natnet2ivy.c

/*
 * Copyright (C) 2014 Freek van Tienen
 *
 * This file is part of Paparazzi.
 *
 * Paparazzi is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * Paparazzi 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 Paparazzi; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

 /** \file natnet2ivy.c
 *  \brief NatNet (GPS) to ivy forwarder
 *
 *   This receives aircraft position information through the Optitrack system
 * NatNet UDP stream and forwards it to the ivy bus. An aircraft with the gps
 * subsystem "datalink" is then able to parse the GPS position and use it to
 * navigate inside the Optitrack system.
 */

#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <Ivy/ivy.h>
#include <Ivy/ivyglibloop.h>
#include <time.h>

#include "std.h"
#include "fms/fms_network.h"
#include "math/pprz_geodetic_double.h"
#include "math/pprz_algebra_double.h"

/** Debugging options */
uint8_t verbose = 0;
#define printf_natnet   if(verbose > 1) printf
#define printf_debug    if(verbose > 0) printf

/** NatNet defaults */
char *natnet_addr               = "255.255.255.255";
char *natnet_multicast_addr     = "239.255.42.99";
uint16_t natnet_cmd_port        = 1510;
uint16_t natnet_data_port       = 1511;
uint8_t natnet_major            = 2;
uint8_t natnet_minor            = 5;

/** Ivy Bus default */
#ifdef __APPLE__
char *ivy_bus                   = "224.255.255.255";
#else
char *ivy_bus                   = "127.255.255.255:2010";
#endif

/** Sample frequency and derevitive defaults */
uint32_t freq_transmit          = 30;     ///< Transmitting frequency in Hz
uint16_t min_velocity_samples   = 4;      ///< The amount of position samples needed for a valid velocity

/** Connection timeout when not receiving **/
#define CONNECTION_TIMEOUT          .5

/** NatNet parsing defines */
#define MAX_PACKETSIZE    100000
#define MAX_NAMELENGTH    256
#define MAX_RIGIDBODIES   128

#define NAT_PING                    0
#define NAT_PINGRESPONSE            1
#define NAT_REQUEST                 2
#define NAT_RESPONSE                3
#define NAT_REQUEST_MODELDEF        4
#define NAT_MODELDEF                5
#define NAT_REQUEST_FRAMEOFDATA     6
#define NAT_FRAMEOFDATA             7
#define NAT_MESSAGESTRING           8
#define NAT_UNRECOGNIZED_REQUEST    100
#define UNDEFINED                   999999.9999

/** Tracked rigid bodies */
struct RigidBody {
  int id;                           ///< Rigid body ID from the tracking system
  float x, y, z;                    ///< Rigid body x, y and z coordinates in meters (note y and z are swapped)
  float qx, qy, qz, qw;             ///< Rigid body qx, qy, qz and qw rotations (note qy and qz are swapped)
  int nMarkers;                     ///< Number of markers inside the rigid body (both visible and not visible)
  float error;                      ///< Error of the position in cm
  int nSamples;                     ///< Number of samples since last transmit
  bool posSampled;                  ///< If the position is sampled last sampling

  double vel_x, vel_y, vel_z;       ///< Sum of the (last_vel_* - current_vel_*) during nVelocitySamples
  struct EcefCoor_d ecef_vel;       ///< Last valid ECEF velocity in meters
  int nVelocitySamples;             ///< Number of velocity samples gathered
  int totalVelocitySamples;         ///< Total amount of velocity samples possible
  int nVelocityTransmit;            ///< Amount of transmits since last valid velocity transmit
};
struct RigidBody rigidBodies[MAX_RIGIDBODIES];    ///< All rigid bodies which are tracked

/** Mapping between rigid body and aircraft */
struct Aircraft {
  uint8_t ac_id;
  float lastSample;
  bool connected;
};
struct Aircraft aircrafts[MAX_RIGIDBODIES];                  ///< Mapping from rigid body ID to aircraft ID

/** Natnet socket connections */
struct FmsNetwork *natnet_data, *natnet_cmd;

/** Tracking location LTP and angle offset from north */
struct LtpDef_d tracking_ltp;       ///< The tracking system LTP definition
double tracking_offset_angle;       ///< The offset from the tracking system to the North in degrees

/** Save the latency from natnet */
float natnet_latency;

