[occt.git] / src / Approx / Approx_CurveOnSurface.cxx

// Created on: 1997-10-06
// Created by: Roman BORISOV
// 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 <Adaptor2d_HCurve2d.hxx>
#include <Adaptor3d_CurveOnSurface.hxx>
#include <Adaptor3d_HCurve.hxx>
#include <Adaptor3d_HCurveOnSurface.hxx>
#include <Adaptor3d_HSurface.hxx>
#include <AdvApprox_ApproxAFunction.hxx>
#include <AdvApprox_DichoCutting.hxx>
#include <AdvApprox_PrefAndRec.hxx>
#include <Approx_CurveOnSurface.hxx>
#include <Geom2d_BSplineCurve.hxx>
#include <Geom2dAdaptor_HCurve.hxx>
#include <Geom_BSplineCurve.hxx>
#include <Geom_TrimmedCurve.hxx>
#include <GeomAdaptor_HCurve.hxx>
#include <GeomAdaptor_HSurface.hxx>
#include <GeomConvert.hxx>
#include <gp_Pnt.hxx>
#include <gp_Vec.hxx>
#include <Precision.hxx>
#include <Standard_ConstructionError.hxx>
#include <Standard_OutOfRange.hxx>
#include <TColgp_Array1OfPnt.hxx>
#include <TColgp_Array1OfPnt2d.hxx>
#include <TColStd_Array1OfReal.hxx>
#include <TColStd_HArray1OfReal.hxx>

//=======================================================================
//class : Approx_CurveOnSurface_Eval
//purpose: evaluator class for approximation of both 2d and 3d curves
//=======================================================================
class Approx_CurveOnSurface_Eval : public AdvApprox_EvaluatorFunction
{
 public:
  Approx_CurveOnSurface_Eval (const Handle(Adaptor3d_HCurve)& theFunc, 
                              const Handle(Adaptor2d_HCurve2d)& theFunc2d, 
                              Standard_Real First, Standard_Real Last)
    : fonct(theFunc), fonct2d(theFunc2d) 
      { StartEndSav[0] = First; StartEndSav[1] = Last; }
  
  virtual void Evaluate (Standard_Integer *Dimension,
		         Standard_Real     StartEnd[2],
                         Standard_Real    *Parameter,
                         Standard_Integer *DerivativeRequest,
                         Standard_Real    *Result, // [Dimension]
                         Standard_Integer *ErrorCode);
  
 private:
  Handle(Adaptor3d_HCurve) fonct;
  Handle(Adaptor2d_HCurve2d) fonct2d;
  Standard_Real StartEndSav[2];
};

void Approx_CurveOnSurface_Eval::Evaluate (Standard_Integer *Dimension,
                                           Standard_Real     StartEnd[2],
                                           Standard_Real    *Param, // Parameter at which evaluation
                                           Standard_Integer *Order, // Derivative Request
                                           Standard_Real    *Result,// [Dimension]
                                           Standard_Integer *ErrorCode)
{
  *ErrorCode = 0;
  Standard_Real par = *Param;

// Dimension is incorrect
  if (*Dimension != 5) {
    *ErrorCode = 1;
  }

// Parameter is incorrect
  if(StartEnd[0] != StartEndSav[0] || StartEnd[1]!= StartEndSav[1]) 
    {
      fonct = fonct->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
      fonct2d = fonct2d->Trim(StartEnd[0],StartEnd[1],
				Precision::PConfusion());
      StartEndSav[0]=StartEnd[0];
      StartEndSav[1]=StartEnd[1];
    }
  gp_Pnt pnt;


  gp_Pnt2d pnt2d;

  switch (*Order) {
  case 0: 
    {
      fonct2d->D0(par, pnt2d);
      fonct->D0(par, pnt);
      Result[0] = pnt2d.X();
      Result[1] = pnt2d.Y();
      Result[2] = pnt.X();
      Result[3] = pnt.Y();
      Result[4] = pnt.Z();
      break;
    }
  case 1:
    {
      gp_Vec v1;
      gp_Vec2d v21;
      fonct2d->D1(par, pnt2d, v21);
      fonct->D1(par,pnt, v1);
      Result[0] = v21.X();
      Result[1] = v21.Y();
      Result[2] = v1.X();
      Result[3] = v1.Y();
      Result[4] = v1.Z();
      break;
  }
  case 2:
    {
      gp_Vec v1, v2;
      gp_Vec2d v21, v22;    
      fonct2d->D2(par, pnt2d, v21, v22);
      fonct->D2(par, pnt, v1, v2);         
      Result[0] = v22.X();
      Result[1] = v22.Y();
      Result[2] = v2.X();
      Result[3] = v2.Y();
      Result[4] = v2.Z();
      break;
    }
  default:
    Result[0] = Result[1] = Result[2] = Result[3] = Result[4] = 0.;
    *ErrorCode = 3;
    break;
  }
}

//=======================================================================
//class : Approx_CurveOnSurface_Eval3d
//purpose: evaluator class for approximation of 3d curve
//=======================================================================

class Approx_CurveOnSurface_Eval3d : public AdvApprox_EvaluatorFunction
{
 public:
  Approx_CurveOnSurface_Eval3d (const Handle(Adaptor3d_HCurve)& theFunc, 
                                Standard_Real First, Standard_Real Last)
    : fonct(theFunc) { StartEndSav[0] = First; StartEndSav[1] = Last; }
  
  virtual void Evaluate (Standard_Integer *Dimension,
		         Standard_Real     StartEnd[2],
                         Standard_Real    *Parameter,
                         Standard_Integer *DerivativeRequest,
                         Standard_Real    *Result, // [Dimension]
                         Standard_Integer *ErrorCode);
  
 private:
  Handle(Adaptor3d_HCurve) fonct;
  Standard_Real StartEndSav[2];
};

void Approx_CurveOnSurface_Eval3d::Evaluate (Standard_Integer *Dimension,
                                             Standard_Real     StartEnd[2],
                                             Standard_Real    *Param, // Parameter at which evaluation
                                             Standard_Integer *Order, // Derivative Request
                                             Standard_Real    *Result,// [Dimension]
                                             Standard_Integer *ErrorCode)
{
  *ErrorCode = 0;
  Standard_Real par = *Param;

