[Tex/LaTex] Context : How to install and use new opentype (math) fonts

contextmath-fontsopentype

Motivation : I'm a die-hard user of LaTeX which is intrigued by ConTeXt and try to learn enough of it to be able to judge on its usability. For now, I'm limiting myself to Mark IV/LuaTeX (Mark II seems to have stopped evolving). I use the current TeXLive distribution (as packaged by Debian).

I recently stumbled on an unexpected difficulty : Opentype math fonts. The current situation is that a lot of the (few) available Opentype Math fonts can be used "out of the box" ; a bit of exploration shows that some support scripts for these fonts exists in $TEXMF/tex/context/fonts/mkiv/.

However, I have been unable to read, guess or divine the goals or structure of these files. As a consequence, I have been unable to cajole Context to use the following couples of Opentype tex / Opentype math fonts, which have recently become available :

GFS Neohellenic / GFS Neohellenic Math (CTAN)
Fira Sans / Fira Math
STIX Two family (CTAN).

I have been able to use the text fonts ; for example :

\definefontfamily [gfsneohellenic] [serif] [GFSNeohellenic]
\setupbodyfont [gfsneohellenic]

but any attempt to use math fails early. However, using the first two of these may allow to get a correct typesetting of maths with a sans typeface consistent with the text font (see this question for amplification…)

[ On the other hand, using them in LuaLaTeX is a piece of cake : link them to the "right" place, re-run font-cache, and you're set… ]

I am not (yet) familiar enough with the ConTeXt documentation to understand the mkiv/.lfg scripts which seem to be the origin of ConTeXt support for these math fonts.

Question(s) : Where should I look for documentation of this feature ? Or is there some "magic" script allowing for the creation of such scripts ?

Best Answer

Where should I look for documentation of this feature?

There is a manual which is distributed with ConTeXt standalone, called Fonts out of ConTeXt. It is also sometimes referred to as “the new font manual”.

Or is there some "magic" script allowing for the creation of such scripts?

No, there is no magic script to generate these so-called typescripts. But the structure is straight-forward and it is really easy to roll your own.

The procedure is always the same. You define a typescript for a certain family and assign font files to predefined names. For example

\starttypescript [sans] [fira]
  \definefontsynonym [Sans] [file:FiraSans-Regular.otf] [features=default]
\stoptypescript

This tells ConTeXt that when the Sans version is requested it should load FiraSans-Regular.otf and apply the default font features to it.

The .lfg files (Lua Font Goodies) are more complicated but you mostly need those if you have to patch math fonts, you want to expose special math font features to ConTeXt, or you have to define virtual fonts. In a first approximation they are usually not needed.

Here is a full, yet simple example for the Fira font.

\starttypescriptcollection [fira]

  \starttypescript [sans] [fira]
    \setups[font:fallback:sans]
    \definefontsynonym [Sans]           [file:FiraSans-Regular.otf]       [features=default]
    \definefontsynonym [SansItalic]     [file:FiraSans-RegularItalic.otf] [features=default]
    \definefontsynonym [SansBold]       [file:FiraSans-Bold.otf]          [features=default]
    \definefontsynonym [SansBoldItalic] [file:FiraSans-BoldItalic.otf]    [features=default]
    \definefontsynonym [SansCaps]       [file:FiraSans-Regular.otf]       [features={default,smallcaps}]
  \stoptypescript

  \starttypescript [mono] [fira]
    \setups[font:fallback:mono]
    \definefontsynonym [Mono]     [file:FiraMono-Medium.otf] [features=default]
    \definefontsynonym [MonoBold] [file:FiraMono-Bold.otf]   [features=default]
  \stoptypescript

  \starttypescript [math] [fira]
    \definefontsynonym [MathRoman] [file:Fira-Math.otf] [features=mathextra]
  \stoptypescript

  \starttypescript [fira]
    \definetypeface [\typescriptone] [rm] [serif] [modern] [default]
    \definetypeface [\typescriptone] [ss] [sans]  [fira]   [default]
    \definetypeface [\typescriptone] [tt] [mono]  [fira]   [default]
    \definetypeface [\typescriptone] [mm] [math]  [fira]   [default]
    \quittypescriptscanning
  \stoptypescript

