/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

 /*

  * Copyright (c) 2008 INESC Porto

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License version 2 as

  * published by the Free Software Foundation;

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program; if not, write to the Free Software

  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  *

  * Author: Gustavo Carneiro  <gjc@inescporto.pt>

  */

 #include <stdlib.h>

 #include "pyviz.h"

 #include "ns3/simulator.h"

 #include "ns3/config.h"

 #include "ns3/node-list.h"

 #include "ns3/wifi-net-device.h"

 #include "ns3/ethernet-header.h"

 #include "ns3/log.h"

 #include "ns3/ppp-header.h"

 #include <sstream>

 NS_LOG_COMPONENT_DEFINE ("PyViz");

 #define NUM_LAST_PACKETS 10

 static

 std::vector<std::string>

 PathSplit (std::string str)

 {

   std::vector<std::string> results;

   size_t cutAt;

   while ((cutAt = str.find_first_of('/')) != str.npos)

     {

       if(cutAt > 0)

         {

           results.push_back(str.substr(0,cutAt));

         }

       str = str.substr(cutAt+1);

     }

   if (str.length() > 0)

     {

       results.push_back(str);

     }

   return results;

 }

 namespace ns3 {

 static PyViz* g_visualizer = NULL;

 PyViz::PyViz ()

 {

   NS_ASSERT (g_visualizer == NULL);

   g_visualizer = this;

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::WifiNetDevice/Tx",

                    MakeCallback (&PyViz::TraceNetDevTxWifi, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::WifiNetDevice/Rx",

                    MakeCallback (&PyViz::TraceNetDevRxWifi, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::CsmaNetDevice/TxQueue/Dequeue",

                    MakeCallback (&PyViz::TraceNetDevTxCsma, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::CsmaNetDevice/Rx",

                    MakeCallback (&PyViz::TraceNetDevRxCsma, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::CsmaNetDevice/PromiscRx",

                    MakeCallback (&PyViz::TraceNetDevPromiscRxCsma, this));

   Config::Connect ("/NodeList/*/DeviceList/*/TxQueue/Drop",

                    MakeCallback (&PyViz::TraceDrop, this));

   Config::Connect ("/NodeList/*/$ns3::Ipv4L3Protocol/Drop",

                    MakeCallback (&PyViz::TraceDrop, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::PointToPointNetDevice/TxQueue/Dequeue",

                    MakeCallback (&PyViz::TraceNetDevTxPointToPoint, this));

   Config::Connect ("/NodeList/*/DeviceList/*/$ns3::PointToPointNetDevice/Rx",

                    MakeCallback (&PyViz::TraceNetDevRxPointToPoint, this));

 }

 void

 PyViz::RegisterCsmaLikeDevice (std::string const &deviceTypeName)

 {

   TypeId::LookupByName (deviceTypeName); // this will assert if the type name is invalid

   std::ostringstream sstream;

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/TxQueue/Dequeue";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevTxCsma, this));

   sstream.str ("");

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/Rx";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevRxCsma, this));

   sstream.str ("");

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/PromiscRx";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevPromiscRxCsma, this));

 }

 void

 PyViz::RegisterWifiLikeDevice (std::string const &deviceTypeName)

 {

   TypeId::LookupByName (deviceTypeName); // this will assert if the type name is invalid

   std::ostringstream sstream;

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/Tx";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevTxWifi, this));

   sstream.str ("");

   sstream <<"/NodeList/*/DeviceList/*/$" << deviceTypeName << "/Rx";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevRxWifi, this));

 }

 void

 PyViz::RegisterPointToPointLikeDevice (std::string const &deviceTypeName)

 {

   TypeId::LookupByName (deviceTypeName); // this will assert if the type name is invalid

   std::ostringstream sstream;

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/TxQueue/Dequeue";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevTxPointToPoint, this));

   sstream.str ("");

   sstream << "/NodeList/*/DeviceList/*/$" << deviceTypeName << "/Rx";

   Config::Connect (sstream.str (), MakeCallback (&PyViz::TraceNetDevRxPointToPoint, this));

 }

 void

 PyViz::SetPacketCaptureOptions (uint32_t nodeId, PacketCaptureOptions options)

 {

   NS_LOG_DEBUG ("  SetPacketCaptureOptions " << nodeId

                 << " PacketCaptureOptions (headers size = " << options.headers.size ()

