*     that handles the vehicle's ticks.

 * <li>Run the disaster vehicles each tick until their target has been reached,

 *     this happens in the DisasterTick_XXX() functions. In here, a vehicle's

 *     will increase this value, and the last one will remove the disaster itself

 * </ol>

 */

	this->UpdateDeltaXY();

	this->owner = OWNER_NONE;

	this->image_override = 0;

	this->UpdateImage();

	this->UpdatePositionAndViewport();

}

/**

 * 0: Zeppeliner initialization has found a small airport, go there and crash

 * 1: Create crash and animate falling down for extra dramatic effect

 * 2: Create more smoke and leave debris on ground

{

	v->tick_counter++;

		if (HasBit(v->tick_counter, 0)) return true;

		GetNewVehiclePosResult gp = GetNewVehiclePos(v);

		v->UpdatePosition(gp.x, gp.y, GetAircraftFlightLevel(v));

			if (++v->age == 38) {

				v->age = 0;

			}

			if (GB(v->tick_counter, 0, 3) == 0) CreateEffectVehicleRel(v, 0, -17, 2, EV_CRASH_SMOKE);

			if (IsValidTile(v->tile) && IsAirportTile(v->tile)) {

				v->age = 0;

				SetDParam(0, GetStationIndex(v->tile));

		return true;

	}

		if (++v->age <= 13320) return true;

		if (IsValidTile(v->tile) && IsAirportTile(v->tile)) {

				EV_EXPLOSION_SMALL);

		}

	} else if (v->age == 350) {

		v->age = 0;

	}

}

/**

 * 0: Fly around to the middle of the map, then randomly, after a while target a road vehicle

 * 1: Home in on a road vehicle and crash it >:)

 * If not road vehicle was found, only state 0 is used and Ufo disappears after a while

{

	v->image_override = (HasBit(++v->tick_counter, 3)) ? SPR_UFO_SMALL_SCOUT_DARKER : SPR_UFO_SMALL_SCOUT;

		/* Fly around randomly */

		int x = TileX(v->dest_tile) * TILE_SIZE;

		int y = TileY(v->dest_tile) * TILE_SIZE;

			v->dest_tile = RandomTile();

			return true;

		}

		uint n = 0; // Total number of targetable road vehicles.

		for (const RoadVehicle *u : RoadVehicle::Iterate()) {

}

/**

 * 0: Fly towards the targeted industry

 * 1: If within 15 tiles, fire away rockets and destroy industry

 * 2: Industry explosions

static bool DisasterTick_Aircraft(DisasterVehicle *v, uint16 image_override, bool leave_at_top, StringID news_message, IndustryBehaviour industry_flag)

{

	v->tick_counter++;

	GetNewVehiclePosResult gp = GetNewVehiclePos(v);

	v->UpdatePosition(gp.x, gp.y, GetAircraftFlightLevel(v));

		return false;

	}

		if (GB(v->tick_counter, 0, 2) == 0) {

			Industry *i = Industry::Get(v->dest_tile); // Industry destructor calls ReleaseDisastersTargetingIndustry, so this is valid

			int x = TileX(i->location.tile) * TILE_SIZE;

				GB(r, 12, 4),

				EV_EXPLOSION_SMALL);

		}

		if (++v->age == 112) {

			v->age = 0;

			Industry *i = Industry::Get(v->dest_tile); // Industry destructor calls ReleaseDisastersTargetingIndustry, so this is valid

			AddIndustryNewsItem(news_message, NT_ACCIDENT, i->index);

			if (_settings_client.sound.disaster) SndPlayTileFx(SND_12_EXPLOSION, i->location.tile);

		}

		int x = v->x_pos + ((leave_at_top ? -15 : 15) * TILE_SIZE);

		int y = v->y_pos;

		v->dest_tile = ind;

		if (GetIndustrySpec(Industry::Get(ind)->type)->behaviour & industry_flag) {

			v->age = 0;

		}

	}

}

/**

 * 0: Fly around to the middle of the map, then randomly for a while and home in on a piece of rail

 * 1: Land there and breakdown all trains in a radius of 12 tiles; and now we wait...

