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

#include <qpolygon.h>

Inheritance diagram for QPolygonF:

Public Functions
QRectF	boundingRect () const
	Returns the bounding rectangle of the polygon, or QRectF(0,0,0,0) if the polygon is empty. More...

bool	containsPoint (const QPointF &pt, Qt::FillRule fillRule) const
	Returns true if the given point is inside the polygon according to the specified fillRule; otherwise returns false. More...

QPolygonF	intersected (const QPolygonF &r) const
	Returns a polygon which is the intersection of this polygon and r. More...

bool	isClosed () const
	Returns true if the polygon is closed; otherwise returns false. More...

	QPolygonF ()
	Constructs a polygon with no points. More...

	QPolygonF (int size)
	Constructs a polygon of the given size. More...

	QPolygonF (const QPolygonF &a)
	Constructs a copy of the given polygon. More...

	QPolygonF (const QVector< QPointF > &v)
	Constructs a polygon containing the specified points. More...

	QPolygonF (const QRectF &r)
	Constructs a closed polygon from the specified rectangle. More...

	QPolygonF (const QPolygon &a)
	Constructs a float based polygon from the specified integer based polygon. More...

QPolygonF	subtracted (const QPolygonF &r) const
	Returns a polygon which is r subtracted from this polygon. More...

void	swap (QPolygonF &other)
	Swaps polygon other with this polygon. More...

QPolygon	toPolygon () const
	Creates and returns a QPolygon by converting each QPointF to a QPoint. More...

void	translate (qreal dx, qreal dy)
	Translates all points in the polygon by ({dx}, {dy}). More...

void	translate (const QPointF &offset)
	Translate all points in the polygon by the given offset. More...

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

QPolygonF	translated (const QPointF &offset) const
	Returns a copy of the polygon that is translated by the given offset. More...

QPolygonF	united (const QPolygonF &r) const
	Returns a polygon which is the union of this polygon and r. More...

	~QPolygonF ()
	Destroys the polygon. More...

Public Functions inherited from QVector< QPointF >
void	append (const QPointF &t)
	Inserts value at the end of the vector. More...

const QPointF &	at (int i) const
	Returns the item at index position i in the vector. More...

reference	back ()
	This function is provided for STL compatibility. More...

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

iterator	begin ()
	Returns an STL-style iterator pointing to the first item in the vector. More...

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

int	capacity () const
	Returns the maximum number of items that can be stored in the vector without forcing a reallocation. More...

void	clear ()
	Removes all the elements from the vector and releases the memory used by the vector. More...

const_iterator	constBegin () const
	Returns a const STL-style iterator pointing to the first item in the vector. More...

const QPointF *	constData () const
	Returns a const pointer to the data stored in the vector. More...

const_iterator	constEnd () const
	Returns a const STL-style iterator pointing to the imaginary item after the last item in the vector. More...

bool	contains (const QPointF &t) const
	Returns true if the vector contains an occurrence of value; otherwise returns false. More...

int	count (const QPointF &t) const
	Returns the number of occurrences of value in the vector. More...

int	count () const
	Same as size(). More...

QPointF *	data ()
	Returns a pointer to the data stored in the vector. More...

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

void	detach ()

bool	empty () const
	This function is provided for STL compatibility. More...

iterator	end ()
	Returns an STL-style iterator pointing to the imaginary item after the last item in the vector. More...

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

bool	endsWith (const QPointF &t) const
	Returns true if this vector is not empty and its last item is equal to value; otherwise returns false. More...

iterator	erase (iterator begin, iterator end)
	Removes all the items from begin up to (but not including) end. More...

iterator	erase (iterator pos)
	Removes the item pointed to by the iterator pos from the vector, and returns an iterator to the next item in the vector (which may be end()). More...

QVector< QPointF > &	fill (const QPointF &t, int size=-1)
	Assigns value to all items in the vector. More...

QPointF &	first ()
	Returns a reference to the first item in the vector. More...

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

QPointF &	front ()
	This function is provided for STL compatibility. More...

