His book _TeX and METAFONT_ (about the initial public release) goes into these difficulties in greater detail and includes the charming response by his wife when shown some initial efforts:
>Why don't you make them _S_ shaped?
To some degree, this problem was eventually solved, c.f., the five volume set _Computers and Typesetting_:
https://www-cs-faculty.stanford.edu/~knuth/abcde.html
but then one had the effort to create a new typeface set for math equations by the AMS, eventually named Euler as written up in "AMS Euler — a new typeface for mathematics". _Scholarly Publishing_ and so forth, but arguably, things went awry in that rather than capture the ductus of Prof. Zapf's pen, and model based on that stroke and a pen shape, the expedient approach of simply modeling the outline was arrived at and implemented due to the difficulty and lengthy time required for the idealized approach.
Another consideration may have been that there doesn't seem to be an available algorithm which is robust and accurate and automatic for determining the curves which describe the union of arbitrary Bézier curves (some projects get around this by making high resolution pixel images and tracing them).
For the work on Euler, this article¹ (https://www.sciencedirect.com/science/article/pii/S240587262...) goes into the whole Digital Typography program at Stanford for whom, one of the projects was creating those outlines for the Euler math fonts. It’s worth remembering that at the time, not only was Metafont the only outline-based font technology,² but things like scanners were rare to nonexistent and the bitmaps that were used to determine coordinates for the curves of the fonts were hand-drawn on fine-lined graph paper (and sent to Hermann Zapf for approval).
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1. Funnily enough this is the second time in two days that I’ve shared this article, albeit in different contexts.
2. As far as I know, although I could be wrong.
> was Metafont the only outline-based font technology
Surely Karow's Ikarus was earlier than that.
One of the main innovations of Metafont was the use of "pen"s, so that one would describe a single path and the software would trace it and imitate the use of one or more pens, to end with an outline of something with thickness, and essentially more curves. It mimics how drawing and writing actually happens.
AFAIK, Zapf did not like this approach at all, as he was used to design typefaces the traditional way, by specifying all the curves. Richard Southall embraced the new paradigm and used Metafont as it was supposed to be used, but produced only a couple of demo typefaces (mainly the nmt family) and a handful of commercial ones (I can now only remember Colorado, with Ladislas Mandel, used in the phone directories of US West). I think he also implemented Melior, but of course this was never distributed as it was a proprietary Zapf design.
Note: all the above are based on recollections of my discussions with Zapf, Southall, and Knuth, in the distant past. All my relevant printed materials are in a different country right now, and I don't have easy access to them.
Yeah, _Digital Typefaces_ by Peter Karow was first published in 1986 (in German) and the company had been running for a long while before then, the software having been introduced at ATypI in Warsaw in 1975.
_TeX and METAFONT_ (the book) was published in 1979 (I still vividly remember checking a copy out of the local college library as a high school student in 1983) having its initial release in 1978, after being precipitated by the infamous second edition galley proofs on TAoCP 30 March 1977.
Ah, I suspected it wasn’t the first, it’d just been a long time since I dealt with some of this history. 30 years ago, I had the entirety of Gutenberg to Emigre at the front of my brain but much of it has vanished since.
Yeah, Barbara Beeton was kind enough to send me a copy of the AMS report for which I am _very_ grateful.
Didn't mean for my post to come across as cavalier --- it's a _very_ tough row to hoe, and even now, I don't think that there are good solutions in this space (but I haven't checked for a while, been out of the typography scene for a while now --- I'd love to be wrong). Ironically, my current project
https://github.com/WillAdams/gcodepreview
is circling back to the underpinnings of this sort of thing (I need to make a single stroke font so as to make it easier to set text in CNC projects) and I'm hoping to approach this from the bottom up and eventually arrive at a visual and interactive version of METAFONT/POST which will also work as a general-purpose drawing program (so that I'll have one to use when I can no longer use Freehand/MX) --- hopefully that will then allow me to finish a compleat digital version of Warren Chappell's typeface designs as we discussed peripherally ages ago.