// Dimension is incorrect
  if (*Dimension != 3) {
    *ErrorCode = 1;
  }

// Parameter is incorrect
  if(StartEnd[0] != StartEndSav[0] || StartEnd[1]!= StartEndSav[1]) 
    {
      fonct = fonct->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
      StartEndSav[0]=StartEnd[0];
      StartEndSav[1]=StartEnd[1];
    }

  gp_Pnt pnt;

  switch (*Order) {
  case 0:
    pnt = fonct->Value(par);
    Result[0] = pnt.X();
    Result[1] = pnt.Y();
    Result[2] = pnt.Z();
    break;
  case 1:
    {
      gp_Vec v1;
      fonct->D1(par, pnt, v1);
      Result[0] = v1.X();
      Result[1] = v1.Y();
      Result[2] = v1.Z();
      break;
    }
  case 2:
    {
      gp_Vec v1, v2;
      fonct->D2(par, pnt, v1, v2);
      Result[0] = v2.X();
      Result[1] = v2.Y();
      Result[2] = v2.Z();
      break;
    }
  default:
    Result[0] = Result[1] = Result[2] = 0.;
    *ErrorCode = 3;
    break;
  }
}

//=======================================================================
//class : Approx_CurveOnSurface_Eval2d
//purpose: evaluator class for approximation of 2d curve
//=======================================================================

class Approx_CurveOnSurface_Eval2d : public AdvApprox_EvaluatorFunction
{
 public:
  Approx_CurveOnSurface_Eval2d (const Handle(Adaptor2d_HCurve2d)& theFunc2d, 
                                Standard_Real First, Standard_Real Last)
    : fonct2d(theFunc2d) { StartEndSav[0] = First; StartEndSav[1] = Last; }
  
  virtual void Evaluate (Standard_Integer *Dimension,
		         Standard_Real     StartEnd[2],
                         Standard_Real    *Parameter,
                         Standard_Integer *DerivativeRequest,
                         Standard_Real    *Result, // [Dimension]
                         Standard_Integer *ErrorCode);
  
 private:
  Handle(Adaptor2d_HCurve2d) fonct2d;
  Standard_Real StartEndSav[2];
};

void Approx_CurveOnSurface_Eval2d::Evaluate (Standard_Integer *Dimension,
                                             Standard_Real     StartEnd[2],
                                             Standard_Real    *Param, // Parameter at which evaluation
                                             Standard_Integer *Order, // Derivative Request
                                             Standard_Real    *Result,// [Dimension]
                                             Standard_Integer *ErrorCode)
{
  *ErrorCode = 0;
  Standard_Real par = *Param;

// Dimension is incorrect
  if (*Dimension != 2) {
    *ErrorCode = 1;
  }

// Parameter is incorrect
  if(StartEnd[0] != StartEndSav[0] || StartEnd[1]!= StartEndSav[1]) 
    {
      fonct2d = fonct2d->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
      StartEndSav[0]=StartEnd[0];
      StartEndSav[1]=StartEnd[1];
    }
 
  gp_Pnt2d pnt;

  switch (*Order) {
  case 0:
    {
      pnt = fonct2d->Value(par);
      Result[0] = pnt.X();
      Result[1] = pnt.Y();
      break;
    }
  case 1:
    {
      gp_Vec2d v1;
      fonct2d->D1(par, pnt, v1);
      Result[0] = v1.X();
      Result[1] = v1.Y();
      break;
    }
  case 2:
    {
      gp_Vec2d v1, v2;
      fonct2d->D2(par, pnt, v1, v2);
      Result[0] = v2.X();
      Result[1] = v2.Y();
      break;
    }
  default:
    Result[0] = Result[1] = 0.;
    *ErrorCode = 3;
    break;
  }
}

//=============================================================================
//function : Approx_CurveOnSurface
//purpose  : Constructor
//=============================================================================
 Approx_CurveOnSurface::Approx_CurveOnSurface(const Handle(Adaptor2d_HCurve2d)& C2D,
					      const Handle(Adaptor3d_HSurface)& Surf,
					      const Standard_Real First,
					      const Standard_Real Last,
					      const Standard_Real Tol,
					      const GeomAbs_Shape S,
					      const Standard_Integer MaxDegree,
					      const Standard_Integer MaxSegments, 
					      const Standard_Boolean only3d, 
					      const Standard_Boolean only2d)
: myC2D(C2D),
  mySurf(Surf),
  myFirst(First),
  myLast(Last),
  myTol(Tol),
  myIsDone(Standard_False),
  myHasResult(Standard_False),
  myError3d(0.0),
  myError2dU(0.0),
  myError2dV(0.0)
 {
   Perform(MaxSegments, MaxDegree, S, only3d, only2d);
 }

//=============================================================================
//function : Approx_CurveOnSurface
//purpose  : Constructor
//=============================================================================
 Approx_CurveOnSurface::Approx_CurveOnSurface(const Handle(Adaptor2d_HCurve2d)& theC2D,
                                              const Handle(Adaptor3d_HSurface)& theSurf,
                                              const Standard_Real               theFirst,
                                              const Standard_Real               theLast,
                                              const Standard_Real               theTol)
: myC2D(theC2D),
  mySurf(theSurf),
  myFirst(theFirst),
  myLast(theLast),
  myTol(theTol),
  myIsDone(Standard_False),
  myHasResult(Standard_False),
  myError3d(0.0),
  myError2dU(0.0),
  myError2dV(0.0)
{
}

//=============================================================================
//function : Perform
//purpose  :
//=============================================================================
void Approx_CurveOnSurface::Perform(const Standard_Integer theMaxSegments,
                                    const Standard_Integer theMaxDegree,
                                    const GeomAbs_Shape    theContinuity,
                                    const Standard_Boolean theOnly3d,
                                    const Standard_Boolean theOnly2d)
{
  myIsDone = Standard_False;
  myHasResult = Standard_False;
  myError2dU = 0.0;
  myError2dV = 0.0;
  myError3d = 0.0;

  if(theOnly3d && theOnly2d) throw Standard_ConstructionError();

  Handle( Adaptor2d_HCurve2d ) TrimmedC2D = myC2D->Trim( myFirst, myLast, Precision::PConfusion() );

  Standard_Boolean isU, isForward;
  Standard_Real aParam;
  if (theOnly3d && isIsoLine(TrimmedC2D, isU, aParam, isForward))
  {
    if (buildC3dOnIsoLine(TrimmedC2D, isU, aParam, isForward))
    {
      myIsDone = Standard_True;
      myHasResult = Standard_True;
      return;
    }
  }

  Adaptor3d_CurveOnSurface COnS( TrimmedC2D, mySurf );
  Handle(Adaptor3d_HCurveOnSurface) HCOnS = new Adaptor3d_HCurveOnSurface();
  HCOnS->Set(COnS);

  Standard_Integer Num1DSS = 0, Num2DSS=0, Num3DSS=0;
  Handle(TColStd_HArray1OfReal) OneDTol;
  Handle(TColStd_HArray1OfReal) TwoDTolNul;
  Handle(TColStd_HArray1OfReal) ThreeDTol;

