summaryrefslogtreecommitdiffstats
path: root/src/gui/painting/qpolygon.cpp
diff options
context:
space:
mode:
authorLars Knoll <lars.knoll@nokia.com>2009-03-23 09:18:55 (GMT)
committerSimon Hausmann <simon.hausmann@nokia.com>2009-03-23 09:18:55 (GMT)
commite5fcad302d86d316390c6b0f62759a067313e8a9 (patch)
treec2afbf6f1066b6ce261f14341cf6d310e5595bc1 /src/gui/painting/qpolygon.cpp
downloadQt-e5fcad302d86d316390c6b0f62759a067313e8a9.zip
Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.gz
Qt-e5fcad302d86d316390c6b0f62759a067313e8a9.tar.bz2
Long live Qt 4.5!
Diffstat (limited to 'src/gui/painting/qpolygon.cpp')
-rw-r--r--src/gui/painting/qpolygon.cpp928
1 files changed, 928 insertions, 0 deletions
diff --git a/src/gui/painting/qpolygon.cpp b/src/gui/painting/qpolygon.cpp
new file mode 100644
index 0000000..87dae0f
--- /dev/null
+++ b/src/gui/painting/qpolygon.cpp
@@ -0,0 +1,928 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qpolygon.h"
+#include "qrect.h"
+#include "qdatastream.h"
+#include "qmatrix.h"
+#include "qdebug.h"
+#include "qpainterpath.h"
+#include "qvariant.h"
+#include "qpainterpath_p.h"
+#include "qbezier_p.h"
+
+#include <stdarg.h>
+
+QT_BEGIN_NAMESPACE
+
+//same as qt_painterpath_isect_line in qpainterpath.cpp
+static void qt_polygon_isect_line(const QPointF &p1, const QPointF &p2, const QPointF &pos,
+ int *winding)
+{
+ qreal x1 = p1.x();
+ qreal y1 = p1.y();
+ qreal x2 = p2.x();
+ qreal y2 = p2.y();
+ qreal y = pos.y();
+
+ int dir = 1;
+
+ if (qFuzzyCompare(y1, y2)) {
+ // ignore horizontal lines according to scan conversion rule
+ return;
+ } else if (y2 < y1) {
+ qreal x_tmp = x2; x2 = x1; x1 = x_tmp;
+ qreal y_tmp = y2; y2 = y1; y1 = y_tmp;
+ dir = -1;
+ }
+
+ if (y >= y1 && y < y2) {
+ qreal x = x1 + ((x2 - x1) / (y2 - y1)) * (y - y1);
+
+ // count up the winding number if we're
+ if (x<=pos.x()) {
+ (*winding) += dir;
+ }
+ }
+}
+
+/*!
+ \class QPolygon
+ \brief The QPolygon class provides a vector of points using
+ integer precision.
+
+ \reentrant
+
+ \ingroup multimedia
+ \ingroup shared
+
+ 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:
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 0
+
+ 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 \l {Implicit Data Sharing}{implicitly
+ shared}.
+
+ \sa QVector, QPolygonF, QLine
+*/
+
+
+/*****************************************************************************
+ QPolygon member functions
+ *****************************************************************************/
+
+/*!
+ \fn QPolygon::QPolygon()
+
+ Constructs a polygon with no points.
+
+ \sa QVector::isEmpty()
+*/
+
+/*!
+ \fn QPolygon::QPolygon(int size)
+
+ Constructs a polygon of the given \a size. Creates an empty
+ polygon if \a size == 0.
+
+ \sa QVector::isEmpty()
+*/
+
+/*!
+ \fn QPolygon::QPolygon(const QPolygon &polygon)
+
+ Constructs a copy of the given \a polygon.
+
+ \sa setPoints()
+*/
+
+/*!
+ \fn QPolygon::QPolygon(const QVector<QPoint> &points)
+
+ Constructs a polygon containing the specified \a points.
