awaforge

aatProp

AGPL-3.0-onlyRelease 2L4

Table prop — Glyph Properties (Apple TT RM06).

Module aatProp | Source packages/front/office/fonts/src/extra/apple-aat/prop.js | Deps fontErrors, fontReader | Worker-safe yes

Per-glyph properties (directionality, floating accent, hanging) — either a global default (format=0) or an AAT lookup (format=1). The AAT lookup itself (formats 0/2/4/6/8/10) is never decoded — format=1 only reads the lookup table's 2-byte lookupFormat header and keeps the rest as raw bytes; lookup(gid) always returns defaultProps for every glyph, regardless of format. This is the module's explicit state-machine-deferred stub — see reason below.

Exports

Symbol Type Description
PROP_BITS const { DIRECTION_MASK, IS_FLOATER, HANGS_OFF_LEFT, HANGS_OFF_RIGHT, USES_COMPLEX_OT, ATTACHING } bit masks for the 16-bit per-glyph property word (prop.js lines 20–27).
parseProp function (bytes) => { version, format, defaultProps, lookup } for format=0; { version, format, defaultProps, lookupFormat, lookupBytes, parsed: false, reason: 'aat-state-machine-deferred', lookup } for format=1. The lookup function (always present, both formats) and, for format=1, lookupFormat/parsed/reason were missing from a previous revision of this page (prop.js lines 32–77).
aatProp factory Factory.

Usage

import fw from '@awacloud/fw';
import { fw_require, modules, extras } from '@awacloud/fonts';

for (const m of [...fw_require, ...modules, ...extras]) fw.runtime.register(m);
const { parseProp, PROP_BITS } = fw.runtime.resolve('aatProp');
const prop = parseProp(sfnt.tables.prop.bytes);
prop.lookup(glyphId); // always defaultProps today, even for format=1

Notes

  • Fixed versions 1.0 / 2.0 / 3.0 are accepted.
  • format=1's returned object explicitly signals its stub-ness via parsed: false, reason: 'aat-state-machine-deferred' — the one AAT module in this directory that documents the deferral this way at runtime (contrast ankr/lcar, which give no signal — see ./README.md).
  • Requires the fonts-apple-aat bundle.

See also