On Mon, Mar 18, 2013 at 10:13:16AM -0500, Ian-Mathew Hornburg wrote: > Hello, and thanks to Khaled and contributors for their great work on this > project! I do work in Indic scripts, and XeTeX has been immensely helpful > in setting them. > > I may have identified two possible bugs in 0.9999.0: the release notes > indicate that the version-2 OpenType Indic script tags are now supported, > and I’ve been testing various Bengali-script fonts with the git version of > XeTeX and a current install of TeX Live 2012 to check them for correct > shaping behavior. I’ve posted a MWE reproducing some examples from the > Microsoft standard here: [http://pastebin.com/mgAX8c7U]. > > Microsoft ships two Bengali fonts (Vrinda and Shonar Bangla; both v6.80) > with Windows 8 that support both the older (beng) and newer (bng2) Bengali > script specs. (Older versions of each are shipped with Windows 7 and other > Microsoft products.) The fonts behave correctly when using the beng script > feature, with the exception of a particular ZWJ sequence: the Microsoft > spec [https://www.microsoft.com/typography/OpenTypeDev/bengali/intro.htm] > says that the sequence of consonant-hasant-ZWJ-consonant should prevent a > ligature of the two consonants, then render a half-form of the first > consonant. XeTeX currently fails to suppress the ligature.
This looks like a HarfBuzz bug, I can reproduce it with its test tool and indeed Uniscribe gives a different result. If you can report this to HarfBuzz developers, you will be able to describe the issue better than me, else I’ll try to report it. > However, when passing the bng2 script to the fonts, they both fail to > render correctly at all. I might guess that something’s going wrong because > the font contains both versions of the script tag, and I don’t know what > happens on the HarfBuzz side when selecting which script to use when > shaping a font. That is a XeTeX bug, the tags with parsed as ISO codes not OpenType tags. Should be fixed in the next point release. Regards, Khaled -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
