The QPolygon class provides a list of points using integer precision. \inmodule QtGui. More...

#include <qpolygon.h>

Inheritance diagram for QPolygon:

Collaboration diagram for QPolygon:

Public Member Functions
	QPolygon ()=default

Q_IMPLICIT	QPolygon (const QList< QPoint > &v)

Q_IMPLICIT	QPolygon (QList< QPoint > &&v) noexcept

Q_IMPLICIT Q_GUI_EXPORT	QPolygon (const QRect &r, bool closed=false)

Q_GUI_EXPORT	QPolygon (int nPoints, const int *points)

void	swap (QPolygon &other) noexcept

Q_GUI_EXPORT	operator QVariant () const

Q_GUI_EXPORT void	translate (int dx, int dy)

void	translate (const QPoint &offset)

Q_GUI_EXPORT QPolygon	translated (int dx, int dy) const

QPolygon	translated (const QPoint &offset) const

Q_GUI_EXPORT QRect	boundingRect () const

Q_GUI_EXPORT void	point (int i, int x, int y) const

QPoint	point (int i) const

Q_GUI_EXPORT void	setPoint (int index, int x, int y)

void	setPoint (int index, const QPoint &p)

Q_GUI_EXPORT void	setPoints (int nPoints, const int *points)

Q_GUI_EXPORT void	setPoints (int nPoints, int firstx, int firsty,...)

Q_GUI_EXPORT void	putPoints (int index, int nPoints, const int *points)

Q_GUI_EXPORT void	putPoints (int index, int nPoints, int firstx, int firsty,...)

Q_GUI_EXPORT void	putPoints (int index, int nPoints, const QPolygon &from, int fromIndex=0)

Q_GUI_EXPORT bool	containsPoint (const QPoint &pt, Qt::FillRule fillRule) const

Q_GUI_EXPORT QPolygon	united (const QPolygon &r) const

Q_GUI_EXPORT QPolygon	intersected (const QPolygon &r) const

Q_GUI_EXPORT QPolygon	subtracted (const QPolygon &r) const

Q_GUI_EXPORT bool	intersects (const QPolygon &r) const

Public Member Functions inherited from QList< QPoint >
	QList (DataPointer dd) noexcept

	QList ()=default

	QList (qsizetype size)

	QList (qsizetype size, parameter_type t)

	QList (std::initializer_list< QPoint > args)

	QList (InputIterator i1, InputIterator i2)

	QList (const String &str)

QList< QPoint > &	operator= (std::initializer_list< QPoint > args)

void	swap (QList &other) noexcept

QTypeTraits::compare_eq_result_container< QList, U >	operator== (const QList &other) const

QTypeTraits::compare_eq_result_container< QList, U >	operator!= (const QList &other) const

QTypeTraits::compare_lt_result_container< QList, U >	operator< (const QList &other) const noexcept(noexcept(std::lexicographical_compare< typename QList< U >::const_iterator, typename QList::const_iterator >(std::declval< QList< U >>().begin(), std::declval< QList< U >>().end(), other.begin(), other.end())))

QTypeTraits::compare_lt_result_container< QList, U >	operator> (const QList &other) const noexcept(noexcept(other< std::declval< QList< U >>()))

QTypeTraits::compare_lt_result_container< QList, U >	operator<= (const QList &other) const noexcept(noexcept(other< std::declval< QList< U >>()))

QTypeTraits::compare_lt_result_container< QList, U >	operator>= (const QList &other) const noexcept(noexcept(std::declval< QList< U >>()< other))

qsizetype	size () const noexcept

qsizetype	count () const noexcept

qsizetype	count (const AT &t) const noexcept

qsizetype	length () const noexcept

bool	isEmpty () const noexcept

void	resize (qsizetype size)

void	resize (qsizetype size, parameter_type c)

qsizetype	capacity () const

void	reserve (qsizetype size)

void	squeeze ()

void	detach ()

bool	isDetached () const noexcept

bool	isSharedWith (const QList< QPoint > &other) const

pointer	data ()

