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follow_track.hpp
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1 /* $Id: follow_track.hpp 27418 2015-10-30 16:18:03Z frosch $ */
2
3 /*
4 * This file is part of OpenTTD.
5 * 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.
6 * 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.
7 * 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/>.
8 */
9
12 #ifndef FOLLOW_TRACK_HPP
13 #define FOLLOW_TRACK_HPP
14
15 #include "../pbs.h"
16 #include "../roadveh.h"
17 #include "../station_base.h"
18 #include "../train.h"
19 #include "../tunnelbridge.h"
20 #include "../tunnelbridge_map.h"
21 #include "../depot_map.h"
22 #include "pf_performance_timer.hpp"
23
29 template <TransportType Ttr_type_, typename VehicleType, bool T90deg_turns_allowed_ = true, bool Tmask_reserved_tracks = false>
30 struct CFollowTrackT
31 {
32 enum ErrorCode {
33 EC_NONE,
34 EC_OWNER,
35 EC_RAIL_TYPE,
36 EC_90DEG,
37 EC_NO_WAY,
38 EC_RESERVED,
39 };
40
41 const VehicleType *m_veh;
42 Owner m_veh_owner;
43 TileIndex m_old_tile;
44 Trackdir m_old_td;
45 TileIndex m_new_tile;
46 TrackdirBits m_new_td_bits;
47 DiagDirection m_exitdir;
48 bool m_is_tunnel;
49 bool m_is_bridge;
50 bool m_is_station;
51 int m_tiles_skipped;
52 ErrorCode m_err;
53 CPerformanceTimer *m_pPerf;
54 RailTypes m_railtypes;
55
56 inline CFollowTrackT(const VehicleType *v = NULL, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
57 {
58 Init(v, railtype_override, pPerf);
59 }
60
61 inline CFollowTrackT(Owner o, RailTypes railtype_override = INVALID_RAILTYPES, CPerformanceTimer *pPerf = NULL)
62 {
63 m_veh = NULL;
64 Init(o, railtype_override, pPerf);
65 }
66
67 inline void Init(const VehicleType *v, RailTypes railtype_override, CPerformanceTimer *pPerf)
68 {
69 assert(!IsRailTT() || (v != NULL && v->type == VEH_TRAIN));
70 m_veh = v;
71 Init(v != NULL ? v->owner : INVALID_OWNER, IsRailTT() && railtype_override == INVALID_RAILTYPES ? Train::From(v)->compatible_railtypes : railtype_override, pPerf);
72 }
73
74 inline void Init(Owner o, RailTypes railtype_override, CPerformanceTimer *pPerf)
75 {
76 assert((!IsRoadTT() || m_veh != NULL) && (!IsRailTT() || railtype_override != INVALID_RAILTYPES));
77 m_veh_owner = o;
78 m_pPerf = pPerf;
79 /* don't worry, all is inlined so compiler should remove unnecessary initializations */
80 m_old_tile = INVALID_TILE;
81 m_old_td = INVALID_TRACKDIR;
82 m_new_tile = INVALID_TILE;
83 m_new_td_bits = TRACKDIR_BIT_NONE;
84 m_exitdir = INVALID_DIAGDIR;
85 m_is_station = m_is_bridge = m_is_tunnel = false;
86 m_tiles_skipped = 0;
87 m_err = EC_NONE;
88 m_railtypes = railtype_override;
89 }
90
91 inline static TransportType TT() { return Ttr_type_; }
92 inline static bool IsWaterTT() { return TT() == TRANSPORT_WATER; }
93 inline static bool IsRailTT() { return TT() == TRANSPORT_RAIL; }
94 inline bool IsTram() { return IsRoadTT() && HasBit(RoadVehicle::From(m_veh)->compatible_roadtypes, ROADTYPE_TRAM); }
95 inline static bool IsRoadTT() { return TT() == TRANSPORT_ROAD; }
96 inline static bool Allow90degTurns() { return T90deg_turns_allowed_; }
