QPolygon 類提供使用整數精度的點列錶。 更多...
| 頭： |
#include <QPolygon>
|
| CMake: |
find_package(Qt6 REQUIRED COMPONENTS Gui)
target_link_libraries(mytarget PRIVATE Qt6::Gui)
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| qmake: |
QT += gui
|
| 繼承： | QList |
注意： 此類的所有函數 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 ) |
(從 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 ) |
QPolygon 對象是 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.
QPolygon 類是 隱式共享 .
另請參閱 QList , QPolygonF ，和 QLine .
[constexpr noexcept]
QPolygon::
QPolygon
()
Constructs a polygon with no points.
另請參閱 QList::isEmpty ().
Constructs a polygon containing the specified points .
另請參閱 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()).
另請參閱 setPoints ().
Returns the bounding rectangle of the polygon, or QRect (0, 0, 0, 0) if the polygon is empty.
另請參閱 QList::isEmpty ().
返迴
true
若給定
point
is inside the polygon according to the specified
fillRule
；否則返迴
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.
另請參閱 intersects ().
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.
另請參閱 intersected ().
Extracts the coordinates of the point at the given index to * x 和 * y (if they are valid pointers).
另請參閱 setPoint ().
Returns the point at the given index .
這是重載函數。
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 ().
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);
這是重載函數。
Sets the point at the given index to the point specified by ( x , y ).
另請參閱 point (), putPoints ()，和 setPoints ().
Sets the point at the given index 到給定 point .
這是重載函數。
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 ().
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);
這是重載函數。
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 this polygon with other 。此操作很快且從不失敗。
[since 6.4]
QPolygonF
QPolygon::
toPolygonF
() const
Returns this polygon as a polygon with floating point accuracy.
該函數在 Qt 6.4 引入。
另請參閱 QPolygonF::toPolygon ().
Translates all points in the polygon by ( dx , dy ).
另請參閱 translated ().
Translates all points in the polygon by the given offset .
這是重載函數。
另請參閱 translated ().
Returns a copy of the polygon that is translated by ( dx , dy ).
另請參閱 translate ().
Returns a copy of the polygon that is translated by the given offset .
這是重載函數。
另請參閱 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.
另請參閱 intersected () 和 subtracted ().
Returns the polygon as a QVariant
寫入給定 polygon 到給定 stream ，並返迴流引用。
另請參閱 序列化 Qt 數據類型 .
Reads a polygon from the given stream 進給定 polygon ，並返迴流引用。
另請參閱 序列化 Qt 數據類型 .