struct Train;

enum VehicleRailFlags {

	VRF_REVERSING         = 0,

	/* used to store if a wagon is powered or not */

	VRF_POWEREDWAGON      = 3,

	/* used to reverse the visible direction of the vehicle */

	VRF_REVERSE_DIRECTION = 4,

	/* used to mark train as lost because PF can't find the route */

	VRF_NO_PATH_TO_DESTINATION = 5,

	/* used to mark that electric train engine is allowed to run on normal rail */

	VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL = 6,

	/* used for vehicle var 0xFE bit 8 (toggled each time the train is reversed, accurate for first vehicle only) */

	VRF_TOGGLE_REVERSE = 7,

	/* used to mark a train that can't get a path reservation */

	VRF_TRAIN_STUCK    = 8,

};

byte FreightWagonMult(CargoID cargo);

void CheckTrainsLengths();

void FreeTrainTrackReservation(const Train *v, TileIndex origin = INVALID_TILE, Trackdir orig_td = INVALID_TRACKDIR);

bool TryPathReserve(Train *v, bool mark_as_stuck = false, bool first_tile_okay = false);

int GetTrainStopLocation(StationID station_id, TileIndex tile, const Train *v, int *station_ahead, int *station_length);

/** Variables that are cached to improve performance and such */

struct TrainCache {

	/* Cached wagon override spritegroup */

	const struct SpriteGroup *cached_override;

	uint16 last_speed; // NOSAVE: only used in UI

	/* cached values, recalculated on load and each time a vehicle is added to/removed from the consist. */

	uint16 cached_total_length; ///< Length of the whole train, valid only for first engine.

	uint8 cached_veh_length;    ///< length of this vehicle in units of 1/8 of normal length, cached because this can be set by a callback

	bool cached_tilt;           ///< train can tilt; feature provides a bonus in curves

	/* cached max. speed / acceleration data */

	uint16 cached_max_speed;    ///< max speed of the consist. (minimum of the max speed of all vehicles in the consist)

	int cached_max_curve_speed; ///< max consist speed limited by curves

	 * bit 0 - 3 = position of effect relative to vehicle. (0 = front, 8 = centre, 15 = rear)

	 * bit 4 - 5 = type of effect. (0 = default for engine class, 1 = steam, 2 = diesel, 3 = electric)

	 * bit     6 = disable visual effect.

	 * bit     7 = disable powered wagons.

	 */

	byte cached_vis_effect;

	byte user_def_data;

	EngineID first_engine;  ///< cached EngineID of the front vehicle. INVALID_ENGINE for the front vehicle itself.

};

/**

 * 'Train' is either a loco or a wagon.

 */

struct Train : public GroundVehicle<Train, VEH_TRAIN> {

	TrainCache tcache;

	/* Link between the two ends of a multiheaded engine */

	Train *other_multiheaded_part;

	uint16 crash_anim_pos;

	uint16 flags;

	TrackBitsByte track;

	RailTypeByte railtype;

	RailTypes compatible_railtypes;

	/** Ticks waiting in front of a signal, ticks being stuck or a counter for forced proceeding through signals. */

	uint16 wait_counter;

	/** We don't want GCC to zero our struct! It already is zeroed and has an index! */

	Train() : GroundVehicle<Train, VEH_TRAIN>() {}

	/** We want to 'destruct' the right class. */

	virtual ~Train() { this->PreDestructor(); }

	friend struct GroundVehicle<Train, VEH_TRAIN>; // GroundVehicle needs to use the acceleration functions defined at Train.

	const char *GetTypeString() const { return "train"; }

	void MarkDirty();

	void UpdateDeltaXY(Direction direction);

	ExpensesType GetExpenseType(bool income) const { return income ? EXPENSES_TRAIN_INC : EXPENSES_TRAIN_RUN; }

	void PlayLeaveStationSound() const;

	bool IsPrimaryVehicle() const { return this->IsFrontEngine(); }

	SpriteID GetImage(Direction direction) const;

	int GetDisplaySpeed() const { return this->tcache.last_speed; }

	int GetDisplayMaxSpeed() const { return this->tcache.cached_max_speed; }

	Money GetRunningCost() const;

	int GetDisplayImageWidth(Point *offset = NULL) const;