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00012 #include "ai_rail.hpp"
00013 #include "ai_map.hpp"
00014 #include "ai_station.hpp"
00015 #include "../../command_type.h"
00016 #include "../../debug.h"
00017 #include "../../station_base.h"
00018 #include "../../company_func.h"
00019 #include "../../newgrf_generic.h"
00020 #include "../../newgrf_station.h"
00021
00022 bool AIRail::IsRailTile(TileIndex tile)
00023 {
00024 if (!::IsValidTile(tile)) return false;
00025
00026 return (::IsTileType(tile, MP_RAILWAY) && !::IsRailDepot(tile)) ||
00027 (::HasStationTileRail(tile) && !::IsStationTileBlocked(tile)) || ::IsLevelCrossingTile(tile);
00028 }
00029
00030 bool AIRail::IsLevelCrossingTile(TileIndex tile)
00031 {
00032 if (!::IsValidTile(tile)) return false;
00033
00034 return ::IsLevelCrossingTile(tile);
00035 }
00036
00037 bool AIRail::IsRailDepotTile(TileIndex tile)
00038 {
00039 if (!::IsValidTile(tile)) return false;
00040
00041 return ::IsRailDepotTile(tile);
00042 }
00043
00044 bool AIRail::IsRailStationTile(TileIndex tile)
00045 {
00046 if (!::IsValidTile(tile)) return false;
00047
00048 return ::IsRailStationTile(tile);
00049 }
00050
00051 bool AIRail::IsRailWaypointTile(TileIndex tile)
00052 {
00053 if (!::IsValidTile(tile)) return false;
00054
00055 return ::IsRailWaypointTile(tile);
00056 }
00057
00058 bool AIRail::IsRailTypeAvailable(RailType rail_type)
00059 {
00060 if ((::RailType)rail_type < RAILTYPE_BEGIN || (::RailType)rail_type >= RAILTYPE_END) return false;
00061
00062 return ::HasRailtypeAvail(_current_company, (::RailType)rail_type);
00063 }
00064
00065 AIRail::RailType AIRail::GetCurrentRailType()
00066 {
00067 return (RailType)AIObject::GetRailType();
00068 }
00069
00070 void AIRail::SetCurrentRailType(RailType rail_type)
00071 {
00072 if (!IsRailTypeAvailable(rail_type)) return;
00073
00074 AIObject::SetRailType((::RailType)rail_type);
00075 }
00076
00077 bool AIRail::TrainCanRunOnRail(AIRail::RailType engine_rail_type, AIRail::RailType track_rail_type)
00078 {
00079 if (!AIRail::IsRailTypeAvailable(engine_rail_type)) return false;
00080 if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;
00081
00082 return ::IsCompatibleRail((::RailType)engine_rail_type, (::RailType)track_rail_type);
00083 }
00084
00085 bool AIRail::TrainHasPowerOnRail(AIRail::RailType engine_rail_type, AIRail::RailType track_rail_type)
00086 {\
00087 if (!AIRail::IsRailTypeAvailable(engine_rail_type)) return false;
00088 if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;
00089
00090 return ::HasPowerOnRail((::RailType)engine_rail_type, (::RailType)track_rail_type);
00091 }
00092
00093 AIRail::RailType AIRail::GetRailType(TileIndex tile)
00094 {
00095 if (!AITile::HasTransportType(tile, AITile::TRANSPORT_RAIL)) return RAILTYPE_INVALID;
00096
00097 return (RailType)::GetRailType(tile);
00098 }
00099
00100 bool AIRail::ConvertRailType(TileIndex start_tile, TileIndex end_tile, AIRail::RailType convert_to)
00101 {
00102 EnforcePrecondition(false, ::IsValidTile(start_tile));
00103 EnforcePrecondition(false, ::IsValidTile(end_tile));
