Method ClipLines

libs/transit/transit_graph_data.cpp:401–457

}

void GraphData::ClipLines(vector<m2::RegionD> const & borders)
{
  // Set with stop ids with stops which are inside |borders|.
  set<StopId> stopIdInside;
  for (auto const & stop : m_stops)
    if (m2::RegionsContain(borders, stop.GetPoint()))
      stopIdInside.insert(stop.GetId());

  set<StopId> hasNeighborInside;
  for (auto const & edge : m_edges)
  {
    auto const stop1Inside = stopIdInside.count(edge.GetStop1Id()) != 0;
    auto const stop2Inside = stopIdInside.count(edge.GetStop2Id()) != 0;
    if (stop1Inside && !stop2Inside)
      hasNeighborInside.insert(edge.GetStop2Id());
    if (stop2Inside && !stop1Inside)
      hasNeighborInside.insert(edge.GetStop1Id());
  }

  stopIdInside.insert(hasNeighborInside.cbegin(), hasNeighborInside.cend());

  // Filling |lines| with stops inside |borders|.
  vector<Line> lines;
  for (auto const & line : m_lines)
  {
    // Note. |stopIdsToFill| will be filled with continuous sequences of stop ids.
    // In most cases only one sequence of stop ids should be placed to |stopIdsToFill|.
    // But if a line is split by |borders| several times then several
    // continuous groups of stop ids will be placed to |stopIdsToFill|.
    // The loop below goes through all the stop ids belong the line |line| and
    // keeps in |stopIdsToFill| continuous groups of stop ids which are inside |borders|.
    Ranges stopIdsToFill;
    Ranges const & ranges = line.GetStopIds();
    CHECK_EQUAL(ranges.size(), 1, ());
    vector<StopId> const & stopIds = ranges[0];
    auto it = stopIds.begin();
    while (it != stopIds.end())
    {
      while (it != stopIds.end() && stopIdInside.count(*it) == 0)
        ++it;
      auto jt = it;
      while (jt != stopIds.end() && stopIdInside.count(*jt) != 0)
        ++jt;
      if (it != jt)
        stopIdsToFill.emplace_back(it, jt);
      it = jt;
    }

    if (!stopIdsToFill.empty())
    {
      lines.emplace_back(line.GetId(), line.GetNumber(), line.GetTitle(), line.GetType(), line.GetColor(),
                         line.GetNetworkId(), stopIdsToFill, line.GetInterval());
    }
  }

  m_lines.swap(lines);
}