  // create evaluators and choose appropriate one
  Approx_CurveOnSurface_Eval3d Eval3dCvOnSurf (HCOnS,             myFirst, myLast);
  Approx_CurveOnSurface_Eval2d Eval2dCvOnSurf (       TrimmedC2D, myFirst, myLast);
  Approx_CurveOnSurface_Eval   EvalCvOnSurf   (HCOnS, TrimmedC2D, myFirst, myLast);
  AdvApprox_EvaluatorFunction* EvalPtr;
  if ( theOnly3d ) EvalPtr = &Eval3dCvOnSurf;
  else if ( theOnly2d ) EvalPtr = &Eval2dCvOnSurf;
  else EvalPtr = &EvalCvOnSurf;

  // Initialization for 2d approximation
  if(!theOnly3d) {
    Num1DSS = 2;
    OneDTol = new TColStd_HArray1OfReal(1,Num1DSS);

    Standard_Real TolU, TolV;

    TolU = mySurf->UResolution(myTol)/2;
    TolV = mySurf->VResolution(myTol)/2;

    OneDTol->SetValue(1,TolU);
    OneDTol->SetValue(2,TolV);
  }
  
  if(!theOnly2d) {
    Num3DSS=1;
    ThreeDTol = new TColStd_HArray1OfReal(1,Num3DSS);
    ThreeDTol->Init(myTol/2);
  }


  Standard_Integer NbInterv_C2 = HCOnS->NbIntervals(GeomAbs_C2);
  TColStd_Array1OfReal CutPnts_C2(1, NbInterv_C2 + 1);
  HCOnS->Intervals(CutPnts_C2, GeomAbs_C2);
  Standard_Integer NbInterv_C3 = HCOnS->NbIntervals(GeomAbs_C3);
  TColStd_Array1OfReal CutPnts_C3(1, NbInterv_C3 + 1);
  HCOnS->Intervals(CutPnts_C3, GeomAbs_C3);
  
  AdvApprox_PrefAndRec CutTool(CutPnts_C2,CutPnts_C3);
  AdvApprox_ApproxAFunction aApprox (Num1DSS, Num2DSS, Num3DSS, 
	      			     OneDTol, TwoDTolNul, ThreeDTol,
				     myFirst, myLast, theContinuity,
				     theMaxDegree, theMaxSegments,
				     *EvalPtr, CutTool);

  myIsDone = aApprox.IsDone();
  myHasResult = aApprox.HasResult();
  
  if (myHasResult) {
    Handle(TColStd_HArray1OfReal)    Knots = aApprox.Knots();
    Handle(TColStd_HArray1OfInteger) Mults = aApprox.Multiplicities();
    Standard_Integer Degree = aApprox.Degree();

    if(!theOnly2d) 
      {
	TColgp_Array1OfPnt Poles(1,aApprox.NbPoles());
	aApprox.Poles(1,Poles);
	myCurve3d = new Geom_BSplineCurve(Poles, Knots->Array1(), Mults->Array1(), Degree);
	myError3d = aApprox.MaxError(3, 1);
      }
    if(!theOnly3d) 
      {
	TColgp_Array1OfPnt2d Poles2d(1,aApprox.NbPoles());
	TColStd_Array1OfReal Poles1dU(1,aApprox.NbPoles());
	aApprox.Poles1d(1, Poles1dU);
	TColStd_Array1OfReal Poles1dV(1,aApprox.NbPoles());
	aApprox.Poles1d(2, Poles1dV);
	for(Standard_Integer i = 1; i <= aApprox.NbPoles(); i++)
	  Poles2d.SetValue(i, gp_Pnt2d(Poles1dU.Value(i), Poles1dV.Value(i)));
	myCurve2d = new Geom2d_BSplineCurve(Poles2d, Knots->Array1(), Mults->Array1(), Degree);
	
	myError2dU = aApprox.MaxError(1, 1);
	myError2dV = aApprox.MaxError(1, 2);
      }
  }
  
}

 Standard_Boolean Approx_CurveOnSurface::IsDone() const
{
  return myIsDone;
}

 Standard_Boolean Approx_CurveOnSurface::HasResult() const
{
  return myHasResult;
}

 Handle(Geom_BSplineCurve) Approx_CurveOnSurface::Curve3d() const
{
  return myCurve3d;
}

 Handle(Geom2d_BSplineCurve) Approx_CurveOnSurface::Curve2d() const
{
  return myCurve2d;
}

 Standard_Real Approx_CurveOnSurface::MaxError3d() const
{
  return myError3d;
}

 Standard_Real Approx_CurveOnSurface::MaxError2dU() const
{
  return myError2dU;
}

 Standard_Real Approx_CurveOnSurface::MaxError2dV() const
{
  return myError2dV;
}

//=============================================================================
//function : isIsoLine
//purpose  :
//=============================================================================
Standard_Boolean Approx_CurveOnSurface::isIsoLine(const Handle(Adaptor2d_HCurve2d) theC2D,
                                                  Standard_Boolean&                theIsU,
                                                  Standard_Real&                   theParam,
                                                  Standard_Boolean&                theIsForward) const
{
  // These variables are used to check line state (vertical or horizontal).
  Standard_Boolean isAppropriateType = Standard_False;
  gp_Pnt2d aLoc2d;
  gp_Dir2d aDir2d;

  // Test type.
  const GeomAbs_CurveType aType = theC2D->GetType();
  if (aType == GeomAbs_Line)
  {
    gp_Lin2d aLin2d = theC2D->Line();
    aLoc2d = aLin2d.Location();
    aDir2d = aLin2d.Direction();
    isAppropriateType = Standard_True;
  }
  else if (aType == GeomAbs_BSplineCurve)
  {
    Handle(Geom2d_BSplineCurve) aBSpline2d = theC2D->BSpline();
    if (aBSpline2d->Degree() != 1 || aBSpline2d->NbPoles() != 2)
      return Standard_False; // Not a line or uneven parameterization.

    aLoc2d = aBSpline2d->Pole(1);

    // Vector should be non-degenerated.
    gp_Vec2d aVec2d(aBSpline2d->Pole(1), aBSpline2d->Pole(2));
    if (aVec2d.SquareMagnitude() < Precision::Confusion())
      return Standard_False; // Degenerated spline.
    aDir2d = aVec2d;

    isAppropriateType = Standard_True;
  }
  else if (aType == GeomAbs_BezierCurve)
  {
    Handle(Geom2d_BezierCurve) aBezier2d = theC2D->Bezier();
    if (aBezier2d->Degree() != 1 || aBezier2d->NbPoles() != 2)
      return Standard_False; // Not a line or uneven parameterization.