00104 EnforcePrecondition(false, IsRailTypeAvailable(convert_to));
00105
00106 return AIObject::DoCommand(start_tile, end_tile, convert_to, CMD_CONVERT_RAIL);
00107 }
00108
00109 TileIndex AIRail::GetRailDepotFrontTile(TileIndex depot)
00110 {
00111 if (!IsRailDepotTile(depot)) return INVALID_TILE;
00112
00113 return depot + ::TileOffsByDiagDir(::GetRailDepotDirection(depot));
00114 }
00115
00116 AIRail::RailTrack AIRail::GetRailStationDirection(TileIndex tile)
00117 {
00118 if (!IsRailStationTile(tile)) return RAILTRACK_INVALID;
00119
00120 return (RailTrack)::GetRailStationTrackBits(tile);
00121 }
00122
00123 bool AIRail::BuildRailDepot(TileIndex tile, TileIndex front)
00124 {
00125 EnforcePrecondition(false, tile != front);
00126 EnforcePrecondition(false, ::IsValidTile(tile));
00127 EnforcePrecondition(false, ::IsValidTile(front));
00128 EnforcePrecondition(false, ::TileX(tile) == ::TileX(front) || ::TileY(tile) == ::TileY(front));
00129 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00130
00131 uint entrance_dir = (::TileX(tile) == ::TileX(front)) ? (::TileY(tile) < ::TileY(front) ? 1 : 3) : (::TileX(tile) < ::TileX(front) ? 2 : 0);
00132
00133 return AIObject::DoCommand(tile, AIObject::GetRailType(), entrance_dir, CMD_BUILD_TRAIN_DEPOT);
00134 }
00135
00136 bool AIRail::BuildRailStation(TileIndex tile, RailTrack direction, uint num_platforms, uint platform_length, StationID station_id)
00137 {
00138 EnforcePrecondition(false, ::IsValidTile(tile));
00139 EnforcePrecondition(false, direction == RAILTRACK_NW_SE || direction == RAILTRACK_NE_SW);
00140 EnforcePrecondition(false, num_platforms > 0 && num_platforms <= 0xFF);
00141 EnforcePrecondition(false, platform_length > 0 && platform_length <= 0xFF);
00142 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00143 EnforcePrecondition(false, station_id == AIStation::STATION_NEW || station_id == AIStation::STATION_JOIN_ADJACENT || AIStation::IsValidStation(station_id));
00144
00145 uint32 p1 = GetCurrentRailType() | (platform_length << 16) | (num_platforms << 8);
00146 if (direction == RAILTRACK_NW_SE) p1 |= (1 << 4);
00147 if (station_id != AIStation::STATION_JOIN_ADJACENT) p1 |= (1 << 24);
00148 return AIObject::DoCommand(tile, p1, (AIStation::IsValidStation(station_id) ? station_id : INVALID_STATION) << 16, CMD_BUILD_RAIL_STATION);
00149 }
00150
00151 bool AIRail::BuildNewGRFRailStation(TileIndex tile, RailTrack direction, uint num_platforms, uint platform_length, StationID station_id, CargoID cargo_id, IndustryType source_industry, IndustryType goal_industry, int distance, bool source_station)
00152 {
00153 EnforcePrecondition(false, ::IsValidTile(tile));
00154 EnforcePrecondition(false, direction == RAILTRACK_NW_SE || direction == RAILTRACK_NE_SW);
00155 EnforcePrecondition(false, num_platforms > 0 && num_platforms <= 0xFF);
00156 EnforcePrecondition(false, platform_length > 0 && platform_length <= 0xFF);
00157 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00158 EnforcePrecondition(false, station_id == AIStation::STATION_NEW || station_id == AIStation::STATION_JOIN_ADJACENT || AIStation::IsValidStation(station_id));
00159
