flightgear/src/FDM/JSBSim/FGFDMExec.cpp

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 Module:       FGFDMExec.cpp
 Author:       Jon S. Berndt
 Date started: 11/17/98
 Purpose:      Schedules and runs the model routines.

 ------------- Copyright (C) 1999  Jon S. Berndt (jon@jsbsim.org) -------------

 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser 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 Lesser General Public License for more
 details.

 You should have received a copy of the GNU Lesser 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 Lesser General Public License can also be found on
 the world wide web at http://www.gnu.org.

FUNCTIONAL DESCRIPTION
--------------------------------------------------------------------------------

This class wraps up the simulation scheduling routines.

HISTORY
--------------------------------------------------------------------------------
11/17/98   JSB   Created

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
COMMENTS, REFERENCES,  and NOTES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/

#include "FGFDMExec.h"
#include "models/FGAtmosphere.h"
#include "models/atmosphere/FGMSIS.h"
#include "models/atmosphere/FGMars.h"
#include "models/FGFCS.h"
#include "models/FGPropulsion.h"
#include "models/FGMassBalance.h"
#include "models/FGGroundReactions.h"
#include "models/FGExternalReactions.h"
#include "models/FGBuoyantForces.h"
#include "models/FGAerodynamics.h"
#include "models/FGInertial.h"
#include "models/FGAircraft.h"
#include "models/FGPropagate.h"
#include "models/FGAuxiliary.h"
#include "models/FGInput.h"
#include "models/FGOutput.h"
#include "initialization/FGInitialCondition.h"
//#include "initialization/FGTrimAnalysis.h" // Remove until later
#include "input_output/FGPropertyManager.h"
#include "input_output/FGScript.h"

#include <iostream>
#include <iterator>
#include <cstdlib>

using namespace std;

namespace JSBSim {

static const char *IdSrc = "$Id: FGFDMExec.cpp,v 1.82 2010/10/07 03:17:29 jberndt Exp $";
static const char *IdHdr = ID_FDMEXEC;

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/

void checkTied ( FGPropertyManager *node )
{
  int N = node->nChildren();
  string name;

  for (int i=0; i<N; i++) {
    if (node->getChild(i)->nChildren() ) {
      checkTied( (FGPropertyManager*)node->getChild(i) );
    }
    if ( node->getChild(i)->isTied() ) {
      name = ((FGPropertyManager*)node->getChild(i))->GetFullyQualifiedName();
      node->Untie(name);
    }
  }
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// Constructors
FGFDMExec::FGFDMExec(FGPropertyManager* root) : Root(root)
{
  FDMctr = new unsigned int;
  *FDMctr = 0;
  Initialize();
}

FGFDMExec::FGFDMExec(FGPropertyManager* root, unsigned int* fdmctr) : Root(root), FDMctr(fdmctr)
{
  Initialize();
}

void FGFDMExec::Initialize()
{
  Frame           = 0;
  Error           = 0;
  GroundCallback  = 0;
  Atmosphere      = 0;
  FCS             = 0;
  Propulsion      = 0;
  MassBalance     = 0;
  Aerodynamics    = 0;
  Inertial        = 0;
  GroundReactions = 0;
  ExternalReactions = 0;
  BuoyantForces   = 0;
  Aircraft        = 0;
  Propagate       = 0;
  Auxiliary       = 0;
  Input           = 0;
  IC              = 0;
  Trim            = 0;
  Script          = 0;

  RootDir = "";

  modelLoaded = false;
  IsChild = false;
  holding = false;
  Terminate = false;

  sim_time = 0.0;
  dT = 1.0/120.0; // a default timestep size. This is needed for when JSBSim is
                  // run in standalone mode with no initialization file.

  try {
    char* num = getenv("JSBSIM_DEBUG");
    if (num) debug_lvl = atoi(num); // set debug level
  } catch (...) {                   // if error set to 1
    debug_lvl = 1;
  }

  if (Root == 0) {                 // Then this is the root FDM
    Root = new FGPropertyManager;  // Create the property manager
    
    FDMctr = new unsigned int;     // Create and initialize the child FDM counter
    (*FDMctr) = 0;
  }

  // Store this FDM's ID
  IdFDM = (*FDMctr); // The main (parent) JSBSim instance is always the "zeroth"
                                                                      
  // Prepare FDMctr for the next child FDM id
  (*FDMctr)++;       // instance. "child" instances are loaded last.

