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4a3610588f
Methods GeomConvert::ConcatG1, GeomConvert::ConcatC1, Geom2dConvert::ConcatG1, Geom2dConvert::ConcatC1 are corrected to prevent exceeding maximum degree of BSpline curve in case of closed contour.
289 lines
13 KiB
C++
289 lines
13 KiB
C++
// Created on: 1991-10-03
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// Created by: Jean Claude VAUTHIER
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// Copyright (c) 1991-1999 Matra Datavision
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// Copyright (c) 1999-2014 OPEN CASCADE SAS
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//
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// This file is part of Open CASCADE Technology software library.
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//
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// This library is free software; you can redistribute it and/or modify it under
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// the terms of the GNU Lesser General Public License version 2.1 as published
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// by the Free Software Foundation, with special exception defined in the file
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// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
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// distribution for complete text of the license and disclaimer of any warranty.
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//
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// Alternatively, this file may be used under the terms of Open CASCADE
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// commercial license or contractual agreement.
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#ifndef _Geom2dConvert_HeaderFile
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#define _Geom2dConvert_HeaderFile
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#include <Standard.hxx>
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#include <Standard_DefineAlloc.hxx>
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#include <Standard_Handle.hxx>
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#include <Standard_Integer.hxx>
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#include <Standard_Boolean.hxx>
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#include <Standard_Real.hxx>
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#include <Convert_ParameterisationType.hxx>
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#include <TColGeom2d_Array1OfBSplineCurve.hxx>
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#include <TColStd_Array1OfReal.hxx>
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#include <TColGeom2d_HArray1OfBSplineCurve.hxx>
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#include <TColStd_HArray1OfInteger.hxx>
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class Geom2d_BSplineCurve;
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class Geom2d_Curve;
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class Geom2dConvert_BSplineCurveKnotSplitting;
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class Geom2dConvert_BSplineCurveToBezierCurve;
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class Geom2dConvert_CompCurveToBSplineCurve;
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class Geom2dConvert_ApproxCurve;
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//! This package provides an implementation of algorithmes to do
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//! the conversion between equivalent geometric entities from
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//! package Geom2d.
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//! It gives the possibility :
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//! . to obtain the B-spline representation of bounded curves.
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//! . to split a B-spline curve into several B-spline curves
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//! with some constraints of continuity,
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//! . to convert a B-spline curve into several Bezier curves
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//! or surfaces.
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//! All the geometric entities used in this package are bounded.
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//! References :
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//! . Generating the Bezier Points of B-spline curves and surfaces
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//! (Wolfgang Bohm) CAGD volume 13 number 6 november 1981
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//! . On NURBS: A Survey (Leslie Piegl) IEEE Computer Graphics and
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//! Application January 1991
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//! . Curve and surface construction using rational B-splines
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//! (Leslie Piegl and Wayne Tiller) CAD Volume 19 number 9 november
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//! 1987
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//! . A survey of curve and surface methods in CAGD (Wolfgang BOHM)
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//! CAGD 1 1984
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class Geom2dConvert
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{
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public:
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DEFINE_STANDARD_ALLOC
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//! -- Convert a curve to BSpline by Approximation
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//!
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//! This method computes the arc of B-spline curve between the two
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//! knots FromK1 and ToK2. If C is periodic the arc has the same
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//! orientation as C if SameOrientation = Standard_True.
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//! If C is not periodic SameOrientation is not used for the
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//! computation and C is oriented from the knot fromK1 to the
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//! knot toK2.
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//! We just keep the local definition of C between the knots
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//! FromK1 and ToK2. The returned B-spline curve has its first
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//! and last knots with a multiplicity equal to degree + 1, where
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//! degree is the polynomial degree of C.
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//! The indexes of the knots FromK1 and ToK2 doesn't include the
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//! repetition of multiple knots in their definition.
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//!
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//! Raised if FromK1 or ToK2 are out of the bounds
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//! [FirstUKnotIndex, LastUKnotIndex]
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//! Raised if FromK1 = ToK2
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Standard_EXPORT static Handle(Geom2d_BSplineCurve) SplitBSplineCurve (const Handle(Geom2d_BSplineCurve)& C,
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const Standard_Integer FromK1,
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const Standard_Integer ToK2,
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const Standard_Boolean SameOrientation = Standard_True);
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//! This function computes the segment of B-spline curve between the
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//! parametric values FromU1, ToU2.
