// Created on: 1991-10-03
// Copyright (c) 1991-1999 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.
#ifndef _Geom2dConvert_BSplineCurveKnotSplitting_HeaderFile
#define _Geom2dConvert_BSplineCurveKnotSplitting_HeaderFile
#include
#include
#include
#include
#include
#include
class Standard_DimensionError;
class Standard_RangeError;
class Geom2d_BSplineCurve;
//! 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:
//! - defining the curve to be analysed and the required degree of continuity,
//! - implementing the computation algorithm, and
//! - consulting the results.
class Geom2dConvert_BSplineCurveKnotSplitting
{
public:
DEFINE_STANDARD_ALLOC
//! 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.
Standard_EXPORT Geom2dConvert_BSplineCurveKnotSplitting(const Handle(Geom2d_BSplineCurve)& BasisCurve, const Standard_Integer ContinuityRange);
//! 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.
Standard_EXPORT Standard_Integer NbSplits() 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).
Standard_EXPORT void Splitting (TColStd_Array1OfInteger& SplitValues) 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.
Standard_EXPORT Standard_Integer SplitValue (const Standard_Integer Index) const;
protected:
private:
Handle(TColStd_HArray1OfInteger) splitIndexes;
};
#endif // _Geom2dConvert_BSplineCurveKnotSplitting_HeaderFile