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

File indexing completed on 2025-01-18 10:03:38

 // Created on: 1991-10-03
 // Created by: JeanClaude VAUTHIER 
 // 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_HeaderFile
 #define _GeomConvert_HeaderFile
 
 #include <Standard.hxx>
 #include <Standard_DefineAlloc.hxx>
 #include <Standard_Handle.hxx>
 
 #include <Standard_Integer.hxx>
 #include <Standard_Boolean.hxx>
 #include <Standard_Real.hxx>
 #include <Convert_ParameterisationType.hxx>
 #include <TColGeom_Array1OfBSplineCurve.hxx>
 #include <TColStd_Array1OfReal.hxx>
 #include <TColGeom_HArray1OfBSplineCurve.hxx>
 #include <TColStd_HArray1OfInteger.hxx>
 class Geom_BSplineCurve;
 class Geom_BSplineSurface;
 class Geom_Curve;
 class Geom_Surface;
 
 
 //! The GeomConvert package provides some global functions as follows
 //! -   converting classical Geom curves into BSpline curves,
 //! -   segmenting BSpline curves, particularly at knots
 //! values: this function may be used in conjunction with the
 //! GeomConvert_BSplineCurveKnotSplitting
 //! class to segment a BSpline curve into arcs which
 //! comply with required continuity levels,
 //! -   converting classical Geom surfaces into BSpline surfaces, and
 //! -   segmenting BSpline surfaces, particularly at
 //! knots values: this function may be used in conjunction with the
 //! GeomConvert_BSplineSurfaceKnotSplitting
 //! class to segment a BSpline surface into patches
 //! which comply with required continuity levels.
 //! All geometric entities used in this package are bounded.
 //!
 //! References :
 //! . Generating the Bezier Points of B-spline curves and surfaces
 //! (Wolfgang Bohm) CAGD volume 13 number 6 november 1981
 //! . On NURBS: A Survey  (Leslie Piegl) IEEE Computer Graphics and
 //! Application January 1991
 //! . Curve and surface construction using rational B-splines
 //! (Leslie Piegl and Wayne Tiller) CAD Volume 19 number 9 november
 //! 1987
 //! . A survey of curve and surface methods in CAGD (Wolfgang BOHM)
 //! CAGD 1 1984
 class GeomConvert 
 {
 public:
 
   DEFINE_STANDARD_ALLOC
 
   
   //! Convert a curve from Geom by an approximation method
   //!
   //! This method computes the arc of B-spline curve between the two
   //! knots FromK1 and ToK2.  If C is periodic the arc has the same
   //! orientation as C if SameOrientation = Standard_True.
   //! If C is not periodic  SameOrientation is not used for the
   //! computation and C is oriented from the knot fromK1 to the knot toK2.
   //! We just keep the local definition of C between the knots
   //! FromK1 and ToK2.  The returned B-spline curve has its first
   //! and last knots with a multiplicity equal to degree + 1, where
   //! degree is the polynomial degree of C.
   //! The indexes of the knots FromK1 and ToK2 doesn't include the
   //! repetition of multiple knots in their definition.
   //! Raised if FromK1 = ToK2
   //! Raised if FromK1 or ToK2 are out of the bounds
   //! [FirstUKnotIndex, LastUKnotIndex]
   Standard_EXPORT static Handle(Geom_BSplineCurve) SplitBSplineCurve (const Handle(Geom_BSplineCurve)& C,
                                                                       const Standard_Integer FromK1,
                                                                       const Standard_Integer ToK2,
                                                                       const Standard_Boolean SameOrientation = Standard_True);
   
 
   //! This function computes the segment of B-spline curve between the
   //! parametric values FromU1, ToU2.
   //! If C is periodic the arc has the same orientation as C if
   //! SameOrientation = True.
   //! If C is not periodic SameOrientation is not used for the
   //! computation and C is oriented fromU1 toU2.
   //! If U1 and U2 and two parametric values we consider that
   //! U1 = U2 if Abs (U1 - U2) <= ParametricTolerance and
   //! ParametricTolerance must  be greater or equal to Resolution
   //! from package gp.
   //!
   //! Raised if FromU1 or ToU2 are out of the parametric bounds of the
   //! curve (The tolerance criterion is ParametricTolerance).
   //! Raised if Abs (FromU1 - ToU2) <= ParametricTolerance
   //! Raised if ParametricTolerance < Resolution from gp.
   Standard_EXPORT static Handle(Geom_BSplineCurve) SplitBSplineCurve (const Handle(Geom_BSplineCurve)& C,
                                                                       const Standard_Real FromU1,
                                                                       const Standard_Real ToU2,
                                                                       const Standard_Real ParametricTolerance,
                                                                       const Standard_Boolean SameOrientation = Standard_True);
   
