ship_cmd.cpp

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/*
 * 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/>.
 */
 
#include "stdafx.h"
#include "ship.h"
#include "landscape.h"
#include "timetable.h"
#include "news_func.h"
#include "company_func.h"
#include "pathfinder/npf/npf_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 "game/game.hpp"
#include "engine_base.h"
#include "company_base.h"
#include "tunnelbridge_map.h"
#include "zoom_func.h"
#include "framerate_type.h"
#include "industry.h"
#include "industry_map.h"
 
#include "table/strings.h"
 
#include "safeguards.h"
 
WaterClass GetEffectiveWaterClass(TileIndex tile)
{
  if (HasTileWaterClass(tile)) return GetWaterClass(tile);
  if (IsTileType(tile, MP_TUNNELBRIDGE)) {
    assert(GetTunnelBridgeTransportType(tile) == TRANSPORT_WATER);
    return WATER_CLASS_CANAL;
  }
  if (IsTileType(tile, MP_RAILWAY)) {
    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 TrackBits GetTileShipTrackStatus(TileIndex tile)
{
  return TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_WATER, 0));
}
 
static void GetShipIcon(EngineID engine, EngineImageType image_type, VehicleSpriteSeq *result)
{
  const Engine *e = Engine::Get(engine);
  uint8 spritenum = e->u.ship.image_index;
 
  if (is_custom_sprite(spritenum)) {
    GetCustomVehicleIcon(engine, DIR_W, image_type, result);
    if (result->IsValid()) return;
 
    spritenum = e->original_image_index;
  }
 
  assert(IsValidImageIndex<VEH_SHIP>(spritenum));
  result->Set(DIR_W + _ship_sprites[spritenum]);
}
 
void DrawShipEngine(int left, int right, int preferred_x, int y, EngineID engine, PaletteID pal, EngineImageType image_type)
{
  VehicleSpriteSeq seq;
  GetShipIcon(engine, image_type, &seq);
 
  Rect rect;
  seq.GetBounds(&rect);
  preferred_x = Clamp(preferred_x,
      left - UnScaleGUI(rect.left),
      right - UnScaleGUI(rect.right));
 
  seq.Draw(preferred_x, y, pal, pal == PALETTE_CRASH);
}
 
void GetShipSpriteSize(EngineID engine, uint &width, uint &height, int &xoffs, int &yoffs, EngineImageType image_type)
{
  VehicleSpriteSeq seq;
  GetShipIcon(engine, image_type, &seq);
 
  Rect rect;
  seq.GetBounds(&rect);
 
  width  = UnScaleGUI(rect.right - rect.left + 1);
  height = UnScaleGUI(rect.bottom - rect.top + 1);
  xoffs  = UnScaleGUI(rect.left);
  yoffs  = UnScaleGUI(rect.top);
}
 
void Ship::GetImage(Direction direction, EngineImageType image_type, VehicleSpriteSeq *result) const
{
  uint8 spritenum = this->spritenum;
 
  if (image_type == EIT_ON_MAP) direction = this->rotation;
 
  if (is_custom_sprite(spritenum)) {
    GetCustomVehicleSprite(this, direction, image_type, result);
    if (result->IsValid()) return;
 
    spritenum = this->GetEngine()->original_image_index;
  }
 
  assert(IsValidImageIndex<VEH_SHIP>(spritenum));
  result->Set(_ship_sprites[spritenum] + direction);
}
 
static const Depot *FindClosestShipDepot(const Vehicle *v, uint max_distance)
{
  /* Find the closest depot */
  const Depot *best_depot = nullptr;
  /* 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 (const Depot *depot : Depot::Iterate()) {
    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_NPF:  max_distance = _settings_game.pf.npf.maximum_go_to_depot_penalty  / NPF_TILE_LENGTH;  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 == nullptr) {
    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->SetDestTile(depot->xy);
  SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
}
 
