Re: [Groff] Device-independence of intermediate output

[Bernd Warken]

On Thu, Jan 31, 2002 at 09:11:57AM -0000, Ted Harding wrote:
> On 31-Jan-02 Bernd Warken wrote:
> > The "Troff User's Manual" [CSTR #54, ch. 22] reads:
> > 
> >   Troff produces its output in a language that is independent of any
> >   specific output device, except that the numbers in it have been
> >   computed on the basis of the resolution of the device, and the
> >   sizes, fonts, and characters that that cevice can print.
> >   Nevertheless it is quite possible to interpret that output on a
> >   different device, within the latter's capabilities.
> > 
> > The groff intermediate output language does not support this feature -
> > although it is a base feature of device independent troff, on which
> > groff was originally built.
> 
> So I'm wondering what Bernd means when he says that the
> "groff intermediate output language does not support this
> feature"
> 
> There already is an element in the groff/troff output
> language which allows this:
>
>   x r n h v
>
The ancient Postscript device (called post) had a resolution of 720.
To run this on the modern ps device with resolution 72000 you must provide
a scaling factor of 100.  With that scaling facility, it would be possible
to process an ancient intermediate "post" output file without changing the 
file.   This is wanted by the "sacred roff bible"  CSTR#54/#97.

> It would not be the first time that the original Sacred Texts
> have been found to be not quite comprehensive.

I'm not religious, but I wonder why the German theologists changed the
Fifth Commandment from "You shall not kill" into "you shall not murder".
Maybe the "Sacred Texts" contain some wisdom that is uncomfortable to some
guys.

The scaling feature is transparent to any existing groff code.  It just
makes available existing ancient code and code written on the base of the
documentation. 

I will implement this feature anyway.  But I would like to discuss the
subject with people who are willing to understand it.
Not understanding a concept is no reason for blocking it.

Bernd