void FreeRegionGrabber::grabRect()
{
QPolygon pol = selection;
if ( !pol.isEmpty() )
{
grabbing = true;
int xOffset = pixmap.rect().x() - pol.boundingRect().x();
int yOffset = pixmap.rect().y() - pol.boundingRect().y();
QPolygon translatedPol = pol.translated(xOffset, yOffset);
QPixmap pixmap2(pol.boundingRect().size());
pixmap2.fill(Qt::transparent);
QPainter pt;
pt.begin(&pixmap2);
if (pt.paintEngine()->hasFeature(QPaintEngine::PorterDuff)) {
pt.setRenderHints(QPainter::Antialiasing | QPainter::HighQualityAntialiasing | QPainter::SmoothPixmapTransform, true);
pt.setBrush(Qt::black);
pt.setPen(QPen(QBrush(Qt::black), 0.5));
pt.drawPolygon(translatedPol);
pt.setCompositionMode(QPainter::CompositionMode_SourceIn);
} else {
pt.setClipRegion(QRegion(translatedPol));
pt.setCompositionMode(QPainter::CompositionMode_Source);
}
pt.drawPixmap(pixmap2.rect(), pixmap, pol.boundingRect());
pt.end();
emit freeRegionUpdated(pol);
emit freeRegionGrabbed(pixmap2);
}
}
void paintEvent( QPaintEvent* pe ) override
{
Q_UNUSED( pe );
QPainter p;
p.begin( this );
p.setPen( Qt::red );
QPolygonF t = mPoly.translated( -mPoly.boundingRect().left(), -mPoly.boundingRect().top() );
p.drawConvexPolygon( t );
p.end();
}