]> git.mxchange.org Git - flightgear.git/blobdiff - src/FDM/JSBSim/FGState.cpp
- fixed fuel-need calculations
[flightgear.git] / src / FDM / JSBSim / FGState.cpp
index 59773edb45fdaf6daacf12f6cc0e45f213ca5db3..2dc11a08e6508d1623fc093245484a0a2c31cda5 100644 (file)
-/*******************************************************************************
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
                                                                        
  Module:       FGState.cpp
  Author:       Jon Berndt
  Date started: 11/17/98
  Called by:    FGFDMExec and accessed by all models.
-
  ------------- Copyright (C) 1999  Jon S. Berndt (jsb@hal-pc.org) -------------
-
  This program 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 of the License, or (at your option) any later
  version.
-
  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.
-
  Further information about the GNU General Public License can also be found on
  the world wide web at http://www.gnu.org.
-
 FUNCTIONAL DESCRIPTION
 --------------------------------------------------------------------------------
 See header file.
-
 HISTORY
 --------------------------------------------------------------------------------
 11/17/98   JSB   Created
-
-********************************************************************************
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 INCLUDES
-*******************************************************************************/
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
 #ifdef FGFS
-#  include <Include/compiler.h>
-#  ifdef FG_HAVE_STD_INCLUDES
-#    include <cmath>
-#  else
+#  include <simgear/compiler.h>
+#  include <math.h>
+#else
+#  if defined(sgi) && !defined(__GNUC__)
 #    include <math.h>
+#  else
+#    include <cmath>
 #  endif
-#else
-#  include <cmath>
+#endif
+
+#ifdef _MSC_VER
+#define snprintf _snprintf
 #endif
 
 #include "FGState.h"
-#include "FGFDMExec.h"
-#include "FGAtmosphere.h"
-#include "FGFCS.h"
-#include "FGAircraft.h"
-#include "FGTranslation.h"
-#include "FGRotation.h"
-#include "FGPosition.h"
-#include "FGAuxiliary.h"
-#include "FGOutput.h"
 
-/*******************************************************************************
-************************************ CODE **************************************
-*******************************************************************************/
+static const char *IdSrc = "$Id$";
+static const char *IdHdr = ID_STATE;
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+MACROS
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+
+#define RegisterVariable(ID,DEF) coeffdef[#ID] = ID; paramdef[ID] = DEF
+
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+CLASS IMPLEMENTATION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+//
+// For every term registered here there must be a corresponding handler in
+// GetParameter() below that retrieves that parameter. Also, there must be an
+// entry in the enum eParam definition in FGJSBBase.h. The ID is what must be used
+// in any config file entry which references that item.
 
 FGState::FGState(FGFDMExec* fdex)
 {
   FDMExec = fdex;
 
