Rearrange storage of reserved tracks for railway tiles

[openttd/fttd.git] / src / ship_cmd.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 ship_cmd.cpp Handling of ships. */

#include "stdafx.h"
#include "ship.h"
#include "landscape.h"
#include "timetable.h"
#include "news_func.h"
#include "company_func.h"
#include "depot_base.h"
#include "station_base.h"
#include "newgrf_engine.h"
#include "pathfinder/yapf/yapf.h"
#include "newgrf_sound.h"
#include "spritecache.h"
#include "strings_func.h"
#include "window_func.h"
#include "date_func.h"
#include "vehicle_func.h"
#include "sound_func.h"
#include "ai/ai.hpp"
#include "pathfinder/opf/opf_ship.h"
#include "engine_base.h"
#include "company_base.h"
#include "zoom_func.h"
#include "map/bridge.h"

#include "table/strings.h"

/**
 * Determine the effective #WaterClass for a ship travelling on a tile.
 * @param tile Tile of interest
 * @return the waterclass to be used by the ship.
 */
WaterClass GetEffectiveWaterClass(TileIndex tile)
{
        if (HasTileWaterClass(tile)) return GetWaterClass(tile);
        if (IsAqueductTile(tile)) return WATER_CLASS_CANAL;
        if (IsNormalRailTile(tile)) {
                assert(GetRailGroundType(tile) == RAIL_GROUND_WATER);
                return WATER_CLASS_SEA;
        }
        NOT_REACHED();
}

static const uint16 _ship_sprites[] = {0x0E5D, 0x0E55, 0x0E65, 0x0E6D};

template <>
bool IsValidImageIndex<VEH_SHIP>(uint8 image_index)
{
        return image_index < lengthof(_ship_sprites);
}

static inline TrackdirBits GetAvailShipTrackdirs(TileIndex tile, DiagDirection enterdir)
{
        return GetTileWaterwayStatus(tile) & DiagdirReachesTrackdirs(enterdir);
}

static SpriteID GetShipIcon(EngineID engine, EngineImageType image_type)
{
        const Engine *e = Engine::Get(engine);
        uint8 spritenum = e->u.ship.image_index;

        if (is_custom_sprite(spritenum)) {
                SpriteID sprite = GetCustomVehicleIcon(engine, DIR_W, image_type);
                if (sprite != 0) return sprite;

                spritenum = e->original_image_index;
        }

        assert(IsValidImageIndex<VEH_SHIP>(spritenum));
        return DIR_W + _ship_sprites[spritenum];
}

void DrawShipEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
{
        SpriteID sprite = GetShipIcon(engine, image_type);
        const Sprite *real_sprite = GetSprite(sprite, ST_NORMAL);
        preferred_x = Clamp(preferred_x, left - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI), right - UnScaleByZoom(real_sprite->width, ZOOM_LVL_GUI) - UnScaleByZoom(real_sprite->x_offs, ZOOM_LVL_GUI));
        DrawSprite(sprite, pal, preferred_x, y);
}

/**
 * Get the size of the sprite of a ship sprite heading west (used for lists).
 * @param engine The engine to get the sprite from.
 * @param[out] width The width of the sprite.
 * @param[out] height The height of the sprite.
 * @param[out] xoffs Number of pixels to shift the sprite to the right.
 * @param[out] yoffs Number of pixels to shift the sprite downwards.
 * @param image_type Context the sprite is used in.
 */
void GetShipSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
{
        const Sprite *spr = GetSprite(GetShipIcon(engine, image_type), ST_NORMAL);

        width  = UnScaleByZoom(spr->width, ZOOM_LVL_GUI);
        height = UnScaleByZoom(spr->height, ZOOM_LVL_GUI);
        xoffs  = UnScaleByZoom(spr->x_offs, ZOOM_LVL_GUI);
        yoffs  = UnScaleByZoom(spr->y_offs, ZOOM_LVL_GUI);
}

