ai_rail.cpp

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00001 /* $Id: ai_rail.cpp 21888 2011-01-22 10:33:16Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * 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.
00006  * 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.
00007  * 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/>.
00008  */
00009 
00012 #include "../../stdafx.h"
00013 #include "ai_rail.hpp"
00014 #include "ai_map.hpp"
00015 #include "ai_station.hpp"
00016 #include "ai_industrytype.hpp"
00017 #include "../../debug.h"
00018 #include "../../station_base.h"
00019 #include "../../company_func.h"
00020 #include "../../newgrf.h"
00021 #include "../../newgrf_generic.h"
00022 #include "../../newgrf_station.h"
00023 #include "../../strings_func.h"
00024 
00025 /* static */ char *AIRail::GetName(RailType rail_type)
00026 {
00027   if (!IsRailTypeAvailable(rail_type)) return NULL;
00028 
00029   static const int len = 64;
00030   char *railtype_name = MallocT<char>(len);
00031 
00032   ::GetString(railtype_name, GetRailTypeInfo((::RailType)rail_type)->strings.menu_text, &railtype_name[len - 1]);
00033   return railtype_name;
00034 }
00035 
00036 /* static */ bool AIRail::IsRailTile(TileIndex tile)
00037 {
00038   if (!::IsValidTile(tile)) return false;
00039 
00040   return (::IsTileType(tile, MP_RAILWAY) && !::IsRailDepot(tile)) ||
00041       (::HasStationTileRail(tile) && !::IsStationTileBlocked(tile)) || ::IsLevelCrossingTile(tile);
00042 }
00043 
00044 /* static */ bool AIRail::IsLevelCrossingTile(TileIndex tile)
00045 {
00046   if (!::IsValidTile(tile)) return false;
00047 
00048   return ::IsLevelCrossingTile(tile);
00049 }
00050 
00051 /* static */ bool AIRail::IsRailDepotTile(TileIndex tile)
00052 {
00053   if (!::IsValidTile(tile)) return false;
00054 
00055   return ::IsRailDepotTile(tile);
00056 }
00057 
00058 /* static */ bool AIRail::IsRailStationTile(TileIndex tile)
00059 {
00060   if (!::IsValidTile(tile)) return false;
00061 
00062   return ::IsRailStationTile(tile);
00063 }
00064 
00065 /* static */ bool AIRail::IsRailWaypointTile(TileIndex tile)
00066 {
00067   if (!::IsValidTile(tile)) return false;
00068 
00069   return ::IsRailWaypointTile(tile);
00070 }
00071 
00072 /* static */ bool AIRail::IsRailTypeAvailable(RailType rail_type)
00073 {
00074   if ((::RailType)rail_type < RAILTYPE_BEGIN || (::RailType)rail_type >= RAILTYPE_END) return false;
00075 
00076   return ::HasRailtypeAvail(_current_company, (::RailType)rail_type);
00077 }
00078 
00079 /* static */ AIRail::RailType AIRail::GetCurrentRailType()
00080 {
00081   return (RailType)AIObject::GetRailType();
00082 }
00083 
00084 /* static */ void AIRail::SetCurrentRailType(RailType rail_type)
00085 {
00086   if (!IsRailTypeAvailable(rail_type)) return;
00087 
00088   AIObject::SetRailType((::RailType)rail_type);
00089 }
00090 
00091 /* static */ bool AIRail::TrainCanRunOnRail(AIRail::RailType engine_rail_type, AIRail::RailType track_rail_type)
00092 {
00093   if (!AIRail::IsRailTypeAvailable(engine_rail_type)) return false;
00094   if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;
00095 
00096   return ::IsCompatibleRail((::RailType)engine_rail_type, (::RailType)track_rail_type);
00097 }
00098 
00099 /* static */ bool AIRail::TrainHasPowerOnRail(AIRail::RailType engine_rail_type, AIRail::RailType track_rail_type)
00100 {\
00101   if (!AIRail::IsRailTypeAvailable(engine_rail_type)) return false;
00102   if (!AIRail::IsRailTypeAvailable(track_rail_type)) return false;
00103 
