From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Lars Ingebrigtsen Newsgroups: gmane.emacs.devel Subject: Re: [PATCH] avoid hard-coded assumptions in image scaling Date: Sun, 02 May 2021 22:51:49 +0200 Message-ID: <87fsz4g8pm.fsf@gnus.org> References: <87eeeoopnt.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39238"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: emacs-devel@gnu.org To: "James N. V. Cash" Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun May 02 22:52:41 2021 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 1ldJ4x-000A4O-C4 for ged-emacs-devel@m.gmane-mx.org; Sun, 02 May 2021 22:52:39 +0200 Original-Received: from localhost ([::1]:43056 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ldJ4w-0005U5-E0 for ged-emacs-devel@m.gmane-mx.org; Sun, 02 May 2021 16:52:38 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:46060) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ldJ4K-00052y-8t for emacs-devel@gnu.org; Sun, 02 May 2021 16:52:03 -0400 Original-Received: from quimby.gnus.org ([2a01:4f9:2b:f0f::2]:51816) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ldJ4H-0002rg-6K for emacs-devel@gnu.org; Sun, 02 May 2021 16:52:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnus.org; s=20200322; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date: References:Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=t8xhMFQQnV7IzMjZKTBsS1pT5scqHJ8ATb68snCHTes=; b=pTbkOQp07GvywS9ZuaX1Sb0DIr b9EMFNp+WO3lZyWC5SBTe/bvO2mvS+gw6Mz7wEmUCpxUW/8ZCGQGI66dO0k7qw0bkixCjhuYKklYe h/ovDHsnXO6DNcBMcnqcI75AHoa8/PZSSscC0i0C8kapMdMVutc/8SjEd5+++uM2gmio=; Original-Received: from cm-84.212.220.105.getinternet.no ([84.212.220.105] helo=xo) by quimby.gnus.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ldJ4B-00047i-Rf; Sun, 02 May 2021 22:51:54 +0200 X-Now-Playing: Laura Jean's _The Hunter's Ode_: "The Golden Afternoon" In-Reply-To: <87eeeoopnt.fsf@gmail.com> (James N. V. Cash's message of "Sun, 02 May 2021 16:18:30 -0400") Received-SPF: pass client-ip=2a01:4f9:2b:f0f::2; envelope-from=larsi@gnus.org; helo=quimby.gnus.org 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no 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:268782 Archived-At: "James N. V. Cash" writes: > In image-compute-scaling-factor in images.el, it currently hard-codes > the assumption that the average character width is 10 pixels. Since > `frame-char-width` gives this information though, it seems like it's less > error-prone to use that function instead of assuming. [...] > + ;; We should scale all images according to how wide they are. > + ;; But don't scale images down. > + (if (< width (frame-char-width)) > 1 > - (/ (float width) 10)))) > + (/ (float width) (frame-char-width))))) The point of the heuristic here is that we want to scale images up on HiDPI screens, so the current code gives me a scaling factor of 2.3. (I've got a 14" 4K screen.) (frame-char-width) => 23 With your patch, it'll return 1, of course, which is exactly the opposite of what we want. (The function could just have used (frame-char-width) divided by ten, I guess, instead of computing it itself.) -- (domestic pets only, the antidote for overdose, milk.) bloggy blog: http://lars.ingebrigtsen.no