SpriteID Ship::GetImage(Direction direction, EngineImageType image_type) const
{
        uint8 spritenum = this->spritenum;

        if (is_custom_sprite(spritenum)) {
                SpriteID sprite = GetCustomVehicleSprite(this, direction, image_type);
                if (sprite != 0) return sprite;

                spritenum = this->GetEngine()->original_image_index;
        }

        assert(IsValidImageIndex<VEH_SHIP>(spritenum));
        return _ship_sprites[spritenum] + direction;
}

static const Depot *FindClosestShipDepot(const Vehicle *v, uint max_distance)
{
        /* Find the closest depot */
        const Depot *depot;
        const Depot *best_depot = NULL;
        /* If we don't have a maximum distance, i.e. distance = 0,
         * we want to find any depot so the best distance of no
         * depot must be more than any correct distance. On the
         * other hand if we have set a maximum distance, any depot
         * further away than max_distance can safely be ignored. */
        uint best_dist = max_distance == 0 ? UINT_MAX : max_distance + 1;

        FOR_ALL_DEPOTS(depot) {
                TileIndex tile = depot->xy;
                if (IsShipDepotTile(tile) && IsTileOwner(tile, v->owner)) {
                        uint dist = DistanceManhattan(tile, v->tile);
                        if (dist < best_dist) {
                                best_dist = dist;
                                best_depot = depot;
                        }
                }
        }

        return best_depot;
}

static void CheckIfShipNeedsService(Vehicle *v)
{
        if (Company::Get(v->owner)->settings.vehicle.servint_ships == 0 || !v->NeedsAutomaticServicing()) return;
        if (v->IsChainInDepot()) {
                VehicleServiceInDepot(v);
                return;
        }

        uint max_distance;
        switch (_settings_game.pf.pathfinder_for_ships) {
                case VPF_OPF:  max_distance = 12; break;
                case VPF_YAPF: max_distance = _settings_game.pf.yapf.maximum_go_to_depot_penalty / YAPF_TILE_LENGTH; break;
                default: NOT_REACHED();
        }

        const Depot *depot = FindClosestShipDepot(v, max_distance);

        if (depot == NULL) {
                if (v->current_order.IsType(OT_GOTO_DEPOT)) {
                        v->current_order.MakeDummy();
                        SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
                }
                return;
        }

        v->current_order.MakeGoToDepot(depot->index, ODTFB_SERVICE);
        v->dest_tile = depot->xy;
        SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
}

/**
 * Update the caches of this ship.
 */
void Ship::UpdateCache()
{
        const ShipVehicleInfo *svi = ShipVehInfo(this->engine_type);

        /* Get speed fraction for the current water type. Aqueducts are always canals. */
        bool is_ocean = GetEffectiveWaterClass(this->tile) == WATER_CLASS_SEA;
        uint raw_speed = GetVehicleProperty(this, PROP_SHIP_SPEED, svi->max_speed);
        this->vcache.cached_max_speed = svi->ApplyWaterClassSpeedFrac(raw_speed, is_ocean);

        /* Update cargo aging period. */
        this->vcache.cached_cargo_age_period = GetVehicleProperty(this, PROP_SHIP_CARGO_AGE_PERIOD, EngInfo(this->engine_type)->cargo_age_period);

        this->UpdateVisualEffect();
}

Money Ship::GetRunningCost() const
{
        const Engine *e = this->GetEngine();
        uint cost_factor = GetVehicleProperty(this, PROP_SHIP_RUNNING_COST_FACTOR, e->u.ship.running_cost);
        return GetPrice(PR_RUNNING_SHIP, cost_factor, e->GetGRF());
}

void Ship::OnNewDay()
{
        if ((++this->day_counter & 7) == 0) {
                DecreaseVehicleValue(this);
        }

        CheckVehicleBreakdown(this);
        AgeVehicle(this);
        CheckIfShipNeedsService(this);

        CheckOrders(this);

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

        CommandCost cost(EXPENSES_SHIP_RUN, this->GetRunningCost() * this->running_ticks / (DAYS_IN_YEAR * DAY_TICKS));

        this->profit_this_year -= cost.GetCost();
        this->running_ticks = 0;

