Post #1808012

2026-03-09 15:47 UTC

@justvanrossum @frankrolf @mathieureguer This example requires something like a reverse Indic shaping engine within the PDF viewer. The arching form from the left is the vowel sign (ikar) that is the last character in the sequence (so needs to be reordered from the beginning to the end). In this font, it is forming a ligature with the hook form above right (repha), which is the first two characters in the sequence (so need to be reordered to the beginning). So that ligature needs to be decomposed during parsing, and then the parts correctly identified and reordered according to rules. There is no provision within the existing Adobe glyph naming rules for this ligature.

Replies (1)

@TiroTypeworks@typo.social 2026-03-09 15:58

@justvanrossum @frankrolf @mathieureguer I’m thinking through repha identification, and it is perhaps more algorithmically simple than I thought. In this case, the first glyph in the string is the ikar + repha ligature. If this were named in a way that actually ignores the underlying character order, as /uni093F0930094D, then it would decompose to ikar + ra + halant, and simply reordering the parsed vowel sign character to the end of the cluster would leave the ra + halant where they belong at the beginning of the cluster. In most other cases, the repha is going to be at the end of the glyph string, so then the parser needs to idenfity a trailing ra + halant at the end of a conjunct as a special case and reorder them to the beginning.

Open ##1808013