1 // Created on: 1996-03-12
2 // Created by: Bruno DUMORTIER
3 // Copyright (c) 1996-1999 Matra Datavision
4 // Copyright (c) 1999-2014 OPEN CASCADE SAS
6 // This file is part of Open CASCADE Technology software library.
8 // This library is free software; you can redistribute it and/or modify it under
9 // the terms of the GNU Lesser General Public License version 2.1 as published
10 // by the Free Software Foundation, with special exception defined in the file
11 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
12 // distribution for complete text of the license and disclaimer of any warranty.
14 // Alternatively, this file may be used under the terms of Open CASCADE
15 // commercial license or contractual agreement.
17 #ifndef _GeomConvert_BSplineCurveToBezierCurve_HeaderFile
18 #define _GeomConvert_BSplineCurveToBezierCurve_HeaderFile
20 #include <Standard.hxx>
21 #include <Standard_DefineAlloc.hxx>
22 #include <Standard_Handle.hxx>
24 #include <Standard_Real.hxx>
25 #include <Standard_Integer.hxx>
26 #include <TColGeom_Array1OfBezierCurve.hxx>
27 #include <TColStd_Array1OfReal.hxx>
28 class Geom_BSplineCurve;
29 class Standard_DimensionError;
30 class Standard_DomainError;
31 class Standard_OutOfRange;
32 class Geom_BezierCurve;
35 //! An algorithm to convert a BSpline curve into a series
36 //! of adjacent Bezier curves.
37 //! A BSplineCurveToBezierCurve object provides a framework for:
38 //! - defining the BSpline curve to be converted
39 //! - implementing the construction algorithm, and
40 //! - consulting the results.
42 //! Generating the Bezier points of B-spline curves and surfaces
43 //! (Wolfgang Bohm) CAD volume 13 number 6 november 1981
44 class GeomConvert_BSplineCurveToBezierCurve
51 //! Computes all the data needed to convert the
52 //! BSpline curve BasisCurve into a series of adjacent Bezier arcs.
53 Standard_EXPORT GeomConvert_BSplineCurveToBezierCurve(const Handle(Geom_BSplineCurve)& BasisCurve);
55 //! Computes all the data needed to convert
56 //! the portion of the BSpline curve BasisCurve
57 //! limited by the two parameter values U1 and U2 into a series of adjacent Bezier arcs.
58 //! The result consists of a series of BasisCurve arcs
59 //! limited by points corresponding to knot values of the curve.
60 //! Use the available interrogation functions to ascertain
61 //! the number of computed Bezier arcs, and then to
62 //! construct each individual Bezier curve (or all Bezier curves).
63 //! Note: ParametricTolerance is not used.
64 //! Raises DomainError if U1 or U2 are out of the parametric bounds of the basis
65 //! curve [FirstParameter, LastParameter]. The Tolerance criterion
66 //! is ParametricTolerance.
67 //! Raised if Abs (U2 - U1) <= ParametricTolerance.
68 Standard_EXPORT GeomConvert_BSplineCurveToBezierCurve(const Handle(Geom_BSplineCurve)& BasisCurve, const Standard_Real U1, const Standard_Real U2, const Standard_Real ParametricTolerance);
70 //! Constructs and returns the Bezier curve of index
71 //! Index to the table of adjacent Bezier arcs
72 //! computed by this algorithm.
73 //! This Bezier curve has the same orientation as the
74 //! BSpline curve analyzed in this framework.
76 //! Standard_OutOfRange if Index is less than 1 or
77 //! greater than the number of adjacent Bezier arcs
78 //! computed by this algorithm.
79 Standard_EXPORT Handle(Geom_BezierCurve) Arc (const Standard_Integer Index);
81 //! Constructs all the Bezier curves whose data is
82 //! computed by this algorithm and loads these curves into the Curves table.
83 //! The Bezier curves have the same orientation as the
84 //! BSpline curve analyzed in this framework.
86 //! Standard_DimensionError if the Curves array was
87 //! not created with the following bounds:
89 //! - the number of adjacent Bezier arcs computed by
90 //! this algorithm (as given by the function NbArcs).
91 Standard_EXPORT void Arcs (TColGeom_Array1OfBezierCurve& Curves);
93 //! This methode returns the bspline's knots associated to
94 //! the converted arcs
95 //! Raised if the length of Curves is not equal to
97 Standard_EXPORT void Knots (TColStd_Array1OfReal& TKnots) const;
100 //! Returns the number of BezierCurve arcs.
101 //! If at the creation time you have decomposed the basis curve
102 //! between the parametric values UFirst, ULast the number of
103 //! BezierCurve arcs depends on the number of knots included inside
104 //! the interval [UFirst, ULast].
105 //! If you have decomposed the whole basis B-spline curve the number
106 //! of BezierCurve arcs NbArcs is equal to the number of knots less
108 Standard_EXPORT Standard_Integer NbArcs() const;
123 Handle(Geom_BSplineCurve) myCurve;
134 #endif // _GeomConvert_BSplineCurveToBezierCurve_HeaderFile