From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Image transformations Date: Tue, 25 Jun 2019 07:34:10 +0300 Message-ID: <95554A73-A5B5-4407-A5B4-4F901FF5E6CF@gnu.org> References: <20190613165804.GB11266@breton.holly.idiocy.org> <83d0jhz9za.fsf@gnu.org> <20190613192724.GA11945@breton.holly.idiocy.org> <83zhmlxo6d.fsf@gnu.org> <20190613222626.GA12971@breton.holly.idiocy.org> <83o930y7cl.fsf@gnu.org> <20190615104242.GA13368@breton.holly.idiocy.org> <838su3w0de.fsf@gnu.org> <20190616152259.GA22789@breton.holly.idiocy.org> <83d0jdv68i.fsf@gnu.org> <20190617211332.GA55597@breton.holly.idiocy.org> <83a7e6na26.fsf@gnu.org> <8336jymm0g.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="122814"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: K-9 Mail for Android To: emacs-devel@gnu.org,Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Tue Jun 25 06:35:07 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hfdAh-000VqK-Ea for ged-emacs-devel@m.gmane.org; Tue, 25 Jun 2019 06:35:07 +0200 Original-Received: from localhost ([::1]:56490 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfdAf-0000zS-Q5 for ged-emacs-devel@m.gmane.org; Tue, 25 Jun 2019 00:35:05 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:57316) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hfd9t-0000zM-En for emacs-devel@gnu.org; Tue, 25 Jun 2019 00:34:18 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:50918) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hfd9r-0002oM-Vi; Tue, 25 Jun 2019 00:34:16 -0400 Original-Received: from [109.253.217.27] (port=37214 helo=[10.131.198.228]) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1hfd9q-0007Tu-6h; Tue, 25 Jun 2019 00:34:15 -0400 In-Reply-To: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:238131 Archived-At: On June 25, 2019 6:28:32 AM GMT+03:00, Stefan Monnier wrote: >=20 > >> Also, one of the two matrices can't be computed if the > transformation > >> turns the 2D image into a line (or a point)=2E > > We don't support such transformations=2E >=20 > There's no option to "magnify" by a factor 0? Factor zero will give you zero pixels, which is not what you want=2E But more generally: no, we don't currently support that=2E Did you try it= ? > >> Compared to the cost of handling the image, inverting a 3x3 matrix > >> is probably negligible, tho=2E > > Maybe so, but it still sounds silly to me=2E >=20 > Part of the reason for my question above is to figure out if the > implementation of the API is likely to have such matrix inversion > code internally How can we possibly know for sure, on all supported platforms? > (since it seems quite possible that sometimes one is > preferable and sometimes the other)=2E I admit I don't see why we would have different preferences=2E We need to= comply to public interfaces, which means use what they require=2E