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//! If C is periodic the arc has the same orientation as C if
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//! SameOrientation = True.
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//! If C is not periodic SameOrientation is not used for the
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//! computation and C is oriented fromU1 toU2.
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//! If U1 and U2 and two parametric values we consider that
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//! U1 = U2 if Abs (U1 - U2) <= ParametricTolerance and
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//! ParametricTolerance must be greater or equal to Resolution
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//! from package gp.
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//!
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//! Raised if FromU1 or ToU2 are out of the parametric bounds of the
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//! curve (The tolerance criterion is ParametricTolerance).
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//! Raised if Abs (FromU1 - ToU2) <= ParametricTolerance
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//! Raised if ParametricTolerance < Resolution from gp.
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Standard_EXPORT static Handle(Geom2d_BSplineCurve) SplitBSplineCurve (const Handle(Geom2d_BSplineCurve)& C,
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const Standard_Real FromU1,
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const Standard_Real ToU2,
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const Standard_Real ParametricTolerance,
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const Standard_Boolean SameOrientation = Standard_True);
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//! This function converts a non infinite curve from
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//! Geom into a B-spline curve. C must be an ellipse or a
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//! circle or a trimmed conic or a trimmed line or a Bezier
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//! curve or a trimmed Bezier curve or a BSpline curve or a
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//! trimmed BSpline curve or an Offset curve or a trimmed
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//! Offset curve.
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//! The returned B-spline is not periodic except if C is a
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//! Circle or an Ellipse.
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//! ParameterisationType applies only if the curve is a Circle
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//! or an ellipse :
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//! TgtThetaOver2,
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//! TgtThetaOver2_1,
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//! TgtThetaOver2_2,
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//! TgtThetaOver2_3,
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//! TgtThetaOver2_4,
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//! Purpose: this is the classical rational parameterisation
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//! 2
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//! 1 - t
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//! cos(theta) = ------
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//! 2
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//! 1 + t
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//!
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//! 2t
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//! sin(theta) = ------
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//! 2
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//! 1 + t
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//!
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//! t = tan (theta/2)
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//!
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//! with TgtThetaOver2 the routine will compute the number of spans
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//! using the rule num_spans = [ (ULast - UFirst) / 1.2 ] + 1
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//! with TgtThetaOver2_N, N spans will be forced: an error will
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//! be raized if (ULast - UFirst) >= PI and N = 1,
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//! ULast - UFirst >= 2 PI and N = 2
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//!
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//! QuasiAngular,
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//! here t is a rational function that approximates
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//! theta ----> tan(theta/2).
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//! Neverthless the composing with above function yields exact
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//! functions whose square sum up to 1
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//! RationalC1 ;
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//! t is replaced by a polynomial function of u so as to grant
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//! C1 contiuity across knots.
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//! Exceptions
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//! Standard_DomainError if the curve C is infinite.
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//! Standard_ConstructionError:
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//! - if C is a complete circle or ellipse, and if
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//! Parameterisation is not equal to
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//! Convert_TgtThetaOver2 or to Convert_RationalC1, or
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//! - if C is a trimmed circle or ellipse and if
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//! Parameterisation is equal to
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//! Convert_TgtThetaOver2_1 and if U2 - U1 >
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//! 0.9999 * Pi where U1 and U2 are
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//! respectively the first and the last parameters of the
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//! trimmed curve (this method of parameterization
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//! cannot be used to convert a half-circle or a
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//! half-ellipse, for example), or
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//! - if C is a trimmed circle or ellipse and
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//! Parameterisation is equal to
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//! Convert_TgtThetaOver2_2 and U2 - U1 >
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//! 1.9999 * Pi where U1 and U2 are
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//! respectively the first and the last parameters of the
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//! trimmed curve (this method of parameterization
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//! cannot be used to convert a quasi-complete circle or ellipse).
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Standard_EXPORT static Handle(Geom2d_BSplineCurve) CurveToBSplineCurve (const Handle(Geom2d_Curve)& C,
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const Convert_ParameterisationType Parameterisation = Convert_TgtThetaOver2);
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//! This Method concatenates G1 the ArrayOfCurves as far
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//! as it is possible.
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//! ArrayOfCurves[0..N-1]
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//! ArrayOfToler contains the biggest tolerance of the two
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//! points shared by two consecutives curves.
