ligatures?

ligatures?

[Adam Lindsay]

TeXnicians,

Once again, I'll stick my neck out showing my pure TeX ignorance.

Are there ConTeXt commands for adding ligatures to the usual set (ff, fi,
etc.)? Where in the chain are these characters (f + i) grouped and
associated with the 'fi' character to be output?

I'd like to be able to take advantage of some extended ligatures with my
pro fonts, but it seems that if users have to enter the ligatures as
\Thligature or whatever, they would be of very limited use.

thanks in advance,
adam

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Adam T. Lindsay                      atl@comp.lancs.ac.uk
 Computing Dept, Lancaster University   +44(0)1524/594.537
 Lancaster, LA1 4YR, UK             Fax:+44(0)1524/593.608
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: ligatures?

[Bruce D'Arcus]

On Monday, May 12, 2003, at 10:28  AM, Adam Lindsay wrote:

> Are there ConTeXt commands for adding ligatures to the usual set (ff, 
> fi,
> etc.)? Where in the chain are these characters (f + i) grouped and
> associated with the 'fi' character to be output?

IIRC, look in the encoding files; in other words, at the level of TeX 
itself.

To add ligs, though, you need to use slots.  Because of the 256 
character limit, this means you have to throw out other glyphs to get 
the extra ligs AFAIK.

Bruce

Re: ligatures?

[Bill McClain]

On Mon, 12 May 2003 10:57:52 -0400
"Bruce D'Arcus" <bdarcus@fastmail.fm> wrote:

> To add ligs, though, you need to use slots.  Because of the 256 
> character limit, this means you have to throw out other glyphs to get 
> the extra ligs AFAIK.

I wonder: the vf files define ligatures also; run vftovp on one and look
at the LIG entries in the LIGTABLE section. Could this be used to add
arbitrary number of new ligatures, or convenient coding for some glyphs?
Hoenig has examples of this sort of thing in _TeX Unbound_.

I've wanted to experiment with virtual fonts for a while, but am daunted
by fontinst. 

-Bill
-- 
Sattre Press                                      Pagan Papers
http://sattre-press.com/                    by Kenneth Grahame
info@sattre-press.com              http://pp.sattre-press.com/ 

Re: ligatures?

[Bruce D'Arcus]

On Monday, May 12, 2003, at 11:01  AM, Bill McClain wrote:

> I've wanted to experiment with virtual fonts for a while, but am 
> daunted
> by fontinst.

Here's a really good new tutorial:

	http://lehman.virtualave.net/files/ltxfonts.pdf

Bruce

Dumb newbie question about UTF-8 support

[Edmund Lian]

Hi All,

I'm a newbie experimenting with TeX/ConTeXt as a cross-platform MS 
Word/Quark/InDesign/etc. substitute.

I like what I've seen so far, so I moved on to exploring how well it 
would support a multilingual situation. And this is where I started to 
get confused...

I need to be able to use both Traditional and Simplified Chinese, 
English and perhaps one or two other languages. The problem with Chinese 
is that there are several different encoding standards--Big5, GB, HZ, 
etc. I'm trying to avoid the mess involved in moving documents between 
Big5 and GB by going to UTF-8 as a standard.

Despite all my Googling however, I still haven't been able to establish 
a suitable tool chain to process these documents using TeX/ConTeXt... 
some of my initial points of confusion are:

1. TeX. Apparently it is not UTF-8 capable, hence Omega and NTS. 
However, I see Unicode extensions for LaTeX. How is this possible, and 
what is the analogous situation for ConTeXt?

2. ConTeXt. I see passing references to some kind of UTF-8 extension, 
but cannot find documentation on it. mchinese.pdf also mentions this in 
passing. Is it possible to feed UTF-8 documents to ConTeXt?

3. Font installation. mchinese.pdf describes how to install Chinese 
fonts, but the tools used are not available in some of the environments 
that I've been using (Mac OS X, Debian/GNU Linux, etc.) I did come 
across ttf2tex, but there's no mention of this in mchinese.pdf. Where 
can I find more current instructions for installing fonts for ConTeXt?


Finally, I wonder if anybody else finds the pragma-ade.nl site very hard 
to use/navigate because of the heavy use of PDFs? Some of the 
in-document links that call up other PDFs are broken. And, if the 
browser isn't set up right, it tries to download the PDF rather than 
opening it in-place. I can't help thinking that a more HTML-oriented 
site would actually improve navigability and utility...

...Edmund.

Re: ligatures?

[Patrick Gundlach]

"Adam Lindsay" <atl@comp.lancs.ac.uk> writes:

> I'd like to be able to take advantage of some extended ligatures with my
> pro fonts, but it seems that if users have to enter the ligatures as
> \Thligature or whatever, they would be of very limited use.

Adam,

make use of the "Virtual Fonts" feature in TeX and the backends. How
did you install your fonts? You should have some .vf files for your
fonts and you can access the contents of them with vftovp (convert
back with vptovf) and just add ligature information. See Knuth's "More
fun for Grand Wizards: Virtual Fonts" available on ctan or in Knuth's
book "Digital typography". (Hope I got the title of the article
right.) Virtual Fonts are real fun to play with! It is (imo) one of
the best reason to use TeX :) It is completely transparent to the
users, no need to say \Thligature or so.


Patrick

Re: Re: ligatures?

[Bruce D'Arcus]

On Monday, May 12, 2003, at 11:03  AM, Patrick Gundlach wrote:

> make use of the "Virtual Fonts" feature in TeX and the backends. How
> did you install your fonts? You should have some .vf files for your
> fonts and you can access the contents of them with vftovp (convert
> back with vptovf) and just add ligature information.