    aLoc2d = aBezier2d->Pole(1);

    // Vector should be non-degenerated.
    gp_Vec2d aVec2d(aBezier2d->Pole(1), aBezier2d->Pole(2));
    if (aVec2d.SquareMagnitude() < Precision::Confusion())
      return Standard_False; // Degenerated spline.
    aDir2d = aVec2d;

    isAppropriateType = Standard_True;
  }

  if (!isAppropriateType)
    return Standard_False;

  // Check line to be vertical or horizontal.
  if (aDir2d.IsParallel(gp::DX2d(), Precision::Angular()))
  {
    // Horizontal line. V = const.
    theIsU = Standard_False;
    theParam = aLoc2d.Y();
    theIsForward = aDir2d.Dot(gp::DX2d()) > 0.0;
    return Standard_True;
  }
  else if (aDir2d.IsParallel(gp::DY2d(), Precision::Angular()))
  {
    // Vertical line. U = const.
    theIsU = Standard_True;
    theParam = aLoc2d.X();
    theIsForward = aDir2d.Dot(gp::DY2d()) > 0.0;
    return Standard_True;
  }

  return Standard_False;
}

#include <GeomLib.hxx>

//=============================================================================
//function : buildC3dOnIsoLine
//purpose  :
//=============================================================================
Standard_Boolean Approx_CurveOnSurface::buildC3dOnIsoLine(const Handle(Adaptor2d_HCurve2d) theC2D,
                                                          const Standard_Boolean           theIsU,
                                                          const Standard_Real              theParam,
                                                          const Standard_Boolean           theIsForward)
{
  // Convert adapter to the appropriate type.
  Handle(GeomAdaptor_HSurface) aGeomAdapter = Handle(GeomAdaptor_HSurface)::DownCast(mySurf);
  if (aGeomAdapter.IsNull())
    return Standard_False;

  if (mySurf->GetType() == GeomAbs_Sphere)
    return Standard_False;

  // Extract isoline
  Handle(Geom_Surface) aSurf = aGeomAdapter->ChangeSurface().Surface();
  Handle(Geom_Curve) aC3d;

  gp_Pnt2d aF2d = theC2D->Value(theC2D->FirstParameter());
  gp_Pnt2d aL2d = theC2D->Value(theC2D->LastParameter());

  if (theIsU)
  {
    aC3d = aSurf->UIso(theParam);
    aC3d = new Geom_TrimmedCurve(aC3d, aF2d.Y(), aL2d.Y());
  }
  else
  {
    aC3d = aSurf->VIso(theParam);
    aC3d = new Geom_TrimmedCurve(aC3d, aF2d.X(), aL2d.X());
  }

  // Convert arbitrary curve type to the b-spline.
  myCurve3d = GeomConvert::CurveToBSplineCurve(aC3d, Convert_QuasiAngular);
  if (!theIsForward)
    myCurve3d->Reverse();

  // Rebuild parameterization for the 3d curve to have the same parameterization with
  // a two-dimensional curve. 
  TColStd_Array1OfReal aKnots = myCurve3d->Knots();
  BSplCLib::Reparametrize(theC2D->FirstParameter(), theC2D->LastParameter(), aKnots);
  myCurve3d->SetKnots(aKnots);

  // Evaluate error.
  myError3d = 0.0;

  const Standard_Real aParF = myFirst;
  const Standard_Real aParL = myLast;
  const Standard_Integer aNbPnt = 23;
  for(Standard_Integer anIdx = 0; anIdx <= aNbPnt; ++anIdx)
  {
    const Standard_Real aPar = aParF + ((aParL - aParF) * anIdx) / aNbPnt;

    const gp_Pnt2d aPnt2d = theC2D->Value(aPar);

    const gp_Pnt aPntC3D = myCurve3d->Value(aPar);
    const gp_Pnt aPntC2D = mySurf->Value(aPnt2d.X(), aPnt2d.Y());

    const Standard_Real aSqDeviation = aPntC3D.SquareDistance(aPntC2D);
    myError3d = Max(aSqDeviation, myError3d);
  }

  myError3d = Sqrt(myError3d);

  // Target tolerance is not obtained. This situation happens for isolines on the sphere.
  // OCCT is unable to convert it keeping original parameterization, while the geometric
  // form of the result is entirely identical. In that case, it is better to utilize
  // a general-purpose approach. 
  if (myError3d > myTol)
    return Standard_False;

