[XeTeX] The future of XeTeX

Keith J.Schultz keithjschultz at web.de
Tue Jul 31 17:41:02 CEST 2012

Hi Jonathan, All,

I have to disagree with you! Yet, the disagreement is on fundementals.
Apple, themselves state that MOST of the ATSUI features are no longer supported.

You can get some of that functionality back using Core Text, though most you
will have to by hand using Core Graphics. 

Also, we would have to decide on what exactly is a true AAT-Font. Or at least 
what minimal set of tables constitute a true AAT-Font most of ATSUI was based on using
these tables. Some of the tables are in use today by Apple for handling language scripts.
So, in a sense many of the TT-Fonts on the Mac are AAT-Fonts. But, who am I explaining
this to.

I remember a discussion we had about switch XeTeX from ATSUI to Core Text and you basically
said ATSUI was just used for font handling not rendering. 

Well, I do not see why Lua should not be up to that task. 

I never thought for one moment that there would be a clone API in Core Text to ATSUI. 
As a matter of fact to get the ATSUI, functionality you have to use more than a couple of
Apple APIs, where Core Text is just the begining.


Am 31.07.2012 um 11:34 schrieb Jonathan Kew <jfkthame at googlemail.com>:

> On 31/7/12 10:06, Keith J. Schultz wrote:
>> Hi All,
>> I will step in and offer my 2 Euro cents worth.
> ...of misinformation, I'm afraid.
>> First, we have to be careful not to mix oranges and apples.
>> That is to say font formats ,  font feature sets, rendering engines
>> and tex formats and tex engines. They are all different animals.
>> Let us take ATSUI. Why has Apple abandon it? Well, I do not believe
>> there are are any native ATT-fonts in the MacOS X any more.
> What you happen to believe (or not) is irrelevant (and misleading). OS X ships with a bunch of AAT fonts. (There are also some available from third parties, though not large numbers.)
>> Is Core Text a alternative? Not, actually.
> Yes, actually. Core Text is the modern, supported replacement for ATSUI functionality.
>> Core Text does have some
>> support for ATSUI, but it is not 1 to 1.
> Well, of course not; it's a different API. What would be the point of replacing an old, deprecated API that doesn't fit in with other modern APIs on the system with a 1-to-1 identical reimplementation? The replacement happened in order to modernize both the implementation and the interface.
> Core Text doesn't have "support for ATSUI" in the sense of providing a set of ATSUI-clone APIs to applications, but it most certainly does have support for AAT fonts, which is the relevant issue here.

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