src/train.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file train.h Base for the train class. */
   9
  10 #ifndef TRAIN_H
  11 #define TRAIN_H
  12
  13 #include "core/enum_type.hpp"
  14
  15 #include "newgrf_engine.h"
  16 #include "cargotype.h"
  17 #include "rail.h"
  18 #include "engine_base.h"
  19 #include "rail_map.h"
  20 #include "ground_vehicle.hpp"
  21
  22 struct Train;
  23
  24 /** Rail vehicle flags. */
  25 enum VehicleRailFlags {
  26         VRF_REVERSING                     = 0,
  27         VRF_POWEREDWAGON                  = 3, ///< Wagon is powered.
  28         VRF_REVERSE_DIRECTION             = 4, ///< Reverse the visible direction of the vehicle.
  29
  30         VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL = 6, ///< Electric train engine is allowed to run on normal rail. */
  31         VRF_TOGGLE_REVERSE                = 7, ///< Used for vehicle var 0xFE bit 8 (toggled each time the train is reversed, accurate for first vehicle only).
  32         VRF_TRAIN_STUCK                   = 8, ///< Train can't get a path reservation.
  33         VRF_LEAVING_STATION               = 9, ///< Train is just leaving a station.
  34 };
  35
  36 /** Modes for ignoring signals. */
  37 enum TrainForceProceeding : byte {
  38         TFP_NONE   = 0,    ///< Normal operation.
  39         TFP_STUCK  = 1,    ///< Proceed till next signal, but ignore being stuck till then. This includes force leaving depots.
  40         TFP_SIGNAL = 2,    ///< Ignore next signal, after the signal ignore being stuck.
  41 };
  42
  43 /** Flags for Train::ConsistChanged */
  44 enum ConsistChangeFlags {
  45         CCF_LENGTH     = 0x01,     ///< Allow vehicles to change length.
  46         CCF_CAPACITY   = 0x02,     ///< Allow vehicles to change capacity.
  47
  48         CCF_TRACK      = 0,                          ///< Valid changes while vehicle is driving, and possibly changing tracks.
  49         CCF_LOADUNLOAD = 0,                          ///< Valid changes while vehicle is loading/unloading.
  50         CCF_AUTOREFIT  = CCF_CAPACITY,               ///< Valid changes for autorefitting in stations.
  51         CCF_REFIT      = CCF_LENGTH | CCF_CAPACITY,  ///< Valid changes for refitting in a depot.
  52         CCF_ARRANGE    = CCF_LENGTH | CCF_CAPACITY,  ///< Valid changes for arranging the consist in a depot.
  53         CCF_SAVELOAD   = CCF_LENGTH,                 ///< Valid changes when loading a savegame. (Everything that is not stored in the save.)
  54 };
  55 DECLARE_ENUM_AS_BIT_SET(ConsistChangeFlags)
  56
  57 byte FreightWagonMult(CargoID cargo);
  58
  59 void CheckTrainsLengths();
  60
  61 void FreeTrainTrackReservation(const Train *v);
  62 bool TryPathReserve(Train *v, bool mark_as_stuck = false, bool first_tile_okay = false);
  63
  64 int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length);
  65
  66 void GetTrainSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type);
  67
  68 /** Variables that are cached to improve performance and such */
  69 struct TrainCache {
  70         /* Cached wagon override spritegroup */
  71         const struct SpriteGroup *cached_override;
  72
  73         /* cached values, recalculated on load and each time a vehicle is added to/removed from the consist. */
  74         bool cached_tilt;           ///< train can tilt; feature provides a bonus in curves
  75
  76         byte user_def_data;         ///< Cached property 0x25. Can be set by Callback 0x36.
  77
  78         /* cached max. speed / acceleration data */
  79         int cached_max_curve_speed; ///< max consist speed limited by curves
  80 };
  81
  82 /**
  83  * 'Train' is either a loco or a wagon.
  84  */
  85 struct Train FINAL : public GroundVehicle<Train, VEH_TRAIN> {
  86         TrainCache tcache;
  87
  88         /* Link between the two ends of a multiheaded engine */
  89         Train *other_multiheaded_part;
  90
  91         uint16 crash_anim_pos; ///< Crash animation counter.
  92
  93         uint16 flags;
  94         TrackBits track;
  95         TrainForceProceeding force_proceed;
  96         RailType railtype;
  97         RailTypes compatible_railtypes;
  98
  99         /** Ticks waiting in front of a signal, ticks being stuck or a counter for forced proceeding through signals. */
 100         uint16 wait_counter;
 101
 102         /** We don't want GCC to zero our struct! It already is zeroed and has an index! */
 103         Train() : GroundVehicleBase() {}
 104         /** We want to 'destruct' the right class. */
 105         virtual ~Train() { this->PreDestructor(); }
 106
 107         friend struct GroundVehicle<Train, VEH_TRAIN>; // GroundVehicle needs to use the acceleration functions defined at Train.