-  Vt = 0.0;
-  latitude = longitude = 0.0;
-  adot = bdot = 0.0;
-  h = 0.0;
   a = 1000.0;
-  qbar = 0.0;
   sim_time = 0.0;
   dt = 1.0/120.0;
+  ActiveEngine = -1;
+
+  Aircraft     = FDMExec->GetAircraft();
+  Translation  = FDMExec->GetTranslation();
+  Rotation     = FDMExec->GetRotation();
+  Position     = FDMExec->GetPosition();
+  FCS          = FDMExec->GetFCS();
+  Output       = FDMExec->GetOutput();
+  Atmosphere   = FDMExec->GetAtmosphere();
+  Aerodynamics = FDMExec->GetAerodynamics();
+  GroundReactions = FDMExec->GetGroundReactions();
+  Propulsion      = FDMExec->GetPropulsion();
+
+  RegisterVariable(FG_TIME,           " time "           );
+  RegisterVariable(FG_QBAR,           " qbar "           );
+  RegisterVariable(FG_WINGAREA,       " wing_area "      );
+  RegisterVariable(FG_WINGSPAN,       " wingspan "       );
+  RegisterVariable(FG_CBAR,           " cbar "           );
+  RegisterVariable(FG_ALPHA,          " alpha "          );
+  RegisterVariable(FG_ALPHADOT,       " alphadot "       );
+  RegisterVariable(FG_BETA,           " beta "           );
+  RegisterVariable(FG_ABETA,          " |beta| "         );
+  RegisterVariable(FG_BETADOT,        " betadot "        );
+  RegisterVariable(FG_PHI,            " roll_angle "     );
+  RegisterVariable(FG_THT,            " pitch_angle "    );
+  RegisterVariable(FG_PSI,            " heading_angle "  );
+  RegisterVariable(FG_PITCHRATE,      " pitch_rate "     );
+  RegisterVariable(FG_ROLLRATE,       " roll_rate "      );
+  RegisterVariable(FG_YAWRATE,        " yaw_rate "       );
+  RegisterVariable(FG_AEROQ,          " aero_pitch_rate ");
+  RegisterVariable(FG_AEROP,          " aero_roll_rate " );
+  RegisterVariable(FG_AEROR,          " aero_yaw_rate "  );
+  RegisterVariable(FG_CL_SQRD,        " Clift_sqrd "     );
+  RegisterVariable(FG_MACH,           " mach "           );
+  RegisterVariable(FG_ALTITUDE,       " altitude "       );
+  RegisterVariable(FG_BI2VEL,         " BI2Vel "         );
+  RegisterVariable(FG_CI2VEL,         " CI2Vel "         );
+  RegisterVariable(FG_ELEVATOR_POS,   " elevator_pos "   );
+  RegisterVariable(FG_AILERON_POS,    " aileron_pos "    );
+  RegisterVariable(FG_RUDDER_POS,     " rudder_pos "     );
+  RegisterVariable(FG_SPDBRAKE_POS,   " speedbrake_pos " );
+  RegisterVariable(FG_SPOILERS_POS,   " spoiler_pos "    );
+  RegisterVariable(FG_FLAPS_POS,      " flaps_pos "      );
+  RegisterVariable(FG_GEAR_POS,       " gear_pos "       );
+  RegisterVariable(FG_ELEVATOR_CMD,   " elevator_cmd "   );
+  RegisterVariable(FG_AILERON_CMD,    " aileron_cmd "    );
+  RegisterVariable(FG_RUDDER_CMD,     " rudder_cmd "     );
+  RegisterVariable(FG_SPDBRAKE_CMD,   " speedbrake_cmd " );
+  RegisterVariable(FG_SPOILERS_CMD,   " spoiler_cmd "    );
+  RegisterVariable(FG_FLAPS_CMD,      " flaps_cmd "      );
+  RegisterVariable(FG_THROTTLE_CMD,   " throttle_cmd "   );
+  RegisterVariable(FG_GEAR_CMD,       " gear_cmd "       );
+  RegisterVariable(FG_THROTTLE_POS,   " throttle_pos "   );
+  RegisterVariable(FG_MIXTURE_CMD,    " mixture_cmd "    );
+  RegisterVariable(FG_MIXTURE_POS,    " mixture_pos "    );
+  RegisterVariable(FG_MAGNETO_CMD,    " magneto_cmd "    );
+  RegisterVariable(FG_STARTER_CMD,    " starter_cmd "    );
+  RegisterVariable(FG_ACTIVE_ENGINE,  " active_engine "  );
+  RegisterVariable(FG_HOVERB,         " height/span "    );
+  RegisterVariable(FG_PITCH_TRIM_CMD, " pitch_trim_cmd " );
+  RegisterVariable(FG_YAW_TRIM_CMD,   " yaw_trim_cmd " );
+  RegisterVariable(FG_ROLL_TRIM_CMD,  " roll_trim_cmd " );
+  RegisterVariable(FG_LEFT_BRAKE_CMD, " left_brake_cmd " );
+  RegisterVariable(FG_RIGHT_BRAKE_CMD," right_brake_cmd ");
+  RegisterVariable(FG_CENTER_BRAKE_CMD," center_brake_cmd ");
+  RegisterVariable(FG_ALPHAH,          " h-tail alpha " );
+  RegisterVariable(FG_ALPHAW,          " wing alpha " );
+  RegisterVariable(FG_LBARH,           " h-tail arm " );
+  RegisterVariable(FG_LBARV,           " v-tail arm " );
+  RegisterVariable(FG_HTAILAREA,       " h-tail area " );
+  RegisterVariable(FG_VTAILAREA,       " v-tail area " );
+  RegisterVariable(FG_VBARH,           " h-tail volume " );
+  RegisterVariable(FG_VBARV,           " v-tail volume " );
+  RegisterVariable(FG_SET_LOGGING,    " data_logging "   );
+
+  Debug(0);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGState::~FGState()
+{
+  Debug(1);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGState::GetParameter(eParam val_idx) {
+  double scratch;
+  
+  switch(val_idx) {
+  case FG_TIME:
+    return sim_time;
+  case FG_QBAR:
+    return Translation->Getqbar();
+  case FG_WINGAREA:
+    return Aircraft->GetWingArea();
+  case FG_WINGSPAN:
+    return Aircraft->GetWingSpan();
+  case FG_CBAR:
+    return Aircraft->Getcbar();
+  case FG_LBARH:
+    return Aircraft->Getlbarh();
+  case FG_LBARV:
+    return Aircraft->Getvbarh();
+  case FG_HTAILAREA:
+    return Aircraft->GetHTailArea();
+  case FG_VTAILAREA:
+    return Aircraft->GetVTailArea();
+  case FG_VBARH:
+    return Aircraft->Getvbarh();
+  case FG_VBARV:
+    return Aircraft->Getvbarv();
+  case FG_ALPHA:
+    return Translation->Getalpha();
+  case FG_ALPHAW:
+    return  Translation->Getalpha() + Aircraft->GetWingIncidence();
+  case FG_ALPHADOT:
+    return Translation->Getadot();
+  case FG_BETA:
+    return Translation->Getbeta();
+  case FG_ABETA:
+    return fabs(Translation->Getbeta());   
+  case FG_BETADOT:
+    return Translation->Getbdot();
+  case FG_PHI:
+    return Rotation->Getphi();
+  case FG_THT:
+    return Rotation->Gettht();
+  case FG_PSI:
+    return Rotation->Getpsi();
+  case FG_PITCHRATE:
+    return Rotation->GetPQR(eQ);
+  case FG_ROLLRATE:
+    return Rotation->GetPQR(eP);
+  case FG_YAWRATE:
+    return Rotation->GetPQR(eR);
+  case FG_AEROP:
+    return Rotation->GetAeroPQR(eP);
+  case FG_AEROQ:
+    return Rotation->GetAeroPQR(eQ);
+  case FG_AEROR:
+    return Rotation->GetAeroPQR(eR);
+  case FG_CL_SQRD:
+    if (Translation->Getqbar() > 0.00)
+      scratch = Aerodynamics->GetvLastFs(eLift)/(Aircraft->GetWingArea()*Translation->Getqbar());
+    else
+      scratch = 0.0;
+    return scratch*scratch;                                       
+  case FG_ELEVATOR_POS:
+    return FCS->GetDePos();
+  case FG_AILERON_POS:
+    return FCS->GetDaPos();
+  case FG_RUDDER_POS:
+    return FCS->GetDrPos();
+  case FG_SPDBRAKE_POS:
+    return FCS->GetDsbPos();
+  case FG_SPOILERS_POS:
+    return FCS->GetDspPos();
+  case FG_FLAPS_POS:
+    return FCS->GetDfPos();
+  case FG_ELEVATOR_CMD:
+    return FCS->GetDeCmd();
+  case FG_AILERON_CMD:
+    return FCS->GetDaCmd();
+  case FG_RUDDER_CMD:
+    return FCS->GetDrCmd();
+  case FG_SPDBRAKE_CMD:
+    return FCS->GetDsbCmd();
+  case FG_SPOILERS_CMD:
+    return FCS->GetDspCmd();
+  case FG_FLAPS_CMD:
+    return FCS->GetDfCmd();
+  case FG_MACH:
+    return Translation->GetMach();
+  case FG_ALTITUDE:
+    return Position->Geth();
+  case FG_BI2VEL:
+    if(Translation->GetVt() > 0)
+        return Aircraft->GetWingSpan()/(2.0 * Translation->GetVt());
+    else
+        return 0;
+  case FG_CI2VEL:
+    if(Translation->GetVt() > 0)
+        return Aircraft->Getcbar()/(2.0 * Translation->GetVt());
+    else
+        return 0;
+  case FG_THROTTLE_CMD:
+    if (ActiveEngine < 0) return FCS->GetThrottleCmd(0);
+    else return FCS->GetThrottleCmd(ActiveEngine);
+  case FG_THROTTLE_POS:
+    if (ActiveEngine < 0) return FCS->GetThrottlePos(0);
+    else return FCS->GetThrottlePos(ActiveEngine);
+  case FG_MAGNETO_CMD:
+    if (ActiveEngine < 0) return Propulsion->GetEngine(0)->GetMagnetos();
+    else return Propulsion->GetEngine(ActiveEngine)->GetMagnetos();
+  case FG_STARTER_CMD:
+    if (ActiveEngine < 0) {
+      if (Propulsion->GetEngine(0)->GetStarter()) return 1.0;
+      else return 0.0;
+    } else {
+      if (Propulsion->GetEngine(ActiveEngine)->GetStarter()) return 1.0;
+      else return 0.0;
+    }
+  case FG_MIXTURE_CMD:
+    if (ActiveEngine < 0) return FCS->GetMixtureCmd(0);
+    else return FCS->GetMixtureCmd(ActiveEngine);
+  case FG_MIXTURE_POS:
+    if (ActiveEngine < 0) return FCS->GetMixturePos(0);
+    else return FCS->GetMixturePos(ActiveEngine);
+  case FG_HOVERB:
+    return Position->GetHOverBMAC();
+  case FG_PITCH_TRIM_CMD:
+    return FCS->GetPitchTrimCmd();
+  case FG_YAW_TRIM_CMD:
+    return FCS->GetYawTrimCmd();
+  case FG_ROLL_TRIM_CMD:
+    return FCS->GetRollTrimCmd();
+  case FG_GEAR_CMD:
+    return FCS->GetGearCmd();
+  case FG_GEAR_POS:
+    return FCS->GetGearPos();    
+  default:
+    cerr << "FGState::GetParameter() - No handler for parameter " << paramdef[val_idx] << endl;
+    return 0.0;
+  }
+  return 0;
 }
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+double FGState::GetParameter(string val_string) {
+  return GetParameter(coeffdef[val_string]);
+}
 