97 inline static bool DoTrackMasking() { return Tmask_reserved_tracks; }
98
100 inline DiagDirection GetSingleTramBit(TileIndex tile)
101 {
102 assert(IsTram()); // this function shouldn't be called in other cases
103
104 if (IsNormalRoadTile(tile)) {
105 RoadBits rb = GetRoadBits(tile, ROADTYPE_TRAM);
106 switch (rb) {
107 case ROAD_NW: return DIAGDIR_NW;
108 case ROAD_SW: return DIAGDIR_SW;
109 case ROAD_SE: return DIAGDIR_SE;
110 case ROAD_NE: return DIAGDIR_NE;
111 default: break;
112 }
113 }
114 return INVALID_DIAGDIR;
115 }
116
121 inline bool Follow(TileIndex old_tile, Trackdir old_td)
122 {
123 m_old_tile = old_tile;
124 m_old_td = old_td;
125 m_err = EC_NONE;
126 assert(((TrackStatusToTrackdirBits(GetTileTrackStatus(m_old_tile, TT(), IsRoadTT() ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0)) & TrackdirToTrackdirBits(m_old_td)) != 0) ||
127 (IsTram() && GetSingleTramBit(m_old_tile) != INVALID_DIAGDIR)); // Disable the assertion for single tram bits
128 m_exitdir = TrackdirToExitdir(m_old_td);
129 if (ForcedReverse()) return true;
130 if (!CanExitOldTile()) return false;
131 FollowTileExit();
132 if (!QueryNewTileTrackStatus()) return TryReverse();
133 m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
134 if (m_new_td_bits == TRACKDIR_BIT_NONE || !CanEnterNewTile()) {
135 /* In case we can't enter the next tile, but are
136 * a normal road vehicle, then we can actually
137 * try to reverse as this is the end of the road.
138 * Trams can only turn on the appropriate bits in
139 * which case reaching this would mean a dead end
140 * near a building and in that case there would
141 * a "false" QueryNewTileTrackStatus result and
142 * as such reversing is already tried. The fact
143 * that function failed can have to do with a
144 * missing road bit, or inability to connect the
145 * different bits due to slopes. */
146 if (IsRoadTT() && !IsTram() && TryReverse()) return true;
147
148 /* CanEnterNewTile already set a reason.
149 * Do NOT overwrite it (important for example for EC_RAIL_TYPE).
150 * Only set a reason if CanEnterNewTile was not called */
151 if (m_new_td_bits == TRACKDIR_BIT_NONE) m_err = EC_NO_WAY;
152
153 return false;
154 }
155 if (!Allow90degTurns()) {
156 m_new_td_bits &= (TrackdirBits)~(int)TrackdirCrossesTrackdirs(m_old_td);
157 if (m_new_td_bits == TRACKDIR_BIT_NONE) {
158 m_err = EC_90DEG;
159 return false;
160 }
161 }
162 return true;
163 }
164
165 inline bool MaskReservedTracks()
166 {
167 if (!DoTrackMasking()) return true;
168
169 if (m_is_station) {
170 /* Check skipped station tiles as well. */
171 TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
172 for (TileIndex tile = m_new_tile - diff * m_tiles_skipped; tile != m_new_tile; tile += diff) {
173 if (HasStationReservation(tile)) {
174 m_new_td_bits = TRACKDIR_BIT_NONE;
175 m_err = EC_RESERVED;
176 return false;
177 }
178 }
179 }
180
181 TrackBits reserved = GetReservedTrackbits(m_new_tile);
182 /* Mask already reserved trackdirs. */
183 m_new_td_bits &= ~TrackBitsToTrackdirBits(reserved);
184 /* Mask out all trackdirs that conflict with the reservation. */
