From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Ligatures (was: Unify the Platforms: Cairo+FreeType+Harfbuzz Everywhere (except TTY)) Date: Fri, 22 May 2020 09:12:22 +0300 Message-ID: <83wo544hx5.fsf@gnu.org> References: <20200517165953.000044d2@web.de> <83lflqblp0.fsf@gnu.org> <83ftbybio3.fsf@gnu.org> <83zha69xs2.fsf@gnu.org> <83367x9qeq.fsf@gnu.org> <0ccae2a4-533b-d15c-2884-c2f00b067776@gmail.com> <83wo5987mk.fsf@gnu.org> <99d4beed-88ae-b5cd-3ecb-a44325c8a1dc@gmail.com> <20200518215908.GA57594@breton.holly.idiocy.org> <83mu6481v3.fsf@gnu.org> <75a90563-51b4-d3b8-4832-fc0e2542af0d@gmail.com> <83blmi7hys.fsf@gnu.org> <837dx55qff.fsf@gnu.org> <834ks95cmz.fsf@gnu.org> <4faa291f-f2df-36d1-73d5-332b93a9b6d8@gmail.com> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="53052"; mail-complaints-to="usenet@ciao.gmane.io" Cc: cpitclaudel@gmail.com, alan@idiocy.org, emacs-devel@gnu.org To: Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Fri May 22 08:12:53 2020 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jc0vN-000DiA-5P for ged-emacs-devel@m.gmane-mx.org; Fri, 22 May 2020 08:12:53 +0200 Original-Received: from localhost ([::1]:37878 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jc0vM-0002iH-6P for ged-emacs-devel@m.gmane-mx.org; Fri, 22 May 2020 02:12:52 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:35790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jc0ut-0002H2-8p for emacs-devel@gnu.org; Fri, 22 May 2020 02:12:23 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:58709) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jc0ur-0003En-JZ; Fri, 22 May 2020 02:12:21 -0400 Original-Received: from [176.228.60.248] (port=2559 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jc0uq-0003f8-Og; Fri, 22 May 2020 02:12:21 -0400 In-Reply-To: (message from Pip Cet on Thu, 21 May 2020 21:16:44 +0000) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:251198 Archived-At: > From: Pip Cet > Date: Thu, 21 May 2020 21:16:44 +0000 > Cc: Eli Zaretskii , alan@idiocy.org, emacs-devel@gnu.org > > (set-char-table-range composition-function-table t '([".+" 0 > font-shape-gstring])) > > should work, but it has weird side effects that I'm pretty sure aren't > intended (paren highlighting is broken, for example). This is not the right way. The right way is to do the likes of the following: (set-char-table-range composition-function-table '(?f . ?f) (list (vector "ffi" 0 'compose-gstring-for-graphic))) This shows how to do this only for the "ffi" ligature, but I think it makes the idea clear. Tassilo posted here some code ho wrote that supports more (and different) ligatures which are supposed to be used like prettify-symbols-mode. The idea is to populate composition-function-table only for characters that should trigger ligation. Whether to use compose-gstring-for-graphic or font-shape-gstring depends on what you want to happen when the font doesn't have a glyph for a certain ligature: the latter will then cause the characters be displayed as usual, as separate characters, the latter will display them as a single display element, a kind of "fake ligature".