/** Parse the packet from NatNet */
void natnet_parse(unsigned char *in) {
  int i,j,k;

  // Create a pointer to go trough the packet
  char *ptr = (char *)in;
  printf_natnet("Begin Packet\n-------\n");

  // Message ID
  int MessageID = 0;
  memcpy(&MessageID, ptr, 2); ptr += 2;
  printf_natnet("Message ID : %d\n", MessageID);

  // Packet size
  int nBytes = 0;
  memcpy(&nBytes, ptr, 2); ptr += 2;
  printf_natnet("Byte count : %d\n", nBytes);

  if(MessageID == NAT_FRAMEOFDATA)      // FRAME OF MOCAP DATA packet
  {
    // Frame number
    int frameNumber = 0; memcpy(&frameNumber, ptr, 4); ptr += 4;
    printf_natnet("Frame # : %d\n", frameNumber);

    // ========== MARKERSETS ==========
    // Number of data sets (markersets, rigidbodies, etc)
    int nMarkerSets = 0; memcpy(&nMarkerSets, ptr, 4); ptr += 4;
    printf_natnet("Marker Set Count : %d\n", nMarkerSets);

    for (i=0; i < nMarkerSets; i++)
    {
      // Markerset name
      char szName[256];
      strcpy(szName, ptr);
      int nDataBytes = (int) strlen(szName) + 1;
      ptr += nDataBytes;
      printf_natnet("Model Name: %s\n", szName);

      // marker data
      int nMarkers = 0; memcpy(&nMarkers, ptr, 4); ptr += 4;
      printf_natnet("Marker Count : %d\n", nMarkers);

      for(j=0; j < nMarkers; j++)
      {
        float x = 0; memcpy(&x, ptr, 4); ptr += 4;
        float y = 0; memcpy(&y, ptr, 4); ptr += 4;
        float z = 0; memcpy(&z, ptr, 4); ptr += 4;
        printf_natnet("\tMarker %d : [x=%3.2f,y=%3.2f,z=%3.2f]\n",j,x,y,z);
      }
    }

    // Unidentified markers
    int nOtherMarkers = 0; memcpy(&nOtherMarkers, ptr, 4); ptr += 4;
    printf_natnet("Unidentified Marker Count : %d\n", nOtherMarkers);
    for(j=0; j < nOtherMarkers; j++)
    {
      float x = 0.0f; memcpy(&x, ptr, 4); ptr += 4;
      float y = 0.0f; memcpy(&y, ptr, 4); ptr += 4;
      float z = 0.0f; memcpy(&z, ptr, 4); ptr += 4;
      printf_natnet("\tMarker %d : pos = [%3.2f,%3.2f,%3.2f]\n",j,x,y,z);
    }

    // ========== RIGID BODIES ==========
    // Rigid bodies
    int nRigidBodies = 0;
    memcpy(&nRigidBodies, ptr, 4); ptr += 4;
    printf_natnet("Rigid Body Count : %d\n", nRigidBodies);

    // Check if there ie enough space for the rigid bodies
    if(nRigidBodies > MAX_RIGIDBODIES) {
      fprintf(stderr, "Could not sample all the rigid bodies because the amount of rigid bodies is bigger then %d (MAX_RIGIDBODIES).\r\n", MAX_RIGIDBODIES);
      exit(EXIT_FAILURE);
    }

    for (j=0; j < nRigidBodies; j++)
    {
      // rigid body pos/ori
      struct RigidBody old_rigid;
      memcpy(&old_rigid, &rigidBodies[j], sizeof(struct RigidBody));

      memcpy(&rigidBodies[j].id, ptr, 4); ptr += 4;
      memcpy(&rigidBodies[j].x, ptr, 4); ptr += 4;   //x --> X
      memcpy(&rigidBodies[j].z, ptr, 4); ptr += 4;   //y --> Z
      memcpy(&rigidBodies[j].y, ptr, 4); ptr += 4;   //z --> Y
      memcpy(&rigidBodies[j].qx, ptr, 4); ptr += 4;  //qx --> QX
      memcpy(&rigidBodies[j].qz, ptr, 4); ptr += 4;  //qy --> QZ
      memcpy(&rigidBodies[j].qy, ptr, 4); ptr += 4;  //qz --> QY
      memcpy(&rigidBodies[j].qw, ptr, 4); ptr += 4;  //qw --> QW
      printf_natnet("ID (%d) : %d\n", j, rigidBodies[j].id);
      printf_natnet("pos: [%3.2f,%3.2f,%3.2f]\n", rigidBodies[j].x,rigidBodies[j].y,rigidBodies[j].z);
      printf_natnet("ori: [%3.2f,%3.2f,%3.2f,%3.2f]\n", rigidBodies[j].qx,rigidBodies[j].qy,rigidBodies[j].qz,rigidBodies[j].qw);

