As I said, this is old school. It is definitely a kunky, mechanical way of doing it.
I assume that Hans or DBear could figure out the JS.
The catch is that people want to click and drag. One can easily create a huge invisible object and make it draggable. I haven’t done that in this instance.
Attached is a simple 2-D example that can be used to control the operation of a window shutter by dragging or clicking.:
ShutterOperation.zip (3.0 MB)
Regarding the inverse motion of parallax, this can be done through nested containers with animating opposing relative positions of content. It can also be done to force objects to cross over when changing the width of the browser window.
Very basic manual parallax: DragParallax.hype.zip (14.3 KB)