BabelStone Fonts

BabelStone Zanabazar

Description

BabelStone Zanabazar is a Unicode font for the Zanabazar Square script, which was encoded in Unicode version 10.0 (June 2017). The Zanabazar Square script, known in Mongolian as Хэвтээ Дөрвөлжин бичиг or Хэвтээ Дөрвөлжин Үсэг ("horizontal square script"), was devised by Zanabazar (1635–1723) for use in writing Mongolian, Tibetan and Sanskrit. It was rarely used outside of descriptions of the script and in calligraphy manuals.

Block print of Zanabazar's square script, from his collected works edited by the Khalkha Zaya Pandita Luvsanprinlei (1642–1715) (from L2/15-337 Fig. 1)

Rendering

The BabelStone Zanabazar font supports complex shaping behaviour using OpenType features, but whether these features are applied or not depends on the operating system and the text rendering engine. Windows 10 uses the Universal Shaping Engine, which does not currently support Zanabazar Square.

As of February 2018, Zanabazar Square text displayed with BabelStone Zanabazar font does not show any complex shaping behaviour in Microsoft applications (or other applications that rely on Microsoft rendering) under Windows 10. Zanabazar Square does not currently render correctly in the latest version of Mozilla Firefox. However, Zanabazar Square is supported by the latest version of HarfBuzz, which is used in the latest version of Google Chrome, although there are some rendering issues as reported here.

Issues

A. Order of Vowel Signs

A single vowel cluster may take one or two vowel signs and a vowel length mark, but as Zanabazar Square vowel signs and the vowel length mark (U+11A0A) all have a Canonical Combining Class of zero, they do not reorder under normalization, and so there is no canonical order for vowel signs and vowel length. Moreover, the Unicode Standard does not clearly specify the correct ordering of vowel signs and the vowel length mark, so users may not know what the correct order is, and multiple different sequences may give the same visual result. Under HarfBuzz some sequences render correctly but other sequences of the same vowel signs and length mark may not render correctly (see HarfBuzz, although there are some rendering issues as reported HarfBuzz Issue 617 for details).

The order of the vowel length mark is particularly problematic from my perspective. Anshuman Pandey, author the Zanabazar Square encoding proposal suggests that the length mark should be placed after a vowel sign (if present) in most cases, but in some cases he suggests it should be placed between two vowel signs (see L2/15-337 p. 6). Firstly, as the length mark ligates with the preceding consonant, it is much easier from the font designer's point of view to deal with the ligature if the length mark directly follows the consonant it ligates with. It adds considerable time and effort to the font design to define OpenType substitutions that can deal with all potential orderings of the length mark with respect to vowel signs. Secondly, as the vowel length mark corresponds directly to the a-chung mark in the Tibetan script (U+0F71), which follows directly after the last consonant in the stack and before any vowel signs, it is natural for users familiar with the Tibetan script to enter the Zanabazar vowel length mark after the last consonant in the stack and before any vowel signs.

B. Head Letters La and Sa

The Tibetan script has three head letters that can be superfixed to a consonant (Ra, La and Sa), of which the Ra head takes an abbreviated form in native Tibetan words. The Unicode implementation of the Zanabazar Square script defines a special ligated half-height "Cluster-Initial Letter Ra" (U+11A3A) that corresponds to Tibetan Ra head and which is used in Tibetan stacks, in contrast to the ordinary consonant Ra which is used at the top of Sanskrit stacks. In Tibetan the La and Sa head letters have the same form as La and Sa at the top of Sanskrit stacks, but examples of Zanabazar Square script included in L2/15-337 show that La and Sa at the top of Tibetan stacks are normally written with ligated half-height forms rather than as the unligated full-height forms that would be expected in Sanskrit stacks.

Tibetan rka, ska and lka in Zanabazar Square script

There is currently no way to distinguish the ligated half-height forms and the unligated full-height forms of La and Sa, and so the font designer has to make a decision at to which forms to use. BabelStone Zanabazar uses the ligated half-height forms in all cases as Tibetan use of these head letters is much more common than Sanskrit use in complex stacks. I made a proposal to encode Cluster-Initial Letter La and Cluster-Initial Letter Sa to solve this problem (see WG2 N4945), but this proposal was not accepted due to insufficient evidence.

Character Repertoire

The tables below render each character in the BabelStone Zanabazar font (excluding Basic Latin characters), either using the font installed on your local machine or using a WOFF font if the font is not installed on your local machine.

Zanabazar Square [11A00..11A4F]

Tibetan [0F00..0FFF]

OpenType Features

Version History

Download

BabelStone Zanabazar is licensed under the SIL Open Font License 1.1, which means you are free to use it for personal or commercial purposes, and to redistribute it by itself or as part of a free or commercial software package, just as long as you do not sell the font on its own. The license also allows you to modify the font in any way you like, as long as the modified font does not use "BabelStone" in its name. Please read the license for details.

For use on your computer or mobile device please download and install the TTF file. The WOFF and WOFF2 files are for web use only, and are not required by most users.

BabelStone Fonts