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

#include <qpolygon.h>

Inheritance diagram for QPolygon:

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

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

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

	operator QVariant () const
	Returns the polygon as a QVariant. More...

void	point (int i, int x, int y) const
	Extracts the coordinates of the point at the given index to {x} and *{y} (if they are valid pointers). More...

QPoint	point (int i) const
	Returns the point at the given index. More...

void	putPoints (int index, int nPoints, const int *points)
	Copies nPoints points from the points coord array into this point array, and resizes the point array if `index+nPoints` exceeds the size of the array. More...

void	putPoints (int index, int nPoints, int firstx, int firsty,...)
	Copies nPoints points from the variable argument list into this polygon from the given index. More...

void	putPoints (int index, int nPoints, const QPolygon &from, int fromIndex=0)
	Copies nPoints points from the given fromIndex ( 0 by default) in fromPolygon into this polygon, starting at the specified index. More...

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

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

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

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

	QPolygon (const QRect &r, bool closed=false)
	Constructs a polygon from the given rectangle. More...

	QPolygon (int nPoints, const int *points)
	Constructs a point array with nPoints points, taken from the points array. More...

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

void	setPoint (int index, const QPoint &p)
	Sets the point at the given index to the given point. More...

void	setPoints (int nPoints, const int *points)
	Resizes the polygon to nPoints and populates it with the given points. More...

void	setPoints (int nPoints, int firstx, int firsty,...)
	Resizes the polygon to nPoints and populates it with the points specified by the variable argument list. More...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

const QPoint &	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...

QPoint &	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 QPoint &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 QPoint &t)
	Inserts value at index position i in the vector. More...

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

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

iterator	insert (iterator before, const QPoint &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< QPoint > &other) const

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

const QPoint &	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 QPoint &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< QPoint >	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< QPoint > &v) const
	Returns true if other is not equal to this vector; otherwise returns false. More...

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

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

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

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

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

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

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

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

const QPoint &	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 QPoint &t)
	Inserts value at the beginning of the vector. More...

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

void	push_front (const QPoint &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 QPoint &t)
	Constructs a vector with an initial size of size elements. More...

	QVector (const QVector< QPoint > &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 QPoint &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 QPoint &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< QPoint > &other)
	Swaps vector other with this vector. More...

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

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

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

QPoint	value (int i, const QPoint &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 QPolygon &polygon)
	Writes the given polygon to the given stream, and returns a reference to the stream. More...

QDataStream &	operator>> (QDataStream &stream, QPolygon &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< QPoint >
QDataStream &	operator<< (QDataStream &out, const QVector< QPoint > &vector)
	Writes the vector vector to stream out. More...

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

Additional Inherited Members
Public Types inherited from QVector< QPoint >
typedef const QPoint *	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 QPoint *	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 QPoint	value_type
	Typedef for T. More...

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

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

Public Variables inherited from QVector< QPoint >
QVectorData *	d

Data *	p

Detailed Description

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

Note: This class or function is reentrant.

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 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 QMatrix::map() function for more general transformations of QPolygons.

The QPolygon class is Implicit Data Sharing.

See also: QVector, QPolygonF, QLine

Definition at line 60 of file qpolygon.h.

Constructors and Destructors

◆ QPolygon() [1/6]

QPolygon::QPolygon ( )

inline

Constructs a polygon with no points.

See also: QVector::isEmpty()

Definition at line 63 of file qpolygon.h.

63 {}

◆ ~QPolygon()

QPolygon::~QPolygon ( )

inline

Destroys the polygon.

Definition at line 64 of file qpolygon.h.

64 {}

◆ QPolygon() [2/6]

QPolygon::QPolygon ( int size )

inline

Constructs a polygon of the given size.

Creates an empty polygon if size == 0.

See also: QVector::isEmpty()

Definition at line 99 of file qpolygon.h.

99 : QVector<QPoint>(asize) {}

QVector< QPoint >

◆ QPolygon() [3/6]

QPolygon::QPolygon ( const QPolygon & polygon )

inline

Constructs a copy of the given polygon.

See also: setPoints()

Definition at line 66 of file qpolygon.h.

66 : QVector<QPoint>(a) {}

a

long ASN1_INTEGER_get ASN1_INTEGER * a

Definition: qsslsocket_openssl_symbols.cpp:104

QVector< QPoint >

◆ QPolygon() [4/6]

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

inline

Constructs a polygon containing the specified points.

See also: setPoints()

Definition at line 67 of file qpolygon.h.

67 : QVector<QPoint>(v) {}

QVector< QPoint >

◆ QPolygon() [5/6]

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 194 of file qpolygon.cpp.

