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License statement text corrected; compiler warnings caused by Bison 2.41 disabled for MSVC; a few other compiler warnings on 54-bit Windows eliminated by appropriate type cast Wrong license statements corrected in several files. Copyright and license statements added in XSD and GLSL files. Copyright year updated in some files. Obsolete documentation files removed from DrawResources.
282 lines
13 KiB
Plaintext
282 lines
13 KiB
Plaintext
-- 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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package Geom2dConvert
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--- Purpose :
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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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uses Standard, TColStd, TColGeom2d,gp, Geom2d, Convert,GeomAbs
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is
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class BSplineCurveKnotSplitting;
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--- Purpose :
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-- This algorithm searches the knot values corresponding to the
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-- splitting of a given B-spline curve into several arcs with
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-- the same continuity. The continuity order is given at the
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-- construction time. It is possible to compute the curve arcs
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-- corresponding to this splitting with the method of package
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-- SplitBSplineCurve.
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class BSplineCurveToBezierCurve;
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--- Purpose :
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-- This algorithm converts a B-spline curve from the package Geom
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-- into several Bezier curves.
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class CompCurveToBSplineCurve;
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--- Purpose :
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-- This algorithm converts and concat sevral curve in a
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-- B-spline curve.
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class ApproxCurve;
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---Purpose : -- Convert a curve to BSpline by Approximation
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--
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SplitBSplineCurve (C : BSplineCurve from Geom2d;
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FromK1, ToK2 : Integer;
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SameOrientation : Boolean = Standard_True)
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returns mutable BSplineCurve from Geom2d
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--- Purpose :
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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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raises OutOfRange from Standard,
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--- Purpose :
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-- Raised if FromK1 or ToK2 are out of the bounds
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-- [FirstUKnotIndex, LastUKnotIndex]
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DomainError from Standard;
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--- Purpose : Raised if FromK1 = ToK2
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SplitBSplineCurve (C : BSplineCurve from Geom2d;
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FromU1, ToU2 : Real;
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ParametricTolerance : Real;
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SameOrientation : Boolean = Standard_True)
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returns mutable BSplineCurve from Geom2d
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--- Purpose :
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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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raises DomainError from Standard;
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--- Purpose :
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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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CurveToBSplineCurve (C : Curve from Geom2d ;
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Parameterisation : ParameterisationType from Convert
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= Convert_TgtThetaOver2)
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returns mutable BSplineCurve from Geom2d
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--- Purpose : 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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raises DomainError;
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ConcatG1(ArrayOfCurves : in out Array1OfBSplineCurve from TColGeom2d;
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ArrayOfToler : in Array1OfReal from TColStd;
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ArrayOfConcatenated : out HArray1OfBSplineCurve from TColGeom2d;
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ClosedFlag : in Boolean from Standard ;
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ClosedTolerance : in Real from Standard);
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--- Purpose : 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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-- ClosedTolerance 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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ConcatC1(ArrayOfCurves : in out Array1OfBSplineCurve from TColGeom2d;
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ArrayOfToler : in Array1OfReal from TColStd;
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ArrayOfIndices : out HArray1OfInteger from TColStd;
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ArrayOfConcatenated : out HArray1OfBSplineCurve from TColGeom2d;
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ClosedFlag : in Boolean from Standard ;
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ClosedTolerance : in Real from Standard);
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--- Purpose : 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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-- ClosedTolerance 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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--
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ConcatC1(ArrayOfCurves : in out Array1OfBSplineCurve from TColGeom2d;
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ArrayOfToler : in Array1OfReal from TColStd;
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ArrayOfIndices : out HArray1OfInteger from TColStd;
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ArrayOfConcatenated : out HArray1OfBSplineCurve from TColGeom2d;
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ClosedFlag : in Boolean from Standard ;
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ClosedTolerance : in Real from Standard;
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AngularTolerance : in Real from Standard) ;
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--- Purpose : 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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-- ClosedTolerance 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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C0BSplineToC1BSplineCurve(BS : in out BSplineCurve from Geom2d;
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Tolerance : in Real from Standard);
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--- Purpose : 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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C0BSplineToArrayOfC1BSplineCurve(BS : in BSplineCurve from Geom2d;
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tabBS : out HArray1OfBSplineCurve from TColGeom2d;
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Tolerance :in Real from Standard);
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--- Purpose :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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C0BSplineToArrayOfC1BSplineCurve( BS : in BSplineCurve from Geom2d;
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tabBS : out HArray1OfBSplineCurve from TColGeom2d;
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AngularTolerance : in Real from Standard;
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Tolerance : in Real from Standard) ;
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--- Purpose :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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end Geom2dConvert;
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