[comp.text.tex] Using invisible fonts in slitex

robert@eb10.eb.ele.tue.nl (Robert Huis in 't Veld ) (09/03/90)

Hi folks,

Recently, I started using the EMTEX 3.0 package.
In general the program runs beautifully. 
However, I encountered a problem  that I wishes to present to you. 
The problem is related to the use of fonts, and if I'm not totally
mistaken it is not only restricted to EMTEX.

	If one wishes to make overlays with slitex and one uses
	the \invisible command an error-message occurrs while previewing
	or printing the slides. This error-message is about slitex not being 
	able to find the invisible fonts. Since I didn 't generate these fonts
	I find the error message understandable. One way of solving the problem
	is by generating the fonts, but I find this an unsatisfactorary
	solution. The invisible .fmt fonts should be sufficient since they 
	contain the size information of the printer, which is all that is
	needed to print the "invisible characters". Can anyone tell me how
	the latter solution can be  implemented.


Robert Huis in 't Veld   | Phone: +31-40-473368, Fax. +31-40-448375
Eindhoven University of Technology, Depr. of Electr. Eng. (EB/EH 10.35)
P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Email: robert@eb.ele.tue.nl

dhosek@sif.claremont.edu (Hosek, Donald A.) (09/04/90)

In article <583@eba.eb.ele.tue.nl>, robert@eb10.eb.ele.tue.nl (Robert Huis in 't Veld ) writes...
>Recently, I started using the EMTEX 3.0 package.
>In general the program runs beautifully. 
>However, I encountered a problem  that I wishes to present to you. 
>The problem is related to the use of fonts, and if I'm not totally
>mistaken it is not only restricted to EMTEX.

>	If one wishes to make overlays with slitex and one uses
>	the \invisible command an error-message occurrs while previewing
>	or printing the slides. This error-message is about slitex not being 
>	able to find the invisible fonts. Since I didn 't generate these fonts
>	I find the error message understandable. One way of solving the problem
>	is by generating the fonts, but I find this an unsatisfactorary
>	solution. The invisible .fmt fonts should be sufficient since they 
>	contain the size information of the printer, which is all that is
>	needed to print the "invisible characters". Can anyone tell me how
>	the latter solution can be  implemented.

Generate the fonts. In PK format, they take up maybe 512 bytes
each, maybe a little more (I don't know since on the disk where
we keep our TeX fonts, files are allocated 5 512byte blocks at a
time).

The width information in the FMT file is available only to TeX,
not to the drivers; the only way for the drivers to handle the
solution you would want is to either (a) have the driver insert
blank space for all missing characters (which is a reasonable
solution, but I wouldn't want a driver doing this without
warnings and I wouldn't want to get warnings about every
invisible font I use) or (b) give the driver an auxiliary file
listing all the invisible fonts so it knows to read the TFM data
and just leave space for those fonts (and yes, reading the TFM
files would be necessary to avoid having PKs since that
information is not in the DVI file).

From an implementor's standpoint, the best solution is to simply
have PK files with empty rasters; yes, it takes up a bit more
space, but there are certain pieces of code in the driver that
this will encourage (the most notable of which is detection of a
character with an empty raster. The Chess fonts on
ymir.claremont.edu, for example, have a single character which is
an empty glyph which causes grief for more than one driver that
I've had experience with (the only one that comes to mind off
hand is dvidis which may or may not have been fixed in the
intervening time since I last used it)).

-dh

---
Don Hosek                       TeX, LaTeX, and Metafont support, consulting 
dhosek@ymir.claremont.edu       installation and production work. 
dhosek@ymir.bitnet              Free Estimates.
uunet!jarthur!ymir              Phone: 714-625-0147
                                finger dhosek@ymir.claremont.edu for more info

eln272v@monu1.cc.monash.oz ( r lang) (09/05/90)

In article <583@eba.eb.ele.tue.nl>, robert@eb10.eb.ele.tue.nl (Robert Huis in 't Veld ) writes:
> Recently, I started using the EMTEX 3.0 package.
> This error-message is about slitex not being able to find the 
> invisible fonts. 

Refer to the dvidrv.eng document file in emTeX.
This contains information about font substitution files.
You will need a /ps (font substitution file) command in your
configuration file (.cnf).
The following line in a font substitution file will replace characters
by a white space.  This is what you want for invisible characters.

i*  ->  * /w  % invisible, white

This will work with all emTeX drivers, so you don't need separate
invisible fonts.  If you are using a non emTeX driver (like me), 
you will probably need to create the invisible pk font files.  
See the mfjob program in emTeX.  I have written a job file to
create the missing SliTeX fonts for hplaser, which has the same
mode def as one I found for imagen, which I believe is also used
for the Apple LaserWriter.  I am currently using emTeX's hplaser 
fonts with dvips and an Apple LaserWriter.


