Rearrange storage of reserved tracks for railway tiles

[openttd/fttd.git] / src / vehicle.cpp

/* $Id$ */

/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */

/** @file vehicle.cpp Base implementations of all vehicles. */

#include "stdafx.h"
#include "error.h"
#include "roadveh.h"
#include "ship.h"
#include "spritecache.h"
#include "timetable.h"
#include "viewport_func.h"
#include "news_func.h"
#include "command_func.h"
#include "company_func.h"
#include "train.h"
#include "aircraft.h"
#include "newgrf_debug.h"
#include "newgrf_sound.h"
#include "newgrf_station.h"
#include "group_gui.h"
#include "strings_func.h"
#include "zoom_func.h"
#include "date_func.h"
#include "vehicle_func.h"
#include "autoreplace_func.h"
#include "autoreplace_gui.h"
#include "station_base.h"
#include "ai/ai.hpp"
#include "depot_func.h"
#include "network/network.h"
#include "core/pool_func.hpp"
#include "economy_base.h"
#include "articulated_vehicles.h"
#include "roadstop_base.h"
#include "core/random_func.hpp"
#include "core/backup_type.hpp"
#include "order_backup.h"
#include "sound_func.h"
#include "effectvehicle_func.h"
#include "effectvehicle_base.h"
#include "vehiclelist.h"
#include "map/tunnel.h"
#include "map/slope.h"
#include "gamelog.h"
#include "signal_func.h"
#include "linkgraph/linkgraph.h"
#include "linkgraph/refresh.h"

#include "table/strings.h"


VehicleID _new_vehicle_id;
uint16 _returned_refit_capacity;      ///< Stores the capacity after a refit operation.
uint16 _returned_mail_refit_capacity; ///< Stores the mail capacity after a refit operation (Aircraft only).


/** The pool with all our precious vehicles. */
VehiclePool _vehicle_pool("Vehicle");
INSTANTIATE_POOL_METHODS(Vehicle)

/**
 * Function to tell if a vehicle needs to be autorenewed
 * @param *c The vehicle owner
 * @param use_renew_setting Should the company renew setting be considered?
 * @return true if the vehicle is old enough for replacement
 */
bool Vehicle::NeedsAutorenewing(const Company *c, bool use_renew_setting) const
{
        /* We can always generate the Company pointer when we have the vehicle.
         * However this takes time and since the Company pointer is often present
         * when this function is called then it's faster to pass the pointer as an
         * argument rather than finding it again. */
        assert(c == Company::Get(this->owner));

        if (use_renew_setting && !c->settings.engine_renew) return false;
        if (this->age - this->max_age < (c->settings.engine_renew_months * 30)) return false;

        /* Only engines need renewing */
        if (this->type == VEH_TRAIN && !Train::From(this)->IsEngine()) return false;

        return true;
}

/**
 * Service a vehicle and all subsequent vehicles in the consist
 *
 * @param *v The vehicle or vehicle chain being serviced
 */
void VehicleServiceInDepot(Vehicle *v)
{
        assert(v != NULL);
        SetWindowDirty(WC_VEHICLE_DETAILS, v->index); // ensure that last service date and reliability are updated

        do {
                v->date_of_last_service = _date;
                v->breakdowns_since_last_service = 0;
                v->reliability = v->GetEngine()->reliability;
                /* Prevent vehicles from breaking down directly after exiting the depot. */
                v->breakdown_chance /= 4;
                v = v->Next();
        } while (v != NULL && v->HasEngineType());
}

/**
 * Check if the vehicle needs to go to a depot in near future (if a opportunity presents itself) for service or replacement.
 *
 * @see NeedsAutomaticServicing()
 * @return true if the vehicle should go to a depot if a opportunity presents itself.
 */
bool Vehicle::NeedsServicing() const
{
        /* Stopped or crashed vehicles will not move, as such making unmovable
         * vehicles to go for service is lame. */
        if (this->vehstatus & (VS_STOPPED | VS_CRASHED)) return false;

        /* Are we ready for the next service cycle? */
        const Company *c = Company::Get(this->owner);
        if (this->ServiceIntervalIsPercent() ?
                        (this->reliability >= this->GetEngine()->reliability * (100 - this->GetServiceInterval()) / 100) :
                        (this->date_of_last_service + this->GetServiceInterval() >= _date)) {
                return false;
        }

        /* If we're servicing anyway, because we have not disabled servicing when
         * there are no breakdowns or we are playing with breakdowns, bail out. */
        if (!_settings_game.order.no_servicing_if_no_breakdowns ||
                        _settings_game.difficulty.vehicle_breakdowns != 0) {
                return true;
        }

        /* Test whether there is some pending autoreplace.
         * Note: We do this after the service-interval test.
         * There are a lot more reasons for autoreplace to fail than we can test here reasonably. */
        bool pending_replace = false;
        Money needed_money = c->settings.engine_renew_money;
        if (needed_money > c->money) return false;

        for (const Vehicle *v = this; v != NULL; v = (v->type == VEH_TRAIN) ? Train::From(v)->GetNextUnit() : NULL) {
                bool replace_when_old = false;
                EngineID new_engine = EngineReplacementForCompany(c, v->engine_type, v->group_id, &replace_when_old);

                /* Check engine availability */
                if (new_engine == INVALID_ENGINE || !HasBit(Engine::Get(new_engine)->company_avail, v->owner)) continue;
                /* Is the vehicle old if we are not always replacing? */
                if (replace_when_old && !v->NeedsAutorenewing(c, false)) continue;

                /* Check refittability */
                uint32 available_cargo_types, union_mask;
                GetArticulatedRefitMasks(new_engine, true, &union_mask, &available_cargo_types);
                /* Is there anything to refit? */
                if (union_mask != 0) {
                        CargoID cargo_type;
                        /* We cannot refit to mixed cargoes in an automated way */
                        if (IsArticulatedVehicleCarryingDifferentCargoes(v, &cargo_type)) continue;

                        /* Did the old vehicle carry anything? */
                        if (cargo_type != CT_INVALID) {
                                /* We can't refit the vehicle to carry the cargo we want */
                                if (!HasBit(available_cargo_types, cargo_type)) continue;
                        }
                }

                /* Check money.
                 * We want 2*(the price of the new vehicle) without looking at the value of the vehicle we are going to sell. */
                pending_replace = true;
                needed_money += 2 * Engine::Get(new_engine)->GetCost();
                if (needed_money > c->money) return false;
        }

        return pending_replace;
}

/**
 * Checks if the current order should be interrupted for a service-in-depot order.
 * @see NeedsServicing()
 * @return true if the current order should be interrupted.
 */
bool Vehicle::NeedsAutomaticServicing() const
{
        if (this->HasDepotOrder()) return false;
        if (this->current_order.IsType(OT_LOADING)) return false;
        if (this->current_order.IsType(OT_GOTO_DEPOT) && this->current_order.GetDepotOrderType() != ODTFB_SERVICE) return false;
        return NeedsServicing();
}

uint Vehicle::Crash(bool flooded)
{
        assert((this->vehstatus & VS_CRASHED) == 0);
        assert(this->Previous() == NULL); // IsPrimaryVehicle fails for free-wagon-chains

        uint pass = 0;
        /* Stop the vehicle. */
        if (this->IsPrimaryVehicle()) this->vehstatus |= VS_STOPPED;
        /* crash all wagons, and count passengers */
        for (Vehicle *v = this; v != NULL; v = v->Next()) {
                /* We do not transfer reserver cargo back, so TotalCount() instead of StoredCount() */
                if (IsCargoInClass(v->cargo_type, CC_PASSENGERS)) pass += v->cargo.TotalCount();
                v->vehstatus |= VS_CRASHED;
                MarkSingleVehicleDirty(v);
        }

        /* Dirty some windows */
        InvalidateWindowClassesData(GetWindowClassForVehicleType(this->type), 0);
        SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
        SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
        SetWindowDirty(WC_VEHICLE_DEPOT, this->tile);

        delete this->cargo_payment;
        this->cargo_payment = NULL;

        return RandomRange(pass + 1); // Randomise deceased passengers.
}


/**
 * Displays a "NewGrf Bug" error message for a engine, and pauses the game if not networking.
 * @param engine The engine that caused the problem
 * @param part1  Part 1 of the error message, taking the grfname as parameter 1
 * @param part2  Part 2 of the error message, taking the engine as parameter 2
 * @param bug_type Flag to check and set in grfconfig
 * @param critical Shall the "OpenTTD might crash"-message be shown when the player tries to unpause?
 */
void ShowNewGrfVehicleError(EngineID engine, StringID part1, StringID part2, GRFBugs bug_type, bool critical)
{
        const Engine *e = Engine::Get(engine);
        GRFConfig *grfconfig = GetGRFConfig(e->GetGRFID());

        if (!HasBit(grfconfig->grf_bugs, bug_type)) {
                SetBit(grfconfig->grf_bugs, bug_type);
                SetDParamStr(0, grfconfig->GetName());
                SetDParam(1, engine);
                ShowErrorMessage(part1, part2, WL_CRITICAL);
                if (!_networking) DoCommand(0, critical ? PM_PAUSED_ERROR : PM_PAUSED_NORMAL, 1, DC_EXEC, CMD_PAUSE);
        }

        /* debug output */
        char buffer[512];

        SetDParamStr(0, grfconfig->GetName());
        GetString(buffer, part1, lastof(buffer));
        DEBUG(grf, 0, "%s", buffer + 3);

        SetDParam(1, engine);
        GetString(buffer, part2, lastof(buffer));
        DEBUG(grf, 0, "%s", buffer + 3);
}

/**
 * Logs a bug in GRF and shows a warning message if this
 * is for the first time this happened.
 * @param u first vehicle of chain
 */
void VehicleLengthChanged(const Vehicle *u)
{
        /* show a warning once for each engine in whole game and once for each GRF after each game load */
        const Engine *engine = u->GetEngine();
        uint32 grfid = engine->grf_prop.grffile->grfid;
        GRFConfig *grfconfig = GetGRFConfig(grfid);
        if (GamelogGRFBugReverse(grfid, engine->grf_prop.local_id) || !HasBit(grfconfig->grf_bugs, GBUG_VEH_LENGTH)) {
                ShowNewGrfVehicleError(u->engine_type, STR_NEWGRF_BROKEN, STR_NEWGRF_BROKEN_VEHICLE_LENGTH, GBUG_VEH_LENGTH, true);
        }
}

/**
 * Vehicle constructor.
 * @param type Type of the new vehicle.
 */
Vehicle::Vehicle(VehicleType type)
{
        this->type               = type;
        this->coord.left         = INVALID_COORD;
        this->group_id           = DEFAULT_GROUP;
        this->fill_percent_te_id = INVALID_TE_ID;
        this->first              = this;
        this->colourmap          = PAL_NONE;
        this->cargo_age_counter  = 1;
        this->last_station_visited = INVALID_STATION;
        this->last_loading_station = INVALID_STATION;
}

/**
 * Get a value for a vehicle's random_bits.
 * @return A random value from 0 to 255.
 */
byte VehicleRandomBits()
{
        return GB(Random(), 0, 8);
}


/**
 * Vehicle hash update template function
 * @param v The vehicle to update
 * @param link The vehicle link to update within Vehicle
 * @param old_hash The hash to remove the vehicle from, if any
 * @param new_hash The hash to add the vehicle to, if any
 */
static void UpdateVehicleHash(Vehicle *v, VehicleHashLink Vehicle::*link, Vehicle **old_hash, Vehicle **new_hash)
{
        if (old_hash == new_hash) return;

        /* Remove from the old position in the hash table */
        if (old_hash != NULL) {
                if ((v->*link).next != NULL) ((v->*link).next->*link).pprev = (v->*link).pprev;
                *(v->*link).pprev = (v->*link).next;
        }

        /* Insert vehicle at beginning of the new position in the hash table */
        if (new_hash != NULL) {
                (v->*link).next = *new_hash;
                if ((v->*link).next != NULL) ((v->*link).next->*link).pprev = &(v->*link).next;
                (v->*link).pprev = new_hash;
                *new_hash = v;
        }
}

/* Forward declaration for HashAreaIterator */
template <uint nx, uint ny>
struct HashAreaIterator;

/**
 * Hash pack template class
 * @tparam nx Number of bits to use for x.
 * @tparam ny Number of bits to use for y.
 */
template <uint nx, uint ny>
struct HashPack {
        static const uint PACK_BIT0_X = 0;
        static const uint PACK_BITS_X = nx;
        static const uint PACK_MASK_X = ((1 << PACK_BITS_X) - 1) << PACK_BIT0_X;

        static const uint PACK_BIT0_Y = PACK_BIT0_X + PACK_BITS_X;
        static const uint PACK_BITS_Y = ny;
        static const uint PACK_MASK_Y = ((1 << PACK_BITS_Y) - 1) << PACK_BIT0_Y;

        static const uint PACK_BITS = PACK_BIT0_Y + PACK_BITS_Y;
        static const uint PACK_SIZE = 1 << PACK_BITS;

        typedef HashAreaIterator <nx, ny> AreaIterator;

        static inline uint pack_x (uint x)
        {
                return (x << PACK_BIT0_X) & PACK_MASK_X;
        }

        static inline uint pack_y (uint y)
        {
                return (y << PACK_BIT0_Y) & PACK_MASK_Y;
        }

        static inline uint pack (uint x, uint y)
        {
                return pack_x(x) + pack_y(y);
        }

        static inline uint next_x (uint x)
        {
                return (x + (1 << PACK_BIT0_X)) & PACK_MASK_X;
        }

        static inline uint next_y (uint y)
        {
                return (y + (1 << PACK_BIT0_Y)) & PACK_MASK_Y;
        }
};

