Open CASCADE Technology  6.5.4
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Defines
Public Member Functions
Convert_CompBezierCurves2dToBSplineCurve2d Class Reference

Converts a list of connecting Bezier Curves 2d to a
BSplineCurve 2d.
if possible, the continuity of the BSpline will be
increased to more than C0.

#include <Convert_CompBezierCurves2dToBSplineCurve2d.hxx>

Public Member Functions

DEFINE_STANDARD_ALLOC Convert_CompBezierCurves2dToBSplineCurve2d (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_Array1OfPnt2d &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 sequence of Bezier curves), 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 sequence of Bezier curves 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 the relative computations will be
performed by the function Perform.
When the sequence of adjacent Bezier curves is complete,
use the following functions:

void Perform ()
 Computes all the data needed to build a BSpline curve
equivalent to the sequence of adjacent Bezier curves 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
Ensure that the curves in the sequence of Bezier curves
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_Array1OfPnt2d &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
 Loads the Knots table with the knots
and the Mults table with the corresponding multiplicities
of the BSpline curve whose data is computed in this framework.
Warning


Constructor & Destructor Documentation

  • 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

  • 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 sequence of Bezier curves 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 sequence (i.e. the last point of the preceding Bezier
    curve in the sequence) of Bezier curves 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 sequence of Bezier
    curves or at the time of computation.
  • 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.
  • 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: