do_clear;

			RoadBits curbits = AxisToRoadBits(DiagDirToAxis(GetRoadStopDir(tile)));
			if (pieces & ~curbits) goto do_clear;
			pieces = curbits; // we need to pay for both roadbits

			if (HasTileRoadType(tile, rt)) return_cmd_error(STR_ERROR_ALREADY_BUILT);
			break;
		}

		case MP_TUNNELBRIDGE: {
			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) goto do_clear;
			if (MirrorRoadBits(DiagDirToRoadBits(GetTunnelBridgeDirection(tile))) != pieces) goto do_clear;
			if (HasTileRoadType(tile, rt)) return_cmd_error(STR_ERROR_ALREADY_BUILT);
			/* Don't allow adding roadtype to the bridge/tunnel when vehicles are already driving on it */
			CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile));
			if (ret.Failed()) return ret;
			break;
		}

		default: {
do_clear:;
			need_to_clear = true;
			break;
		}
	}

	if (need_to_clear) {
		CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
		if (ret.Failed()) return ret;
		cost.AddCost(ret);
	}

	if (other_bits != pieces) {
		/* Check the foundation/slopes when adding road/tram bits */
		CommandCost ret = CheckRoadSlope(tileh, &pieces, existing, other_bits);
		/* Return an error if we need to build a foundation (ret != 0) but the
		 * current setting is turned off */
		if (ret.Failed() || (ret.GetCost() != 0 && !_settings_game.construction.build_on_slopes)) {
			return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
		}
		cost.AddCost(ret);
	}

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

			/* Check if new road bits will have the same foundation as other existing road types */
			if (IsNormalRoad(tile)) {
				Slope slope = GetTileSlope(tile);
				Foundation found_new = GetRoadFoundation(slope, pieces | existing);

				/* Test if all other roadtypes can be built at that foundation */
				for (RoadType rtest = ROADTYPE_ROAD; rtest < ROADTYPE_END; rtest++) {
					if (rtest != rt) { // check only other road types
						RoadBits bits = GetRoadBits(tile, rtest);
						/* do not check if there are not road bits of given type */
						if (bits != ROAD_NONE && GetRoadFoundation(slope, bits) != found_new) {
							return_cmd_error(STR_ERROR_LAND_SLOPED_IN_WRONG_DIRECTION);
						}
					}
				}
			}
		}

		CommandCost ret = EnsureNoVehicleOnGround(tile);
		if (ret.Failed()) return ret;

	}

	uint num_pieces = (!need_to_clear && IsTileType(tile, MP_TUNNELBRIDGE)) ?
			/* There are 2 pieces on *every* tile of the bridge or tunnel */
			2 * (GetTunnelBridgeLength(GetOtherTunnelBridgeEnd(tile), tile) + 2) :
			/* Count pieces */
			CountBits(pieces);

	cost.AddCost(num_pieces * _price[PR_BUILD_ROAD]);

	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_company);
					if (rt == ROADTYPE_ROAD) SetTownIndex(tile, p2);
				}
				if (rtt != ROAD_TILE_CROSSING) SetRoadBits(tile, existing | pieces, rt);
				break;
			}

			case MP_TUNNELBRIDGE: {
				TileIndex other_end = GetOtherTunnelBridgeEnd(tile);

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

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

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

			case MP_STATION:
				assert(IsDriveThroughStopTile(tile));
				SetRoadTypes(tile, GetRoadTypes(tile) | RoadTypeToRoadTypes(rt));
				SetRoadOwner(tile, rt, _current_company);
				break;

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

		if (rt != ROADTYPE_TRAM && IsNormalRoadTile(tile)) {
			existing |= pieces;
			SetDisallowedRoadDirections(tile, IsStraightRoad(existing) ?
					GetDisallowedRoadDirections(tile) ^ toggle_drd : DRD_NONE);
		}

