442161 - Add default Mac font for Sinhala

Status: RESOLVED WONTFIX

(Core :: Graphics, defect)

Description

[Smokey Ardisson (offline for a while; not following bugs - do not email)]

Bug 426957 comment #11 - Nicholas Shanks  2008-06-26 06:34:56 PDT

I did a Sinhala AAT version of the OpenType Unicode font "Malithi Web" which is
available in early form from http://web.nickshanks.com/typography/sinhala/ and
Tom Gewecke is working on a keyboard layout for it. There are many two main
issues at the moment, but it is usable to some degree. More so than a font with
no AAT rules at the least.

---

Nick, how does this font compare (problems/usability) to the fonts we're already using for Kannada and Telugu?  The disclaimers on your site are more-or-less identical, and if Malithi Web compares well with the ones we're currently assigning, it should be OK for us to set it as a default.

Comment 1

[Nicholas Shanks]

I would recommend that you set the Xenotype fonts to be primary font and mine to be the fallback.
I don't know the font names names, but you can email Kaʻōnohi Kai at "dkai commercial-a-in-a-circle-sign xenotypetech.com" and ask.

To specifically answer your question, this font is much worse, as indicated by it's 0.5 version number relative to the others' 0.9x version numbers. Specifically it can't cope with zero width joiners, which are common in Sinhala, and only about half of the vowels are supported.

The main benefits are with the two hundred and ten ligatures formed from consonants and the al, i, ii, u, uu, vocallic-r and vocallic-rr vowels. These ligatures already existed in the OpenType font and enabling them was fairly trivial.
The e and ai vowels are rearranged correctly, so they also work.

The a, ae, aee, ee, o, oo and au vowels all use 1 unicode point but require this to be decomposed into two glyphs so that the first component can be rearranged in front of the consonant. Glyph insertion is something that AAT cannot do (it only does replacement, glyph deletion is simulated by replacing with a DEL (null) glyph). To resolve this someone (I don't have the time) will have to create compound glyphs in the font that will enable glyph substitution so that the number of glyphs needed doesn't exceed the number of unicode characters used.

The original OpenType font was also missing 4 unicode codepoints used in archaic Sinhala (nyja U+DA6, U+D8F, U+D90 & U+DF3), 3 ligatures based on njya, and the three stand-alone vocallic L glyphs which are only used in discussion and education about the vowels, and do not otherwise appear in prose.

Comment 2

[Smokey Ardisson (offline for a while; not following bugs - do not email)]

Typically our "policy" has been to set defaults to OS-shipped fonts, with free (and on occasion shareware in absence of a free option) fonts in the absence of a proper shipped-with-the-OS font, and eschew commercial fonts.

Given that and comment 1, I think it's probably best if we continue to set no defaults at this point.  For those who do have the Xenotype fonts (or your version of Malithi Web) installed, fallback should do the right thing, albeit with a bit of a delay (and I'd expect that most people who do install these fonts would be able to find and change the settings themselves).

Simon, John, what do you think?

Comment 3

[Simon Montagu :smontagu]

I agree with Smokey

Comment 4

[Nicholas Shanks]

Okay. I will update this bug once my font is at the level of usability of the other two (where the only issues are kerning at larger sizes and lack of hinting at smaller sizes).