Indic font rendering incorrectly about bevy HOT 1 OPEN

I do not know how to fix this but I decomposed the string into its code points.

రాష్ట్రముల మధ్య

Code points:

U+0C30		ర
U+0C3E		ా
U+0C37		ష
U+0C4D		్
U+0C1F		ట
U+0C4D		్
U+0C30		ర
U+0C2E		మ
U+0C41		ు
U+0C32		ల
U+0020		 
U+0C2E		మ
U+0C27		ధ
U+0C4D		్
U+0C2F		య

The first character looks like a ర with a ◌ా nonspacing mark (U+0C3E) appended. The combining mark is tacked on, but the glyph should render differently when it is applied. They should combine as a రా.

The next visual glyph appears to be made up of five code points, which render completely differently if any are removed. This is me pressing backspace on the second glyph:

ష్ట్ర ష్ట్ ష్ట ష్ ష

For this glyph, the first two code points U+0C37 U+0C4D combine to make ష్ but the second and third code point U+0C4D U+0C1F combine to make ట్, yet the fourth and fifth code point combine to make ్ర. Maybe something is parsing the TTF wrong with the grapheme clusters?

Is this a limitation of the ab_glyph crate that bevy_text uses internally?

Does anyone have any thoughts?

EDIT: I wonder if down the line we could make use of something like rustybuzz as a text shaping engine for complex scripts like Indic or Hebrew. Bevy doesn't seem to support right-to-left languages either at the moment.

from bevy.