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

int	indexOf (const QPointF &t, int from=0) const
	Returns the index position of the first occurrence of value in the vector, searching forward from index position from. More...

void	insert (int i, const QPointF &t)
	Inserts value at index position i in the vector. More...

void	insert (int i, int n, const QPointF &t)
	Inserts count copies of value at index position i in the vector. More...

iterator	insert (iterator before, int n, const QPointF &x)
	Inserts count copies of value in front of the item pointed to by the iterator before. More...

iterator	insert (iterator before, const QPointF &x)
	Inserts value in front of the item pointed to by the iterator before. More...

bool	isDetached () const

bool	isEmpty () const
	Returns true if the vector has size 0; otherwise returns false. More...

bool	isSharedWith (const QVector< QPointF > &other) const

QPointF &	last ()
	Returns a reference to the last item in the vector. More...

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

int	lastIndexOf (const QPointF &t, int from=-1) const
	Returns the index position of the last occurrence of the value value in the vector, searching backward from index position from. More...

QVector< QPointF >	mid (int pos, int length=-1) const
	Returns a vector whose elements are copied from this vector, starting at position pos. More...

bool	operator!= (const QVector< QPointF > &v) const
	Returns true if other is not equal to this vector; otherwise returns false. More...

QVector< QPointF >	operator+ (const QVector< QPointF > &l) const
	Returns a vector that contains all the items in this vector followed by all the items in the other vector. More...

QVector< QPointF > &	operator+= (const QVector< QPointF > &l)
	Appends the items of the other vector to this vector and returns a reference to this vector. More...

QVector< QPointF > &	operator+= (const QPointF &t)
	Appends value to the vector. More...

QVector< QPointF > &	operator<< (const QVector< QPointF > &l)
	Appends other to the vector and returns a reference to the vector. More...

QVector< QPointF > &	operator<< (const QPointF &t)
	Appends value to the vector and returns a reference to this vector. More...

QVector< QPointF > &	operator= (const QVector< QPointF > &v)
	Assigns other to this vector and returns a reference to this vector. More...

bool	operator== (const QVector< QPointF > &v) const
	Returns true if other is equal to this vector; otherwise returns false. More...

QPointF &	operator[] (int i)
	Returns the item at index position i as a modifiable reference. More...

const QPointF &	operator[] (int i) const
	Same as at(i). More...

void	pop_back ()
	This function is provided for STL compatibility. More...

void	pop_front ()
	This function is provided for STL compatibility. More...

void	prepend (const QPointF &t)
	Inserts value at the beginning of the vector. More...

void	push_back (const QPointF &t)
	This function is provided for STL compatibility. More...

void	push_front (const QPointF &t)
	This function is provided for STL compatibility. More...

	QVector ()
	Constructs an empty vector. More...

	QVector (int size)
	Constructs a vector with an initial size of size elements. More...

	QVector (int size, const QPointF &t)
	Constructs a vector with an initial size of size elements. More...

	QVector (const QVector< QPointF > &v)
	Constructs a copy of other. More...

void	remove (int i)
	Removes the element at index position i. More...

void	remove (int i, int n)
	Removes count elements from the middle of the vector, starting at index position i. More...

void	replace (int i, const QPointF &t)
	Replaces the item at index position i with value. More...

void	reserve (int size)
	Attempts to allocate memory for at least size elements. More...

void	resize (int size)
	Sets the size of the vector to size. More...

void	setSharable (bool sharable)

int	size () const
	Returns the number of items in the vector. More...

void	squeeze ()
	Releases any memory not required to store the items. More...

bool	startsWith (const QPointF &t) const
	Returns true if this vector is not empty and its first item is equal to value; otherwise returns false. More...

void	swap (QVector< QPointF > &other)
	Swaps vector other with this vector. More...

QList< QPointF >	toList () const
	Returns a QList object with the data contained in this QVector. More...

std::vector< QPointF >	toStdVector () const
	Returns a std::vector object with the data contained in this QVector. More...

QPointF	value (int i) const
	Returns the value at index position i in the vector. More...

QPointF	value (int i, const QPointF &defaultValue) const
	If the index i is out of bounds, the function returns defaultValue. More...