00104   return ::HasPowerOnRail((::RailType)engine_rail_type, (::RailType)track_rail_type);
00105 }
00106 
00107 /* static */ AIRail::RailType AIRail::GetRailType(TileIndex tile)
00108 {
00109   if (!AITile::HasTransportType(tile, AITile::TRANSPORT_RAIL)) return RAILTYPE_INVALID;
00110 
00111   return (RailType)::GetRailType(tile);
00112 }
00113 
00114 /* static */ bool AIRail::ConvertRailType(TileIndex start_tile, TileIndex end_tile, AIRail::RailType convert_to)
00115 {
00116   EnforcePrecondition(false, ::IsValidTile(start_tile));
00117   EnforcePrecondition(false, ::IsValidTile(end_tile));
00118   EnforcePrecondition(false, IsRailTypeAvailable(convert_to));
00119 
00120   return AIObject::DoCommand(start_tile, end_tile, convert_to, CMD_CONVERT_RAIL);
00121 }
00122 
00123 /* static */ TileIndex AIRail::GetRailDepotFrontTile(TileIndex depot)
00124 {
00125   if (!IsRailDepotTile(depot)) return INVALID_TILE;
00126 
00127   return depot + ::TileOffsByDiagDir(::GetRailDepotDirection(depot));
00128 }
00129 
00130 /* static */ AIRail::RailTrack AIRail::GetRailStationDirection(TileIndex tile)
00131 {
00132   if (!IsRailStationTile(tile)) return RAILTRACK_INVALID;
00133 
00134   return (RailTrack)::GetRailStationTrackBits(tile);
00135 }
00136 
00137 /* static */ bool AIRail::BuildRailDepot(TileIndex tile, TileIndex front)
00138 {
00139   EnforcePrecondition(false, tile != front);
00140   EnforcePrecondition(false, ::IsValidTile(tile));
00141   EnforcePrecondition(false, ::IsValidTile(front));
00142   EnforcePrecondition(false, ::TileX(tile) == ::TileX(front) || ::TileY(tile) == ::TileY(front));
00143   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00144 
00145   uint entrance_dir = (::TileX(tile) == ::TileX(front)) ? (::TileY(tile) < ::TileY(front) ? 1 : 3) : (::TileX(tile) < ::TileX(front) ? 2 : 0);
00146 
00147   return AIObject::DoCommand(tile, AIObject::GetRailType(), entrance_dir, CMD_BUILD_TRAIN_DEPOT);
00148 }
00149 
00150 /* static */ bool AIRail::BuildRailStation(TileIndex tile, RailTrack direction, uint num_platforms, uint platform_length, StationID station_id)
00151 {
00152   EnforcePrecondition(false, ::IsValidTile(tile));
00153   EnforcePrecondition(false, direction == RAILTRACK_NW_SE || direction == RAILTRACK_NE_SW);
00154   EnforcePrecondition(false, num_platforms > 0 && num_platforms <= 0xFF);
00155   EnforcePrecondition(false, platform_length > 0 && platform_length <= 0xFF);
00156   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00157   EnforcePrecondition(false, station_id == AIStation::STATION_NEW || station_id == AIStation::STATION_JOIN_ADJACENT || AIStation::IsValidStation(station_id));
00158 
00159   uint32 p1 = GetCurrentRailType() | (platform_length << 16) | (num_platforms << 8);
00160   if (direction == RAILTRACK_NW_SE) p1 |= (1 << 4);
00161   if (station_id != AIStation::STATION_JOIN_ADJACENT) p1 |= (1 << 24);
00162   return AIObject::DoCommand(tile, p1, (AIStation::IsValidStation(station_id) ? station_id : INVALID_STATION) << 16, CMD_BUILD_RAIL_STATION);
00163 }
00164 
00165 /* static */ 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)
00166 {
00167   EnforcePrecondition(false, ::IsValidTile(tile));
00168   EnforcePrecondition(false, direction == RAILTRACK_NW_SE || direction == RAILTRACK_NE_SW);
00169   EnforcePrecondition(false, num_platforms > 0 && num_platforms <= 0xFF);
00170   EnforcePrecondition(false, platform_length > 0 && platform_length <= 0xFF);
00171   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00172   EnforcePrecondition(false, station_id == AIStation::STATION_NEW || station_id == AIStation::STATION_JOIN_ADJACENT || AIStation::IsValidStation(station_id));