185 Track t;
186 FOR_EACH_SET_TRACK(t, TrackdirBitsToTrackBits(m_new_td_bits)) {
187 if (TracksOverlap(reserved | TrackToTrackBits(t))) m_new_td_bits &= ~TrackToTrackdirBits(t);
188 }
189 if (m_new_td_bits == TRACKDIR_BIT_NONE) {
190 m_err = EC_RESERVED;
191 return false;
192 }
193 return true;
194 }
195
196 protected:
198 inline void FollowTileExit()
199 {
200 m_is_station = m_is_bridge = m_is_tunnel = false;
201 m_tiles_skipped = 0;
202
203 /* extra handling for tunnels and bridges in our direction */
204 if (IsTileType(m_old_tile, MP_TUNNELBRIDGE)) {
205 DiagDirection enterdir = GetTunnelBridgeDirection(m_old_tile);
206 if (enterdir == m_exitdir) {
207 /* we are entering the tunnel / bridge */
208 if (IsTunnel(m_old_tile)) {
209 m_is_tunnel = true;
210 m_new_tile = GetOtherTunnelEnd(m_old_tile);
211 } else { // IsBridge(m_old_tile)
212 m_is_bridge = true;
213 m_new_tile = GetOtherBridgeEnd(m_old_tile);
214 }
215 m_tiles_skipped = GetTunnelBridgeLength(m_new_tile, m_old_tile);
216 return;
217 }
218 assert(ReverseDiagDir(enterdir) == m_exitdir);
219 }
220
221 /* normal or station tile, do one step */
222 TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
223 m_new_tile = TILE_ADD(m_old_tile, diff);
224
225 /* special handling for stations */
226 if (IsRailTT() && HasStationTileRail(m_new_tile)) {
227 m_is_station = true;
228 } else if (IsRoadTT() && IsRoadStopTile(m_new_tile)) {
229 m_is_station = true;
230 } else {
231 m_is_station = false;
232 }
233 }
234
236 inline bool QueryNewTileTrackStatus()
237 {
238 CPerfStart perf(*m_pPerf);
239 if (IsRailTT() && IsPlainRailTile(m_new_tile)) {
240 m_new_td_bits = (TrackdirBits)(GetTrackBits(m_new_tile) * 0x101);
241 } else {
242 m_new_td_bits = TrackStatusToTrackdirBits(GetTileTrackStatus(m_new_tile, TT(), IsRoadTT() ? RoadVehicle::From(m_veh)->compatible_roadtypes : 0));
243
244 if (IsTram() && m_new_td_bits == 0) {
245 /* GetTileTrackStatus() returns 0 for single tram bits.
246 * As we cannot change it there (easily) without breaking something, change it here */
247 switch (GetSingleTramBit(m_new_tile)) {
248 case DIAGDIR_NE:
249 case DIAGDIR_SW:
250 m_new_td_bits = TRACKDIR_BIT_X_NE | TRACKDIR_BIT_X_SW;
251 break;
252
253 case DIAGDIR_NW:
254 case DIAGDIR_SE:
255 m_new_td_bits = TRACKDIR_BIT_Y_NW | TRACKDIR_BIT_Y_SE;
256 break;
257
258 default: break;
259 }
260 }
261 }
262 return (m_new_td_bits != TRACKDIR_BIT_NONE);
263 }
264
266 inline bool CanExitOldTile()
267 {
268 /* road stop can be left at one direction only unless it's a drive-through stop */
269 if (IsRoadTT() && IsStandardRoadStopTile(m_old_tile)) {
270 DiagDirection exitdir = GetRoadStopDir(m_old_tile);
271 if (exitdir != m_exitdir) {
272 m_err = EC_NO_WAY;
273 return false;
274 }
275 }
276
277 /* single tram bits can only be left in one direction */
278 if (IsTram()) {
279 DiagDirection single_tram = GetSingleTramBit(m_old_tile);
280 if (single_tram != INVALID_DIAGDIR && single_tram != m_exitdir) {
281 m_err = EC_NO_WAY;
282 return false;
283 }
284 }
285
286 /* road depots can be also left in one direction only */