+
+ \sa setPoints()
+*/
+
+/*!
+ \fn QPolygon::QPolygon(const QRect &rectangle, bool closed)
+
+ Constructs a polygon from the given \a rectangle. If \a closed is
+ false, the polygon just contains the four points of the rectangle
+ ordered clockwise, otherwise the polygon's fifth point is set to
+ \a {rectangle}.topLeft().
+
+ Note that the bottom-right corner of the rectangle is located at
+ (rectangle.x() + rectangle.width(), rectangle.y() +
+ rectangle.height()).
+
+ \sa setPoints()
+*/
+
+QPolygon::QPolygon(const QRect &r, bool closed)
+{
+ 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());
+}
+
+/*!
+ \internal
+ Constructs a point array with \a nPoints points, taken from the
+ \a points array.
+
+ Equivalent to setPoints(nPoints, points).
+*/
+
+QPolygon::QPolygon(int nPoints, const int *points)
+{
+ setPoints(nPoints, points);
+}
+
+
+/*!
+ \fn QPolygon::~QPolygon()
+
+ Destroys the polygon.
+*/
+
+
+/*!
+ Translates all points in the polygon by (\a{dx}, \a{dy}).
+*/
+
+void QPolygon::translate(int dx, int dy)
+{
+ register QPoint *p = data();
+ register int i = size();
+ QPoint pt(dx, dy);
+ while (i--) {
+ *p += pt;
+ ++p;
+ }
+}
+
+/*!
+ \fn void QPolygon::translate(const QPoint &offset)
+ \overload
+
+ Translates all points in the polygon by the given \a offset.
+*/
+
+
+/*!
+ Extracts the coordinates of the point at the given \a index to
+ *\a{x} and *\a{y} (if they are valid pointers).
+
+ \sa setPoint()
+*/
+
+void QPolygon::point(int index, int *x, int *y) const
+{
+ QPoint p = at(index);
+ if (x)
+ *x = (int)p.x();
+ if (y)
+ *y = (int)p.y();
+}
+
+/*!
+ \fn QPoint QPolygon::point(int index) const
+ \overload
+
+ Returns the point at the given \a index.
+*/
+
+/*!
+ \fn void QPolygon::setPoint(int index, const QPoint &point)
+ \overload
+
+ Sets the point at the given \a index to the given \a point.
+*/
+
+/*!
+ \fn void QPolygon::setPoint(int index, int x, int y)
+
+ Sets the point at the given \a index to the point specified by
+ (\a{x}, \a{y}).
+
+ \sa point(), putPoints(), setPoints(),
+*/
+
+/*!
+ Resizes the polygon to \a nPoints and populates it with the given
+ \a points.
+
+ The example code creates a polygon with two points (10, 20) and
+ (30, 40):
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 2
+
+ \sa setPoint() putPoints()
+*/
+
+void QPolygon::setPoints(int nPoints, const int *points)
+{
+ resize(nPoints);
+ int i = 0;
+ while (nPoints--) {
+ setPoint(i++, *points, *(points+1));
+ points += 2;
+ }
+}
+
+/*!
+ \overload
+
+ Resizes the polygon to \a nPoints and populates it with the points
+ specified by the variable argument list. The points are given as a
+ sequence of integers, starting with \a firstx then \a firsty, and
+ so on.
+
+ The example code creates a polygon with two points (10, 20) and
+ (30, 40):
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 3
+*/
+
+void QPolygon::setPoints(int nPoints, int firstx, int firsty, ...)
+{
+ 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);
+}
+
+/*!
+ \overload
+ \internal
+
+ Copies \a nPoints points from the \a points coord array into this
+ point array, and resizes the point array if \c{index+nPoints}
+ exceeds the size of the array.
+
+ \sa setPoint()
+*/
+
+void QPolygon::putPoints(int index, int nPoints, const int *points)
+{
+ if (index + nPoints > size())
+ resize(index + nPoints);
+ int i = index;
+ while (nPoints--) {
+ setPoint(i++, *points, *(points+1));
+ points += 2;
+ }
+}
+
+/*!