 
   //! Computes the B-spline surface patche between the knots values
   //! FromUK1, ToUK2, FromVK1, ToVK2.
   //! If S is periodic in one direction the patche has the same
   //! orientation as S in this direction if the flag is true in this
   //! direction (SameUOrientation, SameVOrientation).
   //! If S is not periodic SameUOrientation and SameVOrientation are not
   //! used for the computation and S is oriented FromUK1 ToUK2 and
   //! FromVK1 ToVK2.
   //! Raised if
   //! FromUK1 = ToUK2 or FromVK1 = ToVK2
   //! FromUK1 or ToUK2 are out of the bounds
   //! [FirstUKnotIndex, LastUKnotIndex]
   //! FromVK1 or ToVK2 are out of the bounds
   //! [FirstVKnotIndex, LastVKnotIndex]
   Standard_EXPORT static Handle(Geom_BSplineSurface) SplitBSplineSurface (const Handle(Geom_BSplineSurface)& S,
                                                                           const Standard_Integer FromUK1,
                                                                           const Standard_Integer ToUK2,
                                                                           const Standard_Integer FromVK1,
                                                                           const Standard_Integer ToVK2,
                                                                           const Standard_Boolean SameUOrientation = Standard_True,
                                                                           const Standard_Boolean SameVOrientation = Standard_True);
   
 
   //! This method splits a B-spline surface patche between the
   //! knots values FromK1, ToK2 in one direction.
   //! If USplit = True then the splitting direction is the U parametric
   //! direction else it is the V parametric direction.
   //! If S is periodic in the considered direction the patche has the
   //! same orientation as S in this direction if SameOrientation is True
   //! If S is not periodic in this direction SameOrientation is not used
   //! for the computation and S is oriented FromK1 ToK2.
   //! Raised if FromK1 = ToK2 or if
   //! FromK1 or ToK2 are out of the bounds
   //! [FirstUKnotIndex, LastUKnotIndex] in the
   //! considered parametric direction.
   Standard_EXPORT static Handle(Geom_BSplineSurface) SplitBSplineSurface (const Handle(Geom_BSplineSurface)& S,
                                                                           const Standard_Integer FromK1,
                                                                           const Standard_Integer ToK2,
                                                                           const Standard_Boolean USplit,
                                                                           const Standard_Boolean SameOrientation = Standard_True);
   
 
   //! This method computes the B-spline surface patche between the
   //! parametric values FromU1, ToU2, FromV1, ToV2.
   //! If S is periodic in one direction the patche has the same
   //! orientation as S in this direction if the flag is True in this
   //! direction (SameUOrientation, SameVOrientation).
   //! If S is not periodic SameUOrientation and SameVOrientation are not
   //! used for the computation and S is oriented FromU1 ToU2 and
   //! FromV1 ToV2.
   //! If U1 and U2 and two parametric values we consider that U1 = U2 if
   //! Abs (U1 - U2) <= ParametricTolerance and ParametricTolerance must
   //! be greater or equal to Resolution from package gp.
   //!
   //! Raised if FromU1 or ToU2 or FromV1 or ToU2 are out of the
   //! parametric bounds of the surface (the tolerance criterion is
   //! ParametricTolerance).
   //! Raised if Abs (FromU1 - ToU2) <= ParametricTolerance or
   //! Abs (FromV1 - ToV2) <= ParametricTolerance.
   //! Raised if ParametricTolerance < Resolution.
   Standard_EXPORT static Handle(Geom_BSplineSurface) SplitBSplineSurface (const Handle(Geom_BSplineSurface)& S,
                                                                           const Standard_Real FromU1,
                                                                           const Standard_Real ToU2,
                                                                           const Standard_Real FromV1,
                                                                           const Standard_Real ToV2,
                                                                           const Standard_Real ParametricTolerance,
                                                                           const Standard_Boolean SameUOrientation = Standard_True,
                                                                           const Standard_Boolean SameVOrientation = Standard_True);
   
 
   //! This method splits the B-spline surface S in one direction
   //! between the parametric values FromParam1, ToParam2.
   //! If USplit = True then the Splitting direction is the U parametric
   //! direction else it is the V parametric direction.
   //! If S is periodic in the considered direction the patche has
   //! the same orientation as S in this direction if SameOrientation
   //! is true.
   //! If S is not periodic in the considered direction SameOrientation
   //! is not used for the computation and S is oriented FromParam1
   //! ToParam2.
   //! If U1 and U2 and two parametric values we consider that U1 = U2
   //! if Abs (U1 - U2) <= ParametricTolerance and ParametricTolerance
   //! must be greater or equal to Resolution from package gp.
   //!
   //! Raises if FromParam1 or ToParam2 are out of the parametric bounds
   //! of the surface in the considered direction.
   //! Raises if Abs (FromParam1 - ToParam2) <= ParametricTolerance.
   Standard_EXPORT static Handle(Geom_BSplineSurface) SplitBSplineSurface (const Handle(Geom_BSplineSurface)& S,
                                                                           const Standard_Real FromParam1,
                                                                           const Standard_Real ToParam2,
                                                                           const Standard_Boolean USplit,
                                                                           const Standard_Real ParametricTolerance,
                                                                           const Standard_Boolean SameOrientation = Standard_True);
   