-FGState::~FGState(void)
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+eParam FGState::GetParameterIndex(string val_string)
 {
+  return coeffdef[val_string];
 }
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGState::SetParameter(eParam val_idx, double val)
+{
+  unsigned i;
+
+  switch(val_idx) {
+  case FG_ELEVATOR_POS:
+    FCS->SetDePos(val);
+    break;
+  case FG_AILERON_POS:
+    FCS->SetDaPos(val);
+    break;
+  case FG_RUDDER_POS:
+    FCS->SetDrPos(val);
+    break;
+  case FG_SPDBRAKE_POS:
+    FCS->SetDsbPos(val);
+    break;
+  case FG_SPOILERS_POS:
+    FCS->SetDspPos(val);
+    break;
+  case FG_FLAPS_POS:
+    FCS->SetDfPos(val);
+    break;
+  case FG_THROTTLE_POS:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        FCS->SetThrottlePos(i,val);
+           }
+         } else {
+      FCS->SetThrottlePos(ActiveEngine,val);
+         }
+    break;
+  case FG_MIXTURE_POS:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        FCS->SetMixturePos(i,val);
+           }
+         } else {
+      FCS->SetMixturePos(ActiveEngine,val);
+         }
+    break;
+
+  case FG_ELEVATOR_CMD:
+    FCS->SetDeCmd(val);
+    break;
+  case FG_AILERON_CMD:
+    FCS->SetDaCmd(val);
+    break;
+  case FG_RUDDER_CMD:
+    FCS->SetDrCmd(val);
+    break;
+  case FG_SPDBRAKE_CMD:
+    FCS->SetDsbCmd(val);
+    break;
+  case FG_SPOILERS_CMD:
+    FCS->SetDspCmd(val);
+    break;
+  case FG_FLAPS_CMD:
+    FCS->SetDfCmd(val);
+    break;
+  case FG_THROTTLE_CMD:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        FCS->SetThrottleCmd(i,val);
+           }
+         } else {
+      FCS->SetThrottleCmd(ActiveEngine,val);
+         }
+    break;
+  case FG_MIXTURE_CMD:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        FCS->SetMixtureCmd(i,val);
+           }
+         } else {
+      FCS->SetMixtureCmd(ActiveEngine,val);
+         }
+    break;
+  case FG_MAGNETO_CMD:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        Propulsion->GetEngine(i)->SetMagnetos((int)val);
+      }
+    } else {
+      Propulsion->GetEngine(ActiveEngine)->SetMagnetos((int)val);
+    }
+    break;
+  case FG_STARTER_CMD:
+    if (ActiveEngine == -1) {
+      for (i=0; i<Propulsion->GetNumEngines(); i++) {
+        if (val < 0.001) 
+          Propulsion->GetEngine(i)->SetStarter(false);
+        else if (val >=  0.001)
+          Propulsion->GetEngine(i)->SetStarter(true);
+      }
+    } else {
+      Propulsion->GetEngine(ActiveEngine)->SetStarter(true);
+    }
+    break;
+  case FG_ACTIVE_ENGINE:
+    ActiveEngine = (int)val;
+    break;
+
+  case FG_LEFT_BRAKE_CMD:
+    FCS->SetLBrake(val);
+    break;
+  case FG_CENTER_BRAKE_CMD:
+    FCS->SetCBrake(val);
+    break;
+  case FG_RIGHT_BRAKE_CMD:
+    FCS->SetRBrake(val);
+    break;
+  case FG_GEAR_CMD:
+    FCS->SetGearCmd(val);
+    break;
+  case  FG_GEAR_POS:
+    FCS->SetGearPos(val);
+    break; 
+  case FG_SET_LOGGING:
+    if      (val < -0.01) Output->Disable();
+    else if (val >  0.01) Output->Enable();
+    else                  Output->Toggle();
+    break;
+
+  default:
+    cerr << "Parameter '" << val_idx << "' (" << paramdef[val_idx] << ") not handled" << endl;
+  }
+}
 
