Method GetTurnDirection

libs/routing/car_directions.cpp:109–141

                           NumMwmIds const & numMwmIds, RoutingSettings const & vehicleSettings, TurnItem & turn);

size_t CarDirectionsEngine::GetTurnDirection(IRoutingResult const & result, size_t const outgoingSegmentIndex,
                                             NumMwmIds const & numMwmIds, RoutingSettings const & vehicleSettings,
                                             TurnItem & turnItem)
{
  if (outgoingSegmentIndex == result.GetSegments().size())
  {
    turnItem.m_turn = CarDirection::ReachedYourDestination;
    return 0;
  }

  // This is for jump from initial point to start of the route. No direction is given.
  /// @todo Sometimes results of GetPossibleTurns are empty, sometimes are invalid.
  /// The best will be to fix GetPossibleTurns(). It will allow us to use following approach.
  /// E.g. Google Maps until you reach the destination will guide you to go to the left or to the right of the first
  /// road.
  if (outgoingSegmentIndex == 2)  // The same as turnItem.m_index == 2.
    return 0;

  size_t skipTurnSegments = CheckUTurnOnRoute(result, outgoingSegmentIndex, numMwmIds, vehicleSettings, turnItem);

  if (turnItem.m_turn == CarDirection::None)
    GetTurnDirectionBasic(result, outgoingSegmentIndex, numMwmIds, vehicleSettings, turnItem);

  // Lane information.
  if (turnItem.m_turn != CarDirection::None)
  {
    auto const & loadedSegments = result.GetSegments();
    auto const & ingoingSegment = loadedSegments[outgoingSegmentIndex - 1];
    turnItem.m_lanes = ingoingSegment.m_lanes;
  }

  return skipTurnSegments;
}

/*!
 * \brief Calculates a turn instruction if the ingoing edge or (and) the outgoing edge belongs to a