EIC code displayed by LXR master/​include/​opencascade/​GeomConvert_BSplineSurfaceKnotSplitting.hxx	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-06-28 08:16:26

 // Created on: 1991-10-04
 // Copyright (c) 1991-1999 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_BSplineSurfaceKnotSplitting_HeaderFile
 #define _GeomConvert_BSplineSurfaceKnotSplitting_HeaderFile
 
 #include <Standard.hxx>
 #include <Standard_DefineAlloc.hxx>
 #include <Standard_Handle.hxx>
 
 #include <TColStd_HArray1OfInteger.hxx>
 #include <Standard_Integer.hxx>
 #include <TColStd_Array1OfInteger.hxx>
 class Geom_BSplineSurface;
 
 //! An algorithm to determine isoparametric curves along
 //! which a BSpline surface should be split in order to
 //! obtain patches of the same continuity. The continuity order is given at the
 //! construction time. It is possible to compute the surface patches
 //! corresponding to the splitting with the method of package
 //! SplitBSplineSurface.
 //! For a B-spline surface the discontinuities are localised at
 //! the knot values. Between two knots values the B-spline is
 //! infinitely continuously differentiable.  For each parametric
 //! direction at a knot of range index the continuity in this
 //! direction is equal to :  Degree - Mult (Index)   where  Degree
 //! is the degree of the basis B-spline functions and Mult the
 //! multiplicity of the knot of range Index in the given direction.
 //! If for your computation you need to have B-spline surface with a
 //! minima of continuity it can be interesting to know between which
 //! knot values, a B-spline patch, has a continuity of given order.
 //! This algorithm computes the indexes of the knots where you should
 //! split the surface, to obtain patches with a constant continuity
 //! given at the construction time. If you just want to compute the
 //! local derivatives on the surface you don't need to create the
 //! BSpline patches, you can use the functions LocalD1, LocalD2,
 //! LocalD3, LocalDN of the class BSplineSurface from package Geom.
 class GeomConvert_BSplineSurfaceKnotSplitting
 {
 public:
   DEFINE_STANDARD_ALLOC
 
   //! Determines the u- and v-isoparametric curves
   //! along which the BSpline surface BasisSurface
   //! should be split in order to obtain patches with a
   //! degree of continuity equal to UContinuityRange in
   //! the u parametric direction, and to
   //! VContinuityRange in the v parametric direction.
   //! These isoparametric curves are defined by
   //! parameters, which are BasisSurface knot values in
   //! the u or v parametric direction. They are identified
   //! by indices in the BasisSurface knots table in the
   //! corresponding parametric direction.
   //! Use the available interrogation functions to access
   //! computed values, followed by the global function
   //! SplitBSplineSurface (provided by the package
   //! GeomConvert) to split the surface.
   //! Exceptions
   //! Standard_RangeError if UContinuityRange or
   //! VContinuityRange is less than zero.
   Standard_EXPORT GeomConvert_BSplineSurfaceKnotSplitting(
     const Handle(Geom_BSplineSurface)& BasisSurface,
     const Standard_Integer             UContinuityRange,
     const Standard_Integer             VContinuityRange);
 
   //! Returns the number of u-isoparametric curves
   //! along which the analysed BSpline surface should be
   //! split in order to obtain patches with the continuity
   //! required by this framework.
   //! The parameters which define these curves are knot
   //! values in the corresponding parametric direction.
   //! Note that the four curves which bound the surface are
   //! counted among these splitting curves.
   Standard_EXPORT Standard_Integer NbUSplits() const;
 
   //! Returns the number of v-isoparametric curves
   //! along which the analysed BSpline surface should be
   //! split in order to obtain patches with the continuity
   //! required by this framework.
   //! The parameters which define these curves are knot
   //! values in the corresponding parametric direction.
   //! Note that the four curves which bound the surface are
   //! counted among these splitting curves.
   Standard_EXPORT Standard_Integer NbVSplits() const;
 
   //! Loads the USplit and VSplit tables with the split
   //! knots values computed in this framework. Each value
   //! in these tables is an index in the knots table
   //! corresponding to the u or v parametric direction of
   //! the BSpline surface analysed by this algorithm.
   //! The USplit and VSplit values are given in ascending
   //! order and comprise the indices of the knots which
   //! give the first and last isoparametric curves of the
   //! surface in the corresponding parametric direction.
   //! Use two consecutive values from the USplit table and
   //! two consecutive values from the VSplit table as
   //! arguments of the global function
   //! SplitBSplineSurface (provided by the package
   //! GeomConvert) to split the surface.
   //! Exceptions
   //! Standard_DimensionError if:
   //! -   the array USplit was not created with the following bounds:
   //! -   1 , and
   //! -   the number of split knots in the u parametric
   //! direction computed in this framework (as given
   //! by the function NbUSplits); or
   //! -   the array VSplit was not created with the following bounds:
   //! -   1 , and
   //! -   the number of split knots in the v parametric
   //! direction computed in this framework (as given
   //! by the function NbVSplits).
   Standard_EXPORT void Splitting(TColStd_Array1OfInteger& USplit,
                                  TColStd_Array1OfInteger& VSplit) const;
 
   //! Returns the split knot of index UIndex
   //! to the split knots table for the u  parametric direction
   //! computed in this framework. The returned value is
   //! an index in the knots table relative to the u
   //! parametric direction of the BSpline surface analysed by this algorithm.
   //! Note: If UIndex is equal to 1, or to the number of split knots for the u
   //! parametric direction computed in
   //! this framework, the corresponding knot gives the
   //! parameter of one of the bounding curves of the surface.
   //! Exceptions
   //! Standard_RangeError if UIndex  is less than 1 or greater than the number
   //! of split knots for the u parametric direction computed in this framework.
   Standard_EXPORT Standard_Integer USplitValue(const Standard_Integer UIndex) const;
 
   //! Returns the split knot of index VIndex
   //! to the split knots table for the v  parametric direction
   //! computed in this framework. The returned value is
   //! an index in the knots table relative to the v
   //! parametric direction of the BSpline surface analysed by this algorithm.
   //! Note: If UIndex is equal to 1, or to the number of split knots for the v
   //! parametric direction computed in
   //! this framework, the corresponding knot gives the
   //! parameter of one of the bounding curves of the surface.
   //! Exceptions
   //! Standard_RangeError if VIndex  is less than 1 or greater than the number
   //! of split knots for the v parametric direction computed in this framework.
   Standard_EXPORT Standard_Integer VSplitValue(const Standard_Integer VIndex) const;
 
 protected:
 private:
   Handle(TColStd_HArray1OfInteger) usplitIndexes;
   Handle(TColStd_HArray1OfInteger) vsplitIndexes;
 };
 
 #endif // _GeomConvert_BSplineSurfaceKnotSplitting_HeaderFile

This page was automatically generated by the 2.3.7 LXR engine. The LXR team