From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: =?UTF-8?Q?Cl=c3=a9ment_Pit-Claudel?= Newsgroups: gmane.emacs.devel Subject: Re: Ligatures (was: Unify the Platforms: Cairo+FreeType+Harfbuzz Everywhere (except TTY)) Date: Thu, 21 May 2020 16:51:47 -0400 Message-ID: <4faa291f-f2df-36d1-73d5-332b93a9b6d8@gmail.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="130273"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 Cc: alan@idiocy.org, emacs-devel@gnu.org To: Eli Zaretskii , Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu May 21 22:52:25 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 1jbsAy-000Xlw-Q7 for ged-emacs-devel@m.gmane-mx.org; Thu, 21 May 2020 22:52:24 +0200 Original-Received: from localhost ([::1]:40610 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jbsAx-0002Kv-Sc for ged-emacs-devel@m.gmane-mx.org; Thu, 21 May 2020 16:52:23 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:48090) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jbsAS-0001v6-DV for emacs-devel@gnu.org; Thu, 21 May 2020 16:51:52 -0400 Original-Received: from mail-qv1-xf2c.google.com ([2607:f8b0:4864:20::f2c]:34336) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jbsAR-0001hO-H2; Thu, 21 May 2020 16:51:52 -0400 Original-Received: by mail-qv1-xf2c.google.com with SMTP id r3so3771204qve.1; Thu, 21 May 2020 13:51:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ukLyr6aqM1P8EMlMSGhi7NJPplt8XuIz+F0cSrJkRjI=; b=SnlRE6Cm/7YjND/9KhydOlHD/yREx5icZRmXheqIY3SRGzOY4hAmMEiJBxyjK0vhm4 aqayPd7IycZVQMNEJhV9UI6adrCYtUb0B/FPAqeuSXKVZa9h/yimjHz7z5vkuJwGAo+5 l/QbfMf8Zdi91UokC5sgzEzI4hwusKcZDd7mkzzc6e/TEz4pcD6tsMQoKevIHsdQ76PC BpU2Rnov+VzpjLHVGBQxX7pHTm5sAqIW1fVG+E+5/YbhCocE7OQQphKlKshtOhWlcpOM kusuowBcWxpi9ovquVznHPxWXOi8wYsfQ4uJV0/IiuuLICnfpqxTUepzc5xdVyW/iNDO euDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ukLyr6aqM1P8EMlMSGhi7NJPplt8XuIz+F0cSrJkRjI=; b=NyrMYjYUGQiqiNAU5mYqgaNsoK4P2S+VcGG0OkIJpqLkOcijNNIme1P0fbm5aTKd78 bVqIR4I88pJvTyar/dJpG95m+OcyC5iEo+hSMOIzyf1DWGoNBWjGJOvBKysAFAlm1+0/ wFjmEtE+V0TmaW38GuXfEFZqRSGTFyAgCIX570UAUEdQfX6TDimG7Ud91la48+EfbxKU Gm1/2Y5vyd0X474Vceoi7rsTX7NIXqqXnes5a5ayBN3FlaMhVgm9Aic674rT+BbiAI0H J2sMXnbuxFSjHf3ALWgDCbK738sNzUHYd1ot5PI42LzrEZKoesqVZEgPljgoIgVeSaei ctFQ== X-Gm-Message-State: AOAM532bNRdMQ6/ykTnBIG/cdhT9kEdjTrV8mjZgkGZueyB3d3r1+7pZ aaCTqLttHkkelT0SUE3RFfVuZLYl X-Google-Smtp-Source: ABdhPJy0dmCHET1SFGJt0YbdWSJ1KQO2GJvR5hEWlIiRXYUBubWwNeAWHjO028SuadZbM4UGPuVjNg== X-Received: by 2002:ad4:536a:: with SMTP id e10mr593390qvv.246.1590094309714; Thu, 21 May 2020 13:51:49 -0700 (PDT) Original-Received: from ?IPv6:2601:184:4180:66e7:bda5:ac5c:1de0:b677? ([2601:184:4180:66e7:bda5:ac5c:1de0:b677]) by smtp.googlemail.com with ESMTPSA id k43sm6713249qtk.67.2020.05.21.13.51.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 May 2020 13:51:48 -0700 (PDT) In-Reply-To: <834ks95cmz.fsf@gnu.org> Content-Language: en-GB Received-SPF: pass client-ip=2607:f8b0:4864:20::f2c; envelope-from=cpitclaudel@gmail.com; helo=mail-qv1-xf2c.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action 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:251183 Archived-At: On 21/05/2020 15.08, Eli Zaretskii wrote: > That would prevent Emacs from controlling what is and what isn't > composed, leaving the shaper in charge. We currently allow Lisp to > control that via composition-function-table, which provides a regexp > that text around a character must match in order for the matching > substring to be passed to the shaper. We never call the shaper unless > composition-function-table tells us to do so. Does this mean that for each font we need to re-encode the font's logic for deciding whether to use a ligature? Some concrete examples: in Iosevka (*, (**, (***, (**** etc are all displayed with the * character vertically centered relative to the (, but a lone * is not centered. In Fira Code, punctuation is context-aware, so the "+" in "A + B" is not the same as the "+" in "a + b". In both of these faces, arrows can be of any length, and in Fira Code you can even mix and match them (see https://raw.githubusercontent.com/tonsky/FiraCode/master/extras/arrows.png). The documentation of Fira Code does recommend composition-function-table here: https://github.com/tonsky/FiraCode/wiki/Emacs-instructions, but it seems like a lot of extra work for each font, isn't it?