/**
 * Area iterator for a hash class
 * @tparam nx Number of bits to use for x.
 * @tparam ny Number of bits to use for y.
 */
template <uint nx, uint ny>
struct HashAreaIterator : HashPack <nx, ny> {
        uint x0, x1, y0, y1;
        uint x, y;

        void reset (uint xx0, uint xx1, uint yy0, uint yy1)
        {
                x0 = this->pack_x (xx0);
                x1 = this->pack_x (xx1);

                y0 = this->pack_y (yy0);
                y1 = this->pack_y (yy1);

                x = x0;
                y = y0;
        }

        uint get() const
        {
                return x + y;
        }

        bool next()
        {
                if (x != x1) {
                        x = this->next_x(x);
                        return true;
                } else if (y != y1) {
                        y = this->next_y(y);
                        x = x0;
                        return true;
                } else {
                        return false;
                }
        }
};


struct VehicleTileHash : HashPack <7, 7> {
        /* Size of the hash, 6 = 64 x 64, 7 = 128 x 128. Larger sizes will (in theory) reduce hash
         * lookup times at the expense of memory usage. */

        /* Resolution of the hash, 0 = 1*1 tile, 1 = 2*2 tiles, 2 = 4*4 tiles, etc.
         * Profiling results show that 0 is fastest. */
        static const uint HASH_RES = 0;

        static const uint HASH_OFFSET_X = HASH_RES;
        static const uint HASH_BITS_X   = PACK_BITS_X;

        static const uint HASH_OFFSET_Y = HASH_RES;
        static const uint HASH_BITS_Y   = PACK_BITS_Y;

        static const uint HASH_SIZE = PACK_SIZE;

        Vehicle *buckets[HASH_SIZE];

        static inline uint hash (int x, int y)
        {
                return pack (GB(x, HASH_OFFSET_X, HASH_BITS_X), GB(y, HASH_OFFSET_Y, HASH_BITS_Y));
        }

        static inline uint hash (TileIndex tile)
        {
                return hash (TileX(tile), TileY(tile));
        }

        inline Vehicle **get_bucket (TileIndex tile)
        {
                return &this->buckets[hash(tile)];
        }

        void update (Vehicle *v, bool remove = false)
        {
                Vehicle **new_hash = remove ? NULL : get_bucket(v->tile);

                UpdateVehicleHash(v, &Vehicle::hash_tile_link,
                        v->hash_tile_current, new_hash);

                /* Remember current hash position */
                v->hash_tile_current = new_hash;
        }

        void reset()
        {
                Vehicle *v;
                FOR_ALL_VEHICLES(v) { v->hash_tile_current = NULL; }
                memset (this->buckets, 0, sizeof(this->buckets));
        }

        void setup_iter (AreaIterator *iter, int xl, int xu, int yl, int yu)
        {
                iter->reset (GB(xl, HASH_OFFSET_X, HASH_BITS_X), GB(xu, HASH_OFFSET_X, HASH_BITS_X),
                             GB(yl, HASH_OFFSET_Y, HASH_BITS_Y), GB(yu, HASH_OFFSET_Y, HASH_BITS_Y));
        }
};

static VehicleTileHash vehicle_tile_hash;

/**
 * Get the first vehicle for a VehicleTileIterator
 * @param tile The tile to iterate at
 */
Vehicle *VehicleTileIterator::first (TileIndex tile)
{
        return *vehicle_tile_hash.get_bucket(tile);
}


/**
 * Helper function for FindVehicleOnPos/HasVehicleOnPos.
 * @note Do not call this function directly!
 * @param x    The X location on the map
 * @param y    The Y location on the map
 * @param data Arbitrary data passed to proc
 * @param proc The proc that determines whether a vehicle will be "found".
 * @param find_first Whether to return on the first found or iterate over
 *                   all vehicles
 * @return the best matching or first vehicle (depending on find_first).
 */
static Vehicle *VehicleFromPosXY(int x, int y, void *data, VehicleFromPosProc *proc, bool find_first)
{
        const int COLL_DIST = 6;

        /* Hash area to scan is from xl,yl to xu,yu */
        VehicleTileHash::AreaIterator iter;
        vehicle_tile_hash.setup_iter (&iter,
                (x - COLL_DIST) / TILE_SIZE, (x + COLL_DIST) / TILE_SIZE,
                (y - COLL_DIST) / TILE_SIZE, (y + COLL_DIST) / TILE_SIZE);

        do {
                Vehicle *v = vehicle_tile_hash.buckets[iter.get()];
                for (; v != NULL; v = v->hash_tile_link.next) {
                        Vehicle *a = proc(v, data);
                        if (find_first && a != NULL) return a;
                }
        } while (iter.next());

        return NULL;
}

/**
 * Find a vehicle from a specific location. It will call proc for ALL vehicles
 * on the tile and YOU must make SURE that the "best one" is stored in the
 * data value and is ALWAYS the same regardless of the order of the vehicles
 * where proc was called on!
 * When you fail to do this properly you create an almost untraceable DESYNC!
 * @note The return value of proc will be ignored.
 * @note Use this when you have the intention that all vehicles
 *       should be iterated over.
 * @param x    The X location on the map
 * @param y    The Y location on the map
 * @param data Arbitrary data passed to proc
 * @param proc The proc that determines whether a vehicle will be "found".
 */
void FindVehicleOnPosXY(int x, int y, void *data, VehicleFromPosProc *proc)
{
        VehicleFromPosXY(x, y, data, proc, false);
}

/**
 * Checks whether a vehicle in on a specific location. It will call proc for
 * vehicles until it returns non-NULL.
 * @note Use FindVehicleOnPosXY when you have the intention that all vehicles
 *       should be iterated over.
 * @param x    The X location on the map
 * @param y    The Y location on the map
 * @param data Arbitrary data passed to proc
 * @param proc The proc that determines whether a vehicle will be "found".
 * @return True if proc returned non-NULL.
 */
bool HasVehicleOnPosXY(int x, int y, void *data, VehicleFromPosProc *proc)
{
        return VehicleFromPosXY(x, y, data, proc, true) != NULL;
}

/**
 * Ensure there is no vehicle at the ground at the given position.
 * @param tile Position to examine.
 * @return Succeeded command (ground is free) or failed command (a vehicle is found).
 */
CommandCost EnsureNoVehicleOnGround(TileIndex tile)
{
        int z = GetTileMaxPixelZ(tile);

        VehicleTileFinder iter (tile);
        Vehicle *v = NULL;
        while (!iter.finished()) {
                v = iter.next();

                if (v->type == VEH_DISASTER || (v->type == VEH_AIRCRAFT && v->subtype == AIR_SHADOW)) continue;
                if (v->z_pos > z) continue;

                iter.set_found();
        }

        /* Value v is not safe in MP games, however, it is used to generate a local
         * error message only (which may be different for different machines).
         * Such a message does not affect MP synchronisation.
         */
        if (iter.was_found()) return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY + v->type);
        return CommandCost();
}

/**
 * Finds vehicle in tunnel / bridge
 * @param tile first end
 * @param endtile second end
 * @param ignore Ignore this vehicle when searching
 * @return Succeeded command (if tunnel/bridge is free) or failed command (if a vehicle is using the tunnel/bridge).
 */
CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle *ignore)
{
        /* Value v is not safe in MP games, however, it is used to generate a local
         * error message only (which may be different for different machines).
         * Such a message does not affect MP synchronisation.
         */
        Vehicle *v = NULL;

        VehicleTileFinder iter1 (tile);
        while (!iter1.finished()) {
                v = iter1.next();

                if (v->type != VEH_TRAIN && v->type != VEH_ROAD && v->type != VEH_SHIP) continue;
                if (v == ignore) continue;

                iter1.set_found();
        }
        if (iter1.was_found()) return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY + v->type);

        VehicleTileFinder iter2 (tile);
        while (!iter2.finished()) {
                v = iter2.next();

                if (v->type != VEH_TRAIN && v->type != VEH_ROAD && v->type != VEH_SHIP) continue;
                if (v == ignore) continue;

                iter2.set_found();
        }
        if (iter2.was_found()) return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY + v->type);

        return CommandCost();
}

static Track AllowedNonOverlappingTrack(TrackBits bits)
{
        switch (bits) {
                case TRACK_BIT_UPPER: return TRACK_LOWER;
                case TRACK_BIT_LOWER: return TRACK_UPPER;
                case TRACK_BIT_LEFT:  return TRACK_RIGHT;
                case TRACK_BIT_RIGHT: return TRACK_LEFT;
                default: return INVALID_TRACK;
        }
}

/**
 * Tests if a vehicle interacts with the specified track bits.
 * All track bits interact except parallel #TRACK_BIT_HORZ or #TRACK_BIT_VERT.
 *
 * @param tile The tile.
 * @param track_bits The track bits.
 * @return \c true if no train that interacts, is found. \c false if a train is found.
 */
CommandCost EnsureNoTrainOnTrackBits(TileIndex tile, TrackBits track_bits)
{
        assert(track_bits != TRACK_BIT_NONE);

        Track allowed = AllowedNonOverlappingTrack(track_bits);

        VehicleTileFinder iter (tile);
        while (!iter.finished()) {
                Vehicle *v = iter.next();
                if (v->type != VEH_TRAIN) continue;

                Trackdir trackdir = Train::From(v)->trackdir;
                if (trackdir >= TRACKDIR_END) continue; // in wormhole or depot

                if (TrackdirToTrack(trackdir) != allowed) iter.set_found();
        }

        if (iter.was_found()) return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY);
        return CommandCost();
}

static bool EnsureNoTrainOnBridgeEndTrackBits (TileIndex tile, TrackBits bits)
{
        assert(bits != TRACK_BIT_NONE);

        Track allowed = AllowedNonOverlappingTrack(bits);
        VehicleTileFinder iter (tile);
        while (!iter.finished()) {
                Vehicle *v = iter.next();
                if (v->type != VEH_TRAIN) continue;

                Trackdir trackdir = Train::From(v)->trackdir;
                if (TrackdirToTrack(trackdir) != allowed) iter.set_found();
        }

        return !iter.was_found();
}

/**
 * Tests if a train interacts with the specified track bits or is on the bridge middle part.
 *
 * @param tile1 one bridge end
 * @param bits1 track bits on first bridge end
 * @param tile2 the other bridge end
 * @param bits2 track bits on second bridge end
 * @return whether there is a train on the bridge tracks or middle part
 */
CommandCost EnsureNoTrainOnBridgeTrackBits(TileIndex tile1, TrackBits bits1, TileIndex tile2, TrackBits bits2)
{
        if (!EnsureNoTrainOnBridgeEndTrackBits (tile1, bits1) ||
                        !EnsureNoTrainOnBridgeEndTrackBits (tile2, bits2)) {
                return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY);
        }

        return CommandCost();
}

static bool EnsureNoTrainOnTunnelBridgeEndMiddle (TileIndex tile)
{
        VehicleTileFinder iter (tile);
        while (!iter.finished()) {
                Vehicle *v = iter.next();
                if (v->type == VEH_TRAIN && Train::From(v)->trackdir == TRACKDIR_WORMHOLE) iter.set_found();
        }
        return !iter.was_found();
}

/**
 * Tests if there is a train on the middle bridge part
 * @param tile1 one bridge end
 * @param tile2 the other bridge end
 * @return whether there is a train on the bridge
 */
CommandCost EnsureNoTrainOnTunnelBridgeMiddle(TileIndex tile1, TileIndex tile2)
{
        if (!EnsureNoTrainOnTunnelBridgeEndMiddle(tile1) ||
                        !EnsureNoTrainOnTunnelBridgeEndMiddle(tile2)) {
                return_cmd_error(STR_ERROR_TRAIN_IN_THE_WAY);
        }

        return CommandCost();
}


struct VehicleViewportHash : HashPack <6, 6> {
        static const uint HASH_OFFSET_X = 7 + ZOOM_LVL_SHIFT;
        static const uint HASH_BITS_X   = PACK_BITS_X;

        static const uint HASH_OFFSET_Y = 6 + ZOOM_LVL_SHIFT;
        static const uint HASH_BITS_Y   = PACK_BITS_Y;

        static const uint HASH_SIZE = PACK_SIZE;

        Vehicle *buckets[HASH_SIZE];

        static inline uint hash (int x, int y)
        {
                return pack (GB(x, HASH_OFFSET_X, HASH_BITS_X), GB(y, HASH_OFFSET_Y, HASH_BITS_Y));
        }

        inline Vehicle **get_bucket (int x, int y)
        {
                return (x == INVALID_COORD) ? NULL : &buckets[hash(x, y)];
        }

        void update (Vehicle *v, int x, int y)
        {
                UpdateVehicleHash(v, &Vehicle::hash_viewport_link,
                        this->get_bucket (v->coord.left, v->coord.top),
                        this->get_bucket (x, y));
        }

        void reset()
        {
                memset (this->buckets, 0, sizeof(this->buckets));
        }

        void setup_iter (AreaIterator *iter, int l, uint w, int t, uint h)
        {
                uint x0, x1, y0, y1;

                if (w < (1 << (HASH_OFFSET_X + HASH_BITS_X))) {
                        x0 = GB(l,     HASH_OFFSET_X, HASH_BITS_X);
                        x1 = GB(l + w, HASH_OFFSET_X, HASH_BITS_X);
                } else {
                        /* scan whole hash row */
                        x0 = 0;
                        x1 = (1 << HASH_BITS_X) - 1;
                }

                if (h < (1 << (HASH_OFFSET_Y + HASH_BITS_Y))) {
                        y0 = GB(t,     HASH_OFFSET_Y, HASH_BITS_Y);
                        y1 = GB(t + h, HASH_OFFSET_Y, HASH_BITS_Y);
                } else {
                        /* scan whole column */
                        y0 = 0;
                        y1 = (1 << HASH_BITS_Y) - 1;
                }

                iter->reset (x0, x1, y0, y1);

        }
};

static VehicleViewportHash vehicle_viewport_hash;

void ResetVehicleHash()
{
        vehicle_viewport_hash.reset();
        vehicle_tile_hash.reset();
}

void ResetVehicleColourMap()
{
        Vehicle *v;
        FOR_ALL_VEHICLES(v) { v->colourmap = PAL_NONE; }
}

