occt/src/Geom2dConvert/Geom2dConvert_CompCurveToBSplineCurve.cxx

// Created on: 1997-04-29
// Created by: Stagiaire Francois DUMONT
// Copyright (c) 1997-1999 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 <Geom2d_BoundedCurve.hxx>
#include <Geom2d_BSplineCurve.hxx>
#include <Geom2dConvert.hxx>
#include <Geom2dConvert_CompCurveToBSplineCurve.hxx>
#include <gp_Pnt2d.hxx>
#include <gp_Vec2d.hxx>
#include <Precision.hxx>
#include <TColgp_Array1OfPnt2d.hxx>
#include <TColStd_Array1OfInteger.hxx>
#include <TColStd_Array1OfReal.hxx>

//=======================================================================
//function : constructor
//purpose  :
//=======================================================================
Geom2dConvert_CompCurveToBSplineCurve::Geom2dConvert_CompCurveToBSplineCurve (const Convert_ParameterisationType theParameterisation)
: myTol  (Precision::Confusion()),
  myType (theParameterisation)
{
  //
}

//=======================================================================
//function : constructor
//purpose  :
//=======================================================================
Geom2dConvert_CompCurveToBSplineCurve::
Geom2dConvert_CompCurveToBSplineCurve(const Handle(Geom2d_BoundedCurve)& BasisCurve, 
				      const Convert_ParameterisationType Parameterisation) :
				      myTol(Precision::Confusion()),
				      myType(Parameterisation)
{
  Handle(Geom2d_BSplineCurve) Bs = 
      Handle(Geom2d_BSplineCurve)::DownCast(BasisCurve);
  if (!Bs.IsNull()) { 
    myCurve =  Handle(Geom2d_BSplineCurve)::DownCast(BasisCurve->Copy()); 
  }
  else {
    myCurve = Geom2dConvert::CurveToBSplineCurve (BasisCurve, myType);
  }
}

//=======================================================================
//function : Add
//purpose  :
//=======================================================================

Standard_Boolean Geom2dConvert_CompCurveToBSplineCurve::
Add(const Handle(Geom2d_BoundedCurve)& NewCurve,
    const Standard_Real Tolerance,
    const Standard_Boolean After)
{
  // conversion
  Handle(Geom2d_BSplineCurve) Bs = Handle(Geom2d_BSplineCurve)::DownCast (NewCurve);
  if (!Bs.IsNull())
  {
    Bs = Handle(Geom2d_BSplineCurve)::DownCast (NewCurve->Copy());
  }
  else
  {
    Bs = Geom2dConvert::CurveToBSplineCurve (NewCurve, myType);
  }
  if (myCurve.IsNull())
  {
    myCurve = Bs;
    return Standard_True;
  }

  myTol = Tolerance;

  Standard_Integer LBs = Bs->NbPoles(), LCb = myCurve->NbPoles();
  
  // myCurve est elle fermee ?
  if (myCurve->Pole(LCb).Distance(myCurve->Pole(1)) < myTol){
    if(After){
      // Ajout Apres ?
      Standard_Real d1 = myCurve->Pole(LCb).Distance(Bs->Pole(1));
      Standard_Real d2 = myCurve->Pole(LCb).Distance(Bs->Pole(LBs));
      if (d2 < d1) {
        Bs->Reverse();
        d1 = d2;
      }
      if (d1 < myTol) {
	Add(myCurve, Bs, Standard_True);
	return Standard_True;
      }
    }
    else{
      // Ajout avant ?  
      Standard_Real d1 = myCurve->Pole(1).Distance(Bs->Pole(1));
      Standard_Real d2 = myCurve->Pole(1).Distance(Bs->Pole(LBs));
      if (d1 < d2) {
        Bs->Reverse();
        d2 = d1;
      }
      if (d2 < myTol) {
	Add(Bs, myCurve, Standard_False);
	return Standard_True;
      }
    }
  }
  // Ajout Apres ?
  else {

    Standard_Real d1 = myCurve->Pole(LCb).Distance(Bs->Pole(1));
    Standard_Real d2 = myCurve->Pole(LCb).Distance(Bs->Pole(LBs));
    if (( d1  < myTol) || ( d2 < myTol)) {
      if (d2 < d1) {Bs->Reverse();}
      Add(myCurve, Bs, Standard_True);
      return Standard_True;
    }
  // Ajout avant ?  
    else { 
      d1 = myCurve->Pole(1).Distance(Bs->Pole(1));
      d2 = myCurve->Pole(1).Distance(Bs->Pole(LBs));
      if ( (d1 < myTol) || (d2 < myTol)) {
	if (d1 < d2) {Bs->Reverse();}
	Add(Bs, myCurve, Standard_False );
	return Standard_True;
      }
    }
  }  
  return Standard_False;
}