        SubtractMoneyFromCompanyFract(this->owner, cost);

        SetWindowDirty(WC_VEHICLE_DETAILS, this->index);
        /* we need this for the profit */
        SetWindowClassesDirty(WC_SHIPS_LIST);
}

ShipPathPos Ship::GetPos() const
{
        if (this->vehstatus & VS_CRASHED) return ShipPathPos();

        Trackdir td;

        if (this->IsInDepot()) {
                /* We'll assume the ship is facing outwards */
                td = DiagDirToDiagTrackdir(GetShipDepotDirection(this->tile));
        } else if (this->trackdir == TRACKDIR_WORMHOLE) {
                /* ship on aqueduct, so just use his direction and assume a diagonal track */
                td = DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
        } else {
                td = this->trackdir;
        }

        return ShipPathPos(this->tile, td);
}

void Ship::MarkDirty()
{
        this->colourmap = PAL_NONE;
        this->UpdateViewport(true, false);
        this->UpdateCache();
}

static void PlayShipSound(const Vehicle *v)
{
        if (!PlayVehicleSound(v, VSE_START)) {
                SndPlayVehicleFx(ShipVehInfo(v->engine_type)->sfx, v);
        }
}

void Ship::PlayLeaveStationSound() const
{
        PlayShipSound(this);
}

TileIndex Ship::GetOrderStationLocation(StationID station)
{
        if (station == this->last_station_visited) this->last_station_visited = INVALID_STATION;

        const Station *st = Station::Get(station);
        if (!(st->facilities & FACIL_DOCK)) {
                this->IncrementRealOrderIndex();
                return 0;
        }

        return st->xy;
}

void Ship::UpdateDeltaXY(Direction direction)
{
        static const int8 _delta_xy_table[8][4] = {
                /* y_extent, x_extent, y_offs, x_offs */
                { 6,  6,  -3,  -3}, // N
                { 6, 32,  -3, -16}, // NE
                { 6,  6,  -3,  -3}, // E
                {32,  6, -16,  -3}, // SE
                { 6,  6,  -3,  -3}, // S
                { 6, 32,  -3, -16}, // SW
                { 6,  6,  -3,  -3}, // W
                {32,  6, -16,  -3}, // NW
        };

        const int8 *bb = _delta_xy_table[direction];
        this->x_offs        = bb[3];
        this->y_offs        = bb[2];
        this->x_extent      = bb[1];
        this->y_extent      = bb[0];
        this->z_extent      = 6;
}

static bool CheckShipLeaveDepot(Ship *v)
{
        if (!v->IsChainInDepot()) return false;

        /* We are leaving a depot, but have to go to the exact same one; re-enter */
        if (v->current_order.IsType(OT_GOTO_DEPOT) &&
                        IsShipDepotTile(v->tile) && GetDepotIndex(v->tile) == v->current_order.GetDestination()) {
                VehicleEnterDepot(v);
                return true;
        }

        TileIndex tile = v->tile;

        DiagDirection north_dir = GetShipDepotDirection(tile);
        TileIndex north_neighbour = TILE_ADD(tile, TileOffsByDiagDir(north_dir));
        DiagDirection south_dir = ReverseDiagDir(north_dir);
        TileIndex south_neighbour = TILE_ADD(tile, 2 * TileOffsByDiagDir(south_dir));

        TrackdirBits north_trackdirs = GetAvailShipTrackdirs(north_neighbour, north_dir);
        TrackdirBits south_trackdirs = GetAvailShipTrackdirs(south_neighbour, south_dir);
        if (north_trackdirs && south_trackdirs) {
                /* Ask pathfinder for best direction */
                bool reverse = false;
                bool path_found;
                switch (_settings_game.pf.pathfinder_for_ships) {
                        case VPF_OPF: reverse = OPFShipChooseTrack(v, north_neighbour, north_dir, north_trackdirs, path_found) == INVALID_TRACKDIR; break; // OPF always allows reversing
                        case VPF_YAPF: reverse = YapfShipCheckReverse(v); break;
                        default: NOT_REACHED();
                }
                if (reverse) north_trackdirs = TRACKDIR_BIT_NONE;
        }

