Re: [groff] Fonts, PDF images, groff vs. heirloom troff

[aksr]

Hello,

On Tue, Jan 22, 2019 at 08:27:08AM +0100, Pierre-Jean Fichet wrote:
> Neatroff do both of these. It suports OpenType fonts, but does not offer
> as much control as Heirloom Troff does.

Are you sure about that?  Anyway, even though I use both,
I often prefer Neatroff (it is very good).

If the font has typographic features,[1] it's very easy to enable them
(one or more) or to disable them in Neatroff (.ff F +F1 -F2).
Examples:

   .ff I +sinf             (enable scientific inferiors: H₂0 (H20))
   .ff R +onum +frac       (enable oldstyle figures and fractions 1/4)
   .ff R +onum +frac -tnum (enable oldstyle figures, fractions, disable
                            proportional figures)
   etc.

You can also set "scriptstags".[2]  Script tags are important for
appropriate kerning, glyphs etc. (.ffsc F SC LN).
For example, to use Serbian Cyrillic glyphs instead of the Russian ones
(because Serbian uses different italic glyphs for some letters):

   .ffsc R cyrl SRB
   .ff   R +locl (enable localized forms, very important!)
   etc.

More examples:

   .ff I +aalt (enable alternate forms of the character)
   .ff I +calt (enable contextual alternats)
   .ff R +sups (replace character with superscript version)
   .ff R +subs (replace character with subscript version)
   etc.

Code is clean and the Neatroff's author is very helpful.


Best regards.

[1] https://en.wikipedia.org/wiki/List_of_typographic_features
[2] 
https://docs.microsoft.com/en-us/typography/opentype/spec/chapter2#scripts-and-languages