Re: Using old fonts

[Hans Hagen via ntg-context <ntg-context@ntg.nl>]

On 11/18/2021 5:36 PM, Gérard Milmeister via ntg-context wrote:
> Using old fonts
> 
> Around 2000 I acquired a collection of fonts, mostly Type 1
> and some TrueType. As it appears they are not fully usable
> in ConTeXt. The two main issues are:
> 
> 1. Kerning and ligatures
> 
> These features can be only be used, if the GPOS and GSUB
> tables are present and adequately filled. Now, the old font
> files do not have these tables, but instead use some
> obsolete (?) form of kerning table, and ligatures are not
> qualified as such, but only trough their Unicode point and
> name (most commonly fi and fl). I used fontforge, which
> creates the GPOS table automatically, added the liga table
> manually, and generated an OTF font file.
> 
> Is there a way to automate this (possibly a fontforge
> script)? The script should also find the ligatures (there
> may also be frac substitutions). Or is there another way
> which leaves the files unchanged?

Are you talking type 1 fonts? These should just work, assuming that you 
have the afm files installed. You need to define them with the right 
features enabled (just like opentype fonts).

> 2. Selecting glyphs from multiple font files
> 
> Often there are additional font files which contain small
> caps (in place of lowercase characters) and old style
> figures (in place of digits), and other variant glyphs and
> additional ligatures (usually the font name contains OsF,
> SC, Alt, or Exp). Sometimes these are not allocated to a
> Unicode point, but only identified by name (e.g.
> "threeoldstyle" or "Esmall"). Is it possible to create some
> sort of virtual feature (such as onum), that will cause
> ConTeXt to take glyphs from another file (but only for
> specified Unicode ranges)? I suppose this can be done with a
> Lua goody.
The fallback mechanism does that (you can define a collection that way). 
One can also try to make features (there are examples in the te st suite).

Hans


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