        if (north_trackdirs) {
                /* Leave towards north */
                v->direction = DiagDirToDir(north_dir);
                v->trackdir = DiagDirToDiagTrackdir(north_dir);
        } else if (south_trackdirs) {
                /* Leave towards south */
                v->direction = DiagDirToDir(south_dir);
                v->trackdir = DiagDirToDiagTrackdir(south_dir);
        } else {
                /* Both ways blocked */
                return false;
        }

        v->vehstatus &= ~VS_HIDDEN;

        v->cur_speed = 0;
        v->UpdateViewport(true, true);
        SetWindowDirty(WC_VEHICLE_DEPOT, v->tile);

        PlayShipSound(v);
        VehicleServiceInDepot(v);
        InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
        SetWindowClassesDirty(WC_SHIPS_LIST);

        return false;
}

static bool ShipAccelerate(Vehicle *v)
{
        uint spd;
        byte t;

        spd = min(v->cur_speed + 1, v->vcache.cached_max_speed);
        spd = min(spd, v->current_order.max_speed * 2);

        /* updates statusbar only if speed have changed to save CPU time */
        if (spd != v->cur_speed) {
                v->cur_speed = spd;
                SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
        }

        /* Convert direction-independent speed into direction-dependent speed. (old movement method) */
        spd = v->GetOldAdvanceSpeed(spd);

        if (spd == 0) return false;
        if ((byte)++spd == 0) return true;

        v->progress = (t = v->progress) - (byte)spd;

        return (t < v->progress);
}

/**
 * Ship arrives at a dock. If it is the first time, send out a news item.
 * @param v  Ship that arrived.
 * @param st Station being visited.
 */
static void ShipArrivesAt(const Vehicle *v, Station *st)
{
        /* Check if station was ever visited before */
        if (!(st->had_vehicle_of_type & HVOT_SHIP)) {
                st->had_vehicle_of_type |= HVOT_SHIP;

                SetDParam(0, st->index);
                AddVehicleNewsItem(
                        STR_NEWS_FIRST_SHIP_ARRIVAL,
                        (v->owner == _local_company) ? NT_ARRIVAL_COMPANY : NT_ARRIVAL_OTHER,
                        v->index,
                        st->index
                );
                AI::NewEvent(v->owner, new ScriptEventStationFirstVehicle(st->index, v->index));
        }
}


/**
 * Runs the pathfinder to choose a trackdir to continue along.
 *
 * @param v Ship to navigate
 * @param tile Tile the ship is about to enter
 * @param enterdir Direction of entering
 * @param trackdirs Available trackdir choices on \a tile
 * @return Trackdir to choose, or INVALID_TRACKDIR when to reverse.
 */
static Trackdir ChooseShipTrack(Ship *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs)
{
        assert(IsValidDiagDirection(enterdir));

        bool path_found = true;
        Trackdir trackdir;
        switch (_settings_game.pf.pathfinder_for_ships) {
                case VPF_OPF: trackdir = OPFShipChooseTrack(v, tile, enterdir, trackdirs, path_found); break;
                case VPF_YAPF: trackdir = YapfShipChooseTrack(v, tile, enterdir, trackdirs, path_found); break;
                default: NOT_REACHED();
        }

        v->HandlePathfindingResult(path_found);
        return trackdir;
}

static const byte _ship_subcoord[TRACKDIR_END][3] = {
        {15, 8, 1},  // TRACKDIR_X_NE
        { 8, 0, 3},  // TRACKDIR_Y_SE
        { 7, 0, 2},  // TRACKDIR_UPPER_E
        {15, 8, 2},  // TRACKDIR_LOWER_E
        { 8, 0, 4},  // TRACKDIR_LEFT_S
        { 0, 8, 4},  // TRACKDIR_RIGHT_S
        { 0, 0, 0},
        { 0, 0, 0},
        { 0, 8, 5},  // TRACKDIR_X_SW
        { 8,15, 7},  // TRACKDIR_Y_NW
        { 0, 7, 6},  // TRACKDIR_UPPER_W
        { 8,15, 6},  // TRACKDIR_LOWER_W
        {15, 7, 0},  // TRACKDIR_LEFT_N
        { 7,15, 0},  // TRACKDIR_RIGHT_N
};

static void ShipController(Ship *v)
{
        v->tick_counter++;
        v->current_order_time++;

        if (v->HandleBreakdown()) return;

        if (v->vehstatus & VS_STOPPED) return;