      // Differentiate the position to get the speed (TODO: crossreference with labeled markers for occlussion)
      rigidBodies[j].totalVelocitySamples++;
      if(old_rigid.x != rigidBodies[j].x || old_rigid.y != rigidBodies[j].y || old_rigid.z != rigidBodies[j].z
        || old_rigid.qx != rigidBodies[j].qx || old_rigid.qy != rigidBodies[j].qy || old_rigid.qz != rigidBodies[j].qz || old_rigid.qw != rigidBodies[j].qw) {

        if(old_rigid.posSampled) {
          rigidBodies[j].vel_x += (rigidBodies[j].x - old_rigid.x);
          rigidBodies[j].vel_y += (rigidBodies[j].y - old_rigid.y);
          rigidBodies[j].vel_z += (rigidBodies[j].z - old_rigid.z);
          rigidBodies[j].nVelocitySamples++;
        }

        rigidBodies[j].nSamples++;
        rigidBodies[j].posSampled = TRUE;
      }
      else
        rigidBodies[j].posSampled = FALSE;

      // When marker id changed, reset the velocity
      if(old_rigid.id != rigidBodies[j].id) {
        rigidBodies[j].vel_x = 0;
        rigidBodies[j].vel_y = 0;
        rigidBodies[j].vel_z = 0;
        rigidBodies[j].nSamples = 0;
        rigidBodies[j].nVelocitySamples = 0;
        rigidBodies[j].totalVelocitySamples = 0;
        rigidBodies[j].posSampled = FALSE;
      }

      // Associated marker positions
      memcpy(&rigidBodies[j].nMarkers, ptr, 4); ptr += 4;
      printf_natnet("Marker Count: %d\n", rigidBodies[j].nMarkers);
      int nBytes = rigidBodies[j].nMarkers*3*sizeof(float);
      float* markerData = (float*)malloc(nBytes);
      memcpy(markerData, ptr, nBytes);
      ptr += nBytes;

      if(natnet_major >= 2)
      {
        // Associated marker IDs
        nBytes = rigidBodies[j].nMarkers*sizeof(int);
        int* markerIDs = (int*)malloc(nBytes);
        memcpy(markerIDs, ptr, nBytes);
        ptr += nBytes;

        // Associated marker sizes
        nBytes = rigidBodies[j].nMarkers*sizeof(float);
        float* markerSizes = (float*)malloc(nBytes);
        memcpy(markerSizes, ptr, nBytes);
        ptr += nBytes;

        for(k=0; k < rigidBodies[j].nMarkers; k++)
        {
          printf_natnet("\tMarker %d: id=%d\tsize=%3.1f\tpos=[%3.2f,%3.2f,%3.2f]\n", k, markerIDs[k], markerSizes[k], markerData[k*3], markerData[k*3+1],markerData[k*3+2]);
        }

        if(markerIDs)
          free(markerIDs);
        if(markerSizes)
          free(markerSizes);

      }
      else
      {
        for(k=0; k < rigidBodies[j].nMarkers; k++)
        {
          printf_natnet("\tMarker %d: pos = [%3.2f,%3.2f,%3.2f]\n", k, markerData[k*3], markerData[k*3+1],markerData[k*3+2]);
        }
      }
      if(markerData)
        free(markerData);

      if(natnet_major >= 2)
      {
        // Mean marker error
        memcpy(&rigidBodies[j].error, ptr, 4); ptr += 4;
        printf_natnet("Mean marker error: %3.8f\n", rigidBodies[j].error);
      }
    } // next rigid body