 //***************************************************************************
 //
 // Reset: Assume all angles READ FROM FILE IN DEGREES !!
 //
 
-bool FGState::Reset(string path, string fname)
+bool FGState::Reset(string path, string acname, string fname)
 {
   string resetDef;
-  float U, V, W;
-  float phi, tht, psi;
-
-  resetDef = path + "/" + FDMExec->GetAircraft()->GetAircraftName() + "/" + fname;
-
-  ifstream resetfile(resetDef.c_str());
-
-  if (resetfile) {
-    resetfile >> U;
-    resetfile >> V;
-    resetfile >> W;
-    resetfile >> latitude;
-    resetfile >> longitude;
-    resetfile >> phi;
-    resetfile >> tht;
-    resetfile >> psi;
-    resetfile >> h;
-    resetfile.close();
-
-    Initialize(U, V, W, phi*DEGTORAD, tht*DEGTORAD, psi*DEGTORAD,
-               latitude*DEGTORAD, longitude*DEGTORAD, h);
-
-    return true;
-  } else {
-    cerr << "Unable to load reset file " << fname << endl;
+  string token="";
+
+  double U, V, W;
+  double phi, tht, psi;
+  double latitude, longitude, h;
+  double wdir, wmag, wnorth, weast;
+
+# ifndef macintosh
+  resetDef = path + "/" + acname + "/" + fname + ".xml";
+# else
+  resetDef = path + ";" + acname + ";" + fname + ".xml";
+# endif
+
+  FGConfigFile resetfile(resetDef);
+  if (!resetfile.IsOpen()) return false;
+
+  resetfile.GetNextConfigLine();
+  token = resetfile.GetValue();
+  if (token != string("initialize")) {
+    cerr << "The reset file " << resetDef
+         << " does not appear to be a reset file" << endl;
     return false;
+  } else {
+    resetfile.GetNextConfigLine();
+    resetfile >> token;
+    cout << "Resetting using: " << token << endl << endl;
+  }
+  
+  while (token != string("/initialize") && token != string("EOF")) {
+    if (token == "UBODY") resetfile >> U;
+    if (token == "VBODY") resetfile >> V;
+    if (token == "WBODY") resetfile >> W;
+    if (token == "LATITUDE") resetfile >> latitude;
+    if (token == "LONGITUDE") resetfile >> longitude;
+    if (token == "PHI") resetfile >> phi;
+    if (token == "THETA") resetfile >> tht;
+    if (token == "PSI") resetfile >> psi;
+    if (token == "ALTITUDE") resetfile >> h;
+    if (token == "WINDDIR") resetfile >> wdir;
+    if (token == "VWIND") resetfile >> wmag;
+
+    resetfile >> token;
   }
+  
+  
+  Position->SetLatitude(latitude*degtorad);
+  Position->SetLongitude(longitude*degtorad);
+  Position->Seth(h);
+
+  wnorth = wmag*ktstofps*cos(wdir*degtorad);
+  weast = wmag*ktstofps*sin(wdir*degtorad);
+  
+  Initialize(U, V, W, phi*degtorad, tht*degtorad, psi*degtorad,
+               latitude*degtorad, longitude*degtorad, h, wnorth, weast, 0.0);
+
+  return true;
 }
 
 //***************************************************************************
@@ -125,65 +524,65 @@ bool FGState::Reset(string path, string fname)
 // Initialize: Assume all angles GIVEN IN RADIANS !!
 //
 
-void FGState::Initialize(float U, float V, float W,
-                         float phi, float tht, float psi,
-                         float Latitude, float Longitude, float H)
+void FGState::Initialize(double U, double V, double W,
+                         double phi, double tht, double psi,
+                         double Latitude, double Longitude, double H,
+                         double wnorth, double weast, double wdown)
 {
-  float alpha, beta, gamma;
-  float Q0, Q1, Q2, Q3;
-  float T[4][4];
-
-  latitude = Latitude;
-  longitude = Longitude;
-  h = H;
-
-  gamma = 0.0;
-  if (W != 0.0)
-    alpha = U*U > 0.0 ? atan2(W, U) : 0.0;
+  double alpha, beta;
+  double qbar, Vt;
+  FGColumnVector3 vAeroUVW;
+
+  Position->SetLatitude(Latitude);
+  Position->SetLongitude(Longitude);
+  Position->Seth(H);
+
+  Atmosphere->Run();
+  
+  vLocalEuler << phi << tht << psi;
+  Rotation->SetEuler(vLocalEuler);
+
+  InitMatrices(phi, tht, psi);
+  
+  vUVW << U << V << W;
+  Translation->SetUVW(vUVW);
+  
+  Atmosphere->SetWindNED(wnorth, weast, wdown);
+  
+  vAeroUVW = vUVW + mTl2b*Atmosphere->GetWindNED();
+  
+  if (vAeroUVW(eW) != 0.0)
+    alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
   else
     alpha = 0.0;
-  if (V != 0.0)
-    beta = U*U+W*W > 0.0 ? atan2(V, (fabs(U)/U)*sqrt(U*U + W*W)) : 0.0;
+  if (vAeroUVW(eV) != 0.0)
+    beta = vAeroUVW(eU)*vAeroUVW(eU)+vAeroUVW(eW)*vAeroUVW(eW) > 0.0 ? atan2(vAeroUVW(eV), (fabs(vAeroUVW(eU))/vAeroUVW(eU))*sqrt(vAeroUVW(eU)*vAeroUVW(eU) + vAeroUVW(eW)*vAeroUVW(eW))) : 0.0;
   else
     beta = 0.0;
 