                 << " mode = " << options.mode << " numLastPackets = " << options.numLastPackets

                 << ")");

   m_packetCaptureOptions[nodeId] = options;

 }

 void

 PyViz::RegisterDropTracePath (std::string const &tracePath)

 {

   Config::Connect (tracePath, MakeCallback (&PyViz::TraceDrop, this));

 }

 PyViz::~PyViz ()

 {

   NS_ASSERT (g_visualizer == this);

   g_visualizer = NULL;

 }

 void PyViz::DoPause (std::string const &message)

 {

   m_pauseMessages.push_back (message);

   m_stop = true;

   NS_LOG_LOGIC (Simulator::Now ().GetSeconds () << ": Have "

                 << g_visualizer->m_pauseMessages.size () << " pause messages");

 }

 void PyViz::Pause (std::string const &message)

 {

   NS_ASSERT (g_visualizer);

   g_visualizer->DoPause (message);

 }

 std::vector<std::string>

 PyViz::GetPauseMessages () const

 {

   NS_LOG_LOGIC (Simulator::Now ().GetSeconds () << ": GetPauseMessages: have "

                 << g_visualizer->m_pauseMessages.size () << " pause messages");

   return m_pauseMessages;

 }

 void

 PyViz::CallbackStopSimulation ()

 {

   NS_LOG_FUNCTION_NOARGS ();

   m_stop = true;

 }

 void

 PyViz::SimulatorRunUntil (Time time)

 {

   NS_LOG_LOGIC ("SimulatorRunUntil " << time << " (now is " << Simulator::Now () << ")");

   m_pauseMessages.clear ();

   m_transmissionSamples.clear ();

   m_packetDrops.clear ();

   Time expirationTime = Simulator::Now () - Seconds (10);

   // Clear very old transmission records

   for (std::map<TxRecordKey, TxRecordValue>::iterator iter = m_txRecords.begin ();

        iter != m_txRecords.end ();)

     {

       if (iter->second.time < expirationTime)

         {

           m_txRecords.erase (iter++);

         }

       else

         {

           iter++;

         }

     }

   // Clear very old packets of interest

   for (std::map<uint32_t, Time>::iterator iter = m_packetsOfInterest.begin ();

        iter != m_packetsOfInterest.end ();)

     {

       if (iter->second < expirationTime)

         {

           m_packetsOfInterest.erase (iter++);

         }

       else

         {

           iter++;

         }

     }

   if (Simulator::IsFinished () || Simulator::Now () >= time)

     {

       return;

     }

   // Schedule a dummy callback function for the target time, to make

   // sure we stop at the right time.  Otherwise, simulations with few

   // events just appear to "jump" big chunks of time.

   NS_LOG_LOGIC ("Schedule dummy callback to be called in " << (time - Simulator::Now ()));

   m_stop = false;

   Simulator::Cancel (m_stopCallbackEvent);

   m_stopCallbackEvent = Simulator::Schedule (time - Simulator::Now (), &PyViz::CallbackStopSimulation, this);

   while (!Simulator::IsFinished ())

     {

       if (m_stop)

         {

           break;

         }

       Simulator::RunOneEvent ();

     }

 }

 bool PyViz::TransmissionSampleKey::operator < (PyViz::TransmissionSampleKey const &other) const

 {

   if (this->transmitter < other.transmitter)

     {

       return true;

     }

   if (this->transmitter != other.transmitter)

     {

       return false;

     }

   if (this->receiver < other.receiver)

     {

       return true;}

   if (this->receiver != other.receiver)

     {

       return false;

     }

   if (this->channel < other.channel)

     {

       return true;

     }

   else

     {

       return false;

     }

 }

 bool PyViz::TransmissionSampleKey::operator == (PyViz::TransmissionSampleKey const &other) const

 {

   bool retval = (transmitter == other.transmitter) &&

     (receiver == other.receiver) &&

     (channel == other.channel);

   return retval;

 }

 PyViz::NetDeviceStatistics &

 PyViz::FindNetDeviceStatistics (int node, int interface)

 {

   std::map<uint32_t, std::vector<NetDeviceStatistics> >::iterator nodeStatsIter = m_nodesStatistics.find (node);

   std::vector<NetDeviceStatistics> *stats;

   if (nodeStatsIter == m_nodesStatistics.end ())

     {

       stats = &m_nodesStatistics[node];

       stats->resize (NodeList::GetNode (node)->GetNDevices ());

