flightgear/src/Traffic/Schedule.cxx

/******************************************************************************
 * Schedule.cxx
 * Written by Durk Talsma, started May 5, 2004.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 *
 ****************************************************************************
 *
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <stdlib.h>
#include <time.h>
#include <iostream>
#include <fstream>


#include <string>
#include <vector>
#include <algorithm>

#include <plib/sg.h>

#include <simgear/compiler.h>
#include <simgear/math/polar3d.hxx>
#include <simgear/math/sg_geodesy.hxx>
#include <simgear/props/props.hxx>
#include <simgear/route/waypoint.hxx>
#include <simgear/structure/subsystem_mgr.hxx>
#include <simgear/xml/easyxml.hxx>

#include <AIModel/AIFlightPlan.hxx>
#include <AIModel/AIManager.hxx>
#include <AIModel/AIAircraft.hxx>
#include <Airports/simple.hxx>
#include <Main/fg_init.hxx>   // That's pretty ugly, but I need fgFindAirportID


#include "SchedFlight.hxx"
#include "TrafficMgr.hxx"

SG_USING_STD( sort );

/******************************************************************************
 * the FGAISchedule class contains data members and code to maintain a
 * schedule of Flights for an articically controlled aircraft. 
 *****************************************************************************/
FGAISchedule::FGAISchedule()
{
  firstRun     = true;
  AIManagerRef = 0;

  heavy = false;
  lat = 0;
  lon = 0;
  radius = 0;
  groundOffset = 0;
  distanceToUser = 0;
}

FGAISchedule::FGAISchedule(string    mdl, 
			   string    liv, 
			   string    reg, 
			   bool      hvy, 
			   string act, 
			   string arln, 
			   string mclass, 
			   string fltpe,
			   double rad,
			   double grnd,
			   FGScheduledFlightVec flt)
{
  modelPath    = mdl; 
  livery       = liv; 
  registration = reg;
  acType       = act;
  airline      = arln;
  m_class      = mclass;
  flightType   = fltpe;
  lat = 0;
  lon = 0;
  radius       = rad;
  groundOffset = grnd;
  distanceToUser = 0;
  heavy = hvy;
  for (FGScheduledFlightVecIterator i = flt.begin();
       i != flt.end();
       i++)
    flights.push_back(FGScheduledFlight((*i)));
  AIManagerRef = 0;
  firstRun = true;
}

FGAISchedule::FGAISchedule(const FGAISchedule &other)
{
  modelPath    = other.modelPath;
  livery       = other.livery;
  registration = other.registration;
  heavy        = other.heavy;
  flights      = other.flights;
  lat          = other.lat;
  lon          = other.lon;
  AIManagerRef = other.AIManagerRef;
  acType       = other.acType;
  airline      = other.airline;
  m_class      = other.m_class;
  firstRun     = other.firstRun;
  radius       = other.radius;
  groundOffset = other.groundOffset;
  flightType   = other.flightType;
  distanceToUser = other.distanceToUser;
}


FGAISchedule::~FGAISchedule()
{
  
} 

bool FGAISchedule::init()
{
  //tm targetTimeDate;
  //SGTime* currTimeDate = globals->get_time_params();

  //tm *temp = currTimeDate->getGmt();
  //char buffer[512];
  //sgTimeFormatTime(&targetTimeDate, buffer);
  //cout << "Scheduled Time " << buffer << endl; 
  //cout << "Time :" << time(NULL) << " SGTime : " << sgTimeGetGMT(temp) << endl;
  for (FGScheduledFlightVecIterator i = flights.begin(); 
       i != flights.end(); 
       i++)
    {
      //i->adjustTime(now);
      if (!(i->initializeAirports()))
	return false;
    } 
  //sort(flights.begin(), flights.end());
  // Since time isn't initialized yet when this function is called,
  // Find the closest possible airport.
  // This should give a reasonable initialization order. 
  setClosestDistanceToUser();
  return true;
}

bool FGAISchedule::update(time_t now)
{
  FGAirport *dep;
  FGAirport *arr;
  sgdVec3 a, b, cross;
  sgdVec3 newPos;
  sgdMat4 matrix;
  double angle;

  FGAIManager *aimgr;
  string airport;
  
  double courseToUser,   courseToDest;
  double distanceToDest;
  double speed;

