AAT Font Quality Specification
(AAT) AAT Savvy Guidelines, as relate to fonts.
What is AAT-savvy?
AAT, the new imaging architecture for Macintosh, provides advanced,
system-level functionality for graphics, type and typography, printing,
and color management. By building on the capabilities of QuickDraw GX,
you'll be able to add powerful, differentiating new features to your products
faster than ever before.
We've defined what it means for a third-party product to be AAT-aware,
as well as what constitutes a truly AAT-savvy product. Please review these
guidelines carefully. They are organized by product category under sections
for both Aware and Savvy. The final section of this document, Technical
Details, contains recommendations for writing to QuickDraw GX. By conforming
to the aware and savvy standards, developers and end users will have an
accurate way of gauging a products adoption of AAT features.
The AAT product marketing team is working hard to create focused, solutions-based
marketing programs to promote adoption of the technology. We are looking
for extremely cool, AAT-savvy products to participate in marketing and
promotion efforts. We hope that these guidelines will help you direct your
efforts. (...)
AAT AWARE
The AAT-aware definition is designed to allow customers to identify
those products that are well-behaved under AAT and take advantage of features
of the new print architecture, including font embedding and portable digital
documents (PDDs). Because this is a relatively easy definition to meet,
a large number of products will qualify as AAT-aware. As a developer, you
should seriously consider making your products AAT-savvy to provide differentiation.
(...)
AAT SAVVY
The definition of AAT-savvy will provide developers, Apple, and end-users
a way to identify truly new, breakthrough products. Savvy applications
will set new standards for graphics, type, printing, and color functionality.
(...)
Typography
1. Applications must test that they work with bitmap, TrueType, Type1,
and all matter of AAT fonts. A. Applications must call ATSUI to handle
all text. Applications must use layouts for all text drawing. B. Applications
should not call ATM (Adobe Type Manager) directly or make use of other
backdoors (see list of AAT-replacements for existing backdoors) 2. Applications
should make any and all named AAT font layouts and variations available
to users through support for HI font guidelines. In other words, named
layouts and variations should refer to feature sets and instances 3. Applications
should provide direct, dynamic control for type resizing, kerning, spacing,
condensing, and so on. A. This corresponds to a AAT-Savvy Plus feature.
We would not demand it of everyone, though we would strongly recommend
it. 4. Applications should save named instances and feature sets. This
will help maintain predictability for users as they experiment with different
fonts and settings.
AAT Fonts
1. Developers must run all AAT fonts through Font Validator (test tool).
A. Font developers should create extremely clean fonts, and strive to eliminate
all errors and user warnings. 2. GX fonts must have a font description
('fdsc') table. 3. If an AAT font contains layout features, it must have
at least one feature set. A. A font should provide minimal layout tables,
including kerning, justification, properties, baselines dependent on language,
and so forth. Refer to the font guidelines in the Font Table format specification.
4. If an AAT font contains variations, it must have at least one instance.
5. Use registered tags for the above. A. A font developer should register
with ITS the tags they create in their font. 6. An AAT font must provide
localized names and 'cmap's for script support. 7. An AAT font, even if
it is a variation of an existing PostScript font, MAY NOT use the same
name in its naming table as the PostScript font. 8. Fonts must follow Human
Interface guidelines for icon design. 9. Any Type 1 font must be shipped
in the 'sfnt' font structure. 10. AAT Fonts must be embeddable. 11. The
specific features, functionality, and glyphs in an AAT font depends entirely
on the design and intended purpose of the font. However, many font developers
have asked for a list of features that should be included in an AAT font.
In general, AAT Roman fonts should include the following characters and
functionality:
Extensive tracking and kerning information to provide high-quality,
properly-spaced results over a wide range of point sizes and character
combinations. An incomplete list of kerning pair suites should include:
Ligatures
Default ligatures are ligatures which occur automatically for typographic
reasons and should be in every AAT font:
fi fl fb ff fh fj fk fr ft ffb ffh ffi ffk ffl ffr
Rare ligatures are glyphs which are ornamental and interesting, but
should be used with discretion. For a serifed font they include:
st, ct, ty, as, es, is, ns, nt, st, tt
For a sans-serif face they include:
CT, CC, CO, CT, HE, LA, LE, LI, LL, MB, MD, ME, MP, NK, NT, RA, ST,
TE, VA
(NOTE: These are particular to a particular font style, and are subject
to a designer's particular taste).
Diphthong ligatures include: oe ae OE AE
In addition, some ligatures may lend themselves to having alternate
swash forms, for line endings or beginnings, such as: ft, ct, st, nt, tt,
oe, ae, OE, AE.
Automatic fractions
Diagonal fractions will occur contextually by default when a user types:
(numerator) figures, Option-Shift-1, then (denominator) figures. The fractions
will be automatically created via Line Layout, which will call the glyphs
in question. When creating the table, use the fraction bar (glyph #188/character
#218).
Do not allow fractions to be created automatically using the slash (glyph#18/character
#47)! That would be a human interface faux-pas.
In addition to 0123456789, numerators and denominators can include:
( $ ¢ + - . , )
Correct, automatic superscripts and subscripts
Two sets of miniature, lower case glyphs share the same 27 outlines:
a through z and e-grave.
Ordinals
1st, 2nd, etc. Hint: design the glyphs that follow the figures to sit
at the right height.
Correct small caps
In addition to drawing small caps for the standard Roman alphabet set
, add the international glyphs and an assortment of useful punctuation:
Don't forget about oe and ae diphthong ligatures.
Also, you will need to provide two rather odd glyphs: 1) copy the small
cap outlines of f and l, and f and i, next to each other into a single
glyph location. Then map the standard Macintosh characters fi (opt-sh-5)
and fl (opt-sh-6) to these new glyphs. Otherwise, when users select a stream
of text which has the [shift-option] ligatures, a small cap version of
FL and FI will not be available.
Space Glyphs
A font should include a variety of space glyphs, such as the en space
(1/2-em), hair space (1/5 of an em, or 5-to-em), and thin space (1/4 em,
or 4-to-em).
Old-style numerals
Tabular figures (monospace)
Swash characters (for serif faces)
Optical alignment
Hanging punctuation
Vertical substitution to support vertical characters of non-Roman text
(i.e. Japanese)
Two axis fonts (an axis might include weight, ornateness, color, slant,
outline thickness, appearance randomization, etc.) (...)
Arleigh Movitz
The Apple Fonts Group
