From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Po Lu Newsgroups: gmane.emacs.help Subject: Confusing issue with redisplay Date: Thu, 19 Aug 2021 15:36:02 +0800 Message-ID: <875yw1lwd9.fsf@yahoo.com> References: <875yw1lwd9.fsf.ref@yahoo.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="29263"; mail-complaints-to="usenet@ciao.gmane.io" To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Thu Aug 19 15:58:21 2021 Return-path: Envelope-to: geh-help-gnu-emacs@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 1mGiYm-0007Qr-Kt for geh-help-gnu-emacs@m.gmane-mx.org; Thu, 19 Aug 2021 15:58:20 +0200 Original-Received: from localhost ([::1]:41514 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mGiYl-0002Cm-CX for geh-help-gnu-emacs@m.gmane-mx.org; 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Thu, 19 Aug 2021 07:36:12 +0000 Original-Received: by kubenode519.mail-prod1.omega.sg3.yahoo.com (VZM Hermes SMTP Server) with ESMTPA ID 7b68294a3e5af5cb7771f8098532c29a; Thu, 19 Aug 2021 07:36:06 +0000 (UTC) X-Mailer: WebService/1.1.18850 mail.backend.jedi.jws.acl:role.jedi.acl.token.atz.jws.hermes.yahoo Received-SPF: pass client-ip=66.163.189.82; envelope-from=luangruo@yahoo.com; helo=sonic306-20.consmr.mail.ne1.yahoo.com X-Spam_score_int: -1 X-Spam_score: -0.2 X-Spam_bar: / X-Spam_report: (-0.2 / 5.0 requ) BAYES_40=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Thu, 19 Aug 2021 09:57:33 -0400 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:132612 Archived-At: I've run across an odd issue whilst bringing up a new window system: it seems that each glyph overlaps its surroundings by exactly one pixel, which leads to visible artifacting. For instance, while I would have expected the output from redisplay to be as follows: ["f" CHAR_GLYPH x=0 width=15 y=0 height=15] ["o" x=16 width=15 y=0 height = 15] In this case "o" would actually start at 15 on the X axis, causing the glyph "f" to be partially overdrawn. What is even more confusing is that the output of redisplay seems to exhibit the same overlap under other window systems, whilst no artifacting is visible. Am I missing something particularly obvious? Any help would be appreciated. Thanks in advance!