    // ========== SKELETONS ==========
    // Skeletons (version 2.1 and later)
    if(((natnet_major == 2) && (natnet_minor>0)) || (natnet_major>2))
    {
      int nSkeletons = 0;
      memcpy(&nSkeletons, ptr, 4); ptr += 4;
      printf_natnet("Skeleton Count : %d\n", nSkeletons);
      for (j=0; j < nSkeletons; j++)
      {
        // Skeleton id
        int skeletonID = 0;
        memcpy(&skeletonID, ptr, 4); ptr += 4;
        // # of rigid bodies (bones) in skeleton
        int nRigidBodies = 0;
        memcpy(&nRigidBodies, ptr, 4); ptr += 4;
        printf_natnet("Rigid Body Count : %d\n", nRigidBodies);
        for (j=0; j < nRigidBodies; j++)
        {
          // Rigid body pos/ori
          int ID = 0; memcpy(&ID, ptr, 4); ptr += 4;
          float x = 0.0f; memcpy(&x, ptr, 4); ptr += 4;
          float y = 0.0f; memcpy(&y, ptr, 4); ptr += 4;
          float z = 0.0f; memcpy(&z, ptr, 4); ptr += 4;
          float qx = 0; memcpy(&qx, ptr, 4); ptr += 4;
          float qy = 0; memcpy(&qy, ptr, 4); ptr += 4;
          float qz = 0; memcpy(&qz, ptr, 4); ptr += 4;
          float qw = 0; memcpy(&qw, ptr, 4); ptr += 4;
          printf_natnet("ID : %d\n", ID);
          printf_natnet("pos: [%3.2f,%3.2f,%3.2f]\n", x,y,z);
          printf_natnet("ori: [%3.2f,%3.2f,%3.2f,%3.2f]\n", qx,qy,qz,qw);

          // Sssociated marker positions
          int nRigidMarkers = 0;  memcpy(&nRigidMarkers, ptr, 4); ptr += 4;
          printf_natnet("Marker Count: %d\n", nRigidMarkers);
          int nBytes = nRigidMarkers*3*sizeof(float);
          float* markerData = (float*)malloc(nBytes);
          memcpy(markerData, ptr, nBytes);
          ptr += nBytes;

          // Associated marker IDs
          nBytes = nRigidMarkers*sizeof(int);
          int* markerIDs = (int*)malloc(nBytes);
          memcpy(markerIDs, ptr, nBytes);
          ptr += nBytes;

          // Associated marker sizes
          nBytes = nRigidMarkers*sizeof(float);
          float* markerSizes = (float*)malloc(nBytes);
          memcpy(markerSizes, ptr, nBytes);
          ptr += nBytes;

          for(k=0; k < nRigidMarkers; k++)
          {
            printf_natnet("\tMarker %d: id=%d\tsize=%3.1f\tpos=[%3.2f,%3.2f,%3.2f]\n", k, markerIDs[k], markerSizes[k], markerData[k*3], markerData[k*3+1],markerData[k*3+2]);
          }

          // Mean marker error
          float fError = 0.0f; memcpy(&fError, ptr, 4); ptr += 4;
          printf_natnet("Mean marker error: %3.2f\n", fError);

          // Release resources
          if(markerIDs)
            free(markerIDs);
          if(markerSizes)
            free(markerSizes);
          if(markerData)
            free(markerData);
        } // next rigid body
      } // next skeleton
    }

    // ========== LABELED MARKERS ==========
    // Labeled markers (version 2.3 and later)
    if( ((natnet_major == 2)&&(natnet_minor>=3)) || (natnet_major>2))
    {
      int nLabeledMarkers = 0;
      memcpy(&nLabeledMarkers, ptr, 4); ptr += 4;
      printf_natnet("Labeled Marker Count : %d\n", nLabeledMarkers);
      for (j=0; j < nLabeledMarkers; j++)
      {
        int ID = 0; memcpy(&ID, ptr, 4); ptr += 4;
        float x = 0.0f; memcpy(&x, ptr, 4); ptr += 4;
        float y = 0.0f; memcpy(&y, ptr, 4); ptr += 4;
        float z = 0.0f; memcpy(&z, ptr, 4); ptr += 4;
        float size = 0.0f; memcpy(&size, ptr, 4); ptr += 4;

        printf_natnet("ID  : %d\n", ID);
        printf_natnet("pos : [%3.2f,%3.2f,%3.2f]\n", x,y,z);
        printf_natnet("size: [%3.2f]\n", size);
      }
    }