//=======================================================================
//function : Add
//purpose  :
//=======================================================================

void Geom2dConvert_CompCurveToBSplineCurve::Add( 
      Handle(Geom2d_BSplineCurve)& FirstCurve, 
      Handle(Geom2d_BSplineCurve)& SecondCurve,
      const Standard_Boolean After)
{
// Harmonisation des degres.
  Standard_Integer Deg = Max(FirstCurve->Degree(), SecondCurve->Degree());
  if (FirstCurve->Degree() < Deg) { FirstCurve->IncreaseDegree(Deg); }
  if (SecondCurve->Degree() < Deg)  { SecondCurve->IncreaseDegree(Deg); }

// Declarationd
  Standard_Real L1, L2, U_de_raccord;
  Standard_Integer ii, jj;
  Standard_Real  Ratio=1, Ratio1, Ratio2, Delta1, Delta2;
  Standard_Integer NbP1 = FirstCurve->NbPoles(), NbP2 = SecondCurve->NbPoles();
  Standard_Integer NbK1 = FirstCurve->NbKnots(), NbK2 = SecondCurve->NbKnots();
  TColStd_Array1OfReal Noeuds (1, NbK1+NbK2-1);
  TColgp_Array1OfPnt2d Poles (1, NbP1+ NbP2-1);
  TColStd_Array1OfReal Poids  (1, NbP1+ NbP2-1);
  TColStd_Array1OfInteger Mults (1, NbK1+NbK2-1);

  // Ratio de reparametrisation (C1 si possible)
  L1 = FirstCurve->DN(FirstCurve->LastParameter(), 1).Magnitude();
  L2 = SecondCurve->DN(SecondCurve->FirstParameter(), 1). Magnitude();

  if ( (L1 > Precision::Confusion()) && (L2 > Precision::Confusion()) ) {
    Ratio = L1 / L2;
  }
  if ( (Ratio < Precision::Confusion()) || (Ratio > 1/Precision::Confusion()) ) {Ratio = 1;}

  if (After) {
// On ne bouge pas la premiere courbe
    Ratio1 = 1;
    Delta1 = 0;
    Ratio2 = 1/Ratio;
    Delta2 = Ratio2*SecondCurve->Knot(1) - FirstCurve->Knot(NbK1);
    U_de_raccord = FirstCurve->LastParameter();
  }
  else {
// On ne bouge pas la seconde courbe
    Ratio1 = Ratio;
    Delta1 = Ratio1*FirstCurve->Knot(NbK1) - SecondCurve->Knot(1);
    Ratio2 = 1;
    Delta2 = 0;
    U_de_raccord = SecondCurve->FirstParameter();
  }    

// Les Noeuds

  for (ii=1; ii<NbK1; ii++) {
    Noeuds(ii) = Ratio1*FirstCurve->Knot(ii) - Delta1;
    Mults(ii) = FirstCurve->Multiplicity(ii);
  }
  Noeuds(NbK1) = U_de_raccord;
  Mults(NbK1) = FirstCurve->Degree();
  for (ii=2, jj=NbK1+1; ii<=NbK2; ii++, jj++) {
    Noeuds(jj) = Ratio2*SecondCurve->Knot(ii) - Delta2;
    Mults(jj) = SecondCurve->Multiplicity(ii);
  } 
 Ratio = FirstCurve->Weight(NbP1) ;
 Ratio /=  SecondCurve->Weight(1) ;
// Les Poles et Poids
  for (ii=1;  ii<NbP1; ii++) {
     Poles(ii) =  FirstCurve->Pole(ii);
     Poids(ii) =  FirstCurve->Weight(ii);
   }
  for (ii=1, jj=NbP1;  ii<=NbP2; ii++, jj++) {
     Poles(jj) =   SecondCurve->Pole(ii);
//
// attentiion les poids ne se raccord pas forcement C0
// d'ou Ratio
//
     Poids(jj) =   Ratio * SecondCurve->Weight(ii);
   }
  
// Creation de la BSpline
  myCurve = new (Geom2d_BSplineCurve) (Poles, Poids, Noeuds, Mults, Deg);

// Reduction eventuelle de la multiplicite
  Standard_Boolean Ok = Standard_True;
  Standard_Integer M = Mults(NbK1);
  while ( (M>0) && Ok) {
    M--;
    Ok = myCurve->RemoveKnot(NbK1, M, myTol);
  }
}

//=======================================================================
//function : BSplineCurve
//purpose  :
//=======================================================================

Handle(Geom2d_BSplineCurve) Geom2dConvert_CompCurveToBSplineCurve::BSplineCurve() const 
{
  return myCurve;
}

//=======================================================================
//function : Clear
//purpose  :
//=======================================================================

void Geom2dConvert_CompCurveToBSplineCurve::Clear()
{
  myCurve.Nullify();
}