[comp.text.tex] cmex10 font, LaTeX line fonts scaling problem

bed_gdg@SHSU.BITNET ("George D. Greenwade") (03/04/91)

Michael Barr <barr@triples.Math.McGill.CA> commented while I was away that
he attempted to make a post to INFO-TeX which somehow got misdirected.  He
has posted this to TeXhax already, but I thought it would be worthwhile to
pass along to our readership.  Apologies to all for any misdirected mail.
Should this ever occur with a post you have made, please bring it to my
attention so I can attempt to trace back what problem occurred in
transmission.
 
George
--------- forwarded from "Michael Barr" <barr@triples.Math.McGill.CA> ---------
font scaling in LaTeX
 
I don't recall this point being made previously about the LaTeX fonts at
other than 10pt.  I usually use 12pt (failing eyesight, I guess) and
have lately been using 20pt to prepare some slides, lacking the slitex
fonts.  I was quite surprised to discover that two fonts, at least, were
not scaled in the latex macro \xxpt.  I was astonished to discover that
the same two fonts were not scalded at 12pt and, once you know that, the
effect becomes obvious.  They are the cmex10 and the line10 (actually, I
should include the linew10 and the two circle fonts but I never use
them).  The failure to scale the cmex10 means that the large operators
are only a bit larger than the normal sized one and the failure to scale
the line fonts means that arrows drawn with them have the arrowheads
rather emacitated looking and badly placed besides (not at the ends of
the arrows).  The remedy for cmex10 is to add
 
\font\twlex=cmex10 scaled\magstep1
\def\@xiipt{\textfont\thr@@\twlex \scriptfont\thr@@\tenex
\scriptscriptfont\thr@@\tenex}
 
to the art12.sty (and the other 12.sty files).  For the line10, I have
added
 
\font \@linefnt=line10 scaled \magstep1
 
but this disables the \thicklines macro.  A somewhat more subtle
approach is needed to avoid that.
 
An art20.sty file I have made up includes the lines:
 
\font\twtyex=cmex10 scaled\magstep4
\font\frtnex=cmex10 scaled\magstep2
\def\@xxpt{\textfont\thr@@\twtyex \scriptfont\thr@@\frtnex
\scriptscriptfont\thr@@\tenex}
\font \@linefnt=line10 scaled \magstep4
 
Michael Barr

barr@TRIPLES.MATH.MCGILL.CA (Michael Barr) (03/05/91)

I partly agree, but not totally.  If I understand what metafont does, if
you do something using \magstep1 throughout and then reduce it to 83%,
not much different from 85%, you should get exactly the same result
as you get at \magstep0 (except the resolution ought to be better).
If this understanding is not correct, I would like to know what is correct.
As for use at full size, it may be that the \magstephalf is better, but
that's a different matter.  At 20pt, quite reasonable for slides, the
size is much more important than the weight of the font.
 
Actually, I am thinking of printing something at 14pt to reduce to 70%
and print sideways just for the increased resolution, so I really want
to know the answer to my question above.
 
Michael Barr

nlbeck@UCSD.EDU (Nathaniel Beck) (03/06/91)

 

jg@prg.ox.ac.uk (Jeremy Gibbons) (03/06/91)

barr@TRIPLES.MATH.MCGILL.CA (Michael Barr) asks:

> If I understand what metafont does, if
> you do something using \magstep1 throughout and then reduce it to 83%,
> not much different from 85%, you should get exactly the same result
> as you get at \magstep0 (except the resolution ought to be better).
> If this understanding is not correct, I would like to know what is correct.

I've often wondered about this. Perhaps a more direct question is, do I get
the same results making a font for a 600dpi device as I do making a 300dpi
font at mag=2? (In particular, does the rounding happen the same way?)
Presumably, the values of blacker, fillin etc in the 600dpi mode_def would
have to be twice those in the 300dpi mode_def? (Aside: they are
undimensioned units---blacker=.55, for example---so presumably are in
numbers of pixels?)

Is the question `Do I get the same results using mag as I do by
multiplying all the dimensions directly by that amount?' equivalent? The
Sauter scripts do the latter for the fonts which are interpolated from only
one master (eg cmssq); is a 16pt cmssq (formed by multiplying all the
dimensions in cmssq8 by 2) the same as cmssq8 scaled 2000?

If so, what did Karl Berry mean when he wrote

> I've
> looked at some of the fonts, and they're pretty good.
> (Better than the magnified versions!)

(in the file READ_ME.unix with the Sauter scripts)? Did he just mean that a
cmr14 interpolated from cmr12 and cmr17 was better than either one scaled?
(Karl, are you reading this?)

Jeremy

*-----------------------------------------------------------------------*
|  Jeremy Gibbons (jg@uk.ac.oxford.prg)   Funky Monkey Multimedia Corp  |
*-----------------------------------------------------------------------*

nlbeck@UCSD.EDU (Nathaniel Beck) (03/07/91)

I fear that info-tex is getting out of hand. I don;t know what the
problem is - I was replying (to the list) saying that I didn't see
any problem. Now my reply to the list appears to be circulated to
everyone.
 
But the short answer to your question is that I see now problem.
 
Regards
 
Neal
 

mackay@CS.WASHINGTON.EDU (Pierre MacKay) (03/07/91)

The Middle East Studies Association Bulletin uses \magstep1 followed
by reduction for exactly the reason that Michael Barr gives.  A few
issues were produced several years ago on one of the three Alphatypes
that ran TeX in North America, but when that broke, the Laser-Writer
became the final output device.  It works fine.  This is what global
magnification is for.  An effective resolution of 360 dpi is superior
to 300dpi by a quite surprising degree.  I think it is partly because
some of the fuzz at the edge of the dots gets reduced by the camera to
the point that disappears in the printing process.
 
At low resolutions there may be some slight non-linear effects
attendant on the use of magsteps in METAFONT, which will be understood
by anyone who reads the chapter Discreteness and Discretion in the
METAFONTbook, but they should not seriously change the appearance of
the page.  The would be very unlikely to distort the proportions of
cmex in any noticeable way,
 
 
 
 
Email concerned with UnixTeX distribution software should be sent primarily
to:     elisabet@max.u.washington.edu           Elizabeth Tachikawa
otherwise to:  mackay@cs.washington.edu         Pierre A. MacKay
Smail:  Northwest Computing Support Center      TUG Site Coordinator for
        Thomson Hall, Mail Stop DR-10           Unix-flavored TeX
        University of Washington
        Seattle, WA 98195
        (206) 543-6259