    // Latency
    natnet_latency = 0.0f; memcpy(&natnet_latency, ptr, 4); ptr += 4;
    printf_natnet("latency : %3.3f\n", natnet_latency);

    // Timecode
    unsigned int timecode = 0;  memcpy(&timecode, ptr, 4);  ptr += 4;
    unsigned int timecodeSub = 0; memcpy(&timecodeSub, ptr, 4); ptr += 4;
    printf_natnet("timecode : %d %d", timecode, timecodeSub);

    // End of data tag
    int eod = 0; memcpy(&eod, ptr, 4); ptr += 4;
    printf_natnet("End Packet\n-------------\n");
  }
  else
  {
    printf("Error: Unrecognized packet type from Optitrack NatNet.\n");
  }
}

/** The transmitter periodic function */
gboolean timeout_transmit_callback(gpointer data) {
  int i;

  // Loop trough all the available rigidbodies (TODO: optimize)
  for(i = 0; i < MAX_RIGIDBODIES; i++) {
    // Check if ID's are correct
    if(rigidBodies[i].id >= MAX_RIGIDBODIES) {
      fprintf(stderr, "Could not parse rigid body %d from NatNet, because ID is higher then or equal to %d (MAX_RIGIDBODIES-1).\r\n", rigidBodies[i].id, MAX_RIGIDBODIES-1);
      exit(EXIT_FAILURE);
    }

    // Check if we want to transmit (follow) this rigid
    if(aircrafts[rigidBodies[i].id].ac_id == 0)
      continue;

    // When we don track anymore and timeout or start tracking
    if(rigidBodies[i].nSamples < 1
      && aircrafts[rigidBodies[i].id].connected
      && (natnet_latency - aircrafts[rigidBodies[i].id].lastSample) > CONNECTION_TIMEOUT) {
      aircrafts[rigidBodies[i].id].connected = FALSE;
      fprintf(stderr, "#error Lost tracking rigid id %d, aircraft id %d.\n",
        rigidBodies[i].id, aircrafts[rigidBodies[i].id].ac_id);
    }
    else if(rigidBodies[i].nSamples > 0 && !aircrafts[rigidBodies[i].id].connected) {
      fprintf(stderr, "#pragma message: Now tracking rigid id %d, aircraft id %d.\n",
        rigidBodies[i].id, aircrafts[rigidBodies[i].id].ac_id);
    }

    // Check if we still track the rigid
    if(rigidBodies[i].nSamples < 1)
      continue;

    // Update the last tracked
    aircrafts[rigidBodies[i].id].connected = TRUE;
    aircrafts[rigidBodies[i].id].lastSample = natnet_latency;

    // Defines to make easy use of paparazzi math
    struct EnuCoor_d pos, speed;
    struct EcefCoor_d ecef_pos;
    struct LlaCoor_d lla_pos;
    struct DoubleQuat orient;
    struct DoubleEulers orient_eulers;

    // Add the Optitrack angle to the x and y positions
    pos.x = cos(tracking_offset_angle) * rigidBodies[i].x + sin(tracking_offset_angle) * rigidBodies[i].y;
    pos.y = sin(tracking_offset_angle) * rigidBodies[i].x - cos(tracking_offset_angle) * rigidBodies[i].y;
    pos.z = rigidBodies[i].z;

    // Convert the position to ecef and lla based on the Optitrack LTP
    ecef_of_enu_point_d(&ecef_pos ,&tracking_ltp ,&pos);
    lla_of_ecef_d(&lla_pos, &ecef_pos);

    // Check if we have enough samples to estimate the velocity
    rigidBodies[i].nVelocityTransmit++;
    if(rigidBodies[i].nVelocitySamples >= min_velocity_samples) {
      // Calculate the derevative of the sum to get the correct velocity     (1 / freq_transmit) * (samples / total_samples)
      double sample_time = //((double)rigidBodies[i].nVelocitySamples / (double)rigidBodies[i].totalVelocitySamples) /
                              ((double)rigidBodies[i].nVelocityTransmit / (double)freq_transmit);
      rigidBodies[i].vel_x = rigidBodies[i].vel_x / sample_time;
      rigidBodies[i].vel_y = rigidBodies[i].vel_y / sample_time;
      rigidBodies[i].vel_z = rigidBodies[i].vel_z / sample_time;