		MarkTileDirtyByTile(tile);
	}
	return cost;
}

/**
 * Build a long piece of road.
 * @param start_tile start tile of drag (the building cost will appear over this tile)
 * @param flags operation to perform
 * @param p1 end 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
 * - p2 = (bit 6) - 0 = build up to an obstacle, 1 = fail if an obstacle is found (used for AIs).
 * @param text unused
 * @return the cost of this operation or an error
 */
CommandCost CmdBuildLongRoad(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
	DisallowedRoadDirections drd = DRD_NORTHBOUND;

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

	TileIndex end_tile = p1;
	RoadType rt = Extract<RoadType, 3, 2>(p2);
	if (!IsValidRoadType(rt) || !ValParamRoadType(rt)) return CMD_ERROR;

	Axis axis = Extract<Axis, 2, 1>(p2);
	/* Only drag in X or Y direction dictated by the direction variable */
	if (axis == AXIS_X && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (axis == AXIS_Y && TileX(start_tile) != TileX(end_tile)) return CMD_ERROR; // y-axis

	DiagDirection dir = AxisToDiagDir(axis);

	/* Swap direction, also the half-tile drag var (bit 0 and 1) */
	if (start_tile > end_tile || (start_tile == end_tile && HasBit(p2, 0))) {
		dir = ReverseDiagDir(dir);
		p2 ^= 3;
		drd = DRD_SOUTHBOUND;
	}

	/* On the X-axis, we have to swap the initial bits, so they
	 * will be interpreted correctly in the GTTS. Furthermore
	 * when you just 'click' on one tile to build them. */
	if ((axis == AXIS_Y) == (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;

	CommandCost cost(EXPENSES_CONSTRUCTION);
	CommandCost last_error = CMD_ERROR;
	TileIndex tile = start_tile;
	bool had_bridge = false;
	bool had_tunnel = false;
	bool had_success = false;
	/* Start tile is the first tile clicked by the user. */
	for (;;) {
		RoadBits bits = AxisToRoadBits(axis);

		/* Road parts only have to be built at the start tile or at the end tile. */
		if (tile == end_tile && !HasBit(p2, 1)) bits &= DiagDirToRoadBits(ReverseDiagDir(dir));
		if (tile == start_tile && HasBit(p2, 0)) bits &= DiagDirToRoadBits(dir);

		CommandCost ret = DoCommand(tile, drd << 6 | rt << 4 | bits, 0, flags, CMD_BUILD_ROAD);
		if (ret.Failed()) {
			last_error = ret;
			if (last_error.GetErrorMessage() != STR_ERROR_ALREADY_BUILT) {
				if (HasBit(p2, 6)) return last_error;
				break;
			}
		} 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 || GetTunnelBridgeDirection(tile) == dir) {
						cost.AddCost(ret);
					}
					had_bridge = true;
				} else { // IsTunnel(tile)
					if (!had_tunnel || GetTunnelBridgeDirection(tile) == dir) {
						cost.AddCost(ret);
					}
					had_tunnel = true;
				}
			} else {
				cost.AddCost(ret);
			}
		}

		if (tile == end_tile) break;

		tile += TileOffsByDiagDir(dir);
	}

	return had_success ? cost : last_error;
}

/**
 * Remove a long piece of road.
 * @param start_tile start tile of drag
 * @param flags operation to perform
 * @param p1 end 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
 * @param text unused
 * @return the cost of this operation or an error
 */
CommandCost CmdRemoveLongRoad(TileIndex start_tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
	CommandCost cost(EXPENSES_CONSTRUCTION);

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

	TileIndex end_tile = p1;
	RoadType rt = Extract<RoadType, 3, 2>(p2);
	if (!IsValidRoadType(rt)) return CMD_ERROR;

	Axis axis = Extract<Axis, 2, 1>(p2);
	/* Only drag in X or Y direction dictated by the direction variable */
	if (axis == AXIS_X && TileY(start_tile) != TileY(end_tile)) return CMD_ERROR; // x-axis
	if (axis == AXIS_Y && 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 money = GetAvailableMoneyForCommand();
	TileIndex tile = start_tile;
	CommandCost last_error = CMD_ERROR;
	bool had_success = false;
	/* Start tile is the small number. */
	for (;;) {
		RoadBits bits = AxisToRoadBits(axis);