     }

   else

     {

       stats = &(nodeStatsIter->second);

     }

   NetDeviceStatistics &devStats = (*stats)[interface];

   return devStats;

 }

 bool PyViz::GetPacketCaptureOptions (uint32_t nodeId, const PacketCaptureOptions **outOptions) const

 {

   std::map<uint32_t, PacketCaptureOptions>::const_iterator iter = m_packetCaptureOptions.find (nodeId);

   if (iter == m_packetCaptureOptions.end ())

     {

       return false;

     }

   else

     {

       *outOptions = &iter->second;

       return true;

     }

 }

 bool PyViz::FilterPacket (Ptr<const Packet> packet, const PacketCaptureOptions &options)

 {

   switch (options.mode)

     {

     case PACKET_CAPTURE_DISABLED:

       return false;

     case PACKET_CAPTURE_FILTER_HEADERS_OR:

       {

         PacketMetadata::ItemIterator metadataIterator = packet->BeginItem ();

         while (metadataIterator.HasNext ())

           {

             PacketMetadata::Item item = metadataIterator.Next ();

             if (options.headers.find (item.tid) != options.headers.end ())

               {

                 return true;

               }

           }

         return false;

       }

     case PACKET_CAPTURE_FILTER_HEADERS_AND:

       {

         std::set<TypeId> missingHeaders (options.headers);

         PacketMetadata::ItemIterator metadataIterator = packet->BeginItem ();

         while (metadataIterator.HasNext ())

           {

             PacketMetadata::Item item = metadataIterator.Next ();

             std::set<TypeId>::iterator missingIter = missingHeaders.find (item.tid);

             if (missingIter != missingHeaders.end ())

               {

                 missingHeaders.erase (missingIter);

               }

           }

         if (missingHeaders.size () == 0)

           {

             return true;

           }

         else

           {

             return false;

           }

       }

     default:

       NS_FATAL_ERROR ("should not be reached");

       return false;

     }

 }

 void PyViz::TraceDrop (std::string context, Ptr<const Packet> packet)

 {

   NS_LOG_FUNCTION (context << packet->GetUid ());

   std::vector<std::string> splitPath = PathSplit (context);

   int nodeIndex = atoi (splitPath[1].c_str ());

   Ptr<Node> node = NodeList::GetNode (nodeIndex);

   if (m_nodesOfInterest.find (nodeIndex) == m_nodesOfInterest.end ())

     {

       // if the transmitting node is not "of interest", we still

       // record the transmission if it is a packet of interest.

       if (m_packetsOfInterest.find (packet->GetUid ()) == m_packetsOfInterest.end ())

         {

           NS_LOG_DEBUG ("Packet " << packet->GetUid () << " is not of interest");

           return;

         }

     }

   // ---- "last packets"

   const PacketCaptureOptions *captureOptions;

   if (GetPacketCaptureOptions (nodeIndex, &captureOptions) && FilterPacket (packet, *captureOptions))

     {

       LastPacketsSample &last = m_lastPackets[nodeIndex];

       PacketSample lastPacket;

       lastPacket.time = Simulator::Now ();

       lastPacket.packet = packet->Copy ();

       lastPacket.device = NULL;

       last.lastDroppedPackets.push_back (lastPacket);

       while (last.lastDroppedPackets.size () > captureOptions->numLastPackets)

         {

           last.lastDroppedPackets.erase (last.lastDroppedPackets.begin ());

         }

     }

   std::map<Ptr<Node>, uint32_t>::iterator iter = m_packetDrops.find (node);

   if (iter == m_packetDrops.end ())

     {

       m_packetDrops[node] = packet->GetSize ();

     }

   else

     {

       iter->second += packet->GetSize ();

     }

 }

 void

 PyViz::TraceNetDevTxWifi (std::string context, Ptr<const Packet> packet, Mac48Address destinationAddress)

 {

   NS_LOG_FUNCTION (context << packet->GetUid () << *packet);

   std::vector<std::string> splitPath = PathSplit (context);

   int nodeIndex = atoi (splitPath[1].c_str ());

   int devIndex = atoi (splitPath[3].c_str ());

   Ptr<Node> node = NodeList::GetNode (nodeIndex);

   Ptr<NetDevice> device = node->GetDevice (devIndex);

   // ---- statistics

   NetDeviceStatistics &stats = FindNetDeviceStatistics (nodeIndex, devIndex);

