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33fc476d89
* require qwt >=6.2 (and fallback to internal 6.3 if system's qwt doesn't suffice) * debian doesn't have qwt for Qt6 and won't have it for trixie
84 lines
2.4 KiB
C++
84 lines
2.4 KiB
C++
/******************************************************************************
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* Qwt Widget Library
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* Copyright (C) 1997 Josef Wilgen
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* Copyright (C) 2002 Uwe Rathmann
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the Qwt License, Version 1.0
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*****************************************************************************/
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#ifndef QWT_SPLINE_LOCAL_H
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#define QWT_SPLINE_LOCAL_H
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#include "qwt_global.h"
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#include "qwt_spline.h"
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/*!
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\brief A spline with C1 continuity
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QwtSplineLocal offers several standard algorithms for interpolating
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a curve with polynomials having C1 continuity at the control points.
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All algorithms are local in a sense, that changing one control point
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only few polynomials.
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*/
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class QWT_EXPORT QwtSplineLocal : public QwtSplineC1
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{
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public:
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/*!
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\brief Spline interpolation type
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All type of spline interpolations are lightweight algorithms
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calculating the slopes at a point by looking 1 or 2 points back
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and ahead.
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*/
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enum Type
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{
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/*!
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A cardinal spline
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The cardinal spline interpolation is a very cheap calculation with
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a locality of 1.
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*/
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Cardinal,
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/*!
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Parabolic blending is a cheap calculation with a locality of 1. Sometimes
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it is also called Cubic Bessel interpolation.
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*/
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ParabolicBlending,
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/*!
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The algorithm of H.Akima is a calculation with a locality of 2.
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*/
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Akima,
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/*!
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Piecewise Cubic Hermite Interpolating Polynomial (PCHIP) is an algorithm
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that is popular because of being offered by MATLAB.
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It preserves the shape of the data and respects monotonicity. It has a
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locality of 1.
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*/
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PChip
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};
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QwtSplineLocal( Type type );
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virtual ~QwtSplineLocal();
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Type type() const;
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virtual uint locality() const QWT_OVERRIDE;
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virtual QPainterPath painterPath( const QPolygonF& ) const QWT_OVERRIDE;
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virtual QVector< QLineF > bezierControlLines( const QPolygonF& ) const QWT_OVERRIDE;
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// calculating the parametric equations
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virtual QVector< QwtSplinePolynomial > polynomials( const QPolygonF& ) const QWT_OVERRIDE;
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virtual QVector< double > slopes( const QPolygonF& ) const QWT_OVERRIDE;
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private:
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const Type m_type;
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};
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#endif
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