 108
 109         void MarkDirty();
 110         void UpdateDeltaXY();
 111         ExpensesType GetExpenseType(bool income) const { return income ? EXPENSES_TRAIN_INC : EXPENSES_TRAIN_RUN; }
 112         void PlayLeaveStationSound() const;
 113         bool IsPrimaryVehicle() const { return this->IsFrontEngine(); }
 114         void GetImage(Direction direction, EngineImageType image_type, VehicleSpriteSeq *result) const;
 115         int GetDisplaySpeed() const { return this->gcache.last_speed; }
 116         int GetDisplayMaxSpeed() const { return this->vcache.cached_max_speed; }
 117         Money GetRunningCost() const;
 118         int GetDisplayImageWidth(Point *offset = nullptr) const;
 119         bool IsInDepot() const { return this->track == TRACK_BIT_DEPOT; }
 120         bool Tick();
 121         void OnNewDay();
 122         uint Crash(bool flooded = false);
 123         Trackdir GetVehicleTrackdir() const;
 124         TileIndex GetOrderStationLocation(StationID station);
 125         bool FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse);
 126
 127         void ReserveTrackUnderConsist() const;
 128
 129         int GetCurveSpeedLimit() const;
 130
 131         void ConsistChanged(ConsistChangeFlags allowed_changes);
 132
 133         int UpdateSpeed();
 134
 135         void UpdateAcceleration();
 136
 137         int GetCurrentMaxSpeed() const;
 138
 139         /**
 140          * Get the next real (non-articulated part and non rear part of dualheaded engine) vehicle in the consist.
 141          * @return Next vehicle in the consist.
 142          */
 143         inline Train *GetNextUnit() const
 144         {
 145                 Train *v = this->GetNextVehicle();
 146                 if (v != nullptr && v->IsRearDualheaded()) v = v->GetNextVehicle();
 147
 148                 return v;
 149         }
 150
 151         /**
 152          * Get the previous real (non-articulated part and non rear part of dualheaded engine) vehicle in the consist.
 153          * @return Previous vehicle in the consist.
 154          */
 155         inline Train *GetPrevUnit()
 156         {
 157                 Train *v = this->GetPrevVehicle();
 158                 if (v != nullptr && v->IsRearDualheaded()) v = v->GetPrevVehicle();
 159
 160                 return v;
 161         }
 162
 163         /**
 164          * Calculate the offset from this vehicle's center to the following center taking the vehicle lengths into account.
 165          * @return Offset from center to center.
 166          */
 167         int CalcNextVehicleOffset() const
 168         {
 169                 /* For vehicles with odd lengths the part before the center will be one unit
 170                  * longer than the part after the center. This means we have to round up the
 171                  * length of the next vehicle but may not round the length of the current
 172                  * vehicle. */
 173                 return this->gcache.cached_veh_length / 2 + (this->Next() != nullptr ? this->Next()->gcache.cached_veh_length + 1 : 0) / 2;
 174         }
 175
 176 protected: // These functions should not be called outside acceleration code.
 177
 178         /**
 179          * Allows to know the power value that this vehicle will use.
 180          * @return Power value from the engine in HP, or zero if the vehicle is not powered.
 181          */
 182         inline uint16 GetPower() const
 183         {
 184                 /* Power is not added for articulated parts */
 185                 if (!this->IsArticulatedPart() && HasPowerOnRail(this->railtype, GetRailType(this->tile))) {
 186                         uint16 power = GetVehicleProperty(this, PROP_TRAIN_POWER, RailVehInfo(this->engine_type)->power);
 187                         /* Halve power for multiheaded parts */
 188                         if (this->IsMultiheaded()) power /= 2;
 189                         return power;
 190                 }
 191
 192                 return 0;
 193         }
 194
 195         /**
 196          * Returns a value if this articulated part is powered.
 197          * @return Power value from the articulated part in HP, or zero if it is not powered.
 198          */
 199         inline uint16 GetPoweredPartPower(const Train *head) const
 200         {
 201                 /* For powered wagons the engine defines the type of engine (i.e. railtype) */
 202                 if (HasBit(this->flags, VRF_POWEREDWAGON) && HasPowerOnRail(head->railtype, GetRailType(this->tile))) {
 203                         return RailVehInfo(this->gcache.first_engine)->pow_wag_power;
 204                 }
 205
 206                 return 0;
 207         }
 208
 209         /**
 210          * Allows to know the weight value that this vehicle will use.
 211          * @return Weight value from the engine in tonnes.
