From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Emacs canvas support Date: Wed, 29 Apr 2020 20:38:07 +0300 Message-ID: <83h7x2xke8.fsf@gnu.org> References: <875zdikdge.fsf.ref@yahoo.com> <875zdikdge.fsf@yahoo.com> <834kt21yyo.fsf@gnu.org> <87zhau1uog.fsf@yahoo.com> <83sggmzjp8.fsf@gnu.org> <87mu6u1tii.fsf@yahoo.com> <83o8raziis.fsf@gnu.org> <877dxy1smz.fsf@yahoo.com> <87o8rae0ao.fsf@randomsample> <83lfmexmfp.fsf@gnu.org> <20200429171619.GB20842@tuxteam.de> <83imhixkva.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="81639"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: tomas@tuxteam.de Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Apr 29 19:40:00 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 1jTqgi-000L6C-IY for ged-emacs-devel@m.gmane-mx.org; Wed, 29 Apr 2020 19:40:00 +0200 Original-Received: from localhost ([::1]:56952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTqgh-0005AV-Jr for ged-emacs-devel@m.gmane-mx.org; Wed, 29 Apr 2020 13:39:59 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:56906) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTqfF-0003UG-7p for emacs-devel@gnu.org; Wed, 29 Apr 2020 13:38:29 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:59892) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTqfE-0000Zy-Lq; Wed, 29 Apr 2020 13:38:28 -0400 Original-Received: from [176.228.60.248] (port=3682 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jTqfD-0002JY-JI; Wed, 29 Apr 2020 13:38:28 -0400 In-Reply-To: <83imhixkva.fsf@gnu.org> (message from Eli Zaretskii on Wed, 29 Apr 2020 20:27:53 +0300) 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:248170 Archived-At: > Date: Wed, 29 Apr 2020 20:27:53 +0300 > From: Eli Zaretskii > Cc: emacs-devel@gnu.org > > That's not how Emacs controls what's on display. It basically > represents each window as a 2D array of glyphs, each one of which has > a certain graphical representation. The representation itself is of > no concern to the display engine (well, almost); the only thing it > cares about is the metrics of each glyph, because that's what it needs > to do layout calculations. Oh, and one more important aspect: everything that winds up on display must come from some buffer or some Lisp string. It could be a special text property or somesuch, but it must be found by walking some buffer or some known-in-advance Lisp string, because that's what top-level display functions do: they iterate over these objects, and produce the glyphs based on what they find there.