Re: new frame-parameter "alpha"

[David De La Harpe Golden]

Seiji Zenitani wrote:

> 
> You are talking about Emacs.app, a coming Cocoa port.  I confirmed that
> Emacs.app comes with the background color alpha [e.g.
> (set-background-color "ARGBccffffff") ].
> 

Hmm. That's interesting. How general is it? :

Possibly an actually useful use for alpha blending would be "emacs
internal" alpha blending of overlapping overlay/text-properties
backgrounds+foregrounds* (rather than just the current priority-based
overriding).

Does emacs.app do that too, or is it only a hack affecting
the frame background?

* So that e.g. hi-lock faces could subtly "show through" a region
highlight on top of them, or whatever, addressing someone's
slightly over-the-top on-list complaint from a few weeks back.