-  FDMExec->GetTranslation()->SetUVW(U, V, W);
-  FDMExec->GetRotation()->SetEuler(phi, tht, psi);
-  FDMExec->GetTranslation()->SetABG(alpha, beta, gamma);
+  Translation->SetAB(alpha, beta);
 
   Vt = sqrt(U*U + V*V + W*W);
-  qbar = 0.5*(U*U + V*V + W*W)*FDMExec->GetAtmosphere()->CalcRho(h);
-
-  Q0 =  sin(psi*0.5)*sin(tht*0.5)*sin(phi*0.5) + cos(psi*0.5)*cos(tht*0.5)*cos(phi*0.5);
-  Q1 = -sin(psi*0.5)*sin(tht*0.5)*cos(phi*0.5) + cos(psi*0.5)*cos(tht*0.5)*sin(phi*0.5);
-  Q2 =  sin(psi*0.5)*cos(tht*0.5)*sin(phi*0.5) + cos(psi*0.5)*sin(tht*0.5)*cos(phi*0.5);
-  Q3 =  sin(psi*0.5)*cos(tht*0.5)*cos(phi*0.5) - cos(psi*0.5)*sin(tht*0.5)*sin(phi*0.5);
-
-  FDMExec->GetRotation()->SetQ0123(Q0, Q1, Q2, Q3);
-
-  T[1][1] = Q0*Q0 + Q1*Q1 - Q2*Q2 - Q3*Q3;
-  T[1][2] = 2*(Q1*Q2 + Q0*Q3);
-  T[1][3] = 2*(Q1*Q3 - Q0*Q2);
-  T[2][1] = 2*(Q1*Q2 - Q0*Q3);
-  T[2][2] = Q0*Q0 - Q1*Q1 + Q2*Q2 - Q3*Q3;
-  T[2][3] = 2*(Q2*Q3 + Q0*Q1);
-  T[3][1] = 2*(Q1*Q3 + Q0*Q2);
-  T[3][2] = 2*(Q2*Q3 - Q0*Q1);
-  T[3][3] = Q0*Q0 - Q1*Q1 - Q2*Q2 + Q3*Q3;
-
-  FDMExec->GetPosition()->SetT(T[1][1], T[1][2], T[1][3],
-                               T[2][1], T[2][2], T[2][3],
-                               T[3][1], T[3][2], T[3][3]);
-  DisplayData();
-}
+  Translation->SetVt(Vt);
 
+  Translation->SetMach(Vt/Atmosphere->GetSoundSpeed());
 
-void FGState::Initialize(FGInitialCondition *FGIC)
-{
+  qbar = 0.5*(U*U + V*V + W*W)*Atmosphere->GetDensity();
+  Translation->Setqbar(qbar);
 
-  float tht,psi,phi;
-  float U,V,W;
+  vLocalVelNED = mTb2l*vUVW;
+  Position->SetvVel(vLocalVelNED);
+}
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGState::Initialize(FGInitialCondition *FGIC) {
+
+  double tht,psi,phi;
+  double U, V, W, h;
+  double latitude, longitude;
+  double wnorth,weast, wdown;
+  
   latitude = FGIC->GetLatitudeRadIC();
   longitude = FGIC->GetLongitudeRadIC();
   h = FGIC->GetAltitudeFtIC();
@@ -193,25 +592,33 @@ void FGState::Initialize(FGInitialCondition *FGIC)
   tht = FGIC->GetThetaRadIC();
   phi = FGIC->GetPhiRadIC();
   psi = FGIC->GetPsiRadIC();
-
-  Initialize(U, V, W, phi, tht, psi,latitude, longitude, h);
+  wnorth = FGIC->GetWindNFpsIC();
+  weast = FGIC->GetWindEFpsIC();
+  wdown = FGIC->GetWindDFpsIC();
+  
+  Position->SetSeaLevelRadius( FGIC->GetSeaLevelRadiusFtIC() );
+  Position->SetRunwayRadius( FGIC->GetSeaLevelRadiusFtIC() + 
+                                             FGIC->GetTerrainAltitudeFtIC() );
+
+  // need to fix the wind speed args, here.  
+  Initialize(U, V, W, phi, tht, psi, latitude, longitude, h, wnorth, weast, wdown);
 }
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-bool FGState::StoreData(string fname)
-{
+bool FGState::StoreData(string fname) {
   ofstream datafile(fname.c_str());
 
