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From: Douglas McIlroy <douglas.mcilroy@dartmouth.edu>
To: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] TeX and groff (was: roff(7))
Date: Thu, 13 Jan 2022 12:31:13 -0500	[thread overview]
Message-ID: <CAKH6PiVnX+b526Lp9PnDvwqWn6G3p1hMiTi=mMGhYkFMo5sQiA@mail.gmail.com> (raw)

> 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

             reply	other threads:[~2022-01-13 17:31 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-13 17:31 Douglas McIlroy [this message]
  -- strict thread matches above, loose matches on Subject: below --
2022-01-12  2:49 Jon Steinhart
2022-01-12 10:38 ` Ralph Corderoy
2022-01-12 17:53   ` Jon Steinhart
2022-01-12 18:27     ` G. Branden Robinson
2022-01-12 19:02       ` John Cowan
2022-01-11 13:37 Nelson H. F. Beebe
2022-01-10 21:12 Bakul Shah
2022-01-10 21:06 Jon Steinhart
2022-01-11 11:06 ` Ralph Corderoy
2022-01-11 14:52   ` John Cowan
2021-12-31 15:47 [TUHS] roff(7) Douglas McIlroy
2021-12-31 23:07 ` George Michaelson
2021-12-31 23:40   ` Larry McVoy
2022-01-01  0:56     ` [TUHS] TeX and groff (was: roff(7)) Greg 'groggy' Lehey
2022-01-01  3:15       ` Larry McVoy
2022-01-10 19:00         ` Blake McBride
2022-01-10 20:21           ` Jon Forrest
2022-01-11 22:48             ` Blake McBride
2022-01-11 23:18               ` Larry McVoy
2022-01-12  1:19                 ` Dave Horsfall
2022-01-12  1:46                 ` Blake McBride
2022-01-12  2:12                 ` Bakul Shah
2022-01-12 15:49                   ` Larry McVoy
2022-01-12 16:22                     ` Adam Thornton
2022-01-12  0:06               ` Jon Steinhart
2022-01-12  1:48                 ` Blake McBride
2022-01-12  0:29               ` Nemo Nusquam
2022-01-12  1:53                 ` Blake McBride
     [not found]               ` <E3CC4B8A-4E88-4339-A4D3-4ED26BA80620@gmail.com>
2022-01-12  0:44                 ` Jon Forrest
2022-01-12  2:00                   ` Blake McBride
2022-01-12  2:10                     ` David Arnold
2022-01-12  2:26                       ` Adam Thornton
2022-01-12 19:54                     ` John Cowan
2022-01-13 10:13                       ` Thomas Paulsen
2022-01-13 20:00                         ` John Cowan
2022-01-10 20:33           ` Larry McVoy
2022-01-10 20:37             ` Richard Salz
2022-01-10 21:04               ` Dan Cross
2022-01-10 21:48                 ` Nemo Nusquam
2022-01-11  2:25                 ` Lyndon Nerenberg (VE7TFX/VE6BBM)
2022-01-11  2:47                   ` Larry McVoy
2022-01-12  1:19             ` Mary Ann Horton
2022-01-12  2:03               ` Blake McBride
2022-01-12  2:10               ` Bakul Shah
2022-01-12  3:44                 ` Dan Cross
2022-01-12 16:48               ` Steffen Nurpmeso
2022-01-10 20:46           ` Steffen Nurpmeso

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