287 if (IsRoadTT() && IsDepotTypeTile(m_old_tile, TT())) {
288 DiagDirection exitdir = GetRoadDepotDirection(m_old_tile);
289 if (exitdir != m_exitdir) {
290 m_err = EC_NO_WAY;
291 return false;
292 }
293 }
294 return true;
295 }
296
298 inline bool CanEnterNewTile()
299 {
300 if (IsRoadTT() && IsStandardRoadStopTile(m_new_tile)) {
301 /* road stop can be entered from one direction only unless it's a drive-through stop */
302 DiagDirection exitdir = GetRoadStopDir(m_new_tile);
303 if (ReverseDiagDir(exitdir) != m_exitdir) {
304 m_err = EC_NO_WAY;
305 return false;
306 }
307 }
308
309 /* single tram bits can only be entered from one direction */
310 if (IsTram()) {
311 DiagDirection single_tram = GetSingleTramBit(m_new_tile);
312 if (single_tram != INVALID_DIAGDIR && single_tram != ReverseDiagDir(m_exitdir)) {
313 m_err = EC_NO_WAY;
314 return false;
315 }
316 }
317
318 /* road and rail depots can also be entered from one direction only */
319 if (IsRoadTT() && IsDepotTypeTile(m_new_tile, TT())) {
320 DiagDirection exitdir = GetRoadDepotDirection(m_new_tile);
321 if (ReverseDiagDir(exitdir) != m_exitdir) {
322 m_err = EC_NO_WAY;
323 return false;
324 }
325 /* don't try to enter other company's depots */
326 if (GetTileOwner(m_new_tile) != m_veh_owner) {
327 m_err = EC_OWNER;
328 return false;
329 }
330 }
331 if (IsRailTT() && IsDepotTypeTile(m_new_tile, TT())) {
332 DiagDirection exitdir = GetRailDepotDirection(m_new_tile);
333 if (ReverseDiagDir(exitdir) != m_exitdir) {
334 m_err = EC_NO_WAY;
335 return false;
336 }
337 }
338
339 /* rail transport is possible only on tiles with the same owner as vehicle */
340 if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh_owner) {
341 /* different owner */
342 m_err = EC_NO_WAY;
343 return false;
344 }
345
346 /* rail transport is possible only on compatible rail types */
347 if (IsRailTT()) {
348 RailType rail_type = GetTileRailType(m_new_tile);
349 if (!HasBit(m_railtypes, rail_type)) {
350 /* incompatible rail type */
351 m_err = EC_RAIL_TYPE;
352 return false;
353 }
354 }
355
356 /* tunnel holes and bridge ramps can be entered only from proper direction */
357 if (IsTileType(m_new_tile, MP_TUNNELBRIDGE)) {
358 if (IsTunnel(m_new_tile)) {
359 if (!m_is_tunnel) {
360 DiagDirection tunnel_enterdir = GetTunnelBridgeDirection(m_new_tile);
361 if (tunnel_enterdir != m_exitdir) {
362 m_err = EC_NO_WAY;
363 return false;
364 }
365 }
366 } else { // IsBridge(m_new_tile)
367 if (!m_is_bridge) {
368 DiagDirection ramp_enderdir = GetTunnelBridgeDirection(m_new_tile);
369 if (ramp_enderdir != m_exitdir) {
370 m_err = EC_NO_WAY;
371 return false;
372 }
373 }
374 }
375 }
376
377 /* special handling for rail stations - get to the end of platform */
378 if (IsRailTT() && m_is_station) {
379 /* entered railway station
380 * get platform length */
381 uint length = BaseStation::GetByTile(m_new_tile)->GetPlatformLength(m_new_tile, TrackdirToExitdir(m_old_td));
382 /* how big step we must do to get to the last platform tile; */
383 m_tiles_skipped = length - 1;
384 /* move to the platform end */
385 TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