+ Copies \a nPoints points from the variable argument list into this
+ polygon from the given \a index.
+
+ The points are given as a sequence of integers, starting with \a
+ firstx then \a firsty, and so on. The polygon is resized if
+ \c{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:
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 4
+
+ The following code has the same result, but here the putPoints()
+ function overwrites rather than extends:
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 5
+
+ \sa setPoints()
+*/
+
+void QPolygon::putPoints(int index, int nPoints, int firstx, int firsty, ...)
+{
+ 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);
+}
+
+
+/*!
+ \fn void QPolygon::putPoints(int index, int nPoints, const QPolygon &fromPolygon, int fromIndex)
+ \overload
+
+ Copies \a nPoints points from the given \a fromIndex ( 0 by
+ default) in \a fromPolygon into this polygon, starting at the
+ specified \a index. For example:
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 6
+*/
+
+void QPolygon::putPoints(int index, int nPoints, const QPolygon & from, int fromIndex)
+{
+ if (index + nPoints > size())
+ resize(index + nPoints);
+ if (nPoints <= 0)
+ return;
+ int n = 0;
+ while(n < nPoints) {
+ setPoint(index + n, from[fromIndex+n]);
+ ++n;
+ }
+}
+
+
+/*!
+ Returns the bounding rectangle of the polygon, or QRect(0, 0, 0,
+ 0) if the polygon is empty.
+
+ \sa QVector::isEmpty()
+*/
+
+QRect QPolygon::boundingRect() const
+{
+ 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));
+}
+
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug dbg, const QPolygon &a)
+{
+#ifndef Q_BROKEN_DEBUG_STREAM
+ dbg.nospace() << "QPolygon(";
+ for (int i = 0; i < a.count(); ++i)
+ dbg.nospace() << a.at(i);
+ dbg.nospace() << ')';
+ return dbg.space();
+#else
+ qWarning("This compiler doesn't support streaming QPolygon to QDebug");
+ return dbg;
+ Q_UNUSED(a);
+#endif
+}
+#endif
+
+
+/*!
+ \class QPolygonF
+ \brief The QPolygonF class provides a vector of points using
+ floating point precision.
+
+ \reentrant
+ \ingroup multimedia
+ \ingroup shared
+
+ A QPolygonF is a QVector<QPointF>. The easiest way to add points
+ to a QPolygonF is to use its streaming operator, as illustrated
+ below:
+
+ \snippet doc/src/snippets/polygon/polygon.cpp 1
+
+ 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 \l {Implicit Data Sharing}{implicitly
+ shared}.
+
+ \sa QVector, QPolygon, QLineF
+*/
+
+
+/*****************************************************************************
+ QPolygonF member functions
+ *****************************************************************************/
+
+/*!
+ \fn QPolygonF::QPolygonF()
+
+ Constructs a polygon with no points.
+
+ \sa QVector::isEmpty()
+*/
+
+/*!
+ \fn QPolygonF::QPolygonF(int size)
+
+ Constructs a polygon of the given \a size. Creates an empty
+ polygon if \a size == 0.
+
+ \sa QVector::isEmpty()
+*/
+
+/*!
+ \fn QPolygonF::QPolygonF(const QPolygonF &polygon)
+
+ Constructs a copy of the given \a polygon.
+*/
+
+/*!
+ \fn QPolygonF::QPolygonF(const QVector<QPointF> &points)
+
+ Constructs a polygon containing the specified \a points.
+*/
+
+/*!
+ \fn QPolygonF::QPolygonF(const QRectF &rectangle)
+
+ Constructs a closed polygon from the specified \a rectangle.
+
+ The polygon contains the four vertices of the rectangle in
+ clockwise order starting and ending with the top-left vertex.
