Geom2dConvert_BSplineCurveToBezierCurve Class Reference

An algorithm to convert a BSpline curve into a series of adjacent Bezier curves. A BSplineCurveToBezierCurve object provides a framework for: More...

#include <Geom2dConvert_BSplineCurveToBezierCurve.hxx>

Public Member Functions
	Geom2dConvert_BSplineCurveToBezierCurve (const Handle< Geom2d_BSplineCurve > &BasisCurve)
	Computes all the data needed to convert. More...
	Geom2dConvert_BSplineCurveToBezierCurve (const Handle< Geom2d_BSplineCurve > &BasisCurve, const Standard_Real U1, const Standard_Real U2, const Standard_Real ParametricTolerance)
	Computes all the data needed to convert the portion of the BSpline curve BasisCurve limited by the two parameter values U1 and U2 for Example if there is a Knot Uk and Uk < U < Uk + ParametricTolerance/2 the last curve corresponds to the span [Uk-1, Uk] and not to [Uk, Uk+1] The result consists of a series of BasisCurve arcs limited by points corresponding to knot values of the curve. Use the available interrogation functions to ascertain the number of computed Bezier arcs, and then to construct each individual Bezier curve (or all Bezier curves). Note: ParametricTolerance is not used. Raises DomainError if U1 or U2 are out of the parametric bounds of the basis curve [FirstParameter, LastParameter]. The Tolerance criterion is ParametricTolerance. Raised if Abs (U2 - U1) <= ParametricTolerance. More...
Handle< Geom2d_BezierCurve >	Arc (const Standard_Integer Index)
	Constructs and returns the Bezier curve of index Index to the table of adjacent Bezier arcs computed by this algorithm. This Bezier curve has the same orientation as the BSpline curve analyzed in this framework. Exceptions Standard_OutOfRange if Index is less than 1 or greater than the number of adjacent Bezier arcs computed by this algorithm. More...
void	Arcs (TColGeom2d_Array1OfBezierCurve &Curves)
	Constructs all the Bezier curves whose data is computed by this algorithm and loads these curves into the Curves table. The Bezier curves have the same orientation as the BSpline curve analyzed in this framework. Exceptions Standard_DimensionError if the Curves array was not created with the following bounds: More...
void	Knots (TColStd_Array1OfReal &TKnots) const
	This methode returns the bspline's knots associated to the converted arcs Raises DimensionError if the length of Curves is not equal to NbArcs + 1. More...
Standard_Integer	NbArcs () const
	Returns the number of BezierCurve arcs. If at the creation time you have decomposed the basis curve between the parametric values UFirst, ULast the number of BezierCurve arcs depends on the number of knots included inside the interval [UFirst, ULast]. If you have decomposed the whole basis B-spline curve the number of BezierCurve arcs NbArcs is equal to the number of knots less one. More...

Detailed Description

An algorithm to convert a BSpline curve into a series of adjacent Bezier curves. A BSplineCurveToBezierCurve object provides a framework for:

• defining the BSpline curve to be converted
• implementing the construction algorithm, and
• consulting the results. References : Generating the Bezier points of B-spline curves and surfaces (Wolfgang Bohm) CAD volume 13 number 6 november 1981

Constructor & Destructor Documentation

Geom2dConvert_BSplineCurveToBezierCurve() [1/2]

Geom2dConvert_BSplineCurveToBezierCurve::Geom2dConvert_BSplineCurveToBezierCurve

(

const Handle< Geom2d_BSplineCurve > &

BasisCurve

)

Computes all the data needed to convert.

• the BSpline curve BasisCurve, into a series of adjacent Bezier arcs. The result consists of a series of BasisCurve arcs limited by points corresponding to knot values of the curve. Use the available interrogation functions to ascertain the number of computed Bezier arcs, and then to construct each individual Bezier curve (or all Bezier curves). Note: ParametricTolerance is not used.

Geom2dConvert_BSplineCurveToBezierCurve() [2/2]

Geom2dConvert_BSplineCurveToBezierCurve::Geom2dConvert_BSplineCurveToBezierCurve	(	const Handle< Geom2d_BSplineCurve > &	BasisCurve,
		const Standard_Real	U1,
		const Standard_Real	U2,
		const Standard_Real	ParametricTolerance
	)

Computes all the data needed to convert the portion of the BSpline curve BasisCurve limited by the two parameter values U1 and U2 for Example if there is a Knot Uk and Uk < U < Uk + ParametricTolerance/2 the last curve corresponds to the span [Uk-1, Uk] and not to [Uk, Uk+1] The result consists of a series of BasisCurve arcs limited by points corresponding to knot values of the curve. Use the available interrogation functions to ascertain the number of computed Bezier arcs, and then to construct each individual Bezier curve (or all Bezier curves). Note: ParametricTolerance is not used. Raises DomainError if U1 or U2 are out of the parametric bounds of the basis curve [FirstParameter, LastParameter]. The Tolerance criterion is ParametricTolerance. Raised if Abs (U2 - U1) <= ParametricTolerance.

Member Function Documentation

Arc()

Handle< Geom2d_BezierCurve > Geom2dConvert_BSplineCurveToBezierCurve::Arc

(

const Standard_Integer

Index

)

Constructs and returns the Bezier curve of index Index to the table of adjacent Bezier arcs computed by this algorithm. This Bezier curve has the same orientation as the BSpline curve analyzed in this framework. Exceptions Standard_OutOfRange if Index is less than 1 or greater than the number of adjacent Bezier arcs computed by this algorithm.

Arcs()

void Geom2dConvert_BSplineCurveToBezierCurve::Arcs

(

TColGeom2d_Array1OfBezierCurve &

Curves

)

Constructs all the Bezier curves whose data is computed by this algorithm and loads these curves into the Curves table. The Bezier curves have the same orientation as the BSpline curve analyzed in this framework. Exceptions Standard_DimensionError if the Curves array was not created with the following bounds:

• 1 , and
• the number of adjacent Bezier arcs computed by this algorithm (as given by the function NbArcs).

Knots()

void Geom2dConvert_BSplineCurveToBezierCurve::Knots

(

TColStd_Array1OfReal &

TKnots

)

const

This methode returns the bspline's knots associated to the converted arcs Raises DimensionError if the length of Curves is not equal to NbArcs + 1.

NbArcs()

Standard_Integer Geom2dConvert_BSplineCurveToBezierCurve::NbArcs

(

)

const

Returns the number of BezierCurve arcs. If at the creation time you have decomposed the basis curve between the parametric values UFirst, ULast the number of BezierCurve arcs depends on the number of knots included inside the interval [UFirst, ULast]. If you have decomposed the whole basis B-spline curve the number of BezierCurve arcs NbArcs is equal to the number of knots less one.

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

• Geom2dConvert_BSplineCurveToBezierCurve.hxx