// Created on: 1996-03-06
// Created by: Philippe MANGIN
// Copyright (c) 1996-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _FairCurve_Energy_HeaderFile
#define _FairCurve_Energy_HeaderFile

#include <Standard.hxx>
#include <Standard_DefineAlloc.hxx>
#include <Standard_Handle.hxx>

#include <TColgp_HArray1OfPnt2d.hxx>
#include <Standard_Integer.hxx>
#include <TColgp_Array1OfXY.hxx>
#include <math_MultipleVarFunctionWithHessian.hxx>
#include <Standard_Real.hxx>
class math_Matrix;
class gp_Pnt2d;


//! necessary methodes to compute the energy of an FairCurve.
class FairCurve_Energy  : public math_MultipleVarFunctionWithHessian
{
public:

  DEFINE_STANDARD_ALLOC

  
  //! returns the number of variables of the energy.
    virtual Standard_Integer NbVariables() const Standard_OVERRIDE;
  
  //! computes the values of the Energys E for the
  //! variable <X>.
  //! Returns True if the computation was done successfully,
  //! False otherwise.
  Standard_EXPORT virtual Standard_Boolean Value (const math_Vector& X, Standard_Real& E) Standard_OVERRIDE;
  
  //! computes the gradient <G> of the energys for the
  //! variable <X>.
  //! Returns True if the computation was done successfully,
  //! False otherwise.
  Standard_EXPORT virtual Standard_Boolean Gradient (const math_Vector& X, math_Vector& G) Standard_OVERRIDE;
  
  //! computes the Energy <E> and the gradient <G> of the
  //! energy for the variable <X>.
  //! Returns True if the computation was done successfully,
  //! False otherwise.
  Standard_EXPORT virtual Standard_Boolean Values (const math_Vector& X, Standard_Real& E, math_Vector& G) Standard_OVERRIDE;
  
  //! computes the Energy  <E>, the gradient <G> and the
  //! Hessian   <H> of  the  energy  for  the   variable <X>.
  //! Returns   True  if    the  computation   was  done
  //! successfully, False otherwise.
  Standard_EXPORT virtual Standard_Boolean Values (const math_Vector& X, Standard_Real& E, math_Vector& G, math_Matrix& H) Standard_OVERRIDE;
  
  //! compute the variables <X> which correspond with the field <MyPoles>
  Standard_EXPORT virtual Standard_Boolean Variable (math_Vector& X) const;
  
  //! return  the  poles
    const Handle(TColgp_HArray1OfPnt2d)& Poles() const;




protected:

  
  //! Angles corresspond to the Ox axis
  //! ConstrOrder1(2) can be equal to 0, 1 or 2
  Standard_EXPORT FairCurve_Energy(const Handle(TColgp_HArray1OfPnt2d)& Poles, const Standard_Integer ConstrOrder1, const Standard_Integer ConstrOrder2, const Standard_Boolean WithAuxValue = Standard_False, const Standard_Real Angle1 = 0, const Standard_Real Angle2 = 0, const Standard_Integer Degree = 2, const Standard_Real Curvature1 = 0, const Standard_Real Curvature2 = 0);
  
  //! It is use internally to make the Gradient Vector <G>
  Standard_EXPORT void Gradient1 (const math_Vector& TheVector, math_Vector& G);
  
  //! It is use internally to make the Hessian Matrix <H>
  Standard_EXPORT void Hessian1 (const math_Vector& TheVector, math_Matrix& H);
  
  //! compute  the  poles which correspond with the variable X
  Standard_EXPORT virtual void ComputePoles (const math_Vector& X);
  
    Standard_Integer Indice (const Standard_Integer i, const Standard_Integer j) const;
  
  //! compute  the  pole which depend of variables and G1 constraint
  Standard_EXPORT void ComputePolesG1 (const Standard_Integer Side, const Standard_Real Lambda, const gp_Pnt2d& P1, gp_Pnt2d& P2) const;
  
  //! compute  the  pole which depend of variables and G2 constraint
  Standard_EXPORT void ComputePolesG2 (const Standard_Integer Side, const Standard_Real Lambda, const Standard_Real Rho, const gp_Pnt2d& P1, gp_Pnt2d& P2) const;
  
  //! compute the energy (and derivatives) in intermediat format
  Standard_EXPORT virtual Standard_Boolean Compute (const Standard_Integer DerivativeOrder, math_Vector& Result) = 0;


  Handle(TColgp_HArray1OfPnt2d) MyPoles;
  Standard_Integer MyContrOrder1;
  Standard_Integer MyContrOrder2;
  Standard_Boolean MyWithAuxValue;
  Standard_Integer MyNbVar;


private:



  Standard_Integer MyNbValues;
  TColgp_Array1OfXY MyLinearForm;
  TColgp_Array1OfXY MyQuadForm;
  math_Vector MyGradient;
  math_Vector MyHessian;


};


#include <FairCurve_Energy.lxx>





#endif // _FairCurve_Energy_HeaderFile