LyX, LaTeX, PS, PDF

[Tom Buskey]

bscott at ntisys.com said:
>On Sun, 27 Oct 2002, at 5:59pm, tom at buskey.name wrote:
>> (not being a LyX user, but a LaTeX user) The default font for TeX is
>> Computer Modern as designed by Knuth in Metafont.  For awhile, it was hard
>> to use the postscript fonts instead of the CM fonts.
> 
>  Hmmmm.  [seaches some man pages]  Okay, so if I understand all this:
>
>  TeX is a powerful markup language that can produce a variety of nice
>outputs.  From some brief encounters I just had with it, the syntax is (or,
>at least, can be) complex and low-level.

It's a programming language designed to format text.  For you doubters, 
someone once wrote the BASIC game 'animal' in TeX (or LaTeX).

>  LaTeX is a set of macros for TeX.  LaTeX serves a function similar to that
>which the C standard library serves for the C language itself.  You don't
>have to use them, but they make like a lot easier if you do.

Like the .me and .mm macros for troff only much more.

>  Metafont is used to turn logical text and font specifications (from
>TeX/LaTeX source files) into rendered fonts (as seen on paper or screen).

Metafont creates fonts for use with TeX.

>  TeX and/or Metafont don't always do the Right Thing for PostScript because
>they pre-date PostScript becoming the de facto standard for printing and
>typesetting.

Yep.  Or maybe in parallel.  The CM fonts came out after '87.  Maybe 
'89-'90?


>  In particular, TeX defaults to a font called "Computer Modern"  that is
>not available in your typical PostScript implementation.  So, when rendering
>TeX to PostScript, Metafont is called into play to convert the "Computer
>Modern" vector font to a fixed bitmap font.  This leads to font aliasing
>problems (huge slow bitmap fonts, or tiny ugly aliased bitmap fonts).

Not exactly.  TeX produces a DVI (DeVice Independant) file.  Then a DVI 
renderer(?) converts the DVI file to a device using the fonts usually 
produced by Metafont.  Today you'd typically use dvi2ps and 
ghostscript, but I've used dvi2tty, dvi2pcl, dvi2epson, dvi2ega, and 
xdvi.

I used to run LaTeX on my DOS system, preview it with zdvi (Zenith 
Z100, *not* PC compatible).  Then I'd upload the DVI file to a VMS 
system, run dvi2ps on it & print to a postscript printer.

>  Telling LyX to use "Times" instead means that the TeX/Metafont chain can
>simply tell PostScript "use the 'Times' font you know and love" instead of
>having to do ugly conversions with bitmap fonts.

Yep.  It took a long time to get TeX do deal with non metafont fonts.

>  Is that about right?
>

Yep.  Though I'll admit I've never dealt with non CM fonts and TeX.  
Nowadays the only time I really worry about layout and fonts, etc are 
on my resume.  Most of my documents are email where fonts and layouts 
are not as important.

When I did worry about that stuff, LaTeX was great.  I had a doc with 
30+ equations each with a seperate biblographic entry and footnote.  
LaTeX did the layout, organization, and worried about numbering things. 
I focused on the content.  My secretary, who usually retyped everything 
into Word4win 2.0 before editing, had to resort to marking up my 
document with a pen.  She was a great editor.  Word4win couldn't touch 
the equations to say nothing of the organization.

I was later involved in a conversion of a 300 page LaTeX doc to word.  
Lots of postscript graphics, tons of high level math (it was a manual 
for a computational fluid dynamics program).  They wanted to use the 
windows help system & that needed word docs.

It was about 2MB of .tex file and many more .eps graphics files.   We
had macs to run word on.  Word 4, system 7, 100MB hard drives and 68k
cpus.  The files quickly balloned to over 30MB and the indexing and
references became a nightmare.  We went from a mac SE -> LC II -> Quadra
800 -> a mac emulator on a sparc 10 that only ran word & excel.

One of our programmers whipped up a previewer to display & typeset the 
manual on the fly in about a week.  I think the conversion to word took 
over a month if it was done at all.  And it wasn't as good or as fast 
to display in the end.


-- 
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Tom Buskey