Math challenge with Scroller ... anyone?

Hi,

I’m challenged to do a scrollbar like explained in the image. It has to center the ‘current’ thumbnail and scale it up when under the center line of the containerclip. Scale the surrounding thumbnails down when off the centerline, and fade them out as they get closer to either edge (left or right).

How would you go about doing the math to achieve this? I’ve viewed Lee Brimelow’s tutorials on oop scroolbar, but can’t seem to get this exact behavior.