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//! Its dimension: [0..N-2]
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//! ClosedFlag indicates if the ArrayOfCurves is closed.
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//! In this case ClosedTolerance contains the biggest tolerance
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//! of the two points which are at the closure.
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//! Otherwise its value is 0.0
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//! ClosedFlag becomes False on the output
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//! if it is impossible to build closed curve.
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Standard_EXPORT static void ConcatG1 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
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const TColStd_Array1OfReal& ArrayOfToler,
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Handle(TColGeom2d_HArray1OfBSplineCurve)& ArrayOfConcatenated,
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Standard_Boolean& ClosedFlag,
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const Standard_Real ClosedTolerance);
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//! This Method concatenates C1 the ArrayOfCurves as far
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//! as it is possible.
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//! ArrayOfCurves[0..N-1]
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//! ArrayOfToler contains the biggest tolerance of the two
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//! points shared by two consecutives curves.
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//! Its dimension: [0..N-2]
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//! ClosedFlag indicates if the ArrayOfCurves is closed.
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//! In this case ClosedTolerance contains the biggest tolerance
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//! of the two points which are at the closure.
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//! Otherwise its value is 0.0
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//! ClosedFlag becomes False on the output
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//! if it is impossible to build closed curve.
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Standard_EXPORT static void ConcatC1 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
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const TColStd_Array1OfReal& ArrayOfToler,
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Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
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Handle(TColGeom2d_HArray1OfBSplineCurve)& ArrayOfConcatenated,
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Standard_Boolean& ClosedFlag,
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const Standard_Real ClosedTolerance);
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//! This Method concatenates C1 the ArrayOfCurves as far
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//! as it is possible.
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//! ArrayOfCurves[0..N-1]
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//! ArrayOfToler contains the biggest tolerance of the two
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//! points shared by two consecutives curves.
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//! Its dimension: [0..N-2]
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//! ClosedFlag indicates if the ArrayOfCurves is closed.
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//! In this case ClosedTolerance contains the biggest tolerance
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//! of the two points which are at the closure.
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//! Otherwise its value is 0.0
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//! ClosedFlag becomes False on the output
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//! if it is impossible to build closed curve.
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Standard_EXPORT static void ConcatC1 (TColGeom2d_Array1OfBSplineCurve& ArrayOfCurves,
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const TColStd_Array1OfReal& ArrayOfToler,
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Handle(TColStd_HArray1OfInteger)& ArrayOfIndices,
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Handle(TColGeom2d_HArray1OfBSplineCurve)& ArrayOfConcatenated,
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Standard_Boolean& ClosedFlag,
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const Standard_Real ClosedTolerance,
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const Standard_Real AngularTolerance);
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//! This Method reduces as far as it is possible the
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//! multiplicities of the knots of the BSpline BS.(keeping the geometry).
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//! It returns a new BSpline which could still be C0.
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//! tolerance is a geometrical tolerance
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Standard_EXPORT static void C0BSplineToC1BSplineCurve (Handle(Geom2d_BSplineCurve)& BS,
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const Standard_Real Tolerance);
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//! This Method reduces as far as it is possible the
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//! multiplicities of the knots of the BSpline BS.(keeping the geometry).
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//! It returns an array of BSpline C1.
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//! Tolerance is a geometrical tolerance
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Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom2d_BSplineCurve)& BS,
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Handle(TColGeom2d_HArray1OfBSplineCurve)& tabBS,
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const Standard_Real Tolerance);
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//! This Method reduces as far as it is possible the
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//! multiplicities of the knots of the BSpline BS.(keeping the geometry).
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//! It returns an array of BSpline C1.
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//! tolerance is a geometrical tolerance
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Standard_EXPORT static void C0BSplineToArrayOfC1BSplineCurve (const Handle(Geom2d_BSplineCurve)& BS,
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Handle(TColGeom2d_HArray1OfBSplineCurve)& tabBS,
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const Standard_Real AngularTolerance,
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const Standard_Real Tolerance);
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protected:
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private:
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friend class Geom2dConvert_BSplineCurveKnotSplitting;
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friend class Geom2dConvert_BSplineCurveToBezierCurve;
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friend class Geom2dConvert_CompCurveToBSplineCurve;
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friend class Geom2dConvert_ApproxCurve;
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};
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#endif // _Geom2dConvert_HeaderFile
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