Commit | Line | Data |
---|---|---|

42cf5bc1 | 1 | // Created on: 1993-03-24 |

2 | // Created by: DUB | |

3 | // Copyright (c) 1993-1999 Matra Datavision | |

4 | // Copyright (c) 1999-2014 OPEN CASCADE SAS | |

5 | // | |

6 | // This file is part of Open CASCADE Technology software library. | |

7 | // | |

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. | |

13 | // | |

14 | // Alternatively, this file may be used under the terms of Open CASCADE | |

15 | // commercial license or contractual agreement. | |

16 | ||

17 | #ifndef _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile | |

18 | #define _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile | |

19 | ||

20 | #include <Standard.hxx> | |

21 | #include <Standard_DefineAlloc.hxx> | |

22 | #include <Standard_Handle.hxx> | |

23 | ||

24 | #include <Standard_Real.hxx> | |

25 | #include <Standard_Integer.hxx> | |

26 | #include <TColGeom2d_Array1OfBezierCurve.hxx> | |

27 | #include <TColStd_Array1OfReal.hxx> | |

28 | class Geom2d_BSplineCurve; | |

29 | class Standard_DimensionError; | |

30 | class Standard_DomainError; | |

31 | class Standard_OutOfRange; | |

32 | class Geom2d_BezierCurve; | |

33 | ||

34 | ||

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. | |

41 | //! References : | |

42 | //! Generating the Bezier points of B-spline curves and surfaces | |

43 | //! (Wolfgang Bohm) CAD volume 13 number 6 november 1981 | |

44 | class Geom2dConvert_BSplineCurveToBezierCurve | |

45 | { | |

46 | public: | |

47 | ||

48 | DEFINE_STANDARD_ALLOC | |

49 | ||

50 | ||

51 | //! Computes all the data needed to convert | |

52 | //! - the BSpline curve BasisCurve, into a series of adjacent Bezier arcs. | |

53 | //! The result consists of a series of BasisCurve arcs | |

54 | //! limited by points corresponding to knot values of the curve. | |

55 | //! Use the available interrogation functions to ascertain | |

56 | //! the number of computed Bezier arcs, and then to | |

57 | //! construct each individual Bezier curve (or all Bezier curves). | |

58 | //! Note: ParametricTolerance is not used. | |

59 | Standard_EXPORT Geom2dConvert_BSplineCurveToBezierCurve(const Handle(Geom2d_BSplineCurve)& BasisCurve); | |

60 | ||

61 | //! Computes all the data needed to convert | |

62 | //! the portion of the BSpline curve BasisCurve | |

63 | //! limited by the two parameter values U1 and U2 | |

64 | //! for Example if there is a Knot Uk and | |

65 | //! Uk < U < Uk + ParametricTolerance/2 the last curve | |

66 | //! corresponds to the span [Uk-1, Uk] and not to [Uk, Uk+1] | |

67 | //! The result consists of a series of BasisCurve arcs | |

68 | //! limited by points corresponding to knot values of the curve. | |

69 | //! Use the available interrogation functions to ascertain | |

70 | //! the number of computed Bezier arcs, and then to | |

71 | //! construct each individual Bezier curve (or all Bezier curves). | |

72 | //! Note: ParametricTolerance is not used. | |

73 | //! Raises DomainError if U1 or U2 are out of the parametric bounds of the basis | |

74 | //! curve [FirstParameter, LastParameter]. The Tolerance criterion | |

75 | //! is ParametricTolerance. | |

76 | //! Raised if Abs (U2 - U1) <= ParametricTolerance. | |

77 | Standard_EXPORT Geom2dConvert_BSplineCurveToBezierCurve(const Handle(Geom2d_BSplineCurve)& BasisCurve, const Standard_Real U1, const Standard_Real U2, const Standard_Real ParametricTolerance); | |

78 | ||

79 | //! Constructs and returns the Bezier curve of index | |

80 | //! Index to the table of adjacent Bezier arcs | |

81 | //! computed by this algorithm. | |

82 | //! This Bezier curve has the same orientation as the | |

83 | //! BSpline curve analyzed in this framework. | |

84 | //! Exceptions | |

85 | //! Standard_OutOfRange if Index is less than 1 or | |

86 | //! greater than the number of adjacent Bezier arcs | |

87 | //! computed by this algorithm. | |

88 | Standard_EXPORT Handle(Geom2d_BezierCurve) Arc (const Standard_Integer Index); | |

89 | ||

90 | //! Constructs all the Bezier curves whose data is | |

91 | //! computed by this algorithm and loads these curves | |

92 | //! into the Curves table. | |

93 | //! The Bezier curves have the same orientation as the | |

94 | //! BSpline curve analyzed in this framework. | |

95 | //! Exceptions | |

96 | //! Standard_DimensionError if the Curves array was | |

97 | //! not created with the following bounds: | |

98 | //! - 1 , and | |

99 | //! - the number of adjacent Bezier arcs computed by | |

100 | //! this algorithm (as given by the function NbArcs). | |

101 | Standard_EXPORT void Arcs (TColGeom2d_Array1OfBezierCurve& Curves); | |

102 | ||

103 | //! This methode returns the bspline's knots associated to | |

104 | //! the converted arcs | |

105 | //! Raises DimensionError if the length of Curves is not equal to | |

106 | //! NbArcs + 1 | |

107 | Standard_EXPORT void Knots (TColStd_Array1OfReal& TKnots) const; | |

108 | ||

109 | ||

110 | //! Returns the number of BezierCurve arcs. | |

111 | //! If at the creation time you have decomposed the basis curve | |

112 | //! between the parametric values UFirst, ULast the number of | |

113 | //! BezierCurve arcs depends on the number of knots included inside | |

114 | //! the interval [UFirst, ULast]. | |

115 | //! If you have decomposed the whole basis B-spline curve the number | |

116 | //! of BezierCurve arcs NbArcs is equal to the number of knots less | |

117 | //! one. | |

118 | Standard_EXPORT Standard_Integer NbArcs() const; | |

119 | ||

120 | ||

121 | ||

122 | ||

123 | protected: | |

124 | ||

125 | ||

126 | ||

127 | ||

128 | ||

129 | private: | |

130 | ||

131 | ||

132 | ||

133 | Handle(Geom2d_BSplineCurve) myCurve; | |

134 | ||

135 | ||

136 | }; | |

137 | ||

138 | ||

139 | ||

140 | ||

141 | ||

142 | ||

143 | ||

144 | #endif // _Geom2dConvert_BSplineCurveToBezierCurve_HeaderFile |