QPolygon 類

The QPolygon class provides a vector of points using integer precision. 更多...

頭: #include <QPolygon>
qmake: QT += gui
繼承: QVector

注意: 此類的所有函數 可重入 .

公共函數

QPolygon ()
QPolygon (int size )
QPolygon (const QVector<QPoint> & points )
QPolygon (QVector<QPoint> && v )
QPolygon (const QRect & rectangle , bool closed = false)
QPolygon (const QPolygon & polygon )
QPolygon (QPolygon && other )
~QPolygon ()
QRect boundingRect () const
bool containsPoint (const QPoint & point , Qt::FillRule fillRule ) const
QPolygon intersected (const QPolygon & r ) const
bool intersects (const QPolygon & p ) const
void point (int index , int * x , int * y ) const
QPoint point (int index ) const
void putPoints (int index , int nPoints , int firstx , int firsty , ... )
void putPoints (int index , int nPoints , const QPolygon & fromPolygon , int fromIndex = 0)
void setPoint (int index , int x , int y )
void setPoint (int index , const QPoint & point )
void setPoints (int nPoints , const int * points )
void setPoints (int nPoints , int firstx , int firsty , ... )
QPolygon subtracted (const QPolygon & r ) const
void swap (QPolygon & other )
void translate (int dx , int dy )
void translate (const QPoint & offset )
QPolygon translated (int dx , int dy ) const
QPolygon translated (const QPoint & offset ) const
QPolygon united (const QPolygon & r ) const
QVariant operator QVariant () const
QPolygon & operator= (QPolygon && other )
QPolygon & operator= (const QPolygon & other )
QDataStream & operator<< (QDataStream & stream , const QPolygon & polygon )
QDataStream & operator>> (QDataStream & stream , QPolygon & polygon )

額外繼承成員

詳細描述

The QPolygon class provides a vector of points using integer precision.

A QPolygon object is a QVector < QPoint >. The easiest way to add points to a QPolygon is to use QVector 's streaming operator, as illustrated below:

        QPolygon polygon;
        polygon << QPoint(10, 20) << QPoint(20, 30);
					

In addition to the functions provided by QVector , QPolygon provides some point-specific functions.

Each point in a polygon can be retrieved by passing its index to the point () function. To populate the polygon, QPolygon 提供 setPoint () function to set the point at a given index, the setPoints () function to set all the points in the polygon (resizing it to the given number of points), and the putPoints () function which copies a number of given points into the polygon from a specified index (resizing the polygon if necessary).

QPolygon 提供 boundingRect () 和 translate () functions for geometry functions. Use the QMatrix::map () function for more general transformations of QPolygons.

The QPolygon class is 隱式共享 .

另請參閱 QVector , QPolygonF ,和 QLine .

成員函數文檔編製

QPolygon:: QPolygon ()

Constructs a polygon with no points.

另請參閱 QVector::isEmpty ().

QPolygon:: QPolygon ( int size )

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

另請參閱 QVector::isEmpty ().

QPolygon:: QPolygon (const QVector < QPoint > & points )

Constructs a polygon containing the specified points .

另請參閱 setPoints ().

QPolygon:: QPolygon ( QVector < QPoint > && v )

Default constructs an instance of QPolygon.

QPolygon:: QPolygon (const QRect & rectangle , bool closed = false)

Constructs a polygon from the given rectangle 。若 closed is false, the polygon just contains the four points of the rectangle ordered clockwise, otherwise the polygon's fifth point is set to rectangle .topLeft().

Note that the bottom-right corner of the rectangle is located at (rectangle.x() + rectangle.width(), rectangle.y() + rectangle.height()).

另請參閱 setPoints ().

QPolygon:: QPolygon (const QPolygon & polygon )

構造副本為給定 polygon .

另請參閱 setPoints ().

QPolygon:: QPolygon ( QPolygon && other )

移動拷貝構造函數。

QPolygon:: ~QPolygon ()

Destroys the polygon.

QRect QPolygon:: boundingRect () const

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

另請參閱 QVector::isEmpty ().

bool QPolygon:: containsPoint (const QPoint & point , Qt::FillRule fillRule ) const

返迴 true 若給定 point is inside the polygon according to the specified fillRule ;否則返迴 false .

該函數在 Qt 4.3 引入。

QPolygon QPolygon:: intersected (const QPolygon & 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.

該函數在 Qt 4.3 引入。

另請參閱 intersects ().

bool QPolygon:: intersects (const QPolygon & p ) const

返迴 true if the current polygon intersects at any point the given polygon p 。也返迴 true if the current polygon contains or is contained by any part of p .

