occt/src/Extrema/Extrema_GenLocateExtPC.gxx

// Created on: 1995-07-18
// Created by: Modelistation
// Copyright (c) 1995-1999 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.

#include <StdFail_NotDone.hxx>
#include <Standard_DomainError.hxx>
#include <math_FunctionRoot.hxx>

//=======================================================================
//function : Extrema_GenLocateExtPC
//purpose  : 
//=======================================================================

Extrema_GenLocateExtPC::Extrema_GenLocateExtPC() 
{ 
  myDone = Standard_False; 
}


//=======================================================================
//function : Extrema_GenLocateExtPC
//purpose  : 
//=======================================================================

Extrema_GenLocateExtPC::Extrema_GenLocateExtPC (const Pnt&          P,
						const Curve&        C,
						const Standard_Real U0, 
						const Standard_Real TolU)
{
  Initialize(C, Tool::FirstParameter(C), Tool::LastParameter(C), TolU);
  Perform(P, U0);
}


//=======================================================================
//function : Extrema_GenLocateExtPC
//purpose  : 
//=======================================================================

Extrema_GenLocateExtPC::Extrema_GenLocateExtPC (const Pnt&          P,
						const Curve&        C,
						const Standard_Real U0, 
						const Standard_Real Umin,
						const Standard_Real Usup,
						const Standard_Real TolU)
{
  Initialize(C, Umin, Usup, TolU);
  Perform(P, U0);
}


//=======================================================================
//function : Initialize
//purpose  : 
//=======================================================================

void Extrema_GenLocateExtPC::Initialize(const Curve&        C,
					const Standard_Real Umin,
					const Standard_Real Usup,
					const Standard_Real TolU)
{
  myDone = Standard_False;
  myF.Initialize(C);
  myumin = Umin;
  myusup = Usup;
  mytolU = TolU;
}


//=======================================================================
//function : Perform
//purpose  : 
//=======================================================================

void Extrema_GenLocateExtPC::Perform(const Pnt&          P,
				     const Standard_Real U0)

/*-----------------------------------------------------------------------------
Fonction:
  Recherche de la valeur de parametre U telle que:
  - dist(P,C(u)) passe par un extremum,
  - U soit la solution la plus proche de U0.

Methode:
  Si U est solution, alors F(U)=(C(U)-P).C'(U) = 0.
  Le probleme consiste a rechercher, dans l'intervalle de definition
  de la courbe, la racine de F la plus proche de U0.
  On utilise la classe math_FunctionRoot avec les arguments de
  construction suivants:
  - F: Extrema_FuncExtPC cree a partir de P et C,
  - U0,
  - TolU,
  - Uinf: borne inferieure de l'intervalle de definition,
  - Ulast: borne superieure de l'intervalle de definition,
  - 100. .
-----------------------------------------------------------------------------*/
{
  myF.SetPoint(P);
  math_FunctionRoot S (myF, U0, mytolU, myumin, myusup);
  myDone = S.IsDone();
  if (myDone) {
    Standard_Real uu, ff;
    POnC PP = Point();
    uu = PP.Parameter();
    if(myF.Value(uu, ff)) {
      if (Abs(ff) >= 1.e-07) myDone = Standard_False;
    }
    else myDone = Standard_False;
  }
}

//=======================================================================
//function : IsDone
//purpose  : 
//=======================================================================

Standard_Boolean Extrema_GenLocateExtPC::IsDone () const 
{
  return myDone;
}


//=======================================================================
//function : Value
//purpose  : 
//=======================================================================

Standard_Real Extrema_GenLocateExtPC::SquareDistance() const 
{
  if (!myDone) { throw StdFail_NotDone(); }
  return myF.SquareDistance(1);
}


//=======================================================================
//function : IsMin
//purpose  : 
//=======================================================================

Standard_Boolean Extrema_GenLocateExtPC::IsMin () const 
{
  if (!myDone) { throw StdFail_NotDone(); }
  return myF.IsMin(1);
}


//=======================================================================
//function : Point
//purpose  : 
//=======================================================================

const POnC & Extrema_GenLocateExtPC::Point () const 
{
  if (!myDone) { throw StdFail_NotDone(); }
  return myF.Point(1);
}