   if (datafile) {
-    datafile << FDMExec->GetTranslation()->GetU();
-    datafile << FDMExec->GetTranslation()->GetV();
-    datafile << FDMExec->GetTranslation()->GetW();
-    datafile << latitude;
-    datafile << longitude;
-    datafile << FDMExec->GetRotation()->Getphi();
-    datafile << FDMExec->GetRotation()->Gettht();
-    datafile << FDMExec->GetRotation()->Getpsi();
-    datafile << h;
+    datafile << Translation->GetUVW(eU);
+    datafile << Translation->GetUVW(eV);
+    datafile << Translation->GetUVW(eW);
+    datafile << Position->GetLatitude();
+    datafile << Position->GetLongitude();
+    datafile << Rotation->GetEuler(ePhi);
+    datafile << Rotation->GetEuler(eTht);
+    datafile << Rotation->GetEuler(ePsi);
+    datafile << Position->Geth();
     datafile.close();
     return true;
   } else {
@@ -220,77 +627,273 @@ bool FGState::StoreData(string fname)
   }
 }
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-bool FGState::DumpData(string fname)
-{
-  ofstream datafile(fname.c_str());
+void FGState::InitMatrices(double phi, double tht, double psi) {
+  double thtd2, psid2, phid2;
+  double Sthtd2, Spsid2, Sphid2;
+  double Cthtd2, Cpsid2, Cphid2;
+  double Cphid2Cthtd2;
+  double Cphid2Sthtd2;
+  double Sphid2Sthtd2;
+  double Sphid2Cthtd2;
 
-  if (datafile) {
-    datafile << "U: " << FDMExec->GetTranslation()->GetU() << endl;
-    datafile << "V: " << FDMExec->GetTranslation()->GetV() << endl;
-    datafile << "W: " << FDMExec->GetTranslation()->GetW() << endl;
-    datafile << "P: " << FDMExec->GetRotation()->GetP() << endl;
-    datafile << "Q: " << FDMExec->GetRotation()->GetQ() << endl;
-    datafile << "R: " << FDMExec->GetRotation()->GetR() << endl;
-    datafile << "L: " << FDMExec->GetAircraft()->GetL() << endl;
-    datafile << "M: " << FDMExec->GetAircraft()->GetM() << endl;
-    datafile << "N: " << FDMExec->GetAircraft()->GetN() << endl;
-    datafile << "latitude: " << latitude << endl;
-    datafile << "longitude: " << longitude << endl;
-    datafile << "alpha: " << FDMExec->GetTranslation()->Getalpha() << endl;
-    datafile << "beta: " << FDMExec->GetTranslation()->Getbeta() << endl;
-    datafile << "gamma: " << FDMExec->GetTranslation()->Getgamma() << endl;
-    datafile << "phi: " << FDMExec->GetRotation()->Getphi() << endl;
-    datafile << "tht: " << FDMExec->GetRotation()->Gettht() << endl;
-    datafile << "psi: " << FDMExec->GetRotation()->Getpsi() << endl;
-    datafile << "Pdot: " << FDMExec->GetRotation()->GetPdot() << endl;
-    datafile << "Qdot: " << FDMExec->GetRotation()->GetQdot() << endl;
-    datafile << "Rdot: " << FDMExec->GetRotation()->GetRdot() << endl;
-    datafile << "h: " << h << endl;
-    datafile << "a: " << a << endl;
-    datafile << "rho: " << FDMExec->GetAtmosphere()->Getrho() << endl;
-    datafile << "qbar: " << qbar << endl;
-    datafile << "sim_time: " << sim_time << endl;
-    datafile << "dt: " << dt << endl;
-    datafile << "m: " << FDMExec->GetAircraft()->GetMass() << endl;
-    datafile.close();
-    return true;
-  } else {
-    return false;
-  }
+  thtd2 = tht/2.0;
+  psid2 = psi/2.0;
+  phid2 = phi/2.0;
+
+  Sthtd2 = sin(thtd2);
+  Spsid2 = sin(psid2);
+  Sphid2 = sin(phid2);
+
+  Cthtd2 = cos(thtd2);
+  Cpsid2 = cos(psid2);
+  Cphid2 = cos(phid2);
+
+  Cphid2Cthtd2 = Cphid2*Cthtd2;
+  Cphid2Sthtd2 = Cphid2*Sthtd2;
+  Sphid2Sthtd2 = Sphid2*Sthtd2;
+  Sphid2Cthtd2 = Sphid2*Cthtd2;
+
+  vQtrn(1) = Cphid2Cthtd2*Cpsid2 + Sphid2Sthtd2*Spsid2;
+  vQtrn(2) = Sphid2Cthtd2*Cpsid2 - Cphid2Sthtd2*Spsid2;
+  vQtrn(3) = Cphid2Sthtd2*Cpsid2 + Sphid2Cthtd2*Spsid2;
+  vQtrn(4) = Cphid2Cthtd2*Spsid2 - Sphid2Sthtd2*Cpsid2;
+
+  CalcMatrices();
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGState::CalcMatrices(void) {
+  double Q0Q0, Q1Q1, Q2Q2, Q3Q3;
+  double Q0Q1, Q0Q2, Q0Q3, Q1Q2;
+  double Q1Q3, Q2Q3;
+
+  Q0Q0 = vQtrn(1)*vQtrn(1);
+  Q1Q1 = vQtrn(2)*vQtrn(2);
+  Q2Q2 = vQtrn(3)*vQtrn(3);
+  Q3Q3 = vQtrn(4)*vQtrn(4);
+  Q0Q1 = vQtrn(1)*vQtrn(2);
+  Q0Q2 = vQtrn(1)*vQtrn(3);
+  Q0Q3 = vQtrn(1)*vQtrn(4);
+  Q1Q2 = vQtrn(2)*vQtrn(3);
+  Q1Q3 = vQtrn(2)*vQtrn(4);
+  Q2Q3 = vQtrn(3)*vQtrn(4);
+
+  mTl2b(1,1) = Q0Q0 + Q1Q1 - Q2Q2 - Q3Q3;
+  mTl2b(1,2) = 2*(Q1Q2 + Q0Q3);
+  mTl2b(1,3) = 2*(Q1Q3 - Q0Q2);
+  mTl2b(2,1) = 2*(Q1Q2 - Q0Q3);
+  mTl2b(2,2) = Q0Q0 - Q1Q1 + Q2Q2 - Q3Q3;
+  mTl2b(2,3) = 2*(Q2Q3 + Q0Q1);
+  mTl2b(3,1) = 2*(Q1Q3 + Q0Q2);
+  mTl2b(3,2) = 2*(Q2Q3 - Q0Q1);
+  mTl2b(3,3) = Q0Q0 - Q1Q1 - Q2Q2 + Q3Q3;
+
+  mTb2l = mTl2b;
+  mTb2l.T();
 }
 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGState::IntegrateQuat(FGColumnVector3 vPQR, int rate) {
+  vQdot(1) = -0.5*(vQtrn(2)*vPQR(eP) + vQtrn(3)*vPQR(eQ) + vQtrn(4)*vPQR(eR));
+  vQdot(2) =  0.5*(vQtrn(1)*vPQR(eP) + vQtrn(3)*vPQR(eR) - vQtrn(4)*vPQR(eQ));
+  vQdot(3) =  0.5*(vQtrn(1)*vPQR(eQ) + vQtrn(4)*vPQR(eP) - vQtrn(2)*vPQR(eR));
+  vQdot(4) =  0.5*(vQtrn(1)*vPQR(eR) + vQtrn(2)*vPQR(eQ) - vQtrn(3)*vPQR(eP));
+  vQtrn += 0.5*dt*rate*(vlastQdot + vQdot);
+
+  vQtrn.Normalize();
+
+  vlastQdot = vQdot;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGColumnVector3& FGState::CalcEuler(void) {
+  if (mTl2b(3,3) == 0.0) mTl2b(3,3) = 0.0000001;
+  if (mTl2b(1,1) == 0.0) mTl2b(1,1) = 0.0000001;
 