00160 uint32 p1 = GetCurrentRailType() | (platform_length << 16) | (num_platforms << 8);
00161 if (direction == RAILTRACK_NW_SE) p1 |= 1 << 4;
00162 if (station_id != AIStation::STATION_JOIN_ADJACENT) p1 |= (1 << 24);
00163
00164 const GRFFile *file;
00165 uint16 res = GetAiPurchaseCallbackResult(GSF_STATION, cargo_id, 0, source_industry, goal_industry, min(255, distance / 2), AICE_STATION_GET_STATION_ID, source_station ? 0 : 1, min(15, num_platforms) << 4 | min(15, platform_length), &file);
00166 uint32 p2 = (AIStation::IsValidStation(station_id) ? station_id : INVALID_STATION) << 16;
00167 if (res != CALLBACK_FAILED) {
00168 int index = 0;
00169 const StationSpec *spec = GetCustomStationSpecByGrf(file->grfid, res, &index);
00170 if (spec == NULL) {
00171 DEBUG(grf, 1, "%s returned an invalid station ID for 'AI construction/purchase selection (18)' callback", file->filename);
00172 } else {
00173 p2 |= spec->sclass | index << 8;
00174 }
00175
00176 }
00177 return AIObject::DoCommand(tile, p1, p2, CMD_BUILD_RAIL_STATION);
00178 }
00179
00180 bool AIRail::BuildRailWaypoint(TileIndex tile)
00181 {
00182 EnforcePrecondition(false, ::IsValidTile(tile));
00183 EnforcePrecondition(false, IsRailTile(tile));
00184 EnforcePrecondition(false, GetRailTracks(tile) == RAILTRACK_NE_SW || GetRailTracks(tile) == RAILTRACK_NW_SE);
00185 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00186
00187 return AIObject::DoCommand(tile, GetCurrentRailType() | (GetRailTracks(tile) == RAILTRACK_NE_SW ? AXIS_X : AXIS_Y) << 4 | 1 << 8 | 1 << 16, STAT_CLASS_WAYP | INVALID_STATION << 16, CMD_BUILD_RAIL_WAYPOINT);
00188 }
00189
00190 bool AIRail::RemoveRailWaypointTileRectangle(TileIndex tile, TileIndex tile2, bool keep_rail)
00191 {
00192 EnforcePrecondition(false, ::IsValidTile(tile));
00193 EnforcePrecondition(false, ::IsValidTile(tile2));
00194
00195 return AIObject::DoCommand(tile, tile2, keep_rail ? 1 : 0, CMD_REMOVE_FROM_RAIL_WAYPOINT);
00196 }
00197
00198 bool AIRail::RemoveRailStationTileRectangle(TileIndex tile, TileIndex tile2, bool keep_rail)
00199 {
00200 EnforcePrecondition(false, ::IsValidTile(tile));
00201 EnforcePrecondition(false, ::IsValidTile(tile2));
00202
00203 return AIObject::DoCommand(tile, tile2, keep_rail ? 1 : 0, CMD_REMOVE_FROM_RAIL_STATION);
00204 }
00205
00206 uint AIRail::GetRailTracks(TileIndex tile)
00207 {
00208 if (!IsRailTile(tile)) return RAILTRACK_INVALID;
00209
00210 if (IsRailStationTile(tile) || IsRailWaypointTile(tile)) return ::TrackToTrackBits(::GetRailStationTrack(tile));
00211 if (IsLevelCrossingTile(tile)) return ::GetCrossingRailBits(tile);
00212 if (IsRailDepotTile(tile)) return ::TRACK_BIT_NONE;
00213 return ::GetTrackBits(tile);
00214 }
00215
00216 bool AIRail::BuildRailTrack(TileIndex tile, RailTrack rail_track)
00217 {
00218 EnforcePrecondition(false, ::IsValidTile(tile));
00219 EnforcePrecondition(false, rail_track != 0);
00220 EnforcePrecondition(false, (rail_track & ~::TRACK_BIT_ALL) == 0);
00221 EnforcePrecondition(false, KillFirstBit((uint)rail_track) == 0);
00222 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00223