		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) {
			CommandCost ret = RemoveRoad(tile, flags & ~DC_EXEC, bits, rt, true);
			if (ret.Succeeded()) {
				if (flags & DC_EXEC) {
					money -= ret.GetCost();
					if (money < 0) {
						_additional_cash_required = DoCommand(start_tile, end_tile, p2, flags & ~DC_EXEC, CMD_REMOVE_LONG_ROAD).GetCost();
						return cost;
					}
					RemoveRoad(tile, flags, bits, rt, true, false);
				}
				cost.AddCost(ret);
				had_success = true;
			} else {
				/* Ownership errors are more important. */
				if (last_error.GetErrorMessage() != STR_ERROR_OWNED_BY) last_error = ret;
			}
		}

		if (tile == end_tile) break;

		tile += (axis == AXIS_Y) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
	}

	return had_success ? cost : last_error;
}

/**
 * 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
 * @param text unused
 * @return the cost of this operation or an error
 *
 * @todo When checking for the tile slope,
 * distingush between "Flat land required" and "land sloped in wrong direction"
 */
CommandCost CmdBuildRoadDepot(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
{
	DiagDirection dir = Extract<DiagDirection, 0, 2>(p1);
	RoadType rt = Extract<RoadType, 2, 2>(p1);

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

	Slope tileh = GetTileSlope(tile);
	if (tileh != SLOPE_FLAT && (
				!_settings_game.construction.build_on_slopes ||
				!CanBuildDepotByTileh(dir, tileh)
			)) {
		return_cmd_error(STR_ERROR_FLAT_LAND_REQUIRED);
	}

	CommandCost cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
	if (cost.Failed()) return cost;

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

	if (!Depot::CanAllocateItem()) return CMD_ERROR;

	if (flags & DC_EXEC) {
		Depot *dep = new Depot(tile);
		dep->build_date = _date;

		MakeRoadDepot(tile, _current_company, dep->index, dir, rt);
		MarkTileDirtyByTile(tile);
		MakeDefaultName(dep);
	}
	cost.AddCost(_price[PR_BUILD_DEPOT_ROAD]);
	return cost;
}

static CommandCost RemoveRoadDepot(TileIndex tile, DoCommandFlag flags)
{
	if (_current_company != OWNER_WATER) {
		CommandCost ret = CheckTileOwnership(tile);
		if (ret.Failed()) return ret;
	}

	CommandCost ret = EnsureNoVehicleOnGround(tile);
	if (ret.Failed()) return ret;

	if (flags & DC_EXEC) {
		delete Depot::GetByTile(tile);
		DoClearSquare(tile);
	}

	return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_CLEAR_DEPOT_ROAD]);
}

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

			/* Clear the road if only one piece is on the tile OR we are not using the DC_AUTO flag */
			if ((HasExactlyOneBit(b) && GetRoadBits(tile, ROADTYPE_TRAM) == ROAD_NONE) || !(flags & DC_AUTO)) {
				CommandCost ret(EXPENSES_CONSTRUCTION);
				RoadType rt;
				FOR_EACH_SET_ROADTYPE(rt, GetRoadTypes(tile)) {
					CommandCost tmp_ret = RemoveRoad(tile, flags, GetRoadBits(tile, rt), rt, true);
					if (tmp_ret.Failed()) return tmp_ret;
					ret.AddCost(tmp_ret);
				}
				return ret;
			}
			return_cmd_error(STR_ERROR_MUST_REMOVE_ROAD_FIRST);
		}

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

			if (flags & DC_AUTO) return_cmd_error(STR_ERROR_MUST_REMOVE_ROAD_FIRST);

			/* Must iterate over the roadtypes in a reverse manner because
			 * tram tracks must be removed before the road bits. */
			RoadType rt = ROADTYPE_TRAM;
			do {
				if (HasBit(rts, rt)) {
					CommandCost tmp_ret = RemoveRoad(tile, flags, GetCrossingRoadBits(tile), rt, false);
					if (tmp_ret.Failed()) return tmp_ret;
					ret.AddCost(tmp_ret);
				}
			} while (rt-- != ROADTYPE_ROAD);