00173   EnforcePrecondition(false, source_industry == AIIndustryType::INDUSTRYTYPE_UNKNOWN || source_industry == AIIndustryType::INDUSTRYTYPE_TOWN || AIIndustryType::IsValidIndustryType(source_industry));
00174   EnforcePrecondition(false, goal_industry   == AIIndustryType::INDUSTRYTYPE_UNKNOWN || goal_industry   == AIIndustryType::INDUSTRYTYPE_TOWN || AIIndustryType::IsValidIndustryType(goal_industry));
00175 
00176   uint32 p1 = GetCurrentRailType() | (platform_length << 16) | (num_platforms << 8);
00177   if (direction == RAILTRACK_NW_SE) p1 |= 1 << 4;
00178   if (station_id != AIStation::STATION_JOIN_ADJACENT) p1 |= (1 << 24);
00179 
00180   const GRFFile *file;
00181   uint16 res = GetAiPurchaseCallbackResult(GSF_STATIONS, 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);
00182   uint32 p2 = (AIStation::IsValidStation(station_id) ? station_id : INVALID_STATION) << 16;
00183   if (res != CALLBACK_FAILED) {
00184     int index = 0;
00185     const StationSpec *spec = StationClass::GetByGrf(file->grfid, res, &index);
00186     if (spec == NULL) {
00187       DEBUG(grf, 1, "%s returned an invalid station ID for 'AI construction/purchase selection (18)' callback", file->filename);
00188     } else {
00189       p2 |= spec->cls_id | index << 8;
00190     }
00191 
00192   }
00193   return AIObject::DoCommand(tile, p1, p2, CMD_BUILD_RAIL_STATION);
00194 }
00195 
00196 /* static */ bool AIRail::BuildRailWaypoint(TileIndex tile)
00197 {
00198   EnforcePrecondition(false, ::IsValidTile(tile));
00199   EnforcePrecondition(false, IsRailTile(tile));
00200   EnforcePrecondition(false, GetRailTracks(tile) == RAILTRACK_NE_SW || GetRailTracks(tile) == RAILTRACK_NW_SE);
00201   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00202 
00203   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);
00204 }
00205 
00206 /* static */ bool AIRail::RemoveRailWaypointTileRectangle(TileIndex tile, TileIndex tile2, bool keep_rail)
00207 {
00208   EnforcePrecondition(false, ::IsValidTile(tile));
00209   EnforcePrecondition(false, ::IsValidTile(tile2));
00210 
00211   return AIObject::DoCommand(tile, tile2, keep_rail ? 1 : 0, CMD_REMOVE_FROM_RAIL_WAYPOINT);
00212 }
00213 
00214 /* static */ bool AIRail::RemoveRailStationTileRectangle(TileIndex tile, TileIndex tile2, bool keep_rail)
00215 {
00216   EnforcePrecondition(false, ::IsValidTile(tile));
00217   EnforcePrecondition(false, ::IsValidTile(tile2));
00218 
00219   return AIObject::DoCommand(tile, tile2, keep_rail ? 1 : 0, CMD_REMOVE_FROM_RAIL_STATION);
00220 }
00221 
00222 /* static */ uint AIRail::GetRailTracks(TileIndex tile)
00223 {
00224   if (!IsRailTile(tile)) return RAILTRACK_INVALID;
00225 
00226   if (IsRailStationTile(tile) || IsRailWaypointTile(tile)) return ::TrackToTrackBits(::GetRailStationTrack(tile));
00227   if (IsLevelCrossingTile(tile)) return ::GetCrossingRailBits(tile);
00228   if (IsRailDepotTile(tile)) return ::TRACK_BIT_NONE;
00229   return ::GetTrackBits(tile);
00230 }
00231 
00232 /* static */ bool AIRail::BuildRailTrack(TileIndex tile, RailTrack rail_track)
00233 {
00234   EnforcePrecondition(false, ::IsValidTile(tile));
00235   EnforcePrecondition(false, rail_track != 0);
00236   EnforcePrecondition(false, (rail_track & ~::TRACK_BIT_ALL) == 0);
00237   EnforcePrecondition(false, KillFirstBit((uint)rail_track) == 0);
00238   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
00239 