   ++stats.transmittedPackets;

   stats.transmittedBytes += packet->GetSize ();

   // ---- "last packets"

   const PacketCaptureOptions *captureOptions;

   if (GetPacketCaptureOptions (nodeIndex, &captureOptions) && FilterPacket (packet, *captureOptions))

     {

       LastPacketsSample &last = m_lastPackets[nodeIndex];

       TxPacketSample lastPacket;

       lastPacket.time = Simulator::Now ();

       lastPacket.packet = packet->Copy ();

       lastPacket.device = device;

       lastPacket.to = destinationAddress;

       last.lastTransmittedPackets.push_back (lastPacket);

       while (last.lastTransmittedPackets.size () > captureOptions->numLastPackets)

         {

           last.lastTransmittedPackets.erase (last.lastTransmittedPackets.begin ());

         }

     }

   // ---- transmissions records

   if (m_nodesOfInterest.find (nodeIndex) == m_nodesOfInterest.end ())

     {

       // if the transmitting node is not "of interest", we still

       // record the transmission if it is a packet of interest.

       if (m_packetsOfInterest.find (packet->GetUid ()) == m_packetsOfInterest.end ())

         {

           NS_LOG_DEBUG ("Packet " << packet->GetUid () << " is not of interest");

           return;

         }

     }

   else

     {

       // We will follow this packet throughout the network.

       m_packetsOfInterest[packet->GetUid ()] = Simulator::Now ();

     }

   TxRecordValue record = { Simulator::Now (), node, false };

   if (destinationAddress == device->GetBroadcast ())

     {

       record.isBroadcast = true;

     }

   m_txRecords[TxRecordKey (device->GetChannel (), packet->GetUid ())] = record;

 }

 void

 PyViz::TraceNetDevRxCsma (std::string context, Ptr<const Packet> packet)

 {

   Ptr<Packet> p = packet->Copy ();

   EthernetHeader ethernetHeader;

   p->RemoveHeader (ethernetHeader);

   TraceNetDevRxWifi (context, p, ethernetHeader.GetSource ());

 }

 void

 PyViz::TraceNetDevRxPointToPoint (std::string context, Ptr<const Packet> packet)

 {

   Ptr<Packet> p = packet->Copy ();

   PppHeader h;

   p->RemoveHeader (h);

   TraceNetDevRxWifi (context, p, Mac48Address ());

 }

 void

 PyViz::TraceNetDevPromiscRxCsma (std::string context, Ptr<const Packet> packet, NetDevice::PacketType packetType)

 {

   Ptr<Packet> p = packet->Copy ();

   EthernetHeader ethernetHeader;

   p->RemoveHeader (ethernetHeader);

   // Other packet types are already being received by

   // TraceNetDevRxCsma; we don't want to receive them twice.

   if (packetType == NetDevice::PACKET_OTHERHOST)

     {

       TraceNetDevRxWifi (context, p, ethernetHeader.GetDestination ());

     }

 }

 void

 PyViz::TraceNetDevTxCsma (std::string context, Ptr<const Packet> packet)

 {

   EthernetHeader ethernetHeader;

   Ptr<Packet> p = packet->Copy ();

   p->RemoveHeader (ethernetHeader);

   TraceNetDevTxWifi (context, p, ethernetHeader.GetDestination ());

 }

 void

 PyViz::TraceNetDevTxPointToPoint (std::string context, Ptr<const Packet> packet)

 {

   Ptr<Packet> p = packet->Copy ();

   PppHeader h;

   p->RemoveHeader (h);

   TraceNetDevTxWifi (context, p, Mac48Address ());

 }

 void

 PyViz::TraceNetDevRxWifi (std::string context, Ptr<const Packet> packet, Mac48Address from)

 {

   NS_LOG_FUNCTION (context << packet->GetUid ());

   std::vector<std::string> splitPath = PathSplit (context);

   int nodeIndex = atoi (splitPath[1].c_str ());

   int devIndex = atoi (splitPath[3].c_str ());

   // ---- statistics

   NetDeviceStatistics &stats = FindNetDeviceStatistics (nodeIndex, devIndex);

   ++stats.receivedPackets;

   stats.receivedBytes += packet->GetSize ();

   Ptr<Node> node = NodeList::GetNode (nodeIndex);

   Ptr<NetDevice> device = node->GetDevice (devIndex);

