qpoint.cpp

奇趣公司比较新的qt/emd版本

    }
    return s;
}

#endif // QT_NO_DATASTREAM
/*!
    Returns the sum of the absolute values of x() and y(),
    traditionally known as the "Manhattan length" of the vector from
    the origin to the point. For example:

    \code
        QPoint oldPosition;

        MyWidget::mouseMoveEvent(QMouseEvent *event)
        {
            QPoint point = event->pos() - oldPosition;
            if (point.manhattanLength() > 3)
                // the mouse has moved more than 3 pixels since the oldPosition
        }
    \endcode

    This is a useful, and quick to calculate, approximation to the
    true length:

    \code
        int trueManhattanLength = sqrt(pow(x(), 2) + pow(y(), 2));
    \endcode

    The tradition of "Manhattan length" arises because such distances
    apply to travelers who can only travel on a rectangular grid, like
    the streets of Manhattan.
*/
int QPoint::manhattanLength() const
{
    return qAbs(x())+qAbs(y());
}

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QPoint &p) {
    dbg.nospace() << "QPoint(" << p.x() << ',' << p.y() << ')';
    return dbg.space();
}

QDebug operator<<(QDebug d, const QPointF &p)
{
    d << "QPointF(" << p.x() << ", " << p.y() << ")";
    return d;
}
#endif

/*!
    \class QPointF
    \ingroup multimedia

    \brief The QPointF class defines a point in the plane using
    floating point precision.

    A point is specified by a x coordinate and an y coordinate which
    can be accessed using the x() and y() functions. The coordinates
    of the point are specified using floating point numbers for
    accuracy. The isNull() function returns true if both x and y are
    set to 0.0. The coordinates can be set (or altered) using the setX()
    and setY() functions, or alternatively the rx() and ry() functions which
    return references to the coordinates (allowing direct
    manipulation).

    Given a point \e p, the following statements are all equivalent:

    \code
        QPointF p;

        p.setX(p.x() + 1.0);
        p += QPoint(1.0, 0.0);
        p.rx()++;
    \endcode

    A QPointF object can also be used as a vector: Addition and
    subtraction are defined as for vectors (each component is added
    separately). A QPointF object can also be divided or multiplied by
    an \c int or a \c qreal.

    In addition, the QPointF class provides a constructor converting a
    QPoint object into a QPointF object, and a corresponding toPoint()
    function which returns a QPoint copy of \e this point. Finally,
    QPointF objects can be streamed as well as compared.

    \sa QPoint, QPolygonF
*/

/*!
    \fn QPointF::QPointF()

    Constructs a null point, i.e. with coordinates (0.0, 0.0)

    \sa isNull()
*/

/*!
    \fn QPointF::QPointF(const QPoint &point)

    Constructs a copy of the given \a point.

    \sa toPoint()
*/

/*!
    \fn QPointF::QPointF(qreal x, qreal y)

    Constructs a point with the given coordinates (\a x, \a y).

    \sa setX(), setY()
*/

/*!
    \fn bool QPointF::isNull() const

    Returns true if both the x and y coordinates are set to 0.0,
    otherwise returns false.
*/

/*!
    \fn qreal QPointF::x() const

    Returns the x-coordinate of this point.

    \sa setX(), rx()
*/

/*!
    \fn qreal QPointF::y() const

    Returns the y-coordinate of this point.

    \sa setY(), ry()
*/

/*!
    \fn void QPointF::setX(qreal x)

    Sets the x coordinate of this point to the given \a x coordinate.

    \sa x() setY()
*/

/*!
    \fn void QPointF::setY(qreal y)

    Sets the y coordinate of this point to the given \a y coordinate.

    \sa  y(), setX()
*/

/*!
    \fn qreal& QPointF::rx()

    Returns a reference to the x coordinate of this point.

    Using a reference makes it possible to directly manipulate x. For example:

    \code
         QPoint p(1.1, 2.5);
         p.rx()--;   // p becomes (0.1, 2.5)
    \endcode

    \sa x(), setX()
*/

/*!
    \fn qreal& QPointF::ry()

    Returns a reference to the y coordinate of this point.