  Point3D temp;
  time_t 
    totalTimeEnroute, 
    elapsedTimeEnroute,
    remainingTimeEnroute;
  double
    userLatitude,
    userLongitude;

  if (fgGetBool("/sim/traffic-manager/enabled") == false)
    return true;
  
  aimgr = (FGAIManager *) globals-> get_subsystem("ai_model");  
  // Before the flight status of this traffic entity is updated 
  // for the first time, we need to roll back it's flight schedule so
  // so that all the flights are centered around this simulated week's time
  // table. This is to avoid the situation where the first scheduled flight is
  // in the future, causing the traffic manager to not generate traffic until
  // simulated time has caught up with the real world time at initialization.
  // This is to counter a more general initialization bug, caused by the fact
  // that warp is not yet set when the  schedule is initialized. This is
  // especially a problem when using a negative time offset.
  // i.e let's say we specify FlightGear to run with --time-offset=-24:00:00. 
  // Then the schedule will initialize using today, but we will fly yesterday.
  // Thus, it would take a whole day of simulation before the traffic manager
  // finally kicks in. 
  if (firstRun)
    {
      for (FGScheduledFlightVecIterator i = flights.begin(); 
  	   i != flights.end(); 
  	   i++)
  	{
  	  i->adjustTime(now);
  	}
      firstRun = false;
    }
  
  // Sort all the scheduled flights according to scheduled departure time.
  // Because this is done at every update, we only need to check the status
  // of the first listed flight. 
  sort(flights.begin(), flights.end());
  FGScheduledFlightVecIterator i = flights.begin();
  if (AIManagerRef)
    {
      // Check if this aircraft has been released. 
      FGTrafficManager *tmgr = (FGTrafficManager *) globals->get_subsystem("Traffic Manager");
      if (tmgr->isReleased(AIManagerRef))
	AIManagerRef = 0;
    }

  if (!AIManagerRef)
    {
      userLatitude  = fgGetDouble("/position/latitude-deg");
      userLongitude = fgGetDouble("/position/longitude-deg");

      //cerr << "Estimated minimum distance to user: " << distanceToUser << endl;
      // This flight entry is entirely in the past, do we need to 
      // push it forward in time to the next scheduled departure. 
      if ((i->getDepartureTime() < now) && (i->getArrivalTime() < now))
	{
	  i->update();
	  return true;
	}

      // Departure time in the past and arrival time in the future.
      // This flight is in progress, so we need to calculate it's
      // approximate position and -if in range- create an AIAircraft
      // object for it. 
      //if ((i->getDepartureTime() < now) && (i->getArrivalTime() > now))
      

      // Part of this flight is in the future.
      if (i->getArrivalTime() > now)
	{
	  dep = i->getDepartureAirport();
	  arr = i->getArrivalAirport  ();
	  if (!(dep && arr))
	    return false;
	  
	  temp = sgPolarToCart3d(Point3D(dep->getLongitude() * 
					 SG_DEGREES_TO_RADIANS, 
					 dep->getLatitude()  * 
					 SG_DEGREES_TO_RADIANS, 
					 1.0));
	  a[0] = temp.x();
	  a[1] = temp.y();
	  a[2] = temp.z();
	  
	  temp = sgPolarToCart3d(Point3D(arr->getLongitude() *
					 SG_DEGREES_TO_RADIANS,
					 arr->getLatitude()  *
					 SG_DEGREES_TO_RADIANS, 
					 1.0));
	  b[0] = temp.x();
	  b[1] = temp.y();
	  b[2] = temp.z();
	  sgdNormaliseVec3(a);
	  sgdNormaliseVec3(b);
	  sgdVectorProductVec3(cross,b,a);
	  
	  angle = sgACos(sgdScalarProductVec3(a,b));
	  
	  // Okay, at this point we have the angle between departure and 
	  // arrival airport, in degrees. From here we can interpolate the
	  // position of the aircraft by calculating the ratio between 
	  // total time enroute and elapsed time enroute. 
 