   // ---- "last packets"

   const PacketCaptureOptions *captureOptions;

   if (GetPacketCaptureOptions (nodeIndex, &captureOptions) && FilterPacket (packet, *captureOptions))

     {

       LastPacketsSample &last = m_lastPackets[nodeIndex];

       RxPacketSample lastPacket;

       lastPacket.time = Simulator::Now ();

       lastPacket.packet = packet->Copy ();

       lastPacket.device = device;

       lastPacket.from = from;

       last.lastReceivedPackets.push_back (lastPacket);

       while (last.lastReceivedPackets.size () > captureOptions->numLastPackets)

         {

           last.lastReceivedPackets.erase (last.lastReceivedPackets.begin ());

         }

     }

   // ---- transmissions

   if (m_packetsOfInterest.find (packet->GetUid ()) == m_packetsOfInterest.end ())

     {

       NS_LOG_DEBUG ("RX Packet " << packet->GetUid () << " is not of interest");

       return;

     }

   Ptr<Channel> channel = device->GetChannel ();

   std::map<TxRecordKey, TxRecordValue>::iterator recordIter = 

     m_txRecords.find (TxRecordKey (channel, packet->GetUid ()));

   if (recordIter == m_txRecords.end ())

     {

       NS_LOG_DEBUG ("RX Packet " << packet->GetUid () << " was not transmitted?!");

       return;

     }

   TxRecordValue &record = recordIter->second;

   if (record.srcNode == node)

     {

       NS_LOG_WARN ("Node " << node->GetId () << " receiving back the same packet (UID=" << packet->GetUid ()

                    << ") it had previously transmitted, on the same channel!");

       return;

     }

   TransmissionSampleKey key = { record.srcNode, node, channel };

 #ifdef  NS3_LOG_ENABLE

   NS_LOG_DEBUG("m_transmissionSamples begin:");

   if (g_log.IsEnabled (ns3::LOG_DEBUG))

     {

       for (std::map<TransmissionSampleKey,TransmissionSampleValue>::const_iterator iter

              = m_transmissionSamples.begin (); iter != m_transmissionSamples.end (); iter++)

         {

           NS_LOG_DEBUG(iter->first.transmitter<<"/"<<iter->first.transmitter->GetId () << ", "

                        << iter->first.receiver<<"/"<<iter->first.receiver->GetId ()

                        << ", " << iter->first.channel << " => " << iter->second.bytes << " (@ " << &iter->second << ")");

         }

     }

   NS_LOG_DEBUG("m_transmissionSamples end.");

 #endif

   std::map<TransmissionSampleKey,TransmissionSampleValue>::iterator

     iter = m_transmissionSamples.find (key);

   if (iter == m_transmissionSamples.end ())

     {

       TransmissionSampleValue sample = { packet->GetSize () };

       NS_LOG_DEBUG ("RX: from " << key.transmitter<<"/"<<key.transmitter->GetId() << " to "

                     << key.receiver<<"/"<<key.receiver->GetId()

                     << " channel " << channel << ": " << packet->GetSize ()

                     << " bytes more. => new sample with " << packet->GetSize () << " bytes.");

       m_transmissionSamples[key] = sample;

     }

   else

     {

       TransmissionSampleValue &sample = iter->second;

       NS_LOG_DEBUG ("RX: from " << key.transmitter<<"/"<<key.transmitter->GetId() << " to "

                     << key.receiver<<"/"<<key.receiver->GetId()

                     << " channel " << channel << ": " << packet->GetSize ()

                     << " bytes more. => sample " << &sample << " with bytes " << sample.bytes);

       sample.bytes += packet->GetSize ();

     }

 }

 PyViz::TransmissionSampleList

 PyViz::GetTransmissionSamples () const

 {

   NS_LOG_DEBUG ("GetTransmissionSamples BEGIN");

   TransmissionSampleList list;

   for (std::map<TransmissionSampleKey, TransmissionSampleValue>::const_iterator

          iter = m_transmissionSamples.begin ();

        iter !=  m_transmissionSamples.end ();

        iter++)

     {

       TransmissionSample sample;

       sample.transmitter = iter->first.transmitter;

       sample.receiver = iter->first.receiver;

       sample.channel = iter->first.channel;

       sample.bytes = iter->second.bytes;

       NS_LOG_DEBUG ("from " << sample.transmitter->GetId() << " to " << sample.receiver->GetId()

