font encoding -possible slot assignments for glyphs

["Dr.K. Kalyanasundaram" <kalyan@igcsun3.epfl.ch>]

Dear Friends:
To keep advancing in our discussions for a possible standard 
font-encoding scheme for tamil, I have now put up a gif image file 
that shows possible tamil character glyphs that can go in the
future (standard) font encoding scheme (font) for tamil. The 
URL reference is:
    http://www.geocities.com/Athens/5180/charset1.gif

At the outset let me state that, it is a preliminary version (labelled
as version 1.0) with some arbitrary slot assignments to the
choice of tamil character glyphs that I listed earlier with some
changes. In the 9th row, I have now indicated in parenthesis, 
possible inclusion of tamil numerals. These numerals are there 
in the Unicode/ISCII standard set for tamil. The present scheme 
has all the glyphs that are listed in the unicode set for tamil. 
It is the outcome of several months discussions (sometimes
very hot) that we had in these forums. So it is very much your 
scheme.

I repeat, it is a draft  (!).  There are still scope for improvements.
 I humbly request all tamil lovers to have a close and calm
look at this gif and pass on your comments - positive as well
as negative. Based on the suggestions, we can revise the
assignments and review again the revised character/glyph set.

For the benefit of those who missed earlier discussions (e.g 
those in tamil.net alone), I just summarise the key points:

a) To ensure high quality output, kerning process is kept to the
bare minimum and majority of the tamil character glyphs are 
kept as such.  Only the ikara and iikara varisai uyirmeis are 
to be typed using the modifier keys. (thus only 36 out of 256
are generated this way). Since these are right-end
modifiers there should not be problems in implementation.
Also most of the DTP packages that allow romanized/phonetic
input are "interpreted output" type. For these, high quality 
versions of the above set of uyirmeis can be stored and 
called up when necessary.

b) old style characters (for lai/Nai/nai, Ra, Naa, naa) are kept
mainly to ensure that, electronic archiving of ancient tamil 
literature in the original form in which they were first written 
is possible. We do not have to sacrifice anything for this.
In Singapore conference, many including Prof. H. Schiffman
emphasised that only if we make provisions for old  style
characters it will be possible to electronically reproduce/publish
literatures that are still in palm-leaf manuscripts. TamilNet'97
conference held recently in Singapore officially decided to 
keep these old  style characters in font encoding scheme.
No one is obliged to use them if they do not want. 
I propose that DTP packages be written in such a way that the
default option is the modern version. Old version output given
as a possible pull-down menu option.

c) grantha characters: are kept for the same reasons indicated
above under (b). The modifiers are to be used to get the ikara,
iikara, ukara, uukara varisais. Since these grantha characters
are rarely used, one can accept some medium quality output
for these grantha ones. Here again, softwares can be written
in such a way to provide high quality output required for 
commercial publishing houses.

d) four diacritical markers are included that will allow typing
tamil in the classical transliterated format, familiar and widely
used by indologists. This way we can have one single integrated,
bilingual font that allow typing tamil in tamil script and in
transliterated format (romanized with or without diacritical
markers) all at the same time!

e) space is still there to accommodate tamil numerals. 
Yes, no body uses them these days. But these are there
for reasons listed under (b) and also, most importantly, to 
have the unicode/iscii standard set for tamil as a sub-set.
If we can keep the unicode set as a sub-set of integrated font, 
it will be possible to write up a one-to-one mapping table and allow 
softwares to save tamil text files in these unicode/iscii format.
This way we can make the present scheme co-exist happily
in the unicode world and also facilitate smooth transitions
at a later date. 

I request again all tamil computing users to have a look at this
font encoding scheme and see if it has everything you would like
to see in the standardised tamil font of the 21st century.
This is rather URGENT and we need input from everyone of you.
If you do not want to flood the mailing list, please send 
your comments (positive or negative) directly to me. This way
I can have some idea on its possible acceptance by the tamil
community. I will try to summarise the emails I get to my mailbox.

with best regards,
Kalyan

PS:  My apologies to those who are in more than one mailing
list. I do not know who is which list to filter out possible duplicate
mails going to the same person.

--
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Dr. K. Kalyanasundaram,            |
Institute of Physical Chemistry,   | Tel: 41-21-693 3622 (off)
Swiss Federal Inst. of Technology  | Fax: 41-21-693 4111
CH-1015 Lausanne, Switzerland      | Email:kalyan@igcsun3.epfl.ch
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