  instance = Root->GetNode("/fdm/jsbsim",IdFDM,true);
  Debug(0);
  // this is to catch errors in binding member functions to the property tree.
  try {
    Allocate();
  } catch ( string msg ) {
    cout << "Caught error: " << msg << endl;
    exit(1);
  }

  trim_status = false;
  ta_mode     = 99;

  Constructing = true;
  typedef int (FGFDMExec::*iPMF)(void) const;
//  instance->Tie("simulation/do_trim_analysis", this, (iPMF)0, &FGFDMExec::DoTrimAnalysis);
  instance->Tie("simulation/do_simple_trim", this, (iPMF)0, &FGFDMExec::DoTrim);
  instance->Tie("simulation/reset", this, (iPMF)0, &FGFDMExec::ResetToInitialConditions);
  instance->Tie("simulation/terminate", (int *)&Terminate);
  instance->Tie("simulation/sim-time-sec", this, &FGFDMExec::GetSimTime);
  instance->Tie("simulation/jsbsim-debug", this, &FGFDMExec::GetDebugLevel, &FGFDMExec::SetDebugLevel);

  Constructing = false;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

FGFDMExec::~FGFDMExec()
{
  try {
    checkTied( instance );
    DeAllocate();
    
    if (IdFDM == 0) { // Meaning this is no child FDM
      if(Root != 0) {
         delete Root;
         Root = 0;
      }
      if(FDMctr != 0) {
         delete FDMctr;
         FDMctr = 0;
      }
    }
  } catch ( string msg ) {
    cout << "Caught error: " << msg << endl;
  }

  for (unsigned int i=1; i<ChildFDMList.size(); i++) delete ChildFDMList[i]->exec;
  ChildFDMList.clear();

  PropertyCatalog.clear();

  FDMctr--;

  Debug(1);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::Allocate(void)
{
  bool result=true;

  Atmosphere      = new FGAtmosphere(this);
  FCS             = new FGFCS(this);
  Propulsion      = new FGPropulsion(this);
  MassBalance     = new FGMassBalance(this);
  Aerodynamics    = new FGAerodynamics (this);
  Inertial        = new FGInertial(this);

  GroundCallback  = new FGGroundCallback(Inertial->GetRefRadius());

  GroundReactions = new FGGroundReactions(this);
  ExternalReactions = new FGExternalReactions(this);
  BuoyantForces   = new FGBuoyantForces(this);
  Aircraft        = new FGAircraft(this);
  Propagate       = new FGPropagate(this);
  Auxiliary       = new FGAuxiliary(this);
  Input           = new FGInput(this);

  // Schedule a model. The second arg (the integer) is the pass number. For
  // instance, the atmosphere model could get executed every fifth pass it is called.
  
  Schedule(Input,           1);
  Schedule(Atmosphere,      1);
  Schedule(FCS,             1);
  Schedule(Propulsion,      1);
  Schedule(MassBalance,     1);
  Schedule(Aerodynamics,    1);
  Schedule(Inertial,        1);
  Schedule(GroundReactions, 1);
  Schedule(ExternalReactions, 1);
  Schedule(BuoyantForces,   1);
  Schedule(Aircraft,        1);
  Schedule(Propagate,       1);
  Schedule(Auxiliary,       1);

  // Initialize models so they can communicate with each other

  vector <FGModel*>::iterator it;
  for (it = Models.begin(); it != Models.end(); ++it) (*it)->InitModel();

  IC = new FGInitialCondition(this);

  modelLoaded = false;

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::DeAllocate(void)
{
  delete Input;
  delete Atmosphere;
  delete FCS;
  delete Propulsion;
  delete MassBalance;
  delete Aerodynamics;
  delete Inertial;
  delete GroundReactions;
  delete ExternalReactions;
  delete BuoyantForces;
  delete Aircraft;
  delete Propagate;
  delete Auxiliary;
  delete Script;

  for (unsigned i=0; i<Outputs.size(); i++) delete Outputs[i];
  Outputs.clear();

  delete IC;
  delete Trim;

  delete GroundCallback;

  Error       = 0;

  Input           = 0;
  Atmosphere      = 0;
  FCS             = 0;
  Propulsion      = 0;
  MassBalance     = 0;
  Aerodynamics    = 0;
  Inertial        = 0;
  GroundReactions = 0;
  ExternalReactions = 0;
  BuoyantForces   = 0;
  Aircraft        = 0;
  Propagate       = 0;
  Auxiliary       = 0;
  Script          = 0;