                     << ": " << sample.bytes << " bytes.");

       list.push_back (sample);

     }

   NS_LOG_DEBUG ("GetTransmissionSamples END");

   return list;

 }

 PyViz::PacketDropSampleList

 PyViz::GetPacketDropSamples () const

 {

   NS_LOG_DEBUG ("GetPacketDropSamples BEGIN");

   PacketDropSampleList list;

   for (std::map<Ptr<Node>, uint32_t>::const_iterator

          iter = m_packetDrops.begin ();

        iter !=  m_packetDrops.end ();

        iter++)

     {

       PacketDropSample sample;

       sample.transmitter = iter->first;

       sample.bytes = iter->second;

       NS_LOG_DEBUG ("in " << sample.transmitter->GetId() 

                     << ": " << sample.bytes << " bytes dropped.");

       list.push_back (sample);

     }

   NS_LOG_DEBUG ("GetPacketDropSamples END");

   return list;

 }

 void

 PyViz::SetNodesOfInterest (std::set<uint32_t> nodes)

 {

   m_nodesOfInterest = nodes;

 }

 std::vector<PyViz::NodeStatistics>

 PyViz::GetNodesStatistics () const

 {

   std::vector<PyViz::NodeStatistics> retval;

   for (std::map<uint32_t, std::vector<NetDeviceStatistics> >::const_iterator iter = m_nodesStatistics.begin ();

        iter != m_nodesStatistics.end (); iter++)

     {

       NodeStatistics stats = { iter->first, iter->second };

       retval.push_back (stats);

     }

   return retval;

 }

 PyViz::LastPacketsSample

 PyViz::GetLastPackets (uint32_t nodeId) const

 {

   NS_LOG_DEBUG ("GetLastPackets: " << nodeId);

   std::map<uint32_t, LastPacketsSample>::const_iterator

     iter = m_lastPackets.find(nodeId);

   if (iter != m_lastPackets.end ())

     {

       return iter->second;

     }

   else

     {

       return LastPacketsSample ();

     }

 }

 namespace

 {

   // Adapted from http://en.wikipedia.org/w/index.php?title=Line_clipping&oldid=248609574

   class FastClipping

   {

   public:

     struct Vector2 

     {

       double x;

       double y;

     };

     Vector2 m_clipMin, m_clipMax;

     struct Line

     {

       Vector2 start, end;

       double dx, dy;

     };

   private:

     void ClipStartTop (Line &line)

     {

       line.start.x += line.dx * (m_clipMin.y - line.start.y) / line.dy;

       line.start.y = m_clipMin.y;

     }

     void ClipStartBottom (Line &line)

     {

       line.start.x += line.dx * (m_clipMax.y - line.start.y) / line.dy;

       line.start.y = m_clipMax.y;

     }

     void ClipStartRight (Line &line)

     {

       line.start.y += line.dy * (m_clipMax.x - line.start.x) / line.dx;

       line.start.x = m_clipMax.x;

     }

     void ClipStartLeft (Line &line)

     {

       line.start.y += line.dy * (m_clipMin.x - line.start.x) / line.dx;

       line.start.x = m_clipMin.x;

     }

     void ClipEndTop (Line &line)

     {

       line.end.x += line.dx * (m_clipMin.y - line.end.y) / line.dy;

       line.end.y = m_clipMin.y;

     }

     void ClipEndBottom (Line &line) {

       line.end.x += line.dx * (m_clipMax.y - line.end.y) / line.dy;

       line.end.y = m_clipMax.y;

     }

     void ClipEndRight (Line &line)

     {

       line.end.y += line.dy * (m_clipMax.x - line.end.x) / line.dx;

       line.end.x = m_clipMax.x;

     }

     void ClipEndLeft (Line &line)

     {

       line.end.y += line.dy * (m_clipMin.x - line.end.x) / line.dx;

       line.end.x = m_clipMin.x;

     }

   public:

     FastClipping (Vector2 clipMin, Vector2 clipMax)

       : m_clipMin (clipMin), m_clipMax (clipMax)

     {

     }

     bool ClipLine (Line &line)

