From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Scrolling commands and skipping redisplay, was: Re: emacs rendering comparisson between emacs23 and emacs26.3 Date: Mon, 20 Apr 2020 21:52:05 +0300 Message-ID: <83wo6af0ru.fsf@gnu.org> References: <20200403174757.GA8266@ACM> <83eesvmj15.fsf@gnu.org> <6eec7f68-770e-b3b1-4627-6222f3ef7216@yandex.ru> <83ftd9kwlu.fsf@gnu.org> <1de9d24f-eeb7-7d0a-3768-4baba4365066@yandex.ru> <83zhbcdmyi.fsf@gnu.org> <61f565cd-4fee-d48c-a9ef-b78419b3d058@yandex.ru> <83wo6ed4kb.fsf@gnu.org> <464b5639-7790-fdbc-b519-22a6b0e8c016@yandex.ru> <83o8rqaucp.fsf@gnu.org> <551c7634-f614-c5a7-c089-33a0dc56574d@yandex.ru> <83imhyaqyw.fsf@gnu.org> <3ddcec07-079f-18e8-81a7-76eaf9a8187a@yandex.ru> <83d083ia16.fsf@gnu.org> <83y2qqgrr6.fsf@gnu.org> <837dyagkwm.fsf@gnu.org> <532544ab-55ec-aab9-1c2f-fa0081332401@yandex.ru> <834ktegivn.fsf@gnu.org> <83y2qqf29e.fsf@gnu.org> <66c68958-ca7d-7353-2ca6-d8476444965a@yandex.ru> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="8841"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rms@gnu.org, emacs-devel@gnu.org, rudalics@gmx.at, rrandresf@gmail.com, monnier@iro.umontreal.ca, acm@muc.de To: Dmitry Gutov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Apr 20 20:53:15 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jQbXe-0002BY-Sk for ged-emacs-devel@m.gmane-mx.org; Mon, 20 Apr 2020 20:53:14 +0200 Original-Received: from localhost ([::1]:40866 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQbXd-0006CM-VK for ged-emacs-devel@m.gmane-mx.org; Mon, 20 Apr 2020 14:53:13 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:47816 helo=eggs1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQbWt-0005Ur-PL for emacs-devel@gnu.org; Mon, 20 Apr 2020 14:52:28 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:53118) by eggs1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQbWs-0003sV-9F; Mon, 20 Apr 2020 14:52:26 -0400 Original-Received: from [176.228.60.248] (port=2905 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jQbWg-0004Ho-GY; Mon, 20 Apr 2020 14:52:15 -0400 In-Reply-To: <66c68958-ca7d-7353-2ca6-d8476444965a@yandex.ru> (message from Dmitry Gutov on Mon, 20 Apr 2020 21:29:07 +0300) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:247416 Archived-At: > Cc: acm@muc.de, rrandresf@gmail.com, emacs-devel@gnu.org, rms@gnu.org, > rudalics@gmx.at > From: Dmitry Gutov > Date: Mon, 20 Apr 2020 21:29:07 +0300 > > On 20.04.2020 21:19, Eli Zaretskii wrote: > > Btw, "line" in this context is actually the amount of pixels equal to > > the canonical line height, not a physical line. When the display > > engine counts "lines" for the purpose of comparison with the value of > > scroll-conservatively, it actually counts pixels and then divides that > > by the canonical line height, it doesn't count screen lines. So if > > some lines in the buffer are displayed taller than the default face, > > you will see a lot of recentering regardless of what you do. > > I wonder if this was a result of some feature request. No. Scrolling-related variables always worked this way, since Emacs 21. You will see the same with scroll-margin, for example. > Sounds unnecessarily complex, IMHO. If you think about this for a while, you will realize that it's the only sane way of doing that, in an editor that is required to handle lines which can contain anything: small and large characters, images, you name it. Any other way, and you will have a myriad of special conditions and complex decisions.