[Jsbsim-cvslogs] CVS: JSBSim/src/initialization FGInitialCondition.h, 1.45, 1.46 FGInitialCondition.cpp, 1.110, 1.111

[Bertrand <bco...@us...>]

Update of /cvsroot/jsbsim/JSBSim/src/initialization
In directory sfp-cvs-1.v30.ch3.sourceforge.com:/tmp/cvs-serv9720/src/initialization

Modified Files:
	FGInitialCondition.h FGInitialCondition.cpp 
Log Message:
Fixed the altitude setter such that it does not modify the specified geodetic latitude.

Index: FGInitialCondition.h
===================================================================
RCS file: /cvsroot/jsbsim/JSBSim/src/initialization/FGInitialCondition.h,v
retrieving revision 1.45
retrieving revision 1.46
diff -C2 -r1.45 -r1.46
*** FGInitialCondition.h	26 Jun 2016 20:33:04 -0000	1.45
--- FGInitialCondition.h	3 Jul 2016 17:20:55 -0000	1.46
***************
*** 72,76 ****
  
  typedef enum { setvt, setvc, setve, setmach, setuvw, setned, setvg } speedset;
! typedef enum { setasl, setagl} altitudeset;
  
  /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
--- 72,77 ----
  
  typedef enum { setvt, setvc, setve, setmach, setuvw, setned, setvg } speedset;
! typedef enum { setasl, setagl } altitudeset;
! typedef enum { setgeoc, setgeod } latitudeset;
  
  /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
***************
*** 682,685 ****
--- 683,687 ----
    speedset lastSpeedSet;
    altitudeset lastAltitudeSet;
+   latitudeset lastLatitudeSet;
    unsigned int enginesRunning;
    int needTrim;
***************
*** 701,704 ****
--- 703,707 ----
    void calcAeroAngles(const FGColumnVector3& _vt_BODY);
    void calcThetaBeta(double alfa, const FGColumnVector3& _vt_NED);
+   double ComputeGeodAltitude(double geodLatitude);
    bool LoadLatitude(Element* position_el);
    void Debug(int from);

Index: FGInitialCondition.cpp
===================================================================
RCS file: /cvsroot/jsbsim/JSBSim/src/initialization/FGInitialCondition.cpp,v
retrieving revision 1.110
retrieving revision 1.111
diff -C2 -r1.110 -r1.111
*** FGInitialCondition.cpp	3 Jul 2016 14:27:48 -0000	1.110
--- FGInitialCondition.cpp	3 Jul 2016 17:20:55 -0000	1.111
***************
*** 105,108 ****
--- 105,110 ----
    position.SetLatitude(latRad0);
    position.SetAltitudeAGL(altAGLFt0);
+   lastLatitudeSet = setgeoc;
+   lastAltitudeSet = setagl;
  
    orientation = FGQuaternion(phi0, theta0, psi0);
***************
*** 148,151 ****
--- 150,154 ----
    lastSpeedSet = setvt;
    lastAltitudeSet = setasl;
+   lastLatitudeSet = setgeoc;
    enginesRunning = 0;
    needTrim = 0;
***************
*** 703,709 ****
--- 706,718 ----
    double PitotAngle = Aircraft->GetPitotAngle();
  
+   double geodLatitude = position.GetGeodLatitudeRad();
    altitudeASL=alt;
    position.SetAltitudeASL(alt);
  
+   if (lastLatitudeSet == setgeod) {
+     double h = ComputeGeodAltitude(geodLatitude);
+     position.SetPositionGeodetic(position.GetLongitude(), geodLatitude, h);
+   }
+ 
    soundSpeed = Atmosphere->GetSoundSpeed(altitudeASL);
    rho = Atmosphere->GetDensity(altitudeASL);
***************
*** 735,738 ****
--- 744,749 ----
    double altitude;
  
+   lastLatitudeSet = setgeoc;
+ 
    switch(lastAltitudeSet) {
    case setagl:
***************
*** 742,748 ****
      break;
    default:
-     altitude = position.GetAltitudeASL();
      position.SetLatitude(lat);
!     position.SetAltitudeASL(altitude);
    }
  }
--- 753,758 ----
      break;
    default:
      position.SetLatitude(lat);
!     break;
    }
  }
***************
*** 911,919 ****
  
  //******************************************************************************
! // Load the latitude from the XML file. The computations below assume that the
! // terrain is a sphere and that the elevation is uniform all over the Earth.
! // Would that assumption fail, the computation below would need to be adapted
! // since the position radius would depend on the terrain elevation which depends
! // itself on the latitude.
  //
  // This is an acceptable trade off because this routine is only used by
--- 921,930 ----
  
  //******************************************************************************
! // Given an altitude above the sea level (or a position radius which is the
! // same) and a geodetic latitude, compute the geodetic altitude. It is assumed
! // that the terrain is a sphere and that the elevation is uniform all over the
! // Earth.  Would that assumption fail, the computation below would need to be
! // adapted since the position radius would depend on the terrain elevation which
! // depends itself on the latitude.
  //
  // This is an acceptable trade off because this routine is only used by
***************
*** 921,924 ****
--- 932,947 ----
  // Earth is a sphere.
  
+ double FGInitialCondition::ComputeGeodAltitude(double geodLatitude)
+ {
+   double R = position.GetRadius();
+   double slat = sin(geodLatitude);
+   double RN = a / sqrt(1.0 - e2*slat*slat);
+   double p1 = e2*RN*slat*slat;
+   double p2 = e2*e2*RN*RN*slat*slat-R*R;
+   return p1 + sqrt(p1*p1-p2) - RN;
+ }
+ 
+ //******************************************************************************
+ 
  bool FGInitialCondition::LoadLatitude(Element* position_el)
  {
***************
*** 946,959 ****
  
      if (lat_type == "geod" || lat_type == "geodetic") {
!       double R = position.GetRadius();
!       double slat = sin(latitude);
!       double RN = a / sqrt(1.0 - e2*slat*slat);
!       double p1 = e2*RN*slat*slat;
!       double p2 = e2*e2*RN*RN*slat*slat-R*R;
!       double h = p1 + sqrt(p1*p1-p2) - RN;
        position.SetPositionGeodetic(position.GetLongitude(), latitude, h);
      }
!     else
        position.SetLatitude(latitude);
    }
  
--- 969,980 ----
  
      if (lat_type == "geod" || lat_type == "geodetic") {
!       double h = ComputeGeodAltitude(latitude);
        position.SetPositionGeodetic(position.GetLongitude(), latitude, h);
+       lastLatitudeSet = setgeod;
      }
!     else {
        position.SetLatitude(latitude);
+       lastLatitudeSet = setgeoc;
+     }
    }