 212          */
 213         inline uint16 GetWeight() const
 214         {
 215                 uint16 weight = (CargoSpec::Get(this->cargo_type)->weight * this->cargo.StoredCount() * FreightWagonMult(this->cargo_type)) / 16;
 216
 217                 /* Vehicle weight is not added for articulated parts. */
 218                 if (!this->IsArticulatedPart()) {
 219                         weight += GetVehicleProperty(this, PROP_TRAIN_WEIGHT, RailVehInfo(this->engine_type)->weight);
 220                 }
 221
 222                 /* Powered wagons have extra weight added. */
 223                 if (HasBit(this->flags, VRF_POWEREDWAGON)) {
 224                         weight += RailVehInfo(this->gcache.first_engine)->pow_wag_weight;
 225                 }
 226
 227                 return weight;
 228         }
 229
 230         /**
 231          * Allows to know the tractive effort value that this vehicle will use.
 232          * @return Tractive effort value from the engine.
 233          */
 234         inline byte GetTractiveEffort() const
 235         {
 236                 return GetVehicleProperty(this, PROP_TRAIN_TRACTIVE_EFFORT, RailVehInfo(this->engine_type)->tractive_effort);
 237         }
 238
 239         /**
 240          * Gets the area used for calculating air drag.
 241          * @return Area of the engine in m^2.
 242          */
 243         inline byte GetAirDragArea() const
 244         {
 245                 /* Air drag is higher in tunnels due to the limited cross-section. */
 246                 return (this->track == TRACK_BIT_WORMHOLE && this->vehstatus & VS_HIDDEN) ? 28 : 14;
 247         }
 248
 249         /**
 250          * Gets the air drag coefficient of this vehicle.
 251          * @return Air drag value from the engine.
 252          */
 253         inline byte GetAirDrag() const
 254         {
 255                 return RailVehInfo(this->engine_type)->air_drag;
 256         }
 257
 258         /**
 259          * Checks the current acceleration status of this vehicle.
 260          * @return Acceleration status.
 261          */
 262         inline AccelStatus GetAccelerationStatus() const
 263         {
 264                 return (this->vehstatus & VS_STOPPED) || HasBit(this->flags, VRF_REVERSING) || HasBit(this->flags, VRF_TRAIN_STUCK) ? AS_BRAKE : AS_ACCEL;
 265         }
 266
 267         /**
 268          * Calculates the current speed of this vehicle.
 269          * @return Current speed in km/h-ish.
 270          */
 271         inline uint16 GetCurrentSpeed() const
 272         {
 273                 return this->cur_speed;
 274         }
 275
 276         /**
 277          * Returns the rolling friction coefficient of this vehicle.
 278          * @return Rolling friction coefficient in [1e-4].
 279          */
 280         inline uint32 GetRollingFriction() const
 281         {
 282                 /* Rolling friction for steel on steel is between 0.1% and 0.2%.
 283                  * The friction coefficient increases with speed in a way that
 284                  * it doubles at 512 km/h, triples at 1024 km/h and so on. */
 285                 return 15 * (512 + this->GetCurrentSpeed()) / 512;
 286         }
 287
 288         /**
 289          * Allows to know the acceleration type of a vehicle.
 290          * @return Acceleration type of the vehicle.
 291          */
 292         inline int GetAccelerationType() const
 293         {
 294                 return GetRailTypeInfo(this->railtype)->acceleration_type;
 295         }
 296
 297         /**
 298          * Returns the slope steepness used by this vehicle.
 299          * @return Slope steepness used by the vehicle.
 300          */
 301         inline uint32 GetSlopeSteepness() const
 302         {
 303                 return _settings_game.vehicle.train_slope_steepness;
 304         }
 305
 306         /**
 307          * Gets the maximum speed allowed by the track for this vehicle.
 308          * @return Maximum speed allowed.
 309          */
 310         inline uint16 GetMaxTrackSpeed() const
 311         {
 312                 return GetRailTypeInfo(GetRailType(this->tile))->max_speed;
 313         }
 314
 315         /**
 316          * Checks if the vehicle is at a tile that can be sloped.
 317          * @return True if the tile can be sloped.
 318          */
 319         inline bool TileMayHaveSlopedTrack() const
 320         {
 321                 /* Any track that isn't TRACK_BIT_X or TRACK_BIT_Y cannot be sloped. */
 322                 return this->track == TRACK_BIT_X || this->track == TRACK_BIT_Y;
 323         }
 324
 325         /**
 326          * Trains can always use the faster algorithm because they
 327          * have always the same direction as the track under them.
 328          * @return false
 329          */
 330         inline bool HasToUseGetSlopePixelZ()
 331         {
 332                 return false;
 333         }
 334 };
 335
 336 #endif /* TRAIN_H */