  Models.clear();

  modelLoaded = false;
  return modelLoaded;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::Schedule(FGModel* model, int rate)
{
  model->SetRate(rate);
  Models.push_back(model);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::Run(void)
{
  bool success=true;

  Debug(2);

  for (unsigned int i=1; i<ChildFDMList.size(); i++) {
    ChildFDMList[i]->AssignState(Propagate); // Transfer state to the child FDM
    ChildFDMList[i]->Run();
  }

  // returns true if success, false if complete
  if (Script != 0 && !IntegrationSuspended()) success = Script->RunScript();

  vector <FGModel*>::iterator it;
  for (it = Models.begin(); it != Models.end(); ++it) (*it)->Run();

  Frame++;
  if (!Holding()) IncrTime();
  if (Terminate) success = false;

  return (success);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// This call will cause the sim time to reset to 0.0

bool FGFDMExec::RunIC(void)
{
  SuspendIntegration(); // saves the integration rate, dt, then sets it to 0.0.
  Initialize(IC);
  Run();
  ResumeIntegration(); // Restores the integration rate to what it was.

  return true;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::Initialize(FGInitialCondition *FGIC)
{
  Propagate->SetInitialState( FGIC );

  Atmosphere->Run();
  Atmosphere->SetWindNED( FGIC->GetWindNFpsIC(),
                          FGIC->GetWindEFpsIC(),
                          FGIC->GetWindDFpsIC() );

  FGColumnVector3 vAeroUVW;
  vAeroUVW = Propagate->GetUVW() + Propagate->GetTl2b()*Atmosphere->GetTotalWindNED();

  double alpha, beta;
  if (vAeroUVW(eW) != 0.0)
    alpha = vAeroUVW(eU)*vAeroUVW(eU) > 0.0 ? atan2(vAeroUVW(eW), vAeroUVW(eU)) : 0.0;
  else
    alpha = 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;

  Auxiliary->SetAB(alpha, beta);

  double Vt = vAeroUVW.Magnitude();
  Auxiliary->SetVt(Vt);

  Auxiliary->SetMach(Vt/Atmosphere->GetSoundSpeed());

  double qbar = 0.5*Vt*Vt*Atmosphere->GetDensity();
  Auxiliary->Setqbar(qbar);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// A private, internal function call for Tie-ing to a property, so it needs an
// argument.

void FGFDMExec::ResetToInitialConditions(int mode)
{
  if (mode == 1) {
    for (unsigned int i=0; i<Outputs.size(); i++) {
      Outputs[i]->SetStartNewFile(true); 
    }
  }
  
  ResetToInitialConditions();
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::ResetToInitialConditions(void)
{
  if (Constructing) return;

  vector <FGModel*>::iterator it;
  for (it = Models.begin(); it != Models.end(); ++it) (*it)->InitModel();

  RunIC();
  if (Script) Script->ResetEvents();
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::SetGroundCallback(FGGroundCallback* p)
{
  delete GroundCallback;
  GroundCallback = p;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

vector <string> FGFDMExec::EnumerateFDMs(void)
{
  vector <string> FDMList;

  FDMList.push_back(Aircraft->GetAircraftName());

  for (unsigned int i=1; i<ChildFDMList.size(); i++) {
    FDMList.push_back(ChildFDMList[i]->exec->GetAircraft()->GetAircraftName());
  }

  return FDMList;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::LoadScript(const string& script, double deltaT)
{
  bool result;

  Script = new FGScript(this);
  result = Script->LoadScript(RootDir + script, deltaT);

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::LoadModel(const string& AircraftPath, const string& EnginePath, const string& SystemsPath,
                const string& model, bool addModelToPath)
{
  FGFDMExec::AircraftPath = RootDir + AircraftPath;
  FGFDMExec::EnginePath = RootDir + EnginePath;
  FGFDMExec::SystemsPath = RootDir + SystemsPath;

  return LoadModel(model, addModelToPath);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::LoadModel(const string& model, bool addModelToPath)
{
  string token;
  string aircraftCfgFileName;
  Element* element = 0L;
  bool result = false; // initialize result to false, indicating input file not yet read

  modelName = model; // Set the class modelName attribute

  if( AircraftPath.empty() || EnginePath.empty() || SystemsPath.empty()) {
    cerr << "Error: attempted to load aircraft with undefined ";
    cerr << "aircraft, engine, and system paths" << endl;
    return false;
  }