			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_ERROR_BUILDING_MUST_BE_DEMOLISHED);
			}
			return RemoveRoadDepot(tile, flags);
	}
}


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

#include "table/road_land.h"

/**
 * Get the foundationtype of a RoadBits Slope combination
 *
 * @param tileh The Slope part
 * @param bits The RoadBits part
 * @return The resulting Foundation
 */
static Foundation GetRoadFoundation(Slope tileh, RoadBits bits)
{
	/* Flat land and land without a road doesn't require a foundation */
	if (tileh == SLOPE_FLAT || bits == ROAD_NONE) return FOUNDATION_NONE;

	/* Steep slopes behave the same as slopes with one corner raised. */
	if (IsSteepSlope(tileh)) {
		tileh = SlopeWithOneCornerRaised(GetHighestSlopeCorner(tileh));
	}

	/* Leveled RoadBits on a slope */
	if ((_invalid_tileh_slopes_road[0][tileh] & bits) == ROAD_NONE) return FOUNDATION_LEVELED;

	/* Straight roads without foundation on a slope */
	if (!IsSlopeWithOneCornerRaised(tileh) &&
			(_invalid_tileh_slopes_road[1][tileh] & bits) == ROAD_NONE)
		return FOUNDATION_NONE;

	/* Roads on steep Slopes or on Slopes with one corner raised */
	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) &&
			!(_settings_game.game_creation.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(const TileInfo *ti, RoadBits tram)
{
	/* Do not draw catenary if it is invisible */
	if (IsInvisibilitySet(TO_CATENARY)) return;

	/* Don't draw the catenary under a low bridge */
	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_CATENARY)) {
		int height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));

		if (height <= GetTileMaxZ(ti->tile) + 1) 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_CATENARY));
	AddSortableSpriteToDraw(front, PAL_NONE, ti->x, ti->y, 16, 16, TILE_HEIGHT + BB_HEIGHT_UNDER_BRIDGE, ti->z, IsTransparencySet(TO_CATENARY));
}

/**
 * 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, const TileInfo *ti, int dx, int dy, int h)
{
	int x = ti->x | dx;
	int y = ti->y | dy;
	int z = ti->z;
	if (ti->tileh != SLOPE_FLAT) z = GetSlopePixelZ(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);

	SpriteID image = 0;
	PaletteID pal = PAL_NONE;

	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] + SPR_ROAD_SLOPE_START;
	}

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

	Roadside 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) {
			DrawGroundSpriteAt(SPR_ONEWAY_BASE + drd - 1 + ((road == ROAD_X) ? 0 : 3), PAL_NONE, 8, 8, GetPartialPixelZ(8, 8, ti->tileh));
		}
	}

	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;

	/* Do not draw details (street lights, trees) under low bridge */
	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && (roadside == ROADSIDE_TREES || roadside == ROADSIDE_STREET_LIGHTS)) {
		int height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
		int minz = GetTileMaxZ(ti->tile) + 2;

		if (roadside == ROADSIDE_TREES) minz++;

		if (height < minz) return;
	}

	/* If there are no road bits, return, as there is nothing left to do */
	if (HasAtMostOneBit(road)) return;

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

/** Tile callback function for rendering a road tile to the screen */
static void DrawTile_Road(TileInfo *ti)
{
	switch (GetRoadTileType(ti->tile)) {
		case ROAD_TILE_NORMAL:
			DrawRoadBits(ti);
			break;

		case ROAD_TILE_CROSSING: {
			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			PaletteID pal = PAL_NONE;
			const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(ti->tile));

			if (rti->UsesOverlay()) {
				Axis axis = GetCrossingRailAxis(ti->tile);
				SpriteID road = SPR_ROAD_Y + axis;

				Roadside roadside = GetRoadside(ti->tile);

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

				DrawGroundSprite(road, pal);

