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Diffstat (limited to 'src/gui/painting/qpolygon.cpp')
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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 |