0031687: Draw Harness, ViewerTest - extend command vrenderparams with option updating...

[occt.git] / src / Extrema / Extrema_CurveLocator.gxx

// 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 <Standard_OutOfRange.hxx>


void Extrema_CurveLocator::Locate (const Pnt& P, const Curve1& C, 
				   const Standard_Integer NbU, 
				   POnC& Papp) {

/*-----------------------------------------------------------------------------
Fonction:
     Recherche, parmi un echantillon de 'NbU' points de la courbe C, du
    point le plus proche du point P.
    L'echantillonnage est fait a parametre constant sur l'intervalle de
    definition de la courbe.
-----------------------------------------------------------------------------*/

  if (NbU < 2) { throw Standard_OutOfRange(); }

  Standard_Real U = Tool1::FirstParameter(C);
  Standard_Real PasU = (Tool1::LastParameter(C) - U)/ (NbU - 1);
  Standard_Real Dist2Min = RealLast(), UMin=0;
  Pnt PntMin;
  Standard_Real Dist2;
  Pnt Pt;
  for ( Standard_Integer NoSample = 1; NoSample < NbU; NoSample++, U += PasU) {
    Pt = Tool1::Value(C, U);
    Dist2 = Pt.SquareDistance(P);
    if (Dist2 < Dist2Min) {
      Dist2Min = Dist2;
      UMin = U;
      PntMin = Pt;
    }
  }
  Papp.SetValues(UMin,PntMin);
}



void Extrema_CurveLocator::Locate (const Pnt& P, const Curve1& C, 
				   const Standard_Integer NbU, 
				   const Standard_Real Umin, 
				   const Standard_Real Usup,
				   POnC& Papp) {

/*-----------------------------------------------------------------------------
Fonction:
     Recherche, parmi un echantillon de 'NbU' points de la courbe C, du
    point le plus proche du point P.
    L'echantillonnage est fait a parametre constant sur l'intervalle de
    definition de la courbe.
-----------------------------------------------------------------------------*/

  if (NbU < 2) { throw Standard_OutOfRange(); }
  Standard_Real U1, U2, U11, U12;
  Standard_Real Uinf = Tool1::FirstParameter(C);
  Standard_Real Ulast = Tool1::LastParameter(C);


  U1 = Min(Uinf, Ulast);
  U2 = Max(Uinf, Ulast);
  U11 = Min(Umin, Usup);
  U12 = Max(Umin, Usup);

  if (U11 < U1 - RealEpsilon()) U11 = U1;
  if (U12 > U2 + RealEpsilon()) U12 = U2;

  Standard_Real U = U11;
  Standard_Real PasU = (U12 - U)/ (NbU - 1);
  Standard_Real Dist2Min = RealLast(), UMin=0;
  Pnt PntMin;
  Standard_Real Dist2;
  Pnt Pt;
  for ( Standard_Integer NoSample = 1; NoSample < NbU; NoSample++, U += PasU) {
    Pt = Tool1::Value(C, U);
    Dist2 = Pt.SquareDistance(P);
    if (Dist2 < Dist2Min) {
      Dist2Min = Dist2;
      UMin = U;
      PntMin = Pt;
    }
  }
  Papp.SetValues(UMin, PntMin);
}