				SpriteID rail = GetCustomRailSprite(rti, ti->tile, RTSG_CROSSING) + axis;
				/* Draw tracks, but draw PBS reserved tracks darker. */
				pal = (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasCrossingReservation(ti->tile)) ? PALETTE_CRASH : PAL_NONE;
				DrawGroundSprite(rail, pal);

				DrawRailTileSeq(ti, &_crossing_layout, TO_CATENARY, rail, 0, PAL_NONE);
			} else {
				SpriteID image = rti->base_sprites.crossing;

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

				Roadside roadside = GetRoadside(ti->tile);

				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);

				/* PBS debugging, draw reserved tracks darker */
				if (_game_mode != GM_MENU && _settings_client.gui.show_track_reservation && HasCrossingReservation(ti->tile)) {
					DrawGroundSprite(GetCrossingRoadAxis(ti->tile) == AXIS_Y ? GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_x : GetRailTypeInfo(GetRailType(ti->tile))->base_sprites.single_y, PALETTE_CRASH);
				}
			}

			if (HasTileRoadType(ti->tile, ROADTYPE_TRAM)) {
				DrawGroundSprite(SPR_TRAMWAY_OVERLAY + (GetCrossingRoadAxis(ti->tile) ^ 1), pal);
				DrawTramCatenary(ti, GetCrossingRoadBits(ti->tile));
			}
			if (HasCatenaryDrawn(GetRailType(ti->tile))) DrawCatenary(ti);
			break;
		}

		default:
		case ROAD_TILE_DEPOT: {
			if (ti->tileh != SLOPE_FLAT) DrawFoundation(ti, FOUNDATION_LEVELED);

			PaletteID palette = COMPANY_SPRITE_COLOUR(GetTileOwner(ti->tile));

			const DrawTileSprites *dts;
			if (HasTileRoadType(ti->tile, ROADTYPE_TRAM)) {
				dts =  &_tram_depot[GetRoadDepotDirection(ti->tile)];
			} else {
				dts =  &_road_depot[GetRoadDepotDirection(ti->tile)];
			}

			DrawGroundSprite(dts->ground.sprite, PAL_NONE);
			DrawOrigTileSeq(ti, dts, TO_BUILDINGS, palette);
			break;
		}
	}
	DrawBridgeMiddle(ti);
}

/**
 * Draw the road depot sprite.
 * @param x   The x offset to draw at.
 * @param y   The y offset to draw at.
 * @param dir The direction the depot must be facing.
 * @param rt  The road type of the depot to draw.
 */
void DrawRoadDepotSprite(int x, int y, DiagDirection dir, RoadType rt)
{
	PaletteID palette = COMPANY_SPRITE_COLOUR(_local_company);
	const DrawTileSprites *dts = (rt == ROADTYPE_TRAM) ? &_tram_depot[dir] : &_road_depot[dir];

	x += 33;
	y += 17;

	DrawSprite(dts->ground.sprite, PAL_NONE, x, y);
	DrawOrigTileSeqInGUI(x, y, dts, palette);
}

/**
 * Updates cached nearest town for all road tiles
 * @param invalidate are we just invalidating cached data?
 * @pre invalidate == true implies _generating_world == true
 */
void UpdateNearestTownForRoadTiles(bool invalidate)
{
	assert(!invalidate || _generating_world);

	for (TileIndex t = 0; t < MapSize(); t++) {
		if (IsTileType(t, MP_ROAD) && !IsRoadDepot(t) && !HasTownOwnedRoad(t)) {
			TownID tid = (TownID)INVALID_TOWN;
			if (!invalidate) {
				const Town *town = CalcClosestTownFromTile(t);
				if (town != NULL) tid = town->index;
			}
			SetTownIndex(t, tid);
		}
	}
}

static int GetSlopePixelZ_Road(TileIndex tile, uint x, uint y)
{

	if (IsNormalRoad(tile)) {
		int z;
		Slope tileh = GetTilePixelSlope(tile, &z);
		if (tileh == SLOPE_FLAT) return z;

