From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 18849 invoked from network); 13 Jan 2022 17:31:51 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 13 Jan 2022 17:31:51 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 10CFE9D4E4; Fri, 14 Jan 2022 03:31:49 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 318EA9D4B3; Fri, 14 Jan 2022 03:31:33 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=dartmouth.edu header.i=@dartmouth.edu header.b="r4/qvsDh"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id F337A9D4B2; Fri, 14 Jan 2022 03:31:31 +1000 (AEST) Received: from mail-wm1-f42.google.com (mail-wm1-f42.google.com [209.85.128.42]) by minnie.tuhs.org (Postfix) with ESMTPS id 5230D9D4B2 for ; Fri, 14 Jan 2022 03:31:31 +1000 (AEST) Received: by mail-wm1-f42.google.com with SMTP id n19-20020a7bc5d3000000b003466ef16375so5881157wmk.1 for ; Thu, 13 Jan 2022 09:31:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dartmouth.edu; s=google1; h=mime-version:from:date:message-id:subject:to; bh=PjdzZ3V/SWHAp9uHB/RemFIW3mROXf0Z+4WPtiSyozI=; b=r4/qvsDh0zW0LHJOAPdjinSsq6mcTgMl0D9gyZ5bAwlnzsHzV/W1uSwtxcCOAhi9UB XbV0BfIyMTFmi3rjVM9EgyZp9YPCCX3IJX8zE6JXHQftiEIpmj9S5oUNSRpj5/tonKXr MRzYyXN99tz0xatch8SKbkZSpHYb6wlvMVmsCrtMGAXCwkVDmBL+2s9pxnqGjeTalbKl kdN39jTmxpKSG6ILAq2T/J0FWVOiiWnDVXbKAP2BjhuAyRxZM/WTAI0Nuzqku+rpHeiE o7275q1yc+hR4Eh9FlL0Jdx02UkKarPn8qAZUGS2roCCd2RH/n7/YTt8WOSgXjci6d4M U93Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=PjdzZ3V/SWHAp9uHB/RemFIW3mROXf0Z+4WPtiSyozI=; b=VqCPlyLU2gp3fa/1NnOjH4PixNUpek5hUZgD5H58fyRyfZ99OWOmPZQHSEyRxdaAEM JCKH99KqWtJ4wp1YXIckn/9gcGbxnGK1rMkI2f6SPmEHwrkNgn/E2Gw9HGAac9eY3E2R 4WWo2XJcFTfn3Hy3hxo6W53AmJq13xE56TbIBbovY6gzTl4bClXeI7ftfSF+yHZpnJ4u 9cDi4ximLB8dXR6XmRoeVpgaFA/W3XAn1O4T8/L3nxrqjXHDSQd+j30ifMdFYErk4r+k xVZYXezIrfydQEQC0TTiLcslXgWZuk/qZy2tNd0QUXhU6oAO/gh00xlzHO7Pd56ocE05 6uCw== X-Gm-Message-State: AOAM532J6s512akHrCtcgp72ZUtJarrxH1LHQ1fVUuz5fX13CyZA0/5e ztssTvTQ5t450r3XeFh7WVQZrmOuVkQmH8NQbibYvowLYDokiA== X-Google-Smtp-Source: ABdhPJwjiw9oa/R0VJeuzEArAvqZzliZICHmpFmjSrbfuhvgcXnmaYLl0c2jyLsHEHuLOkuHh4z0TzXGLZvWpLQvIhA= X-Received: by 2002:a7b:cb48:: with SMTP id v8mr3479749wmj.157.1642095089478; Thu, 13 Jan 2022 09:31:29 -0800 (PST) MIME-Version: 1.0 From: Douglas McIlroy Date: Thu, 13 Jan 2022 12:31:13 -0500 Message-ID: To: TUHS main list Content-Type: text/plain; charset="UTF-8" Subject: Re: [TUHS] TeX and groff (was: roff(7)) X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" > If I can be so bold as to offer an interpretation: Doug's approximations > treat ellipses as mathematical objects and algorithmically determine what > pixels are closest to points on the infinitesimally-thin curves, while > Knuth's (or one his students') method acknowledges that the curve has a > width defined by the nib Just so. > I find it impossible that neither Knuth nor Hobby were unaware of McIlroy's > work and vice-versa; of course he would have known about and examined troff > just as the Bell Labs folks knew about TeX. We were generally aware of each other's work. My papers on drawing lines, circles, and ellipses on rasters, though, were barely connected to troff. Troff did not contain any drawing algorithms. That work was relegated to the rendering programs that interpreted ditroff output. Thus publication-quality rendering with support for thick lines was outsourced to Adobe and Mergenthaler. Various PostScript or ditroff postprocessors for screen-based terminals were written in house. These programs paid little or no attention to fonts and line widths. But the blit renderers made a tenuous connection between my ellipse algorithm and troff, since my work on the topic was stimulated by Rob's need for an ellipse generator. Doug