  FullAircraftPath = AircraftPath;
  if (addModelToPath) FullAircraftPath += "/" + model;
  aircraftCfgFileName = FullAircraftPath + "/" + model + ".xml";

  if (modelLoaded) {
    DeAllocate();
    Allocate();
  }

  int saved_debug_lvl = debug_lvl;

  document = LoadXMLDocument(aircraftCfgFileName); // "document" is a class member
  if (document) {
    if (IsChild) debug_lvl = 0;

    ReadPrologue(document);

    if (IsChild) debug_lvl = saved_debug_lvl;

    // Process the fileheader element in the aircraft config file. This element is OPTIONAL.
    element = document->FindElement("fileheader");
    if (element) {
      result = ReadFileHeader(element);
      if (!result) {
        cerr << endl << "Aircraft fileheader element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    if (IsChild) debug_lvl = 0;

    // Process the metrics element. This element is REQUIRED.
    element = document->FindElement("metrics");
    if (element) {
      result = Aircraft->Load(element);
      if (!result) {
        cerr << endl << "Aircraft metrics element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    } else {
      cerr << endl << "No metrics element was found in the aircraft config file." << endl;
      return false;
    }

    // Process the mass_balance element. This element is REQUIRED.
    element = document->FindElement("mass_balance");
    if (element) {
      result = MassBalance->Load(element);
      if (!result) {
        cerr << endl << "Aircraft mass_balance element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    } else {
      cerr << endl << "No mass_balance element was found in the aircraft config file." << endl;
      return false;
    }

    // Process the ground_reactions element. This element is REQUIRED.
    element = document->FindElement("ground_reactions");
    if (element) {
      result = GroundReactions->Load(element);
      if (!result) {
        cerr << endl << "Aircraft ground_reactions element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    } else {
      cerr << endl << "No ground_reactions element was found in the aircraft config file." << endl;
      return false;
    }

    // Process the external_reactions element. This element is OPTIONAL.
    element = document->FindElement("external_reactions");
    if (element) {
      result = ExternalReactions->Load(element);
      if (!result) {
        cerr << endl << "Aircraft external_reactions element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the buoyant_forces element. This element is OPTIONAL.
    element = document->FindElement("buoyant_forces");
    if (element) {
      result = BuoyantForces->Load(element);
      if (!result) {
        cerr << endl << "Aircraft buoyant_forces element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the propulsion element. This element is OPTIONAL.
    element = document->FindElement("propulsion");
    if (element) {
      result = Propulsion->Load(element);
      if (!result) {
        cerr << endl << "Aircraft propulsion element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the system element[s]. This element is OPTIONAL, and there may be more than one.
    element = document->FindElement("system");
    while (element) {
      result = FCS->Load(element, FGFCS::stSystem);
      if (!result) {
        cerr << endl << "Aircraft system element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
      element = document->FindNextElement("system");
    }

    // Process the autopilot element. This element is OPTIONAL.
    element = document->FindElement("autopilot");
    if (element) {
      result = FCS->Load(element, FGFCS::stAutoPilot);
      if (!result) {
        cerr << endl << "Aircraft autopilot element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the flight_control element. This element is OPTIONAL.
    element = document->FindElement("flight_control");
    if (element) {
      result = FCS->Load(element, FGFCS::stFCS);
      if (!result) {
        cerr << endl << "Aircraft flight_control element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the aerodynamics element. This element is OPTIONAL, but almost always expected.
    element = document->FindElement("aerodynamics");
    if (element) {
      result = Aerodynamics->Load(element);
      if (!result) {
        cerr << endl << "Aircraft aerodynamics element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    } else {
      cerr << endl << "No expected aerodynamics element was found in the aircraft config file." << endl;
    }