		Foundation f = GetRoadFoundation(tileh, GetAllRoadBits(tile));
		z += ApplyPixelFoundationToSlope(f, &tileh);
		return z + GetPartialPixelZ(x & 0xF, y & 0xF, tileh);
	} else {
		return GetTileMaxPixelZ(tile);
	}
}

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

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 (_settings_game.game_creation.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 (IsRoadDepot(tile)) return;

	const Town *t = ClosestTownFromTile(tile, UINT_MAX);
	if (!HasRoadWorks(tile)) {
		HouseZonesBits grp = HZB_TOWN_EDGE;

		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 != HZB_TOWN_EDGE) &&
					IsNormalRoad(tile) && !HasAtMostOneBit(GetAllRoadBits(tile))) {
				if (GetFoundationSlope(tile) == SLOPE_FLAT && EnsureNoVehicleOnGround(tile).Succeeded() && 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 = (_settings_game.game_creation.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 (_settings_game.economy.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) {
				RemoveRoad(tile, DC_EXEC | DC_AUTO | DC_NO_WATER, (old_rb ^ new_rb), ROADTYPE_ROAD, true);
			}
		}

		MarkTileDirtyByTile(tile);
	}
}

static bool ClickTile_Road(TileIndex tile)
{
	if (!IsRoadDepot(tile)) return false;

	ShowDepotWindow(tile, VEH_ROAD);
	return true;
}

/* Converts RoadBits to TrackBits */
static const TrackBits _road_trackbits[16] = {
	TRACK_BIT_NONE,                                  // ROAD_NONE
	TRACK_BIT_NONE,                                  // ROAD_NW
	TRACK_BIT_NONE,                                  // ROAD_SW
	TRACK_BIT_LEFT,                                  // ROAD_W
	TRACK_BIT_NONE,                                  // ROAD_SE
	TRACK_BIT_Y,                                     // ROAD_Y
	TRACK_BIT_LOWER,                                 // ROAD_S
	TRACK_BIT_LEFT | TRACK_BIT_LOWER | TRACK_BIT_Y,  // ROAD_Y | ROAD_SW
	TRACK_BIT_NONE,                                  // ROAD_NE
	TRACK_BIT_UPPER,                                 // ROAD_N
	TRACK_BIT_X,                                     // ROAD_X
	TRACK_BIT_LEFT | TRACK_BIT_UPPER | TRACK_BIT_X,  // ROAD_X | ROAD_NW
	TRACK_BIT_RIGHT,                                 // ROAD_E
	TRACK_BIT_RIGHT | TRACK_BIT_UPPER | TRACK_BIT_Y, // ROAD_Y | ROAD_NE
	TRACK_BIT_RIGHT | TRACK_BIT_LOWER | TRACK_BIT_X, // ROAD_X | ROAD_SE
	TRACK_BIT_ALL,                                   // ROAD_ALL
};

static TrackStatus GetTileTrackStatus_Road(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
{
	TrackdirBits trackdirbits = TRACKDIR_BIT_NONE;
	TrackdirBits red_signals = TRACKDIR_BIT_NONE; // crossing barred
	switch (mode) {
		case TRANSPORT_RAIL:
			if (IsLevelCrossing(tile)) trackdirbits = TrackBitsToTrackdirBits(GetCrossingRailBits(tile));
			break;

		case TRANSPORT_ROAD:
			if ((GetRoadTypes(tile) & sub_mode) == 0) break;
			switch (GetRoadTileType(tile)) {
				case ROAD_TILE_NORMAL: {
					const uint drd_to_multiplier[DRD_END] = { 0x101, 0x100, 0x1, 0x0 };
					RoadType rt = (RoadType)FindFirstBit(sub_mode);
					RoadBits bits = GetRoadBits(tile, rt);