     {

       uint8_t lineCode = 0;

       if (line.end.y < m_clipMin.y)

         lineCode |= 8;

       else if (line.end.y > m_clipMax.y)

         lineCode |= 4;

       if (line.end.x > m_clipMax.x)

         lineCode |= 2;

       else if (line.end.x < m_clipMin.x)

         lineCode |= 1;

       if (line.start.y < m_clipMin.y)

         lineCode |= 128;

       else if (line.start.y > m_clipMax.y)

         lineCode |= 64;

       if (line.start.x > m_clipMax.x)

         lineCode |= 32;

       else if (line.start.x < m_clipMin.x)

         lineCode |= 16;

       // 9 - 8 - A

       // |   |   |

       // 1 - 0 - 2

       // |   |   |

       // 5 - 4 - 6

       switch (lineCode)

         {

           // center

         case 0x00:

           return true;

         case 0x01:

           ClipEndLeft (line);

           return true;

         case 0x02:

           ClipEndRight (line);

           return true;

         case 0x04:

           ClipEndBottom (line);

           return true;

         case 0x05:

           ClipEndLeft (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

         case 0x06:

           ClipEndRight (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

         case 0x08:

           ClipEndTop (line);

           return true;

         case 0x09:

           ClipEndLeft (line);

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           return true;

         case 0x0A:

           ClipEndRight (line);

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           return true;

           // left

         case 0x10:

           ClipStartLeft (line);

           return true;

         case 0x12:

           ClipStartLeft (line);

           ClipEndRight (line);

           return true;

         case 0x14:

           ClipStartLeft (line);

           if (line.start.y > m_clipMax.y)

             return false;

           ClipEndBottom (line);

           return true;

         case 0x16:

           ClipStartLeft (line);

           if (line.start.y > m_clipMax.y)

             return false;

           ClipEndBottom (line);

           if (line.end.x > m_clipMax.x)

             ClipEndRight (line);

           return true;

         case 0x18:

           ClipStartLeft (line);

           if (line.start.y < m_clipMin.y)

             return false;

           ClipEndTop (line);

           return true;

         case 0x1A:

           ClipStartLeft (line);

           if (line.start.y < m_clipMin.y)

             return false;

           ClipEndTop (line);

           if (line.end.x > m_clipMax.x)

             ClipEndRight (line);

           return true;

           // right

         case 0x20:

           ClipStartRight (line);

           return true;

         case 0x21:

           ClipStartRight (line);

           ClipEndLeft (line);

           return true;

         case 0x24:

           ClipStartRight (line);

           if (line.start.y > m_clipMax.y)

             return false;

           ClipEndBottom (line);

           return true;

         case 0x25:

           ClipStartRight (line);

           if (line.start.y > m_clipMax.y)

             return false;

           ClipEndBottom (line);

           if (line.end.x < m_clipMin.x)

             ClipEndLeft (line);

           return true;

         case 0x28:

           ClipStartRight (line);

           if (line.start.y < m_clipMin.y)

             return false;

           ClipEndTop (line);

           return true;

         case 0x29:

           ClipStartRight (line);

           if (line.start.y < m_clipMin.y)

             return false;

           ClipEndTop (line);

           if (line.end.x < m_clipMin.x)

             ClipEndLeft (line);

           return true;

           // bottom

         case 0x40:

           ClipStartBottom (line);

           return true;

         case 0x41:

           ClipStartBottom (line);

           if (line.start.x < m_clipMin.x)

             return false;

           ClipEndLeft (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

         case 0x42:

           ClipStartBottom (line);

           if (line.start.x > m_clipMax.x)

             return false;

           ClipEndRight (line);

           return true;

         case 0x48:

           ClipStartBottom (line);

           ClipEndTop (line);

           return true;

         case 0x49:

           ClipStartBottom (line);

           if (line.start.x < m_clipMin.x)

             return false;

           ClipEndLeft (line);

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           return true;

         case 0x4A:

           ClipStartBottom (line);

           if (line.start.x > m_clipMax.x)

             return false;

           ClipEndRight (line);

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           return true;

           // bottom-left

         case 0x50:

           ClipStartLeft (line);

           if (line.start.y > m_clipMax.y)

             ClipStartBottom (line);

           return true;

         case 0x52:

           ClipEndRight (line);

           if (line.end.y > m_clipMax.y)

             return false;

           ClipStartBottom (line);

           if (line.start.x < m_clipMin.x)

             ClipStartLeft (line);

           return true;

         case 0x58:

           ClipEndTop (line);

           if (line.end.x < m_clipMin.x)

             return false;

           ClipStartBottom (line);

           if (line.start.x < m_clipMin.x)

             ClipStartLeft (line);

           return true;

         case 0x5A:

