Open CASCADE Technology 6.6.0
Public Member Functions
Convert_CompBezierCurvesToBSplineCurve Class Reference

An algorithm to convert a sequence of adjacent
non-rational Bezier curves into a BSpline curve.
A CompBezierCurvesToBSplineCurve object provides a framework for:
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#include <Convert_CompBezierCurvesToBSplineCurve.hxx>

Public Member Functions

 Convert_CompBezierCurvesToBSplineCurve (const Standard_Real AngularTolerance=1.0e-4)
 Constructs a framework for converting a sequence of
adjacent non-rational Bezier curves into a BSpline curve.
Knots will be created on the computed BSpline curve at
each junction point of two consecutive Bezier curves. The
degree of continuity of the BSpline curve will be increased at
the junction point of two consecutive Bezier curves if their
tangent vectors at this point are parallel. AngularTolerance
(given in radians, and defaulted to 1.0 e-4) will be used
to check the parallelism of the two tangent vectors.
Use the following functions:

void AddCurve (const TColgp_Array1OfPnt &Poles)
 Adds the Bezier curve defined by the table of poles Poles, to
the sequence (still contained in this framework) of adjacent
Bezier curves to be converted into a BSpline curve.
Only polynomial (i.e. non-rational) Bezier curves are
converted using this framework.
If this is not the first call to the function (i.e. if this framework
still contains data in its Bezier curve sequence), the degree
of continuity of the BSpline curve will be increased at the
time of computation at the first point of the added Bezier
curve (i.e. the first point of the Poles table). This will be the
case if the tangent vector of the curve at this point is
parallel to the tangent vector at the end point of the
preceding Bezier curve in the Bezier curve sequence still
contained in this framework. An angular tolerance given at
the time of construction of this framework will be used to
check the parallelism of the two tangent vectors. This
checking procedure and all related computations will be
performed by the Perform function.
When the adjacent Bezier curve sequence is complete, use
the following functions:

void Perform ()
 Computes all the data needed to build a BSpline curve
equivalent to the adjacent Bezier curve sequence still
contained in this framework.
A knot is inserted on the computed BSpline curve at the
junction point of two consecutive Bezier curves. The
degree of continuity of the BSpline curve will be increased
at the junction point of two consecutive Bezier curves if
their tangent vectors at this point are parallel. An angular
tolerance given at the time of construction of this
framework is used to check the parallelism of the two
tangent vectors.
Use the available consultation functions to access the
computed data. This data may then be used to construct
the BSpline curve.
Warning
Make sure that the curves in the Bezier curve sequence
contained in this framework are adjacent. An error may
occur at the time of computation if this condition is not
satisfied. Particular care must be taken with respect to the
above as this condition is not checked, either when
defining the Bezier curve sequence or at the time of computation.

Standard_Integer Degree () const
 Returns the degree of the BSpline curve whose data is
computed in this framework.
Warning
Take particular care not to use this function before the
computation is performed (Perform function), as this
condition is not checked and an error may therefore occur.

Standard_Integer NbPoles () const
 Returns the number of poles of the BSpline curve whose
data is computed in this framework.
Warning
Take particular care not to use this function before the
computation is performed (Perform function), as this
condition is not checked and an error may therefore occur.

void Poles (TColgp_Array1OfPnt &Poles) const
 Loads the Poles table with the poles of the BSpline curve
whose data is computed in this framework.
Warning

Standard_Integer NbKnots () const
 Returns the number of knots of the BSpline curve whose
data is computed in this framework.
Warning
Take particular care not to use this function before the
computation is performed (Perform function), as this
condition is not checked and an error may therefore occur.

void KnotsAndMults (TColStd_Array1OfReal &Knots, TColStd_Array1OfInteger &Mults) const

Detailed Description


Constructor & Destructor Documentation

Convert_CompBezierCurvesToBSplineCurve::Convert_CompBezierCurvesToBSplineCurve ( const Standard_Real  AngularTolerance = 1.0e-4)
  • AddCurve to define in sequence the adjacent Bezier
    curves to be converted,
  • Perform to compute the data needed to build the BSpline curve,
  • and the available consultation functions to access the
    computed data. This data may be used to construct the BSpline curve.

Member Function Documentation

void Convert_CompBezierCurvesToBSplineCurve::AddCurve ( const TColgp_Array1OfPnt Poles)
  • Perform to compute the data needed to build the BSpline curve,
  • and the available consultation functions to access the
    computed data. This data may be used to construct the BSpline curve.
    Warning
    The Bezier curve sequence treated by this framework is
    automatically initialized with the first Bezier curve when the
    function is first called. During subsequent use of this function,
    ensure that the first point of the added Bezier curve (i.e. the
    first point of the Poles table) is coincident with the last point
    of the Bezier curve sequence (i.e. the last point of the
    preceding Bezier curve in the sequence) still contained in
    this framework. An error may occur at the time of
    computation if this condition is not satisfied. Particular care
    must be taken with respect to the above, as this condition is
    not checked either when defining the Bezier curve
    sequence or at the time of computation.
Standard_Integer Convert_CompBezierCurvesToBSplineCurve::Degree ( ) const
void Convert_CompBezierCurvesToBSplineCurve::KnotsAndMults ( TColStd_Array1OfReal Knots,
TColStd_Array1OfInteger Mults 
) const
  • loads the Knots table with the knots,
  • and loads the Mults table with the corresponding multiplicities
    of the BSpline curve whose data is computed in this framework.
    Warning
  • Do not use this function before the computation is
    performed (Perform function).
  • The length of the Knots and Mults arrays must be equal
    to the number of knots in the BSpline curve whose data is
    computed in this framework.
    Particular care must be taken with respect to the above as
    these conditions are not checked, and an error may occur.
Standard_Integer Convert_CompBezierCurvesToBSplineCurve::NbKnots ( ) const
Standard_Integer Convert_CompBezierCurvesToBSplineCurve::NbPoles ( ) const
void Convert_CompBezierCurvesToBSplineCurve::Perform ( )
void Convert_CompBezierCurvesToBSplineCurve::Poles ( TColgp_Array1OfPnt Poles) const
  • Do not use this function before the computation is
    performed (Perform function).
  • The length of the Poles array must be equal to the
    number of poles of the BSpline curve whose data is
    computed in this framework.
    Particular care must be taken with respect to the above, as
    these conditions are not checked, and an error may occur.

The documentation for this class was generated from the following file:
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