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

該函數在 Qt 5.10 引入。

另請參閱 intersected ().

void QPolygon:: point ( int index , int * x , int * y ) const

Extracts the coordinates of the point at the given index to * x 和 * y (if they are valid pointers).

另請參閱 setPoint ().

QPoint QPolygon:: point ( int index ) const

這是重載函數。

Returns the point at the given index .

void QPolygon:: putPoints ( int index , int nPoints , int firstx , int firsty , ... )

拷貝 nPoints points from the variable argument list into this polygon from the given index .

The points are given as a sequence of integers, starting with firstx then firsty , and so on. The polygon is resized if index+nPoints exceeds its current size.

The example code creates a polygon with three points (4,5), (6,7) and (8,9), by expanding the polygon from 1 to 3 points:

        QPolygon polygon(1);
        polygon[0] = QPoint(4, 5);
        polygon.putPoints(1, 2, 6,7, 8,9);
					

The following code has the same result, but here the putPoints() function overwrites rather than extends:

        QPolygon polygon(3);
        polygon.putPoints(0, 3, 4,5, 0,0, 8,9);
        polygon.putPoints(1, 1, 6,7);
					

另請參閱 setPoints ().

void QPolygon:: putPoints ( int index , int nPoints , const QPolygon & fromPolygon , int fromIndex = 0)

這是重載函數。

拷貝 nPoints points from the given fromIndex ( 0 by default) in fromPolygon into this polygon, starting at the specified index 。例如:

        QPolygon polygon1;
        polygon1.putPoints(0, 3, 1,2, 0,0, 5,6);
        // polygon1 is now the three-point polygon(1,2, 0,0, 5,6);
        QPolygon polygon2;
        polygon2.putPoints(0, 3, 4,4, 5,5, 6,6);
        // polygon2 is now (4,4, 5,5, 6,6);
        polygon1.putPoints(2, 3, polygon2);
        // polygon1 is now the five-point polygon(1,2, 0,0, 4,4, 5,5, 6,6);
					

void QPolygon:: setPoint ( int index , int x , int y )

Sets the point at the given index to the point specified by ( x , y ).

另請參閱 point (), putPoints (),和 setPoints ().

void QPolygon:: setPoint ( int index , const QPoint & point )

這是重載函數。

Sets the point at the given index 到給定 point .

void QPolygon:: setPoints ( int nPoints , const int * points )

Resizes the polygon to nPoints and populates it with the given points .

The example code creates a polygon with two points (10, 20) and (30, 40):

        static const int points[] = { 10, 20, 30, 40 };
        QPolygon polygon;
        polygon.setPoints(2, points);
					

另請參閱 setPoint () 和 putPoints ().

void QPolygon:: setPoints ( int nPoints , int firstx , int firsty , ... )

這是重載函數。

Resizes the polygon to nPoints and populates it with the points specified by the variable argument list. The points are given as a sequence of integers, starting with firstx then firsty , and so on.

The example code creates a polygon with two points (10, 20) and (30, 40):

        QPolygon polygon;
        polygon.setPoints(2, 10, 20, 30, 40);
					

QPolygon QPolygon:: subtracted (const QPolygon & 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.

該函數在 Qt 4.3 引入。

void QPolygon:: swap ( QPolygon & other )

Swaps polygon other with this polygon. This operation is very fast and never fails.

該函數在 Qt 4.8 引入。

void QPolygon:: translate ( int dx , int dy )

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

另請參閱 translated ().

void QPolygon:: translate (const QPoint & offset )

這是重載函數。

Translates all points in the polygon by the given offset .

另請參閱 translated ().

QPolygon QPolygon:: translated ( int dx , int dy ) const

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

該函數在 Qt 4.6 引入。

另請參閱 translate ().

QPolygon QPolygon:: translated (const QPoint & offset ) const

這是重載函數。

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

該函數在 Qt 4.6 引入。

另請參閱 translate ().

QPolygon QPolygon:: united (const QPolygon & r ) const

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

Set operations on polygons, will treat the polygons as areas, and implicitly close the polygon.

該函數在 Qt 4.3 引入。

另請參閱 intersected () 和 subtracted ().

QVariant QPolygon:: operator QVariant () const

Returns the polygon as a QVariant

QPolygon &QPolygon:: operator= ( QPolygon && other )

移動賦值運算符。

QPolygon &QPolygon:: operator= (const QPolygon & other )

拷貝賦值運算符。

相關非成員

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

寫入給定 polygon 到給定 stream ,並返迴流引用。

該函數在 Qt 4.4 引入。

另請參閱 序列化 Qt 數據類型 .

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

Reads a polygon from the given stream 進給定 polygon ,並返迴流引用。

該函數在 Qt 4.4 引入。

另請參閱 序列化 Qt 數據類型 .