From: Eli Zaretskii <eliz@gnu.org>
To: "Stephen J. Turnbull" <stephen@xemacs.org>
Cc: aaditya@sood.net.in, emacs-devel@gnu.org
Subject: Re: alpha support for colors
Date: Wed, 31 Oct 2012 06:00:07 +0200 [thread overview]
Message-ID: <83ip9r70l4.fsf@gnu.org> (raw)
In-Reply-To: <87lienjsz0.fsf@uwakimon.sk.tsukuba.ac.jp>
> From: "Stephen J. Turnbull" <stephen@xemacs.org>
> Cc: aaditya sood <aaditya@sood.net.in>,
> emacs-devel@gnu.org
> Date: Wed, 31 Oct 2012 11:06:11 +0900
>
> Eli Zaretskii writes:
>
> > What do you mean by "composition of all the faces"? Why "all"?
>
> I suspect aaditya is thinking in terms of bitmap composition
> operations on graphics layers, not Emacs faces.
Maybe. I just don't understand clearly enough what exactly was the
intent.
As you know, Emacs doesn't operate on the bitmap level, except very
low in the terminal-specific code. At that level, there are no faces
anymore, just colors and other graphics-related stuff.
> So he'd like to put an overlay on some text, give that overlay a 'face
> property of '(+ red), and turn all the blue text in the overlay to
> violet (the RGB sum of #F00 and #00F == #F0F).
Maybe I don't get something, but (a) this _is_ about faces and their
combination, '(+ red) being a kind of "syntactic sugar"; and (b) all
it needs is the ability to combine colors when merging faces, instead
of just selecting one color of the two. By contrast, alpha-blending,
AFAIU, is about transparency, not about combining any 2 colors. So
I'm probably still missing something.
next prev parent reply other threads:[~2012-10-31 4:00 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-29 20:19 alpha support for colors aaditya sood
2012-10-30 1:52 ` Chong Yidong
2012-10-30 5:02 ` aaditya sood
2012-10-30 5:07 ` Masatake YAMATO
2012-10-30 6:51 ` joakim
2012-10-30 7:37 ` aaditya sood
2012-10-30 13:28 ` Stefan Monnier
2012-10-30 17:45 ` Eli Zaretskii
2012-10-31 2:06 ` Stephen J. Turnbull
2012-10-31 4:00 ` Eli Zaretskii [this message]
2012-10-30 17:43 ` Eli Zaretskii
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=83ip9r70l4.fsf@gnu.org \
--to=eliz@gnu.org \
--cc=aaditya@sood.net.in \
--cc=emacs-devel@gnu.org \
--cc=stephen@xemacs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).