00224 return AIObject::DoCommand(tile, tile, GetCurrentRailType() | (FindFirstTrack((::TrackBits)rail_track) << 4), CMD_BUILD_RAILROAD_TRACK);
00225 }
00226
00227 bool AIRail::RemoveRailTrack(TileIndex tile, RailTrack rail_track)
00228 {
00229 EnforcePrecondition(false, ::IsValidTile(tile));
00230 EnforcePrecondition(false, ::IsPlainRailTile(tile) || ::IsLevelCrossingTile(tile));
00231 EnforcePrecondition(false, GetRailTracks(tile) & rail_track);
00232 EnforcePrecondition(false, KillFirstBit((uint)rail_track) == 0);
00233
00234 return AIObject::DoCommand(tile, tile, GetCurrentRailType() | (FindFirstTrack((::TrackBits)rail_track) << 4), CMD_REMOVE_RAILROAD_TRACK);
00235 }
00236
00237 bool AIRail::AreTilesConnected(TileIndex from, TileIndex tile, TileIndex to)
00238 {
00239 if (!IsRailTile(tile)) return false;
00240 if (from == to || AIMap::DistanceManhattan(from, tile) != 1 || AIMap::DistanceManhattan(tile, to) != 1) return false;
00241
00242 if (to < from) ::Swap(from, to);
00243
00244 if (tile - from == 1) {
00245 if (to - tile == 1) return (GetRailTracks(tile) & RAILTRACK_NE_SW) != 0;
00246 if (to - tile == ::MapSizeX()) return (GetRailTracks(tile) & RAILTRACK_NE_SE) != 0;
00247 } else if (tile - from == ::MapSizeX()) {
00248 if (tile - to == 1) return (GetRailTracks(tile) & RAILTRACK_NW_NE) != 0;
00249 if (to - tile == 1) return (GetRailTracks(tile) & RAILTRACK_NW_SW) != 0;
00250 if (to - tile == ::MapSizeX()) return (GetRailTracks(tile) & RAILTRACK_NW_SE) != 0;
00251 } else {
00252 return (GetRailTracks(tile) & RAILTRACK_SW_SE) != 0;
00253 }
00254
00255 NOT_REACHED();
00256 }
00257
00262 static uint32 SimulateDrag(TileIndex from, TileIndex tile, TileIndex *to)
00263 {
00264 int diag_offset = abs(abs((int)::TileX(*to) - (int)::TileX(tile)) - abs((int)::TileY(*to) - (int)::TileY(tile)));
00265 uint32 p2 = AIRail::GetCurrentRailType();
00266 if (::TileY(from) == ::TileY(*to)) {
00267 p2 |= (TRACK_X << 4);
00268 *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00269 } else if (::TileX(from) == ::TileX(*to)) {
00270 p2 |= (TRACK_Y << 4);
00271 *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00272 } else if (::TileY(from) < ::TileY(tile)) {
00273 if (::TileX(*to) < ::TileX(tile)) {
00274 p2 |= (TRACK_UPPER << 4);
00275 } else {
00276 p2 |= (TRACK_LEFT << 4);
00277 }
00278 if (diag_offset) {
00279 *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00280 } else {
00281 *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00282 }
00283 } else if (::TileY(from) > ::TileY(tile)) {
00284 if (::TileX(*to) < ::TileX(tile)) {
00285 p2 |= (TRACK_RIGHT << 4);
00286 } else {
00287 p2 |= (TRACK_LOWER << 4);
00288 }
00289 if (diag_offset) {
00290 *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00291 } else {
00292 *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00293 }
00294 } else if (::TileX(from) < ::TileX(tile)) {
00295 if (::TileY(*to) < ::TileY(tile)) {
00296 p2 |= (TRACK_UPPER << 4);
00297 } else {
00298 p2 |= (TRACK_RIGHT << 4);
00299 }
00300 if (!diag_offset) {
00301 *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00302 } else {
00303 *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00304 }
