qpolygon.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qpolygon.h"
#include "qrect.h"
#include "qdatastream.h"
#include "qdebug.h"
#include "qpainterpath.h"
#include "qtransform.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;
        }
    }
}
 
/*****************************************************************************
  QPolygon member functions
 *****************************************************************************/
 
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());
}
 
QPolygon::QPolygon(int nPoints, const int *points)
{
    setPoints(nPoints, points);
}
 
void QPolygon::translate(int dx, int dy)
{
    if (dx == 0 && dy == 0)
        return;
 
    QPoint *p = data();
    int i = size();
    QPoint pt(dx, dy);
    while (i--) {
        *p += pt;
        ++p;
    }
}
 
QPolygon QPolygon::translated(int dx, int dy) const
{
    QPolygon copy(*this);
    copy.translate(dx, dy);
    return copy;
}
 
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();
}
 
void QPolygon::setPoint(int index, int x, int y)
{
    (*this)[index] = QPoint(x, y);
}
 
 
void QPolygon::setPoints(int nPoints, const int *points)
{
    resize(nPoints);
    int i = 0;
    while (nPoints--) {
        setPoint(i++, *points, *(points+1));
        points += 2;
    }
}
 
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);
}
 
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;
    }
}
 
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);
}
 
 
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;
    }
}
 
 
QRect QPolygon::boundingRect() const
{
    const QPoint *pd = constData();
    const QPoint *pe = pd + size();
    if (pd == pe)
        return QRect(0, 0, 0, 0);
    int minx, maxx, miny, maxy;
    minx = maxx = pd->x();
    miny = maxy = pd->y();
    ++pd;
    for (; pd != pe; ++pd) {
        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();
    }
    return QRect(QPoint(minx,miny), QPoint(maxx,maxy));
}
 
#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QPolygon &a)
{
    QDebugStateSaver saver(dbg);
    dbg.nospace() << "QPolygon(";
    for (int i = 0; i < a.size(); ++i)
        dbg.nospace() << a.at(i);
    dbg.nospace() << ')';
    return dbg;
}
#endif
 
 
/*****************************************************************************
  QPolygonF member functions
 *****************************************************************************/
 
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()));
}
 
QPolygonF::QPolygonF(const QPolygon &a)
{
    reserve(a.size());
    for (int i=0; i<a.size(); ++i)
        append(a.at(i));
}
 
void QPolygonF::translate(const QPointF &offset)
{
    if (offset.isNull())
        return;
 
    QPointF *p = data();
    int i = size();
    while (i--) {
        *p += offset;
        ++p;
    }
}
 
QPolygonF QPolygonF::translated(const QPointF &offset) const
{
    QPolygonF copy(*this);
    copy.translate(offset);
    return copy;
}
 
QRectF QPolygonF::boundingRect() const
{
    const QPointF *pd = constData();
    const QPointF *pe = pd + size();
    if (pd == pe)
        return QRectF(0, 0, 0, 0);
    qreal minx, maxx, miny, maxy;
    minx = maxx = pd->x();
    miny = maxy = pd->y();
    ++pd;
    while (pd != pe) {
        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);
}
 
QPolygon QPolygonF::toPolygon() const
{
    QPolygon a;
    a.reserve(size());
    for (int i=0; i<size(); ++i)
        a.append(at(i).toPoint());
    return a;
}
 
QPolygon::operator QVariant() const
{
    return QVariant::fromValue(*this);
}
 
/*****************************************************************************
  QPolygon stream functions
 *****************************************************************************/
#ifndef QT_NO_DATASTREAM
QDataStream &operator<<(QDataStream &s, const QPolygon &a)
{
    const QList<QPoint> &v = a;
    return s << v;
}
 
QDataStream &operator>>(QDataStream &s, QPolygon &a)
{
    QList<QPoint> &v = a;
    return s >> v;
}
#endif // QT_NO_DATASTREAM
 
/*****************************************************************************
  QPolygonF stream functions
 *****************************************************************************/
#ifndef QT_NO_DATASTREAM
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;
}
 
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)
{
    QDebugStateSaver saver(dbg);
    dbg.nospace() << "QPolygonF(";
    for (int i = 0; i < a.size(); ++i)
        dbg.nospace() << a.at(i);
    dbg.nospace() << ')';
    return dbg;
}
#endif
 
 
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));
}
 
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));
}
 
QPolygon QPolygon::united(const QPolygon &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
 
    return subject.united(clip).toFillPolygon().toPolygon();
}
 
QPolygon QPolygon::intersected(const QPolygon &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
 
    return subject.intersected(clip).toFillPolygon().toPolygon();
}
 
QPolygon QPolygon::subtracted(const QPolygon &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
 
    return subject.subtracted(clip).toFillPolygon().toPolygon();
}
 
bool QPolygon::intersects(const QPolygon &p) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(p);
 
    return subject.intersects(clip);
}
 
QPolygonF QPolygonF::united(const QPolygonF &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
 
    return subject.united(clip).toFillPolygon();
}
 
QPolygonF QPolygonF::intersected(const QPolygonF &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
 
    return subject.intersected(clip).toFillPolygon();
}
 
QPolygonF QPolygonF::subtracted(const QPolygonF &r) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(r);
    return subject.subtracted(clip).toFillPolygon();
}
 
bool QPolygonF::intersects(const QPolygonF &p) const
{
    QPainterPath subject; subject.addPolygon(*this);
    QPainterPath clip; clip.addPolygon(p);
 
    return subject.intersects(clip);
}
 
QPolygonF::operator QVariant() const
{
    return QVariant::fromValue(*this);
}
 
QT_END_NAMESPACE