    Using a reference makes it possible to directly manipulate y. For example:

    \code
        QPoint p(1.1, 2.5);
        p.ry()++;   // p becomes (1.1, 3.5)
    \endcode

    \sa y() setY()
*/

/*!
    \fn QPointF& QPointF::operator+=(const QPointF &point)

    Adds the given \a point to this point and returns a reference to
    this point. For example:

    \code
        QPoint p( 3.1, 7.1);
        QPoint q(-1.0, 4.1);
        p += q;    // p becomes (2.1, 11.2)
    \endcode

    \sa operator-=()
*/

/*!
    \fn QPointF& QPointF::operator-=(const QPointF &point)

    Subtracts the given \a point from this point and returns a reference
    to this point. For example:

    \code
        QPoint p( 3.1, 7.1);
        QPoint q(-1.0, 4.1);
        p -= q;    // p becomes (4.1, 3.0)
    \endcode

    \sa operator+=()
*/

/*!
    \fn QPointF& QPointF::operator*=(qreal factor)

    Multiplies this point's coordinates by the given \a factor, and
    returns a reference to this point. For example:

    \code
         QPoint p(-1.1, 4.1);
         p *= 2.5;    // p becomes (-2.75,10.25)
    \endcode

    \sa operator/=()
*/

/*!
    \fn QPointF& QPointF::operator/=(qreal divisor)

    Divides both x and y by the given \a divisor, and returns a reference
    to this point. For example:

    \code
        QPoint p(-2.75, 10.25);
        p /= 2.5;           // p becomes (-1.1,4.1)
    \endcode

    \sa operator*=()
*/

/*!
    \fn const QPointF operator+(const QPointF &p1, const QPointF &p2)
    \relates QPointF

    Returns a QPointF object that is the sum of the given points, \a p1
    and \a p2; each component is added separately.

    \sa QPointF::operator+=()
*/

/*!
    \fn const QPointF operator-(const QPointF &p1, const QPointF &p2)
    \relates QPointF

    Returns a QPointF object that is formed by subtracting \a p2 from \a p1;
    each component is subtracted separately.

    \sa QPointF::operator-=()
*/

/*!
    \fn const QPointF operator*(const QPointF &point, qreal factor)
    \relates QPointF

    Returns a copy of the given \a point,  multiplied by the given \a factor.

    \sa QPointF::operator*=()
*/

/*!
    \fn const QPointF operator*(qreal factor, const QPointF &point)
    \relates QPointF

    \overload

    Returns a copy of the given \a point, multiplied by the given \a factor.
*/

/*!
    \fn const QPointF operator-(const QPointF &point)
    \relates QPointF
    \overload

    Returns a QPointF object that is formed by changing the sign of
    both components of the given \a point.

    Equivalent to \c {QPointF(0,0) - point}.
*/

/*!
    \fn const QPointF operator/(const QPointF &point, qreal divisor)
    \relates QPointF

    Returns the QPointF object formed by dividing both components of
    the given \a point by the given \a divisor.

    \sa QPointF::operator/=()
*/

/*!
    \fn QPoint QPointF::toPoint() const

    Rounds the coordinates of this point to the nearest integer, and
    returns a QPoint object with the rounded coordinates.

    \sa QPointF()
*/

/*!
    \fn bool operator==(const QPointF &p1, const QPointF &p2)
    \relates QPointF

    Returns true if \a p1 is equal to \a p2; otherwise returns false.
*/

/*!
    \fn bool operator!=(const QPointF &p1, const QPointF &p2);
    \relates QPointF

    Returns true if \a p1 is not equal to \a p2; otherwise returns false.
*/

#ifndef QT_NO_DATASTREAM
/*!
    \fn QDataStream &operator<<(QDataStream &stream, const QPointF &point)
    \relates QPointF

    Writes the given \a point to the given \a stream and returns a
    reference to the stream.

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator<<(QDataStream &s, const QPointF &p)
{
    s << double(p.x()) << double(p.y());
    return s;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QPointF &point)
    \relates QPointF

    Reads a point from the given \a stream into the given \a point
    and returns a reference to the stream.

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator>>(QDataStream &s, QPointF &p)
{
    double x, y;
    s >> x;
    s >> y;
    p.setX(qreal(x));
    p.setY(qreal(y));
    return s;
}
#endif // QT_NO_DATASTREAM