      // Add the Optitrack angle to the x and y velocities
      speed.x = cos(tracking_offset_angle) * rigidBodies[i].vel_x + sin(tracking_offset_angle) * rigidBodies[i].vel_y;
      speed.y = sin(tracking_offset_angle) * rigidBodies[i].vel_x - cos(tracking_offset_angle) * rigidBodies[i].vel_y;
      speed.z = rigidBodies[i].vel_z;

      // Conver the speed to ecef based on the Optitrack LTP
      ecef_of_enu_vect_d(&rigidBodies[i].ecef_vel ,&tracking_ltp ,&speed);
    }

    // Copy the quaternions and convert to euler angles for the heading
    orient.qi = rigidBodies[i].qw;
    orient.qx = rigidBodies[i].qx;
    orient.qy = rigidBodies[i].qy;
    orient.qz = rigidBodies[i].qz;
    DOUBLE_EULERS_OF_QUAT(orient_eulers, orient);

    // Calculate the heading by adding the Natnet offset angle and normalizing it
    double heading = -orient_eulers.psi-tracking_offset_angle;
    NormRadAngle(heading);

    printf_debug("[%d -> %d]Samples: %d\t%d\t\tTiming: %3.3f latency\n", rigidBodies[i].id, aircrafts[rigidBodies[i].id].ac_id
      , rigidBodies[i].nSamples, rigidBodies[i].nVelocitySamples, natnet_latency);
    printf_debug("    Heading: %f\t\tPosition: %f\t%f\t%f\t\tVelocity: %f\t%f\t%f\n", DegOfRad(heading),
      rigidBodies[i].x, rigidBodies[i].y, rigidBodies[i].z,
      rigidBodies[i].ecef_vel.x, rigidBodies[i].ecef_vel.y, rigidBodies[i].ecef_vel.z);

    // Transmit the REMOTE_GPS packet on the ivy bus
    IvySendMsg("0 REMOTE_GPS %d %d %d %d %d %d %d %d %d %d %d %d %d %d", aircrafts[rigidBodies[i].id].ac_id,
      rigidBodies[i].nMarkers,                //uint8 Number of markers (sv_num)
      (int)(ecef_pos.x*100.0),                //int32 ECEF X in CM
      (int)(ecef_pos.y*100.0),                //int32 ECEF Y in CM
      (int)(ecef_pos.z*100.0),                //int32 ECEF Z in CM
      (int)(lla_pos.lat*10000000.0),          //int32 LLA latitude in rad*1e7
      (int)(lla_pos.lon*10000000.0),          //int32 LLA longitude in rad*1e7
      (int)(rigidBodies[i].z*1000.0),         //int32 LLA altitude in mm above elipsoid
      (int)(rigidBodies[i].z*1000.0),         //int32 HMSL height above mean sea level in mm
      (int)(rigidBodies[i].ecef_vel.x*100.0), //int32 ECEF velocity X in m/s
      (int)(rigidBodies[i].ecef_vel.y*100.0), //int32 ECEF velocity Y in m/s
      (int)(rigidBodies[i].ecef_vel.z*100.0), //int32 ECEF velocity Z in m/s
      0,
      (int)(heading*10000000.0));             //int32 Course in rad*1e7

    // Reset the velocity differentiator if we calculated the velocity
    if(rigidBodies[i].nVelocitySamples >= min_velocity_samples) {
      rigidBodies[i].vel_x = 0;
      rigidBodies[i].vel_y = 0;
      rigidBodies[i].vel_z = 0;
      rigidBodies[i].nVelocitySamples = 0;
      rigidBodies[i].totalVelocitySamples = 0;
      rigidBodies[i].nVelocityTransmit = 0;
    }

    rigidBodies[i].nSamples = 0;
  }

  return TRUE;
}

/** The NatNet sampler periodic function */
static gboolean sample_data(GIOChannel *chan, GIOCondition cond, gpointer data) {
  static unsigned char buffer_data[MAX_PACKETSIZE];
  static int bytes_data = 0;

  // Keep on reading until we have the whole packet
  bytes_data += network_read(natnet_data, buffer_data, MAX_PACKETSIZE);

