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: Pixel-based display functions Date: Wed, 28 Jan 2015 17:33:33 +0200 Message-ID: <83oapior76.fsf@gnu.org> References: <87k31fwwyv.fsf@ferrier.me.uk> <87bnmq9ibf.fsf@ferrier.me.uk> <87lhlrx5fc.fsf@building.gnus.org> <878uhrcr5l.fsf@building.gnus.org> <83sifzjflk.fsf@gnu.org> <87fvbyagaw.fsf@building.gnus.org> <83iogujvbq.fsf@gnu.org> <87tx0ee7rf.fsf@building.gnus.org> <83egricpvg.fsf@gnu.org> <87zj97vic8.fsf@building.gnus.org> <83wq4argjp.fsf@gnu.org> <87iofui8vo.fsf@building.gnus.org> <838ugqqczp.fsf@gnu.org> <877fw9dndz.fsf@building.gnus.org> <83a914ozsh.fsf@gnu.org> <874mrb1t62.fsf_-_@building.gnus.org> <87h9vbfk81.fsf@zigzag.favinet> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: ger.gmane.org 1422459250 14115 80.91.229.3 (28 Jan 2015 15:34:10 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 28 Jan 2015 15:34:10 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Jan 28 16:34:10 2015 Return-path: Envelope-to: ged-emacs-devel@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 1YGUd4-00032C-N2 for ged-emacs-devel@m.gmane.org; Wed, 28 Jan 2015 16:34:06 +0100 Original-Received: from localhost ([::1]:54219 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGUd4-0006YD-7L for ged-emacs-devel@m.gmane.org; Wed, 28 Jan 2015 10:34:06 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:36843) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGUcl-0006Y7-TA for emacs-devel@gnu.org; Wed, 28 Jan 2015 10:33:51 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YGUcg-0004LN-L0 for emacs-devel@gnu.org; Wed, 28 Jan 2015 10:33:47 -0500 Original-Received: from mtaout25.012.net.il ([80.179.55.181]:54183) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YGUcg-0004LB-DA for emacs-devel@gnu.org; Wed, 28 Jan 2015 10:33:42 -0500 Original-Received: from conversion-daemon.mtaout25.012.net.il by mtaout25.012.net.il (HyperSendmail v2007.08) id <0NIW00F0086EBE00@mtaout25.012.net.il> for emacs-devel@gnu.org; Wed, 28 Jan 2015 17:28:51 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by mtaout25.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0NIW006AI8C38390@mtaout25.012.net.il> for emacs-devel@gnu.org; Wed, 28 Jan 2015 17:28:51 +0200 (IST) In-reply-to: <87h9vbfk81.fsf@zigzag.favinet> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 80.179.55.181 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:181914 Archived-At: > From: Thien-Thi Nguyen > Date: Wed, 28 Jan 2015 08:16:46 +0100 >=20 > 1) A pixel equivalent of `current-column' As I wrote elsewhere, these already exist. > See also mid-2002 thread "column->int float diff". > Gist: rms suggests using (C language) =E2=80=98iterator=E2=80=99. Indeed. So I think the "float column" approach is not TRT, and we should instead work in pixels. That is also how the 'iterator' objec= t works, so this will naturally plug into the existing infrastructure. Using a float column solves only half of the problem. The other half= , how to convert such a column into the actual screen position, is stil= l there. The indentation code should use the '(space . (PIXELS))' value of display property to align text on pixel-granular boundary, instead of inserting TABs and spaces. This already works, so does not need any changes on the C level. We do need to teach the display engine how to fill and/or justify tex= t with pixel granularity. But that's a separate isue. I asked for someone to show a list of tasks included in this, and no one did. I think different people have different ideas about what needs to be done and how, and also about what's already available. S= o preparing such an agreed-upon list is IMO necessary for any constructive discussions and advances.