\stoptypescriptcollection

\setupbodyfont[fira,sans]

\starttext

\input knuth

\startformula
  R_{\mu\nu} - \frac{1}{2} R g_{\mu\nu} + \Lambda g_{\mu\nu} = \frac{8 \pi G}{c^4} T_{\mu\nu}
\stopformula

\starttyping
#include <stdio.h>

int main() {
    printf("Hello World!\n");
}
\stoptyping

\stoptext

Related Solutions

[Tex/LaTex] How to use OpenType fonts with plain-LuaTeX

Let me add to the confusion a bit: there are actually two formats for running Plain with LuaTeX! One of them is the format that gets called when you run the command luatex from e.g. TeX Live; egreg already posted instructions for it in his answer.

There exists, however, another format called luatex-plain. Since it comes with the font loader built in, it has the advantage of being able to use OpenType fonts without additional packages. Here’s a demo (you’ll need the free Minion Pro fonts from Adobe for the second part):

\font\iwonaregular   =file:Iwona-Regular    at 12pt
\font\iwonaitalic    =file:Iwona-Italic     at 12pt
\font\iwonabold      =file:Iwona-Bold       at 12pt
\font\iwonabolditalic=file:Iwona-BoldItalic at 12pt

{\iwonaregular     foo}\par
{\iwonaitalic      bar}\par
{\iwonabold        baz}\par
{\iwonabolditalic  xyzzy}\par

\font\minionproliningfigures =file:MinionPro_Regular         at 12pt
\font\minionprotextfigures   =file:MinionPro_Regular:+onum;  at 12pt
\font\minionprosmallcaps     =file:MinionPro_Regular:+smcp;  at 12pt

{\minionproliningfigures  0123456789abcdef}\par
{\minionprotextfigures    0123456789abcdef}\par
{\minionprosmallcaps      0123456789abcdef}\par %% implicit +onum!

\bye

font definition demo

For more complicated examples see the test file.

luatex-plain is distributed with ConTeXt and available through TeX Live in the directory texmf-dist/tex/generic/context/luatex/. (Pro Tip: build the format and then symlink the luatex binary to luatex-plain, so you don’t have to specify the --fmt parameter.)

[Tex/LaTex] More Math Fonts in ConTeXt

Here is a complete example on how to use Euler.

Download Euler OTF from Github
Move the font somewhere in your $TEXMF/fonts/opentype tree. To see the list of folders that ConTeXt searches, run:
```
mtxrun --expand-var=TEXMF
```
or
```
mtxrun --expand-var=TEXMFHOME
```
Update the font database by running
```
mtxrun --script font --reload --force
```
Check that ConTeXt can find the fonts:
```
mtxrun --script fonts  --list --pattern=euler --all
```
(you should see euler.otf in the list).

Compile the following example file (this needs ConTeXt version from October, 2013 or later).

\usetypescriptfile[euler]

\definetypeface[mainface][rm][serif][palatino]         [default]
\definetypeface[mainface][ss][sans] [helvetica]        [default] [rscale=auto]
\definetypeface[mainface][mm][math] [pagellaovereuler] [default] [rscale=auto]

\setupbodyfont[mainface,12pt]

\appendtoks \rm \to \everymathematics
\setupmathematics
  [lcgreek=normal, ucgreek=normal]

\starttext

\startformula
   {\Bbb P}(x) = \sum_{i=1}^n α_i x^i
\stopformula

\stoptext

I get the following output:

enter image description here

Note that Euler opentype font is not complete. The pagellaovereuler typescript loads Pagella as a fallback font, so the missing symbols (like the blackboard bold P in the above example) are taken from Pagella.

Best Answer

Related Solutions

[Tex/LaTex] How to use OpenType fonts with plain-LuaTeX

[Tex/LaTex] More Math Fonts in ConTeXt

Related Question