1 // Copyright (c) 2014 OPEN CASCADE SAS
3 // This file is part of Open CASCADE Technology software library.
5 // This library is free software; you can redistribute it and/or modify it under
6 // the terms of the GNU Lesser General Public License version 2.1 as published
7 // by the Free Software Foundation, with special exception defined in the file
8 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
9 // distribution for complete text of the license and disclaimer of any warranty.
11 // Alternatively, this file may be used under the terms of Open CASCADE
12 // commercial license or contractual agreement.
14 #ifndef _BSplSLib_Cache_Headerfile
15 #define _BSplSLib_Cache_Headerfile
17 #include <Standard.hxx>
18 #include <Standard_Macro.hxx>
19 #include <Standard_DefineHandle.hxx>
20 #include <Standard_Transient.hxx>
22 #include <Handle_TColStd_HArray1OfReal.hxx>
23 #include <Handle_TColStd_HArray2OfReal.hxx>
28 class Handle(BSplSLib_Cache);
29 class TColgp_Array2OfPnt;
30 class TColStd_Array1OfInteger;
31 class TColStd_Array1OfReal;
32 class TColStd_Array2OfReal;
34 #ifndef NOWEIGHTS_SURF
35 #define NOWEIGHTS_SURF (*((TColStd_Array2OfReal*) NULL))
38 //! \brief A cache class for B-spline surfaces.
40 //! Defines all data, that can be cached on a span of B-spline surface.
41 //! The data should be recalculated in going from span to span.
42 class BSplSLib_Cache : public Standard_Transient
45 //! Default constructor
46 Standard_EXPORT BSplSLib_Cache();
47 //! Constructor for caching of the span for B-spline surface
48 //! \param theDegreeU degree along the first parameter (U) of the B-spline
49 //! \param thePeriodicU identify the B-spline is periodical along U axis
50 //! \param theFlatKnotsU knots of B-spline curve (with repetition) along U axis
51 //! \param theDegreeV degree alogn the second parameter (V) of the B-spline
52 //! \param thePeriodicV identify the B-spline is periodical along V axis
53 //! \param theFlatKnotsV knots of B-spline curve (with repetition) along V axis
54 //! \param thePoles array of poles of the B-spline surface
55 //! \param theWeights array of weights of corresponding poles
56 Standard_EXPORT BSplSLib_Cache(const Standard_Integer& theDegreeU,
57 const Standard_Boolean& thePeriodicU,
58 const TColStd_Array1OfReal& theFlatKnotsU,
59 const Standard_Integer& theDegreeV,
60 const Standard_Boolean& thePeriodicV,
61 const TColStd_Array1OfReal& theFlatKnotsV,
62 const TColgp_Array2OfPnt& thePoles,
63 const TColStd_Array2OfReal& theWeights = NOWEIGHTS_SURF);
65 //! Verifies validity of the cache using parameters of the point
66 //! \param theParameterU first parameter of the point placed in the span
67 //! \param theParameterV second parameter of the point placed in the span
68 Standard_EXPORT Standard_Boolean IsCacheValid(Standard_Real theParameterU,
69 Standard_Real theParameterV) const;
71 //! Recomputes the cache data. Does not verify validity of the cache
72 //! \param theParameterU the parametric value on the U axis to identify the span
73 //! \param theParameterV the parametric value on the V axis to identify the span
74 //! \param theDegreeU degree of the B-spline along U axis
75 //! \param thePeriodicU identify the B-spline is periodic along U axis
76 //! \param theFlatKnotsU flat knots of B-spline surface along U axis
77 //! \param theDegreeV degree of the B-spline along V axis
78 //! \param thePeriodicV identify the B-spline is periodic along V axis
79 //! \param theFlatKnotsV flat knots of B-spline surface along V axis
80 //! \param thePoles array of poles of B-spline
81 //! \param theWeights array of weights of corresponding poles
82 Standard_EXPORT void BuildCache(const Standard_Real& theParameterU,
83 const Standard_Real& theParameterV,