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);
}
 
Trackdir Ship::GetVehicleTrackdir() const
{
  if (this->vehstatus & VS_CRASHED) return INVALID_TRACKDIR;
 
  if (this->IsInDepot()) {
    /* We'll assume the ship is facing outwards */
    return DiagDirToDiagTrackdir(GetShipDepotDirection(this->tile));
  }
 
  if (this->state == TRACK_BIT_WORMHOLE) {
    /* ship on aqueduct, so just use its direction and assume a diagonal track */
    return DiagDirToDiagTrackdir(DirToDiagDir(this->direction));
  }
 
  return TrackDirectionToTrackdir(FindFirstTrack(this->state), this->direction);
}
 
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 (CanVehicleUseStation(this, st)) {
    return st->xy;
  } else {
    this->IncrementRealOrderIndex();
    return 0;
  }
}
 
void Ship::UpdateDeltaXY()
{
  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[this->rotation];
  this->x_offs        = bb[3];
  this->y_offs        = bb[2];
  this->x_extent      = bb[1];
  this->y_extent      = bb[0];
  this->z_extent      = 6;
 
  if (this->direction != this->rotation) {
    /* If we are rotating, then it is possible the ship was moved to its next position. In that
     * case, because we are still showing the old direction, the ship will appear to glitch sideways
     * slightly. We can work around this by applying an additional offset to make the ship appear
     * where it was before it moved. */
    this->x_offs -= this->x_pos - this->rotation_x_pos;
    this->y_offs -= this->y_pos - this->rotation_y_pos;
  }
}
 
static Vehicle *EnsureNoMovingShipProc(Vehicle *v, void *data)
{
  return v->type == VEH_SHIP && (v->vehstatus & (VS_HIDDEN | VS_STOPPED)) == 0 ? v : nullptr;
}
 
static bool CheckReverseShip(const Ship *v, Trackdir *trackdir = nullptr)
{
  /* Ask pathfinder for best direction */
  bool reverse = false;
  switch (_settings_game.pf.pathfinder_for_ships) {
    case VPF_NPF: reverse = NPFShipCheckReverse(v, trackdir); break;
    case VPF_YAPF: reverse = YapfShipCheckReverse(v, trackdir); break;
    default: NOT_REACHED();
  }
  return reverse;
}
 
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;
  }
 
  /* Don't leave depot if no destination set */
  if (v->dest_tile == 0) return true;
 
  /* Don't leave depot if another vehicle is already entering/leaving */
  /* This helps avoid CPU load if many ships are set to start at the same time */
  if (HasVehicleOnPos(v->tile, nullptr, &EnsureNoMovingShipProc)) return true;
 
  TileIndex tile = v->tile;
  Axis axis = GetShipDepotAxis(tile);
 
  DiagDirection north_dir = ReverseDiagDir(AxisToDiagDir(axis));
  TileIndex north_neighbour = TILE_ADD(tile, TileOffsByDiagDir(north_dir));
  DiagDirection south_dir = AxisToDiagDir(axis);
  TileIndex south_neighbour = TILE_ADD(tile, 2 * TileOffsByDiagDir(south_dir));
 
  TrackBits north_tracks = DiagdirReachesTracks(north_dir) & GetTileShipTrackStatus(north_neighbour);
  TrackBits south_tracks = DiagdirReachesTracks(south_dir) & GetTileShipTrackStatus(south_neighbour);
  if (north_tracks && south_tracks) {
    if (CheckReverseShip(v)) north_tracks = TRACK_BIT_NONE;
  }
 
  if (north_tracks) {
    /* Leave towards north */
    v->rotation = v->direction = DiagDirToDir(north_dir);
  } else if (south_tracks) {
    /* Leave towards south */
    v->rotation = v->direction = DiagDirToDir(south_dir);
  } else {
    /* Both ways blocked */
    return false;
  }
 
  v->state = AxisToTrackBits(axis);
  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 = std::min<uint>(v->cur_speed + 1, v->vcache.cached_max_speed);
  spd = std::min<uint>(spd, v->current_order.GetMaxSpeed() * 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);
}
 