        ProcessOrders(v);
        v->HandleLoading();

        if (v->current_order.IsType(OT_LOADING)) return;

        if (CheckShipLeaveDepot(v)) return;

        v->ShowVisualEffect();

        if (!ShipAccelerate(v)) return;

        VehiclePos gp = GetNewVehiclePos(v);
        if (v->trackdir == TRACKDIR_WORMHOLE) {
                /* On a bridge */
                if (gp.new_tile != v->tile) {
                        /* Still on the bridge */
                        v->x_pos = gp.x;
                        v->y_pos = gp.y;
                        VehicleUpdatePositionAndViewport(v);
                        return;
                } else {
                        v->trackdir = DiagDirToDiagTrackdir(ReverseDiagDir(GetTunnelBridgeDirection(v->tile)));
                }
        } else if (v->trackdir == TRACKDIR_DEPOT) {
                /* Inside depot */
                assert(gp.new_tile == v->tile);
                gp.x = v->x_pos;
                gp.y = v->y_pos;
        } else if (gp.new_tile == v->tile) {
                /* Not on a bridge or in a depot, staying in the old tile */

                /* A leave station order only needs one tick to get processed, so we can
                 * always skip ahead. */
                if (v->current_order.IsType(OT_LEAVESTATION)) {
                        v->current_order.Free();
                        SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
                } else if (v->dest_tile != 0) {
                        /* We have a target, let's see if we reached it... */
                        if (v->current_order.IsType(OT_GOTO_WAYPOINT) &&
                                        DistanceManhattan(v->dest_tile, gp.new_tile) <= 3) {
                                /* We got within 3 tiles of our target buoy, so let's skip to our
                                 * next order */
                                UpdateVehicleTimetable(v, true);
                                v->IncrementRealOrderIndex();
                                v->current_order.MakeDummy();
                        } else if (v->current_order.IsType(OT_GOTO_DEPOT)) {
                                if (v->dest_tile == gp.new_tile && (gp.x & 0xF) == 8 && (gp.y & 0xF) == 8) {
                                        VehicleEnterDepot(v);
                                        return;
                                }
                        } else if (v->current_order.IsType(OT_GOTO_STATION)) {
                                StationID sid = v->current_order.GetDestination();
                                Station *st = Station::Get(sid);
                                if (st->IsDockingTile(gp.new_tile)) {
                                        assert(st->facilities & FACIL_DOCK);
                                        v->last_station_visited = sid;
                                        /* Process station in the orderlist. */
                                        ShipArrivesAt(v, st);
                                        v->BeginLoading();
                                }
                        }
                }
        } else {
                /* Not on a bridge or in a depot, about to enter a new tile */

                if (!IsValidTile(gp.new_tile)) goto reverse_direction;

                DiagDirection diagdir = DiagdirBetweenTiles(v->tile, gp.new_tile);
                assert(diagdir != INVALID_DIAGDIR);

                if (IsAqueductTile(v->tile) && GetTunnelBridgeDirection(v->tile) == diagdir) {
                        TileIndex end_tile = GetOtherBridgeEnd(v->tile);
                        if (end_tile != gp.new_tile) {
                                /* Entering an aqueduct */
                                v->tile = end_tile;
                                v->trackdir = TRACKDIR_WORMHOLE;
                                v->x_pos = gp.x;
                                v->y_pos = gp.y;
                                VehicleUpdatePositionAndViewport(v);
                                return;
                        }
                }

                TrackdirBits trackdirs = GetAvailShipTrackdirs(gp.new_tile, diagdir);
                if (trackdirs == TRACKDIR_BIT_NONE) goto reverse_direction;