-bool FGState::DisplayData(void)
+  vEuler(ePhi) = atan2(mTl2b(2,3), mTl2b(3,3));
+  vEuler(eTht) = asin(-mTl2b(1,3));
+  vEuler(ePsi) = atan2(mTl2b(1,2), mTl2b(1,1));
+
+  if (vEuler(ePsi) < 0.0) vEuler(ePsi) += 2*M_PI;
+
+  return vEuler;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGMatrix33& FGState::GetTs2b(void)
+{
+  double ca, cb, sa, sb;
+
+  double alpha = Translation->Getalpha();
+  double beta  = Translation->Getbeta();
+
+  ca = cos(alpha);
+  sa = sin(alpha);
+  cb = cos(beta);
+  sb = sin(beta);
+
+  mTs2b(1,1) = ca*cb;
+  mTs2b(1,2) = -ca*sb;
+  mTs2b(1,3) = -sa;
+  mTs2b(2,1) = sb;
+  mTs2b(2,2) = cb;
+  mTs2b(2,3) = 0.0;
+  mTs2b(3,1) = sa*cb;
+  mTs2b(3,2) = -sa*sb;
+  mTs2b(3,3) = ca;
+
+  return mTs2b;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGMatrix33& FGState::GetTb2s(void)
 {
-  cout << "U: " << FDMExec->GetTranslation()->GetU() << endl;
-  cout << "V: " << FDMExec->GetTranslation()->GetV() << endl;
-  cout << "W: " << FDMExec->GetTranslation()->GetW() << endl;
-  cout << "P: " << FDMExec->GetRotation()->GetP()*RADTODEG << endl;
-  cout << "Q: " << FDMExec->GetRotation()->GetQ()*RADTODEG << endl;
-  cout << "R: " << FDMExec->GetRotation()->GetR()*RADTODEG << endl;
-  cout << "L: " << FDMExec->GetAircraft()->GetL() << endl;
-  cout << "M: " << FDMExec->GetAircraft()->GetM() << endl;
-  cout << "N: " << FDMExec->GetAircraft()->GetN() << endl;
-  cout << "Vt: " << Vt << endl;
-  cout << "latitude: " << latitude << endl;
-  cout << "longitude: " << longitude << endl;
-  cout << "alpha: " << FDMExec->GetTranslation()->Getalpha()*RADTODEG << endl;
-  cout << "beta: " << FDMExec->GetTranslation()->Getbeta()*RADTODEG << endl;
-  cout << "gamma: " << FDMExec->GetTranslation()->Getgamma()*RADTODEG << endl;
-  cout << "phi: " << FDMExec->GetRotation()->Getphi()*RADTODEG << endl;
-  cout << "tht: " << FDMExec->GetRotation()->Gettht()*RADTODEG << endl;
-  cout << "psi: " << FDMExec->GetRotation()->Getpsi()*RADTODEG << endl;
-  cout << "Pdot: " << FDMExec->GetRotation()->GetPdot()*RADTODEG << endl;
-  cout << "Qdot: " << FDMExec->GetRotation()->GetQdot()*RADTODEG << endl;
-  cout << "Rdot: " << FDMExec->GetRotation()->GetRdot()*RADTODEG << endl;
-  cout << "h: " << h << endl;
-  cout << "a: " << a << endl;
-  cout << "rho: " << FDMExec->GetAtmosphere()->Getrho() << endl;
-  cout << "qbar: " << qbar << endl;
-  cout << "sim_time: " << sim_time << endl;
-  cout << "dt: " << dt << endl;
-  cout << "m: " << FDMExec->GetAircraft()->GetMass() << endl;
+  float alpha,beta;
+  float ca, cb, sa, sb;
+  
+  alpha = Translation->Getalpha();
+  beta  = Translation->Getbeta();
+  
+  ca = cos(alpha);
+  sa = sin(alpha);
+  cb = cos(beta);
+  sb = sin(beta);
+
+  mTb2s(1,1) = ca*cb;
+  mTb2s(1,2) = sb;
+  mTb2s(1,3) = sa*cb;
+  mTb2s(2,1) = -ca*sb;
+  mTb2s(2,2) = cb;
+  mTb2s(2,3) = -sa*sb;
+  mTb2s(3,1) = -sa;
+  mTb2s(3,2) = 0.0;
+  mTb2s(3,3) = ca;
+
+  return mTb2s;
+}
 
