From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: E Sabof Newsgroups: gmane.emacs.bugs Subject: bug#18923: Alternative scrolling model Date: Sun, 02 Nov 2014 23:10:56 +0000 Message-ID: <87lhnt9p1b.fsf@gmail.com> References: <87wq7e9zcn.fsf@gmail.com> <87vbmy9wdx.fsf@gmail.com> <87sii1ahy9.fsf@gmail.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1414969946 32197 80.91.229.3 (2 Nov 2014 23:12:26 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 2 Nov 2014 23:12:26 +0000 (UTC) Cc: 18923@debbugs.gnu.org To: Stefan Monnier Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Mon Nov 03 00:12:19 2014 Return-path: Envelope-to: geb-bug-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 1Xl4Jl-0007QA-Gy for geb-bug-gnu-emacs@m.gmane.org; Mon, 03 Nov 2014 00:12:17 +0100 Original-Received: from localhost ([::1]:59628 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xl4Jl-00006d-3a for geb-bug-gnu-emacs@m.gmane.org; Sun, 02 Nov 2014 18:12:17 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:52279) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xl4Jc-00006L-7o for bug-gnu-emacs@gnu.org; Sun, 02 Nov 2014 18:12:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xl4JW-0005Ux-Ax for bug-gnu-emacs@gnu.org; Sun, 02 Nov 2014 18:12:08 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:49298) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xl4JW-0005Uq-6h for bug-gnu-emacs@gnu.org; Sun, 02 Nov 2014 18:12:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1Xl4JV-00038D-Q1 for bug-gnu-emacs@gnu.org; Sun, 02 Nov 2014 18:12:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: E Sabof Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 02 Nov 2014 23:12:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 18923 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: Original-Received: via spool by 18923-submit@debbugs.gnu.org id=B18923.141496986611965 (code B ref 18923); Sun, 02 Nov 2014 23:12:01 +0000 Original-Received: (at 18923) by debbugs.gnu.org; 2 Nov 2014 23:11:06 +0000 Original-Received: from localhost ([127.0.0.1]:46511 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Xl4Ib-00036u-Ma for submit@debbugs.gnu.org; Sun, 02 Nov 2014 18:11:06 -0500 Original-Received: from mail-wg0-f51.google.com ([74.125.82.51]:64352) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Xl4IZ-00036M-AX for 18923@debbugs.gnu.org; Sun, 02 Nov 2014 18:11:04 -0500 Original-Received: by mail-wg0-f51.google.com with SMTP id l18so9855369wgh.24 for <18923@debbugs.gnu.org>; Sun, 02 Nov 2014 15:10:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=references:from:to:cc:subject:in-reply-to:date:message-id :mime-version:content-type; bh=6txo3pvjKnJhyiZc1bgVrfywu1y837176vCwFj6FCl0=; b=wZRll8i97YB6Xk2pfg0JqRSc3jmmnYCEjLuaiToq6mIQWJM54Myr6NXaAE54ungOFx rWt2MG6PaP3yQMMXb2+eQ6Mn1nlKS1E41V6pEyXGqmzr3dArQ96AZ55WyB6Wmqc/JzfC 0gk6ynrMPhY6BAa1eZa+oiDdNE2ebEJCo6JbqBPFAzB+YIAnXGn5KIELXmMhBQ0ZMplZ eZ60z4X82NSNHiDXYOoQV5hWwFYJWy7/qnXnGVkD9cNfhwuVvm6UBdX5xsfXb1a3Qot4 4o3qwslFWiBxPpCUJMvxgMopTblK4USSbfV0QxR+Hz2TnB9CN6Xn555QiIKyLQjccXiu UT2A== X-Received: by 10.180.36.229 with SMTP id t5mr12135363wij.56.1414969857439; Sun, 02 Nov 2014 15:10:57 -0800 (PST) Original-Received: from ubuntu (173.103.115.87.dyn.plus.net. [87.115.103.173]) by mx.google.com with ESMTPSA id f9sm19902987wjw.31.2014.11.02.15.10.55 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Sun, 02 Nov 2014 15:10:56 -0800 (PST) In-reply-to: X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:95407 Stefan Monnier writes: >> The results should be identical to scroll-up/scroll-down, unless >> non-standard line heights are encountered. This means that a) the code would >> often be "under" such complications, not needing to know about them > > AFAIK scroll-margin is handled directly by the scroll-up/down code (tho > in a partly redundant way, but I believe it's because if we let the > subsequent redisplay do the job, it doesn't work quite right in all > cases). > >> It's a bit of a bug fix, but ultimately I have no objections. Perhaps it >> would be easier to estimate the breaking potential once it's "ready". > > OTOH to really get a lot of exposure, the best is to just install it > into Emacs as a replacement ;-) > >>> Have you measured the kind of impact it might have on performance? >>> Obviously, we could/should reimplement some of those functions in C. >> Right now it's slower, but tolerably so. > > There are already cases where Emacs scrolling is perceived as too slow. > AFAIK in most such cases the problem is due to the font-lock speed, > which should be unaffected by your code, but I still think actual > measurements quantifying the slowdown will be important. > > BTW, have you looked at the C code of scroll-up/down at all? > I'm not familiar with it, but it does do pixelwise scrolling to some > extent as well (tho IIUC only for really tall lines such as those with > images), so I'm curious to know exactly how the two compare. I have tried different settings, but they haven't quite worked for me. But I definitely need to become familiar with the existing implementation. Evgeni