From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Cursor drawing Date: Sat, 22 Dec 2018 11:43:31 -0500 Message-ID: References: <838t0kcmpj.fsf@gnu.org> <831s6cc8zy.fsf@gnu.org> <83zht0at4d.fsf@gnu.org> <83woo3bbjw.fsf@gnu.org> <83lg4ibq6x.fsf@gnu.org> <1d7c13bd-8223-4999-8999-41fb4d5570c7@gmail.com> <83imzmboqc.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1545496908 29811 195.159.176.226 (22 Dec 2018 16:41:48 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 22 Dec 2018 16:41:48 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Dec 22 17:41:44 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gakLP-0007e3-W1 for ged-emacs-devel@m.gmane.org; Sat, 22 Dec 2018 17:41:44 +0100 Original-Received: from localhost ([::1]:60399 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gakNW-0007ju-IV for ged-emacs-devel@m.gmane.org; Sat, 22 Dec 2018 11:43:54 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:45677) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gakNN-0007j8-2K for emacs-devel@gnu.org; Sat, 22 Dec 2018 11:43:45 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gakNI-0003Td-Sq for emacs-devel@gnu.org; Sat, 22 Dec 2018 11:43:45 -0500 Original-Received: from [195.159.176.226] (port=40229 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gakNI-0003SU-Ln for emacs-devel@gnu.org; Sat, 22 Dec 2018 11:43:40 -0500 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1gakL8-0007Qb-9L for emacs-devel@gnu.org; Sat, 22 Dec 2018 17:41:26 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 16 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:cslbpA3OxLNgrZ9NyWszqtgJ02A= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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:231957 Archived-At: > This kind of drawing cannot be part of the display engine, since you > want to draw over the text, and thus redisplay will overwrite portions > of your arrows. That's why I was suggesting a separate layer. > And probably also remove those at the beginning of each redisplay > cycle, to avoid leaving artifacts on screen when/if redisplay decides > to scroll. Another way to look at it is that scrolling the display's pixels can only be used when both layers (the glyph-matrix and the overlay) were moved together. Stefan