220 32720 article Path: news.gmane.org!.POSTED!not-for-mail From: Bengt Gustafsson Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Why do we include a Matrix and Vector class into the proposed 2D Graphics Library? Date: Sat, 10 Jun 2017 11:42:21 -0700 (PDT) Lines: 153 Approved: news@gmane.org Message-ID: References: <7e3ee19d-f758-4d38-a015-0c474424073d@isocpp.org> <20170609115017.5132345.91153.30981@gmail.com> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2020_32189902.1497120141813" X-Trace: blaine.gmane.org 1497120144 29110 195.159.176.226 (10 Jun 2017 18:42:24 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 10 Jun 2017 18:42:24 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCRIRSPDTQIRBDX36DEQKGQEDCWVKQA@isocpp.org Sat Jun 10 20:42:20 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pg0-f70.google.com ([74.125.83.70]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dJlL0-0007JK-P0 for gclcip-std-proposals@m.gmane.org; Sat, 10 Jun 2017 20:42:18 +0200 Original-Received: by mail-pg0-f70.google.com with SMTP id d13sf37972708pgf.12 for ; Sat, 10 Jun 2017 11:42:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=wh/Lu9NJcj+XUdDCsTA28b8z/X6dUuW3Gr3XROGdB00=; b=oRG+Z93wyyPmdrO3F1RB8RpttYQR6lyMLcH9jYVL0d5VeA/tkjbgTYEipQUhSU8W0o 1Z1xd6A3vY6kBJnKwS7N0AuKgDaEIsYbfdBarnzioU7wZrFVNp3GuZPRpneEDbHhLTss czz5pMSMwh18h+J+1qF5fJybnqcOX+8oGap/23CMKdz1kB8pQGcKHhTrtSYpEKYreOpo aKMwu5X5jhPWzJ82a7ZL6ByJa9VzHFyK4//JLJBp4eWemUwLj3xgOB8Pt6s2nmiwZuFx Q/vZMTogcwAkCaRGgZxivovpkGsQlaxHse7k9D/71bJcbdEUMAIGfGM5xjoYYpaF/6RI utXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=wh/Lu9NJcj+XUdDCsTA28b8z/X6dUuW3Gr3XROGdB00=; b=to0prTvWJsJhbIk5GCgXDdP3Du6pfnPp8UAAugpQtWlbgTXeXu+GPrHF0PS27DykHd ArG6ssYq1XhI8Wvl5AokPTgo3A6RLxkNI5a/CM/vkAA1yToif0rhQr42hnXTb5AHN6q5 LHFb7KBE+hQ3+hxIf2GpD6d+asU2+WeO1qOj97sUzrxLepZeoHgck5S3/F8/kUY8c1mS eoT2pxCbDyLBNscQhbD6eNKnUn0qUU8UgiNjLQ9HyUDDvjs1GbDPGQI1wjghCnYZ59PD u5UGj/82NGC01ErzVaMf4VgIJ+AaB2ygsuZWNmZIBrQj454dkXTilrRdiJdO/cUs9tGv EKvg== X-Gm-Message-State: AODbwcDF8XPNue8qWoSIF738RITbh+mbVVmCwxZ2c0tDZPkgjOdI1SMv B6EqwDa0kjnMkw0j X-Received: by 10.99.171.9 with SMTP id p9mr16240460pgf.0.1497120143673; Sat, 10 Jun 2017 11:42:23 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.34.196 with SMTP id y62ls12916187ota.1.gmail; Sat, 10 Jun 2017 11:42:22 -0700 (PDT) X-Received: by 10.157.48.161 with SMTP id s33mr1126765otc.1.1497120142390; Sat, 10 Jun 2017 11:42:22 -0700 (PDT) In-Reply-To: X-Original-Sender: bengt.gustafsson@beamways.com 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:32720 Archived-At: ------=_Part_2020_32189902.1497120141813 Content-Type: multipart/alternative; boundary="----=_Part_2021_264905610.1497120141813" ------=_Part_2021_264905610.1497120141813 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Here I think you are totally wrong. A lack of common vocabulary types is in= =20 my view a major deterrant from using C++. By providing vocabulary types=20 like a (mathematical) vector and matrix we offer the possibility for third party library vendors to create libraries that can be used=20 together seamlessly. If C++ had come with a more complete set of vocabulary= =20 types long ago we wouldn't have had CString, QString and wxString nor would= =20 we have QPoint, wxPoint, eigen::vector2i, osg::vec2d all with the same=20 contents but incompatible. This would have been very helpful to us who use= =20 lots of third part libraries to perform complex tasks. So on this point I say: Better late than never. As for the graphics2d library I agree that it is too tangential to be=20 standardized but vectors and matrices (preferrably as one n-dimensional=20 template class) are not. With it third party libraries for 2D graphics, 3D= =20 graphics, data analysis, image processing, and what not can be used=20 together with less pain, reducing the need to standardize the libraries=20 themselves (possibly with separate sets of such vocabulary types). Den l=C3=B6rdag 10 juni 2017 kl. 18:58:13 UTC+2 skrev Nicol Bolas: > > On Saturday, June 10, 2017 at 12:02:46 PM UTC-4, Bengt Gustafsson wrote: >> >> @Jakob: I had the same feeling when reading this proposal: These types= =20 >> should not be part of a graphics library, but instances of a general=20 >> vocabulary matrix type. There are a couple of requirements to bring back= =20 >> from the 2D graphics proposal: >> >> - A vector/matrix type must be possible to instantiate with fixed size. >> - A 2 element vector should have members named x and y. >> > > The problem with all this is that, from the perspective of the graphics= =20 > library, generalizing these things is essentially irrelevant and pointles= s.=20 > Sure, it makes those types more useful for other things, but it doesn't= =20 > make them more useful for the graphics library. > > Having to get a full-fledged vector/matrix library through the committee= =20 > is a lot harder than just saying, "here's a few types that exist for a=20 > narrow purpose". You'd essentially be delaying the standardization of the= =20 > graphics library for things that have nothing to do with graphics. > > Now granted, I don't think the graphics library should be standardized *a= t=20 > all*, but if it's going to happen, I'd rather not see it delayed due to= =20 > issues that are tangential to that library's needs. > > The only generic issues I think need to be accounted for is the ability t= o=20 > transform these types into `span`s (and therefore defining them explicitl= y=20 > to contain arrays). But that's contingent on standardizing `span` itself. > --=20 You received this message because you are subscribed to the Google Groups "= ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp= ..org/d/msgid/std-proposals/d71c480f-bcd2-4051-9f92-523e3e6fc563%40isocpp.or= g. ------=_Part_2021_264905610.1497120141813 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Here I think you are totally wrong. A lack of common vocab= ulary types is in my view a major deterrant from using C++. By providing vo= cabulary types like a (mathematical) vector and matrix we offer the possibi= lity
for third party library vendors to create libraries that can be us= ed together seamlessly. If C++ had come with a more complete set of vocabul= ary types long ago we wouldn't have had CString, QString and wxString n= or would we have QPoint, wxPoint, eigen::vector2i, osg::vec2d all with the = same contents but incompatible. This would have been very helpful to us who= use lots of third part libraries to perform complex tasks.

