Re: Reopen bug 535: Problem with highlit regions on Linux virtual terminal

[Alan Mackenzie]

Hi, David,

On Mon, Apr 06, 2009 at 04:35:59PM +0100, David De La Harpe Golden wrote:
> Alan Mackenzie wrote:

> These days, a lot text terminal emulators support 256 color mode.
> Unfortunately, the linux kernel console in particular doesn't seem to,
> but framebuffer (rather than hardware text mode) consoles on PC SVGA
> and similar hardware certianly *should* be able to in principle, it's
> possible just no-one's bothered writing the support.  Hmm.

> > And if font-locking is secondary, surely region highlighting is
> > tertiary?

> ? Stuff is still legible without font locking, you can't even
> see the region without region highlighting...

I've never had a problem seeing a region, and I've never used region
highlighting.  (OK, I know what you meant.).

> >No, not at all.  On the specific matter of the interaction between
> >region hilighting and font-locking/hi-locking, I raised a bug report
> >last summer, as requested by Stefan.  Until yesterday there had been
> >no discussion of it at all, as far as I am aware.

> I thought I posted something about the IMO nicest solution being to
> allow alphablending computation to mix the various foreground and
> background colors coming in from the overlaid faces somewhere around
> face realization time rather than just having higher priority override
> lower priority, but maybe I hallucinated actually saying that
> publically or thought I'd wait till I had a patch to do it.

No, I must just have forgotten about it, or missed it.  That sounds like
an excellent solution, so that you could make region highlighting do some
de-saturization, and adjust the degree of it to an optimum where the
colour change is slight enough not to be disturbing, yet firm enough to
be clearly seen.

> Such a solution still wouldn't work exactly amazingly on an 8-color 
> terminal to solve your "hi-lock background popping" problem, but would 
> on 256 color text terminal or bitmap gui emacs - i.e. the region face 
> could supply a translucent-looking tint instead of nuking the background 
> (and maybe foreground).

Yes.  

-- 
Alan Mackenzie (Nuremberg, Germany).