/**
 * List of vehicles that should check for autoreplace this tick.
 * Mapping of vehicle -> leave depot immediately after autoreplace.
 */
typedef SmallMap<Vehicle *, bool, 4> AutoreplaceMap;
static AutoreplaceMap _vehicles_to_autoreplace;

void InitializeVehicles()
{
        _vehicles_to_autoreplace.Reset();
        ResetVehicleHash();
}

uint CountVehiclesInChain(const Vehicle *v)
{
        uint count = 0;
        do count++; while ((v = v->Next()) != NULL);
        return count;
}

/**
 * Check if a vehicle is counted in num_engines in each company struct
 * @return true if the vehicle is counted in num_engines
 */
bool Vehicle::IsEngineCountable() const
{
        switch (this->type) {
                case VEH_AIRCRAFT: return Aircraft::From(this)->IsNormalAircraft(); // don't count plane shadows and helicopter rotors
                case VEH_TRAIN:
                        return !this->IsArticulatedPart() && // tenders and other articulated parts
                                        !Train::From(this)->IsRearDualheaded(); // rear parts of multiheaded engines
                case VEH_ROAD: return RoadVehicle::From(this)->IsFrontEngine();
                case VEH_SHIP: return true;
                default: return false; // Only count company buildable vehicles
        }
}

/**
 * Check whether Vehicle::engine_type has any meaning.
 * @return true if the vehicle has a useable engine type.
 */
bool Vehicle::HasEngineType() const
{
        switch (this->type) {
                case VEH_AIRCRAFT: return Aircraft::From(this)->IsNormalAircraft();
                case VEH_TRAIN:
                case VEH_ROAD:
                case VEH_SHIP: return true;
                default: return false;
        }
}

/**
 * Retrieves the engine of the vehicle.
 * @return Engine of the vehicle.
 * @pre HasEngineType() == true
 */
const Engine *Vehicle::GetEngine() const
{
        return Engine::Get(this->engine_type);
}

/**
 * Retrieve the NewGRF the vehicle is tied to.
 * This is the GRF providing the Action 3 for the engine type.
 * @return NewGRF associated to the vehicle.
 */
const GRFFile *Vehicle::GetGRF() const
{
        return this->GetEngine()->GetGRF();
}

/**
 * Retrieve the GRF ID of the NewGRF the vehicle is tied to.
 * This is the GRF providing the Action 3 for the engine type.
 * @return GRF ID of the associated NewGRF.
 */
uint32 Vehicle::GetGRFID() const
{
        return this->GetEngine()->GetGRFID();
}

/**
 * Handle the pathfinding result, especially the lost status.
 * If the vehicle is now lost and wasn't previously fire an
 * event to the AIs and a news message to the user. If the
 * vehicle is not lost anymore remove the news message.
 * @param path_found Whether the vehicle has a path to its destination.
 */
void Vehicle::HandlePathfindingResult(bool path_found)
{
        if (path_found) {
                /* Route found, is the vehicle marked with "lost" flag? */
                if (!HasBit(this->vehicle_flags, VF_PATHFINDER_LOST)) return;

                /* Clear the flag as the PF's problem was solved. */
                ClrBit(this->vehicle_flags, VF_PATHFINDER_LOST);
                /* Delete the news item. */
                DeleteVehicleNews(this->index, STR_NEWS_VEHICLE_IS_LOST);
                return;
        }

        /* Were we already lost? */
        if (HasBit(this->vehicle_flags, VF_PATHFINDER_LOST)) return;

        /* It is first time the problem occurred, set the "lost" flag. */
        SetBit(this->vehicle_flags, VF_PATHFINDER_LOST);
        /* Notify user about the event. */
        AI::NewEvent(this->owner, new ScriptEventVehicleLost(this->index));
        if (_settings_client.gui.lost_vehicle_warn && this->owner == _local_company) {
                SetDParam(0, this->index);
                AddVehicleAdviceNewsItem(STR_NEWS_VEHICLE_IS_LOST, this->index);
        }
}

/** Destroy all stuff that (still) needs the virtual functions to work properly */
void Vehicle::PreDestructor()
{
        if (CleaningPool()) return;

        if (Station::IsValidID(this->last_station_visited)) {
                Station *st = Station::Get(this->last_station_visited);
                st->loading_vehicles.remove(this);

                HideFillingPercent(&this->fill_percent_te_id);
                this->CancelReservation(INVALID_STATION, st);
                delete this->cargo_payment;
        }

        if (this->IsEngineCountable()) {
                GroupStatistics::CountEngine(this, -1);
                if (this->IsPrimaryVehicle()) GroupStatistics::CountVehicle(this, -1);
                GroupStatistics::UpdateAutoreplace(this->owner);

                if (this->owner == _local_company) InvalidateAutoreplaceWindow(this->engine_type, this->group_id);
                DeleteGroupHighlightOfVehicle(this);
        }

        if (this->type == VEH_AIRCRAFT && this->IsPrimaryVehicle()) {
                Aircraft *a = Aircraft::From(this);
                Station *st = GetTargetAirportIfValid(a);
                if (st != NULL) {
                        const AirportFTA *layout = st->airport.GetFTA()->layout;
                        CLRBITS(st->airport.flags, layout[a->previous_pos].block | layout[a->pos].block);
                }
        }


        if (this->type == VEH_ROAD && this->IsPrimaryVehicle()) {
                RoadVehicle *v = RoadVehicle::From(this);
                if (!(v->vehstatus & VS_CRASHED) && IsInsideMM(v->state, RVSB_IN_DT_ROAD_STOP, RVSB_IN_DT_ROAD_STOP_END)) {
                        /* Leave the drive through roadstop, when you have not already left it. */
                        RoadStop::GetByTile(v->tile, GetRoadStopType(v->tile))->Leave(v);
                }
        }

        if (this->Previous() == NULL) {
                InvalidateWindowData(WC_VEHICLE_DEPOT, this->tile);
        }

        if (this->IsPrimaryVehicle()) {
                DeleteWindowById(WC_VEHICLE_VIEW, this->index);
                DeleteWindowById(WC_VEHICLE_ORDERS, this->index);
                DeleteWindowById(WC_VEHICLE_REFIT, this->index);
                DeleteWindowById(WC_VEHICLE_DETAILS, this->index);
                DeleteWindowById(WC_VEHICLE_TIMETABLE, this->index);
                SetWindowDirty(WC_COMPANY, this->owner);
                OrderBackup::ClearVehicle(this);
        }
        InvalidateWindowClassesData(GetWindowClassForVehicleType(this->type), 0);

        this->cargo.Truncate();
        DeleteVehicleOrders(this);
        DeleteDepotHighlightOfVehicle(this);

        extern void StopGlobalFollowVehicle(const Vehicle *v);
        StopGlobalFollowVehicle(this);

        ReleaseDisastersTargetingVehicle(this->index);
}

Vehicle::~Vehicle()
{
        if (CleaningPool()) {
                this->cargo.OnCleanPool();
                return;
        }

        /* sometimes, eg. for disaster vehicles, when company bankrupts, when removing crashed/flooded vehicles,
         * it may happen that vehicle chain is deleted when visible */
        if (!(this->vehstatus & VS_HIDDEN)) MarkSingleVehicleDirty(this);

        Vehicle *v = this->Next();
        this->SetNext(NULL);

        delete v;

        vehicle_tile_hash.update (this, true);
        vehicle_viewport_hash.update (this, INVALID_COORD, 0);
        DeleteVehicleNews(this->index, INVALID_STRING_ID);
        DeleteNewGRFInspectWindow(GetGrfSpecFeature(this->type), this->index);
}

/**
 * Adds a vehicle to the list of vehicles that visited a depot this tick
 * @param *v vehicle to add
 */
void VehicleEnteredDepotThisTick(Vehicle *v)
{
        /* Vehicle should stop in the depot if it was in 'stopping' state */
        _vehicles_to_autoreplace[v] = !(v->vehstatus & VS_STOPPED);

        /* We ALWAYS set the stopped state. Even when the vehicle does not plan on
         * stopping in the depot, so we stop it to ensure that it will not reserve
         * the path out of the depot before we might autoreplace it to a different
         * engine. The new engine would not own the reserved path we store that we
         * stopped the vehicle, so autoreplace can start it again */
        v->vehstatus |= VS_STOPPED;
}

/**
 * Increases the day counter for all vehicles and calls 1-day and 32-day handlers.
 * Each tick, it processes vehicles with "index % DAY_TICKS == _date_fract",
 * so each day, all vehicles are processes in DAY_TICKS steps.
 */
static void RunVehicleDayProc()
{
        if (_game_mode != GM_NORMAL) return;

        /* Run the day_proc for every DAY_TICKS vehicle starting at _date_fract. */
        for (size_t i = _date_fract; i < Vehicle::GetPoolSize(); i += DAY_TICKS) {
                Vehicle *v = Vehicle::Get(i);
                if (v == NULL) continue;

                /* Call the 32-day callback if needed */
                if ((v->day_counter & 0x1F) == 0 && v->HasEngineType()) {
                        uint16 callback = GetVehicleCallback(CBID_VEHICLE_32DAY_CALLBACK, 0, 0, v->engine_type, v);
                        if (callback != CALLBACK_FAILED) {
                                if (HasBit(callback, 0)) {
                                        TriggerVehicle(v, VEHICLE_TRIGGER_CALLBACK_32); // Trigger vehicle trigger 10
                                }

                                /* After a vehicle trigger, the graphics and properties of the vehicle could change.
                                 * Note: MarkDirty also invalidates the palette, which is the meaning of bit 1. So, nothing special there. */
                                if (callback != 0) v->First()->MarkDirty();

                                if (callback & ~3) ErrorUnknownCallbackResult(v->GetGRFID(), CBID_VEHICLE_32DAY_CALLBACK, callback);
                        }
                }

                /* This is called once per day for each vehicle, but not in the first tick of the day */
                v->OnNewDay();
        }
}

void CallVehicleTicks()
{
        _vehicles_to_autoreplace.Clear();

        RunVehicleDayProc();

        Station *st;
        FOR_ALL_STATIONS(st) LoadUnloadStation(st);

        Vehicle *v;
        FOR_ALL_VEHICLES(v) {
                /* Vehicle could be deleted in this tick */
                if (!v->Tick()) {
                        assert(Vehicle::Get(vehicle_index) == NULL);
                        continue;
                }

                assert(Vehicle::Get(vehicle_index) == v);

                switch (v->type) {
                        default: break;

                        case VEH_TRAIN:
                        case VEH_ROAD:
                        case VEH_AIRCRAFT:
                        case VEH_SHIP: {
                                Vehicle *front = v->First();

                                if (v->vcache.cached_cargo_age_period != 0) {
                                        v->cargo_age_counter = min(v->cargo_age_counter, v->vcache.cached_cargo_age_period);
                                        if (--v->cargo_age_counter == 0) {
                                                v->cargo.AgeCargo();
                                                v->cargo_age_counter = v->vcache.cached_cargo_age_period;
                                        }
                                }

                                /* Do not play any sound when crashed */
                                if (front->vehstatus & VS_CRASHED) continue;

                                /* Do not play any sound when in depot or tunnel */
                                if (v->vehstatus & VS_HIDDEN) continue;

                                /* Do not play any sound when stopped */
                                if ((front->vehstatus & VS_STOPPED) && (front->type != VEH_TRAIN || front->cur_speed == 0)) continue;

                                /* Check vehicle type specifics */
                                switch (v->type) {
                                        case VEH_TRAIN:
                                                if (Train::From(v)->IsWagon()) continue;
                                                break;

                                        case VEH_ROAD:
                                                if (!RoadVehicle::From(v)->IsFrontEngine()) continue;
                                                break;

                                        case VEH_AIRCRAFT:
                                                if (!Aircraft::From(v)->IsNormalAircraft()) continue;
                                                break;

                                        default:
                                                break;
                                }

                                v->motion_counter += front->cur_speed;
                                /* Play a running sound if the motion counter passes 256 (Do we not skip sounds?) */
                                if (GB(v->motion_counter, 0, 8) < front->cur_speed) PlayVehicleSound(v, VSE_RUNNING);

                                /* Play an alternating running sound every 16 ticks */
                                if (GB(v->tick_counter, 0, 4) == 0) {
                                        /* Play running sound when speed > 0 and not braking */
                                        bool running = (front->cur_speed > 0) && !(front->vehstatus & (VS_STOPPED | VS_TRAIN_SLOWING));
                                        PlayVehicleSound(v, running ? VSE_RUNNING_16 : VSE_STOPPED_16);
                                }

                                break;
                        }
                }
        }

        Backup<CompanyByte> cur_company(_current_company, FILE_LINE);
        for (AutoreplaceMap::iterator it = _vehicles_to_autoreplace.Begin(); it != _vehicles_to_autoreplace.End(); it++) {
                v = it->first;
                /* Autoreplace needs the current company set as the vehicle owner */
                cur_company.Change(v->owner);

                /* Start vehicle if we stopped them in VehicleEnteredDepotThisTick()
                 * We need to stop them between VehicleEnteredDepotThisTick() and here or we risk that
                 * they are already leaving the depot again before being replaced. */
                if (it->second) v->vehstatus &= ~VS_STOPPED;

                /* Store the position of the effect as the vehicle pointer will become invalid later */
                int x = v->x_pos;
                int y = v->y_pos;
                int z = v->z_pos;

                const Company *c = Company::Get(_current_company);
                SubtractMoneyFromCompany(CommandCost(EXPENSES_NEW_VEHICLES, (Money)c->settings.engine_renew_money));
                CommandCost res = DoCommand(0, v->index, 0, DC_EXEC, CMD_AUTOREPLACE_VEHICLE);
                SubtractMoneyFromCompany(CommandCost(EXPENSES_NEW_VEHICLES, -(Money)c->settings.engine_renew_money));

                if (!IsLocalCompany()) continue;

                if (res.Succeeded()) {
                        ShowCostOrIncomeAnimation(x, y, z, res.GetCost());
                        continue;
                }

