# Bottom margin vs. descenders question

Reinhard Kotucha reinhard.kotucha at web.de
Sun Jun 28 02:33:12 CEST 2020

On 2020-06-27 at 06:58:16 +0100, Philip Taylor wrote:

> Hallo Reinhard Ñ
>
> > just for the record, with pdftex-based formats you can save a
> > \newdimen with
> >
> >    \hoffset = \dimexpr \hoffset - \pdfhorigin \relax
> >    \voffset = \dimexpr \voffset - \pdfvorigin \relax
> >
> > You can even save the arithmetic as well with
> >
> >    \pdfhorigin = 0pt
> >    \pdfvorigin = 0pt
> >
> > These variables are set to '1 true in' in pdftexconfig.tex, which is
> > read by {pdf,lua}tex.ini and thus go into the format files.  As far as
> > I can see they are not available in XeTeX, unfortunately.
>
> Thank you for that most interesting piece of information.Ê Not a day
> goes by when I do not ask myself how on earth Don came to make what I
> regard as the totally crazy and arbitrary decision that the page origin
> should be (1", 1").Ê It has been said, I know, that he just wanted TeX
> to "do what is right" for the simplest piece of code (e.g., "Hallo
> world\end") but that is so at variance with the rest of the philosophy
> of TeX that it strikes me as insane.Ê It is good to know that, in PdfTeX
> at least, the origin is a configuration option, but unless/until that
> feature makes its way into XeTeX I am sadly unlikely to be able to make
> use of it (other than for pure interest).

Hello Phil,
at the time Knuth wrote TeX the offset was reasonable because pages
were cut after printing.  At this time he wasn't aware of PDF files
which are supposed to be viewed on screen, hence we can't blame him.

Another point is Metafont.  Knuth assumed that all one has to do is
to create plack and white pixels.  It turned out later that people
read documents on screen where vector fonts are more appropriate.

On the other hand the concept of Metafont is largely misunderstood.
Metafont *is* is a format which supports scalable vector graphics
inherently.  The sole problem is that the PDF standard doesn't support
it.

Regards,
Reinhard

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Reinhard Kotucha                            Phone: +49-511-3373112
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