					/* no roadbit at this side of tile, return 0 */
					if (side != INVALID_DIAGDIR && (DiagDirToRoadBits(side) & bits) == 0) break;

					uint multiplier = drd_to_multiplier[rt == ROADTYPE_TRAM ? DRD_NONE : GetDisallowedRoadDirections(tile)];
					if (!HasRoadWorks(tile)) trackdirbits = (TrackdirBits)(_road_trackbits[bits] * multiplier);
					break;
				}

				case ROAD_TILE_CROSSING: {
					Axis axis = GetCrossingRoadAxis(tile);

					if (side != INVALID_DIAGDIR && axis != DiagDirToAxis(side)) break;

					trackdirbits = TrackBitsToTrackdirBits(AxisToTrackBits(axis));
					if (IsCrossingBarred(tile)) red_signals = trackdirbits;
					break;
				}

				default:
				case ROAD_TILE_DEPOT: {
					DiagDirection dir = GetRoadDepotDirection(tile);

					if (side != INVALID_DIAGDIR && side != dir) break;

					trackdirbits = TrackBitsToTrackdirBits(DiagDirToDiagTrackBits(dir));
					break;
				}
			}
			break;

		default: break;
	}
	return CombineTrackStatus(trackdirbits, red_signals);
}

static const StringID _road_tile_strings[] = {
	STR_LAI_ROAD_DESCRIPTION_ROAD,
	STR_LAI_ROAD_DESCRIPTION_ROAD,
	STR_LAI_ROAD_DESCRIPTION_ROAD,
	STR_LAI_ROAD_DESCRIPTION_ROAD_WITH_STREETLIGHTS,
	STR_LAI_ROAD_DESCRIPTION_ROAD,
	STR_LAI_ROAD_DESCRIPTION_TREE_LINED_ROAD,
	STR_LAI_ROAD_DESCRIPTION_ROAD,
	STR_LAI_ROAD_DESCRIPTION_ROAD,
};

static void GetTileDesc_Road(TileIndex tile, TileDesc *td)
{
	Owner rail_owner = INVALID_OWNER;
	Owner road_owner = INVALID_OWNER;
	Owner tram_owner = INVALID_OWNER;

	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_CROSSING: {
			td->str = STR_LAI_ROAD_DESCRIPTION_ROAD_RAIL_LEVEL_CROSSING;
			RoadTypes rts = GetRoadTypes(tile);
			rail_owner = GetTileOwner(tile);
			if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
			if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);

			const RailtypeInfo *rti = GetRailTypeInfo(GetRailType(tile));
			td->rail_speed = rti->max_speed;

			break;
		}

		case ROAD_TILE_DEPOT:
			td->str = STR_LAI_ROAD_DESCRIPTION_ROAD_VEHICLE_DEPOT;
			road_owner = GetTileOwner(tile); // Tile has only one owner, roadtype does not matter
			td->build_date = Depot::GetByTile(tile)->build_date;
			break;

		default: {
			RoadTypes rts = GetRoadTypes(tile);
			td->str = (HasBit(rts, ROADTYPE_ROAD) ? _road_tile_strings[GetRoadside(tile)] : STR_LAI_ROAD_DESCRIPTION_TRAMWAY);
			if (HasBit(rts, ROADTYPE_ROAD)) road_owner = GetRoadOwner(tile, ROADTYPE_ROAD);
			if (HasBit(rts, ROADTYPE_TRAM)) tram_owner = GetRoadOwner(tile, ROADTYPE_TRAM);
			break;
		}
	}

	/* Now we have to discover, if the tile has only one owner or many:
	 *   - Find a first_owner of the tile. (Currently road or tram must be present, but this will break when the third type becomes available)
	 *   - Compare the found owner with the other owners, and test if they differ.
	 * Note: If road exists it will be the first_owner.
	 */
	Owner first_owner = (road_owner == INVALID_OWNER ? tram_owner : road_owner);
	bool mixed_owners = (tram_owner != INVALID_OWNER && tram_owner != first_owner) || (rail_owner != INVALID_OWNER && rail_owner != first_owner);

	if (mixed_owners) {
		/* Multiple owners */
		td->owner_type[0] = (rail_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_RAIL_OWNER);
		td->owner[0] = rail_owner;
		td->owner_type[1] = (road_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_ROAD_OWNER);
		td->owner[1] = road_owner;
		td->owner_type[2] = (tram_owner == INVALID_OWNER ? STR_NULL : STR_LAND_AREA_INFORMATION_TRAM_OWNER);
		td->owner[2] = tram_owner;
	} else {
		/* One to rule them all */
		td->owner[0] = first_owner;
	}
}