                StringID error_message = res.GetErrorMessage();
                if (error_message == STR_ERROR_AUTOREPLACE_NOTHING_TO_DO || error_message == INVALID_STRING_ID) continue;

                if (error_message == STR_ERROR_NOT_ENOUGH_CASH_REQUIRES_CURRENCY) error_message = STR_ERROR_AUTOREPLACE_MONEY_LIMIT;

                StringID message;
                if (error_message == STR_ERROR_TRAIN_TOO_LONG_AFTER_REPLACEMENT) {
                        message = error_message;
                } else {
                        message = STR_NEWS_VEHICLE_AUTORENEW_FAILED;
                }

                SetDParam(0, v->index);
                SetDParam(1, error_message);
                AddVehicleAdviceNewsItem(message, v->index);
        }

        cur_company.Restore();
}

/**
 * Add vehicle sprite for drawing to the screen.
 * @param v Vehicle to draw.
 */
static void DoDrawVehicle(const Vehicle *v)
{
        SpriteID image = v->cur_image;
        PaletteID pal = PAL_NONE;

        if (v->vehstatus & VS_DEFPAL) pal = (v->vehstatus & VS_CRASHED) ? PALETTE_CRASH : GetVehiclePalette(v);

        /* Check whether the vehicle shall be transparent due to the game state */
        bool shadowed = (v->vehstatus & VS_SHADOW) != 0;

        if (v->type == VEH_EFFECT) {
                /* Check whether the vehicle shall be transparent/invisible due to GUI settings.
                 * However, transparent smoke and bubbles look weird, so always hide them. */
                TransparencyOption to = EffectVehicle::From(v)->GetTransparencyOption();
                if (to != TO_INVALID && (IsTransparencySet(to) || IsInvisibilitySet(to))) return;
        }

        AddSortableSpriteToDraw(image, pal, v->x_pos + v->x_offs, v->y_pos + v->y_offs,
                v->x_extent, v->y_extent, v->z_extent, v->z_pos, shadowed, v->x_bb_offs, v->y_bb_offs);
}

/**
 * Add the vehicle sprites that should be drawn at a part of the screen.
 * @param dpi Rectangle being drawn.
 */
void ViewportAddVehicles(const DrawPixelInfo *dpi)
{
        /* The bounding rectangle */
        const int l = dpi->left;
        const int r = dpi->left + dpi->width;
        const int t = dpi->top;
        const int b = dpi->top + dpi->height;

        /* The hash area to scan */
        VehicleViewportHash::AreaIterator iter;
        vehicle_viewport_hash.setup_iter (&iter,
                l - (70 * ZOOM_LVL_BASE), dpi->width  + (70 * ZOOM_LVL_BASE),
                t - (70 * ZOOM_LVL_BASE), dpi->height + (70 * ZOOM_LVL_BASE));

        do {
                const Vehicle *v = vehicle_viewport_hash.buckets[iter.get()];

                while (v != NULL) {
                        if (!(v->vehstatus & VS_HIDDEN) &&
                                        l <= v->coord.right &&
                                        t <= v->coord.bottom &&
                                        r >= v->coord.left &&
                                        b >= v->coord.top) {
                                DoDrawVehicle(v);
                        }
                        v = v->hash_viewport_link.next;
                }

        } while (iter.next());
}

/**
 * Find the vehicle close to the clicked coordinates.
 * @param vp Viewport clicked in.
 * @param x  X coordinate in the viewport.
 * @param y  Y coordinate in the viewport.
 * @return Closest vehicle, or \c NULL if none found.
 */
Vehicle *CheckClickOnVehicle(const ViewPort *vp, int x, int y)
{
        Vehicle *found = NULL, *v;
        uint dist, best_dist = UINT_MAX;

        if ((uint)(x -= vp->left) >= (uint)vp->width || (uint)(y -= vp->top) >= (uint)vp->height) return NULL;

        x = ScaleByZoom(x, vp->zoom) + vp->virtual_left;
        y = ScaleByZoom(y, vp->zoom) + vp->virtual_top;

        FOR_ALL_VEHICLES(v) {
                if ((v->vehstatus & (VS_HIDDEN | VS_UNCLICKABLE)) == 0 &&
                                x >= v->coord.left && x <= v->coord.right &&
                                y >= v->coord.top && y <= v->coord.bottom) {

                        dist = max(
                                abs(((v->coord.left + v->coord.right) >> 1) - x),
                                abs(((v->coord.top + v->coord.bottom) >> 1) - y)
                        );

                        if (dist < best_dist) {
                                found = v;
                                best_dist = dist;
                        }
                }
        }

        return found;
}

/**
 * Decrease the value of a vehicle.
 * @param v %Vehicle to devaluate.
 */
void DecreaseVehicleValue(Vehicle *v)
{
        v->value -= v->value >> 8;
        SetWindowDirty(WC_VEHICLE_DETAILS, v->index);
}

static const byte _breakdown_chance[64] = {
          3,   3,   3,   3,   3,   3,   3,   3,
          4,   4,   5,   5,   6,   6,   7,   7,
          8,   8,   9,   9,  10,  10,  11,  11,
         12,  13,  13,  13,  13,  14,  15,  16,
         17,  19,  21,  25,  28,  31,  34,  37,
         40,  44,  48,  52,  56,  60,  64,  68,
         72,  80,  90, 100, 110, 120, 130, 140,
        150, 170, 190, 210, 230, 250, 250, 250,
};

void CheckVehicleBreakdown(Vehicle *v)
{
        int rel, rel_old;

        /* decrease reliability */
        v->reliability = rel = max((rel_old = v->reliability) - v->reliability_spd_dec, 0);
        if ((rel_old >> 8) != (rel >> 8)) SetWindowDirty(WC_VEHICLE_DETAILS, v->index);

        if (v->breakdown_ctr != 0 || (v->vehstatus & VS_STOPPED) ||
                        _settings_game.difficulty.vehicle_breakdowns < 1 ||
                        v->cur_speed < 5 || _game_mode == GM_MENU) {
                return;
        }

        uint32 r = Random();

        /* increase chance of failure */
        int chance = v->breakdown_chance + 1;
        if (Chance16I(1, 25, r)) chance += 25;
        v->breakdown_chance = min(255, chance);

        /* calculate reliability value to use in comparison */
        rel = v->reliability;
        if (v->type == VEH_SHIP) rel += 0x6666;

        /* reduced breakdowns? */
        if (_settings_game.difficulty.vehicle_breakdowns == 1) rel += 0x6666;

        /* check if to break down */
        if (_breakdown_chance[(uint)min(rel, 0xffff) >> 10] <= v->breakdown_chance) {
                v->breakdown_ctr    = GB(r, 16, 6) + 0x3F;
                v->breakdown_delay  = GB(r, 24, 7) + 0x80;
                v->breakdown_chance = 0;
        }
}

/**
 * Handle all of the aspects of a vehicle breakdown
 * This includes adding smoke and sounds, and ending the breakdown when appropriate.
 * @return true iff the vehicle is stopped because of a breakdown
 * @note This function always returns false for aircraft, since these never stop for breakdowns
 */
bool Vehicle::HandleBreakdown()
{
        /* Possible states for Vehicle::breakdown_ctr
         * 0  - vehicle is running normally
         * 1  - vehicle is currently broken down
         * 2  - vehicle is going to break down now
         * >2 - vehicle is counting down to the actual breakdown event */
        switch (this->breakdown_ctr) {
                case 0:
                        return false;

                case 2:
                        this->breakdown_ctr = 1;

                        if (this->breakdowns_since_last_service != 255) {
                                this->breakdowns_since_last_service++;
                        }

                        if (this->type == VEH_AIRCRAFT) {
                                /* Aircraft just need this flag, the rest is handled elsewhere */
                                this->vehstatus |= VS_AIRCRAFT_BROKEN;
                        } else {
                                this->cur_speed = 0;

                                if (!PlayVehicleSound(this, VSE_BREAKDOWN)) {
                                        SndPlayVehicleFx((_settings_game.game_creation.landscape != LT_TOYLAND) ?
                                                (this->type == VEH_TRAIN ? SND_10_TRAIN_BREAKDOWN : SND_0F_VEHICLE_BREAKDOWN) :
                                                (this->type == VEH_TRAIN ? SND_3A_COMEDY_BREAKDOWN_2 : SND_35_COMEDY_BREAKDOWN), this);
                                }

                                if (!(this->vehstatus & VS_HIDDEN) && !HasBit(EngInfo(this->engine_type)->misc_flags, EF_NO_BREAKDOWN_SMOKE)) {
                                        EffectVehicle *u = CreateEffectVehicleRel(this, 4, 4, 5, EV_BREAKDOWN_SMOKE);
                                        if (u != NULL) u->animation_state = this->breakdown_delay * 2;
                                }
                        }

                        this->MarkDirty(); // Update graphics after speed is zeroed
                        SetWindowDirty(WC_VEHICLE_VIEW, this->index);
                        SetWindowDirty(WC_VEHICLE_DETAILS, this->index);

                        /* FALL THROUGH */
                case 1:
                        /* Aircraft breakdowns end only when arriving at the airport */
                        if (this->type == VEH_AIRCRAFT) return false;

                        /* For trains this function is called twice per tick, so decrease v->breakdown_delay at half the rate */
                        if ((this->tick_counter & (this->type == VEH_TRAIN ? 3 : 1)) == 0) {
                                if (--this->breakdown_delay == 0) {
                                        this->breakdown_ctr = 0;
                                        this->MarkDirty();
                                        SetWindowDirty(WC_VEHICLE_VIEW, this->index);
                                }
                        }
                        return true;

                default:
                        if (!this->current_order.IsType(OT_LOADING)) this->breakdown_ctr--;
                        return false;
        }
}

/**
 * Update age of a vehicle.
 * @param v Vehicle to update.
 */
void AgeVehicle(Vehicle *v)
{
        if (v->age < MAX_DAY) {
                v->age++;
                if (v->IsPrimaryVehicle() && v->age == VEHICLE_PROFIT_MIN_AGE + 1) GroupStatistics::VehicleReachedProfitAge(v);
        }

        if (!v->IsPrimaryVehicle() && (v->type != VEH_TRAIN || !Train::From(v)->IsEngine())) return;

        int age = v->age - v->max_age;
        if (age == DAYS_IN_LEAP_YEAR * 0 || age == DAYS_IN_LEAP_YEAR * 1 ||
                        age == DAYS_IN_LEAP_YEAR * 2 || age == DAYS_IN_LEAP_YEAR * 3 || age == DAYS_IN_LEAP_YEAR * 4) {
                v->reliability_spd_dec <<= 1;
        }

        SetWindowDirty(WC_VEHICLE_DETAILS, v->index);

        /* Don't warn about non-primary or not ours vehicles or vehicles that are crashed */
        if (v->Previous() != NULL || v->owner != _local_company || (v->vehstatus & VS_CRASHED) != 0) return;

        /* Don't warn if a renew is active */
        if (Company::Get(v->owner)->settings.engine_renew && v->GetEngine()->company_avail != 0) return;

        StringID str;
        if (age == -DAYS_IN_LEAP_YEAR) {
                str = STR_NEWS_VEHICLE_IS_GETTING_OLD;
        } else if (age == 0) {
                str = STR_NEWS_VEHICLE_IS_GETTING_VERY_OLD;
        } else if (age > 0 && (age % DAYS_IN_LEAP_YEAR) == 0) {
                str = STR_NEWS_VEHICLE_IS_GETTING_VERY_OLD_AND;
        } else {
                return;
        }

        SetDParam(0, v->index);
        AddVehicleAdviceNewsItem(str, v->index);
}

/**
 * Calculates how full a vehicle is.
 * @param front The front vehicle of the consist to check.
 * @param colour The string to show depending on if we are unloading or loading
 * @return A percentage of how full the Vehicle is.
 */
uint8 CalcPercentVehicleFilled(const Vehicle *front, StringID *colour)
{
        int count = 0;
        int max = 0;
        int cars = 0;
        int unloading = 0;
        bool loading = false;

        bool is_loading = front->current_order.IsType(OT_LOADING);

        /* The station may be NULL when the (colour) string does not need to be set. */
        const Station *st = Station::GetIfValid(front->last_station_visited);
        assert(colour == NULL || (st != NULL && is_loading));

        bool order_no_load = is_loading && (front->current_order.GetLoadType() & OLFB_NO_LOAD);
        bool order_full_load = is_loading && (front->current_order.GetLoadType() & OLFB_FULL_LOAD);

        /* Count up max and used */
        for (const Vehicle *v = front; v != NULL; v = v->Next()) {
                count += v->cargo.StoredCount();
                max += v->cargo_cap;
                if (v->cargo_cap != 0 && colour != NULL) {
                        unloading += HasBit(v->vehicle_flags, VF_CARGO_UNLOADING) ? 1 : 0;
                        loading |= !order_no_load &&
                                        (order_full_load || st->goods[v->cargo_type].HasRating()) &&
                                        !HasBit(v->vehicle_flags, VF_LOADING_FINISHED) && !HasBit(v->vehicle_flags, VF_STOP_LOADING);
                        cars++;
                }
        }

        if (colour != NULL) {
                if (unloading == 0 && loading) {
                        *colour = STR_PERCENT_UP;
                } else if (unloading == 0 && !loading) {
                        *colour = STR_PERCENT_NONE;
                } else if (cars == unloading || !loading) {
                        *colour = STR_PERCENT_DOWN;
                } else {
                        *colour = STR_PERCENT_UP_DOWN;
                }
        }

        /* Train without capacity */
        if (max == 0) return 100;

        /* Return the percentage */
        return (count * 100) / max;
}

/**
 * Vehicle entirely entered the depot, update its status, orders, vehicle windows, service it, etc.
 * @param v Vehicle that entered a depot.
 */
void VehicleEnterDepot(Vehicle *v)
{
        /* Always work with the front of the vehicle */
        assert(v == v->First());

        switch (v->type) {
                case VEH_TRAIN: {
                        Train *t = Train::From(v);
                        SetWindowClassesDirty(WC_TRAINS_LIST);
                        /* Clear path reservation */
                        SetDepotReservation(t->tile, false);
                        if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(t->tile);

