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Re: PostScript font installation: my evolving tools...
Thierry Bouche writes:
> I believe [Alan Jeffrey only experimented] until his published example
> in TUGboat looked good! Much more side-bearing corrections & skewkerns
> are required if you intend to do something serious with mathptm. I
> wrote for my personnal use a shell script that corrects all side-bearings/
> advance width & skewkerns from a text font (essentially: avoiding
> negative side bearings, and computing the italic correction to have
> an honest skewkern). I had however to correct a lot of them by hand.
> I am not really interested in sharing the script as it demonstrates
> my poor programming abilities far too much.
Just what is a skewchar/skewkern anyway, and how does one ensure that
it is honest?
Now that you mention it, I'm not entirely convinced I'm working out
italic corrections in the most ideal way, either. So far, I've gone with
the established method, which seemed to be to use the right sidebearing
of the font, if it was negative (making it positive, of course). However,
what I feel I ought to be doing is looking also at the right sidebearing
of the upright font to. This would mean that even after italic correction,
an italic `f' would have a slight negative right sidebearing. Does this
seem sensible or crazy?
I have two ideas for creating math letters. One is to follow a scheme
like Thierry's, which is to decide we are only prepared to tollerate
negative sidebearings up to a certain limit (I think it may be wrong
to elimiate them entirely, `f' in CMMI10 has a right sidebearing of
-62 AFM units and `j' has a negative sidebearing of -13 AFM units).
The other is to take a pair math and text fonts (e.g. CMMI10 & CMTI10
or LucidaNewMath-Italic & LucidaBright-Italic), which I shall call the
source fonts, and attempt to steal their wisdom and apply it another
font, which I shall call the candidate font. First, we make the candidate
text font `more like' the source text font. The difference I'm thinking
of here, is that some fonts, like Computer Modern, put most of their
inter-letter space in the left sidebearing, whereas most PostScript
fonts (except Lucida) put it in the right sidebearing. So, if we work
out the difference between average left and right sidebearings of the
source and those of the candiate text fonts, we can then add these
average left and right deltas to to the each glyph candidate text font.
Then for every glyph we look at the difference between left and right
sidebearings of source text and math fonts, and add that difference to
the left and right sidebearings of the modified candiate font.
Thoughts on both of these methods would certainly be welcome,