RE: Prepending vowel exception in Lontara/Buginese script ?

Here's a portion of the description of the 'pref' feature tag in the OpenType tag registry:

Function: Substitutes the pre-base form of a consonant.

In some scripts of south or southeast Asia, such as Khmer, the conjoined form of certain consonants is always denoted as a pre-base form. In the case of some scripts of south India, variations in writing conventions exist such that a conjoined Ra consonant may be written as a pre-base form, or a below-base or post-base form. Fonts may be designed to support one or another convention. If a font is designed to support a writing convention in which conjoined Ra is a pre-base form, the Pre-Base Forms feature would be used.

Example: In the Khmer script, the consonant Ra has a pre-base subscript form called Coeng Ra. When the sequence of Coeng followed by Ra occurs, its pre-base form is substituted.

Peter

-----Original Message-----
From: unicode-bounce_at_unicode.org [mailto:unicode-bounce_at_unicode.org] On Behalf Of vanisaac_at_boil.afraid.org
Sent: Saturday, July 23, 2011 11:35 PM
To: Peter Constable; vanisaac_at_boil.afraid.org; unicode_at_unicode.org; Philippe Verdy
Subject: RE: Prepending vowel exception in Lontara/Buginese script ?

From: Peter Constable <petercon_at_microsoft.com>

> Van is mistaken in his understanding of OpenType Layout. There is no
> mechanism to describe re-ordering in OpenType Layout tables in a font.
> That must be handled by the OTL client software.
>
> Peter

Well crapola. So that reordering is completely controlled by Unisribe, Peter?
Then what is the pre-base forms/substitution OT features for? I had always thought that vowel reordering was their purpose.

-Van
Received on Mon Jul 25 2011 - 13:12:53 CDT