                        assert(IsSignalBufferEmpty());
                        AddDepotToSignalBuffer(t->tile, t->owner);
                        UpdateSignalsInBuffer();
                        t->wait_counter = 0;
                        t->force_proceed = TFP_NONE;
                        ClrBit(t->flags, VRF_TOGGLE_REVERSE);
                        t->ConsistChanged(true);
                        break;
                }

                case VEH_ROAD:
                        SetWindowClassesDirty(WC_ROADVEH_LIST);
                        break;

                case VEH_SHIP: {
                        SetWindowClassesDirty(WC_SHIPS_LIST);
                        Ship *ship = Ship::From(v);
                        ship->trackdir = TRACKDIR_DEPOT;
                        ship->UpdateCache();
                        ship->UpdateViewport(true, true);
                        SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);
                        break;
                }

                case VEH_AIRCRAFT:
                        SetWindowClassesDirty(WC_AIRCRAFT_LIST);
                        HandleAircraftEnterHangar(Aircraft::From(v));
                        break;
                default: NOT_REACHED();
        }
        SetWindowDirty(WC_VEHICLE_VIEW, v->index);

        if (v->type != VEH_TRAIN) {
                /* Trains update the vehicle list when the first unit enters the depot and calls VehicleEnterDepot() when the last unit enters.
                 * We only increase the number of vehicles when the first one enters, so we will not need to search for more vehicles in the depot */
                InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
        }
        SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);

        v->vehstatus |= VS_HIDDEN;
        v->cur_speed = 0;

        VehicleServiceInDepot(v);

        /* After a vehicle trigger, the graphics and properties of the vehicle could change. */
        TriggerVehicle(v, VEHICLE_TRIGGER_DEPOT);
        v->MarkDirty();

        if (v->current_order.IsType(OT_GOTO_DEPOT)) {
                SetWindowDirty(WC_VEHICLE_VIEW, v->index);

                const Order *real_order = v->GetOrder(v->cur_real_order_index);
                Order t = v->current_order;
                v->current_order.MakeDummy();

                /* Test whether we are heading for this depot. If not, do nothing.
                 * Note: The target depot for nearest-/manual-depot-orders is only updated on junctions, but we want to accept every depot. */
                if ((t.GetDepotOrderType() & ODTFB_PART_OF_ORDERS) &&
                                real_order != NULL && !(real_order->GetDepotActionType() & ODATFB_NEAREST_DEPOT) &&
                                (v->type == VEH_AIRCRAFT ? t.GetDestination() != GetStationIndex(v->tile) : v->dest_tile != v->tile)) {
                        /* We are heading for another depot, keep driving. */
                        return;
                }

                if (t.IsRefit()) {
                        Backup<CompanyByte> cur_company(_current_company, v->owner, FILE_LINE);
                        CommandCost cost = DoCommand(v->tile, v->index, t.GetRefitCargo() | 0xFF << 8, DC_EXEC, GetCmdRefitVeh(v));
                        cur_company.Restore();

                        if (cost.Failed()) {
                                _vehicles_to_autoreplace[v] = false;
                                if (v->owner == _local_company) {
                                        /* Notify the user that we stopped the vehicle */
                                        SetDParam(0, v->index);
                                        AddVehicleAdviceNewsItem(STR_NEWS_ORDER_REFIT_FAILED, v->index);
                                }
                        } else if (cost.GetCost() != 0) {
                                v->profit_this_year -= cost.GetCost() << 8;
                                if (v->owner == _local_company) {
                                        ShowCostOrIncomeAnimation(v->x_pos, v->y_pos, v->z_pos, cost.GetCost());
                                }
                        }
                }

                if (t.GetDepotOrderType() & ODTFB_PART_OF_ORDERS) {
                        /* Part of orders */
                        v->DeleteUnreachedImplicitOrders();
                        UpdateVehicleTimetable(v, true);
                        v->IncrementImplicitOrderIndex();
                }
                if (t.GetDepotActionType() & ODATFB_HALT) {
                        /* Vehicles are always stopped on entering depots. Do not restart this one. */
                        _vehicles_to_autoreplace[v] = false;
                        /* Invalidate last_loading_station. As the link from the station
                         * before the stop to the station after the stop can't be predicted
                         * we shouldn't construct it when the vehicle visits the next stop. */
                        v->last_loading_station = INVALID_STATION;
                        if (v->owner == _local_company) {
                                SetDParam(0, v->index);
                                AddVehicleAdviceNewsItem(STR_NEWS_TRAIN_IS_WAITING + v->type, v->index);
                        }
                        AI::NewEvent(v->owner, new ScriptEventVehicleWaitingInDepot(v->index));
                }
        }
}


/**
 * Update the position of the vehicle. This will update the hash that tells
 *  which vehicles are on a tile.
 * @param v The vehicle to update.
 */
void VehicleUpdatePosition(Vehicle *v)
{
        vehicle_tile_hash.update(v);
}

/**
 * Update the vehicle on the viewport, updating the right hash and setting the
 *  new coordinates.
 * @param v The vehicle to update.
 * @param dirty Mark the (new and old) coordinates of the vehicle as dirty.
 */
void VehicleUpdateViewport(Vehicle *v, bool dirty)
{
        int img = v->cur_image;
        Point pt = RemapCoords(v->x_pos + v->x_offs, v->y_pos + v->y_offs, v->z_pos);
        const Sprite *spr = GetSprite(img, ST_NORMAL);

        pt.x += spr->x_offs;
        pt.y += spr->y_offs;

        vehicle_viewport_hash.update (v, pt.x, pt.y);

        Rect old_coord = v->coord;
        v->coord.left   = pt.x;
        v->coord.top    = pt.y;
        v->coord.right  = pt.x + spr->width + 2 * ZOOM_LVL_BASE;
        v->coord.bottom = pt.y + spr->height + 2 * ZOOM_LVL_BASE;

        if (dirty) {
                if (old_coord.left == INVALID_COORD) {
                        MarkSingleVehicleDirty(v);
                } else {
                        MarkAllViewportsDirty(
                                min(old_coord.left,   v->coord.left),
                                min(old_coord.top,    v->coord.top),
                                max(old_coord.right,  v->coord.right) + 1 * ZOOM_LVL_BASE,
                                max(old_coord.bottom, v->coord.bottom) + 1 * ZOOM_LVL_BASE
                        );
                }
        }
}

/**
 * Update the position of the vehicle, and update the viewport.
 * @param v The vehicle to update.
 */
void VehicleUpdatePositionAndViewport(Vehicle *v)
{
        VehicleUpdatePosition(v);
        VehicleUpdateViewport(v, true);
}

/**
 * Marks viewports dirty where the vehicle's image is.
 * @param v vehicle to mark dirty
 */
void MarkSingleVehicleDirty(const Vehicle *v)
{
        MarkAllViewportsDirty(v->coord.left, v->coord.top, v->coord.right + 1 * ZOOM_LVL_BASE, v->coord.bottom + 1 * ZOOM_LVL_BASE);
}

/**
 * Get position information of a vehicle when moving one pixel in the direction it is facing
 * @param v Vehicle to move
 * @return Position information after the move
 */
VehiclePos GetNewVehiclePos(const Vehicle *v)
{
        static const int8 delta_coord[DIR_END][2] = { /* {x,y} */
                {-1,-1}, {-1,0}, {-1,1}, {0,1}, {1,1}, {1,0}, {1,-1}, {0,-1}
        };

        VehiclePos gp;
        gp.x = v->x_pos + delta_coord[v->direction][0];
        gp.y = v->y_pos + delta_coord[v->direction][1];
        gp.new_tile = TileVirtXY(gp.x, gp.y);
        return gp;
}

static const Direction _new_direction_table[] = {
        DIR_N,  DIR_NW, DIR_W,
        DIR_NE, DIR_SE, DIR_SW,
        DIR_E,  DIR_SE, DIR_S
};

Direction GetDirectionTowards(const Vehicle *v, int x, int y)
{
        int i = 0;

        if (y >= v->y_pos) {
                if (y != v->y_pos) i += 3;
                i += 3;
        }

        if (x >= v->x_pos) {
                if (x != v->x_pos) i++;
                i++;
        }

        Direction dir = v->direction;

        DirDiff dirdiff = DirDifference(_new_direction_table[i], dir);
        if (dirdiff == DIRDIFF_SAME) return dir;
        return ChangeDir(dir, dirdiff > DIRDIFF_REVERSE ? DIRDIFF_45LEFT : DIRDIFF_45RIGHT);
}

/**
 * Initializes the structure. Vehicle unit numbers are supposed not to change after
 * struct initialization, except after each call to this->NextID() the returned value
 * is assigned to a vehicle.
 * @param type type of vehicle
 * @param owner owner of vehicles
 */
FreeUnitIDGenerator::FreeUnitIDGenerator(VehicleType type, CompanyID owner) : cache(NULL), maxid(0), curid(0)
{
        /* Find maximum */
        const Vehicle *v;
        FOR_ALL_VEHICLES(v) {
                if (v->type == type && v->owner == owner) {
                        this->maxid = max<UnitID>(this->maxid, v->unitnumber);
                }
        }

        if (this->maxid == 0) return;

        /* Reserving 'maxid + 2' because we need:
         * - space for the last item (with v->unitnumber == maxid)
         * - one free slot working as loop terminator in FreeUnitIDGenerator::NextID() */
        this->cache = CallocT<bool>(this->maxid + 2);

        /* Fill the cache */
        FOR_ALL_VEHICLES(v) {
                if (v->type == type && v->owner == owner) {
                        this->cache[v->unitnumber] = true;
                }
        }
}

/** Returns next free UnitID. Supposes the last returned value was assigned to a vehicle. */
UnitID FreeUnitIDGenerator::NextID()
{
        if (this->maxid <= this->curid) return ++this->curid;

        while (this->cache[++this->curid]) { } // it will stop, we reserved more space than needed

        return this->curid;
}

/**
 * Get an unused unit number for a vehicle (if allowed).
 * @param type Type of vehicle
 * @return A unused unit number for the given type of vehicle if it is allowed to build one, else \c UINT16_MAX.
 */
UnitID GetFreeUnitNumber(VehicleType type)
{
        /* Check whether it is allowed to build another vehicle. */
        uint max_veh;
        switch (type) {
                case VEH_TRAIN:    max_veh = _settings_game.vehicle.max_trains;   break;
                case VEH_ROAD:     max_veh = _settings_game.vehicle.max_roadveh;  break;
                case VEH_SHIP:     max_veh = _settings_game.vehicle.max_ships;    break;
                case VEH_AIRCRAFT: max_veh = _settings_game.vehicle.max_aircraft; break;
                default: NOT_REACHED();
        }

        const Company *c = Company::Get(_current_company);
        if (c->group_all[type].num_vehicle >= max_veh) return UINT16_MAX; // Currently already at the limit, no room to make a new one.

        FreeUnitIDGenerator gen(type, _current_company);

        return gen.NextID();
}


/**
 * Check whether we can build infrastructure for the given
 * vehicle type. This to disable building stations etc. when
 * you are not allowed/able to have the vehicle type yet.
 * @param type the vehicle type to check this for
 * @return true if there is any reason why you may build
 *         the infrastructure for the given vehicle type
 */
bool CanBuildVehicleInfrastructure(VehicleType type)
{
        assert(IsCompanyBuildableVehicleType(type));

        if (!Company::IsValidID(_local_company)) return false;
        if (!_settings_client.gui.disable_unsuitable_building) return true;

        UnitID max;
        switch (type) {
                case VEH_TRAIN:    max = _settings_game.vehicle.max_trains; break;
                case VEH_ROAD:     max = _settings_game.vehicle.max_roadveh; break;
                case VEH_SHIP:     max = _settings_game.vehicle.max_ships; break;
                case VEH_AIRCRAFT: max = _settings_game.vehicle.max_aircraft; break;
                default: NOT_REACHED();
        }

        /* We can build vehicle infrastructure when we may build the vehicle type */
        if (max > 0) {
                /* Can we actually build the vehicle type? */
                const Engine *e;
                FOR_ALL_ENGINES_OF_TYPE(e, type) {
                        if (HasBit(e->company_avail, _local_company)) return true;
                }
                return false;
        }

        /* We should be able to build infrastructure when we have the actual vehicle type */
        const Vehicle *v;
        FOR_ALL_VEHICLES(v) {
                if (v->owner == _local_company && v->type == type) return true;
        }

        return false;
}


/**
 * Determines the #LiveryScheme for a vehicle.
 * @param engine_type Engine of the vehicle.
 * @param parent_engine_type Engine of the front vehicle, #INVALID_ENGINE if vehicle is at front itself.
 * @param v the vehicle, \c NULL if in purchase list etc.
 * @return livery scheme to use.
 */
LiveryScheme GetEngineLiveryScheme(EngineID engine_type, EngineID parent_engine_type, const Vehicle *v)
{
        CargoID cargo_type = v == NULL ? (CargoID)CT_INVALID : v->cargo_type;
        const Engine *e = Engine::Get(engine_type);
        switch (e->type) {
                default: NOT_REACHED();
                case VEH_TRAIN:
                        if (v != NULL && parent_engine_type != INVALID_ENGINE && (UsesWagonOverride(v) || (v->IsArticulatedPart() && e->u.rail.railveh_type != RAILVEH_WAGON))) {
                                /* Wagonoverrides use the colour scheme of the front engine.
                                 * Articulated parts use the colour scheme of the first part. (Not supported for articulated wagons) */
                                engine_type = parent_engine_type;
                                e = Engine::Get(engine_type);
                                /* Note: Luckily cargo_type is not needed for engines */
                        }