386 diff *= m_tiles_skipped;
387 m_new_tile = TILE_ADD(m_new_tile, diff);
388 return true;
389 }
390
391 return true;
392 }
393
395 inline bool ForcedReverse()
396 {
397 /* rail and road depots cause reversing */
398 if (!IsWaterTT() && IsDepotTypeTile(m_old_tile, TT())) {
399 DiagDirection exitdir = IsRailTT() ? GetRailDepotDirection(m_old_tile) : GetRoadDepotDirection(m_old_tile);
400 if (exitdir != m_exitdir) {
401 /* reverse */
402 m_new_tile = m_old_tile;
403 m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
404 m_exitdir = exitdir;
405 m_tiles_skipped = 0;
406 m_is_tunnel = m_is_bridge = m_is_station = false;
407 return true;
408 }
409 }
410
411 /* single tram bits cause reversing */
412 if (IsTram() && GetSingleTramBit(m_old_tile) == ReverseDiagDir(m_exitdir)) {
413 /* reverse */
414 m_new_tile = m_old_tile;
415 m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
416 m_exitdir = ReverseDiagDir(m_exitdir);
417 m_tiles_skipped = 0;
418 m_is_tunnel = m_is_bridge = m_is_station = false;
419 return true;
420 }
421
422 return false;
423 }
424
426 inline bool TryReverse()
427 {
428 if (IsRoadTT() && !IsTram()) {
429 /* if we reached the end of road, we can reverse the RV and continue moving */
430 m_exitdir = ReverseDiagDir(m_exitdir);
431 /* new tile will be the same as old one */
432 m_new_tile = m_old_tile;
433 /* set new trackdir bits to all reachable trackdirs */
434 QueryNewTileTrackStatus();
435 m_new_td_bits &= DiagdirReachesTrackdirs(m_exitdir);
436 if (m_new_td_bits != TRACKDIR_BIT_NONE) {
437 /* we have some trackdirs reachable after reversal */
438 return true;
439 }
440 }
441 m_err = EC_NO_WAY;
442 return false;
443 }
444
445 public:
447 int GetSpeedLimit(int *pmin_speed = NULL) const
448 {
449 int min_speed = 0;
450 int max_speed = INT_MAX; // no limit
451
452 /* Check for on-bridge speed limit */
453 if (!IsWaterTT() && IsBridgeTile(m_old_tile)) {
454 int spd = GetBridgeSpec(GetBridgeType(m_old_tile))->speed;
455 if (IsRoadTT()) spd *= 2;
456 if (max_speed > spd) max_speed = spd;
457 }
458 /* Check for speed limit imposed by railtype */
459 if (IsRailTT()) {
460 uint16 rail_speed = GetRailTypeInfo(GetRailType(m_old_tile))->max_speed;
461 if (rail_speed > 0) max_speed = min(max_speed, rail_speed);
462 }
463
464 /* if min speed was requested, return it */
465 if (pmin_speed != NULL) *pmin_speed = min_speed;
466 return max_speed;
467 }
468 };
469
470 typedef CFollowTrackT<TRANSPORT_WATER, Ship, true > CFollowTrackWater;
471 typedef CFollowTrackT<TRANSPORT_ROAD, RoadVehicle, true > CFollowTrackRoad;
472 typedef CFollowTrackT<TRANSPORT_RAIL, Train, true > CFollowTrackRail;
473
474 typedef CFollowTrackT<TRANSPORT_WATER, Ship, false> CFollowTrackWaterNo90;
475 typedef CFollowTrackT<TRANSPORT_ROAD, RoadVehicle, false> CFollowTrackRoadNo90;
476 typedef CFollowTrackT<TRANSPORT_RAIL, Train, false> CFollowTrackRailNo90;
477
478 typedef CFollowTrackT<TRANSPORT_RAIL, Train, true, true > CFollowTrackFreeRail;
479 typedef CFollowTrackT<TRANSPORT_RAIL, Train, false, true > CFollowTrackFreeRailNo90;
480
481 #endif /* FOLLOW_TRACK_HPP */