 *    because as soon as the Ufo lands, a fighter jet, a Skyranger, is called to clear up the mess

{

	v->tick_counter++;

		int x = TileX(v->dest_tile) * TILE_SIZE + TILE_SIZE / 2;

		int y = TileY(v->dest_tile) * TILE_SIZE + TILE_SIZE / 2;

		if (Delta(v->x_pos, x) + Delta(v->y_pos, y) >= 8) {

			return true;

		}

		for (Vehicle *target : Vehicle::Iterate()) {

			if (target->IsGroundVehicle()) {

		DisasterVehicle *u = new DisasterVehicle(-6 * (int)TILE_SIZE, v->y_pos, DIR_SW, ST_BIG_UFO_DESTROYER, v->index);

		DisasterVehicle *w = new DisasterVehicle(-6 * (int)TILE_SIZE, v->y_pos, DIR_SW, ST_BIG_UFO_DESTROYER_SHADOW);

		u->SetNext(w);

		int x = TileX(v->dest_tile) * TILE_SIZE;

		int y = TileY(v->dest_tile) * TILE_SIZE;

		if (Delta(x, v->x_pos) + Delta(y, v->y_pos) >= (int)TILE_SIZE) {

			v->dest_tile = RandomTile();

			return true;

		}

		const auto is_valid_target = [](const Train *t) {

			return t->IsFrontEngine() // Only the engines

}

/**

 * 0: Home in on landed Ufo and shoot it down

 */

static bool DisasterTick_Big_Ufo_Destroyer(DisasterVehicle *v)

		return false;

	}

		Vehicle *u = Vehicle::Get(v->big_ufo_destroyer_target);

		if (Delta(v->x_pos, u->x_pos) > (int)TILE_SIZE) return true;

		CreateEffectVehicleRel(u, 0, 7, 8, EV_EXPLOSION_LARGE);

		if (_settings_client.sound.disaster) SndPlayVehicleFx(SND_12_EXPLOSION, u);

}

/**

 * Unused, just float around aimlessly and pop up at different places, turning around

 */

static bool DisasterTick_Submarine(DisasterVehicle *v)

		/* primary disaster vehicles that have chosen target */

		if (v->subtype == ST_AIRPLANE || v->subtype == ST_HELICOPTER) {

			/* if it has chosen target, and it is this industry (yes, dest_tile is IndustryID here), set order to "leaving map peacefully" */

		}

	}

}

	for (DisasterVehicle *v : DisasterVehicle::Iterate()) {

		/* primary disaster vehicles that have chosen target */

		if (v->subtype == ST_SMALL_UFO) {

				/* Revert to target-searching */

				v->dest_tile = RandomTile();

				GetAircraftFlightLevelBounds(v, &v->z_pos, nullptr);

				v->age = 0;

	SpriteID image_override;            ///< Override for the default disaster vehicle sprite.

	VehicleID big_ufo_destroyer_target; ///< The big UFO that this destroyer is supposed to bomb.

	byte flags;                         ///< Flags about the state of the vehicle, @see AirVehicleFlags

	/** For use by saveload. */

	DisasterVehicle() : SpecializedVehicleBase() {}

	if (IsSavegameVersionBefore(SLV_121)) {

		/* Delete small ufos heading for non-existing vehicles */

				const Vehicle *u = Vehicle::GetIfValid(v->dest_tile);

				if (u == nullptr || u->type != VEH_ROAD || !RoadVehicle::From(u)->IsFrontEngine()) {

					delete v;

		}

		v->current_order.AssignOrder(UnpackOldOrder(_old_order));

		v->next = (Vehicle *)(size_t)_old_next_ptr;

		if (_cargo_count != 0 && CargoPacket::CanAllocateItem()) {

	SLV_EXTEND_VEHICLE_RANDOM,              ///< 310  PR#10701 Extend vehicle random bits.

	SLV_EXTEND_ENTITY_MAPPING,              ///< 311  PR#10672 Extend entity mapping range.

	SL_MAX_VERSION,                         ///< Highest possible saveload version

};

		    SLE_VAR(Vehicle, owner,                 SLE_UINT8),

		    SLE_VAR(Vehicle, vehstatus,             SLE_UINT8),

		    SLE_VAR(Vehicle, sprite_cache.sprite_seq.seq[0].sprite, SLE_FILE_U16 | SLE_VAR_U32),

		SLE_CONDVAR(Vehicle, age,                   SLE_FILE_U16 | SLE_VAR_I32,   SL_MIN_VERSION,  SLV_31),