                        if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
                        if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
                        if (e->u.rail.railveh_type == RAILVEH_WAGON) {
                                if (!CargoSpec::Get(cargo_type)->is_freight) {
                                        if (parent_engine_type == INVALID_ENGINE) {
                                                return LS_PASSENGER_WAGON_STEAM;
                                        } else {
                                                switch (RailVehInfo(parent_engine_type)->engclass) {
                                                        default: NOT_REACHED();
                                                        case EC_STEAM:    return LS_PASSENGER_WAGON_STEAM;
                                                        case EC_DIESEL:   return LS_PASSENGER_WAGON_DIESEL;
                                                        case EC_ELECTRIC: return LS_PASSENGER_WAGON_ELECTRIC;
                                                        case EC_MONORAIL: return LS_PASSENGER_WAGON_MONORAIL;
                                                        case EC_MAGLEV:   return LS_PASSENGER_WAGON_MAGLEV;
                                                }
                                        }
                                } else {
                                        return LS_FREIGHT_WAGON;
                                }
                        } else {
                                bool is_mu = HasBit(e->info.misc_flags, EF_RAIL_IS_MU);

                                switch (e->u.rail.engclass) {
                                        default: NOT_REACHED();
                                        case EC_STEAM:    return LS_STEAM;
                                        case EC_DIESEL:   return is_mu ? LS_DMU : LS_DIESEL;
                                        case EC_ELECTRIC: return is_mu ? LS_EMU : LS_ELECTRIC;
                                        case EC_MONORAIL: return LS_MONORAIL;
                                        case EC_MAGLEV:   return LS_MAGLEV;
                                }
                        }

                case VEH_ROAD:
                        /* Always use the livery of the front */
                        if (v != NULL && parent_engine_type != INVALID_ENGINE) {
                                engine_type = parent_engine_type;
                                e = Engine::Get(engine_type);
                                cargo_type = v->First()->cargo_type;
                        }
                        if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
                        if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo

                        /* Important: Use Tram Flag of front part. Luckily engine_type refers to the front part here. */
                        if (HasBit(e->info.misc_flags, EF_ROAD_TRAM)) {
                                /* Tram */
                                return IsCargoInClass(cargo_type, CC_PASSENGERS) ? LS_PASSENGER_TRAM : LS_FREIGHT_TRAM;
                        } else {
                                /* Bus or truck */
                                return IsCargoInClass(cargo_type, CC_PASSENGERS) ? LS_BUS : LS_TRUCK;
                        }

                case VEH_SHIP:
                        if (cargo_type == CT_INVALID) cargo_type = e->GetDefaultCargoType();
                        if (cargo_type == CT_INVALID) cargo_type = CT_GOODS; // The vehicle does not carry anything, let's pick some freight cargo
                        return IsCargoInClass(cargo_type, CC_PASSENGERS) ? LS_PASSENGER_SHIP : LS_FREIGHT_SHIP;

                case VEH_AIRCRAFT:
                        switch (e->u.air.subtype) {
                                case AIR_HELI: return LS_HELICOPTER;
                                case AIR_CTOL: return LS_SMALL_PLANE;
                                case AIR_CTOL | AIR_FAST: return LS_LARGE_PLANE;
                                default: NOT_REACHED();
                        }
        }
}

/**
 * Determines the livery for a vehicle.
 * @param engine_type EngineID of the vehicle
 * @param company Owner of the vehicle
 * @param parent_engine_type EngineID of the front vehicle. INVALID_VEHICLE if vehicle is at front itself.
 * @param v the vehicle. NULL if in purchase list etc.
 * @param livery_setting The livery settings to use for acquiring the livery information.
 * @return livery to use
 */
const Livery *GetEngineLivery(EngineID engine_type, CompanyID company, EngineID parent_engine_type, const Vehicle *v, byte livery_setting)
{
        const Company *c = Company::Get(company);
        LiveryScheme scheme = LS_DEFAULT;

        /* The default livery is always available for use, but its in_use flag determines
         * whether any _other_ liveries are in use. */
        if (c->livery[LS_DEFAULT].in_use && (livery_setting == LIT_ALL || (livery_setting == LIT_COMPANY && company == _local_company))) {
                /* Determine the livery scheme to use */
                scheme = GetEngineLiveryScheme(engine_type, parent_engine_type, v);

                /* Switch back to the default scheme if the resolved scheme is not in use */
                if (!c->livery[scheme].in_use) scheme = LS_DEFAULT;
        }

        return &c->livery[scheme];
}


static PaletteID GetEngineColourMap(EngineID engine_type, CompanyID company, EngineID parent_engine_type, const Vehicle *v)
{
        PaletteID map = (v != NULL) ? v->colourmap : PAL_NONE;

        /* Return cached value if any */
        if (map != PAL_NONE) return map;

        const Engine *e = Engine::Get(engine_type);

        /* Check if we should use the colour map callback */
        if (HasBit(e->info.callback_mask, CBM_VEHICLE_COLOUR_REMAP)) {
                uint16 callback = GetVehicleCallback(CBID_VEHICLE_COLOUR_MAPPING, 0, 0, engine_type, v);
                /* Failure means "use the default two-colour" */
                if (callback != CALLBACK_FAILED) {
                        assert_compile(PAL_NONE == 0); // Returning 0x4000 (resp. 0xC000) coincidences with default value (PAL_NONE)
                        map = GB(callback, 0, 14);
                        /* If bit 14 is set, then the company colours are applied to the
                         * map else it's returned as-is. */
                        if (!HasBit(callback, 14)) {
                                /* Update cache */
                                if (v != NULL) const_cast<Vehicle *>(v)->colourmap = map;
                                return map;
                        }
                }
        }

        bool twocc = HasBit(e->info.misc_flags, EF_USES_2CC);

        if (map == PAL_NONE) map = twocc ? (PaletteID)SPR_2CCMAP_BASE : (PaletteID)PALETTE_RECOLOUR_START;

        /* Spectator has news shown too, but has invalid company ID - as well as dedicated server */
        if (!Company::IsValidID(company)) return map;

        const Livery *livery = GetEngineLivery(engine_type, company, parent_engine_type, v, _settings_client.gui.liveries);

        map += livery->colour1;
        if (twocc) map += livery->colour2 * 16;

        /* Update cache */
        if (v != NULL) const_cast<Vehicle *>(v)->colourmap = map;
        return map;
}

/**
 * Get the colour map for an engine. This used for unbuilt engines in the user interface.
 * @param engine_type ID of engine
 * @param company ID of company
 * @return A ready-to-use palette modifier
 */
PaletteID GetEnginePalette(EngineID engine_type, CompanyID company)
{
        return GetEngineColourMap(engine_type, company, INVALID_ENGINE, NULL);
}

/**
 * Get the colour map for a vehicle.
 * @param v Vehicle to get colour map for
 * @return A ready-to-use palette modifier
 */
PaletteID GetVehiclePalette(const Vehicle *v)
{
        if (v->IsGroundVehicle()) {
                return GetEngineColourMap(v->engine_type, v->owner, v->GetGroundVehicleCache()->first_engine, v);
        }

        return GetEngineColourMap(v->engine_type, v->owner, INVALID_ENGINE, v);
}

/**
 * Delete all implicit orders which were not reached.
 */
void Vehicle::DeleteUnreachedImplicitOrders()
{
        if (this->IsGroundVehicle()) {
                uint16 &gv_flags = this->GetGroundVehicleFlags();
                if (HasBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS)) {
                        /* Do not delete orders, only skip them */
                        ClrBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
                        this->cur_implicit_order_index = this->cur_real_order_index;
                        InvalidateVehicleOrder(this, 0);
                        return;
                }
        }

        const Order *order = this->GetOrder(this->cur_implicit_order_index);
        while (order != NULL) {
                if (this->cur_implicit_order_index == this->cur_real_order_index) break;

                if (order->IsType(OT_IMPLICIT)) {
                        DeleteOrder(this, this->cur_implicit_order_index);
                        /* DeleteOrder does various magic with order_indices, so resync 'order' with 'cur_implicit_order_index' */
                        order = this->GetOrder(this->cur_implicit_order_index);
                } else {
                        /* Skip non-implicit orders, e.g. service-orders */
                        order = order->next;
                        this->cur_implicit_order_index++;
                }

                /* Wrap around */
                if (order == NULL) {
                        order = this->GetOrder(0);
                        this->cur_implicit_order_index = 0;
                }
        }
}

/**
 * Prepare everything to begin the loading when arriving at a station.
 * @pre IsStationTile(this->tile) || this->type == VEH_SHIP.
 */
void Vehicle::BeginLoading()
{
        assert(IsStationTile(this->tile) || this->type == VEH_SHIP);

        if (this->current_order.IsType(OT_GOTO_STATION) &&
                        this->current_order.GetDestination() == this->last_station_visited) {
                this->DeleteUnreachedImplicitOrders();

                /* Now both order indices point to the destination station, and we can start loading */
                this->current_order.MakeLoading(true);
                UpdateVehicleTimetable(this, true);

                /* Furthermore add the Non Stop flag to mark that this station
                 * is the actual destination of the vehicle, which is (for example)
                 * necessary to be known for HandleTrainLoading to determine
                 * whether the train is lost or not; not marking a train lost
                 * that arrives at random stations is bad. */
                this->current_order.SetNonStopType(ONSF_NO_STOP_AT_ANY_STATION);

        } else {
                /* We weren't scheduled to stop here. Insert an implicit order
                 * to show that we are stopping here.
                 * While only groundvehicles have implicit orders, e.g. aircraft might still enter
                 * the 'wrong' terminal when skipping orders etc. */
                Order *in_list = this->GetOrder(this->cur_implicit_order_index);
                if (this->IsGroundVehicle() &&
                                (in_list == NULL || !in_list->IsType(OT_IMPLICIT) ||
                                in_list->GetDestination() != this->last_station_visited)) {
                        bool suppress_implicit_orders = HasBit(this->GetGroundVehicleFlags(), GVF_SUPPRESS_IMPLICIT_ORDERS);
                        /* Do not create consecutive duplicates of implicit orders */
                        Order *prev_order = this->cur_implicit_order_index > 0 ? this->GetOrder(this->cur_implicit_order_index - 1) : (this->GetNumOrders() > 1 ? this->GetLastOrder() : NULL);
                        if (prev_order == NULL ||
                                        (!prev_order->IsType(OT_IMPLICIT) && !prev_order->IsType(OT_GOTO_STATION)) ||
                                        prev_order->GetDestination() != this->last_station_visited) {

                                /* Prefer deleting implicit orders instead of inserting new ones,
                                 * so test whether the right order follows later. In case of only
                                 * implicit orders treat the last order in the list like an
                                 * explicit one, except if the overall number of orders surpasses
                                 * IMPLICIT_ORDER_ONLY_CAP. */
                                int target_index = this->cur_implicit_order_index;
                                bool found = false;
                                while (target_index != this->cur_real_order_index || this->GetNumManualOrders() == 0) {
                                        const Order *order = this->GetOrder(target_index);
                                        if (order == NULL) break; // No orders.
                                        if (order->IsType(OT_IMPLICIT) && order->GetDestination() == this->last_station_visited) {
                                                found = true;
                                                break;
                                        }
                                        target_index++;
                                        if (target_index >= this->orders.list->GetNumOrders()) {
                                                if (this->GetNumManualOrders() == 0 &&
                                                                this->GetNumOrders() < IMPLICIT_ORDER_ONLY_CAP) {
                                                        break;
                                                }
                                                target_index = 0;
                                        }
                                        if (target_index == this->cur_implicit_order_index) break; // Avoid infinite loop.
                                }

                                if (found) {
                                        if (suppress_implicit_orders) {
                                                /* Skip to the found order */
                                                this->cur_implicit_order_index = target_index;
                                                InvalidateVehicleOrder(this, 0);
                                        } else {
                                                /* Delete all implicit orders up to the station we just reached */
                                                const Order *order = this->GetOrder(this->cur_implicit_order_index);
                                                while (!order->IsType(OT_IMPLICIT) || order->GetDestination() != this->last_station_visited) {
                                                        if (order->IsType(OT_IMPLICIT)) {
                                                                DeleteOrder(this, this->cur_implicit_order_index);
                                                                /* DeleteOrder does various magic with order_indices, so resync 'order' with 'cur_implicit_order_index' */
                                                                order = this->GetOrder(this->cur_implicit_order_index);
                                                        } else {
                                                                /* Skip non-implicit orders, e.g. service-orders */
                                                                order = order->next;
                                                                this->cur_implicit_order_index++;
                                                        }

                                                        /* Wrap around */
                                                        if (order == NULL) {
                                                                order = this->GetOrder(0);
                                                                this->cur_implicit_order_index = 0;
                                                        }
                                                        assert(order != NULL);
                                                }
                                        }
                                } else if (!suppress_implicit_orders &&
                                                ((this->orders.list == NULL ? OrderList::CanAllocateItem() : this->orders.list->GetNumOrders() < MAX_VEH_ORDER_ID)) &&
                                                Order::CanAllocateItem()) {
                                        /* Insert new implicit order */
                                        Order *implicit_order = new Order();
                                        implicit_order->MakeImplicit(this->last_station_visited);
                                        InsertOrder(this, implicit_order, this->cur_implicit_order_index);
                                        if (this->cur_implicit_order_index > 0) --this->cur_implicit_order_index;

                                        /* InsertOrder disabled creation of implicit orders for all vehicles with the same implicit order.
                                         * Reenable it for this vehicle */
                                        uint16 &gv_flags = this->GetGroundVehicleFlags();
                                        ClrBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
                                }
                        }
                }
                this->current_order.MakeLoading(false);
        }

        if (this->last_loading_station != INVALID_STATION &&
                        this->last_loading_station != this->last_station_visited &&
                        ((this->current_order.GetLoadType() & OLFB_NO_LOAD) == 0 ||
                        (this->current_order.GetUnloadType() & OUFB_NO_UNLOAD) == 0)) {
                IncreaseStats(Station::Get(this->last_loading_station), this, this->last_station_visited);
        }

        PrepareUnload(this);

        SetWindowDirty(GetWindowClassForVehicleType(this->type), this->owner);
        SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
        SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
        SetWindowDirty(WC_STATION_VIEW, this->last_station_visited);

        Station::Get(this->last_station_visited)->MarkTilesDirty(true);
        this->cur_speed = 0;
        this->MarkDirty();
}