  return Standard_True;
}
Commit	Line	Data
b311480e	1	// Created on: 1997-10-06
	2	// Created by: Roman BORISOV
	3	// Copyright (c) 1997-1999 Matra Datavision
973c2be1	4	// Copyright (c) 1999-2014 OPEN CASCADE SAS
b311480e	5	//
973c2be1	6	// This file is part of Open CASCADE Technology software library.
b311480e	7	//
d5f74e42	8	// This library is free software; you can redistribute it and/or modify it under
d5f74e42	9	// the terms of the GNU Lesser General Public License version 2.1 as published
973c2be1	10	// by the Free Software Foundation, with special exception defined in the file
	11	// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
	12	// distribution for complete text of the license and disclaimer of any warranty.
b311480e	13	//
973c2be1	14	// Alternatively, this file may be used under the terms of Open CASCADE
973c2be1	15	// commercial license or contractual agreement.
7fd59977	16
42cf5bc1	17
42cf5bc1	18	#include <Adaptor2d_HCurve2d.hxx>
7fd59977	19	#include <Adaptor3d_CurveOnSurface.hxx>
7fd59977	20	#include <Adaptor3d_HCurve.hxx>
7fd59977	21	#include <Adaptor3d_HCurveOnSurface.hxx>
42cf5bc1	22	#include <Adaptor3d_HSurface.hxx>
	23	#include <AdvApprox_ApproxAFunction.hxx>
	24	#include <AdvApprox_DichoCutting.hxx>
	25	#include <AdvApprox_PrefAndRec.hxx>
	26	#include <Approx_CurveOnSurface.hxx>
	27	#include <Geom2d_BSplineCurve.hxx>
	28	#include <Geom2dAdaptor_HCurve.hxx>
	29	#include <Geom_BSplineCurve.hxx>
f04de133	30	#include <Geom_TrimmedCurve.hxx>
42cf5bc1	31	#include <GeomAdaptor_HCurve.hxx>
42cf5bc1	32	#include <GeomAdaptor_HSurface.hxx>
f04de133	33	#include <GeomConvert.hxx>
42cf5bc1	34	#include <gp_Pnt.hxx>
	35	#include <gp_Vec.hxx>
	36	#include <Precision.hxx>
	37	#include <Standard_ConstructionError.hxx>
	38	#include <Standard_OutOfRange.hxx>
	39	#include <TColgp_Array1OfPnt.hxx>
7fd59977	40	#include <TColgp_Array1OfPnt2d.hxx>
7fd59977	41	#include <TColStd_Array1OfReal.hxx>
42cf5bc1	42	#include <TColStd_HArray1OfReal.hxx>
7fd59977	43
	44	//=======================================================================
	45	//class : Approx_CurveOnSurface_Eval
	46	//purpose: evaluator class for approximation of both 2d and 3d curves
	47	//=======================================================================
7fd59977	48	class Approx_CurveOnSurface_Eval : public AdvApprox_EvaluatorFunction
	49	{
	50	public:
	51	Approx_CurveOnSurface_Eval (const Handle(Adaptor3d_HCurve)& theFunc,
	52	const Handle(Adaptor2d_HCurve2d)& theFunc2d,
	53	Standard_Real First, Standard_Real Last)
	54	: fonct(theFunc), fonct2d(theFunc2d)
	55	{ StartEndSav[0] = First; StartEndSav[1] = Last; }
	56
	57	virtual void Evaluate (Standard_Integer *Dimension,
	58	Standard_Real StartEnd[2],
	59	Standard_Real *Parameter,
	60	Standard_Integer *DerivativeRequest,
	61	Standard_Real *Result, // [Dimension]
	62	Standard_Integer *ErrorCode);
	63
	64	private:
	65	Handle(Adaptor3d_HCurve) fonct;
	66	Handle(Adaptor2d_HCurve2d) fonct2d;
	67	Standard_Real StartEndSav[2];
	68	};
	69
	70	void Approx_CurveOnSurface_Eval::Evaluate (Standard_Integer *Dimension,
	71	Standard_Real StartEnd[2],
	72	Standard_Real *Param, // Parameter at which evaluation
	73	Standard_Integer *Order, // Derivative Request
	74	Standard_Real *Result,// [Dimension]
	75	Standard_Integer *ErrorCode)
	76	{
	77	*ErrorCode = 0;
	78	Standard_Real par = *Param;
	79
	80	// Dimension is incorrect
	81	if (*Dimension != 5) {
	82	*ErrorCode = 1;
	83	}
	84
	85	// Parameter is incorrect
	86	if(StartEnd[0] != StartEndSav[0] \|\| StartEnd[1]!= StartEndSav[1])
	87	{
	88	fonct = fonct->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
	89	fonct2d = fonct2d->Trim(StartEnd[0],StartEnd[1],
	90	Precision::PConfusion());
	91	StartEndSav[0]=StartEnd[0];
	92	StartEndSav[1]=StartEnd[1];
	93	}
	94	gp_Pnt pnt;
	95
	96
	97	gp_Pnt2d pnt2d;
	98
	99	switch (*Order) {
	100	case 0:
	101	{
	102	fonct2d->D0(par, pnt2d);
	103	fonct->D0(par, pnt);
	104	Result[0] = pnt2d.X();
	105	Result[1] = pnt2d.Y();
	106	Result[2] = pnt.X();
	107	Result[3] = pnt.Y();
	108	Result[4] = pnt.Z();
	109	break;
	110	}
	111	case 1:
112	{
113	gp_Vec v1;
114	gp_Vec2d v21;
115	fonct2d->D1(par, pnt2d, v21);
116	fonct->D1(par,pnt, v1);
117	Result[0] = v21.X();
118	Result[1] = v21.Y();
119	Result[2] = v1.X();
120	Result[3] = v1.Y();
121	Result[4] = v1.Z();
122	break;
123	}
124	case 2:
125	{
126	gp_Vec v1, v2;
127	gp_Vec2d v21, v22;
128	fonct2d->D2(par, pnt2d, v21, v22);
129	fonct->D2(par, pnt, v1, v2);
130	Result[0] = v22.X();
131	Result[1] = v22.Y();
132	Result[2] = v2.X();
133	Result[3] = v2.Y();
134	Result[4] = v2.Z();
135	break;
136	}
137	default:
138	Result[0] = Result[1] = Result[2] = Result[3] = Result[4] = 0.;
139	*ErrorCode = 3;
140	break;
141	}
142	}
143
144	//=======================================================================
145	//class : Approx_CurveOnSurface_Eval3d
146	//purpose: evaluator class for approximation of 3d curve
147	//=======================================================================
148
149	class Approx_CurveOnSurface_Eval3d : public AdvApprox_EvaluatorFunction
150	{
151	public:
152	Approx_CurveOnSurface_Eval3d (const Handle(Adaptor3d_HCurve)& theFunc,
153	Standard_Real First, Standard_Real Last)
154	: fonct(theFunc) { StartEndSav[0] = First; StartEndSav[1] = Last; }
155
156	virtual void Evaluate (Standard_Integer *Dimension,
