Function GetTurnDirectionBasic

libs/routing/car_directions.cpp:434–530

}

void GetTurnDirectionBasic(IRoutingResult const & result, size_t const outgoingSegmentIndex,
                           NumMwmIds const & numMwmIds, RoutingSettings const & vehicleSettings, TurnItem & turn)
{
  TurnInfo turnInfo;
  if (!GetTurnInfo(result, outgoingSegmentIndex, vehicleSettings, turnInfo))
    return;

  turn.m_turn = CarDirection::None;

  ASSERT_GREATER(turnInfo.m_ingoing->m_path.size(), 1, ());
  TurnCandidates nodes;
  size_t ingoingCount;
  m2::PointD const junctionPoint = turnInfo.m_ingoing->m_path.back().GetPoint();
  result.GetPossibleTurns(turnInfo.m_ingoing->m_segmentRange, junctionPoint, ingoingCount, nodes);
  if (nodes.isCandidatesAngleValid)
  {
    ASSERT(is_sorted(nodes.candidates.begin(), nodes.candidates.end(), base::LessBy(&TurnCandidate::m_angle)),
           ("Turn candidates should be sorted by its angle field."));
  }

  /// @todo Proper handling of isCandidatesAngleValid == False, when we don't have angles of candidates.

  if (nodes.candidates.size() == 0)
    return;

  // No turns are needed on transported road.
  if (turnInfo.m_ingoing->m_highwayClass == HighwayClass::Transported &&
      turnInfo.m_outgoing->m_highwayClass == HighwayClass::Transported)
    return;

  Segment firstOutgoingSeg;
  if (!turnInfo.m_outgoing->m_segmentRange.GetFirstSegment(numMwmIds, firstOutgoingSeg))
    return;

  CorrectCandidatesSegmentByOutgoing(turnInfo, firstOutgoingSeg, nodes);

  RemoveUTurnCandidate(turnInfo, numMwmIds, nodes.candidates);
  auto const & turnCandidates = nodes.candidates;

  // Check for enter or exit to/from roundabout.
  if (turnInfo.m_ingoing->m_onRoundabout || turnInfo.m_outgoing->m_onRoundabout)
  {
    turn.m_turn = GetRoundaboutDirection(turnInfo, nodes, numMwmIds);
    // If there is 1 or more exits (nodes.candidates > 1) right at the enter it should be counted. Issue #3027.
    if (turn.m_turn == CarDirection::EnterRoundAbout && nodes.candidates.size() > 1)
      turn.m_exitNum = 1;
    return;
  }

  double const turnAngle = CalcTurnAngle(result, outgoingSegmentIndex, numMwmIds, vehicleSettings);

  CarDirection const intermediateDirection = IntermediateDirection(turnAngle);

  // Checking for exits from highways.
  turn.m_turn = TryToGetExitDirection(nodes, turnInfo, firstOutgoingSeg, intermediateDirection);
  if (turn.m_turn != CarDirection::None)
    return;