+
+ \sa isClosed()
+*/
+
+QPolygonF::QPolygonF(const QRectF &r)
+{
+ 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()));
+}
+
+/*!
+ \fn QPolygonF::QPolygonF(const QPolygon &polygon)
+
+ Constructs a float based polygon from the specified integer based
+ \a polygon.
+
+ \sa toPolygon()
+*/
+
+QPolygonF::QPolygonF(const QPolygon &a)
+{
+ reserve(a.size());
+ for (int i=0; i<a.size(); ++i)
+ append(a.at(i));
+}
+
+/*!
+ \fn QPolygonF::~QPolygonF()
+
+ Destroys the polygon.
+*/
+
+
+/*!
+ Translate all points in the polygon by the given \a offset.
+*/
+
+void QPolygonF::translate(const QPointF &offset)
+{
+ register QPointF *p = data();
+ register int i = size();
+ while (i--) {
+ *p += offset;
+ ++p;
+ }
+}
+
+/*!
+ \fn void QPolygonF::translate(qreal dx, qreal dy)
+ \overload
+
+ Translates all points in the polygon by (\a{dx}, \a{dy}).
+*/
+
+/*!
+ \fn bool QPolygonF::isClosed() const
+
+ 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.
+
+ \sa QVector::first(), QVector::last()
+*/
+
+/*!
+ Returns the bounding rectangle of the polygon, or QRectF(0,0,0,0)
+ if the polygon is empty.
+
+ \sa QVector::isEmpty()
+*/
+
+QRectF QPolygonF::boundingRect() const
+{
+ 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);
+}
+
+/*!
+ Creates and returns a QPolygon by converting each QPointF to a
+ QPoint.
+
+ \sa QPointF::toPoint()
+*/
+
+QPolygon QPolygonF::toPolygon() const
+{
+ QPolygon a;
+ a.reserve(size());
+ for (int i=0; i<size(); ++i)
+ a.append(at(i).toPoint());
+ return a;
+}
+
+/*!
+ Returns the polygon as a QVariant
+*/
+QPolygon::operator QVariant() const
+{
+ return QVariant(QVariant::Polygon, this);
+}
+
+/*****************************************************************************
+ QPolygon stream functions
+ *****************************************************************************/
+#ifndef QT_NO_DATASTREAM
+/*!
+ \fn QDataStream &operator<<(QDataStream &stream, const QPolygon &polygon)
+ \since 4.4
+ \relates QPolygon
+
+ Writes the given \a polygon to the given \a stream, and returns a
+ reference to the stream.
+
+ \sa {Format of the QDataStream Operators}
+*/
+QDataStream &operator<<(QDataStream &s, const QPolygon &a)
+{
+ const QVector<QPoint> &v = a;
+ return s << v;
+}
+
+/*!
+ \fn QDataStream &operator>>(QDataStream &stream, QPolygon &polygon)
+ \since 4.4
+ \relates QPolygon
+
+ Reads a polygon from the given \a stream into the given \a
+ polygon, and returns a reference to the stream.
+
+ \sa {Format of the QDataStream Operators}
+*/
+QDataStream &operator>>(QDataStream &s, QPolygon &a)
+{
+ QVector<QPoint> &v = a;
+ return s >> v;
+}
+#endif
+
+/*****************************************************************************
+ QPolygonF stream functions
+ *****************************************************************************/
+#ifndef QT_NO_DATASTREAM
+/*!
+ \fn QDataStream &operator<<(QDataStream &stream, const QPolygonF &polygon)
+ \relates QPolygonF
+
+ Writes the given \a polygon to the given \a stream, and returns a
+ reference to the stream.
+
+ \sa {Format of the QDataStream Operators}
+*/
+
+QDataStream &operator<<(QDataStream &s, const QPolygonF &a)
+{
+ quint32 len = a.size();
+ uint i;
+
+ s << len;
+ for (i = 0; i < len; ++i)
+ s << a.at(i);
+ return s;
+}
+
+/*!
