220 8892 <4305077.qmkjCE1Vbu@tjmaciei-mobl2> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Comments on 2d api for c++ N3888.pdf Date: Tue, 28 Jan 2014 08:46:43 -0800 Lines: 103 Approved: news@gmane.org Message-ID: <4305077.qmkjCE1Vbu@tjmaciei-mobl2> References: <9105f9b2-e15d-4bf8-a4a1-65ebc3657eb0@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1663592.vR6aL1r8oT"; micalg="pgp-sha1"; protocol="application/pgp-signature" X-Trace: ger.gmane.org 1390927609 18586 80.91.229.3 (28 Jan 2014 16:46:49 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 28 Jan 2014 16:46:49 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBAF6T6LQKGQE4YLO24A@isocpp.org Tue Jan 28 17:46:58 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-ea0-f198.google.com ([209.85.215.198]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1W8BoP-00065P-BT for gclcip-std-proposals@m.gmane.org; Tue, 28 Jan 2014 17:46:57 +0100 Original-Received: by mail-ea0-f198.google.com with SMTP id h14sf1321144eaj.1 for ; Tue, 28 Jan 2014 08:46:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:user-agent :in-reply-to:references:mime-version:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=fy9X8qF1H+tfGHihdV/klohqpBMKhjrYZ27fTv/z6x8=; b=Pj46jEXXAomAnxpQmRwOTDusJZw95CaZXcLaOc/dCrkZrmPBSJ0ssmPZB/5S35g/R4 t9ufi1edjHV3k58ZHKbVGxnFR/6VVCUw8R/wp0ZZ55GO3Y58VJDuYQQK9ym/O46tfGQ2 LIzmv82LcG8m8zn1V1EockTvbJSp+bNI8VJpajuUjbjBGql7ZOMzA0/2YFvouCELfDGB KHu3ebqIh9n9XhJ2yzlcS4zPsERvH1Y93XMkZDj2FCWx99k2qbmVlAwjPzUZjwZ7jNta 0WDHT7dZZPBWXOBVLNYRIXPrk4buNljVGWaCgMNfawVD5AoOzTAeeojyzPIZfNFWAgaB 7Dtw== X-Gm-Message-State: ALoCoQkOyh1omFa+ccRz+GuQ88KIpplQa3467zdznRBiT0ZXvkFAxVhYjxDAYMx4ReMTWrBq4u/u X-Received: by 10.14.246.4 with SMTP id p4mr1461469eer.3.1390927616953; Tue, 28 Jan 2014 08:46:56 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.189.174 with SMTP id gj14ls1191172wic.6.canary; Tue, 28 Jan 2014 08:46:55 -0800 (PST) X-Received: by 10.204.71.5 with SMTP id f5mr3105468bkj.25.1390927615711; Tue, 28 Jan 2014 08:46:55 -0800 (PST) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by mx.google.com with ESMTP id ed5si7971771bkc.122.2014.01.28.08.46.55 for ; Tue, 28 Jan 2014 08:46:55 -0800 (PST) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) client-ip=2a01:4f8:d13:f81:21c:14ff:fe01:12a3; Original-Received: from tjmaciei-mobl2.localnet (unknown [IPv6:2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by gondolin.macieira.info (Postfix) with ESMTPSA id E5DD612C002 for ; Tue, 28 Jan 2014 08:46:54 -0800 (PST) User-Agent: KMail/4.12 pre (Linux/3.9.10-100+i915fix.fc17.x86_64; KDE/4.11.60; x86_64; git-8054221; 2013-08-01) In-Reply-To: X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) smtp.mail=thiago@macieira.org Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:8892 Archived-At: --nextPart1663592.vR6aL1r8oT Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" On ter=E7a-feira, 28 de janeiro de 2014 09:44:08, Matthew Woehlke wrote= : > The worst of that is related to text rendering=B9. If you're excising= that > anyway, it's not an issue. The rest I suspect is either support class= es > that should be part of the API anyway (e.g. QImage) or readily ported= > (e.g. QVector -> std::vector). > (=B9 for good reason; as mentioned, text rendering, especially when y= ou > start getting into localization intricacies, is hard.) Text rendering and localisation represent probably 80% or more of the i= nstall=20 size of combined QtCore and QtGui, due to the CLDR and Unicode tables i= n Qt=20 and in ICU. And then we have external dependencies like fontconfig and = freetype=20 to get fonts, harfbuzz to get shaping correct, classes like=20 QTextBoundaryFinder to find where to do word-splitting... This part of the discussion is quite heated. What Michael proposed is t= o limit=20 the required font and text handling capabilities to what Cairo offers i= n the=20 toyfont, though implementations would be welcome to do the whole thing.= > > This is untenable. Native handles are a nice, proven abstraction fo= r > > exposing platform-specific functionality without being compelled to= > > standardize all of those platforms. >=20 > As I understood it, the point here is that the API should be agnostic= to > the engine. Ideally to the extent that the engine can be changed with= out > recompiling code. This is the case with e.g. Qt, which allows swappin= g > out the underlying engine via an environment variable. >=20 > Exposing too much of the underlying guts is an invitation to write > non-portable code. Which might be necessary. Not providing the native handles limits the=20= usefulness to only the API that is provided, no extension possible.=20 Qt provides the native handles for the widgets, for example, and that a= llows=20 applications like window managers and desktop fixtures to be developed.= They'd=20 be impossible without platform-specific code. PS: the swapping of the engine was removed in Qt 5 because there's only= one=20 engine left. > I've written a number of Qt and/or OpenGL applications, and can't thi= nk > of any case in which I've needed to deal directly with e.g. X objects= .. > > Per above, this is actively *harmful* to writing portable code and IM= HO > should be strongly discouraged. Even on a single platform, it preclud= es > (or at least, makes much more difficult) engine agnosticism. Discouraged, yes. But still necessary: those applications might be few = and far=20 between, but they exist. --=20 Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center PGP/GPG: 0x6EF45358; fingerprint: E067 918B B660 DBD1 105C 966C 33F5 F005 6EF4 5358 --nextPart1663592.vR6aL1r8oT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. 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