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));
    Game::NewEvent(new ScriptEventStationFirstVehicle(st->index, v->index));
  }
}
 
 
static Track ChooseShipTrack(Ship *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks)
{
  assert(IsValidDiagDirection(enterdir));
 
  bool path_found = true;
  Track track;
 
  if (v->dest_tile == 0) {
    /* No destination, don't invoke pathfinder. */
    track = TrackBitsToTrack(v->state);
    if (!IsDiagonalTrack(track)) track = TrackToOppositeTrack(track);
    if (!HasBit(tracks, track)) track = FindFirstTrack(tracks);
    path_found = false;
  } else {
    /* Attempt to follow cached path. */
    if (!v->path.empty()) {
      track = TrackdirToTrack(v->path.front());
 
      if (HasBit(tracks, track)) {
        v->path.pop_front();
        /* HandlePathfindResult() is not called here because this is not a new pathfinder result. */
        return track;
      }
 
      /* Cached path is invalid so continue with pathfinder. */
      v->path.clear();
    }
 
    switch (_settings_game.pf.pathfinder_for_ships) {
      case VPF_NPF: track = NPFShipChooseTrack(v, path_found); break;
      case VPF_YAPF: track = YapfShipChooseTrack(v, tile, enterdir, tracks, path_found, v->path); break;
      default: NOT_REACHED();
    }
  }
 
  v->HandlePathfindingResult(path_found);
  return track;
}
 
static inline TrackBits GetAvailShipTracks(TileIndex tile, DiagDirection dir)
{
  TrackBits tracks = GetTileShipTrackStatus(tile) & DiagdirReachesTracks(dir);
 
  return tracks;
}
 
static const byte _ship_subcoord[4][6][3] = {
  {
    {15, 8, 1},
    { 0, 0, 0},
    { 0, 0, 0},
    {15, 8, 2},
    {15, 7, 0},
    { 0, 0, 0},
  },
  {
    { 0, 0, 0},
    { 8, 0, 3},
    { 7, 0, 2},
    { 0, 0, 0},
    { 8, 0, 4},
    { 0, 0, 0},
  },
  {
    { 0, 8, 5},
    { 0, 0, 0},
    { 0, 7, 6},
    { 0, 0, 0},
    { 0, 0, 0},
    { 0, 8, 4},
  },
  {
    { 0, 0, 0},
    { 8, 15, 7},
    { 0, 0, 0},
    { 8, 15, 6},
    { 0, 0, 0},
    { 7, 15, 0},
  }
};
 
static int ShipTestUpDownOnLock(const Ship *v)
{
  /* Suitable tile? */
  if (!IsTileType(v->tile, MP_WATER) || !IsLock(v->tile) || GetLockPart(v->tile) != LOCK_PART_MIDDLE) return 0;
 
  /* Must be at the centre of the lock */
  if ((v->x_pos & 0xF) != 8 || (v->y_pos & 0xF) != 8) return 0;
 
  DiagDirection diagdir = GetInclinedSlopeDirection(GetTileSlope(v->tile));
  assert(IsValidDiagDirection(diagdir));
 
  if (DirToDiagDir(v->direction) == diagdir) {
    /* Move up */
    return (v->z_pos < GetTileMaxZ(v->tile) * (int)TILE_HEIGHT) ? 1 : 0;
  } else {
    /* Move down */
    return (v->z_pos > GetTileZ(v->tile) * (int)TILE_HEIGHT) ? -1 : 0;
  }
}
 
static bool ShipMoveUpDownOnLock(Ship *v)
{
  /* Moving up/down through lock */
  int dz = ShipTestUpDownOnLock(v);
  if (dz == 0) return false;
 
  if (v->cur_speed != 0) {
    v->cur_speed = 0;
    SetWindowWidgetDirty(WC_VEHICLE_VIEW, v->index, WID_VV_START_STOP);
  }
 
  if ((v->tick_counter & 7) == 0) {
    v->z_pos += dz;
    v->UpdatePosition();
    v->UpdateViewport(true, true);
  }
 
  return true;
}
 
bool IsShipDestinationTile(TileIndex tile, StationID station)
{
  assert(IsDockingTile(tile));
  /* Check each tile adjacent to docking tile. */
  for (DiagDirection d = DIAGDIR_BEGIN; d != DIAGDIR_END; d++) {
    TileIndex t = tile + TileOffsByDiagDir(d);
    if (!IsValidTile(t)) continue;
    if (IsDockTile(t) && GetStationIndex(t) == station && IsValidDockingDirectionForDock(t, d)) return true;
    if (IsTileType(t, MP_INDUSTRY)) {
      const Industry *i = Industry::GetByTile(t);
      if (i->neutral_station != nullptr && i->neutral_station->index == station) return true;
    }
    if (IsTileType(t, MP_STATION) && IsOilRig(t) && GetStationIndex(t) == station) return true;
  }
  return false;
}
 