	~QVector ()
	Destroys the vector. More...

Related Functions
(Note that these are not member functions.)
QDataStream &	operator<< (QDataStream &stream, const QPolygonF &polygon)
	Writes the given polygon to the given stream, and returns a reference to the stream. More...

QDataStream &	operator>> (QDataStream &stream, QPolygonF &polygon)
	Reads a polygon from the given stream into the given polygon, and returns a reference to the stream. More...

Related Functions inherited from QVector< QPointF >
QDataStream &	operator<< (QDataStream &out, const QVector< QPointF > &vector)
	Writes the vector vector to stream out. More...

QDataStream &	operator>> (QDataStream &in, QVector< QPointF > &vector)
	Reads a vector from stream in into vector. More...

Additional Inherited Members
Public Types inherited from QVector< QPointF >
typedef const QPointF *	const_iterator
	The QVector::const_iterator typedef provides an STL-style const iterator for QVector and QStack. More...

typedef const value_type *	const_pointer
	Typedef for const T *. More...

typedef const value_type &	const_reference
	Typedef for T &. More...

typedef const_iterator	ConstIterator
	Qt-style synonym for QVector::const_iterator. More...

typedef qptrdiff	difference_type
	Typedef for ptrdiff_t. More...

typedef QPointF *	iterator
	The QVector::iterator typedef provides an STL-style non-const iterator for QVector and QStack. More...

typedef iterator	Iterator
	Qt-style synonym for QVector::iterator. More...

typedef value_type *	pointer
	Typedef for T *. More...

typedef value_type &	reference
	Typedef for T &. More...

typedef int	size_type
	Typedef for int. More...

typedef QPointF	value_type
	Typedef for T. More...

Static Public Functions inherited from QVector< QPointF >
static QVector< QPointF >	fromList (const QList< QPointF > &list)
	Returns a QVector object with the data contained in list. More...

static QVector< QPointF >	fromStdVector (const std::vector< QPointF > &vector)
	Returns a QVector object with the data contained in vector. More...

Public Variables inherited from QVector< QPointF >
QVectorData *	d

Data *	p

Detailed Description

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

Note: This class or function is reentrant.

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 Implicit Data Sharing.

See also: QVector, QPolygon, QLineF

Definition at line 134 of file qpolygon.h.

Constructors and Destructors

◆ QPolygonF() [1/6]

QPolygonF::QPolygonF ( )

inline

Constructs a polygon with no points.

See also: QVector::isEmpty()

Definition at line 137 of file qpolygon.h.

137 {}

◆ ~QPolygonF()

QPolygonF::~QPolygonF ( )

inline

Destroys the polygon.

Definition at line 138 of file qpolygon.h.

138 {}

◆ QPolygonF() [2/6]

QPolygonF::QPolygonF ( int size )

inline

Constructs a polygon of the given size.

Creates an empty polygon if size == 0.

See also: QVector::isEmpty()

Definition at line 165 of file qpolygon.h.

165 : QVector<QPointF>(asize) {}

QVector< QPointF >

◆ QPolygonF() [3/6]

QPolygonF::QPolygonF ( const QPolygonF & a )

inline

Constructs a copy of the given polygon.

Definition at line 140 of file qpolygon.h.

140 : QVector<QPointF>(a) {}

a

long ASN1_INTEGER_get ASN1_INTEGER * a

Definition: qsslsocket_openssl_symbols.cpp:104

QVector< QPointF >

◆ QPolygonF() [4/6]

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

inline

Constructs a polygon containing the specified points.

Definition at line 141 of file qpolygon.h.

141 : QVector<QPointF>(v) {}

QVector< QPointF >

◆ QPolygonF() [5/6]

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()

Definition at line 626 of file qpolygon.cpp.

 {
     reserve(5);
     append(QPointF(r.x(), r.y()));
     append(QPointF(r.x() + r.width(), r.y()));
     append(QPointF(r.x() + r.width(), r.y() + r.height()));
     append(QPointF(r.x(), r.y() + r.height()));
     append(QPointF(r.x(), r.y()));
 }

◆ QPolygonF() [6/6]

QPolygonF::QPolygonF ( const QPolygon & polygon )

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

See also: toPolygon()

Definition at line 648 of file qpolygon.cpp.