-- 
Russell Lang   Email: rjl@monu1.cc.monash.edu.au   Phone: (03) 565 3460
Department of Electrical and Computer Systems Engineering
Monash University, Australia

tim@maths.tcd.ie (Timothy Murphy) (09/05/90)

On the subject of SliTeX,
could someone please tell me where one can get
the special transparencies mentioned in the LaTeX manual (p 133):

"These pages are called *color layers*.
Copying each of them onto a special sheet
that produces a transparency of the appropriate colour
(such sheets are commercially available in an assortment of colours)
and laying the three transparencies atop one another
produces the desired three-colour slide."

I've asked in Dublin about these sheets,
and none of the stationers has ever heard of them.


Timothy Murphy  

e-mail: tim@maths.tcd.ie
tel: +353-1-772941 x 1507
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

-- 

Timothy Murphy  

e-mail: tim@maths.tcd.ie

collberg@dna.lth.se (Christian S. Collberg) (09/05/90)

In article <1990Sep5.012050.14304@maths.tcd.ie> tim@maths.tcd.ie (Timothy Murphy) writes:
>could someone please tell me where one can get
>the special transparencies mentioned in the LaTeX manual (p 133):
>
>Timothy Murphy  
>
>e-mail: tim@maths.tcd.ie

    Visualon, Inc.
    3044 Payne Ave.
    Cleveland, Ohio 44114

    (216)566-0506
    1-800-321-3860

I bought some sheets last time I visited CMU but haven't gotten round to
try them out yet. 

Chris Collberg
collberg@dna.lth.se
    

ken@csis.dit.csiro.au (Ken Yap) (09/06/90)

In article <8258@jarthur.Claremont.EDU>:
>In article <583@eba.eb.ele.tue.nl>, robert@eb10.eb.ele.tue.nl (Robert Huis in 't Veld ) writes...
>>	If one wishes to make overlays with slitex and one uses
>>	the \invisible command an error-message occurrs while previewing
>>	or printing the slides. This error-message is about slitex not being 
>>	able to find the invisible fonts. Since I didn 't generate these fonts
>>	I find the error message understandable. One way of solving the problem
>>	is by generating the fonts, but I find this an unsatisfactorary
>>	solution. The invisible .fmt fonts should be sufficient since they 
>>	contain the size information of the printer, which is all that is
>>	needed to print the "invisible characters". Can anyone tell me how
>>	the latter solution can be  implemented.
>
>Generate the fonts. In PK format, they take up maybe 512 bytes
>each, maybe a little more (I don't know since on the disk where
>we keep our TeX fonts, files are allocated 5 512byte blocks at a
>time).

However this problem does not occur only with PK format fonts. Recently
I hacked up a quick and dirty SliTeX that uses PS fonts (who worries
about pixel rounding at 24pt) for OzTeX. Now if the driver knew that
some PS fonts are supposed to be invisible (by consulting a
configuration file or something) then there'd be no problem. If I'm
mistaken and the driver in OzTeX can already do this, let me know.

No, don't ask me for the macros, I still have to find a bit of spare
time to get the macros to use the PS bullet for items instead of the
cmsy bullet. And other minor things.

mattes@azu.informatik.uni-stuttgart.de (Eberhard Mattes) (09/06/90)

>	If one wishes to make overlays with slitex and one uses
>	the \invisible command an error-message occurrs while previewing
>	or printing the slides. This error-message is about slitex not being 
>	able to find the invisible fonts. Since I didn 't generate these fonts
>	I find the error message understandable. One way of solving the problem
>	is by generating the fonts, but I find this an unsatisfactorary
>	solution. The invisible .fmt fonts should be sufficient since they 
>	contain the size information of the printer, which is all that is
>	needed to print the "invisible characters". Can anyone tell me how
>	the latter solution can be  implemented.

If you're using the emTeX drivers, you need only the TFM files
for the *visible* SliTeX fonts. The invisible fonts can be
mapped to the visible fonts made invisible by using the drivers
with a font substitution file containing the line
    i* -> * /w
(see dvidrv.doc). [Unfortunately, you cannot use other fonts
starting with an `i'.] The newest emTeX release (20-Aug-1990)
contains a MFjob job file for creating the visible
SliTeX fonts. (Not yet available from terminator.cc.umich.edu,
but it is available from rusmv1.rus.uni-stuttgart.de.)

--
       Eberhard Mattes   (mattes@azu.informatik.uni-stuttgart.de)