Or may be the dotted cicle is mapped in that font to a null glyph (non standard feature). I can't check that, I dont have this Pothan2000 font.
My opinion is that Uniscribe does not handle correctly the sequences where the anusvara U+0C02 (shown here with the visible dotted circle) follows the avagraha Sanskrit sign U+0C3D (the latter was supposed to follow only a consonnant cluster+optional dependant matras). I can't see any description of the expected behavior for this case in http://www.microsoft.com/typography/otfntdev/teluguot/shaping.htm It is not clear in OpenType specs how the Anusvara=Sunna U+0C02 sign will behave in the shaping engine (but this is also true for the Candrabindu=Arasunna U+0C01 and the Visarga U+0C03 signs). The specs only discusses about clusters of consonnants, halants and vowels, plus the special Akhand subclusters, optionally followed by "SM - a stress or tone mark (e.g. Udatta, Anudatta, Acute, Grave)" or "LM - a length mark". And I'm not convinced about where the four signs U+0C01..U+0C03 and U+0C3D will fit in the documented character categories. Apparently their expected behavior is not specified, the shaping engine has its own internal rules to decide when to insert a dotted circle or not before these four signs. But this does not require any OpenType feature in fonts, the shaping engine will just look for the mapping of the dotted circle glyph, and will insert it according to its own rules. -- should the Anusvara behave like a postbase consonnant ? should there be a "psts" feature in fonts to support the Anusvara correctly (even ifit's not a consonnant or vowel matra) ? But similar cases occur in some other Indic scripts that use prebase or postbase modifier signs that are not consonnants or vowel matras. 2013/5/11 Shriramana Sharma <[email protected]> > On Sat, May 11, 2013 at 2:24 AM, James Cloos <[email protected]> wrote: > > > > Further testing showed that pango and harfbuzz get it right when using > > the font Pothana2000, and fail with every other font I have to test. > > Is it because Pothana doesn't have the dotted circle glyph? > > -- > Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा > > >
