Russian Qt Forum

void MyWidgetGL::paintEvent(QPaintEvent *)
{
    QPainter painter(this);
//    painter.setRenderHint(QPainter::HighQualityAntialiasing);
    painter.setRenderHint(QPainter::Antialiasing);
    parent->draw(&painter);
    painter.end();
}

main(){
    QGLFormat glf = QGLFormat::defaultFormat();
    glf.setSampleBuffers(false);
    glf.setSamples(8);
    QGLFormat::setDefaultFormat(glf);
}