[tex-live] What do to with cm-super

[gnwiii at gmail.com]

On 6/3/06, Ralf Stubner <ralf.stubner at physik.uni-erlangen.de> wrote:
> Vladimir Volovich <vvv at vsu.ru> writes:
>
> > sure - since the LM fonts are of better quality, it is good to use
> > them whenever possible instead of the cm-super fonts.
> >
> > if their metrics for the T1 and TS1 encodings are compatible with the
> > EC fonts (which i don't know/didn't check),
>
> Unfortunately they are not compatible even for identical design size. [...]

[Very useful analysis omitted.]

> [...]  I see four possibilities:
>
> 1) The teTeX approach: No cm-super at all. Tell people to use LM
>    instead. Easy to implement, maximal space saving, but also maximal
>    problems with Type3 fonts.

Where do the Type 3 fonts come in?  Is this mostly a question of
support for  languages outside the lm domain?

> 2) The type1ec approach: Include only the 10pt design size and tell
>    people to use type1ec with option '10pt' or download not included
>    fonts. Not difficult to implement, large space saving, still many
>    problems with Type3 fonts.
>
> 3) Try to define a subset of design sizes to include, maybe based on the
>    ones used by fix-cm.sty. In addition, one could exclude all design
>    sizes of Dunhill, Fibonacci Medium/Slanted, Funny Roman/Italic and
>    probably a few more. Not easy to implement, probably one half of
>    cm-super can be excluded that way. Problems with Type3 fonts should
>    be minor, especially when fix-cm.sty is used.
>
> 4) Leave it as it is, ie include all of cm-super. Easy to implement, no
>    problems with Type3 fonts, but also no space saving at all.

5) For a really minimal distro that is still useful for generating
documentation for screen viewing, use math fonts compatible with
something from the (system default, usually some URW collection)
laserwriter 35 fonts and a tt font suitable for software documenation.
 For people who are sufficiently unhappy to invest some bandwidth and
disk, lm and cm-super are available.  A lot of time will be spent
discussing which fonts to use, but otherwise not hard to implement.

> Again, each possibility has its own set of (dis)advantages and it is a
> question of priorities which route to follow.

Unless a volunteer steps forward to actually do the hard cases (2 or 3),
"easy to implement" will carry the day.  It would be nice to have the
option of choosing between these options when installing TL.

I think option 5 has advantages for linux distros where the size of
teTeX is a bit painful, especially given that many users won't install
it, but it needs to be clear that the basic package can be updated to
something more complete (e.g., TL) without breakage.  Many people who
try TeX for program documentation are put off by cm (cmtt makes it
hard to fit program code in a line, and the fonts are anemic compared
to the fonts people are used to seeing).

> BTW, the closest one can get to a 'free lunch' is probably the usage of
> pfb2t1c and t1c2pfb, both available from CTAN:ps-type1/cm-super/debian.
> The idea behind these programs is that a Type1 font can be reencoded in
> such a way that compression is much more effective. A real life example
> from cm-super:

This makes a lot of sense, but fails the "easy to implement" test.
For the people who are in a position to implement this, disk and
bandwidth are likely not
a big issue, so (unless they are getting a salary) who ever does it is
really doing it for someone else's benefit.

More compact cm fonts should, however, be of interest to linux vendors
where supporting many languages wins over font "quality" for those
languages supported by lm.  Using pfb2t1c for a fix-cm.sty subset of
cm-super fonts as suggested in option 3 seems like a useful compromise
for a teTeX replacement.

-- 
George N. White III <aa056 at chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia