Choosing an encoding - what are the consequences?

Choosing an encoding - what are the consequences?

[Stefan Wachter]

Hi all!

I am on the burdensome path to understanding font handling in ConText. 
Now I wonder what the consequences are with choosing certain encodings.

For example if I choose "8a" encoding (called "Adobe standard encoding"):

1. There are lots of empty slots in this encoding. What does ConText do 
if a symbol that is to be typeset is not contained in an encoding?

2. Can I ommit the 8a encoding in map files when PDF documents are 
generated (because it is the Adobe standard encoding)?

3. Somewhere I read that "texnansi" is a preferred encoding. Why?

Thanks for your attention,
--Stefan

Re: Choosing an encoding - what are the consequences?

[Adam Lindsay]

Stefan Wachter said this at Tue, 15 Feb 2005 09:38:02 +0100:

>I am on the burdensome path to understanding font handling in ConText. 
>Now I wonder what the consequences are with choosing certain encodings.

I'll give an answer based on what I understand. Mind you, I'm lucky
enough to write almost exclusively in English, where it's not an issue.

>For example if I choose "8a" encoding (called "Adobe standard encoding"):

Okay, as far as I know, ConTeXt doesn't have an 8a/Adobe encoding vector
defined yet.

>1. There are lots of empty slots in this encoding. What does ConText do 
>if a symbol that is to be typeset is not contained in an encoding?

It falls back to the enco-def encoding, where it substitutes or composes
a character from known (or expected) defaults.

>2. Can I ommit the 8a encoding in map files when PDF documents are 
>generated (because it is the Adobe standard encoding)?

Dunno. But it's worth finding out! :)

>3. Somewhere I read that "texnansi" is a preferred encoding. Why?

I think it's got the most useful (to Hans) glyphs packed in there. 
There's the secondary fact that the built-in fonts shipped with most
distributions don't include it, and Hans seems to view most pre-
fabricated TFM files with some suspicion. If you build a local TFM file
with texfont, then you know what you're getting!

But that's only my interpretation.
-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 Adam T. Lindsay, Computing Dept.     atl@comp.lancs.ac.uk
 Lancaster University, InfoLab21        +44(0)1524/510.514
 Lancaster, LA1 4WA, UK             Fax:+44(0)1524/510.492
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Re: Choosing an encoding - what are the consequences?

[Henning Hraban Ramm]

Am 15.02.2005 um 15:50 schrieb Adam Lindsay:
>> 3. Somewhere I read that "texnansi" is a preferred encoding. Why?
> I think it's got the most useful (to Hans) glyphs packed in there.

Compare texnansi and ec encodings and decide which of these fits your 
needs.
AFAIK ec has some more eastern european signs.

Grüßlis vom Hraban!
---
http://www.fiee.net/texnique/
http://contextgarden.net

Re: Choosing an encoding - what are the consequences?

[Stefan Wachter]

Adam Lindsay wrote:

 > Okay, as far as I know, ConTeXt doesn't have an 8a/Adobe encoding vector
 > defined yet.

What does it mean that ConTeXt doesn't have an 8a/Adobe encoding vector? 
Isn't it enough for ConTeXt that there is an 8a.enc file? (I am prepared 
to write the necessary typescripts myself.)

 >
 >
 >>2. Can I ommit the 8a encoding in map files when PDF documents are
 >>generated (because it is the Adobe standard encoding)?
 >
 >
 > Dunno. But it's worth finding out! :)

I installed the Adobe Helvetica fonts in 8a encoding using texfont. Then 
I removed the download instructions in the generated map files. After 
that I could generate PDF documents that are rather minimal: no fonts or 
encodings were embedded.

Yet, the results were in some way unexpected. It seems that the 8a 
encoding really isn't supported by ConTeXt. For example if I say

\setupencoding[default=8a]

and output the character \char251

then I get a "ß" in the resulting PDF. I am very astonished to receive 
that character because in 8a, T1, and texnansi encoding the glyph 
/ucircumflex is located at that slot.

Maybe this has to do with virtual fonts? I still struggle with all these 
matters.

1. The afm2tfm tool allows to set two different encodings: "-p ps-enc" 
and "-t tex-enc" whereas texfont offers only one encoding. Does texfont 
use the same encoding for the ps-enc and the tex-enc?

2. What is the meansing of the ps-enc and the tex-enc, respectively?

Can anyone help with these questions?
--Stefan

Re: Re: Choosing an encoding - what are the consequences?

[Hans Hagen]

Stefan Wachter wrote:
> Adam Lindsay wrote:
> 
>  > Okay, as far as I know, ConTeXt doesn't have an 8a/Adobe encoding vector
>  > defined yet.
> 
> What does it mean that ConTeXt doesn't have an 8a/Adobe encoding vector? 
> Isn't it enough for ConTeXt that there is an 8a.enc file? (I am prepared 
> to write the necessary typescripts myself.)

you need to write an enco-ase file then; no reason for typescripts

> Yet, the results were in some way unexpected. It seems that the 8a 
> encoding really isn't supported by ConTeXt. For example if I say
> 
> \setupencoding[default=8a]
> 
> and output the character \char251
> 
> then I get a "ß" in the resulting PDF. I am very astonished to receive 
> that character because in 8a, T1, and texnansi encoding the glyph 
> /ucircumflex is located at that slot.
> 
> Maybe this has to do with virtual fonts? I still struggle with all these 
> matters.

no, just make me an enco-ase (adobe standard encoding) file; you can use 
enco-ans as starting point

Hans

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
      tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------