Time for action – moving the background

Now the question is how to move them at different speeds. The solution is quite simple: the slowest one, the sky, is the smallest image. The fastest background, the ground and the grass, are the largest images. Now when we have a look at the end of the movePlayer() function's slot we see this:

qreal ff = qMin(1.0, m_skippedMoving/(m_fieldWidth - width()));
m_sky->setPos(-(m_sky->boundingRect().width() - width()) * ff, 0);
m_grass->setPos(-(m_grass->boundingRect().width() - width()) * ff, m_grass->y());
m_trees->setPos(-(m_trees->boundingRect().width() - width()) * ff, m_trees->y());
m_ground->setPos(-(m_ground->boundingRect().width() - width()) * ff, m_ground->y());

What just happened?

What are we doing here? At the beginning, the sky's left border is the same as the view's left border, both at point (0, 0). At the end, when Benjamin has walked to the maximum right, the sky's right border should be the same as the view...