/*******************************************************************************
 
 Header:       FGTrimLong.h
 Author:       Tony Peden
 Date started: 7/1/99
 
 ------------- Copyright (C) 1999  Anthony K. Peden (apeden@earthlink.net) -------------
 
 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.
 
 
 HISTORY
--------------------------------------------------------------------------------
9/8/99   TP   Created
 
 
FUNCTIONAL DESCRIPTION
--------------------------------------------------------------------------------
 
This class takes the given set of IC's and finds the angle of attack, elevator,
and throttle setting required to fly steady level. This is currently for in-air
conditions only.  It is implemented using an iterative, one-axis-at-a-time 
scheme.  
 
 
 
********************************************************************************
SENTRY
*******************************************************************************/

#ifndef FGTRIMLONG_H
#define FGTRIMLONG_H

/*******************************************************************************
INCLUDES
*******************************************************************************/

#include "FGFDMExec.h"
#include "FGRotation.h"
#include "FGAtmosphere.h"
#include "FGState.h"
#include "FGFCS.h"
#include "FGAircraft.h"
#include "FGTranslation.h"
#include "FGPosition.h"
#include "FGAuxiliary.h"
#include "FGOutput.h"
#include "FGTrimLong.h"

#define ELEV_MIN -1
#define ELEV_MAX 1

#define THROTTLE_MIN 0
#define THROTTLE_MAX 1

/*******************************************************************************
CLASS DECLARATION
*******************************************************************************/


class FGTrimLong {
private:
  typedef float (FGTrimLong::*trimfp)(float);
  int Ncycles,Naxis,Debug;
  float Tolerance, A_Tolerance;
  float alphaMin, alphaMax;
  float wdot,udot,qdot;
  float dth;
  float udot_subits, wdot_subits, qdot_subits;
  int total_its;
  bool trimudot;
  int axis_count;

  trimfp udotf,wdotf,qdotf;
  FGFDMExec* fdmex;
  FGInitialCondition* fgic;

  void setThrottlesPct(float tt);
  int checkLimits(trimfp fp,float current,float min, float max);
  // returns false if no sign change in fp(min)*fp(max) => no solution
  bool solve(trimfp fp,float guess,float desired,float *result,float eps,float min, float max,int max_iterations,int *actual_its );
  bool findInterval(trimfp fp, float *lo, float *hi,float guess,float desired,int max_iterations);

  float udot_func(float x);
  float wdot_func(float x);
  float qdot_func(float x);

public:
  FGTrimLong(FGFDMExec *FDMExec, FGInitialCondition *FGIC);
  ~FGTrimLong(void);

  bool DoTrim(void);

  void Report(void);
  void ReportState(void);
  void TrimStats();

  inline void SetUdotTrim(bool bb) { trimudot=bb; }

  inline bool GetUdotTrim(void) { return trimudot; }

  inline void SetMaxCycles(int ii) { Ncycles = ii; }
  inline void SetMaxCyclesPerAxis(int ii) { Naxis = ii; }
  inline void SetTolerance(float tt) {
    Tolerance = tt;
    A_Tolerance = tt / 10;
  }
  //Debug level 1 shows results of each top-level iteration
  //Debug level 2 shows level 1 & results of each per-axis iteration
  inline void SetDebug(int level) { Debug = level; }
  inline void ClearDebug(void) { Debug = 0; }

};


#endif