   //! This function converts a non infinite curve from
   //! Geom into a  B-spline curve.  C must be   an ellipse or  a
   //! circle  or a trimmed conic  or a trimmed  line or a Bezier
   //! curve or a trimmed  Bezier curve or a  BSpline curve or  a
   //! trimmed  BSpline curve or  an  OffsetCurve.  The returned  B-spline is
   //! not periodic except  if C is a Circle  or an  Ellipse.  If
   //! the  Parameterisation is  QuasiAngular than  the returned
   //! curve is NOT periodic  in case a  periodic Geom_Circle or
   //! Geom_Ellipse.  For TgtThetaOver2_1 and TgtThetaOver2_2 the
   //! method   raises  an exception  in    case  of a  periodic
   //! Geom_Circle or a Geom_Ellipse ParameterisationType applies
   //! only    if  the curve  is   a  Circle  or  an   ellipse :
   //! TgtThetaOver2,  -- TgtThetaOver2_1, -- TgtThetaOver2_2, --
   //! TgtThetaOver2_3, -- TgtThetaOver2_4,
   //!
   //! Purpose: this is the classical rational parameterisation
   //! 2
   //! 1 - t
   //! cos(theta) = ------
   //! 2
   //! 1 + t
   //!
   //! 2t
   //! sin(theta) = ------
   //! 2
   //! 1 + t
   //!
   //! t = tan (theta/2)
   //!
   //! with TgtThetaOver2  the routine will compute the number of spans
   //! using the rule num_spans = [ (ULast - UFirst) / 1.2 ] + 1
   //! with TgtThetaOver2_N, N  spans will be forced: an error will
   //! be raized if (ULast - UFirst) >= PI and N = 1,
   //! ULast - UFirst >= 2 PI and N = 2
   //!
   //! QuasiAngular,
   //! here t is a rational function that approximates
   //! theta ----> tan(theta/2).
   //! Nevetheless the composing with above function yields exact
   //! functions whose square sum up to 1
   //! RationalC1 ;
   //! t is replaced by a polynomial function of u so as to grant
   //! C1 contiuity across knots.
   //! Exceptions
   //! Standard_DomainError:
   //! -   if the curve C is infinite, or
   //! -   if C is a (complete) circle or ellipse, and Parameterisation is equal to
   //! Convert_TgtThetaOver2_1 or Convert_TgtThetaOver2_2.
   //! Standard_ConstructionError:
   //! -   if C is a (complete) circle or ellipse, and if Parameterisation is not equal to
   //! Convert_TgtThetaOver2, Convert_RationalC1,
   //! Convert_QuasiAngular (the curve is converted
   //! in these three cases) or to Convert_TgtThetaOver2_1 or
   //! Convert_TgtThetaOver2_2 (another exception is raised in these two cases).
   //! -   if C is a trimmed circle or ellipse, if Parameterisation is equal to
   //! Convert_TgtThetaOver2_1 and if U2 - U1 > 0.9999 * Pi, where U1 and U2 are
   //! respectively the first and the last parameters of the
   //! trimmed curve (this method of parameterization
   //! cannot be used to convert a half-circle or a half-ellipse, for example), or
   //! -   if C is a trimmed circle or ellipse, if
   //! Parameterisation is equal to Convert_TgtThetaOver2_2 and U2 - U1 >
   //! 1.9999 * Pi where U1 and U2 are
   //! respectively the first and the last parameters of the
   //! trimmed curve (this method of parameterization
   //! cannot be used to convert a quasi-complete circle or ellipse).
   Standard_EXPORT static Handle(Geom_BSplineCurve) CurveToBSplineCurve (const Handle(Geom_Curve)& C,
                                                                         const Convert_ParameterisationType Parameterisation = Convert_TgtThetaOver2);
   
 
   //! This algorithm converts a non infinite surface from Geom
   //! into a B-spline surface.
   //! S must be a trimmed plane or a trimmed cylinder or a trimmed cone
   //! or a trimmed sphere or a trimmed torus or a sphere or a torus or
   //! a Bezier surface of a trimmed Bezier surface or a trimmed swept
   //! surface with a corresponding basis curve which can be turned into
   //! a B-spline curve   (see the method CurveToBSplineCurve).
   //! Raises DomainError if the type of the surface is not previously defined.
   Standard_EXPORT static Handle(Geom_BSplineSurface) SurfaceToBSplineSurface (const Handle(Geom_Surface)& S);
   