const_pointer	data () const noexcept

const_pointer	constData () const noexcept

void	clear ()

const_reference	at (qsizetype i) const noexcept

reference	operator[] (qsizetype i)

const_reference	operator[] (qsizetype i) const noexcept

void	append (parameter_type t)

void	append (const_iterator i1, const_iterator i2)

void	append (rvalue_ref t)

void	append (const QList< QPoint > &l)

void	append (QList< QPoint > &&l)

void	prepend (rvalue_ref t)

void	prepend (parameter_type t)

reference	emplaceBack (Args &&... args)

reference	emplaceFront (Args &&... args)

iterator	insert (qsizetype i, parameter_type t)

iterator	insert (qsizetype i, qsizetype n, parameter_type t)

iterator	insert (const_iterator before, parameter_type t)

iterator	insert (const_iterator before, qsizetype n, parameter_type t)

iterator	insert (const_iterator before, rvalue_ref t)

iterator	insert (qsizetype i, rvalue_ref t)

iterator	emplace (const_iterator before, Args &&... args)

iterator	emplace (qsizetype i, Args &&... args)

void	replace (qsizetype i, parameter_type t)

void	replace (qsizetype i, rvalue_ref t)

void	remove (qsizetype i, qsizetype n=1)

void	removeFirst () noexcept

void	removeLast () noexcept

value_type	takeFirst ()

value_type	takeLast ()

QList< QPoint > &	fill (parameter_type t, qsizetype size=-1)

void	removeAt (qsizetype i)

qsizetype	removeAll (const AT &t)

bool	removeOne (const AT &t)

qsizetype	removeIf (Predicate pred)

QPoint	takeAt (qsizetype i)

void	move (qsizetype from, qsizetype to)

iterator	begin ()

const_iterator	begin () const noexcept

iterator	end ()

const_iterator	end () const noexcept

const_iterator	cbegin () const noexcept

const_iterator	cend () const noexcept

const_iterator	constBegin () const noexcept

const_iterator	constEnd () const noexcept

reverse_iterator	rbegin ()

const_reverse_iterator	rbegin () const noexcept

reverse_iterator	rend ()

const_reverse_iterator	rend () const noexcept

const_reverse_iterator	crbegin () const noexcept

const_reverse_iterator	crend () const noexcept

iterator	erase (const_iterator begin, const_iterator end)

iterator	erase (const_iterator pos)

QPoint &	first ()

const QPoint &	first () const noexcept

QList< QPoint >	first (qsizetype n) const

const QPoint &	constFirst () const noexcept

QPoint &	last ()

const QPoint &	last () const noexcept

QList< QPoint >	last (qsizetype n) const

const QPoint &	constLast () const noexcept

bool	startsWith (parameter_type t) const

bool	endsWith (parameter_type t) const

QList< QPoint >	mid (qsizetype pos, qsizetype len=-1) const

QList< QPoint >	sliced (qsizetype pos) const

QList< QPoint >	sliced (qsizetype pos, qsizetype n) const

QPoint	value (qsizetype i) const

QPoint	value (qsizetype i, parameter_type defaultValue) const

void	swapItemsAt (qsizetype i, qsizetype j)

void	push_back (parameter_type t)

void	push_back (rvalue_ref t)

void	push_front (rvalue_ref t)

void	push_front (parameter_type t)

void	pop_back () noexcept

void	pop_front () noexcept

reference	emplace_back (Args &&... args)

bool	empty () const noexcept

reference	front ()

const_reference	front () const noexcept

reference	back ()

const_reference	back () const noexcept

void	shrink_to_fit ()

QList< QPoint > &	operator+= (const QList< QPoint > &l)

QList< QPoint > &	operator+= (QList< QPoint > &&l)

QList< QPoint > &	operator+= (parameter_type t)

QList< QPoint > &	operator+= (rvalue_ref t)

QList< QPoint >	operator+ (const QList< QPoint > &l) const

QList< QPoint >	operator+ (QList< QPoint > &&l) const

QList< QPoint > &	operator<< (parameter_type t)

