QPolygon 类提供使用整数精度的点列表。 更多...
| 头： | #include <QPolygon> |
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Gui)
target_link_libraries(mytarget PRIVATE Qt6::Gui) |
| qmake: | QT += gui |
| 继承： | QList |
注意： 此类的所有函数 可重入 .
| QPolygon () | |
| QPolygon (const QList<QPoint> & points ) | |
| QPolygon (const QRect & rectangle , bool closed = false) | |
| 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 ) |
(从 6.4 起)
QPolygonF
|
toPolygonF () const |
| 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 |
| QDataStream & | operator<< (QDataStream & stream , const QPolygon & polygon ) |
| QDataStream & | operator>> (QDataStream & stream , QPolygon & polygon ) |
A QPolygon object is a QList < QPoint >. The easiest way to add points to a QPolygon is to use QList 's streaming operator, as illustrated below:
QPolygon polygon; polygon << QPoint(10, 20) << QPoint(20, 30);
In addition to the functions provided by QList , 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 provides the 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 provides the boundingRect () 和 translate () functions for geometry functions. Use the QTransform::map () function for more general transformations of QPolygons.
The QPolygon class is 隐式共享 .
另请参阅 QList , QPolygonF ，和 QLine .
[constexpr noexcept]
QPolygon::
QPolygon
()
Constructs a polygon with no points.
另请参阅 QList::isEmpty ().
Constructs a polygon containing the specified points .
另请参阅 setPoints ().
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()).
另请参阅 setPoints ().
Returns the bounding rectangle of the polygon, or QRect (0, 0, 0, 0) if the polygon is empty.
另请参阅 QList::isEmpty ().
返回
true
若给定
point
is inside the polygon according to the specified
fillRule
；否则返回
false
.
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.
另请参阅 intersects ().
返回
true
if the current polygon intersects at any point the given polygon
p
。也返回
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.
另请参阅 intersected ().
Extracts the coordinates of the point at the given index to * x 和 * y (if they are valid pointers).
另请参阅 setPoint ().
这是重载函数。
Returns the point at the given index .
拷贝 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);
另请参阅 setPoints ().
这是重载函数。
拷贝 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);
Sets the point at the given index to the point specified by ( x , y ).
另请参阅 point (), putPoints ()，和 setPoints ().
这是重载函数。
Sets the point at the given index 到给定 point .
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);
另请参阅 setPoint () 和 putPoints ().
这是重载函数。
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);
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.
[noexcept]
void
QPolygon::
swap
(
QPolygon
&
other
)
Swaps polygon other with this polygon. This operation is very fast and never fails.
[since 6.4]
QPolygonF
QPolygon::
toPolygonF
() const
Returns this polygon as a polygon with floating point accuracy.
该函数在 Qt 6.4 引入。
另请参阅 QPolygonF::toPolygon ().
Translates all points in the polygon by ( dx , dy ).
另请参阅 translated ().
这是重载函数。
Translates all points in the polygon by the given offset .
另请参阅 translated ().
Returns a copy of the polygon that is translated by ( dx , dy ).
另请参阅 translate ().
这是重载函数。
Returns a copy of the polygon that is translated by the given offset .
另请参阅 translate ().
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.
另请参阅 intersected () 和 subtracted ().
Returns the polygon as a QVariant
写入给定 polygon 到给定 stream ，并返回流引用。
另请参阅 序列化 Qt 数据类型 .
Reads a polygon from the given stream 进给定 polygon ，并返回流引用。
另请参阅 序列化 Qt 数据类型 .