	  totalTimeEnroute     = i->getArrivalTime() - i->getDepartureTime();
	  if (now > i->getDepartureTime())
	    {
	      //err << "Lat = " << lat << ", lon = " << lon << endl;
	      //cerr << "Time diff: " << now-i->getDepartureTime() << endl;
	      elapsedTimeEnroute   = now - i->getDepartureTime();
	      remainingTimeEnroute = i->getArrivalTime()   - now;  
	    }
	  else
	    {
	      lat = dep->getLatitude();
	      lon = dep->getLongitude();
	      elapsedTimeEnroute = 0;
	      remainingTimeEnroute = totalTimeEnroute;
	    }
	  	  
	  angle *= ( (double) elapsedTimeEnroute/ (double) totalTimeEnroute);
	  
	  
	  //cout << "a = " << a[0] << " " << a[1] << " " << a[2] 
	  //     << "b = " << b[0] << " " << b[1] << " " << b[2] << endl;  
	  sgdMakeRotMat4(matrix, angle, cross); 
	  for(int j = 0; j < 3; j++)
	    {
	      newPos[j] =0.0;
	      for (int k = 0; k<3; k++)
		{
		  newPos[j] += matrix[j][k]*a[k];
		}
	    }
	  
	  temp = sgCartToPolar3d(Point3D(newPos[0], newPos[1],newPos[2]));
	  if (now > i->getDepartureTime())
	    {
	      //cerr << "Lat = " << lat << ", lon = " << lon << endl;
	      //cerr << "Time diff: " << now-i->getDepartureTime() << endl;
	      lat = temp.lat() * SG_RADIANS_TO_DEGREES;
	      lon = temp.lon() * SG_RADIANS_TO_DEGREES; 
	    }
	  else
	    {
	      lat = dep->getLatitude();
	      lon = dep->getLongitude();
	    }
	  
	  
	  SGWayPoint current  (lon,
			       lat,
			       i->getCruiseAlt());
	  SGWayPoint user (   userLongitude,
			      userLatitude,
			      i->getCruiseAlt());
	  SGWayPoint dest (   arr->getLongitude(),
			      arr->getLatitude(),
			      i->getCruiseAlt());
	  // We really only need distance to user
	  // and course to destination 
	  user.CourseAndDistance(current, &courseToUser, &distanceToUser);
	  dest.CourseAndDistance(current, &courseToDest, &distanceToDest);
	  speed =  (distanceToDest*SG_METER_TO_NM) / 
	    ((double) remainingTimeEnroute/3600.0);
	  

	  // If distance between user and simulated aircaft is less
	  // then 500nm, create this flight. At jet speeds 500 nm is roughly
	  // one hour flight time, so that would be a good approximate point
	  // to start a more detailed simulation of this aircraft.
	  //cerr << registration << " is currently enroute from " 
	  //   << dep->_id << " to " << arr->_id << "distance : " 
          //   << distanceToUser*SG_METER_TO_NM << endl;
	  if ((distanceToUser*SG_METER_TO_NM) < TRAFFICTOAIDIST)
	    {
	      string flightPlanName = dep->getId() + string("-") + arr->getId() + 
		string(".xml");
	      int alt;
	      //if  ((i->getDepartureTime() < now))
	      //{
	      //	  alt = i->getCruiseAlt() *100;
	      //	}
	      //else
	      //{
	      //	  alt = dep->_elevation+19;
	      //	}

	      // Only allow traffic to be created when the model path exists
	      SGPath mp(globals->get_fg_root());
	      mp.append(modelPath);
	      if (mp.exists()) 
	      {
		  FGAIAircraft *aircraft = new FGAIAircraft(this);
		  aircraft->setPerformance(m_class); //"jet_transport";
		  aircraft->setCompany(airline); //i->getAirline();
		  aircraft->setAcType(acType); //i->getAcType();
		  aircraft->setPath(modelPath.c_str());
		  //aircraft->setFlightPlan(flightPlanName);
		  aircraft->setLatitude(lat);
		  aircraft->setLongitude(lon);
		  aircraft->setAltitude(i->getCruiseAlt()*100); // convert from FL to feet
		  aircraft->setSpeed(speed);
		  aircraft->setBank(0);
		  aircraft->SetFlightPlan(new FGAIFlightPlan(flightPlanName, courseToDest, i->getDepartureTime(), dep, 
							     arr,true, radius, i->getCruiseAlt()*100, lat, lon, speed, flightType, acType, airline));
		  aimgr->attach(aircraft);
		  
