[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: design size in DVI
Thanks to Berthold and Nelson for replies to my
> (2) Does/should anybody or anything currently pay
> the design size entry?
I see it essentially as Berthold does. Some extra
-- DVIPS will complain if a font's "design_size" in
the DVI does not coincide with design size in the
TFM; many other drivers ignore it entirely.
-- The size of the print is entirely determined by
"at_size", and is directly proportional to it. More
precisely, a character's box width on paper is:
"TFM width" * "at_size" * mag/1000
Similarly for all other dimensions dictated by the
-- DVI drivers ignore "design_size" in the DVI and in
the TFM or VF, except for the mentioned coherence
check; ie drivers at most use "design_size" as an
-- TeX invariably copies "design_size" from TFM to
DVI, which is the same behavior as for the checksum.
-- TeX however also uses "design_size" when the
following syntax is met:
and it responds by setting the "at_size" in the DVI
equal to the "design_size" in "myfont.tfm". It
similarly uses "design_size" in interpreting
\font\fnt=myfont scaled <mils>
But TeX does *not* use "design_size" in interpreting
\font\fnt=myfont at 14pt
indeed it simply sets the "at_size" in the DVI to
IN SUMMARY: "design_size" is used in a way that
influences what appears on paper/screen only by TeX,
which, merely for user syntax convenience,
sometimes uses it as a default "at_size" in
interpreting font definitions. If the use of the
keyword "at" in TeX font definitions were
*obligatory* (thus "scaled" would be forbidden) then
"design_size" would be nothing more nor less than an
extra checksum, something that Carl Berry and
Berthold Horn badly want.
Near miss. Too bad!