157	Standard_Real StartEnd[2],
158	Standard_Real *Parameter,
159	Standard_Integer *DerivativeRequest,
160	Standard_Real *Result, // [Dimension]
161	Standard_Integer *ErrorCode);
162
163	private:
164	Handle(Adaptor3d_HCurve) fonct;
165	Standard_Real StartEndSav[2];
166	};
167
168	void Approx_CurveOnSurface_Eval3d::Evaluate (Standard_Integer *Dimension,
169	Standard_Real StartEnd[2],
170	Standard_Real *Param, // Parameter at which evaluation
171	Standard_Integer *Order, // Derivative Request
172	Standard_Real *Result,// [Dimension]
173	Standard_Integer *ErrorCode)
174	{
175	*ErrorCode = 0;
176	Standard_Real par = *Param;
177
178	// Dimension is incorrect
179	if (*Dimension != 3) {
180	*ErrorCode = 1;
181	}
182
183	// Parameter is incorrect
184	if(StartEnd[0] != StartEndSav[0] \|\| StartEnd[1]!= StartEndSav[1])
185	{
186	fonct = fonct->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
187	StartEndSav[0]=StartEnd[0];
188	StartEndSav[1]=StartEnd[1];
189	}
190
191	gp_Pnt pnt;
192
193	switch (*Order) {
194	case 0:
195	pnt = fonct->Value(par);
196	Result[0] = pnt.X();
197	Result[1] = pnt.Y();
198	Result[2] = pnt.Z();
199	break;
200	case 1:
201	{
202	gp_Vec v1;
203	fonct->D1(par, pnt, v1);
204	Result[0] = v1.X();
205	Result[1] = v1.Y();
206	Result[2] = v1.Z();
207	break;
208	}
209	case 2:
210	{
211	gp_Vec v1, v2;
212	fonct->D2(par, pnt, v1, v2);
213	Result[0] = v2.X();
214	Result[1] = v2.Y();
215	Result[2] = v2.Z();
216	break;
217	}
218	default:
219	Result[0] = Result[1] = Result[2] = 0.;
220	*ErrorCode = 3;
221	break;
222	}
223	}
224
225	//=======================================================================
226	//class : Approx_CurveOnSurface_Eval2d
227	//purpose: evaluator class for approximation of 2d curve
228	//=======================================================================
229
230	class Approx_CurveOnSurface_Eval2d : public AdvApprox_EvaluatorFunction
231	{
232	public:
233	Approx_CurveOnSurface_Eval2d (const Handle(Adaptor2d_HCurve2d)& theFunc2d,
234	Standard_Real First, Standard_Real Last)
235	: fonct2d(theFunc2d) { StartEndSav[0] = First; StartEndSav[1] = Last; }
236
237	virtual void Evaluate (Standard_Integer *Dimension,
238	Standard_Real StartEnd[2],
239	Standard_Real *Parameter,
240	Standard_Integer *DerivativeRequest,
241	Standard_Real *Result, // [Dimension]
242	Standard_Integer *ErrorCode);
243
244	private:
245	Handle(Adaptor2d_HCurve2d) fonct2d;
246	Standard_Real StartEndSav[2];
247	};
248
249	void Approx_CurveOnSurface_Eval2d::Evaluate (Standard_Integer *Dimension,
250	Standard_Real StartEnd[2],
251	Standard_Real *Param, // Parameter at which evaluation
252	Standard_Integer *Order, // Derivative Request
253	Standard_Real *Result,// [Dimension]
254	Standard_Integer *ErrorCode)
255	{
256	*ErrorCode = 0;
257	Standard_Real par = *Param;
258
259	// Dimension is incorrect
260	if (*Dimension != 2) {
261	*ErrorCode = 1;
262	}
263
264	// Parameter is incorrect
265	if(StartEnd[0] != StartEndSav[0] \|\| StartEnd[1]!= StartEndSav[1])
266	{
267	fonct2d = fonct2d->Trim(StartEnd[0],StartEnd[1],Precision::PConfusion());
268	StartEndSav[0]=StartEnd[0];
269	StartEndSav[1]=StartEnd[1];
270	}
271
272	gp_Pnt2d pnt;
273
274	switch (*Order) {
275	case 0:
276	{
277	pnt = fonct2d->Value(par);
278	Result[0] = pnt.X();
279	Result[1] = pnt.Y();
280	break;
281	}
282	case 1:
283	{
284	gp_Vec2d v1;
285	fonct2d->D1(par, pnt, v1);
286	Result[0] = v1.X();
287	Result[1] = v1.Y();
288	break;
289	}
290	case 2:
291	{
292	gp_Vec2d v1, v2;
293	fonct2d->D2(par, pnt, v1, v2);
294	Result[0] = v2.X();
295	Result[1] = v2.Y();
296	break;
297	}
298	default:
299	Result[0] = Result[1] = 0.;
300	*ErrorCode = 3;
301	break;
302	}
303	}
304
f04de133	305	//=============================================================================
	306	//function : Approx_CurveOnSurface
	307	//purpose : Constructor
	308	//=============================================================================
7fd59977	309	Approx_CurveOnSurface::Approx_CurveOnSurface(const Handle(Adaptor2d_HCurve2d)& C2D,
	310	const Handle(Adaptor3d_HSurface)& Surf,
	311	const Standard_Real First,
	312	const Standard_Real Last,
	313	const Standard_Real Tol,
	314	const GeomAbs_Shape S,
	315	const Standard_Integer MaxDegree,
	316	const Standard_Integer MaxSegments,
	317	const Standard_Boolean only3d,
	318	const Standard_Boolean only2d)
f04de133	319	: myC2D(C2D),
	320	mySurf(Surf),
	321	myFirst(First),
	322	myLast(Last),
	323	myTol(Tol),
	324	myIsDone(Standard_False),
	325	myHasResult(Standard_False),
	326	myError3d(0.0),
	327	myError2dU(0.0),
	328	myError2dV(0.0)
	329	{
	330	Perform(MaxSegments, MaxDegree, S, only3d, only2d);
	331	}
	332
	333	//=============================================================================
	334	//function : Approx_CurveOnSurface
	335	//purpose : Constructor
	336	//=============================================================================
	337	Approx_CurveOnSurface::Approx_CurveOnSurface(const Handle(Adaptor2d_HCurve2d)& theC2D,
	338	const Handle(Adaptor3d_HSurface)& theSurf,
	339	const Standard_Real theFirst,
	340	const Standard_Real theLast,
	341	const Standard_Real theTol)
	342	: myC2D(theC2D),
	343	mySurf(theSurf),
	344	myFirst(theFirst),
	345	myLast(theLast),
	346	myTol(theTol),
	347	myIsDone(Standard_False),
	348	myHasResult(Standard_False),
	349	myError3d(0.0),
	350	myError2dU(0.0),
	351	myError2dV(0.0)
	352	{
	353	}
	354
	355	//=============================================================================
	356	//function : Perform
	357	//purpose :
	358	//=============================================================================
	359	void Approx_CurveOnSurface::Perform(const Standard_Integer theMaxSegments,
	360	const Standard_Integer theMaxDegree,
	361	const GeomAbs_Shape theContinuity,
	362	const Standard_Boolean theOnly3d,
	363	const Standard_Boolean theOnly2d)
7fd59977	364	{
7fd59977	365	myIsDone = Standard_False;
f04de133	366	myHasResult = Standard_False;
	367	myError2dU = 0.0;
	368	myError2dV = 0.0;
	369	myError3d = 0.0;
7fd59977	370
f04de133	371	if(theOnly3d && theOnly2d) throw Standard_ConstructionError();
	372
	373	Handle( Adaptor2d_HCurve2d ) TrimmedC2D = myC2D->Trim( myFirst, myLast, Precision::PConfusion() );
	374
	375	Standard_Boolean isU, isForward;
	376	Standard_Real aParam;
	377	if (theOnly3d && isIsoLine(TrimmedC2D, isU, aParam, isForward))
	378	{
	379	if (buildC3dOnIsoLine(TrimmedC2D, isU, aParam, isForward))
	380	{
	381	myIsDone = Standard_True;
	382	myHasResult = Standard_True;
	383	return;
	384	}
	385	}
7fd59977	386
f04de133	387	Adaptor3d_CurveOnSurface COnS( TrimmedC2D, mySurf );
7fd59977	388	Handle(Adaptor3d_HCurveOnSurface) HCOnS = new Adaptor3d_HCurveOnSurface();
	389	HCOnS->Set(COnS);
	390
	391	Standard_Integer Num1DSS = 0, Num2DSS=0, Num3DSS=0;
	392	Handle(TColStd_HArray1OfReal) OneDTol;
	393	Handle(TColStd_HArray1OfReal) TwoDTolNul;
	394	Handle(TColStd_HArray1OfReal) ThreeDTol;
	395
	396	// create evaluators and choose appropriate one
f04de133	397	Approx_CurveOnSurface_Eval3d Eval3dCvOnSurf (HCOnS, myFirst, myLast);
	398	Approx_CurveOnSurface_Eval2d Eval2dCvOnSurf ( TrimmedC2D, myFirst, myLast);
	399	Approx_CurveOnSurface_Eval EvalCvOnSurf (HCOnS, TrimmedC2D, myFirst, myLast);
7fd59977	400	AdvApprox_EvaluatorFunction* EvalPtr;
f04de133	401	if ( theOnly3d ) EvalPtr = &Eval3dCvOnSurf;
f04de133	402	else if ( theOnly2d ) EvalPtr = &Eval2dCvOnSurf;
7fd59977	403	else EvalPtr = &EvalCvOnSurf;
	404
	405	// Initialization for 2d approximation
f04de133	406	if(!theOnly3d) {
7fd59977	407	Num1DSS = 2;
	408	OneDTol = new TColStd_HArray1OfReal(1,Num1DSS);
	409
	410	Standard_Real TolU, TolV;
	411
f04de133	412	TolU = mySurf->UResolution(myTol)/2;
f04de133	413	TolV = mySurf->VResolution(myTol)/2;
7fd59977	414
	415	OneDTol->SetValue(1,TolU);
	416	OneDTol->SetValue(2,TolV);
	417	}
	418
f04de133	419	if(!theOnly2d) {
7fd59977	420	Num3DSS=1;
7fd59977	421	ThreeDTol = new TColStd_HArray1OfReal(1,Num3DSS);
f04de133	422	ThreeDTol->Init(myTol/2);
7fd59977	423	}
7fd59977	424
7fd59977	425
	426	Standard_Integer NbInterv_C2 = HCOnS->NbIntervals(GeomAbs_C2);
	427	TColStd_Array1OfReal CutPnts_C2(1, NbInterv_C2 + 1);
	428	HCOnS->Intervals(CutPnts_C2, GeomAbs_C2);
	429	Standard_Integer NbInterv_C3 = HCOnS->NbIntervals(GeomAbs_C3);
	430	TColStd_Array1OfReal CutPnts_C3(1, NbInterv_C3 + 1);
	431	HCOnS->Intervals(CutPnts_C3, GeomAbs_C3);
	432
	433	AdvApprox_PrefAndRec CutTool(CutPnts_C2,CutPnts_C3);
	434	AdvApprox_ApproxAFunction aApprox (Num1DSS, Num2DSS, Num3DSS,
	435	OneDTol, TwoDTolNul, ThreeDTol,
f04de133	436	myFirst, myLast, theContinuity,
f04de133	437	theMaxDegree, theMaxSegments,
7fd59977	438	*EvalPtr, CutTool);
	439
	440	myIsDone = aApprox.IsDone();
	441	myHasResult = aApprox.HasResult();
	442
	443	if (myHasResult) {
	444	Handle(TColStd_HArray1OfReal) Knots = aApprox.Knots();
	445	Handle(TColStd_HArray1OfInteger) Mults = aApprox.Multiplicities();
	446	Standard_Integer Degree = aApprox.Degree();
	447
f04de133	448	if(!theOnly2d)
7fd59977	449	{
	450	TColgp_Array1OfPnt Poles(1,aApprox.NbPoles());
	451	aApprox.Poles(1,Poles);
	452	myCurve3d = new Geom_BSplineCurve(Poles, Knots->Array1(), Mults->Array1(), Degree);
	453	myError3d = aApprox.MaxError(3, 1);
	454	}
f04de133	455	if(!theOnly3d)
7fd59977	456	{
	457	TColgp_Array1OfPnt2d Poles2d(1,aApprox.NbPoles());
	458	TColStd_Array1OfReal Poles1dU(1,aApprox.NbPoles());
	459	aApprox.Poles1d(1, Poles1dU);
	460	TColStd_Array1OfReal Poles1dV(1,aApprox.NbPoles());
	461	aApprox.Poles1d(2, Poles1dV);
	462	for(Standard_Integer i = 1; i <= aApprox.NbPoles(); i++)
	463	Poles2d.SetValue(i, gp_Pnt2d(Poles1dU.Value(i), Poles1dV.Value(i)));
	464	myCurve2d = new Geom2d_BSplineCurve(Poles2d, Knots->Array1(), Mults->Array1(), Degree);
	465
	466	myError2dU = aApprox.MaxError(1, 1);
	467	myError2dV = aApprox.MaxError(1, 2);
	468	}
	469	}
	470
7fd59977	471	}
	472
	473	Standard_Boolean Approx_CurveOnSurface::IsDone() const
	474	{
	475	return myIsDone;
	476	}
	477
	478	Standard_Boolean Approx_CurveOnSurface::HasResult() const
	479	{
	480	return myHasResult;
	481	}
	482
	483	Handle(Geom_BSplineCurve) Approx_CurveOnSurface::Curve3d() const
	484	{
	485	return myCurve3d;
	486	}
	487
	488	Handle(Geom2d_BSplineCurve) Approx_CurveOnSurface::Curve2d() const
	489	{
	490	return myCurve2d;
	491	}
	492
	493	Standard_Real Approx_CurveOnSurface::MaxError3d() const
	494	{
	495	return myError3d;
	496	}
	497
	498	Standard_Real Approx_CurveOnSurface::MaxError2dU() const
	499	{
	500	return myError2dU;
	501	}
	502
	503	Standard_Real Approx_CurveOnSurface::MaxError2dV() const
	504	{
	505	return myError2dV;
	506	}
	507
f04de133	508	//=============================================================================
	509	//function : isIsoLine
