qwt_interval.cpp

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/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * Qwt Widget Library
 * Copyright (C) 1997   Josef Wilgen
 * Copyright (C) 2002   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_interval.h"
#include "qwt_math.h"
#include <qalgorithms.h>

QwtInterval QwtInterval::normalized() const
{
    if ( d_minValue > d_maxValue )
    {
        return inverted();
    }
    if ( d_minValue == d_maxValue && d_borderFlags == ExcludeMinimum )
    {
        return inverted();
    }

    return *this;
}

QwtInterval QwtInterval::inverted() const
{
    BorderFlags borderFlags = IncludeBorders;
    if ( d_borderFlags & ExcludeMinimum )
        borderFlags |= ExcludeMaximum;
    if ( d_borderFlags & ExcludeMaximum )
        borderFlags |= ExcludeMinimum;

    return QwtInterval( d_maxValue, d_minValue, borderFlags );
}

bool QwtInterval::contains( double value ) const
{
    if ( !isValid() )
        return false;

    if ( value < d_minValue || value > d_maxValue )
        return false;

    if ( value == d_minValue && d_borderFlags & ExcludeMinimum )
        return false;

    if ( value == d_maxValue && d_borderFlags & ExcludeMaximum )
        return false;

    return true;
}

QwtInterval QwtInterval::unite( const QwtInterval &other ) const
{
    /*
     If one of the intervals is invalid return the other one.
     If both are invalid return an invalid default interval
     */
    if ( !isValid() )
    {
        if ( !other.isValid() )
            return QwtInterval();
        else
            return other;
    }
    if ( !other.isValid() )
        return *this;

    QwtInterval united;
    BorderFlags flags = IncludeBorders;

    // minimum
    if ( d_minValue < other.minValue() )
    {
        united.setMinValue( d_minValue );
        flags &= d_borderFlags & ExcludeMinimum;
    }
    else if ( other.minValue() < d_minValue )
    {
        united.setMinValue( other.minValue() );
        flags &= other.borderFlags() & ExcludeMinimum;
    }
    else // d_minValue == other.minValue()
    {
        united.setMinValue( d_minValue );
        flags &= ( d_borderFlags & other.borderFlags() ) & ExcludeMinimum;
    }

    // maximum
    if ( d_maxValue > other.maxValue() )
    {
        united.setMaxValue( d_maxValue );
        flags &= d_borderFlags & ExcludeMaximum;
    }
    else if ( other.maxValue() > d_maxValue )
    {
        united.setMaxValue( other.maxValue() );
        flags &= other.borderFlags() & ExcludeMaximum;
    }
    else // d_maxValue == other.maxValue() )
    {
        united.setMaxValue( d_maxValue );
        flags &= d_borderFlags & other.borderFlags() & ExcludeMaximum;
    }

    united.setBorderFlags( flags );
    return united;
}

QwtInterval QwtInterval::intersect( const QwtInterval &other ) const
{
    if ( !other.isValid() || !isValid() )
        return QwtInterval();

    QwtInterval i1 = *this;
    QwtInterval i2 = other;

    // swap i1/i2, so that the minimum of i1
    // is smaller then the minimum of i2

    if ( i1.minValue() > i2.minValue() )
    {
        qSwap( i1, i2 );
    }
    else if ( i1.minValue() == i2.minValue() )
    {
        if ( i1.borderFlags() & ExcludeMinimum )
            qSwap( i1, i2 );
    }

    if ( i1.maxValue() < i2.minValue() )
    {
        return QwtInterval();
    }

    if ( i1.maxValue() == i2.minValue() )
    {
        if ( i1.borderFlags() & ExcludeMaximum ||
            i2.borderFlags() & ExcludeMinimum )
        {
            return QwtInterval();
        }
    }

    QwtInterval intersected;
    BorderFlags flags = IncludeBorders;

    intersected.setMinValue( i2.minValue() );
    flags |= i2.borderFlags() & ExcludeMinimum;

    if ( i1.maxValue() < i2.maxValue() )
    {
        intersected.setMaxValue( i1.maxValue() );
        flags |= i1.borderFlags() & ExcludeMaximum;
    }
    else if ( i2.maxValue() < i1.maxValue() )
    {
        intersected.setMaxValue( i2.maxValue() );
        flags |= i2.borderFlags() & ExcludeMaximum;
    }
    else // i1.maxValue() == i2.maxValue()
    {
        intersected.setMaxValue( i1.maxValue() );
        flags |= i1.borderFlags() & i2.borderFlags() & ExcludeMaximum;
    }

    intersected.setBorderFlags( flags );
    return intersected;
}

QwtInterval& QwtInterval::operator|=( const QwtInterval &other )
{
    *this = *this | other;
    return *this;
}

QwtInterval& QwtInterval::operator&=( const QwtInterval &other )
{
    *this = *this & other;
    return *this;
}

bool QwtInterval::intersects( const QwtInterval &other ) const
{
    if ( !isValid() || !other.isValid() )
        return false;

    QwtInterval i1 = *this;
    QwtInterval i2 = other;

    // swap i1/i2, so that the minimum of i1
    // is smaller then the minimum of i2

    if ( i1.minValue() > i2.minValue() )
    {
        qSwap( i1, i2 );
    }
    else if ( i1.minValue() == i2.minValue() &&
              i1.borderFlags() & ExcludeMinimum )
    {
        qSwap( i1, i2 );
    }

    if ( i1.maxValue() > i2.minValue() )
    {
        return true;
    }
    if ( i1.maxValue() == i2.minValue() )
    {
        return !( ( i1.borderFlags() & ExcludeMaximum ) ||
            ( i2.borderFlags() & ExcludeMinimum ) );
    }
    return false;
}

QwtInterval QwtInterval::symmetrize( double value ) const
{
    if ( !isValid() )
        return *this;

    const double delta =
        qMax( qAbs( value - d_maxValue ), qAbs( value - d_minValue ) );

    return QwtInterval( value - delta, value + delta );
}

QwtInterval QwtInterval::limited( double lowerBound, double upperBound ) const
{
    if ( !isValid() || lowerBound > upperBound )
        return QwtInterval();

    double minValue = qMax( d_minValue, lowerBound );
    minValue = qMin( minValue, upperBound );

    double maxValue = qMax( d_maxValue, lowerBound );
    maxValue = qMin( maxValue, upperBound );

    return QwtInterval( minValue, maxValue, d_borderFlags );
}

QwtInterval QwtInterval::extend( double value ) const
{
    if ( !isValid() )
        return *this;

    return QwtInterval( qMin( value, d_minValue ),
        qMax( value, d_maxValue ), d_borderFlags );
}

QwtInterval& QwtInterval::operator|=( double value )
{
    *this = *this | value;
    return *this;
}

#ifndef QT_NO_DEBUG_STREAM

QDebug operator<<( QDebug debug, const QwtInterval &interval )
{
    const int flags = interval.borderFlags();

    debug.nospace() << "QwtInterval("
        << ( ( flags & QwtInterval::ExcludeMinimum ) ? "]" : "[" )
        << interval.minValue() << "," << interval.maxValue()
        << ( ( flags & QwtInterval::ExcludeMaximum ) ? "[" : "]" )
        << ")";

    return debug.space();
}

#endif