00305 } else if (::TileX(from) > ::TileX(tile)) {
00306 if (::TileY(*to) < ::TileY(tile)) {
00307 p2 |= (TRACK_LEFT << 4);
00308 } else {
00309 p2 |= (TRACK_LOWER << 4);
00310 }
00311 if (!diag_offset) {
00312 *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00313 } else {
00314 *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00315 }
00316 }
00317 return p2;
00318 }
00319
00320 bool AIRail::BuildRail(TileIndex from, TileIndex tile, TileIndex to)
00321 {
00322 EnforcePrecondition(false, ::IsValidTile(from));
00323 EnforcePrecondition(false, ::IsValidTile(tile));
00324 EnforcePrecondition(false, ::IsValidTile(to));
00325 EnforcePrecondition(false, ::DistanceManhattan(from, tile) == 1);
00326 EnforcePrecondition(false, ::DistanceManhattan(tile, to) >= 1);
00327 EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00328 int diag_offset = abs(abs((int)::TileX(to) - (int)::TileX(tile)) - abs((int)::TileY(to) - (int)::TileY(tile)));
00329 EnforcePrecondition(false, diag_offset <= 1 ||
00330 (::TileX(from) == ::TileX(tile) && ::TileX(tile) == ::TileX(to)) ||
00331 (::TileY(from) == ::TileY(tile) && ::TileY(tile) == ::TileY(to)));
00332
00333 uint32 p2 = SimulateDrag(from, tile, &to);
00334 return AIObject::DoCommand(tile, to, p2, CMD_BUILD_RAILROAD_TRACK);
00335 }
00336
00337 bool AIRail::RemoveRail(TileIndex from, TileIndex tile, TileIndex to)
00338 {
00339 EnforcePrecondition(false, ::IsValidTile(from));
00340 EnforcePrecondition(false, ::IsValidTile(tile));
00341 EnforcePrecondition(false, ::IsValidTile(to));
00342 EnforcePrecondition(false, ::DistanceManhattan(from, tile) == 1);
00343 EnforcePrecondition(false, ::DistanceManhattan(tile, to) >= 1);
00344 int diag_offset = abs(abs((int)::TileX(to) - (int)::TileX(tile)) - abs((int)::TileY(to) - (int)::TileY(tile)));
00345 EnforcePrecondition(false, diag_offset <= 1 ||
00346 (::TileX(from) == ::TileX(tile) && ::TileX(tile) == ::TileX(to)) ||
00347 (::TileY(from) == ::TileY(tile) && ::TileY(tile) == ::TileY(to)));
00348
00349 if (!IsRailTypeAvailable(GetCurrentRailType())) SetCurrentRailType(GetRailType(tile));
00350 uint32 p2 = SimulateDrag(from, tile, &to);
00351 return AIObject::DoCommand(tile, to, p2, CMD_REMOVE_RAILROAD_TRACK);
00352 }
00353
00358 struct AIRailSignalData {
00359 Track track;
00360 Trackdir trackdir;
00361 uint signal_cycles;
00362 };
00363
00364 static const int NUM_TRACK_DIRECTIONS = 3;
00365
00372 static const AIRailSignalData _possible_trackdirs[5][NUM_TRACK_DIRECTIONS] = {
00373 {{TRACK_UPPER, TRACKDIR_UPPER_E, 0}, {TRACK_Y, TRACKDIR_Y_SE, 0}, {TRACK_LEFT, TRACKDIR_LEFT_S, 1}},
00374 {{TRACK_RIGHT, TRACKDIR_RIGHT_S, 1}, {TRACK_X, TRACKDIR_X_SW, 1}, {TRACK_UPPER, TRACKDIR_UPPER_W, 1}},
00375 {{INVALID_TRACK, INVALID_TRACKDIR, 0}, {INVALID_TRACK, INVALID_TRACKDIR, 0}, {INVALID_TRACK, INVALID_TRACKDIR, 0}},
00376 {{TRACK_LOWER, TRACKDIR_LOWER_E, 0}, {TRACK_X, TRACKDIR_X_NE, 0}, {TRACK_LEFT, TRACKDIR_LEFT_N, 0}},
00377 {{TRACK_RIGHT, TRACKDIR_RIGHT_N, 0}, {TRACK_Y, TRACKDIR_Y_NW, 1}, {TRACK_LOWER, TRACKDIR_LOWER_W, 1}}
00378 };
00379
