void GLWidget::mouseMoveEvent(QMouseEvent *event)
{
    /*
    int dx = event->x() - m_lastPos.x();
    int dy = event->y() - m_lastPos.y();
    */
    int dx = event->x() - width()/2;
    int dy = event->y() - height()/2;

    float phi = atan2(m_player.direction.z(), m_player.direction.x());
    float theta = acos(m_player.direction.y());

    phi = phi + dx * 0.005;
    theta = theta + dy * 0.005;

    if(theta < 0.01) theta = 0.01;
    if(theta > 3.14) theta = 3.14;

    m_player.direction.setX(sin(theta) * cos(phi));
    m_player.direction.setY(cos(theta));
    m_player.direction.setZ(sin(theta) * sin(phi));

    /*
    if (event->buttons() & Qt::LeftButton) {
        setXRotation(m_camXRot + 0.5f * dy);
        setYRotation(m_camYRot + 0.5f * dx);
    } else if (event->buttons() & Qt::RightButton) {
        setXRotation(m_camXRot + 0.5f * dy);
        setZRotation(m_camZRot + 0.5f * dx);
    }
    m_lastPos = event->pos();
    */
}