84 const Standard_Integer& theDegreeU,
85 const Standard_Boolean& thePeriodicU,
86 const TColStd_Array1OfReal& theFlatKnotsU,
87 const Standard_Integer& theDegreeV,
88 const Standard_Boolean& thePeriodicV,
89 const TColStd_Array1OfReal& theFlatKnotsV,
90 const TColgp_Array2OfPnt& thePoles,
91 const TColStd_Array2OfReal& theWeights = NOWEIGHTS_SURF);
93 //! Calculates the point on B-spline for specified parameters
94 //! \param[in] theU first parameter for calculation of the value
95 //! \param[in] theV second parameter for calculation of the value
96 //! \param[out] thePoint the result of calculation (the point on the B-spline)
97 Standard_EXPORT void D0(const Standard_Real& theU, const Standard_Real& theV, gp_Pnt& thePoint) const;
99 //! Calculates the point on B-spline and its first derivative
100 //! \param[in] theU first parameter of calculation of the value
101 //! \param[in] theV second parameter of calculation of the value
102 //! \param[out] thePoint the result of calculation (the point on the B-spline)
103 //! \param[out] theTangentU tangent vector along U axis in the calculated point
104 //! \param[out] theTangentV tangent vector along V axis in the calculated point
105 Standard_EXPORT void D1(const Standard_Real& theU,
106 const Standard_Real& theV,
109 gp_Vec& theTangentV) const;
111 //! Calculates the point on B-spline and derivatives till second order
112 //! \param[in] theU first parameter of calculation of the value
113 //! \param[in] theV second parameter of calculation of the value
114 //! \param[out] thePoint the result of calculation (the point on B-spline)
115 //! \param[out] theTangentU tangent vector along U axis in the calculated point
116 //! \param[out] theTangentV tangent vector along V axis in the calculated point
117 //! \param[out] theCurvatureU curvature vector (2nd derivative on U) along U axis
118 //! \param[out] theCurvatureV curvature vector (2nd derivative on V) along V axis
119 //! \param[out] theCurvatureUV 2nd mixed derivative on U anv V
120 Standard_EXPORT void D2(const Standard_Real& theU,
121 const Standard_Real& theV,
125 gp_Vec& theCurvatureU,
126 gp_Vec& theCurvatureV,
127 gp_Vec& theCurvatureUV) const;
130 DEFINE_STANDARD_RTTI(BSplSLib_Cache)
133 //! Normalizes the parameter for periodical B-splines
134 //! \param[in] theDegree degree of B-spline along selected direction
135 //! \param[in] theFlatKnots knots with repetitions along selected direction
136 //! \param[in,out] theParameter the value to be normalized into the knots array
137 void PeriodicNormalization(const Standard_Integer& theDegree,
138 const TColStd_Array1OfReal& theFlatKnots,
139 Standard_Real& theParameter) const;
142 Handle(TColStd_HArray2OfReal) myPolesWeights; ///< array of poles and weights of calculated cache
143 // the array has following structure:
144 // x11 y11 z11 [w11] x12 y12 z12 [w12] ...
145 // x21 y21 z21 [w21] x22 y22 z22 [w22] etc
146 // for non-rational surfaces there is no weight;
147 // size of array: (max(myDegree)+1) * A*(min(myDegree)+1), where A = 4 or 3
149 Standard_Boolean myIsRational; ///< identifies the rationality of B-spline
150 Standard_Real mySpanStart[2]; ///< parameters (u, v) for the frst point of the span
151 Standard_Real mySpanLength[2]; ///< lengths of the span along corresponding parameter
152 Standard_Integer mySpanIndex[2]; ///< indexes of the span on B-spline surface
153 Standard_Integer mySpanIndexMax[2]; ///< maximal indexes of span
154 Standard_Integer myDegree[2]; ///< degrees of B-spline for each parameter
155 Handle(TColStd_HArray1OfReal) myFlatKnots[2]; ///< arrays of knots of B-spline
156 // (used for periodic normalization of parameters, Null for non-periodical splines)
159 DEFINE_STANDARD_HANDLE(BSplSLib_Cache, Standard_Transient)