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 21:19:57 +0300 Message-ID: <83y2qqf29e.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> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="127557"; mail-complaints-to="usenet@ciao.gmane.io" Cc: rms@gnu.org, emacs-devel@gnu.org, rudalics@gmx.at, rrandresf@gmail.com, dgutov@yandex.ru, acm@muc.de To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Apr 20 20:20:58 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 1jQb2O-000X1W-PM for ged-emacs-devel@m.gmane-mx.org; Mon, 20 Apr 2020 20:20:56 +0200 Original-Received: from localhost ([::1]:40396 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQb2N-00024M-QS for ged-emacs-devel@m.gmane-mx.org; Mon, 20 Apr 2020 14:20:55 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:41406 helo=eggs1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQb1k-0001Py-6p for emacs-devel@gnu.org; Mon, 20 Apr 2020 14:20:16 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:52699) by eggs1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jQb1i-0003Ti-Id; Mon, 20 Apr 2020 14:20:14 -0400 Original-Received: from [176.228.60.248] (port=4940 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jQb1Z-0008Ch-W7; Mon, 20 Apr 2020 14:20:06 -0400 In-Reply-To: (message from Stefan Monnier on Mon, 20 Apr 2020 13:47:10 -0400) 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:247411 Archived-At: > From: Stefan Monnier > Cc: Dmitry Gutov , acm@muc.de, rrandresf@gmail.com, > emacs-devel@gnu.org, rms@gnu.org, rudalics@gmx.at > Date: Mon, 20 Apr 2020 13:47:10 -0400 > > If you do `C-n C-n C-n` quickly, the redisplay between the second and > the third might very well be skipped, OTOH (since the second and third > `C-n` might arrive while we're processing the first, in which case > `input_was_pending` will be true when processing the second). 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.