// Created on: 1996-03-12 // Created by: Bruno DUMORTIER // Copyright (c) 1996-1999 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 _GeomConvert_BSplineSurfaceToBezierSurface_HeaderFile #define _GeomConvert_BSplineSurfaceToBezierSurface_HeaderFile #include #include #include #include #include #include #include class Geom_BSplineSurface; class Geom_BezierSurface; //! This algorithm converts a B-spline surface into several //! Bezier surfaces. It uses an algorithm of knot insertion. //! A BSplineSurfaceToBezierSurface object provides a framework for: //! - defining the BSpline surface to be converted, //! - implementing the construction algorithm, and //! - consulting the results. //! References : //! Generating the Bezier points of B-spline curves and surfaces //! (Wolfgang Bohm) CAD volume 13 number 6 november 1981 class GeomConvert_BSplineSurfaceToBezierSurface { public: DEFINE_STANDARD_ALLOC //! Computes all the data needed to convert //! - the BSpline surface BasisSurface into a series of adjacent Bezier surfaces. //! The result consists of a grid of BasisSurface patches //! limited by isoparametric curves corresponding to knot //! values, both in the u and v parametric directions of //! the surface. A row in the grid corresponds to a series //! of adjacent patches, all limited by the same two //! u-isoparametric curves. A column in the grid //! corresponds to a series of adjacent patches, all //! limited by the same two v-isoparametric curves. //! Use the available interrogation functions to ascertain //! the number of computed Bezier patches, and then to //! construct each individual Bezier surface (or all Bezier surfaces). //! Note: ParametricTolerance is not used. Standard_EXPORT GeomConvert_BSplineSurfaceToBezierSurface(const Handle(Geom_BSplineSurface)& BasisSurface); //! Computes all the data needed to convert //! the patch of the BSpline surface BasisSurface //! limited by the two parameter values U1 and U2 in //! the u parametric direction, and by the two //! parameter values V1 and V2 in the v parametric //! direction, into a series of adjacent Bezier surfaces. //! The result consists of a grid of BasisSurface patches //! limited by isoparametric curves corresponding to knot //! values, both in the u and v parametric directions of //! the surface. A row in the grid corresponds to a series //! of adjacent patches, all limited by the same two //! u-isoparametric curves. A column in the grid //! corresponds to a series of adjacent patches, all //! limited by the same two v-isoparametric curves. //! Use the available interrogation functions to ascertain //! the number of computed Bezier patches, and then to //! construct each individual Bezier surface (or all Bezier surfaces). //! Note: ParametricTolerance is not used. Raises DomainError //! if U1 or U2 or V1 or V2 are out of the parametric bounds //! of the basis surface [FirstUKnotIndex, LastUKnotIndex] , //! [FirstVKnotIndex, LastVKnotIndex] The tolerance criterion is //! ParametricTolerance. //! Raised if U2 - U1 <= ParametricTolerance or //! V2 - V1 <= ParametricTolerance. Standard_EXPORT GeomConvert_BSplineSurfaceToBezierSurface(const Handle(Geom_BSplineSurface)& BasisSurface, const Standard_Real U1, const Standard_Real U2, const Standard_Real V1, const Standard_Real V2, const Standard_Real ParametricTolerance); //! Constructs and returns the Bezier surface of indices //! (UIndex, VIndex) to the patch grid computed on the //! BSpline surface analyzed by this algorithm. //! This Bezier surface has the same orientation as the //! BSpline surface analyzed in this framework. //! UIndex is an index common to a row in the patch //! grid. A row in the grid corresponds to a series of //! adjacent patches, all limited by the same two //! u-isoparametric curves of the surface. VIndex is an //! index common to a column in the patch grid. A column //! in the grid corresponds to a series of adjacent //! patches, all limited by the same two v-isoparametric //! curves of the surface. //! Exceptions //! Standard_OutOfRange if: //! - UIndex is less than 1 or greater than the number //! of rows in the patch grid computed on the BSpline //! surface analyzed by this algorithm (as returned by //! the function NbUPatches); or if //! - VIndex is less than 1 or greater than the number //! of columns in the patch grid computed on the //! BSpline surface analyzed by this algorithm (as //! returned by the function NbVPatches). Standard_EXPORT Handle(Geom_BezierSurface) Patch (const Standard_Integer UIndex, const Standard_Integer VIndex); //! Constructs all the Bezier surfaces whose data is //! computed by this algorithm, and loads them into the Surfaces table. //! These Bezier surfaces have the same orientation as //! the BSpline surface analyzed in this framework. //! The Surfaces array is organised in the same way as //! the patch grid computed on the BSpline surface //! analyzed by this algorithm. A row in the array //! corresponds to a series of adjacent patches, all //! limited by the same two u-isoparametric curves of //! the surface. A column in the array corresponds to a //! series of adjacent patches, all limited by the same two //! v-isoparametric curves of the surface. //! Exceptions //! Standard_DimensionError if the Surfaces array //! was not created with the following bounds: //! - 1, and the number of adjacent patch series in the //! u parametric direction of the patch grid computed //! on the BSpline surface, analyzed by this algorithm //! (as given by the function NbUPatches) as row bounds, //! - 1, and the number of adjacent patch series in the //! v parametric direction of the patch grid computed //! on the BSpline surface, analyzed by this algorithm //! (as given by the function NbVPatches) as column bounds. Standard_EXPORT void Patches (TColGeom_Array2OfBezierSurface& Surfaces); //! This methode returns the bspline's u-knots associated to //! the converted Patches //! Raised if the length of Curves is not equal to //! NbUPatches + 1. Standard_EXPORT void UKnots (TColStd_Array1OfReal& TKnots) const; //! This methode returns the bspline's v-knots associated to //! the converted Patches //! Raised if the length of Curves is not equal to //! NbVPatches + 1. Standard_EXPORT void VKnots (TColStd_Array1OfReal& TKnots) const; //! Returns the number of Bezier surfaces in the U direction. //! If at the creation time you have decomposed the basis Surface //! between the parametric values UFirst, ULast the number of //! Bezier surfaces in the U direction depends on the number of //! knots included inside the interval [UFirst, ULast]. //! If you have decomposed the whole basis B-spline surface the //! number of Bezier surfaces NbUPatches is equal to the number of //! UKnots less one. Standard_EXPORT Standard_Integer NbUPatches() const; //! Returns the number of Bezier surfaces in the V direction. //! If at the creation time you have decomposed the basis surface //! between the parametric values VFirst, VLast the number of //! Bezier surfaces in the V direction depends on the number of //! knots included inside the interval [VFirst, VLast]. //! If you have decomposed the whole basis B-spline surface the //! number of Bezier surfaces NbVPatches is equal to the number of //! VKnots less one. Standard_EXPORT Standard_Integer NbVPatches() const; protected: private: Handle(Geom_BSplineSurface) mySurface; }; #endif // _GeomConvert_BSplineSurfaceToBezierSurface_HeaderFile