/**
 * Return all reserved cargo packets to the station and reset all packets
 * staged for transfer.
 * @param st the station where the reserved packets should go.
 */
void Vehicle::CancelReservation(StationID next, Station *st)
{
        for (Vehicle *v = this; v != NULL; v = v->next) {
                VehicleCargoList &cargo = v->cargo;
                if (cargo.ActionCount(VehicleCargoList::MTA_LOAD) > 0) {
                        DEBUG(misc, 1, "cancelling cargo reservation");
                        cargo.Return(UINT_MAX, &st->goods[v->cargo_type].cargo, next);
                        cargo.SetTransferLoadPlace(st->xy);
                }
                cargo.KeepAll();
        }
}

/**
 * Perform all actions when leaving a station.
 * @pre this->current_order.IsType(OT_LOADING)
 */
void Vehicle::LeaveStation()
{
        assert(this->current_order.IsType(OT_LOADING));

        delete this->cargo_payment;

        /* Only update the timetable if the vehicle was supposed to stop here. */
        if (this->current_order.GetNonStopType() != ONSF_STOP_EVERYWHERE) UpdateVehicleTimetable(this, false);

        if ((this->current_order.GetLoadType() & OLFB_NO_LOAD) == 0 ||
                        (this->current_order.GetUnloadType() & OUFB_NO_UNLOAD) == 0) {
                if (this->current_order.CanLeaveWithCargo(this->last_loading_station != INVALID_STATION)) {
                        /* Refresh next hop stats to make sure we've done that at least once
                         * during the stop and that refit_cap == cargo_cap for each vehicle in
                         * the consist. */
                        this->ResetRefitCaps();
                        LinkRefresher::Run(this);

                        /* if the vehicle could load here or could stop with cargo loaded set the last loading station */
                        this->last_loading_station = this->last_station_visited;
                } else {
                        /* if the vehicle couldn't load and had to unload or transfer everything
                         * set the last loading station to invalid as it will leave empty. */
                        this->last_loading_station = INVALID_STATION;
                }
        }

        this->current_order.MakeLeaveStation();
        Station *st = Station::Get(this->last_station_visited);
        this->CancelReservation(INVALID_STATION, st);
        st->loading_vehicles.remove(this);

        HideFillingPercent(&this->fill_percent_te_id);

        if (this->type == VEH_TRAIN && !(this->vehstatus & VS_CRASHED)) {
                /* Trigger station animation (trains only) */
                if (IsStationTile(this->tile)) {
                        TriggerStationRandomisation(st, this->tile, SRT_TRAIN_DEPARTS);
                        TriggerStationAnimation(st, this->tile, SAT_TRAIN_DEPARTS);
                }

                SetBit(Train::From(this)->flags, VRF_LEAVING_STATION);
        }

        this->MarkDirty();
}

/**
 * Reset all refit_cap in the consist to cargo_cap.
 */
void Vehicle::ResetRefitCaps()
{
        for (Vehicle *v = this; v != NULL; v = v->Next()) v->refit_cap = v->cargo_cap;
}

/**
 * Handle the loading of the vehicle; when not it skips through dummy
 * orders and does nothing in all other cases.
 * @param mode is the non-first call for this vehicle in this tick?
 */
void Vehicle::HandleLoading(bool mode)
{
        switch (this->current_order.GetType()) {
                case OT_LOADING: {
                        uint wait_time = max(this->current_order.wait_time - this->lateness_counter, 0);

                        /* Not the first call for this tick, or still loading */
                        if (mode || !HasBit(this->vehicle_flags, VF_LOADING_FINISHED) || this->current_order_time < wait_time) return;

                        this->PlayLeaveStationSound();

                        this->LeaveStation();

                        /* Only advance to next order if we just loaded at the current one */
                        const Order *order = this->GetOrder(this->cur_implicit_order_index);
                        if (order == NULL ||
                                        (!order->IsType(OT_IMPLICIT) && !order->IsType(OT_GOTO_STATION)) ||
                                        order->GetDestination() != this->last_station_visited) {
                                return;
                        }
                        break;
                }

                case OT_DUMMY: break;

                default: return;
        }

        this->IncrementImplicitOrderIndex();
}

/**
 * Get a map of cargoes and free capacities in the consist.
 * @param capacities Map to be filled with cargoes and capacities.
 */
void Vehicle::GetConsistFreeCapacities(SmallMap<CargoID, uint> &capacities) const
{
        for (const Vehicle *v = this; v != NULL; v = v->Next()) {
                if (v->cargo_cap == 0) continue;
                SmallPair<CargoID, uint> *pair = capacities.Find(v->cargo_type);
                if (pair == capacities.End()) {
                        pair = capacities.Append();
                        pair->first = v->cargo_type;
                        pair->second = v->cargo_cap - v->cargo.StoredCount();
                } else {
                        pair->second += v->cargo_cap - v->cargo.StoredCount();
                }
        }
}

uint Vehicle::GetConsistTotalCapacity() const
{
        uint result = 0;
        for (const Vehicle *v = this; v != NULL; v = v->Next()) {
                result += v->cargo_cap;
        }
        return result;
}

/**
 * Send this vehicle to the depot using the given command(s).
 * @param flags   the command flags (like execute and such).
 * @param command the command to execute.
 * @return the cost of the depot action.
 */
CommandCost Vehicle::SendToDepot(DoCommandFlag flags, DepotCommand command)
{
        CommandCost ret = CheckOwnership(this->owner);
        if (ret.Failed()) return ret;

        if (this->vehstatus & VS_CRASHED) return CMD_ERROR;
        if (this->IsStoppedInDepot()) return CMD_ERROR;

        if (this->current_order.IsType(OT_GOTO_DEPOT)) {
                bool halt_in_depot = (this->current_order.GetDepotActionType() & ODATFB_HALT) != 0;
                if (!!(command & DEPOT_SERVICE) == halt_in_depot) {
                        /* We called with a different DEPOT_SERVICE setting.
                         * Now we change the setting to apply the new one and let the vehicle head for the same depot.
                         * Note: the if is (true for requesting service == true for ordered to stop in depot)          */
                        if (flags & DC_EXEC) {
                                this->current_order.SetDepotOrderType(ODTF_MANUAL);
                                this->current_order.SetDepotActionType(halt_in_depot ? ODATF_SERVICE_ONLY : ODATFB_HALT);
                                SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
                        }
                        return CommandCost();
                }

                if (command & DEPOT_DONT_CANCEL) return CMD_ERROR; // Requested no cancelation of depot orders
                if (flags & DC_EXEC) {
                        /* If the orders to 'goto depot' are in the orders list (forced servicing),
                         * then skip to the next order; effectively cancelling this forced service */
                        if (this->current_order.GetDepotOrderType() & ODTFB_PART_OF_ORDERS) this->IncrementRealOrderIndex();

                        if (this->IsGroundVehicle()) {
                                uint16 &gv_flags = this->GetGroundVehicleFlags();
                                SetBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
                        }

                        this->current_order.MakeDummy();
                        SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);
                }
                return CommandCost();
        }

        TileIndex location;
        DestinationID destination;
        bool reverse;
        static const StringID no_depot[] = {STR_ERROR_UNABLE_TO_FIND_ROUTE_TO, STR_ERROR_UNABLE_TO_FIND_LOCAL_DEPOT, STR_ERROR_UNABLE_TO_FIND_LOCAL_DEPOT, STR_ERROR_CAN_T_SEND_AIRCRAFT_TO_HANGAR};
        if (!this->FindClosestDepot(&location, &destination, &reverse)) return_cmd_error(no_depot[this->type]);

        if (flags & DC_EXEC) {
                if (this->current_order.IsType(OT_LOADING)) this->LeaveStation();

                if (this->IsGroundVehicle() && this->GetNumManualOrders() > 0) {
                        uint16 &gv_flags = this->GetGroundVehicleFlags();
                        SetBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
                }

                this->dest_tile = location;
                this->current_order.MakeGoToDepot(destination, ODTF_MANUAL);
                if (!(command & DEPOT_SERVICE)) this->current_order.SetDepotActionType(ODATFB_HALT);
                SetWindowWidgetDirty(WC_VEHICLE_VIEW, this->index, WID_VV_START_STOP);

                /* If there is no depot in front, reverse automatically (trains only) */
                if (this->type == VEH_TRAIN && reverse) DoCommand(this->tile, this->index, 0, DC_EXEC, CMD_REVERSE_TRAIN_DIRECTION);

                if (this->type == VEH_AIRCRAFT) {
                        Aircraft *a = Aircraft::From(this);
                        if (a->state == FLYING && a->targetairport != destination) {
                                /* The aircraft is now heading for a different hangar than the next in the orders */
                                extern void AircraftNextAirportPos_and_Order(Aircraft *a);
                                AircraftNextAirportPos_and_Order(a);
                        }
                }
        }

        return CommandCost();

}

/**
 * Update the cached visual effect.
 * @param allow_power_change true if the wagon-is-powered-state may change.
 */
void Vehicle::UpdateVisualEffect(bool allow_power_change)
{
        bool powered_before = HasBit(this->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER);
        const Engine *e = this->GetEngine();

        /* Evaluate properties */
        byte visual_effect;
        switch (e->type) {
                case VEH_TRAIN: visual_effect = e->u.rail.visual_effect; break;
                case VEH_ROAD:  visual_effect = e->u.road.visual_effect; break;
                case VEH_SHIP:  visual_effect = e->u.ship.visual_effect; break;
                default:        visual_effect = 1 << VE_DISABLE_EFFECT;  break;
        }

        /* Check powered wagon / visual effect callback */
        if (HasBit(e->info.callback_mask, CBM_VEHICLE_VISUAL_EFFECT)) {
                uint16 callback = GetVehicleCallback(CBID_VEHICLE_VISUAL_EFFECT, 0, 0, this->engine_type, this);

                if (callback != CALLBACK_FAILED) {
                        if (callback >= 0x100 && e->GetGRF()->grf_version >= 8) ErrorUnknownCallbackResult(e->GetGRFID(), CBID_VEHICLE_VISUAL_EFFECT, callback);

                        callback = GB(callback, 0, 8);
                        /* Avoid accidentally setting 'visual_effect' to the default value
                         * Since bit 6 (disable effects) is set anyways, we can safely erase some bits. */
                        if (callback == VE_DEFAULT) {
                                assert(HasBit(callback, VE_DISABLE_EFFECT));
                                SB(callback, VE_TYPE_START, VE_TYPE_COUNT, 0);
                        }
                        visual_effect = callback;
                }
        }

        /* Apply default values */
        if (visual_effect == VE_DEFAULT ||
                        (!HasBit(visual_effect, VE_DISABLE_EFFECT) && GB(visual_effect, VE_TYPE_START, VE_TYPE_COUNT) == VE_TYPE_DEFAULT)) {
                /* Only train engines have default effects.
                 * Note: This is independent of whether the engine is a front engine or articulated part or whatever. */
                if (e->type != VEH_TRAIN || e->u.rail.railveh_type == RAILVEH_WAGON || !IsInsideMM(e->u.rail.engclass, EC_STEAM, EC_MONORAIL)) {
                        if (visual_effect == VE_DEFAULT) {
                                visual_effect = 1 << VE_DISABLE_EFFECT;
                        } else {
                                SetBit(visual_effect, VE_DISABLE_EFFECT);
                        }
                } else {
                        if (visual_effect == VE_DEFAULT) {
                                /* Also set the offset */
                                visual_effect = (VE_OFFSET_CENTRE - (e->u.rail.engclass == EC_STEAM ? 4 : 0)) << VE_OFFSET_START;
                        }
                        SB(visual_effect, VE_TYPE_START, VE_TYPE_COUNT, e->u.rail.engclass - EC_STEAM + VE_TYPE_STEAM);
                }
        }

        this->vcache.cached_vis_effect = visual_effect;

        if (!allow_power_change && powered_before != HasBit(this->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER)) {
                ToggleBit(this->vcache.cached_vis_effect, VE_DISABLE_WAGON_POWER);
                ShowNewGrfVehicleError(this->engine_type, STR_NEWGRF_BROKEN, STR_NEWGRF_BROKEN_POWERED_WAGON, GBUG_VEH_POWERED_WAGON, false);
        }
}

static const int8 _vehicle_smoke_pos[8] = {
        1, 1, 1, 0, -1, -1, -1, 0
};

/**
 * Draw visual effects (smoke and/or sparks) for a vehicle chain.
 * @pre this->IsPrimaryVehicle()
 */
void Vehicle::ShowVisualEffect() const
{
        assert(this->IsPrimaryVehicle());
        bool sound = false;

        /* Do not show any smoke when:
         * - vehicle smoke is disabled by the player
         * - the vehicle is slowing down or stopped (by the player)
         * - the vehicle is moving very slowly
         */
        if (_settings_game.vehicle.smoke_amount == 0 ||
                        this->vehstatus & (VS_TRAIN_SLOWING | VS_STOPPED) ||
                        this->cur_speed < 2) {
                return;
        }

        uint max_speed = this->vcache.cached_max_speed;
        if (this->type == VEH_TRAIN) {
                const Train *t = Train::From(this);
                /* For trains, do not show any smoke when:
                 * - the train is reversing
                 * - is entering a station with an order to stop there and its speed is equal to maximum station entering speed
                 */
                if (HasBit(t->flags, VRF_REVERSING) ||
                                (IsRailStationTile(t->tile) && t->IsFrontEngine() && t->current_order.ShouldStopAtStation(t, GetStationIndex(t->tile)) &&
                                t->cur_speed >= t->Train::GetCurrentMaxSpeed())) {
                        return;
                }

                max_speed = min(max_speed, t->gcache.cached_max_track_speed);
                max_speed = min(max_speed, this->current_order.max_speed);
        }
        if (this->type == VEH_ROAD || this->type == VEH_SHIP) max_speed = min(max_speed, this->current_order.max_speed * 2);

        const Vehicle *v = this;

        do {
                int effect_offset = GB(v->vcache.cached_vis_effect, VE_OFFSET_START, VE_OFFSET_COUNT) - VE_OFFSET_CENTRE;
                byte effect_type = GB(v->vcache.cached_vis_effect, VE_TYPE_START, VE_TYPE_COUNT);
                bool disable_effect = HasBit(v->vcache.cached_vis_effect, VE_DISABLE_EFFECT);

