Function CmdStartStopVehicle

src/vehicle_cmd.cpp:575–655

* Start/Stop a vehicle * @param flags type of operation * @param veh_id vehicle to start/stop, don't forget to change CcStartStopVehicle if you modify this! * @param evaluate_startstop_cb Shall the start/stop newgrf callback be evaluated (only valid with DoCommandFlag::AutoReplace for network safety) * @return the cost of this operation or an error */

 * @return the cost of this operation or an error
 */
CommandCost CmdStartStopVehicle(DoCommandFlags flags, VehicleID veh_id, bool evaluate_startstop_cb)
{
	/* Disable the effect of evaluate_startstop_cb, when DoCommandFlag::AutoReplace is not set */
	if (!flags.Test(DoCommandFlag::AutoReplace)) evaluate_startstop_cb = true;

	Vehicle *v = Vehicle::GetIfValid(veh_id);
	if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;

	CommandCost ret = CheckOwnership(v->owner);
	if (ret.Failed()) return ret;

	if (v->vehstatus.Test(VehState::Crashed)) return CommandCost(STR_ERROR_VEHICLE_IS_DESTROYED);

	switch (v->type) {
		case VEH_TRAIN:
			if (v->vehstatus.Test(VehState::Stopped) && Train::From(v)->gcache.cached_power == 0) return CommandCost(STR_ERROR_TRAIN_START_NO_POWER);
			break;

		case VEH_SHIP:
		case VEH_ROAD:
			break;

		case VEH_AIRCRAFT: {
			Aircraft *a = Aircraft::From(v);
			/* cannot stop airplane when in flight, or when taking off / landing */
			if (a->state >= STARTTAKEOFF && a->state < TERM7) return CommandCost(STR_ERROR_AIRCRAFT_IS_IN_FLIGHT);
			if (HasBit(a->flags, VAF_HELI_DIRECT_DESCENT)) return CommandCost(STR_ERROR_AIRCRAFT_IS_IN_FLIGHT);
			break;
		}

		default: return CMD_ERROR;
	}

	if (evaluate_startstop_cb) {
		/* Check if this vehicle can be started/stopped. Failure means 'allow'. */
		std::array<int32_t, 1> regs100;
		uint16_t callback = GetVehicleCallback(CBID_VEHICLE_START_STOP_CHECK, 0, 0, v->engine_type, v, regs100);
		StringID error = STR_NULL;
		if (callback != CALLBACK_FAILED) {
			if (v->GetGRF()->grf_version < 8) {
				/* 8 bit result 0xFF means 'allow' */
				if (callback < 0x400 && GB(callback, 0, 8) != 0xFF) error = GetGRFStringID(v->GetGRFID(), GRFSTR_MISC_GRF_TEXT + callback);
			} else {
				if (callback < 0x400) {
					error = GetGRFStringID(v->GetGRFID(), GRFSTR_MISC_GRF_TEXT + callback);
				} else {
					switch (callback) {
						case 0x400: // allow
							break;

						case 0x40F:
							error = GetGRFStringID(v->GetGRFID(), static_cast<GRFStringID>(regs100[0]));
							break;

						default: // unknown reason -> disallow
							error = STR_ERROR_INCOMPATIBLE_RAIL_TYPES;
							break;
					}