00380 AIRail::SignalType AIRail::GetSignalType(TileIndex tile, TileIndex front)
00381 {
00382 if (AIMap::DistanceManhattan(tile, front) != 1) return SIGNALTYPE_NONE;
00383 if (!::IsTileType(tile, MP_RAILWAY) || !::HasSignals(tile)) return SIGNALTYPE_NONE;
00384
00385 int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00386
00387 for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00388 const Track &track = _possible_trackdirs[data_index][i].track;
00389 if (!(::TrackToTrackBits(track) & GetRailTracks(tile))) continue;
00390 if (!HasSignalOnTrack(tile, track)) continue;
00391 if (!HasSignalOnTrackdir(tile, _possible_trackdirs[data_index][i].trackdir)) continue;
00392 SignalType st = (SignalType)::GetSignalType(tile, track);
00393 if (HasSignalOnTrackdir(tile, ::ReverseTrackdir(_possible_trackdirs[data_index][i].trackdir))) st = (SignalType)(st | SIGNALTYPE_TWOWAY);
00394 return st;
00395 }
00396
00397 return SIGNALTYPE_NONE;
00398 }
00399
00403 static bool IsValidSignalType(int signal_type)
00404 {
00405 if (signal_type < AIRail::SIGNALTYPE_NORMAL || signal_type > AIRail::SIGNALTYPE_COMBO_TWOWAY) return false;
00406 if (signal_type > AIRail::SIGNALTYPE_PBS_ONEWAY && signal_type < AIRail::SIGNALTYPE_NORMAL_TWOWAY) return false;
00407 return true;
00408 }
00409
00410 bool AIRail::BuildSignal(TileIndex tile, TileIndex front, SignalType signal)
00411 {
00412 EnforcePrecondition(false, AIMap::DistanceManhattan(tile, front) == 1)
00413 EnforcePrecondition(false, ::IsPlainRailTile(tile));
00414 EnforcePrecondition(false, ::IsValidSignalType(signal));
00415
00416 Track track = INVALID_TRACK;
00417 uint signal_cycles;
00418
00419 int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00420 for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00421 const Track &t = _possible_trackdirs[data_index][i].track;
00422 if (!(::TrackToTrackBits(t) & GetRailTracks(tile))) continue;
00423 track = t;
00424 signal_cycles = _possible_trackdirs[data_index][i].signal_cycles;
00425 break;
00426 }
00427 EnforcePrecondition(false, track != INVALID_TRACK);
00428
00429 uint p1 = track;
00430 if (signal < SIGNALTYPE_TWOWAY) {
00431 if (signal != SIGNALTYPE_PBS && signal != SIGNALTYPE_PBS_ONEWAY) signal_cycles++;
00432 p1 |= (signal_cycles << 15);
00433 }
00434 p1 |= ((signal >= SIGNALTYPE_TWOWAY ? signal ^ SIGNALTYPE_TWOWAY : signal) << 5);
00435
00436 return AIObject::DoCommand(tile, p1, 0, CMD_BUILD_SIGNALS);
00437 }
00438
00439 bool AIRail::RemoveSignal(TileIndex tile, TileIndex front)
00440 {
00441 EnforcePrecondition(false, AIMap::DistanceManhattan(tile, front) == 1)
00442 EnforcePrecondition(false, GetSignalType(tile, front) != SIGNALTYPE_NONE);
00443
00444 Track track = INVALID_TRACK;
00445 int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00446 for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00447 const Track &t = _possible_trackdirs[data_index][i].track;
00448 if (!(::TrackToTrackBits(t) & GetRailTracks(tile))) continue;
00449 track = t;
00450 break;
00451 }
00452 EnforcePrecondition(false, track != INVALID_TRACK);
00453
00454 return AIObject::DoCommand(tile, track, 0, CMD_REMOVE_SIGNALS);
00455 }