00240   return AIObject::DoCommand(tile, tile, GetCurrentRailType() | (FindFirstTrack((::TrackBits)rail_track) << 4), CMD_BUILD_RAILROAD_TRACK);
00241 }
00242 
00243 /* static */ bool AIRail::RemoveRailTrack(TileIndex tile, RailTrack rail_track)
00244 {
00245   EnforcePrecondition(false, ::IsValidTile(tile));
00246   EnforcePrecondition(false, ::IsPlainRailTile(tile) || ::IsLevelCrossingTile(tile));
00247   EnforcePrecondition(false, GetRailTracks(tile) & rail_track);
00248   EnforcePrecondition(false, KillFirstBit((uint)rail_track) == 0);
00249 
00250   return AIObject::DoCommand(tile, tile, GetCurrentRailType() | (FindFirstTrack((::TrackBits)rail_track) << 4), CMD_REMOVE_RAILROAD_TRACK);
00251 }
00252 
00253 /* static */ bool AIRail::AreTilesConnected(TileIndex from, TileIndex tile, TileIndex to)
00254 {
00255   if (!IsRailTile(tile)) return false;
00256   if (from == to || AIMap::DistanceManhattan(from, tile) != 1 || AIMap::DistanceManhattan(tile, to) != 1) return false;
00257 
00258   if (to < from) ::Swap(from, to);
00259 
00260   if (tile - from == 1) {
00261     if (to - tile == 1) return (GetRailTracks(tile) & RAILTRACK_NE_SW) != 0;
00262     if (to - tile == ::MapSizeX()) return (GetRailTracks(tile) & RAILTRACK_NE_SE) != 0;
00263   } else if (tile - from == ::MapSizeX()) {
00264     if (tile - to == 1) return (GetRailTracks(tile) & RAILTRACK_NW_NE) != 0;
00265     if (to - tile == 1) return (GetRailTracks(tile) & RAILTRACK_NW_SW) != 0;
00266     if (to - tile == ::MapSizeX()) return (GetRailTracks(tile) & RAILTRACK_NW_SE) != 0;
00267   } else {
00268     return (GetRailTracks(tile) & RAILTRACK_SW_SE) != 0;
00269   }
00270 
00271   NOT_REACHED();
00272 }
00273 
00278 static uint32 SimulateDrag(TileIndex from, TileIndex tile, TileIndex *to)
00279 {
00280   int diag_offset = abs(abs((int)::TileX(*to) - (int)::TileX(tile)) - abs((int)::TileY(*to) - (int)::TileY(tile)));
00281   uint32 p2 = AIRail::GetCurrentRailType();
00282   if (::TileY(from) == ::TileY(*to)) {
00283     p2 |= (TRACK_X << 4);
00284     *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00285   } else if (::TileX(from) == ::TileX(*to)) {
00286     p2 |= (TRACK_Y << 4);
00287     *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00288   } else if (::TileY(from) < ::TileY(tile)) {
00289     if (::TileX(*to) < ::TileX(tile)) {
00290       p2 |= (TRACK_UPPER << 4);
00291     } else {
00292       p2 |= (TRACK_LEFT << 4);
00293     }
00294     if (diag_offset) {
00295       *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00296     } else {
00297       *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00298     }
00299   } else if (::TileY(from) > ::TileY(tile)) {
00300     if (::TileX(*to) < ::TileX(tile)) {
00301       p2 |= (TRACK_RIGHT << 4);
00302     } else {
00303       p2 |= (TRACK_LOWER << 4);
00304     }
00305     if (diag_offset) {
00306       *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00307     } else {
00308       *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00309     }
00310   } else if (::TileX(from) < ::TileX(tile)) {
00311     if (::TileY(*to) < ::TileY(tile)) {
00312       p2 |= (TRACK_UPPER << 4);
00313     } else {
00314       p2 |= (TRACK_RIGHT << 4);
00315     }
00316     if (!diag_offset) {
00317       *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00318     } else {
00319       *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00320     }
00321   } else if (::TileX(from) > ::TileX(tile)) {
00322     if (::TileY(*to) < ::TileY(tile)) {
00323       p2 |= (TRACK_LEFT << 4);
00324     } else {
00325       p2 |= (TRACK_LOWER << 4);
00326     }