           ClipStartLeft (line);

           if (line.start.y < m_clipMin.y)

             return false;

           ClipEndRight (line);

           if (line.end.y > m_clipMax.y)

             return false;

           if (line.start.y > m_clipMax.y)

             ClipStartBottom (line);

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           return true;

           // bottom-right

         case 0x60:

           ClipStartRight (line);

           if (line.start.y > m_clipMax.y)

             ClipStartBottom (line);

           return true;

         case 0x61:

           ClipEndLeft (line);

           if (line.end.y > m_clipMax.y)

             return false;

           ClipStartBottom (line);

           if (line.start.x > m_clipMax.x)

             ClipStartRight (line);

           return true;

         case 0x68:

           ClipEndTop (line);

           if (line.end.x > m_clipMax.x)

             return false;

           ClipStartRight (line);

           if (line.start.y > m_clipMax.y)

             ClipStartBottom (line);

           return true;

         case 0x69:

           ClipEndLeft (line);

           if (line.end.y > m_clipMax.y)

             return false;

           ClipStartRight (line);

           if (line.start.y < m_clipMin.y)

             return false;

           if (line.end.y < m_clipMin.y)

             ClipEndTop (line);

           if (line.start.y > m_clipMax.y)

             ClipStartBottom (line);

           return true;

           // top

         case 0x80:

           ClipStartTop (line);

           return true;

         case 0x81:

           ClipStartTop (line);

           if (line.start.x < m_clipMin.x)

             return false;

           ClipEndLeft (line);

           return true;

         case 0x82:

           ClipStartTop (line);

           if (line.start.x > m_clipMax.x)

             return false;

           ClipEndRight (line);

           return true;

         case 0x84:

           ClipStartTop (line);

           ClipEndBottom (line);

           return true;

         case 0x85:

           ClipStartTop (line);

           if (line.start.x < m_clipMin.x)

             return false;

           ClipEndLeft (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

         case 0x86:

           ClipStartTop (line);

           if (line.start.x > m_clipMax.x)

             return false;

           ClipEndRight (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

           // top-left

         case 0x90:

           ClipStartLeft (line);

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           return true;

         case 0x92:

           ClipEndRight (line);

           if (line.end.y < m_clipMin.y)

             return false;

           ClipStartTop (line);

           if (line.start.x < m_clipMin.x)

             ClipStartLeft (line);

           return true;

         case 0x94:

           ClipEndBottom (line);

           if (line.end.x < m_clipMin.x)

             return false;

           ClipStartLeft (line);

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           return true;

         case 0x96:

           ClipStartLeft (line);

           if (line.start.y > m_clipMax.y)

             return false;

           ClipEndRight (line);

           if (line.end.y < m_clipMin.y)

             return false;

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           return true;

           // top-right

         case 0xA0:

           ClipStartRight (line);

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           return true;

         case 0xA1:

           ClipEndLeft (line);

           if (line.end.y < m_clipMin.y)

             return false;

           ClipStartTop (line);

           if (line.start.x > m_clipMax.x)

             ClipStartRight (line);

           return true;

         case 0xA4:

           ClipEndBottom (line);

           if (line.end.x > m_clipMax.x)

             return false;

           ClipStartRight (line);

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           return true;

         case 0xA5:

           ClipEndLeft (line);

           if (line.end.y < m_clipMin.y)

             return false;

           ClipStartRight (line);

           if (line.start.y > m_clipMax.y)

             return false;

           if (line.end.y > m_clipMax.y)

             ClipEndBottom (line);

           if (line.start.y < m_clipMin.y)

             ClipStartTop (line);

           return true;

         }

       return false;

     }

   };

 }

 void

 PyViz::LineClipping (double boundsX1, double boundsY1, double boundsX2, double boundsY2,

                      double &lineX1, double &lineY1, double &lineX2, double &lineY2)

 {

   FastClipping::Vector2 clipMin = {boundsX1, boundsY1}, clipMax = {boundsX2, boundsY2};

   FastClipping::Line line = { { lineX1, lineY1 }, { lineX2, lineY2 }, (lineX2-lineX1), (lineY2-lineY1) };

   FastClipping clipper (clipMin, clipMax);

   clipper.ClipLine (line);

   lineX1 = line.start.x;

   lineX2 = line.end.x;

   lineY1 = line.start.y;

   lineY2 = line.end.y;

 }

 }