QList< QPoint > &	operator<< (const QList< QPoint > &l)

QList< QPoint > &	operator<< (QList< QPoint > &&l)

QList< QPoint > &	operator<< (rvalue_ref t)

QList< QPoint >	toList () const noexcept

QList< QPoint >	toVector () const noexcept

Public Member Functions inherited from QListSpecialMethodsBase< T >
template<typename AT = T>
qsizetype	indexOf (const AT &t, qsizetype from=0) const noexcept

template<typename AT = T>
qsizetype	lastIndexOf (const AT &t, qsizetype from=-1) const noexcept

template<typename AT = T>
bool	contains (const AT &t) const noexcept

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QPolygon &polygon)

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

Additional Inherited Members
Public Types inherited from QList< QPoint >
using	Type = QPoint

using	value_type = QPoint

using	pointer = QPoint *

using	const_pointer = const QPoint *

using	reference = QPoint &

using	const_reference = const QPoint &

using	size_type = qsizetype

using	difference_type = qptrdiff

using	parameter_type = typename DataPointer::parameter_type

using	rvalue_ref = typename std::conditional< DataPointer::pass_parameter_by_value, DisableRValueRefs, QPoint && >::type

using	Iterator = iterator

using	ConstIterator = const_iterator

using	reverse_iterator = std::reverse_iterator< iterator >

using	const_reverse_iterator = std::reverse_iterator< const_iterator >

Static Public Member Functions inherited from QList< QPoint >
static QList< QPoint >	fromList (const QList< QPoint > &list) noexcept

static QList< QPoint >	fromVector (const QList< QPoint > &vector) noexcept

static QList< QPoint >	fromReadOnlyData (const QPoint(&t)[N]) noexcept

Protected Types inherited from QListSpecialMethodsBase< T >
using	Self = QList< T >

Protected Member Functions inherited from QListSpecialMethods< QPoint >
	~QListSpecialMethods ()=default

Protected Member Functions inherited from QListSpecialMethodsBase< T >
	~QListSpecialMethodsBase ()=default

Self *	self ()

const Self *	self () const

Detailed Description

The QPolygon class provides a list of points using integer precision. \inmodule QtGui.

\reentrant

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:

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() and translate() functions for geometry functions. Use the QTransform::map() function for more general transformations of QPolygons.

The QPolygon class is \l {Implicit Data Sharing}{implicitly shared}.

See also: QList, QPolygonF, QLine

Definition at line 56 of file qpolygon.h.

Constructor & Destructor Documentation

◆ QPolygon() [1/5]

QPolygon::QPolygon ( )

default

Constructs a polygon with no points.

See also: QList::isEmpty()

◆ QPolygon() [2/5]

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

inline

Constructs a polygon containing the specified points.

See also: setPoints()

Definition at line 61 of file qpolygon.h.

◆ QPolygon() [3/5]

Q_IMPLICIT QPolygon::QPolygon ( QList< QPoint > && v )

inlinenoexcept

Definition at line 62 of file qpolygon.h.

◆ QPolygon() [4/5]

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

Constructs a polygon from the given rectangle. If 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()).

See also: setPoints()

Definition at line 159 of file qpolygon.cpp.

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◆ QPolygon() [5/5]

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

Definition at line 178 of file qpolygon.cpp.

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Member Function Documentation

◆ boundingRect()

QRect QPolygon::boundingRect ( ) const

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

See also: QList::isEmpty()

Definition at line 422 of file qpolygon.cpp.

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◆ containsPoint()

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

Since: 4.3

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

Definition at line 818 of file qpolygon.cpp.

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◆ intersected()

QPolygon QPolygon::intersected ( const QPolygon & r ) const

Since: 4.3

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.

See also: intersects()

Definition at line 872 of file qpolygon.cpp.

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◆ intersects()

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

Since: 5.10

Returns true if the current polygon intersects at any point the given polygon p. Also returns 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.