 {
     reserve(a.size());
     for (int i=0; i<a.size(); ++i)
         append(a.at(i));
 }

Functions

◆ boundingRect()

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()

Definition at line 742 of file qpolygon.cpp.

Referenced by QGLPathMaskGenerator::computeScreenRect(), QPicturePaintEngine::drawPolygon(), QGraphicsSceneIndex::items(), QMacPixmapData::macCreatePixels(), QGraphicsViewPrivate::mapToScene(), QAccessibleDial::rect(), QGraphicsView::render(), QPainterPath::toFillPolygons(), QX11PixmapData::transformed(), and QImage::transformed().

 {
     if (isEmpty())
         return QRectF(0, 0, 0, 0);
     register const QPointF *pd = constData();
     qreal minx, maxx, miny, maxy;
     minx = maxx = pd->x();
     miny = maxy = pd->y();
     ++pd;
     for (int i = 1; i < size(); ++i) {
         if (pd->x() < minx)
             minx = pd->x();
         else if (pd->x() > maxx)
             maxx = pd->x();
         if (pd->y() < miny)
             miny = pd->y();
         else if (pd->y() > maxy)
             maxy = pd->y();
         ++pd;
     }
     return QRectF(minx,miny, maxx - minx, maxy - miny);
 }

◆ containsPoint()

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.

Since: 4.3

Definition at line 940 of file qpolygon.cpp.

 {
     if (isEmpty())
         return false;
 
     int winding_number = 0;
 
     QPointF last_pt = at(0);
     QPointF last_start = at(0);
     for (int i = 1; i < size(); ++i) {
         const QPointF &e = at(i);
         qt_polygon_isect_line(last_pt, e, pt, &winding_number);
         last_pt = e;
     }
 
     // implicitly close last subpath
     if (last_pt != last_start)
         qt_polygon_isect_line(last_pt, last_start, pt, &winding_number);
 
     return (fillRule == Qt::WindingFill
             ? (winding_number != 0)
             : ((winding_number % 2) != 0));
 }

◆ intersected()

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

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

Since: 4.3

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

Definition at line 1096 of file qpolygon.cpp.

 {
     QPainterPath subject; subject.addPolygon(*this);
     QPainterPath clip; clip.addPolygon(r);
 
     return subject.intersected(clip).toFillPolygon();
 }

◆ isClosed()

bool QPolygonF::isClosed ( ) const

inline

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(), QVector::last()

Definition at line 154 of file qpolygon.h.

Referenced by QPainterPath::toFillPolygon(), and QPainterPath::toFillPolygons().

154 { return !isEmpty() && first() == last(); }

QVector< QPointF >::first

QPointF & first()

Returns a reference to the first item in the vector.

Definition: qvector.h:260

QVector< QPointF >::last

QPointF & last()

Returns a reference to the last item in the vector.

Definition: qvector.h:262

QVector< QPointF >::isEmpty

bool isEmpty() const

Returns true if the vector has size 0; otherwise returns false.

Definition: qvector.h:139

◆ subtracted()

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

Returns a polygon which is r subtracted from this polygon.

Since: 4.3

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

Definition at line 1117 of file qpolygon.cpp.

 {
     QPainterPath subject; subject.addPolygon(*this);
     QPainterPath clip; clip.addPolygon(r);
     return subject.subtracted(clip).toFillPolygon();
 }

◆ swap()

void QPolygonF::swap ( QPolygonF & other )

inline

Swaps polygon other with this polygon.

Since: 4.8

This operation is very fast and never fails.

Definition at line 144 of file qpolygon.h.

144 { QVector<QPointF>::swap(other); } // prevent QVector<QPointF><->QPolygonF swaps

QVector::swap

void swap(QVector< T > &other)

Swaps vector other with this vector.

