From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: Luc Teirlinck Newsgroups: gmane.emacs.devel Subject: Re: Frame background mode Date: Tue, 28 Dec 2004 14:42:50 -0600 (CST) Message-ID: <200412282042.iBSKgoi8005021@manatee.dms.auburn.edu> References: <877jn4suf5.fsf@jurta.org> NNTP-Posting-Host: deer.gmane.org X-Trace: sea.gmane.org 1104266711 17764 80.91.229.6 (28 Dec 2004 20:45:11 GMT) X-Complaints-To: usenet@sea.gmane.org NNTP-Posting-Date: Tue, 28 Dec 2004 20:45:11 +0000 (UTC) Cc: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Dec 28 21:45:04 2004 Return-path: Original-Received: from lists.gnu.org ([199.232.76.165]) by deer.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 1CjODH-0006tj-00 for ; Tue, 28 Dec 2004 21:45:03 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CjOO9-0007vo-3S for ged-emacs-devel@m.gmane.org; Tue, 28 Dec 2004 15:56:17 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1CjONp-0007qr-26 for emacs-devel@gnu.org; Tue, 28 Dec 2004 15:55:57 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1CjONm-0007pY-Sb for emacs-devel@gnu.org; Tue, 28 Dec 2004 15:55:55 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1CjONm-0007pH-EH for emacs-devel@gnu.org; Tue, 28 Dec 2004 15:55:54 -0500 Original-Received: from [131.204.53.104] (helo=manatee.dms.auburn.edu) by monty-python.gnu.org with esmtp (Exim 4.34) id 1CjOB8-0000hQ-TW for emacs-devel@gnu.org; Tue, 28 Dec 2004 15:42:51 -0500 Original-Received: from manatee.dms.auburn.edu (localhost [127.0.0.1]) by manatee.dms.auburn.edu (8.12.10/8.12.10) with ESMTP id iBSKgoaB005024; Tue, 28 Dec 2004 14:42:50 -0600 (CST) Original-Received: (from teirllm@localhost) by manatee.dms.auburn.edu (8.12.10/8.12.10/Submit) id iBSKgoi8005021; Tue, 28 Dec 2004 14:42:50 -0600 (CST) X-Authentication-Warning: manatee.dms.auburn.edu: teirllm set sender to teirllm@dms.auburn.edu using -f Original-To: juri@jurta.org In-reply-to: <877jn4suf5.fsf@jurta.org> (message from Juri Linkov on Sun, 26 Dec 2004 21:52:54 +0200) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: main.gmane.org gmane.emacs.devel:31542 X-Report-Spam: http://spam.gmane.org/gmane.emacs.devel:31542 Juri Linkov wrote: I suggest to improve the formula used to determine whether the background is light or dark. The new formula uses the optimal weighting coefficients for RGB color components to reflect the perception of color luminance. and: + (>= (+ (* (nth 0 bg-color-values) 0.30) + (* (nth 1 bg-color-values) 0.59) + (* (nth 2 bg-color-values) 0.11)) Where did you get the .30 .59 .11 from? The way colors are perceived, including their brightness, depends on many things. Your monitor, your eyes, the background colors you are currently looking at (background color of your screen, color of your walls), the kind of light that is present other than the light produced by your computer (daylight, artificial light, the exact wavelength distribution of that artificial light, no additional light...), the intensity and angle of that light and so on. If you have an abnormal color vision, like me (I am a very abnormal trichromat) you have to customize your monitor. Customizing every single color for every single program you are using is hopeless. If I use the default settings of my monitor, the most basic color, white, 255 255 255, looks to me like light green with some shade of light blue, in other words, a greenish cyan. It probably looks perfectly white to most other people. (Actually, if I allow direct sunlight to hit my monitor, it turns white, even for me.) Green, 0 255 0 looks tremendously brighter than blue, 0 0 255, which in turn looks tremendously brighter than red, 255 0 0. I can _see_ red text on a black background, but not read it. Same with cyan on white, which is actually cyan on lighter and greener cyan. Same with yellow on white, which is actually light green on a more bluish light green. So I have to customize my monitor. The question is: what strategy do I need to use to customize it? What I did is I tried to make red, green and blue equally bright. Now, under my usual (day)light conditions, white looks white and I have less trouble with unreadability due to bad (for me) color combinations. If I allow direct sunlight to hit my monitor, then my de-cyanized white turns bright rose, but I better not allow that to happen anyway. Ideally, I would need different customizations of my monitor for day and night use, but the difference, while noticeable, is not really big enough to be worth that trouble. If I understand correctly the old code assumed that red, green and blue have exactly the same brightness. For my monitor, eye and usual conditions, that is actually correct, because I made it correct. Again, if I understood correctly, your code assumes that green is, to some specified degree, brighter than red, which is brighter than blue. Again, where did you get these numbers from? What brightness relation do people who construct monitors _try_ to achieve under which conditions? I agree with Eli that it is better not to mess with this until after the release. Sincerely, Luc.