+ \fn QDataStream &operator>>(QDataStream &stream, QPolygonF &polygon)
+ \relates QPolygonF
+
+ Reads a polygon from the given \a stream into the given \a
+ polygon, and returns a reference to the stream.
+
+ \sa {Format of the QDataStream Operators}
+*/
+
+QDataStream &operator>>(QDataStream &s, QPolygonF &a)
+{
+ 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;
+}
+#endif //QT_NO_DATASTREAM
+
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug dbg, const QPolygonF &a)
+{
+#ifndef Q_BROKEN_DEBUG_STREAM
+ dbg.nospace() << "QPolygonF(";
+ for (int i = 0; i < a.count(); ++i)
+ dbg.nospace() << a.at(i);
+ dbg.nospace() << ')';
+ return dbg.space();
+#else
+ qWarning("This compiler doesn't support streaming QPolygonF to QDebug");
+ return dbg;
+ Q_UNUSED(a);
+#endif
+}
+#endif
+
+
+/*!
+ \since 4.3
+
+ \fn bool QPolygonF::containsPoint(const QPointF &point, Qt::FillRule fillRule) const
+
+ Returns true if the given \a point is inside the polygon according to
+ the specified \a fillRule; otherwise returns false.
+*/
+bool QPolygonF::containsPoint(const QPointF &pt, Qt::FillRule fillRule) const
+{
+ 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));
+}
+
+/*!
+ \since 4.3
+
+ \fn bool QPolygon::containsPoint(const QPoint &point, Qt::FillRule fillRule) const
+ Returns true if the given \a point is inside the polygon according to
+ the specified \a fillRule; otherwise returns false.
+*/
+bool QPolygon::containsPoint(const QPoint &pt, Qt::FillRule fillRule) const
+{
+ 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));
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is the union of this polygon and \a r.
+
+ Set operations on polygons, will treat the polygons as areas, and
+ implicitly close the polygon.
+
+ \sa intersected(), subtracted()
+*/
+
+QPolygon QPolygon::united(const QPolygon &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+
+ return subject.united(clip).toFillPolygon().toPolygon();
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is the intersection of this polygon and \a r.
+
+ Set operations on polygons will treat the polygons as
+ areas. Non-closed polygons will be treated as implicitly closed.
+*/
+
+QPolygon QPolygon::intersected(const QPolygon &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+
+ return subject.intersected(clip).toFillPolygon().toPolygon();
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is \a r subtracted from this polygon.
+
+ Set operations on polygons will treat the polygons as
+ areas. Non-closed polygons will be treated as implicitly closed.
+
+*/
+
+QPolygon QPolygon::subtracted(const QPolygon &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+
+ return subject.subtracted(clip).toFillPolygon().toPolygon();
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is the union of this polygon and \a r.
+
+ Set operations on polygons will treat the polygons as
+ areas. Non-closed polygons will be treated as implicitly closed.
+
+ \sa intersected(), subtracted()
+*/
+
+QPolygonF QPolygonF::united(const QPolygonF &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+
+ return subject.united(clip).toFillPolygon();
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is the intersection of this polygon and \a r.
+
+ Set operations on polygons will treat the polygons as
+ areas. Non-closed polygons will be treated as implicitly closed.
+
+*/
+
+QPolygonF QPolygonF::intersected(const QPolygonF &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+
+ return subject.intersected(clip).toFillPolygon();
+}
+
+/*!
+ \since 4.3
+
+ Returns a polygon which is \a r subtracted from this polygon.
+
+ Set operations on polygons will treat the polygons as
+ areas. Non-closed polygons will be treated as implicitly closed.
+
+*/
+
+QPolygonF QPolygonF::subtracted(const QPolygonF &r) const
+{
+ QPainterPath subject; subject.addPolygon(*this);
+ QPainterPath clip; clip.addPolygon(r);
+ return subject.subtracted(clip).toFillPolygon();
+}
+
+QT_END_NAMESPACE