00327     if (!diag_offset) {
00328       *to -= Clamp((int)::TileX(*to) - (int)::TileX(tile), -1, 1);
00329     } else {
00330       *to -= ::MapSizeX() * Clamp((int)::TileY(*to) - (int)::TileY(tile), -1, 1);
00331     }
00332   }
00333   return p2;
00334 }
00335 
00336 /* static */ bool AIRail::BuildRail(TileIndex from, TileIndex tile, TileIndex to)
00337 {
00338   EnforcePrecondition(false, ::IsValidTile(from));
00339   EnforcePrecondition(false, ::IsValidTile(tile));
00340   EnforcePrecondition(false, ::IsValidTile(to));
00341   EnforcePrecondition(false, ::DistanceManhattan(from, tile) == 1);
00342   EnforcePrecondition(false, ::DistanceManhattan(tile, to) >= 1);
00343   EnforcePrecondition(false, IsRailTypeAvailable(GetCurrentRailType()));
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   uint32 p2 = SimulateDrag(from, tile, &to) | 1 << 8;
00350   return AIObject::DoCommand(tile, to, p2, CMD_BUILD_RAILROAD_TRACK);
00351 }
00352 
00353 /* static */ bool AIRail::RemoveRail(TileIndex from, TileIndex tile, TileIndex to)
00354 {
00355   EnforcePrecondition(false, ::IsValidTile(from));
00356   EnforcePrecondition(false, ::IsValidTile(tile));
00357   EnforcePrecondition(false, ::IsValidTile(to));
00358   EnforcePrecondition(false, ::DistanceManhattan(from, tile) == 1);
00359   EnforcePrecondition(false, ::DistanceManhattan(tile, to) >= 1);
00360   int diag_offset = abs(abs((int)::TileX(to) - (int)::TileX(tile)) - abs((int)::TileY(to) - (int)::TileY(tile)));
00361   EnforcePrecondition(false, diag_offset <= 1 ||
00362       (::TileX(from) == ::TileX(tile) && ::TileX(tile) == ::TileX(to)) ||
00363       (::TileY(from) == ::TileY(tile) && ::TileY(tile) == ::TileY(to)));
00364 
00365   if (!IsRailTypeAvailable(GetCurrentRailType())) SetCurrentRailType(GetRailType(tile));
00366   uint32 p2 = SimulateDrag(from, tile, &to);
00367   return AIObject::DoCommand(tile, to, p2, CMD_REMOVE_RAILROAD_TRACK);
00368 }
00369 
00374 struct AIRailSignalData {
00375   Track track;        
00376   Trackdir trackdir;  
00377   uint signal_cycles; 
00378 };
00379 
00380 static const int NUM_TRACK_DIRECTIONS = 3; 
00381 
00388 static const AIRailSignalData _possible_trackdirs[5][NUM_TRACK_DIRECTIONS] = {
00389   {{TRACK_UPPER,   TRACKDIR_UPPER_E, 0}, {TRACK_Y,       TRACKDIR_Y_SE,    0}, {TRACK_LEFT,    TRACKDIR_LEFT_S,  1}},
00390   {{TRACK_RIGHT,   TRACKDIR_RIGHT_S, 1}, {TRACK_X,       TRACKDIR_X_SW,    1}, {TRACK_UPPER,   TRACKDIR_UPPER_W, 1}},
00391   {{INVALID_TRACK, INVALID_TRACKDIR, 0}, {INVALID_TRACK, INVALID_TRACKDIR, 0}, {INVALID_TRACK, INVALID_TRACKDIR, 0}},
00392   {{TRACK_LOWER,   TRACKDIR_LOWER_E, 0}, {TRACK_X,       TRACKDIR_X_NE,    0}, {TRACK_LEFT,    TRACKDIR_LEFT_N,  0}},
00393   {{TRACK_RIGHT,   TRACKDIR_RIGHT_N, 0}, {TRACK_Y,       TRACKDIR_Y_NW,    1}, {TRACK_LOWER,   TRACKDIR_LOWER_W, 1}}
00394 };
00395 
00396 /* static */ AIRail::SignalType AIRail::GetSignalType(TileIndex tile, TileIndex front)
00397 {
00398   if (AIMap::DistanceManhattan(tile, front) != 1) return SIGNALTYPE_NONE;
00399   if (!::IsTileType(tile, MP_RAILWAY) || !::HasSignals(tile)) return SIGNALTYPE_NONE;
00400 
00401   int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00402 
00403   for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00404     const Track &track = _possible_trackdirs[data_index][i].track;
00405     if (!(::TrackToTrackBits(track) & GetRailTracks(tile))) continue;
00406     if (!HasSignalOnTrack(tile, track)) continue;
00407     if (!HasSignalOnTrackdir(tile, _possible_trackdirs[data_index][i].trackdir)) continue;
