// Created on: 1993-10-20 // Created by: Bruno DUMORTIER // Copyright (c) 1993-1999 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 _Convert_CompBezierCurvesToBSplineCurve_HeaderFile #define _Convert_CompBezierCurvesToBSplineCurve_HeaderFile #include #include #include #include #include #include #include #include #include //! An algorithm to convert a sequence of adjacent //! non-rational Bezier curves into a BSpline curve. //! A CompBezierCurvesToBSplineCurve object provides a framework for: //! - defining the sequence of adjacent non-rational Bezier //! curves to be converted into a BSpline curve, //! - implementing the computation algorithm, and //! - consulting the results. //! Warning //! Do not attempt to convert rational Bezier curves using this type of algorithm. class Convert_CompBezierCurvesToBSplineCurve { public: DEFINE_STANDARD_ALLOC //! Constructs a framework for converting a sequence of //! adjacent non-rational Bezier curves into a BSpline curve. //! Knots will be created on the computed BSpline curve at //! each junction point of two consecutive Bezier curves. The //! degree of continuity of the BSpline curve will be increased at //! the junction point of two consecutive Bezier curves if their //! tangent vectors at this point are parallel. AngularTolerance //! (given in radians, and defaulted to 1.0 e-4) will be used //! to check the parallelism of the two tangent vectors. //! Use the following functions: //! - AddCurve to define in sequence the adjacent Bezier //! curves to be converted, //! - Perform to compute the data needed to build the BSpline curve, //! - and the available consultation functions to access the //! computed data. This data may be used to construct the BSpline curve. Standard_EXPORT Convert_CompBezierCurvesToBSplineCurve(const Standard_Real AngularTolerance = 1.0e-4); //! Adds the Bezier curve defined by the table of poles Poles, to //! the sequence (still contained in this framework) of adjacent //! Bezier curves to be converted into a BSpline curve. //! Only polynomial (i.e. non-rational) Bezier curves are //! converted using this framework. //! If this is not the first call to the function (i.e. if this framework //! still contains data in its Bezier curve sequence), the degree //! of continuity of the BSpline curve will be increased at the //! time of computation at the first point of the added Bezier //! curve (i.e. the first point of the Poles table). This will be the //! case if the tangent vector of the curve at this point is //! parallel to the tangent vector at the end point of the //! preceding Bezier curve in the Bezier curve sequence still //! contained in this framework. An angular tolerance given at //! the time of construction of this framework will be used to //! check the parallelism of the two tangent vectors. This //! checking procedure and all related computations will be //! performed by the Perform function. //! When the adjacent Bezier curve sequence is complete, use //! the following functions: //! - Perform to compute the data needed to build the BSpline curve, //! - and the available consultation functions to access the //! computed data. This data may be used to construct the BSpline curve. //! Warning //! The Bezier curve sequence treated by this framework is //! automatically initialized with the first Bezier curve when the //! function is first called. During subsequent use of this function, //! ensure that the first point of the added Bezier curve (i.e. the //! first point of the Poles table) is coincident with the last point //! of the Bezier curve sequence (i.e. the last point of the //! preceding Bezier curve in the sequence) still contained in //! this framework. An error may occur at the time of //! computation if this condition is not satisfied. Particular care //! must be taken with respect to the above, as this condition is //! not checked either when defining the Bezier curve //! sequence or at the time of computation. Standard_EXPORT void AddCurve (const TColgp_Array1OfPnt& Poles); //! Computes all the data needed to build a BSpline curve //! equivalent to the adjacent Bezier curve sequence still //! contained in this framework. //! A knot is inserted on the computed BSpline curve at the //! junction point of two consecutive Bezier curves. The //! degree of continuity of the BSpline curve will be increased //! at the junction point of two consecutive Bezier curves if //! their tangent vectors at this point are parallel. An angular //! tolerance given at the time of construction of this //! framework is used to check the parallelism of the two //! tangent vectors. //! Use the available consultation functions to access the //! computed data. This data may then be used to construct //! the BSpline curve. //! Warning //! Make sure that the curves in the Bezier curve sequence //! contained in this framework are adjacent. An error may //! occur at the time of computation if this condition is not //! satisfied. Particular care must be taken with respect to the //! above as this condition is not checked, either when //! defining the Bezier curve sequence or at the time of computation. Standard_EXPORT void Perform(); //! Returns the degree of the BSpline curve whose data is //! computed in this framework. //! Warning //! Take particular care not to use this function before the //! computation is performed (Perform function), as this //! condition is not checked and an error may therefore occur. Standard_EXPORT Standard_Integer Degree() const; //! Returns the number of poles of the BSpline curve whose //! data is computed in this framework. //! Warning //! Take particular care not to use this function before the //! computation is performed (Perform function), as this //! condition is not checked and an error may therefore occur. Standard_EXPORT Standard_Integer NbPoles() const; //! Loads the Poles table with the poles of the BSpline curve //! whose data is computed in this framework. //! Warning //! - Do not use this function before the computation is //! performed (Perform function). //! - The length of the Poles array must be equal to the //! number of poles of the BSpline curve whose data is //! computed in this framework. //! Particular care must be taken with respect to the above, as //! these conditions are not checked, and an error may occur. Standard_EXPORT void Poles (TColgp_Array1OfPnt& Poles) const; //! Returns the number of knots of the BSpline curve whose //! data is computed in this framework. //! Warning //! Take particular care not to use this function before the //! computation is performed (Perform function), as this //! condition is not checked and an error may therefore occur. Standard_EXPORT Standard_Integer NbKnots() const; //! - loads the Knots table with the knots, //! - and loads the Mults table with the corresponding multiplicities //! of the BSpline curve whose data is computed in this framework. //! Warning //! - Do not use this function before the computation is //! performed (Perform function). //! - The length of the Knots and Mults arrays must be equal //! to the number of knots in the BSpline curve whose data is //! computed in this framework. //! Particular care must be taken with respect to the above as //! these conditions are not checked, and an error may occur. Standard_EXPORT void KnotsAndMults (TColStd_Array1OfReal& Knots, TColStd_Array1OfInteger& Mults) const; protected: private: Convert_SequenceOfArray1OfPoles mySequence; TColgp_SequenceOfPnt CurvePoles; TColStd_SequenceOfReal CurveKnots; TColStd_SequenceOfInteger KnotsMultiplicities; Standard_Integer myDegree; Standard_Real myAngular; Standard_Boolean myDone; }; #endif // _Convert_CompBezierCurvesToBSplineCurve_HeaderFile