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    /* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
     * QwtPolar Widget Library
     * Copyright (C) 2008   Uwe Rathmann
     *
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the Qwt License, Version 1.0
     *****************************************************************************/
    
    #include "qwt_point_polar.h"
    #include "qwt_math.h"
    
    #if QT_VERSION < 0x040601
    #define qAtan2(y, x) ::atan2(y, x)
    #endif
    
    /*!
       Convert and assign values from a point in Cartesian coordinates
    
       \param p Point in Cartesian coordinates
       \sa setPoint(), toPoint()
    */
    QwtPointPolar::QwtPointPolar( const QPointF &p )
    {
        d_radius = qSqrt( qwtSqr( p.x() ) + qwtSqr( p.y() ) );
        d_azimuth = qAtan2( p.y(), p.x() );
    }
    
    /*!
       Convert and assign values from a point in Cartesian coordinates
       \param p Point in Cartesian coordinates
    */
    void QwtPointPolar::setPoint( const QPointF &p )
    {
        d_radius = qSqrt( qwtSqr( p.x() ) + qwtSqr( p.y() ) );
        d_azimuth = qAtan2( p.y(), p.x() );
    }
    
    /*!
       Convert and return values in Cartesian coordinates
    
       \return Converted point in Cartesian coordinates
    
       \note Invalid or null points will be returned as QPointF(0.0, 0.0)
       \sa isValid(), isNull()
    */
    QPointF QwtPointPolar::toPoint() const
    {
        if ( d_radius <= 0.0 )
            return QPointF( 0.0, 0.0 );
    
        const double x = d_radius * qCos( d_azimuth );
        const double y = d_radius * qSin( d_azimuth );
    
        return QPointF( x, y );
    }
    
    /*!
        \brief Compare 2 points
    
        Two points are equal to each other if radius and
        azimuth-coordinates are the same. Points are not equal, when
        the azimuth differs, but other.azimuth() == azimuth() % (2 * PI).
    
        \return True if the point is equal to other; otherwise return false.
    
        \sa normalized()
    */
    bool QwtPointPolar::operator==( const QwtPointPolar &other ) const
    {
        return d_radius == other.d_radius && d_azimuth == other.d_azimuth;
    }
    
    /*!
        Compare 2 points
    
        Two points are equal to each other if radius and
        azimuth-coordinates are the same. Points are not equal, when
        the azimuth differs, but other.azimuth() == azimuth() % (2 * PI).
    
        \return True if the point is not equal to other; otherwise return false.
        \sa normalized()
    */
    bool QwtPointPolar::operator!=( const QwtPointPolar &other ) const
    {
        return d_radius != other.d_radius || d_azimuth != other.d_azimuth;
    }
    
    /*!
       Normalize radius and azimuth
    
       When the radius is < 0.0 it is set to 0.0. The azimuth is
       a value >= 0.0 and < 2 * M_PI.
    
       \return Normalized point
    */
    QwtPointPolar QwtPointPolar::normalized() const
    {
        const double radius = qMax( d_radius, 0.0 );
    
        double azimuth = d_azimuth;
        if ( azimuth < -2.0 * M_PI || azimuth >= 2 * M_PI )
            azimuth = ::fmod( d_azimuth, 2 * M_PI );
    
        if ( azimuth < 0.0 )
            azimuth += 2 * M_PI;
    
        return QwtPointPolar( azimuth, radius );
    }
    
    #ifndef QT_NO_DEBUG_STREAM
    
    QDebug operator<<( QDebug debug, const QwtPointPolar &point )
    {
        debug.nospace() << "QwtPointPolar(" 
            << point.azimuth() << "," << point.radius() << ")";
    
        return debug.space();
    }
    
    #endif