  // Parse NatNet data
  if(bytes_data >= 2 && bytes_data >= buffer_data[1]) {
    natnet_parse(buffer_data);
    bytes_data = 0;
  }

  return TRUE;
}


/** Print the program help */
void print_help(char* filename) {
  static const char *usage =
    "Usage: %s [options]\n"
    " Options :\n"
    "   -h, --help                Display this help\n"
    "   -v, --verbose <level>     Verbosity level 0-2 (0)\n\n"

    "   -ac <rigid_id> <ac_id>    Use rigid ID for GPS of ac_id (multiple possible)\n\n"

    "   -multicast_addr <ip>      NatNet server multicast address (239.255.42.99)\n"
    "   -server <ip>              NatNet server IP address (255.255.255.255)\n"
    "   -version <id>             NatNet server version (2.5)\n"
    "   -data_port <port>         NatNet server data socket UDP port (1510)\n"
    "   -cmd_port <port>          NatNet server command socket UDP port (1511)\n\n"

    "   -ecef <x> <y> <z>         ECEF coordinates of the tracking system\n"
    "   -lla <lat> <lon> <alt>    Latitude, longitude and altitude of the tracking system\n"
    "   -offset_angle <degree>    Tracking system angle offset compared to the North in degrees\n\n"

    "   -tf <freq>                Transmit frequency to the ivy bus in hertz (60)\n"
    "   -vel_samples <samples>    Minimum amount of samples for the velocity differentiator (4)\n\n"

    "   -ivy_bus <address:port>   Ivy bus address and port (127.255.255.255:2010)\n";
  fprintf(stderr, usage, filename);
}

/** Check the amount of arguments */
void check_argcount(int argc, char** argv, int i, int expected) {
  if(i+expected >= argc) {
    fprintf(stderr, "Option %s expected %d arguments\r\n\r\n", argv[i], expected);
    print_help(argv[0]);
    exit(0);
  }
}

/** Parse the options from the commandline */
static void parse_options(int argc, char** argv) {
  int i, count_ac = 0;
  for(i = 1; i < argc; ++i) {

    // Print help
    if(strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-h") == 0) {
      print_help(argv[0]);
      exit(0);
    }
    // Set the verbosity level
    if(strcmp(argv[i], "--verbosity") == 0 || strcmp(argv[i], "-v") == 0) {
      check_argcount(argc, argv, i, 1);

      verbose = atoi(argv[++i]);
    }

    // Set an rigid body to ivy ac_id
    else if(strcmp(argv[i], "-ac") == 0) {
      check_argcount(argc, argv, i, 2);

      int rigid_id = atoi(argv[++i]);
      uint8_t ac_id = atoi(argv[++i]);

      if(rigid_id >= MAX_RIGIDBODIES) {
        fprintf(stderr, "Rigid body ID must be less then %d (MAX_RIGIDBODIES)\n\n", MAX_RIGIDBODIES);
        print_help(argv[0]);
        exit(EXIT_FAILURE);
      }
      aircrafts[rigid_id].ac_id = ac_id;
      count_ac++;
    }

    // Set the NatNet multicast address
    else if(strcmp(argv[i], "-multicast_addr") == 0) {
      check_argcount(argc, argv, i, 1);

      natnet_multicast_addr = argv[++i];
    }
    // Set the NatNet server ip address
    else if(strcmp(argv[i], "-server") == 0) {
      check_argcount(argc, argv, i, 1);

      natnet_addr = argv[++i];
    }
    // Set the NatNet server version
    else if(strcmp(argv[i], "-version") == 0) {
      check_argcount(argc, argv, i, 1);

      float version = atof(argv[++i]);
      natnet_major = (uint8_t)version;
      natnet_minor = (uint8_t)(version * 10.0) % 10;
    }
    // Set the NatNet server data port
    else if(strcmp(argv[i], "-data_port") == 0) {
      check_argcount(argc, argv, i, 1);

      natnet_data_port = atoi(argv[++i]);
    }
    // Set the NatNet server command port
    else if(strcmp(argv[i], "-cmd_port") == 0) {
      check_argcount(argc, argv, i, 1);

      natnet_cmd_port = atoi(argv[++i]);
    }

    // Set the Tracking system position in ECEF
    else if (strcmp(argv[i], "-ecef") == 0) {
      check_argcount(argc, argv, i, 3);

