From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Yuri Khan Newsgroups: gmane.emacs.help Subject: Re: Is it possible to scroll smoothly in Emacs? Date: Fri, 5 Dec 2014 23:15:37 +0700 Message-ID: References: <86tx1codxj.fsf@mailinator.com> <87vblrpm57.fsf@newcastle.ac.uk> <877fy7azys.fsf@wmi.amu.edu.pl> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1417796167 11429 80.91.229.3 (5 Dec 2014 16:16:07 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 5 Dec 2014 16:16:07 +0000 (UTC) Cc: "help-gnu-emacs@gnu.org" To: "J. David Boyd" Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Dec 05 17:16:01 2014 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XwvY0-0007Vk-JM for geh-help-gnu-emacs@m.gmane.org; Fri, 05 Dec 2014 17:16:00 +0100 Original-Received: from localhost ([::1]:51239 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwvY0-00065U-5m for geh-help-gnu-emacs@m.gmane.org; Fri, 05 Dec 2014 11:16:00 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:48118) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwvXg-000658-Ns for help-gnu-emacs@gnu.org; Fri, 05 Dec 2014 11:15:41 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XwvXf-0003D4-JA for help-gnu-emacs@gnu.org; Fri, 05 Dec 2014 11:15:40 -0500 Original-Received: from mail-ig0-x231.google.com ([2607:f8b0:4001:c05::231]:38119) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XwvXf-0003B6-A2 for help-gnu-emacs@gnu.org; Fri, 05 Dec 2014 11:15:39 -0500 Original-Received: by mail-ig0-f177.google.com with SMTP id z20so967168igj.10 for ; Fri, 05 Dec 2014 08:15:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=c3/iQ3MTAZS3vwVYA9A9wSwvJni7uiHDDeLDUrRPkmQ=; b=gHTE8/BTnxyfSKeMxRyVPhcNIBAECpLxtDLOvOM2erkVKFbEU/+cAdXr2qvnNRsJ2t PlvzQPkKwnsu8bUWt+v6UuzfMAiA/WHn89n0+ThcqqyU2dFv2sLXe8mW+rM/I3JjoORG OhE8h7A7LQESBx1bLrSBW/n5KKjUJBX6+iaRI4e/7TbzRGXseK1+V96Mu14ogz+Luv8I WEnbHK7l83XBXikjlXpgWe6kc+5cQ4tsnDYsihg+bYlgI+XCo/TTBAMQ8SjaKQm+Y9Vf 5x3wKZPxQJJjGw0Kzz5/GUepHY+CnpelGPlKppauZGSIaz4yd3Znql50rcbcyJX99c00 6chA== X-Received: by 10.107.15.226 with SMTP id 95mr15977273iop.12.1417796137096; Fri, 05 Dec 2014 08:15:37 -0800 (PST) Original-Received: by 10.107.48.82 with HTTP; Fri, 5 Dec 2014 08:15:37 -0800 (PST) In-Reply-To: X-Google-Sender-Auth: n_PlXtILrHjXa2PVZFGZWpjHE3w X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:4001:c05::231 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:101423 Archived-At: On Fri, Dec 5, 2014 at 8:52 PM, J. David Boyd wrote: > I don't think I understand. My emacs seems to scroll fairly smoothly to me. > What exactly are we talking about when we say 'smooth scroll'? Basically, the antithesis of doing whatever possible to ensure acceptable performance when editing over a slow link. In short: using non-integer line offsets (down to single pixels if performance allows); remaining responsive during the scroll; and ending the scroll with a deceleration such that the first two derivatives of the scroll offset are zero at the end and the third derivative stays continuous throughout. (Optionally, pressing Page Down might also accelerate from 0 to the scroll speed according to the same profile.)