From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Issues with partial repainting when enabling cairo Date: Fri, 27 Jan 2017 18:51:40 +0200 Message-ID: <831svo1m5f.fsf@gnu.org> References: <87bmus8scp.fsf@wavexx.thregr.org> <834m0k1poc.fsf@gnu.org> <871svoe9u2.fsf@wavexx.thregr.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1485536059 4002 195.159.176.226 (27 Jan 2017 16:54:19 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 27 Jan 2017 16:54:19 +0000 (UTC) Cc: emacs-devel@gnu.org To: Yuri D'Elia Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Jan 27 17:54:15 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cX9mt-0000Sx-PR for ged-emacs-devel@m.gmane.org; Fri, 27 Jan 2017 17:54:11 +0100 Original-Received: from localhost ([::1]:46781 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX9mz-0002ma-0Z for ged-emacs-devel@m.gmane.org; Fri, 27 Jan 2017 11:54:17 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50432) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX9kl-0001If-LL for emacs-devel@gnu.org; Fri, 27 Jan 2017 11:52:00 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cX9kh-0006cg-Lf for emacs-devel@gnu.org; Fri, 27 Jan 2017 11:51:59 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:49238) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cX9kh-0006ca-It; Fri, 27 Jan 2017 11:51:55 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:4387 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1cX9kg-0007OY-Ft; Fri, 27 Jan 2017 11:51:55 -0500 In-reply-to: <871svoe9u2.fsf@wavexx.thregr.org> (message from Yuri D'Elia on Fri, 27 Jan 2017 17:39:17 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:211647 Archived-At: > From: Yuri D'Elia > Date: Fri, 27 Jan 2017 17:39:17 +0100 > > On Fri, Jan 27 2017, Eli Zaretskii wrote: > >> There are some bug reports about cairo on the bts, but nothing so > >> glaring. > > > > Glaring display bugs are the main problem with Cairo, AFAIK. We need > > motivated individuals who'd work on debugging and fixing those > > problems. > > Apart from being newer, is there any advantage that cairo should bring > to the display engine? It's supposed to be the future of GUI desktop on Unix, beyond Xlib interface and the traditional X server-client setup, so I think it's important for us to move in that direction. > When I was reading the display code (for debugging the line truncation > hang some months ago) it didn't seem quickly approachable to the > uninitiated. In addition, there's quite some historical baggage one > needs to consider. You are talking about xdisp.c, which is entirely irrelevant to Cairo. The Cairo-related code is in xterm.c and xfns.c (and also in ftcrfont.c (the "font driver") and in image.c, but those are most probably unrelated to what you see). > Each time I read the internals I can get further, but I've been using > emacs for 10+ years, and I wonder what kind of guru one needs to be to > have the balls^H^H^H^Hbeard to fix cairo ;) The trick is to investigate specific problems without trying to understand the entire big picture. I'm quite sure the basic design of the Cairo support is sound, the bugs are in minor details. Let me know if you need some guidance in finding the places where the scroll-related problems you saw could hide. TIA