      struct EcefCoor_d tracking_ecef;
      tracking_ecef.x  = atof(argv[++i]);
      tracking_ecef.y  = atof(argv[++i]);
      tracking_ecef.z  = atof(argv[++i]);
      ltp_def_from_ecef_d(&tracking_ltp, &tracking_ecef);
    }
    // Set the tracking system position in LLA
    else if (strcmp(argv[i], "-lla") == 0) {
      check_argcount(argc, argv, i, 3);

      struct EcefCoor_d tracking_ecef;
      struct LlaCoor_d tracking_lla;
      tracking_lla.lat  = atof(argv[++i]);
      tracking_lla.lon  = atof(argv[++i]);
      tracking_lla.alt  = atof(argv[++i]);
      ecef_of_lla_d(&tracking_ecef, &tracking_lla);
      ltp_def_from_ecef_d(&tracking_ltp, &tracking_ecef);
    }
    // Set the tracking system offset angle in degrees
    else if(strcmp(argv[i], "-offset_angle") == 0) {
      check_argcount(argc, argv, i, 1);

      tracking_offset_angle = atof(argv[++i]);
    }

    // Set the transmit frequency
    else if(strcmp(argv[i], "-tf") == 0) {
      check_argcount(argc, argv, i, 1);

      freq_transmit = atoi(argv[++i]);
    }
    // Set the minimum amount of velocity samples for the differentiator
    else if(strcmp(argv[i], "-vel_samples") == 0) {
      check_argcount(argc, argv, i, 1);

      min_velocity_samples = atoi(argv[++i]);
    }

    // Set the ivy bus
    else if(strcmp(argv[i], "-ivy_bus") == 0) {
      check_argcount(argc, argv, i, 1);

      ivy_bus = argv[++i];
    }

    // Unknown option
    else {
      fprintf(stderr, "Unknown option %s\r\n\r\n", argv[i]);
      print_help(argv[0]);
      exit(0);
    }
  }

  // Check if at least one aircraft is set
  if(count_ac < 1) {
    fprintf(stderr, "You must specify at least one aircraft (-ac <rigid_id> <ac_id>)\n\n");
    print_help(argv[0]);
    exit(EXIT_FAILURE);
  }
}

int main(int argc, char** argv)
{
  // Set the default tracking system position and angle
  struct EcefCoor_d tracking_ecef;
  tracking_ecef.x = 3924304;
  tracking_ecef.y = 300360;
  tracking_ecef.z = 5002162;
  tracking_offset_angle = 123.0 / 57.6;
  ltp_def_from_ecef_d(&tracking_ltp, &tracking_ecef);

  // Parse the options from cmdline
  parse_options(argc, argv);
  printf_debug("Tracking system Latitude: %f Longitude: %f Offset to North: %f degrees\n", DegOfRad(tracking_ltp.lla.lat), DegOfRad(tracking_ltp.lla.lon), DegOfRad(tracking_offset_angle));

  // Create the network connections
  printf_debug("Starting NatNet listening (multicast address: %s, data port: %d, version: %d.%d)\n", natnet_multicast_addr, natnet_data_port, natnet_major, natnet_minor);
  natnet_data = network_new("", -1, natnet_data_port, 0); // Only receiving
  network_subscribe_multicast(natnet_data, natnet_multicast_addr);
  network_set_recvbuf(natnet_data, 0x100000); // 1MB

  printf_debug("Starting NatNet command socket (server address: %s, command port: %d)\n", natnet_addr, natnet_cmd_port);
  natnet_cmd = network_new(natnet_addr, natnet_cmd_port, 0, 1);
  network_set_recvbuf(natnet_cmd, 0x100000); // 1MB

  // Create the Ivy Client
  GMainLoop *ml =  g_main_loop_new(NULL, FALSE);
  IvyInit("natnet2ivy", "natnet2ivy READY", 0, 0, 0, 0);
  IvyStart(ivy_bus);

  // Create the main timers
  printf_debug("Starting transmitting and sampling timeouts (transmitting frequency: %dHz, minimum velocity samples: %d)\n",
    freq_transmit, min_velocity_samples);
  g_timeout_add(1000/freq_transmit, timeout_transmit_callback, NULL);

  GIOChannel *sk = g_io_channel_unix_new(natnet_data->socket_in);
  g_io_add_watch(sk, G_IO_IN | G_IO_NVAL | G_IO_HUP,
                 sample_data, NULL);

  // Run the main loop
  g_main_loop_run(ml);

  return 0;
}