		  
		  AIManagerRef = aircraft->getID();
		  //cerr << "Class: " << m_class << ". acType: " << acType << ". Airline: " << airline << ". Speed = " << speed << ". From " << dep->getId() << " to " << arr->getId() << ". Time Fraction = " << (remainingTimeEnroute/(double) totalTimeEnroute) << endl;
		  //cerr << "Latitude : " << lat << ". Longitude : " << lon << endl;
		  //cerr << "Dep      : " << dep->getLatitude()<< ", "<< dep->getLongitude() << endl;
		  //cerr << "Arr      : " << arr->getLatitude()<< ", "<< arr->getLongitude() << endl;
		  //cerr << "Time remaining = " << (remainingTimeEnroute/3600.0) << endl;
		  //cerr << "Total time     = " << (totalTimeEnroute/3600.0) << endl;
		  //cerr << "Distance remaining = " << distanceToDest*SG_METER_TO_NM << endl;
		  }
	      else
		{
		  SG_LOG(SG_INPUT, SG_WARN, "TrafficManager: Could not load model " << mp.str());
		}
	    }
	  return true;
    }

      // Both departure and arrival time are in the future, so this
      // the aircraft is parked at the departure airport.
      // Currently this status is mostly ignored, but in future
      // versions, code should go here that -if within user range-
      // positions these aircraft at parking locations at the airport.
  if ((i->getDepartureTime() > now) && (i->getArrivalTime() > now))
	{ 
	  dep = i->getDepartureAirport();
	  return true;
	} 
    }
  //cerr << "Traffic schedule got to beyond last clause" << endl;
    // EMH: prevent a warning, should this be 'true' instead?
    // DT: YES. Originally, this code couldn't be reached, but
    // when the "if(!(AIManagerManager))" clause is false we
    // fall through right to the end. This is a valid flow.
    // the actual value is pretty innocent, only it triggers
    // warning in TrafficManager::update().
    // (which was added as a sanity check for myself in the first place. :-)
    return true;
}


void FGAISchedule::next()
{
  flights.begin()->update();
  sort(flights.begin(), flights.end());
}

double FGAISchedule::getSpeed()
{
  double courseToUser,   courseToDest;
  double distanceToUser, distanceToDest;
  double speed, remainingTimeEnroute;
  FGAirport *dep, *arr;

  FGScheduledFlightVecIterator i = flights.begin();
  dep = i->getDepartureAirport();
  arr = i->getArrivalAirport  ();
  if (!(dep && arr))
    return 0;
 
  SGWayPoint dest (   dep->getLongitude(),
		      dep->getLatitude(),
		      i->getCruiseAlt()); 
  SGWayPoint curr (    arr->getLongitude(),
		      arr->getLatitude(),
		      i->getCruiseAlt());
  remainingTimeEnroute     = i->getArrivalTime() - i->getDepartureTime();
  dest.CourseAndDistance(curr, &courseToDest, &distanceToDest);
  speed =  (distanceToDest*SG_METER_TO_NM) / 
    ((double) remainingTimeEnroute/3600.0);
  return speed;
}


void FGAISchedule::setClosestDistanceToUser()
{
  
  
  double course;
  double dist;

  Point3D temp;
  time_t 
    totalTimeEnroute, 
    elapsedTimeEnroute;
 
  double userLatitude  = fgGetDouble("/position/latitude-deg");
  double userLongitude = fgGetDouble("/position/longitude-deg");

  FGAirport *dep;
  
#if defined( __CYGWIN__) || defined( __MINGW32__)
  #define HUGE HUGE_VAL
#endif
  distanceToUser = HUGE;
  FGScheduledFlightVecIterator i = flights.begin();
  while (i != flights.end())
    {
      dep = i->getDepartureAirport();
      //if (!(dep))
      //return HUGE;
      
      SGWayPoint user (   userLongitude,
			  userLatitude,
			  i->getCruiseAlt());
      SGWayPoint current (dep->getLongitude(),
			  dep->getLatitude(),
			  0);
      user.CourseAndDistance(current, &course, &dist);
      if (dist < distanceToUser)
	{
	  distanceToUser = dist;
	  //cerr << "Found closest distance to user for " << registration << " to be " << distanceToUser << " at airport " << dep->getId() << endl;
	}
      i++;
    }
  //return distToUser;
}