 {
     reserve(closed ? 5 : 4);
     *this << QPoint(r.x(), r.y())
           << QPoint(r.x() + r.width(), r.y())
           << QPoint(r.x() + r.width(), r.y() + r.height())
           << QPoint(r.x(), r.y() + r.height());
     if (closed)
         *this << QPoint(r.left(), r.top());
 }

◆ QPolygon() [6/6]

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

Constructs a point array with nPoints points, taken from the points array.

Warning: This function is not part of the public interface.

Equivalent to setPoints(nPoints, points).

Definition at line 216 of file qpolygon.cpp.

 {
     setPoints(nPoints, points);
 }

Functions

◆ 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: QVector::isEmpty()

Definition at line 492 of file qpolygon.cpp.

Referenced by QWindowsStyle::drawPrimitive(), QX11PaintEnginePrivate::fillPolygon_dev(), and QPolygonF::isClosed().

 {
     if (isEmpty())
         return QRect(0, 0, 0, 0);
     register const QPoint *pd = constData();
     int 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 QRect(QPoint(minx,miny), QPoint(maxx,maxy));
 }

◆ containsPoint()

bool QPolygon::containsPoint	(	const QPoint &	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 974 of file qpolygon.cpp.

Referenced by QPolygonF::isClosed().

 {
     if (isEmpty())
         return false;
 
     int winding_number = 0;
 
     QPoint last_pt = at(0);
     QPoint last_start = at(0);
     for (int i = 1; i < size(); ++i) {
         const QPoint &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()

QPolygon QPolygon::intersected ( const QPolygon & 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 1032 of file qpolygon.cpp.

Referenced by QPolygonF::isClosed().

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

◆ operator QVariant()

QPolygon::operator QVariant ( ) const

Returns the polygon as a QVariant.

Definition at line 806 of file qpolygon.cpp.

 {
     return QVariant(QVariant::Polygon, this);
 }

◆ point() [1/2]

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 297 of file qpolygon.cpp.

Referenced by QCommonStyle::drawControl().

 {
     QPoint p = at(index);
     if (x)
         *x = (int)p.x();
     if (y)
         *y = (int)p.y();
 }

◆ point() [2/2]

QPoint QPolygon::point ( int index ) const

inline

Returns the point at the given index.

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 123 of file qpolygon.h.

124 { return at(index); }

QVector< QPoint >::at

const QPoint & at(int i) const

Returns the item at index position i in the vector.

Definition: qvector.h:350

index

quint16 index

Definition: qfontsubset.cpp:116

◆ putPoints() [1/3]

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

Copies nPoints points from the points coord array into this point array, and resizes the point array if index+nPoints exceeds the size of the array.

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

Warning: This function is not part of the public interface.

See also: setPoint()

Definition at line 406 of file qpolygon.cpp.

Referenced by QMotifStyle::drawPrimitive(), and qDrawPlainRect().

 {
     if (index + nPoints > size())
         resize(index + nPoints);
     int i = index;
     while (nPoints--) {
         setPoint(i++, *points, *(points+1));
         points += 2;
     }
 }

◆ putPoints() [2/3]

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:

        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);

See also: setPoints()

Definition at line 438 of file qpolygon.cpp.

 {
     va_list ap;
     if (index + nPoints > size())
         resize(index + nPoints);
     if (nPoints <= 0)
         return;
     setPoint(index, firstx, firsty);
     int i = index, x, y;
     va_start(ap, firsty);
     while (--nPoints) {
         x = va_arg(ap, int);
         y = va_arg(ap, int);
         setPoint(++i, x, y);
     }
     va_end(ap);
 }

◆ putPoints() [3/3]

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

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

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

For example:

        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);

Definition at line 471 of file qpolygon.cpp.

 {
     if (index + nPoints > size())
         resize(index + nPoints);
     if (nPoints <= 0)
         return;
     int n = 0;
     while(n < nPoints) {
         setPoint(index + n, from[fromIndex+n]);
         ++n;
     }
 }

◆ setPoint() [1/2]

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

inline

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

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

Definition at line 120 of file qpolygon.h.

Referenced by addPoint(), QWindowsStyle::drawComplexControl(), QCommonStyle::drawControl(), QCommonStyle::drawPrimitive(), QCDEStyle::drawPrimitive(), QMotifStyle::drawPrimitive(), putPoints(), qDrawPlainRect(), rot(), and setPoints().

121 { (*this)[index] = QPoint(x, y); }

QPoint

The QPoint class defines a point in the plane using integer precision.

Definition: qpoint.h:53

index

quint16 index

Definition: qfontsubset.cpp:116

◆ setPoint() [2/2]

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

inline

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

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 117 of file qpolygon.h.

118 { (*this)[index] = pt; }

index

quint16 index

Definition: qfontsubset.cpp:116

◆ 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):

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

See also: setPoint() putPoints()

Definition at line 350 of file qpolygon.cpp.