-  return true;
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+void FGState::ReportState(void) {
+  char out[80], flap[10], gear[12];
+  
+  cout << endl << "  JSBSim State" << endl;
+  snprintf(out,80,"    Weight: %7.0f lbs.  CG: %5.1f, %5.1f, %5.1f inches\n",
+                   FDMExec->GetMassBalance()->GetWeight(),
+                   FDMExec->GetMassBalance()->GetXYZcg(1),
+                   FDMExec->GetMassBalance()->GetXYZcg(2),
+                   FDMExec->GetMassBalance()->GetXYZcg(3));
+  cout << out;             
+  if( FCS->GetDfPos() <= 0.01)
+    snprintf(flap,10,"Up");
+  else
+    snprintf(flap,10,"%2.0f",FCS->GetDfPos());
+  if(FCS->GetGearPos() < 0.01)
+    snprintf(gear,12,"Up");
+  else if(FCS->GetGearPos() > 0.99)
+    snprintf(gear,12,"Down");
+  else
+    snprintf(gear,12,"In Transit");   
+  snprintf(out,80, "    Flaps: %3s  Gear: %12s\n",flap,gear);
+  cout << out;
+  snprintf(out,80, "    Speed: %4.0f KCAS  Mach: %5.2f\n",
+                    FDMExec->GetAuxiliary()->GetVcalibratedKTS(),
+                    GetParameter(FG_MACH) );
+  cout << out;
+  snprintf(out,80, "    Altitude: %7.0f ft.  AGL Altitude: %7.0f ft.\n",
+                    Position->Geth(),
+                    Position->GetDistanceAGL() );
+  cout << out;
+  snprintf(out,80, "    Angle of Attack: %6.2f deg  Pitch Angle: %6.2f deg\n",
+                    GetParameter(FG_ALPHA)*radtodeg,
+                    Rotation->Gettht()*radtodeg );
+  cout << out;
+  snprintf(out,80, "    Flight Path Angle: %6.2f deg  Climb Rate: %5.0f ft/min\n",
+                    Position->GetGamma()*radtodeg,
+                    Position->Gethdot()*60 );
+  cout << out;                  
+  snprintf(out,80, "    Normal Load Factor: %4.2f g's  Pitch Rate: %5.2f deg/s\n",
+                    Aircraft->GetNlf(),
+                    GetParameter(FG_PITCHRATE)*radtodeg );
+  cout << out;
+  snprintf(out,80, "    Heading: %3.0f deg true  Sideslip: %5.2f deg\n",
+                    Rotation->Getpsi()*radtodeg,
+                    GetParameter(FG_BETA)*radtodeg );                  
+  cout << out;
+  snprintf(out,80, "    Bank Angle: %5.2f deg\n",
+                    Rotation->Getphi()*radtodeg );
+  cout << out;
+  snprintf(out,80, "    Elevator: %5.2f deg  Left Aileron: %5.2f deg  Rudder: %5.2f deg\n",
+                    GetParameter(FG_ELEVATOR_POS)*radtodeg,
+                    GetParameter(FG_AILERON_POS)*radtodeg,
+                    GetParameter(FG_RUDDER_POS)*radtodeg );
+  cout << out;                  
+  snprintf(out,80, "    Throttle: %5.2f%c\n",
+                    FCS->GetThrottlePos(0)*100,'%' );
+  cout << out;
+  
+  snprintf(out,80, "    Wind Components: %5.2f kts head wind, %5.2f kts cross wind\n",
+                    FDMExec->GetAuxiliary()->GetHeadWind()*fpstokts,
+                    FDMExec->GetAuxiliary()->GetCrossWind()*fpstokts );
+  cout << out; 
+  
+  snprintf(out,80, "    Ground Speed: %4.0f knots , Ground Track: %3.0f deg true\n",
+                    Position->GetVground()*fpstokts,
+                    Position->GetGroundTrack()*radtodeg );
+  cout << out;                                   
+
+} 
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+//    The bitmasked value choices are as follows:
+//    unset: In this case (the default) JSBSim would only print
+//       out the normally expected messages, essentially echoing
+//       the config files as they are read. If the environment
+//       variable is not set, debug_lvl is set to 1 internally
+//    0: This requests JSBSim not to output any messages
+//       whatsoever.
+//    1: This value explicity requests the normal JSBSim
+//       startup messages
+//    2: This value asks for a message to be printed out when
+//       a class is instantiated
+//    4: When this value is set, a message is displayed when a
+//       FGModel object executes its Run() method
+//    8: When this value is set, various runtime state variables
+//       are printed out periodically
+//    16: When set various parameters are sanity checked and
+//       a message is printed out when they go out of bounds
+
+void FGState::Debug(int from)
+{
+  if (debug_lvl <= 0) return;
+
+  if (debug_lvl & 1) { // Standard console startup message output
+    if (from == 0) { // Constructor
+
+    }
+  }
+  if (debug_lvl & 2 ) { // Instantiation/Destruction notification
+    if (from == 0) cout << "Instantiated: FGState" << endl;
+    if (from == 1) cout << "Destroyed:    FGState" << endl;
+  }
+  if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
+  }
+  if (debug_lvl & 8 ) { // Runtime state variables
+  }
+  if (debug_lvl & 16) { // Sanity checking
+  }
+  if (debug_lvl & 64) {
+    if (from == 0) { // Constructor
+      cout << IdSrc << endl;
+      cout << IdHdr << endl;
+    }
+  }
 }
+
+