	510	//purpose :
	511	//=============================================================================
	512	Standard_Boolean Approx_CurveOnSurface::isIsoLine(const Handle(Adaptor2d_HCurve2d) theC2D,
	513	Standard_Boolean& theIsU,
	514	Standard_Real& theParam,
	515	Standard_Boolean& theIsForward) const
	516	{
	517	// These variables are used to check line state (vertical or horizontal).
	518	Standard_Boolean isAppropriateType = Standard_False;
	519	gp_Pnt2d aLoc2d;
	520	gp_Dir2d aDir2d;
	521
	522	// Test type.
	523	const GeomAbs_CurveType aType = theC2D->GetType();
	524	if (aType == GeomAbs_Line)
	525	{
	526	gp_Lin2d aLin2d = theC2D->Line();
	527	aLoc2d = aLin2d.Location();
	528	aDir2d = aLin2d.Direction();
	529	isAppropriateType = Standard_True;
	530	}
	531	else if (aType == GeomAbs_BSplineCurve)
	532	{
	533	Handle(Geom2d_BSplineCurve) aBSpline2d = theC2D->BSpline();
	534	if (aBSpline2d->Degree() != 1 \|\| aBSpline2d->NbPoles() != 2)
	535	return Standard_False; // Not a line or uneven parameterization.
	536
	537	aLoc2d = aBSpline2d->Pole(1);
	538
	539	// Vector should be non-degenerated.
	540	gp_Vec2d aVec2d(aBSpline2d->Pole(1), aBSpline2d->Pole(2));
	541	if (aVec2d.SquareMagnitude() < Precision::Confusion())
	542	return Standard_False; // Degenerated spline.
	543	aDir2d = aVec2d;
	544
	545	isAppropriateType = Standard_True;
	546	}
	547	else if (aType == GeomAbs_BezierCurve)
	548	{
	549	Handle(Geom2d_BezierCurve) aBezier2d = theC2D->Bezier();
	550	if (aBezier2d->Degree() != 1 \|\| aBezier2d->NbPoles() != 2)
	551	return Standard_False; // Not a line or uneven parameterization.
	552
	553	aLoc2d = aBezier2d->Pole(1);
	554
	555	// Vector should be non-degenerated.
	556	gp_Vec2d aVec2d(aBezier2d->Pole(1), aBezier2d->Pole(2));
	557	if (aVec2d.SquareMagnitude() < Precision::Confusion())
	558	return Standard_False; // Degenerated spline.
	559	aDir2d = aVec2d;
	560
	561	isAppropriateType = Standard_True;
	562	}
	563
	564	if (!isAppropriateType)
	565	return Standard_False;
	566
	567	// Check line to be vertical or horizontal.
	568	if (aDir2d.IsParallel(gp::DX2d(), Precision::Angular()))
	569	{
	570	// Horizontal line. V = const.
	571	theIsU = Standard_False;
572	theParam = aLoc2d.Y();
573	theIsForward = aDir2d.Dot(gp::DX2d()) > 0.0;
574	return Standard_True;
575	}
576	else if (aDir2d.IsParallel(gp::DY2d(), Precision::Angular()))
577	{
578	// Vertical line. U = const.
579	theIsU = Standard_True;
580	theParam = aLoc2d.X();
581	theIsForward = aDir2d.Dot(gp::DY2d()) > 0.0;
582	return Standard_True;
583	}
584
585	return Standard_False;
586	}
587
588	#include <GeomLib.hxx>
589
590	//=============================================================================
591	//function : buildC3dOnIsoLine
592	//purpose :
593	//=============================================================================
594	Standard_Boolean Approx_CurveOnSurface::buildC3dOnIsoLine(const Handle(Adaptor2d_HCurve2d) theC2D,
595	const Standard_Boolean theIsU,
596	const Standard_Real theParam,
597	const Standard_Boolean theIsForward)
598	{
599	// Convert adapter to the appropriate type.
600	Handle(GeomAdaptor_HSurface) aGeomAdapter = Handle(GeomAdaptor_HSurface)::DownCast(mySurf);
601	if (aGeomAdapter.IsNull())
602	return Standard_False;
603
604	if (mySurf->GetType() == GeomAbs_Sphere)
605	return Standard_False;
606
607	// Extract isoline
608	Handle(Geom_Surface) aSurf = aGeomAdapter->ChangeSurface().Surface();
609	Handle(Geom_Curve) aC3d;
610
611	gp_Pnt2d aF2d = theC2D->Value(theC2D->FirstParameter());
612	gp_Pnt2d aL2d = theC2D->Value(theC2D->LastParameter());
613
614	if (theIsU)
615	{
616	aC3d = aSurf->UIso(theParam);
617	aC3d = new Geom_TrimmedCurve(aC3d, aF2d.Y(), aL2d.Y());
618	}
619	else
620	{
621	aC3d = aSurf->VIso(theParam);
622	aC3d = new Geom_TrimmedCurve(aC3d, aF2d.X(), aL2d.X());
623	}
624
625	// Convert arbitrary curve type to the b-spline.
626	myCurve3d = GeomConvert::CurveToBSplineCurve(aC3d, Convert_QuasiAngular);
627	if (!theIsForward)
628	myCurve3d->Reverse();
629
630	// Rebuild parameterization for the 3d curve to have the same parameterization with
631	// a two-dimensional curve.
632	TColStd_Array1OfReal aKnots = myCurve3d->Knots();
633	BSplCLib::Reparametrize(theC2D->FirstParameter(), theC2D->LastParameter(), aKnots);
634	myCurve3d->SetKnots(aKnots);
635
636	// Evaluate error.
637	myError3d = 0.0;
638
639	const Standard_Real aParF = myFirst;
640	const Standard_Real aParL = myLast;
641	const Standard_Integer aNbPnt = 23;
642	for(Standard_Integer anIdx = 0; anIdx <= aNbPnt; ++anIdx)
643	{
644	const Standard_Real aPar = aParF + ((aParL - aParF) * anIdx) / aNbPnt;
645
646	const gp_Pnt2d aPnt2d = theC2D->Value(aPar);
647
648	const gp_Pnt aPntC3D = myCurve3d->Value(aPar);
649	const gp_Pnt aPntC2D = mySurf->Value(aPnt2d.X(), aPnt2d.Y());
650
651	const Standard_Real aSqDeviation = aPntC3D.SquareDistance(aPntC2D);
652	myError3d = Max(aSqDeviation, myError3d);
653	}
654
655	myError3d = Sqrt(myError3d);
656
657	// Target tolerance is not obtained. This situation happens for isolines on the sphere.
658	// OCCT is unable to convert it keeping original parameterization, while the geometric
659	// form of the result is entirely identical. In that case, it is better to utilize
660	// a general-purpose approach.
661	if (myError3d > myTol)
662	return Standard_False;
663
664	return Standard_True;
665	}