/**
 * 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 VehicleEnterTileStatus VehicleEnter_Road(Vehicle *v, TileIndex tile, int x, int y)
{
	switch (GetRoadTileType(tile)) {
		case ROAD_TILE_DEPOT: {
			if (v->type != VEH_ROAD) break;

			RoadVehicle *rv = RoadVehicle::From(v);
			if (rv->frame == RVC_DEPOT_STOP_FRAME &&
					_roadveh_enter_depot_dir[GetRoadDepotDirection(tile)] == rv->state) {
				rv->state = RVSB_IN_DEPOT;
				rv->vehstatus |= VS_HIDDEN;
				rv->direction = ReverseDir(rv->direction);
				if (rv->Next() == NULL) VehicleEnterDepot(rv->First());
				rv->tile = tile;

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

		default: break;
	}
	return VETSB_CONTINUE;
}


static void ChangeTileOwner_Road(TileIndex tile, Owner old_owner, Owner new_owner)
{
	if (IsRoadDepot(tile)) {
		if (GetTileOwner(tile) == old_owner) {
			if (new_owner == INVALID_OWNER) {
				DoCommand(tile, 0, 0, DC_EXEC | DC_BANKRUPT, CMD_LANDSCAPE_CLEAR);
			} else {
				SetTileOwner(tile, new_owner);
			}
		}
		return;
	}

	for (RoadType rt = ROADTYPE_ROAD; rt < ROADTYPE_END; rt++) {
		/* Update all roadtypes, no matter if they are present */
		if (GetRoadOwner(tile, rt) == old_owner) {
			SetRoadOwner(tile, rt, new_owner == INVALID_OWNER ? OWNER_NONE : new_owner);
		}
	}

	if (IsLevelCrossing(tile)) {
		if (GetTileOwner(tile) == old_owner) {
			if (new_owner == INVALID_OWNER) {
				DoCommand(tile, 0, GetCrossingRailTrack(tile), DC_EXEC | DC_BANKRUPT, CMD_REMOVE_SINGLE_RAIL);
			} else {
				SetTileOwner(tile, new_owner);
			}
		}
	}
}

static CommandCost TerraformTile_Road(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
{
	if (_settings_game.construction.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 CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
				break;

			case ROAD_TILE_DEPOT:
				if (AutoslopeCheckForEntranceEdge(tile, z_new, tileh_new, GetRoadDepotDirection(tile))) return CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
				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 safe to call GetRoadFoundation(). */
				if (CheckRoadSlope(tileh_new, &bits_copy, ROAD_NONE, ROAD_NONE).Succeeded()) {
					/* CheckRoadSlope() sometimes changes the road_bits, if it does not agree with them. */
					if (bits == bits_copy) {
						int 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 CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_FOUNDATION]);
					}
				}
				break;
			}

			default: NOT_REACHED();
		}
	}

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

/** Tile callback functions for road tiles */
extern const TileTypeProcs _tile_type_road_procs = {
	DrawTile_Road,           // draw_tile_proc
	GetSlopePixelZ_Road,     // get_slope_z_proc
	ClearTile_Road,          // clear_tile_proc
	NULL,                    // add_accepted_cargo_proc
	GetTileDesc_Road,        // get_tile_desc_proc
	GetTileTrackStatus_Road, // get_tile_track_status_proc
	ClickTile_Road,          // click_tile_proc
	NULL,                    // animate_tile_proc
	TileLoop_Road,           // tile_loop_proc
	ChangeTileOwner_Road,    // change_tile_owner_proc
	NULL,                    // add_produced_cargo_proc
	VehicleEnter_Road,       // vehicle_enter_tile_proc
	GetFoundation_Road,      // get_foundation_proc
	TerraformTile_Road,      // terraform_tile_proc
};