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QPolygonF Class Reference
[Модуль QtGui]

The QPolygonF class provides a vector of points using floating point precision. Далее...

 #include <QPolygonF>

Inherits QVector<QPointF>.

Замечание: Все функции в этом классе реентерабельны.

• Список всех членов, включая унаследованные

Открытые функции

• 64 public functions inherited from QVector

Связанные нечлены класса

Дополнительные унаследованные члены

• 2 статических открытых члена, унаследованных от QVector

Подробное описание

The QPolygonF class provides a vector of points using floating point precision.

A QPolygonF is a QVector<QPointF>. The easiest way to add points to a QPolygonF is to use its streaming operator, as illustrated below:

         QPolygonF polygon;
         polygon << QPointF(10.4, 20.5) << QPointF(20.2, 30.2);

In addition to the functions provided by QVector, QPolygonF provides the boundingRect() and translate() functions for geometry operations. Use the QMatrix::map() function for more general transformations of QPolygonFs.

QPolygonF also provides the isClosed() function to determine whether a polygon's start and end points are the same, and the toPolygon() function returning an integer precision copy of this polygon.

The QPolygonF class is implicitly shared.

See also QVector, QPolygon, and QLineF.

Описание функций-членов

QPolygonF::QPolygonF ()

Constructs a polygon with no points.

See also QVector::isEmpty().

QPolygonF::QPolygonF ( int size )

Constructs a polygon of the given size. Creates an empty polygon if size == 0.

See also QVector::isEmpty().

QPolygonF::QPolygonF ( const QPolygonF & polygon )

Constructs a copy of the given polygon.

QPolygonF::QPolygonF ( const QVector<QPointF> & points )

Constructs a polygon containing the specified points.

QPolygonF::QPolygonF ( const QRectF & rectangle )

Constructs a closed polygon from the specified rectangle.

The polygon contains the four vertices of the rectangle in clockwise order starting and ending with the top-left vertex.

See also isClosed().

QPolygonF::QPolygonF ( const QPolygon & polygon )

Constructs a float based polygon from the specified integer based polygon.

See also toPolygon().

QPolygonF::~QPolygonF ()

Destroys the polygon.

QRectF QPolygonF::boundingRect () const

Returns the bounding rectangle of the polygon, or QRectF(0,0,0,0) if the polygon is empty.

See also QVector::isEmpty().

bool QPolygonF::containsPoint ( const QPointF & point, Qt::FillRule fillRule ) const

Returns true if the given point is inside the polygon according to the specified fillRule; otherwise returns false.

Эта функция была введена в Qt 4.3.

QPolygonF QPolygonF::intersected ( const QPolygonF & r ) const

Returns a polygon which is the intersection of this polygon and r.

Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.

Эта функция была введена в Qt 4.3.

bool QPolygonF::isClosed () const

Returns true if the polygon is closed; otherwise returns false.

A polygon is said to be closed if its start point and end point are equal.

See also QVector::first() and QVector::last().

QPolygonF QPolygonF::subtracted ( const QPolygonF & r ) const

Returns a polygon which is r subtracted from this polygon.

Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.

Эта функция была введена в Qt 4.3.

QPolygon QPolygonF::toPolygon () const

Creates and returns a QPolygon by converting each QPointF to a QPoint.

See also QPointF::toPoint().

void QPolygonF::translate ( const QPointF & offset )

Translate all points in the polygon by the given offset.

See also translated().

void QPolygonF::translate ( qreal dx, qreal dy )

Это перегруженная функция.

Translates all points in the polygon by (dx, dy).

See also translated().

QPolygonF QPolygonF::translated ( const QPointF & offset ) const

Returns a copy of the polygon that is translated by the given offset.

Эта функция была введена в Qt 4.6.

Смотрите также translate().

QPolygonF QPolygonF::translated ( qreal dx, qreal dy ) const

Это перегруженная функция.

Returns a copy of the polygon that is translated by (dx, dy).

Эта функция была введена в Qt 4.6.

Смотрите также translate().

QPolygonF QPolygonF::united ( const QPolygonF & r ) const

Returns a polygon which is the union of this polygon and r.

Set operations on polygons will treat the polygons as areas. Non-closed polygons will be treated as implicitly closed.

Эта функция была введена в Qt 4.3.

See also intersected() and subtracted().

Связанные нечлены класса

QDataStream & operator<< ( QDataStream & stream, const QPolygonF & polygon )

Writes the given polygon to the given stream, and returns a reference to the stream.

Смотрите также Формат операторов QDataStream.

QDataStream & operator>> ( QDataStream & stream, QPolygonF & polygon )

Reads a polygon from the given stream into the given polygon, and returns a reference to the stream.

Смотрите также Формат операторов QDataStream.