From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Emacs, QT and Cairo Date: Wed, 14 Jul 2010 10:29:35 +0300 Message-ID: <83wrsyr068.fsf@gnu.org> References: <4C3CD120.4040905@swipnet.se> <5A91499A-0470-43FD-9F48-560CEAD3424C@mit.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: dough.gmane.org 1279092738 23942 80.91.229.12 (14 Jul 2010 07:32:18 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 14 Jul 2010 07:32:18 +0000 (UTC) Cc: jan.h.d@swipnet.se, emacs-devel@gnu.org To: Chad Brown Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Jul 14 09:32:17 2010 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OYwRz-0006Sd-Lj for ged-emacs-devel@m.gmane.org; Wed, 14 Jul 2010 09:32:15 +0200 Original-Received: from localhost ([127.0.0.1]:39830 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OYwRy-00029t-DA for ged-emacs-devel@m.gmane.org; Wed, 14 Jul 2010 03:32:14 -0400 Original-Received: from [140.186.70.92] (port=37882 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OYwRl-00028a-SG for emacs-devel@gnu.org; Wed, 14 Jul 2010 03:32:03 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OYwRk-00070s-Ab for emacs-devel@gnu.org; Wed, 14 Jul 2010 03:32:01 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]:59193) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OYwRk-00070j-4G for emacs-devel@gnu.org; Wed, 14 Jul 2010 03:32:00 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0L5J00A00E6GWP00@a-mtaout22.012.net.il> for emacs-devel@gnu.org; Wed, 14 Jul 2010 10:31:34 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.127.120.144]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0L5J0046SE8LDSF0@a-mtaout22.012.net.il>; Wed, 14 Jul 2010 10:31:34 +0300 (IDT) In-reply-to: <5A91499A-0470-43FD-9F48-560CEAD3424C@mit.edu> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) 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: news.gmane.org gmane.emacs.devel:127255 Archived-At: > From: Chad Brown > Date: Tue, 13 Jul 2010 15:30:49 -0700 > Cc: Emacs development discussions >=20 >=20 > On Jul 13, 2010, at 1:48 PM, Jan Dj=E4rv wrote: > > You would have to have a proper Cairo implementation of Emacs red= isplay before that can be useful. There was a patch for it here once= . >=20 > It would be interesting to see an analysis of emacs' redisplay need= s in light of modern cpu/gpu/network usage, or even a list of needs f= or emacs' redisplay priorities. I recall the 18->19->20 discussions = vaguely, but I'm willing to wager that there are far fewer people usi= ng x-terminals over 14.4k modem lines these days. :-) As Stephen wrote, the display optimizations are still relevant. We had at least 2 reminders of this lately: . Stefan's frustration with his nhexl mode, which somehow succeeds to bring the redisplay code to its knees, even on a local terminal. . Stefan's complaints about the slow-down related to the bidi reordering, when there are many frames simultaneously visible on the screen. > A `truly excellent' effort in this space would almost certainly req= uire a huge amount of work from at least one of the already generous/= overburdened developers who truly understands the redisplay internals= , and I would be surprised to hear that any such feels that they have= the free time to devote to such a blue-sky project. You are looking at the problem from the wrong angle. For such an effort to be worth our while, Someone(TM) should first present a plausible and convincing case for reimplementing the Emacs display engine. At the very least, there should be an analysis of the features we would like to have in Emacs, but cannot add without undul= y large effort, and which are available "for free" in Cairo or other display engines, or would be available "for free" in the suggested ne= w implementation of our own. And the number of these features should b= e large enough to provide a "critical mass" sufficient to make the redesign decision. Then, and only then, the next step would be to look for volunteers to do the job. > I do wonder if anyone has concrete suggestions for a starting point= for some of us `younger' people, though. The starting point is, of course, a thorough study of the current display engine.