                /* Show no smoke when:
                 * - Smoke has been disabled for this vehicle
                 * - The vehicle is not visible
                 * - The vehicle is under a bridge
                 * - The vehicle is on a depot tile
                 * - The vehicle is on a tunnel tile
                 * - The vehicle is a train engine that is currently unpowered */
                if (disable_effect ||
                                v->vehstatus & VS_HIDDEN ||
                                HasBridgeAbove(v->tile) ||
                                IsDepotTile(v->tile) ||
                                IsTunnelTile(v->tile) ||
                                (v->type == VEH_TRAIN &&
                                !HasPowerOnRail(Train::From(v)->railtype, Train::From(v)->GetTrackRailType()))) {
                        continue;
                }

                /* The effect offset is relative to a point 4 units behind the vehicle's
                 * front (which is the center of an 8/8 vehicle). Shorter vehicles need a
                 * correction factor. */
                if (v->type == VEH_TRAIN) effect_offset += (VEHICLE_LENGTH - Train::From(v)->gcache.cached_veh_length) / 2;

                int x = _vehicle_smoke_pos[v->direction] * effect_offset;
                int y = _vehicle_smoke_pos[(v->direction + 2) % 8] * effect_offset;

                if (v->type == VEH_TRAIN && HasBit(Train::From(v)->flags, VRF_REVERSE_DIRECTION)) {
                        x = -x;
                        y = -y;
                }

                switch (effect_type) {
                        case VE_TYPE_STEAM:
                                /* Steam smoke - amount is gradually falling until vehicle reaches its maximum speed, after that it's normal.
                                 * Details: while vehicle's current speed is gradually increasing, steam plumes' density decreases by one third each
                                 * third of its maximum speed spectrum. Steam emission finally normalises at very close to vehicle's maximum speed.
                                 * REGULATION:
                                 * - instead of 1, 4 / 2^smoke_amount (max. 2) is used to provide sufficient regulation to steam puffs' amount. */
                                if (GB(v->tick_counter, 0, ((4 >> _settings_game.vehicle.smoke_amount) + ((this->cur_speed * 3) / max_speed))) == 0) {
                                        CreateEffectVehicleRel(v, x, y, 10, EV_STEAM_SMOKE);
                                        sound = true;
                                }
                                break;

                        case VE_TYPE_DIESEL: {
                                /* Diesel smoke - thicker when vehicle is starting, gradually subsiding till it reaches its maximum speed
                                 * when smoke emission stops.
                                 * Details: Vehicle's (max.) speed spectrum is divided into 32 parts. When max. speed is reached, chance for smoke
                                 * emission erodes by 32 (1/4). For trains, power and weight come in handy too to either increase smoke emission in
                                 * 6 steps (1000HP each) if the power is low or decrease smoke emission in 6 steps (512 tonnes each) if the train
                                 * isn't overweight. Power and weight contributions are expressed in a way that neither extreme power, nor
                                 * extreme weight can ruin the balance (e.g. FreightWagonMultiplier) in the formula. When the vehicle reaches
                                 * maximum speed no diesel_smoke is emitted.
                                 * REGULATION:
                                 * - up to which speed a diesel vehicle is emitting smoke (with reduced/small setting only until 1/2 of max_speed),
                                 * - in Chance16 - the last value is 512 / 2^smoke_amount (max. smoke when 128 = smoke_amount of 2). */
                                int power_weight_effect = 0;
                                if (v->type == VEH_TRAIN) {
                                        power_weight_effect = (32 >> (Train::From(this)->gcache.cached_power >> 10)) - (32 >> (Train::From(this)->gcache.cached_weight >> 9));
                                }
                                if (this->cur_speed < (max_speed >> (2 >> _settings_game.vehicle.smoke_amount)) &&
                                                Chance16((64 - ((this->cur_speed << 5) / max_speed) + power_weight_effect), (512 >> _settings_game.vehicle.smoke_amount))) {
                                        CreateEffectVehicleRel(v, x, y, 10, EV_DIESEL_SMOKE);
                                        sound = true;
                                }
                                break;
                        }

                        case VE_TYPE_ELECTRIC:
                                /* Electric train's spark - more often occurs when train is departing (more load)
                                 * Details: Electric locomotives are usually at least twice as powerful as their diesel counterparts, so spark
                                 * emissions are kept simple. Only when starting, creating huge force are sparks more likely to happen, but when
                                 * reaching its max. speed, quarter by quarter of it, chance decreases until the usual 2,22% at train's top speed.
                                 * REGULATION:
                                 * - in Chance16 the last value is 360 / 2^smoke_amount (max. sparks when 90 = smoke_amount of 2). */
                                if (GB(v->tick_counter, 0, 2) == 0 &&
                                                Chance16((6 - ((this->cur_speed << 2) / max_speed)), (360 >> _settings_game.vehicle.smoke_amount))) {
                                        CreateEffectVehicleRel(v, x, y, 10, EV_ELECTRIC_SPARK);
                                        sound = true;
                                }
                                break;

                        default:
                                break;
                }
        } while ((v = v->Next()) != NULL);

        if (sound) PlayVehicleSound(this, VSE_VISUAL_EFFECT);
}

/**
 * Set the next vehicle of this vehicle.
 * @param next the next vehicle. NULL removes the next vehicle.
 */
void Vehicle::SetNext(Vehicle *next)
{
        assert(this != next);

        if (this->next != NULL) {
                /* We had an old next vehicle. Update the first and previous pointers */
                for (Vehicle *v = this->next; v != NULL; v = v->Next()) {
                        v->first = this->next;
                }
                this->next->previous = NULL;
        }

        this->next = next;

        if (this->next != NULL) {
                /* A new next vehicle. Update the first and previous pointers */
                if (this->next->previous != NULL) this->next->previous->next = NULL;
                this->next->previous = this;
                for (Vehicle *v = this->next; v != NULL; v = v->Next()) {
                        v->first = this->first;
                }
        }
}

/**
 * Adds this vehicle to a shared vehicle chain.
 * @param shared_chain a vehicle of the chain with shared vehicles.
 * @pre !this->IsOrderListShared()
 */
void Vehicle::AddToShared(Vehicle *shared_chain)
{
        assert(this->previous_shared == NULL && this->next_shared == NULL);

        if (shared_chain->orders.list == NULL) {
                assert(shared_chain->previous_shared == NULL);
                assert(shared_chain->next_shared == NULL);
                this->orders.list = shared_chain->orders.list = new OrderList(NULL, shared_chain);
        }

        this->next_shared     = shared_chain->next_shared;
        this->previous_shared = shared_chain;

        shared_chain->next_shared = this;

        if (this->next_shared != NULL) this->next_shared->previous_shared = this;

        shared_chain->orders.list->AddVehicle(this);
}

/**
 * Removes the vehicle from the shared order list.
 */
void Vehicle::RemoveFromShared()
{
        /* Remember if we were first and the old window number before RemoveVehicle()
         * as this changes first if needed. */
        bool were_first = (this->FirstShared() == this);
        VehicleListIdentifier vli(VL_SHARED_ORDERS, this->type, this->owner, this->FirstShared()->index);

        this->orders.list->RemoveVehicle(this);

        if (!were_first) {
                /* We are not the first shared one, so only relink our previous one. */
                this->previous_shared->next_shared = this->NextShared();
        }

        if (this->next_shared != NULL) this->next_shared->previous_shared = this->previous_shared;


        if (this->orders.list->GetNumVehicles() == 1) {
                /* When there is only one vehicle, remove the shared order list window. */
                DeleteWindowById(GetWindowClassForVehicleType(this->type), vli.Pack());
                InvalidateVehicleOrder(this->FirstShared(), 0);
        } else if (were_first) {
                /* If we were the first one, update to the new first one.
                 * Note: FirstShared() is already the new first */
                InvalidateWindowData(GetWindowClassForVehicleType(this->type), vli.Pack(), this->FirstShared()->index | (1U << 31));
        }

        this->next_shared     = NULL;
        this->previous_shared = NULL;
}

void VehiclesYearlyLoop()
{
        Vehicle *v;
        FOR_ALL_VEHICLES(v) {
                if (v->IsPrimaryVehicle()) {
                        /* show warning if vehicle is not generating enough income last 2 years (corresponds to a red icon in the vehicle list) */
                        Money profit = v->GetDisplayProfitThisYear();
                        if (v->age >= 730 && profit < 0) {
                                if (_settings_client.gui.vehicle_income_warn && v->owner == _local_company) {
                                        SetDParam(0, v->index);
                                        SetDParam(1, profit);
                                        AddVehicleAdviceNewsItem(STR_NEWS_VEHICLE_IS_UNPROFITABLE, v->index);
                                }
                                AI::NewEvent(v->owner, new ScriptEventVehicleUnprofitable(v->index));
                        }

                        v->profit_last_year = v->profit_this_year;
                        v->profit_this_year = 0;
                        SetWindowDirty(WC_VEHICLE_DETAILS, v->index);
                }
        }
        GroupStatistics::UpdateProfits();
        SetWindowClassesDirty(WC_TRAINS_LIST);
        SetWindowClassesDirty(WC_SHIPS_LIST);
        SetWindowClassesDirty(WC_ROADVEH_LIST);
        SetWindowClassesDirty(WC_AIRCRAFT_LIST);
}


/**
 * Can this station be used by the given engine type?
 * @param engine_type the type of vehicles to test
 * @param st the station to test for
 * @return true if and only if the vehicle of the type can use this station.
 * @note For road vehicles the Vehicle is needed to determine whether it can
 *       use the station. This function will return true for road vehicles
 *       when at least one of the facilities is available.
 */
bool CanVehicleUseStation(EngineID engine_type, const Station *st)
{
        const Engine *e = Engine::GetIfValid(engine_type);
        assert(e != NULL);

        switch (e->type) {
                case VEH_TRAIN:
                        return (st->facilities & FACIL_TRAIN) != 0;

                case VEH_ROAD:
                        /* For road vehicles we need the vehicle to know whether it can actually
                         * use the station, but if it doesn't have facilities for RVs it is
                         * certainly not possible that the station can be used. */
                        return (st->facilities & (FACIL_BUS_STOP | FACIL_TRUCK_STOP)) != 0;

                case VEH_SHIP:
                        return (st->facilities & FACIL_DOCK) != 0;

                case VEH_AIRCRAFT:
                        return (st->facilities & FACIL_AIRPORT) != 0 &&
                                        (st->airport.GetFTA()->flags & (e->u.air.subtype & AIR_CTOL ? AirportFTAClass::AIRPLANES : AirportFTAClass::HELICOPTERS)) != 0;

                default:
                        return false;
        }
}

/**
 * Can this station be used by the given vehicle?
 * @param v the vehicle to test
 * @param st the station to test for
 * @return true if and only if the vehicle can use this station.
 */
bool CanVehicleUseStation(const Vehicle *v, const Station *st)
{
        if (v->type == VEH_ROAD) return st->GetPrimaryRoadStop(RoadVehicle::From(v)) != NULL;

        return CanVehicleUseStation(v->engine_type, st);
}

/**
 * Access the ground vehicle cache of the vehicle.
 * @pre The vehicle is a #GroundVehicle.
 * @return #GroundVehicleCache of the vehicle.
 */
GroundVehicleCache *Vehicle::GetGroundVehicleCache()
{
        assert(this->IsGroundVehicle());
        if (this->type == VEH_TRAIN) {
                return &Train::From(this)->gcache;
        } else {
                return &RoadVehicle::From(this)->gcache;
        }
}

/**
 * Access the ground vehicle cache of the vehicle.
 * @pre The vehicle is a #GroundVehicle.
 * @return #GroundVehicleCache of the vehicle.
 */
const GroundVehicleCache *Vehicle::GetGroundVehicleCache() const
{
        assert(this->IsGroundVehicle());
        if (this->type == VEH_TRAIN) {
                return &Train::From(this)->gcache;
        } else {
                return &RoadVehicle::From(this)->gcache;
        }
}

/**
 * Access the ground vehicle flags of the vehicle.
 * @pre The vehicle is a #GroundVehicle.
 * @return #GroundVehicleFlags of the vehicle.
 */
uint16 &Vehicle::GetGroundVehicleFlags()
{
        assert(this->IsGroundVehicle());
        if (this->type == VEH_TRAIN) {
                return Train::From(this)->gv_flags;
        } else {
                return RoadVehicle::From(this)->gv_flags;
        }
}

/**
 * Access the ground vehicle flags of the vehicle.
 * @pre The vehicle is a #GroundVehicle.
 * @return #GroundVehicleFlags of the vehicle.
 */
const uint16 &Vehicle::GetGroundVehicleFlags() const
{
        assert(this->IsGroundVehicle());
        if (this->type == VEH_TRAIN) {
                return Train::From(this)->gv_flags;
        } else {
                return RoadVehicle::From(this)->gv_flags;
        }
}

/**
 * Calculates the set of vehicles that will be affected by a given selection.
 * @param set [inout] Set of affected vehicles.
 * @param v First vehicle of the selection.
 * @param num_vehicles Number of vehicles in the selection (not counting articulated parts).
 * @pre \a set must be empty.
 * @post \a set will contain the vehicles that will be refitted.
 */
void GetVehicleSet(VehicleSet &set, Vehicle *v, uint8 num_vehicles)
{
        if (v->type == VEH_TRAIN) {
                Train *u = Train::From(v);
                /* Only include whole vehicles, so start with the first articulated part */
                u = u->GetFirstEnginePart();

                /* Include num_vehicles vehicles, not counting articulated parts */
                for (; u != NULL && num_vehicles > 0; num_vehicles--) {
                        do {
                                /* Include current vehicle in the selection. */
                                set.Include(u->index);

                                /* If the vehicle is multiheaded, add the other part too. */
                                if (u->IsMultiheaded()) set.Include(u->other_multiheaded_part->index);

                                u = u->Next();
                        } while (u != NULL && u->IsArticulatedPart());
                }
        }
}