qline.cpp

奇趣公司比较新的qt/emd版本

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#include "qline.h"
#include "qdebug.h"
#include "qdatastream.h"
#include <private/qnumeric_p.h>

#include <math.h>

/*!
    \class QLine
    \ingroup multimedia

    \brief The QLine class provides a two-dimensional vector using
    integer precision.

    A QLine describes a finite length line (or a line segment) on a
    two-dimensional surface. The start and end points of the line are
    specified using integer point accuracy for coordinates. Use the
    QLineF constructor to retrieve a floating point copy.

    \table
    \row
        \o \inlineimage qline-point.png
        \o \inlineimage qline-coordinates.png
    \endtable

    The positions of the line's start and end points can be retrieved
    using the p1(), x1(), y1(), p2(), x2(), and y2() functions. The
    dx() and dy() functions return the horizontal and vertical
    components of the line. Use isNull() to determine whether the
    QLine represents a valid line or a null line.

    Finally, the line can be translated a given offset using the
    translate() function.

    \sa QLineF, QPolygon, QRect
*/

/*!
    \fn QLine::QLine()

    Constructs a null line.
*/

/*!
    \fn QLine::QLine(const QPoint &p1, const QPoint &p2)

    Constructs a line object that represents the line between \a p1 and
    \a p2.
*/

/*!
    \fn QLine::QLine(int x1, int y1, int x2, int y2)

    Constructs a line object that represents the line between (\a x1, \a y1) and
    (\a x2, \a y2).
*/

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

    Returns true if the line is not set up with valid start and end point;
    otherwise returns false.
*/

/*!
    \fn QPoint QLine::p1() const

    Returns the line's start point.

    \sa x1(), y1(), p2()
*/

/*!
    \fn QPoint QLine::p2() const

    Returns the line's end point.

    \sa x2(), y2(), p1()
*/

/*!
    \fn int QLine::x1() const

    Returns the x-coordinate of the line's start point.

    \sa p1()
*/

/*!
    \fn int QLine::y1() const

    Returns the y-coordinate of the line's start point.

    \sa p1()
*/

/*!
    \fn int QLine::x2() const

    Returns the x-coordinate of the line's end point.

    \sa p2()
*/

/*!
    \fn int QLine::y2() const

    Returns the y-coordinate of the line's end point.

    \sa p2()
*/

/*!
    \fn int QLine::dx() const

    Returns the horizontal component of the line's vector.

    \sa dy()
*/

/*!
    \fn int QLine::dy() const

    Returns the vertical component of the line's vector.

    \sa dx()
*/

/*!
    \fn bool QLine::operator!=(const QLine &line) const

    Returns true if the given \a line is not the same as \e this line.

    A line is different from another line if any of their start or
    end points differ, or the internal order of the points is different.
*/

/*!
    \fn bool QLine::operator==(const QLine &line) const

    Returns true if the given \a line is the same as \e this line.

    A line is identical to another line if the start and end points
    are identical, and the internal order of the points is the same.
*/

/*!
    \fn void QLine::translate(const QPoint &offset)

    Translates this line by the given \a offset.
*/

/*!
    \fn void QLine::translate(int dx, int dy)
    \overload

    Translates this line the distance specified by \a dx and \a dy.
*/

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug d, const QLine &p)
{
    d << "QLine(" << p.p1() << "," << p.p2() << ")";
    return d;
}
#endif

#ifndef QT_NO_DATASTREAM
/*!
    \relates QLine

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

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator<<(QDataStream &stream, const QLine &line)
{
    stream << line.p1() << line.p2();
    return stream;
}

/*!
    \relates QLine

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

    \sa {Format of the QDataStream Operators}
*/

QDataStream &operator>>(QDataStream &stream, QLine &line)
{
    QPoint p1, p2;
    stream >> p1;
    stream >> p2;
    line = QLine(p1, p2);

    return stream;
}

#endif // QT_NO_DATASTREAM


#ifndef M_2PI
#define M_2PI 6.28318530717958647692528676655900576
#endif

/*!
    \class QLineF
    \ingroup multimedia

    \brief The QLineF class provides a two-dimensional vector using
    floating point precision.

    A QLineF describes a finite length line (or line segment) on a
    two-dimensional surface. QLineF defines the start and end points
    of the line using floating point accuracy for coordinates.  Use
    the toLine() function to retrieve an integer based copy of this
    line.

    \table
    \row
        \o \inlineimage qline-point.png
        \o \inlineimage qline-coordinates.png
    \endtable

    The positions of the line's start and end points can be retrieved
    using the p1(), x1(), y1(), p2(), x2(), and y2() functions. The
    dx() and dy() functions return the horizontal and vertical
    components of the line, respectively.

    The line's length can be retrieved using the length() function,
    and altered using the setLength() function.  Use the isNull()
    function to determine whether the QLineF represents a valid line
    or a null line.

    The intersect() function determines the IntersectType for this
    line and a given line, while the angle() function returns the
    angle between the lines. In addition, the unitVector() function
    returns a line that has the same starting point as this line, but
    with a length of only 1, while the normalVector() function returns
    a line that is perpendicular to this line with the same starting
    point and length.

    Finally, the line can be translated a given offset using the
    translate() function, and can be traversed using the pointAt()
    function.

    \sa QLine, QPolygonF, QRectF
*/

/*!
    \enum QLineF::IntersectType

    Describes the intersection between two lines.

    \table
    \row
    \o \inlineimage qlinef-unbounded.png
    \o \inlineimage qlinef-bounded.png
    \row
    \o QLineF::UnboundedIntersection
    \o QLineF::BoundedIntersection
    \endtable

    \value NoIntersection Indicates that the lines do not intersect;
    i.e. they are parallel.

    \value UnboundedIntersection The two lines intersect,
    but not within the range defined by their lengths. This will be
    the case if the lines are not parallel.

    \value BoundedIntersection The two lines intersect with each other
    within the start and end points of each line.

    \sa intersect()
*/

/*!
    \fn QLineF::QLineF()

    Constructs a null line.
*/

/*!
    \fn QLineF::QLineF(const QPointF &p1, const QPointF &p2)

    Constructs a line object that represents the line between \a p1 and
    \a p2.
*/

/*!
    \fn QLineF::QLineF(qreal x1, qreal y1, qreal x2, qreal y2)

    Constructs a line object that represents the line between (\a x1, \a y1) and
    (\a x2, \a y2).
*/

/*!
    \fn QLineF::QLineF(const QLine &line)

    Construct a QLineF object from the given integer-based \a line.

    \sa toLine()