    // Process the input element. This element is OPTIONAL.
    element = document->FindElement("input");
    if (element) {
      result = Input->Load(element);
      if (!result) {
        cerr << endl << "Aircraft input element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    // Process the output element[s]. This element is OPTIONAL, and there may be more than one.
    unsigned int idx=0;
    typedef int (FGOutput::*iOPMF)(void) const;
    element = document->FindElement("output");
    while (element) {
      if (debug_lvl > 0) cout << endl << "  Output data set: " << idx << "  ";
      FGOutput* Output = new FGOutput(this);
      Output->InitModel();
      Schedule(Output, 1);
      result = Output->Load(element);
      if (!result) {
        cerr << endl << "Aircraft output element has problems in file " << aircraftCfgFileName << endl;
        return result;
      } else {
        Outputs.push_back(Output);
        string outputProp = CreateIndexedPropertyName("simulation/output",idx);
        instance->Tie(outputProp+"/log_rate_hz", Output, (iOPMF)0, &FGOutput::SetRate);
        idx++;
      }
      element = document->FindNextElement("output");
    }

    // Lastly, process the child element. This element is OPTIONAL - and NOT YET SUPPORTED.
    element = document->FindElement("child");
    if (element) {
      result = ReadChild(element);
      if (!result) {
        cerr << endl << "Aircraft child element has problems in file " << aircraftCfgFileName << endl;
        return result;
      }
    }

    modelLoaded = true;

    if (debug_lvl > 0) {
      MassBalance->Run(); // Update all mass properties for the report.
      MassBalance->GetMassPropertiesReport();

      cout << endl << fgblue << highint
           << "End of vehicle configuration loading." << endl
           << "-------------------------------------------------------------------------------"
           << reset << endl;
    }
    
    if (IsChild) debug_lvl = saved_debug_lvl;

  } else {
    cerr << fgred
         << "  JSBSim failed to open the configuration file: " << aircraftCfgFileName
         << fgdef << endl;
  }

  // Late bind previously undefined FCS inputs.
  try {
    FCS->LateBind();
  } catch (string prop) {
    cerr << endl << fgred << "  Could not late bind property " << prop 
         << ". Aborting." << endl;
    result = false;
  }

  if (result) {
    struct PropertyCatalogStructure masterPCS;
    masterPCS.base_string = "";
    masterPCS.node = (FGPropertyManager*)Root;
    BuildPropertyCatalog(&masterPCS);
  }

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::BuildPropertyCatalog(struct PropertyCatalogStructure* pcs)
{
  struct PropertyCatalogStructure* pcsNew = new struct PropertyCatalogStructure;
  int node_idx = 0;

  for (int i=0; i<pcs->node->nChildren(); i++) {
    pcsNew->base_string = pcs->base_string + "/" + pcs->node->getChild(i)->getName();
    node_idx = pcs->node->getChild(i)->getIndex();
    if (node_idx != 0) {
      pcsNew->base_string = CreateIndexedPropertyName(pcsNew->base_string, node_idx);
    }
    if (pcs->node->getChild(i)->nChildren() == 0) {
      if (pcsNew->base_string.substr(0,11) == string("/fdm/jsbsim")) {
        pcsNew->base_string = pcsNew->base_string.erase(0,12);
      }
      PropertyCatalog.push_back(pcsNew->base_string);
    } else {
      pcsNew->node = (FGPropertyManager*)pcs->node->getChild(i);
      BuildPropertyCatalog(pcsNew);
    }
  }
  delete pcsNew;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

string FGFDMExec::QueryPropertyCatalog(const string& in)
{
  string results="";
  for (unsigned i=0; i<PropertyCatalog.size(); i++) {
    if (PropertyCatalog[i].find(in) != string::npos) results += PropertyCatalog[i] + "\n";
  }
  if (results.empty()) return "No matches found\n";
  return results;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::PrintPropertyCatalog(void)
{
  cout << endl;
  cout << "  " << fgblue << highint << underon << "Property Catalog for "
       << modelName << reset << endl << endl;
  for (unsigned i=0; i<PropertyCatalog.size(); i++) {
    cout << "    " << PropertyCatalog[i] << endl;
  }
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::ReadFileHeader(Element* el)
{
  bool result = true; // true for success

  if (debug_lvl == 0) return result;

  if (IsChild) {
    cout << endl <<highint << fgblue << "Reading child model: " << IdFDM << reset << endl << endl;
  }

  if (el->FindElement("description"))
    cout << "  Description:   " << el->FindElement("description")->GetDataLine() << endl;
  if (el->FindElement("author"))
    cout << "  Model Author:  " << el->FindElement("author")->GetDataLine() << endl;
  if (el->FindElement("filecreationdate"))
    cout << "  Creation Date: " << el->FindElement("filecreationdate")->GetDataLine() << endl;
  if (el->FindElement("version"))
    cout << "  Version:       " << el->FindElement("version")->GetDataLine() << endl;