The strategy he used does not use virtual fonts.  It involved running 
afm2tfm (via texfont) on the afms to extract the glyphs using different 
encodings.  Conceptually this is pretty straightforward.  I'm not sure 
(because I've never done it) what would be involved in extending this 
installer to support adding ligs via vfs...

Bruce

Re: ligatures?

[Patrick Gundlach]

"Bruce D'Arcus" <bdarcus@fastmail.fm> writes:

>> make use of the "Virtual Fonts" feature in TeX and the backends. How
>> did you install your fonts? You should have some .vf files for your
>> fonts and you can access the contents of them with vftovp (convert
>> back with vptovf) and just add ligature information.
>
> The strategy he used does not use virtual fonts.  

Who is "he" in this case? Adam? 

> It involved running afm2tfm (via texfont) on the afms to extract the
> glyphs using different encodings. 

But afm2tfm gives you the vf's! And how can you reencode a font
without vf's? Are you doing this in the mapfile?

> Conceptually this is pretty
> straightforward. I'm not sure (because I've never done it) what
> would be involved in extending this installer to support adding ligs
> via vfs...

Just take the fi as an example.

Patrick

Re: Re: ligatures?

[Bruce D'Arcus]

On Monday, May 12, 2003, at 05:27  PM, Patrick Gundlach wrote:

>> The strategy he used does not use virtual fonts.
>
> Who is "he" in this case? Adam?

Yes.  And me too.

>> It involved running afm2tfm (via texfont) on the afms to extract the
>> glyphs using different encodings.
>
> But afm2tfm gives you the vf's! And how can you reencode a font
> without vf's? Are you doing this in the mapfile?

OK, I don't fully understand virtual fonts, but let's take an example:

You have a font with 1,000 + glyphs (an OpenType Pro font).  You take 
texnansi as your base encoding, and create a variant encoding that 
replaces regular figures with old-style.  You run afm2tfm on the afms 
using this variant encoding, and it creates a tfm with all of the 
necessary metric information.

When you typeset, you tell it to use texnansi so that TeX uses the 
old-style figures.  No need for virtual fonts (as it was explained to 
me, you will put TeX into infinite loop if you actually refer to the 
vfs in this case, but I don't understand exactly why; I think because 
the vf refers to the tfm, which refers back to the vf.).

Bruec

Re: Re: ligatures?

[Adam Lindsay]

Patrick, Bruce, Bill,

Thanks a lot for the excellent suggestions. I had completely avoided
Virtual Fonts before (even when making "new" math fonts), because I
thought it would be too much of a big topic to tackle (more that it would
be too interesting, rather than too difficult :).

After this enthusiastic response, however, I'll be giving the topic a
closer look. Thanks for the Lehman link, Bruce.


So, am I right in concluding that ligatures are *only* handled by the
output routine? There's no way of using ConTeXt to map my normal text
input ('i' followed by 'j') to the already-defined \ijligature?

Cheers,
adam

Patrick Gundlach said this at Mon, 12 May 2003 17:03:01 +0200:

>"Adam Lindsay" <atl@comp.lancs.ac.uk> writes:
>
>> I'd like to be able to take advantage of some extended ligatures with my
>> pro fonts, but it seems that if users have to enter the ligatures as
>> \Thligature or whatever, they would be of very limited use.
>
>Adam,
>
>make use of the "Virtual Fonts" feature in TeX and the backends. How
>did you install your fonts? You should have some .vf files for your
>fonts and you can access the contents of them with vftovp (convert
>back with vptovf) and just add ligature information. See Knuth's "More
>fun for Grand Wizards: Virtual Fonts" available on ctan or in Knuth's
>book "Digital typography". (Hope I got the title of the article
>right.) Virtual Fonts are real fun to play with! It is (imo) one of
>the best reason to use TeX :) It is completely transparent to the
>users, no need to say \Thligature or so.
>
>
>Patrick
>_______________________________________________
>ntg-context mailing list
>ntg-context@ntg.nl
>http://www.ntg.nl/mailman/listinfo/ntg-context

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Adam T. Lindsay                      atl@comp.lancs.ac.uk
 Computing Dept, Lancaster University   +44(0)1524/594.537
 Lancaster, LA1 4YR, UK             Fax:+44(0)1524/593.608
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: Re: ligatures?

[Bruce D'Arcus]

If you want to get completely out of control (and I don't recommend 
this unless you really need the functionality):

You can also use the ligature mechanism to access alternate glyphs.  
For example, you could set up the fonts so that *Z gives you the swash 
Z.

The technique (though using Omega) is outlined here:

http://www.tau.ac.il/~stoledo/Pubs/ps3.ps

Bruce

Re: ligatures?

[Patrick Gundlach]

"Adam Lindsay" <atl@comp.lancs.ac.uk> writes:

Hello Adam,

I am not a TeX expert, but I try to give an answer. Please anybody
out there correct me. 

> So, am I right in concluding that ligatures are *only* handled by the
> output routine? 

The ligatures defined by the font are handled by the paragraph
breaking routine. Deep down inside the lion. The "output routine"
(OTR) is something different.

> There's no way of using ConTeXt to map my normal text input ('i'
> followed by 'j') to the already-defined \ijligature?

In order to parse the text so that ij is mapped to \ijligature, you
probably have to make the "i" active and check if the next char is
"j" and if yes, replace it with \ijligature. Don't think about it.


Patrick