static void ShipController(Ship *v)
{
  uint32 r;
  const byte *b;
  Track track;
  TrackBits tracks;
  GetNewVehiclePosResult gp;
 
  v->tick_counter++;
  v->current_order_time++;
 
  if (v->HandleBreakdown()) return;
 
  if (v->vehstatus & VS_STOPPED) return;
 
  if (ProcessOrders(v) && CheckReverseShip(v)) goto reverse_direction;
 
  v->HandleLoading();
 
  if (v->current_order.IsType(OT_LOADING)) return;
 
  if (CheckShipLeaveDepot(v)) return;
 
  v->ShowVisualEffect();
 
  /* Rotating on spot */
  if (v->direction != v->rotation) {
    if ((v->tick_counter & 7) == 0) {
      DirDiff diff = DirDifference(v->direction, v->rotation);
      v->rotation = ChangeDir(v->rotation, diff > DIRDIFF_REVERSE ? DIRDIFF_45LEFT : DIRDIFF_45RIGHT);
      /* Invalidate the sprite cache direction to force recalculation of viewport */
      v->sprite_cache.last_direction = INVALID_DIR;
      v->UpdateViewport(true, true);
    }
    return;
  }
 
  if (ShipMoveUpDownOnLock(v)) return;
 
  if (!ShipAccelerate(v)) return;
 
  gp = GetNewVehiclePos(v);
  if (v->state != TRACK_BIT_WORMHOLE) {
    /* Not on a bridge */
    if (gp.old_tile == gp.new_tile) {
      /* Staying in tile */
      if (v->IsInDepot()) {
        gp.x = v->x_pos;
        gp.y = v->y_pos;
      } else {
        /* Not inside depot */
        r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
        if (HasBit(r, VETS_CANNOT_ENTER)) goto reverse_direction;
 
        /* 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);
          /* Test if continuing forward would lead to a dead-end, moving into the dock. */
          DiagDirection exitdir = VehicleExitDir(v->direction, v->state);
          TileIndex tile = TileAddByDiagDir(v->tile, exitdir);
          if (TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_WATER, 0, exitdir)) == TRACK_BIT_NONE) goto reverse_direction;
        } 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) &&
            v->dest_tile == gp.new_tile) {
            /* Depot orders really need to reach the tile */
            if ((gp.x & 0xF) == 8 && (gp.y & 0xF) == 8) {
              VehicleEnterDepot(v);
              return;
            }
          } else if (v->current_order.IsType(OT_GOTO_STATION) && IsDockingTile(gp.new_tile)) {
            /* Process station in the orderlist. */
            Station *st = Station::Get(v->current_order.GetDestination());
            if (st->docking_station.Contains(gp.new_tile) && IsShipDestinationTile(gp.new_tile, st->index)) {
              v->last_station_visited = st->index;
              if (st->facilities & FACIL_DOCK) { // ugly, ugly workaround for problem with ships able to drop off cargo at wrong stations
                ShipArrivesAt(v, st);
                v->BeginLoading();
              } else { // leave stations without docks right away
                v->current_order.MakeLeaveStation();
                v->IncrementRealOrderIndex();
              }
            }
          }
        }
      }
    } else {
      /* New tile */
      if (!IsValidTile(gp.new_tile)) goto reverse_direction;
 
      DiagDirection diagdir = DiagdirBetweenTiles(gp.old_tile, gp.new_tile);
      assert(diagdir != INVALID_DIAGDIR);
      tracks = GetAvailShipTracks(gp.new_tile, diagdir);
      if (tracks == TRACK_BIT_NONE) {
        Trackdir trackdir = INVALID_TRACKDIR;
        CheckReverseShip(v, &trackdir);
        if (trackdir == INVALID_TRACKDIR) goto reverse_direction;
        static const Direction _trackdir_to_direction[] = {
          DIR_NE, DIR_SE, DIR_E, DIR_E, DIR_S, DIR_S, INVALID_DIR, INVALID_DIR,
          DIR_SW, DIR_NW, DIR_W, DIR_W, DIR_N, DIR_N, INVALID_DIR, INVALID_DIR,
        };
        v->direction = _trackdir_to_direction[trackdir];
        assert(v->direction != INVALID_DIR);
        v->state = TrackdirBitsToTrackBits(TrackdirToTrackdirBits(trackdir));
        goto direction_changed;
      }
 