   //! This Method concatenates G1 the ArrayOfCurves as far
   //! as it  is possible.
   //! ArrayOfCurves[0..N-1]
   //! ArrayOfToler contains the  biggest tolerance of the two
   //! points shared by two consecutives curves.
   //! Its dimension: [0..N-2]
   //! ClosedFlag     indicates if the ArrayOfCurves is closed.
   //! In this case ClosedTolerance contains the biggest tolerance
   //! of the two points which are at the closure.
   //! Otherwise its value is 0.0
   //! ClosedFlag becomes False on the output
   //! if it is impossible to build closed curve.
   Standard_EXPORT static void ConcatG1 (TColGeom_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColGeom_HArray1OfBSplineCurve)& ArrayOfConcatenated,
                                         Standard_Boolean& ClosedFlag,
                                         const Standard_Real ClosedTolerance);
   
   //! This Method concatenates C1 the ArrayOfCurves as far
   //! as it is possible.
   //! ArrayOfCurves[0..N-1]
   //! ArrayOfToler contains the  biggest tolerance of the two
   //! points shared by two consecutives curves.
   //! Its dimension: [0..N-2]
   //! ClosedFlag     indicates if the ArrayOfCurves is closed.
   //! In this case ClosedTolerance contains the biggest tolerance
   //! of the two points which are at the closure.
   //! Otherwise its value is 0.0
   //! ClosedFlag becomes False on the output
   //! if it is impossible to build closed curve.
   Standard_EXPORT static void ConcatC1 (TColGeom_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
                                         Handle(TColGeom_HArray1OfBSplineCurve)& ArrayOfConcatenated,
                                         Standard_Boolean& ClosedFlag,
                                         const Standard_Real ClosedTolerance);
   
   //! This Method concatenates C1 the ArrayOfCurves as far
   //! as it is possible.
   //! ArrayOfCurves[0..N-1]
   //! ArrayOfToler contains the  biggest tolerance of the two
   //! points shared by two consecutives curves.
   //! Its dimension: [0..N-2]
   //! ClosedFlag     indicates if the ArrayOfCurves is closed.
   //! In this case ClosedTolerance contains the biggest tolerance
   //! of the two points which are at the closure.
   //! Otherwise its value is 0.0
   //! ClosedFlag becomes False on the output
   //! if it is impossible to build closed curve.
   Standard_EXPORT static void ConcatC1 (TColGeom_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
                                         Handle(TColGeom_HArray1OfBSplineCurve)& ArrayOfConcatenated,
                                         Standard_Boolean& ClosedFlag,
                                         const Standard_Real ClosedTolerance,
                                         const Standard_Real AngularTolerance);
   
   //! This  Method reduces as far as   it is possible the
   //! multiplicities of  the  knots of  the BSpline BS.(keeping  the
   //! geometry).  It returns a new BSpline which  could still be C0.
   //! tolerance is a  geometrical tolerance.
   //! The  Angular toleranceis in radians  and measures  the angle of
   //! the tangents  on  the left and on  the right  to decide if  the
   //! curve is G1 or not at a given point
   Standard_EXPORT static void C0BSplineToC1BSplineCurve (Handle(Geom_BSplineCurve)& BS,
                                                          const Standard_Real tolerance,
                                                          const Standard_Real AngularTolerance = 1.0e-7);
   
   //! This Method   reduces as far  as  it is possible  the
   //! multiplicities  of  the knots  of the BSpline  BS.(keeping the geometry).
   //! It returns an array of BSpline C1. tolerance is a geometrical tolerance.
   Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom_BSplineCurve)& BS,
                                                                 Handle(TColGeom_HArray1OfBSplineCurve)& tabBS,
                                                                 const Standard_Real tolerance);
   
   //! This   Method reduces as far   as it is  possible the
   //! multiplicities of  the  knots of  the  BSpline BS.(keeping the
   //! geometry).  It returns an array of BSpline C1.  tolerance is a
   //! geometrical tolerance : it  allows for the maximum deformation
   //! The  Angular tolerance is in  radians and measures the angle of
   //! the tangents on the left and on the right to decide if the curve
   //! is C1 or not at a given point
   Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom_BSplineCurve)& BS,
                                                                 Handle(TColGeom_HArray1OfBSplineCurve)& tabBS,
                                                                 const Standard_Real AngularTolerance,
                                                                 const Standard_Real tolerance);
 
 };
 
 #endif // _GeomConvert_HeaderFile

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