Referenced by QWindowsCEStyle::drawComplexControl(), QWindowsMobileStyle::drawComplexControl(), QWindowsStyle::drawComplexControl(), QMotifStyle::drawComplexControl(), QMotifStyle::drawControl(), QCommonStyle::drawPrimitive(), QCDEStyle::drawPrimitive(), QWindowsStyle::drawPrimitive(), QMotifStyle::drawPrimitive(), QMatrix::mapToPolygon(), QTransform::mapToPolygon(), QColorLuminancePicker::paintEvent(), qDrawPlainRect(), qDrawShadeLine(), and QPolygon().

 {
     resize(nPoints);
     int i = 0;
     while (nPoints--) {
         setPoint(i++, *points, *(points+1));
         points += 2;
     }
 }

◆ setPoints() [2/2]

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

Resizes the polygon to nPoints and populates it with the points specified by the variable argument list.

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

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);

Definition at line 377 of file qpolygon.cpp.

 {
     va_list ap;
     resize(nPoints);
     setPoint(0, firstx, firsty);
     int i = 0, x, y;
     va_start(ap, firsty);
     while (--nPoints) {
         x = va_arg(ap, int);
         y = va_arg(ap, int);
         setPoint(++i, x, y);
     }
     va_end(ap);
 }

◆ subtracted()

QPolygon QPolygon::subtracted ( const QPolygon & 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 1053 of file qpolygon.cpp.

Referenced by QPolygonF::isClosed().

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

◆ swap()

void QPolygon::swap ( QPolygon & other )

inline

Swaps polygon other with this polygon.

Since: 4.8

This operation is very fast and never fails.

Definition at line 70 of file qpolygon.h.

70 { QVector<QPoint>::swap(other); } // prevent QVector<QPoint><->QPolygon swaps

QVector::swap

void swap(QVector< T > &other)

Swaps vector other with this vector.

Definition: qvector.h:130

◆ translate() [1/2]

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

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

See also: translated()

Definition at line 238 of file qpolygon.cpp.

Referenced by QCommonStyle::drawControl(), QCommonStyle::drawPrimitive(), QCDEStyle::drawPrimitive(), QMotifStyle::drawPrimitive(), qDrawPlainRect(), QPolygonF::swap(), translate(), and translated().

 {
     if (dx == 0 && dy == 0)
         return;
 
     register QPoint *p = data();
     register int i = size();
     QPoint pt(dx, dy);
     while (i--) {
         *p += pt;
         ++p;
     }
 }

◆ translate() [2/2]

void QPolygon::translate ( const QPoint & offset )

inline

Translates all points in the polygon by the given offset.

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 126 of file qpolygon.h.

127 { translate(offset.x(), offset.y()); }

QPolygon::translate

void translate(int dx, int dy)

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

Definition: qpolygon.cpp:238

QPoint::y

int y() const

Returns the y coordinate of this point.

Definition: qpoint.h:131

QPoint::x

int x() const

Returns the x coordinate of this point.

Definition: qpoint.h:128

◆ translated() [1/2]

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 270 of file qpolygon.cpp.

Referenced by QTransform::map(), QPolygonF::swap(), and translated().

 {
     QPolygon copy(*this);
     copy.translate(dx, dy);
     return copy;
 }

◆ translated() [2/2]

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

inline

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

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 129 of file qpolygon.h.

130 { return translated(offset.x(), offset.y()); }

QPolygon::translated

QPolygon translated(int dx, int dy) const

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

Definition: qpolygon.cpp:270

QPoint::y

int y() const

Returns the y coordinate of this point.

Definition: qpoint.h:131

QPoint::x

int x() const

Returns the x coordinate of this point.

Definition: qpoint.h:128

◆ united()

QPolygon QPolygon::united ( const QPolygon & 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, and implicitly close the polygon.

See also: intersected(), subtracted()

Definition at line 1012 of file qpolygon.cpp.

Referenced by QPolygonF::isClosed().

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

Friends and Related Functions

◆ operator<<()

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

Since: 4.4

See also: {Serializing Qt Data Types}

Definition at line 828 of file qpolygon.cpp.

Referenced by QPolygon().

 {
     const QVector<QPoint> &v = a;
     return s << v;
 }

◆ operator>>()

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

Since: 4.4

See also: {Serializing Qt Data Types}

Definition at line 847 of file qpolygon.cpp.

Referenced by QPolygon().

 {
     QVector<QPoint> &v = a;
     return s >> v;
 }

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

◆ QPolygon() [1/6]

◆ ~QPolygon()

◆ QPolygon() [2/6]

◆ QPolygon() [3/6]

◆ QPolygon() [4/6]

◆ QPolygon() [5/6]

◆ QPolygon() [6/6]

Functions

◆ boundingRect()

◆ containsPoint()

◆ intersected()

◆ 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 Functions

◆ operator<<()

◆ operator>>()