      /* Choose a direction, and continue if we find one */
      track = ChooseShipTrack(v, gp.new_tile, diagdir, tracks);
      if (track == INVALID_TRACK) goto reverse_direction;
 
      b = _ship_subcoord[diagdir][track];
 
      gp.x = (gp.x & ~0xF) | b[0];
      gp.y = (gp.y & ~0xF) | b[1];
 
      /* Call the landscape function and tell it that the vehicle entered the tile */
      r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
      if (HasBit(r, VETS_CANNOT_ENTER)) goto reverse_direction;
 
      if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
        v->tile = gp.new_tile;
        v->state = TrackToTrackBits(track);
 
        /* Update ship cache when the water class changes. Aqueducts are always canals. */
        WaterClass old_wc = GetEffectiveWaterClass(gp.old_tile);
        WaterClass new_wc = GetEffectiveWaterClass(gp.new_tile);
        if (old_wc != new_wc) v->UpdateCache();
      }
 
      Direction new_direction = (Direction)b[2];
      DirDiff diff = DirDifference(new_direction, v->direction);
      switch (diff) {
        case DIRDIFF_SAME:
        case DIRDIFF_45RIGHT:
        case DIRDIFF_45LEFT:
          /* Continue at speed */
          v->rotation = v->direction = new_direction;
          break;
 
        default:
          /* Stop for rotation */
          v->cur_speed = 0;
          v->direction = new_direction;
          /* Remember our current location to avoid movement glitch */
          v->rotation_x_pos = v->x_pos;
          v->rotation_y_pos = v->y_pos;
          break;
      }
    }
  } else {
    /* On a bridge */
    if (!IsTileType(gp.new_tile, MP_TUNNELBRIDGE) || !HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
      v->x_pos = gp.x;
      v->y_pos = gp.y;
      v->UpdatePosition();
      if ((v->vehstatus & VS_HIDDEN) == 0) v->Vehicle::UpdateViewport(true);
      return;
    }
 
    /* Ship is back on the bridge head, we need to consume its path
     * cache entry here as we didn't have to choose a ship track. */
    if (!v->path.empty()) v->path.pop_front();
  }
 
  /* update image of ship, as well as delta XY */
  v->x_pos = gp.x;
  v->y_pos = gp.y;
 
getout:
  v->UpdatePosition();
  v->UpdateViewport(true, true);
  return;
 
reverse_direction:
  v->direction = ReverseDir(v->direction);
direction_changed:
  /* Remember our current location to avoid movement glitch */
  v->rotation_x_pos = v->x_pos;
  v->rotation_y_pos = v->y_pos;
  v->cur_speed = 0;
  v->path.clear();
  goto getout;
}
 
bool Ship::Tick()
{
  PerformanceAccumulator framerate(PFE_GL_SHIPS);
 
  if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
 
  ShipController(this);
 
  return true;
}
 
void Ship::SetDestTile(TileIndex tile)
{
  if (tile == this->dest_tile) return;
  this->path.clear();
  this->dest_tile = tile;
}
 
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->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->state = TRACK_BIT_DEPOT;
 
    v->SetServiceInterval(Company::Get(_current_company)->settings.vehicle.servint_ships);
    v->date_of_last_service = _date;
    v->build_year = _cur_year;
    v->sprite_cache.sprite_seq.Set(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();
 
    v->UpdatePosition();
  }
 
  return CommandCost();
}
 
bool Ship::FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse)
{
  const Depot *depot = FindClosestShipDepot(this, 0);
 
  if (depot == nullptr) return false;
 
  if (location    != nullptr) *location    = depot->xy;
  if (destination != nullptr) *destination = depot->index;
 
  return true;
}