On Tuesday 23 October 2012 04:05:15 Mike Speciner wrote:
I'm not familiar with TeX's kerning facility (and the last I looked, which was a very long time ago, it didn't have any),
Wow. Kerning is described in the "TEXDRA.FT" document Knuth put out in May 1977, well before any version of TeX was actually released. On the other hand, the next version of that document, TEX.ONE in July of the same year, seems to imply no kerning. The first book made with TeX, a keepsake for Knuth's wife's relations made in late 1978, has no kerning. There was definitely kerning by 1981 (in particular, before the big transition from TeX78 to TeX82). Does anyone know more exactly when kerning was introduced to TeX?
but typical kerning is done by a table of character pairs within the same font and size. CTI kerning was done by letter shape and could handle any horizontal juxtaposition of characters, even if they were from different fonts and at different sizes/obliquenesses/baseline (as would happen with subscripts and superscripts, math symbols, greek letters, etc.).
Yes, TeX uses a table of character pairs within each font. So CTI did some kind of optical kerning? Can you say anything about the algorithms used? -- g