<= /div>
So on this point I say: Better late than never.

As for the graphics2d library I agree that it is too tangential to = be standardized but vectors and matrices (preferrably as one n-dimensional = template class) are not. With it third party libraries for 2D graphics, 3D = graphics, data analysis, image processing, and what not can be used togethe= r with less pain, reducing the need to standardize the libraries themselves= (possibly with separate sets of such vocabulary types).


De= n l=C3=B6rdag 10 juni 2017 kl. 18:58:13 UTC+2 skrev Nicol Bolas:
On Saturday, June 10, 20= 17 at 12:02:46 PM UTC-4, Bengt Gustafsson wrote:
@Jakob: I had the same feeling when reading t= his proposal: These types should not be part of a graphics library, but ins= tances of a general vocabulary matrix type. There are a couple of requireme= nts to bring back from the 2D graphics proposal:

- A vec= tor/matrix type must be possible to instantiate with fixed size.
= - A 2 element vector should have members named x and y.

The problem with all this is that, from the perspective of th= e graphics library, generalizing these things is essentially irrelevant and= pointless. Sure, it makes those types more useful for other things, but it= doesn't make them more useful for the graphics library.

Having = to get a full-fledged vector/matrix library through the committee is a lot = harder than just saying, "here's a few types that exist for a narr= ow purpose". You'd essentially be delaying the standardization of = the graphics library for things that have nothing to do with graphics.
<= br>Now granted, I don't think the graphics library should be standardiz= ed at all, but if it's going to happen, I'd rather not see i= t delayed due to issues that are tangential to that library's needs.
The only generic issues I think need to be accounted for is the abilit= y to transform these types into `span`s (and therefore defining them explic= itly to contain arrays). But that's contingent on standardizing `span` = itself.

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