Detect if item is REALLY visible

If an element can be seen by a person, EVERYTHING must be true:

• jQuery(elem).is(':visible')returns true. In jQuery 1.3.2+, an element is displayed if its reported offset width or offsetHeight specified by the browser is greater than 0 .
• visibilitystyle is not hidden.
• opacitystyle is not 0.

However, they do not cover all cases. For example, one simple case that I can think of is that if an element extends beyond the visible area of ​​its ancestors and that the ancestor has a style overflow: hidden, then the element cannot be seen.

Any existing examples / jQuery plugins, etc. which cover most (if not all) of the possibilities?