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42cf5bc1 1// Created on: 1997-05-13
2// Created by: Stagiaire Francois DUMONT
3// Copyright (c) 1997-1999 Matra Datavision
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
19
20#include <Standard.hxx>
21#include <Standard_DefineAlloc.hxx>
22#include <Standard_Handle.hxx>
23
24#include <TColStd_Array1OfReal.hxx>
25#include <Standard_Real.hxx>
26class Geom_BSplineSurface;
27class Standard_OutOfRange;
28class Standard_ConstructionError;
29
30
31//! this defines an evaluator for a function of 2 variables
32//! that will be used by CancelDenominatorDerivative in one
33//! direction.
34class GeomLib_DenominatorMultiplier
35{
36public:
37
38 DEFINE_STANDARD_ALLOC
39
40
41 //! if the surface is rational this will define the evaluator
42 //! of a real function of 2 variables a(u,v) such that
43 //! if we define a new surface by :
44 //! a(u,v) * N(u,v)
45 //! NewF(u,v) = ----------------
46 //! a(u,v) * D(u,v)
47 Standard_EXPORT GeomLib_DenominatorMultiplier(const Handle(Geom_BSplineSurface)& Surface, const TColStd_Array1OfReal& KnotVector);
48
49 //! Returns the value of
50 //! a(UParameter,VParameter)=
51 //!
52 //! H0(UParameter)/Denominator(Umin,Vparameter)
53 //!
54 //! D Denominator(Umin,Vparameter)
55 //! - ------------------------------[H1(u)]/(Denominator(Umin,Vparameter)^2)
56 //! D U
57 //!
58 //! + H3(UParameter)/Denominator(Umax,Vparameter)
59 //!
60 //! D Denominator(Umax,Vparameter)
61 //! - ------------------------------[H2(u)]/(Denominator(Umax,Vparameter)^2)
62 //! D U
63 Standard_EXPORT Standard_Real Value (const Standard_Real UParameter, const Standard_Real VParameter) const;
64
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67
68protected:
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72
73
74private:
75
76
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78 Handle(Geom_BSplineSurface) mySurface;
79 TColStd_Array1OfReal myKnotFlatVector;
80
81
82};
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