From: John Hudson <>
Date: Mon, 22 Aug 2011 09:58:13 -0700

Shriramana Sharma wrote:

> The font tables themselves contain only ASCII characters I presume.

OpenType Layout tables use Glyph IDs. OTL development tools typically
use glyph names, which may be particular to the tool or the same names
used in the post or CFF tables.

OTL tables work on glyphs, not characters, and bidi will have been
resolved prior to application of OTL substitution and positioning. Input
glyph strings for substitution lookups are always in the resolved
direction of the glyph run, so Arabic and Hebrew alphabetic runs are
processed right-to-left, i.e.

        alef lamed -> alef_lamed


        lamed alef -> alef_lamed

Similarly, context stings for glyph positioning (if present) will be
right-to-left, although anchor attachment positions on individual glyphs
are relative to the 0,0 coordinate, i.e. the left sidebearing.


Tiro Typeworks
Gulf Islands, BC
The criminologist's definition of 'public order
crimes' comes perilously close to the historian's
description of 'working-class leisure-time activity.'
  - Sidney Harring, _Policing a Class Society_
Received on Mon Aug 22 2011 - 12:01:15 CDT

This archive was generated by hypermail 2.2.0 : Mon Aug 22 2011 - 12:01:16 CDT