Definition: qvector.h:130

◆ toPolygon()

QPolygon QPolygonF::toPolygon ( ) const

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

See also: QPointF::toPoint()

Definition at line 772 of file qpolygon.cpp.

Referenced by QOpenGLPaintEngine::clip(), clipTransformIsSimple(), QPolygon::intersected(), QMatrix::map(), QTransform::map(), QPolygon::subtracted(), QX11PaintEnginePrivate::systemStateChanged(), QPolygon::united(), QCoreGraphicsPaintEngine::updateClipPath(), QX11PaintEngine::updateState(), and QOpenGLPaintEngine::updateState().

 {
     QPolygon a;
     a.reserve(size());
     for (int i=0; i<size(); ++i)
         a.append(at(i).toPoint());
     return a;
 }

◆ translate() [1/2]

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

inline

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

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

See also: translated()

Definition at line 179 of file qpolygon.h.

Referenced by translated().

180 { translate(QPointF(dx, dy)); }

QPointF

The QPointF class defines a point in the plane using floating point precision.

Definition: qpoint.h:214

QPolygonF::translate

void translate(qreal dx, qreal dy)

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

Definition: qpolygon.h:179

◆ translate() [2/2]

void QPolygonF::translate ( const QPointF & offset )

Translate all points in the polygon by the given offset.

See also: translated()

Definition at line 671 of file qpolygon.cpp.

 {
     if (offset.isNull())
         return;
 
     register QPointF *p = data();
     register int i = size();
     while (i--) {
         *p += offset;
         ++p;
     }
 }

◆ translated() [1/2]

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

inline

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

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

See also: translate()

Definition at line 182 of file qpolygon.h.

Referenced by QTransform::map(), QGraphicsItem::mapFromParent(), QGraphicsItem::mapFromScene(), QGraphicsItem::mapToParent(), and QGraphicsItem::mapToScene().

183 { return translated(QPointF(dx, dy)); }

QPointF

The QPointF class defines a point in the plane using floating point precision.

Definition: qpoint.h:214

QPolygonF::translated

QPolygonF translated(qreal dx, qreal dy) const

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

Definition: qpolygon.h:182

◆ translated() [2/2]

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

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

Since: 4.6

See also: translate()

Definition at line 702 of file qpolygon.cpp.

 {
     QPolygonF copy(*this);
     copy.translate(offset);
     return copy;
 }

◆ united()

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

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

Since: 4.3

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

See also: intersected(), subtracted()

Definition at line 1075 of file qpolygon.cpp.

 {
     QPainterPath subject; subject.addPolygon(*this);
     QPainterPath clip; clip.addPolygon(r);
 
     return subject.united(clip).toFillPolygon();
 }

Friends and Related Functions

◆ operator<<()

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

See also: {Serializing Qt Data Types}

Definition at line 871 of file qpolygon.cpp.

Referenced by QPolygonF().

 {
     quint32 len = a.size();
     uint i;
 
     s << len;
     for (i = 0; i < len; ++i)
         s << a.at(i);
     return s;
 }

◆ operator>>()

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

See also: {Serializing Qt Data Types}

Definition at line 895 of file qpolygon.cpp.

Referenced by QPolygonF().

 {
     quint32 len;
     uint i;
 
     s >> len;
     a.reserve(a.size() + (int)len);
     QPointF p;
     for (i = 0; i < len; ++i) {
         s >> p;
         a.insert(i, p);
     }
     return s;
 }

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

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

Public Functions

Related Functions

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ QPolygonF() [1/6]

◆ ~QPolygonF()

◆ QPolygonF() [2/6]

◆ QPolygonF() [3/6]

◆ QPolygonF() [4/6]

◆ QPolygonF() [5/6]

◆ QPolygonF() [6/6]

Functions

◆ boundingRect()

◆ containsPoint()

◆ intersected()

◆ isClosed()

◆ subtracted()

◆ swap()

◆ toPolygon()

◆ translate() [1/2]

◆ translate() [2/2]

◆ translated() [1/2]

◆ translated() [2/2]

◆ united()

Friends and Related Functions

◆ operator<<()

◆ operator>>()