See also: intersected()

Definition at line 910 of file qpolygon.cpp.

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◆ operator QVariant()

QPolygon::operator QVariant ( ) const

Returns the polygon as a QVariant

Definition at line 673 of file qpolygon.cpp.

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◆ point() [1/2]

QPoint QPolygon::point ( int index ) const

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Returns the point at the given index.

Definition at line 116 of file qpolygon.h.

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◆ point() [2/2]

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

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

See also: setPoint()

Definition at line 242 of file qpolygon.cpp.

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◆ putPoints() [1/3]

void QPolygon::putPoints	(	int	index,
		int	nPoints,
		const int *	points
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 339 of file qpolygon.cpp.

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◆ putPoints() [2/3]

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

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Copies nPoints points from the given fromIndex ( 0 by default) in fromPolygon into this polygon, starting at the specified index. For example:

Definition at line 401 of file qpolygon.cpp.

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◆ putPoints() [3/3]

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

Copies 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:

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

See also: setPoints()

Definition at line 371 of file qpolygon.cpp.

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◆ setPoint() [1/2]

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

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Sets the point at the given index to the given point.

Definition at line 113 of file qpolygon.h.

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◆ setPoint() [2/2]

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

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

See also: point(), putPoints(), setPoints(),

Definition at line 271 of file qpolygon.cpp.

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◆ setPoints() [1/2]

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):

See also: setPoint(), putPoints()

Definition at line 289 of file qpolygon.cpp.

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◆ setPoints() [2/2]

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

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

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):

Definition at line 313 of file qpolygon.cpp.

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◆ subtracted()

QPolygon QPolygon::subtracted ( const QPolygon & r ) const

Since: 4.3

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.

Definition at line 890 of file qpolygon.cpp.

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◆ swap()

void QPolygon::swap ( QPolygon & other )

inlinenoexcept

Since: 4.8

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

Definition at line 65 of file qpolygon.h.

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◆ translate() [1/2]

void QPolygon::translate ( const QPoint & offset )

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Translates all points in the polygon by the given offset.

See also: translated()

Definition at line 119 of file qpolygon.h.

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◆ translate() [2/2]

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

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

See also: translated()

Definition at line 189 of file qpolygon.cpp.

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◆ translated() [1/2]

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

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Since: 4.6

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

See also: translate()

Definition at line 122 of file qpolygon.h.

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◆ translated() [2/2]

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

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

Since: 4.6

See also: translate()

Definition at line 218 of file qpolygon.cpp.

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◆ united()

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

Since: 4.3

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.

See also: intersected(), subtracted()

Definition at line 853 of file qpolygon.cpp.

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Friends And Related Function Documentation

◆ operator<<()

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

Since: 4.4

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

See also: {Serializing Qt Data Types}

Definition at line 692 of file qpolygon.cpp.

◆ operator>>()

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

Since: 4.4

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

See also: {Serializing Qt Data Types}

Definition at line 708 of file qpolygon.cpp.

The documentation for this class was generated from the following files:

src/gui/painting/qpolygon.h
src/gui/painting/qpolygon.cpp

Public Member Functions

Related Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QPolygon() [1/5]

◆ QPolygon() [2/5]

◆ QPolygon() [3/5]

◆ QPolygon() [4/5]

◆ QPolygon() [5/5]

Member Function Documentation

◆ boundingRect()

◆ containsPoint()

◆ intersected()

◆ intersects()

◆ operator QVariant()

◆ point() [1/2]

◆ point() [2/2]

◆ putPoints() [1/3]

◆ putPoints() [2/3]

◆ putPoints() [3/3]

◆ setPoint() [1/2]

◆ setPoint() [2/2]

◆ setPoints() [1/2]

◆ setPoints() [2/2]

◆ subtracted()

◆ swap()

◆ translate() [1/2]

◆ translate() [2/2]

◆ translated() [1/2]

◆ translated() [2/2]

◆ united()

Friends And Related Function Documentation

◆ operator<<()

◆ operator>>()