                /* Choose a direction, and continue if we find one */
                Trackdir trackdir = ChooseShipTrack(v, gp.new_tile, diagdir, trackdirs);
                if (trackdir == INVALID_TRACKDIR) goto reverse_direction;

                const byte *b = _ship_subcoord[trackdir];

                gp.x = (gp.x & ~0xF) | b[0];
                gp.y = (gp.y & ~0xF) | b[1];

                WaterClass old_wc = GetEffectiveWaterClass(v->tile);

                v->tile = gp.new_tile;
                v->trackdir = trackdir;

                /* Update ship cache when the water class changes. Aqueducts are always canals. */
                WaterClass new_wc = GetEffectiveWaterClass(gp.new_tile);
                if (old_wc != new_wc) v->UpdateCache();

                v->direction = (Direction)b[2];
        }

        /* update image of ship, as well as delta XY */
        v->x_pos = gp.x;
        v->y_pos = gp.y;
        v->z_pos = GetSlopePixelZ(gp.x, gp.y);

getout:
        VehicleUpdatePosition(v);
        v->UpdateViewport(true, true);
        return;

reverse_direction:
        v->direction = ReverseDir(v->direction);
        v->trackdir = ReverseTrackdir(v->trackdir);
        goto getout;
}

bool Ship::Tick()
{
        if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;

        ShipController(this);

        return true;
}

/**
 * Build a ship.
 * @param tile     tile of the depot where ship is built.
 * @param flags    type of operation.
 * @param e        the engine to build.
 * @param data     unused.
 * @param ret[out] the vehicle that has been built.
 * @return the cost of this operation or an error.
 */
CommandCost CmdBuildShip(TileIndex tile, DoCommandFlag flags, const Engine *e, uint16 data, Vehicle **ret)
{
        tile = GetShipDepotNorthTile(tile);
        if (flags & DC_EXEC) {
                int x;
                int y;

                const ShipVehicleInfo *svi = &e->u.ship;

                Ship *v = new Ship();
                *ret = v;

                v->owner = _current_company;
                v->tile = tile;
                x = TileX(tile) * TILE_SIZE + TILE_SIZE / 2;
                y = TileY(tile) * TILE_SIZE + TILE_SIZE / 2;
                v->x_pos = x;
                v->y_pos = y;
                v->z_pos = GetSlopePixelZ(x, y);

                v->UpdateDeltaXY(v->direction);
                v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;

                v->spritenum = svi->image_index;
                v->cargo_type = e->GetDefaultCargoType();
                v->cargo_cap = svi->capacity;
                v->refit_cap = 0;

                v->last_station_visited = INVALID_STATION;
                v->last_loading_station = INVALID_STATION;
                v->engine_type = e->index;

                v->reliability = e->reliability;
                v->reliability_spd_dec = e->reliability_spd_dec;
                v->max_age = e->GetLifeLengthInDays();
                _new_vehicle_id = v->index;

                v->trackdir = TRACKDIR_DEPOT;

                v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_ships);
                v->date_of_last_service = _date;
                v->build_year = _cur_year;
                v->cur_image = SPR_IMG_QUERY;
                v->random_bits = VehicleRandomBits();

                v->UpdateCache();

                if (e->flags & ENGINE_EXCLUSIVE_PREVIEW) SetBit(v->vehicle_flags, VF_BUILT_AS_PROTOTYPE);
                v->SetServiceIntervalIsPercent(Company::Get(_current_company)->settings.vehicle.servint_ispercent);

                v->InvalidateNewGRFCacheOfChain();

                v->cargo_cap = e->DetermineCapacity(v);

                v->InvalidateNewGRFCacheOfChain();

                VehicleUpdatePosition(v);
        }

        return CommandCost();
}

bool Ship::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
{
        const Depot *depot = FindClosestShipDepot(this, 0);

        if (depot == NULL) return false;

        if (location    != NULL) *location    = depot->xy;
        if (destination != NULL) *destination = depot->index;

        return true;
}