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::ReadPrologue(Element* el) // el for ReadPrologue is the document element
{
  bool result = true; // true for success

  if (!el) return false;

  string AircraftName = el->GetAttributeValue("name");
  Aircraft->SetAircraftName(AircraftName);

  if (debug_lvl & 1) cout << underon << "Reading Aircraft Configuration File"
            << underoff << ": " << highint << AircraftName << normint << endl;

  CFGVersion = el->GetAttributeValue("version");
  Release    = el->GetAttributeValue("release");

  if (debug_lvl & 1)
    cout << "                            Version: " << highint << CFGVersion
                                                    << normint << endl;
  if (CFGVersion != needed_cfg_version) {
    cerr << endl << fgred << "YOU HAVE AN INCOMPATIBLE CFG FILE FOR THIS AIRCRAFT."
            " RESULTS WILL BE UNPREDICTABLE !!" << endl;
    cerr << "Current version needed is: " << needed_cfg_version << endl;
    cerr << "         You have version: " << CFGVersion << endl << fgdef << endl;
    return false;
  }

  if (Release == "ALPHA" && (debug_lvl & 1)) {
    cout << endl << endl
         << highint << "This aircraft model is an " << fgred << Release
         << reset << highint << " release!!!" << endl << endl << reset
         << "This aircraft model may not even properly load, and probably"
         << " will not fly as expected." << endl << endl
         << fgred << highint << "Use this model for development purposes ONLY!!!"
         << normint << reset << endl << endl;
  } else if (Release == "BETA" && (debug_lvl & 1)) {
    cout << endl << endl
         << highint << "This aircraft model is a " << fgred << Release
         << reset << highint << " release!!!" << endl << endl << reset
         << "This aircraft model probably will not fly as expected." << endl << endl
         << fgblue << highint << "Use this model for development purposes ONLY!!!"
         << normint << reset << endl << endl;
  } else if (Release == "PRODUCTION" && (debug_lvl & 1)) {
    cout << endl << endl
         << highint << "This aircraft model is a " << fgblue << Release
         << reset << highint << " release." << endl << endl << reset;
  } else if (debug_lvl & 1) {
    cout << endl << endl
         << highint << "This aircraft model is an " << fgred << Release
         << reset << highint << " release!!!" << endl << endl << reset
         << "This aircraft model may not even properly load, and probably"
         << " will not fly as expected." << endl << endl
         << fgred << highint << "Use this model for development purposes ONLY!!!"
         << normint << reset << endl << endl;
  }

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::ReadChild(Element* el)
{
  // Add a new childData object to the child FDM list
  // Populate that childData element with a new FDMExec object
  // Set the IsChild flag for that FDMExec object
  // Get the aircraft name
  // set debug level to print out no additional data for child objects
  // Load the model given the aircraft name
  // reset debug level to prior setting

  string token;

  struct childData* child = new childData;

  child->exec = new FGFDMExec(Root, FDMctr);
  child->exec->SetChild(true);

  string childAircraft = el->GetAttributeValue("name");
  string sMated = el->GetAttributeValue("mated");
  if (sMated == "false") child->mated = false; // child objects are mated by default.
  string sInternal = el->GetAttributeValue("internal");
  if (sInternal == "true") child->internal = true; // child objects are external by default.

  child->exec->SetAircraftPath( AircraftPath );
  child->exec->SetEnginePath( EnginePath );
  child->exec->SetSystemsPath( SystemsPath );
  child->exec->LoadModel(childAircraft);

  Element* location = el->FindElement("location");
  if (location) {
    child->Loc = location->FindElementTripletConvertTo("IN");
  } else {
    cerr << endl << highint << fgred << "  No location was found for this child object!" << reset << endl;
    exit(-1);
  }
  
  Element* orientation = el->FindElement("orient");
  if (orientation) {
    child->Orient = orientation->FindElementTripletConvertTo("RAD");
  } else if (debug_lvl > 0) {
    cerr << endl << highint << "  No orientation was found for this child object! Assuming 0,0,0." << reset << endl;
  }

  ChildFDMList.push_back(child);

  return true;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

FGPropertyManager* FGFDMExec::GetPropertyManager(void)
{
  return instance;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

