Open CASCADE Technology  7.7.0.dev
Public Member Functions

Geom2dConvert_BSplineCurveKnotSplitting Class Reference

An algorithm to determine points at which a BSpline curve should be split in order to obtain arcs of the same continuity. If you require curves with a minimum continuity for your computation, it is useful to know the points between which an arc has a continuity of a given order. The continuity order is given at the construction time. For a BSpline curve, the discontinuities are localized at the knot values. Between two knot values the BSpline is infinitely and continuously differentiable. At a given knot, the continuity is equal to: Degree - Mult, where Degree is the degree of the BSpline curve and Mult is the multiplicity of the knot. It is possible to compute the arcs which correspond to this splitting using the global function SplitBSplineCurve provided by the package Geom2dConvert. A BSplineCurveKnotSplitting object provides a framework for: More...

#include <Geom2dConvert_BSplineCurveKnotSplitting.hxx>

Public Member Functions

 Geom2dConvert_BSplineCurveKnotSplitting (const Handle< Geom2d_BSplineCurve > &BasisCurve, const Standard_Integer ContinuityRange)
 Determines points at which the BSpline curve BasisCurve should be split in order to obtain arcs with a degree of continuity equal to ContinuityRange. These points are knot values of BasisCurve. They are identified by indices in the knots table of BasisCurve. Use the available interrogation functions to access computed values, followed by the global function SplitBSplineCurve (provided by the package Geom2dConvert) to split the curve. Exceptions Standard_RangeError if ContinuityRange is less than zero. More...
 
Standard_Integer NbSplits () const
 Returns the number of points at which the analysed BSpline curve should be split, in order to obtain arcs with the continuity required by this framework. All these points correspond to knot values. Note that the first and last points of the curve, which bound the first and last arcs, are counted among these splitting points. More...
 
void Splitting (TColStd_Array1OfInteger &SplitValues) const
 Loads the SplitValues table with the split knots values computed in this framework. Each value in the table is an index in the knots table of the BSpline curve analysed by this algorithm. The values in SplitValues are given in ascending order and comprise the indices of the knots which give the first and last points of the curve. Use two consecutive values from the table as arguments of the global function SplitBSplineCurve (provided by the package Geom2dConvert) to split the curve. Exceptions Standard_DimensionError if the array SplitValues was not created with the following bounds: More...
 
Standard_Integer SplitValue (const Standard_Integer Index) const
 Returns the split knot of index Index to the split knots table computed in this framework. The returned value is an index in the knots table of the BSpline curve analysed by this algorithm. Notes: More...
 

Detailed Description

An algorithm to determine points at which a BSpline curve should be split in order to obtain arcs of the same continuity. If you require curves with a minimum continuity for your computation, it is useful to know the points between which an arc has a continuity of a given order. The continuity order is given at the construction time. For a BSpline curve, the discontinuities are localized at the knot values. Between two knot values the BSpline is infinitely and continuously differentiable. At a given knot, the continuity is equal to: Degree - Mult, where Degree is the degree of the BSpline curve and Mult is the multiplicity of the knot. It is possible to compute the arcs which correspond to this splitting using the global function SplitBSplineCurve provided by the package Geom2dConvert. A BSplineCurveKnotSplitting object provides a framework for:

Constructor & Destructor Documentation

◆ Geom2dConvert_BSplineCurveKnotSplitting()

Geom2dConvert_BSplineCurveKnotSplitting::Geom2dConvert_BSplineCurveKnotSplitting ( const Handle< Geom2d_BSplineCurve > &  BasisCurve,
const Standard_Integer  ContinuityRange 
)

Determines points at which the BSpline curve BasisCurve should be split in order to obtain arcs with a degree of continuity equal to ContinuityRange. These points are knot values of BasisCurve. They are identified by indices in the knots table of BasisCurve. Use the available interrogation functions to access computed values, followed by the global function SplitBSplineCurve (provided by the package Geom2dConvert) to split the curve. Exceptions Standard_RangeError if ContinuityRange is less than zero.

Member Function Documentation

◆ NbSplits()

Standard_Integer Geom2dConvert_BSplineCurveKnotSplitting::NbSplits ( ) const

Returns the number of points at which the analysed BSpline curve should be split, in order to obtain arcs with the continuity required by this framework. All these points correspond to knot values. Note that the first and last points of the curve, which bound the first and last arcs, are counted among these splitting points.

◆ Splitting()

void Geom2dConvert_BSplineCurveKnotSplitting::Splitting ( TColStd_Array1OfInteger SplitValues) const

Loads the SplitValues table with the split knots values computed in this framework. Each value in the table is an index in the knots table of the BSpline curve analysed by this algorithm. The values in SplitValues are given in ascending order and comprise the indices of the knots which give the first and last points of the curve. Use two consecutive values from the table as arguments of the global function SplitBSplineCurve (provided by the package Geom2dConvert) to split the curve. Exceptions Standard_DimensionError if the array SplitValues was not created with the following bounds:

  • 1, and
  • the number of split points computed in this framework (as given by the function NbSplits).

◆ SplitValue()

Standard_Integer Geom2dConvert_BSplineCurveKnotSplitting::SplitValue ( const Standard_Integer  Index) const

Returns the split knot of index Index to the split knots table computed in this framework. The returned value is an index in the knots table of the BSpline curve analysed by this algorithm. Notes:

  • If Index is equal to 1, the corresponding knot gives the first point of the curve.
  • If Index is equal to the number of split knots computed in this framework, the corresponding point is the last point of the curve. Exceptions Standard_RangeError if Index is less than 1 or greater than the number of split knots computed in this framework.

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