OpenType and Apple's ATSUI

[_Jose_Luis_Acosta_]

ATSUI (Apple Type Services for Unicode Imaging) is a Mac OS X's API for rendering Unicode text.

Checking the "Inside Mac OS X" documentation on this API, I saw that it offers lots of system-level support for fonts that includes precisely the kind of features found in OpeType fonts (although the document never mentions OT fonts explicitly).

One can see an implementation of ATSUI in TextEdit, the basic text editing application in the new Mac OS, as long as one selects one of the ATSUI-featured ".dfonts" that come preinstalled, like Zapfino. I tried Warnock Pro OT on this editor and found that nothing happened when I requested a ligature or some other feature.

My question is: Does anyone knows if there is any implemented interaction between ATSUI and OpenType, as it were logically expected since the two technologies address similar issues to a great extent? As I see it, this would make somewhat easier to give support for OT features in Carbon or Cocoa apps.

Thanks.

JL

[Thomas Phinney]

This is covered in my article on font formats, a reasonably recent version of which is available here:
http://www.font.to/downloads/TT_PS_OT.pdf

The short answer is that ATSUI currently supports AAT advanced typography, which is essentially a re-branded GX typography, which has been around since 1991. This is a Mac-only solution, which is why none of the major cross-platform applications has ever supported it.

As of Mac OS X 10.2, ATSUI does not currently support the advanced layout features of OpenType. Apple has made some comments in public that suggest they might add more OpenType support in the future. However, due to non-disclosure agreements between Apple and Adobe, I can't comment more on their future plans.

Regards,

T

Thomas Phinney
Fonts Program Mgr.
Adobe Systems

[_geertdeg_]

Mr. Phinney, I read in your document that Adobe implemented Unicode in InDesign 2.0 independent of the Operating System. This is very nice and InDesign 2.0 has saved me already lots of time for our East-European language designs.
But does this mean that e.g. Quark XPress will never support the extended OpenType/Unicode character set properly until either Apple modifies their ATSUI implementation to support Adobe's OpenType fonts or until Quark also build their own Unicode implementation?
I hope that Adobe will also implement Unicode-support in the next version of Illustrator 11. The combination InDesign/Illustrator with support for Unicode will have a great advantage over XPress in my opinion.

[Thomas Phinney]

Yes, on the Mac, Quark would have to either roll their own OpenType support or wait to see if Apple did it. However, there's not reason they couldn't use the system services for Unicode support on both Mac and Windows, if they wanted.

There are also open source libraries for Unicode support, such as FreeType, and IBM's ICU library.

I can't comment on Adobe's plans for unannounced future products, I'm afraid.

Regards,

T