FGTrim* FGFDMExec::GetTrim(void)
{
  delete Trim;
  Trim = new FGTrim(this,tNone);
  return Trim;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::DisableOutput(void)
{
  for (unsigned i=0; i<Outputs.size(); i++) {
    Outputs[i]->Disable();
  }
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::EnableOutput(void)
{
  for (unsigned i=0; i<Outputs.size(); i++) {
    Outputs[i]->Enable();
  }
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGFDMExec::SetOutputDirectives(const string& fname)
{
  bool result;

  FGOutput* Output = new FGOutput(this);
  Output->SetDirectivesFile(RootDir + fname);
  Output->InitModel();
  Schedule(Output, 1);
  result = Output->Load(0);

  if (result) {
    Outputs.push_back(Output);
    typedef int (FGOutput::*iOPMF)(void) const;
    string outputProp = CreateIndexedPropertyName("simulation/output",Outputs.size()-1);
    instance->Tie(outputProp+"/log_rate_hz", Output, (iOPMF)0, &FGOutput::SetRate);
  }

  return result;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::DoTrim(int mode)
{
  double saved_time;

  if (Constructing) return;

  if (mode < 0 || mode > JSBSim::tNone) {
    cerr << endl << "Illegal trimming mode!" << endl << endl;
    return;
  }
  saved_time = sim_time;
  FGTrim trim(this, (JSBSim::TrimMode)mode);
  if ( !trim.DoTrim() ) cerr << endl << "Trim Failed" << endl << endl;
  trim.Report();
  sim_time = saved_time;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
/*
void FGFDMExec::DoTrimAnalysis(int mode)
{
  double saved_time;
  if (Constructing) return;

  if (mode < 0 || mode > JSBSim::taNone) {
    cerr << endl << "Illegal trimming mode!" << endl << endl;
    return;
  }
  saved_time = sim_time;

  FGTrimAnalysis trimAnalysis(this, (JSBSim::TrimAnalysisMode)mode);

  if ( !trimAnalysis.Load(IC->GetInitFile(), false) ) {
    cerr << "A problem occurred with trim configuration file " << trimAnalysis.Load(IC->GetInitFile()) << endl;
    exit(-1);
  }

  bool result = trimAnalysis.DoTrim();

  if ( !result ) cerr << endl << "Trim Failed" << endl << endl;

  trimAnalysis.Report();
  Setsim_time(saved_time);

  EnableOutput();
  cout << "\nOutput: " << GetOutputFileName() << endl;

}
*/
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::UseAtmosphereMSIS(void)
{
  FGAtmosphere *oldAtmosphere = Atmosphere;
  Atmosphere = new MSIS(this);
  if (!Atmosphere->InitModel()) {
    cerr << fgred << "MSIS Atmosphere model init failed" << fgdef << endl;
    Error+=1;
  }
  delete oldAtmosphere;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGFDMExec::UseAtmosphereMars(void)
{
/*
  FGAtmosphere *oldAtmosphere = Atmosphere;
  Atmosphere = new FGMars(this);
  if (!Atmosphere->InitModel()) {
    cerr << fgred << "Mars Atmosphere model init failed" << fgdef << endl;
    Error+=1;
  }
  delete oldAtmosphere;
*/
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//    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 FGFDMExec::Debug(int from)
{
  if (debug_lvl <= 0) return;

  if (debug_lvl & 1 && IdFDM == 0) { // Standard console startup message output
    if (from == 0) { // Constructor
      cout << "\n\n     " << highint << underon << "JSBSim Flight Dynamics Model v"
                                     << JSBSim_version << underoff << normint << endl;
      cout << halfint << "            [JSBSim-ML v" << needed_cfg_version << "]\n\n";
      cout << normint << "JSBSim startup beginning ...\n\n";
    } else if (from == 3) {
      cout << "\n\nJSBSim startup complete\n\n";
    }
  }
  if (debug_lvl & 2 ) { // Instantiation/Destruction notification
    if (from == 0) cout << "Instantiated: FGFDMExec" << endl;
    if (from == 1) cout << "Destroyed:    FGFDMExec" << endl;
  }
  if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
    if (from == 2) {
      cout << "================== Frame: " << Frame << "  Time: "
           << sim_time << " dt: " << dT << endl;
    }
  }
  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;
    }
  }
}
}