00408     SignalType st = (SignalType)::GetSignalType(tile, track);
00409     if (HasSignalOnTrackdir(tile, ::ReverseTrackdir(_possible_trackdirs[data_index][i].trackdir))) st = (SignalType)(st | SIGNALTYPE_TWOWAY);
00410     return st;
00411   }
00412 
00413   return SIGNALTYPE_NONE;
00414 }
00415 
00419 static bool IsValidSignalType(int signal_type)
00420 {
00421   if (signal_type < AIRail::SIGNALTYPE_NORMAL || signal_type > AIRail::SIGNALTYPE_COMBO_TWOWAY) return false;
00422   if (signal_type > AIRail::SIGNALTYPE_PBS_ONEWAY && signal_type < AIRail::SIGNALTYPE_NORMAL_TWOWAY) return false;
00423   return true;
00424 }
00425 
00426 /* static */ bool AIRail::BuildSignal(TileIndex tile, TileIndex front, SignalType signal)
00427 {
00428   EnforcePrecondition(false, AIMap::DistanceManhattan(tile, front) == 1)
00429   EnforcePrecondition(false, ::IsPlainRailTile(tile));
00430   EnforcePrecondition(false, ::IsValidSignalType(signal));
00431 
00432   Track track = INVALID_TRACK;
00433   uint signal_cycles;
00434 
00435   int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00436   for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00437     const Track &t = _possible_trackdirs[data_index][i].track;
00438     if (!(::TrackToTrackBits(t) & GetRailTracks(tile))) continue;
00439     track = t;
00440     signal_cycles = _possible_trackdirs[data_index][i].signal_cycles;
00441     break;
00442   }
00443   EnforcePrecondition(false, track != INVALID_TRACK);
00444 
00445   uint p1 = track;
00446   if (signal < SIGNALTYPE_TWOWAY) {
00447     if (signal != SIGNALTYPE_PBS && signal != SIGNALTYPE_PBS_ONEWAY) signal_cycles++;
00448     p1 |= (signal_cycles << 15);
00449   }
00450   p1 |= ((signal >= SIGNALTYPE_TWOWAY ? signal ^ SIGNALTYPE_TWOWAY : signal) << 5);
00451 
00452   return AIObject::DoCommand(tile, p1, 0, CMD_BUILD_SIGNALS);
00453 }
00454 
00455 /* static */ bool AIRail::RemoveSignal(TileIndex tile, TileIndex front)
00456 {
00457   EnforcePrecondition(false, AIMap::DistanceManhattan(tile, front) == 1)
00458   EnforcePrecondition(false, GetSignalType(tile, front) != SIGNALTYPE_NONE);
00459 
00460   Track track = INVALID_TRACK;
00461   int data_index = 2 + (::TileX(front) - ::TileX(tile)) + 2 * (::TileY(front) - ::TileY(tile));
00462   for (int i = 0; i < NUM_TRACK_DIRECTIONS; i++) {
00463     const Track &t = _possible_trackdirs[data_index][i].track;
00464     if (!(::TrackToTrackBits(t) & GetRailTracks(tile))) continue;
00465     track = t;
00466     break;
00467   }
00468   EnforcePrecondition(false, track != INVALID_TRACK);
00469 
00470   return AIObject::DoCommand(tile, track, 0, CMD_REMOVE_SIGNALS);
00471 }
00472 
00473 /* static */ Money AIRail::GetBuildCost(RailType railtype, BuildType build_type)
00474 {
00475   if (!AIRail::IsRailTypeAvailable(railtype)) return -1;
00476 
00477   switch (build_type) {
00478     case BT_TRACK:    return ::RailBuildCost((::RailType)railtype);
00479     case BT_SIGNAL:   return ::GetPrice(PR_BUILD_SIGNALS, 1, NULL);
00480     case BT_DEPOT:    return ::GetPrice(PR_BUILD_DEPOT_TRAIN, 1, NULL);
00481     case BT_STATION:  return ::GetPrice(PR_BUILD_STATION_RAIL, 1, NULL) + ::GetPrice(PR_BUILD_STATION_RAIL_LENGTH, 1, NULL);
00482     case BT_WAYPOINT: return ::GetPrice(PR_BUILD_WAYPOINT_RAIL, 1, NULL);
00483     default: return -1;
00484   }
00485 }
00486 
00487 /* static */ int32 AIRail::GetMaxSpeed(RailType railtype)
00488 {
00489   if (!AIRail::IsRailTypeAvailable(railtype)) return -1;
00490 
00491   return ::GetRailTypeInfo((::RailType)railtype)->max_speed;
00492 }