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 // Created on: 1991-10-03
 // Created by: Jean Claude 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 _Geom2dConvert_HeaderFile
 #define _Geom2dConvert_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 <TColGeom2d_Array1OfBSplineCurve.hxx>
 #include <TColStd_Array1OfReal.hxx>
 #include <TColGeom2d_HArray1OfBSplineCurve.hxx>
 #include <TColStd_HArray1OfInteger.hxx>
 class Geom2d_BSplineCurve;
 class Geom2d_Curve;
 
 
 
 //! This package provides an implementation of algorithms to do
 //! the conversion between equivalent geometric entities from
 //! package Geom2d.
 //! It gives the possibility :
 //! . to obtain the B-spline representation of bounded curves.
 //! . to split a B-spline curve into several B-spline curves
 //! with some constraints of continuity,
 //! . to convert a B-spline curve into several Bezier curves
 //! or surfaces.
 //! All the 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 Geom2dConvert 
 {
 public:
 
   DEFINE_STANDARD_ALLOC
 
   
   //! -- Convert a curve to BSpline  by Approximation
   //!
   //! 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 or ToK2 are out of the bounds
   //! [FirstUKnotIndex, LastUKnotIndex]
   //! Raised if FromK1 = ToK2
   Standard_EXPORT static Handle(Geom2d_BSplineCurve) SplitBSplineCurve (const Handle(Geom2d_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(Geom2d_BSplineCurve) SplitBSplineCurve (const Handle(Geom2d_BSplineCurve)& C,
                                                                         const Standard_Real FromU1,
                                                                         const Standard_Real ToU2,
                                                                         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  Offset  curve or a  trimmed
   //! Offset curve.
   //! The returned B-spline is not periodic except if C is a
   //! Circle or an 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.
   //! Standard_ConstructionError:
   //! -   if C is a complete circle or ellipse, and if
   //! Parameterisation is not equal to
   //! Convert_TgtThetaOver2 or to Convert_RationalC1, or
   //! -   if C is a trimmed circle or ellipse and 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 and
   //! 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(Geom2d_BSplineCurve) CurveToBSplineCurve (const Handle(Geom2d_Curve)& C,
                                                                           const Convert_ParameterisationType Parameterisation = Convert_TgtThetaOver2);
   
   //! 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 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColGeom2d_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 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
                                         Handle(TColGeom2d_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 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
                                         const TColStd_Array1OfReal& ArrayOfToler,
                                         Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
                                         Handle(TColGeom2d_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
   Standard_EXPORT static void C0BSplineToC1BSplineCurve (Handle(Geom2d_BSplineCurve)& BS,
                                                          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
   Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom2d_BSplineCurve)& BS,
                                                                 Handle(TColGeom2d_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
   Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom2d_BSplineCurve)& BS,
                                                                 Handle(TColGeom2d_HArray1OfBSplineCurve)& tabBS,
                                                                 const Standard_Real AngularTolerance,
                                                                 const Standard_Real Tolerance);
 
 };
 
 #endif // _Geom2dConvert_HeaderFile

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