[XeTeX] Contextual Ligature Problems with OT Tamil Font Converted to AAT

[Philip TAYLOR (Webmaster, Ret'd)]

Peter Dyballa wrote:
>
> Am 19.06.2011 um 15:14 schrieb Philip TAYLOR (Webmaster, Ret'd):
>
>> Yes, but your mail will be read by others (such as myself)
>> who are unaware of either of these facts, and will then be
>> misled into believing that it should work in their platform.
>
> The term "AAT" stands for "Apple Advanced Typography". The term is also
> used in the fontspec manual. And it appears in many files of the TeX
> distribution.
>
> You shouldn't blame me or others (you not included). But look into
> Wikipedia or some other source of wisdom and information. I am also sure
> that some simple facts can be learned. Like that it's bright when it's
> day and that it's dark when it's night. (At least on Earth.) Put into
> other words: I know where AAT, ICU, and Graphite belong to or come from
> and don't spend further thinking on this, it is to me as common as day
> and night are to most people. And since this is no hermetism or
> esotericism I use them in the same way as the ideas of day and night and
> some million other things.

Then perhaps you are an Apple user.  I am not.  Millions of
potential readers of your message are not.  They will have
no idea what AAT stands for.  They will have no idea whether
or not they have an AAT renderer, or a Graphite renderer,
or any other renderer, as a part of their system.  This does
not mean that they do not know that it is dark when it is night :
they inhabit the same real world as you, but a totally different
world when it comes to computers and computing. [1]

I am not /blaming/ you, or anyone else : I am simply asking,
for the benefit of the vast majority of computer users that
do not use, and have zero experience of, an Apple Macintosh
computer, that when you (or others) make a statement that
is true only for the Apple Macintosh platform, you make that
plain, so that the rest of us do not spend hours wondering why
something does not work.

This is directly analogous to the statement in Will's XeTeX
documentation that "color" may take a fourth (transparency)
byte in the extended font syntax; the statement is true, but
it will have no effect when "xdvipdfmx" (the default driver)
is used to process the file.  Documentation is wonderful,
and everyone applauds those who write it, but for it to be
useful it must also be accurate.

>>
>> /Please/, when making platform-specific statements, make
>> this obvious in the message; it will save a great deal
>> of grief and misunderstandings in the long run.
>
> I did not make platform specific statements, I made software, font, and
> font renderer specific statements.
>
>
> Does Graphite work on any platform?

I have no idea.  I know that my pencil "lead" is
really graphite, and I know it can be used as a lubricant,
but what it means in terms of fonts is completely opaque
to me (and, I suspect, to millions of others as well).

> Why don't you complain here as well?

I am not complaining : I am asking for precision, which
is another matter entirely.

>
> Would it work to extend netiquette of this list to mention in the
> subject that the reported problem is specific to some OS so that
> recipients can put those OS words into their kill files?

What is a "kill file" ?  Another platform-specific feature, I suppose !

Philip Taylor
--------
[1] Apple Macintosh users are currently estimated as forming
less than 10% of the total worldwide computer base.  Data
taken from W3Schools, which I would not normally cite, but
I have no reason to doubt this statement.

http://www.w3schools.com/browsers/browsers_os.asp