Files
pdfcraft/crates
e33b66e9b5 Edit text: support per-font visual-order Indic text and nukta reordering (#1380)
* Edit text: support per-font visual-order Indic text and nukta reordering

- Detect legacy visual-order Indic fonts via Metrics.visual_order (fonts with
  Indic codepoints without OpenType GSUB tables, or legacy visual font names).
- Implement Indic visual-to-logical and logical-to-visual pre-base vowel
  reordering in crates/edit/src/indic.rs, with support for decomposed/precomposed
  nuktas and conjuncts.
- Apply reordering during extraction and source font reuse only when visual_order
  is set, leaving modern logical-order text untouched.
- Add unit tests for nuktas, conjuncts, and round-trips in crates/edit/src/indic.rs
  and font visual_order tests in crates/edit/src/tests.rs.

* Visual-order Indic: positive evidence only, ActualText kept logical, no font decoding

- A font is visual order only when it is a known legacy Indic family (subset tag
  allowed; aps-/dv- as prefixes) with an Indic Unicode mapping. A missing GSUB is
  no evidence (bare CFF and subset fonts drop it), so Metrics::from_dict no longer
  decodes every embedded font program on every call.
- Lines with /ActualText text are already logical: skip indic::to_logical, so
  "बढ़िया" no longer becomes "बढ़यिा".
- reading_lines no longer runs bidi recovery on every line (it changed RTL
  reading_blocks output for all documents); only the Indic recovery remains.
- indic.rs indexes through get().
- Tests use a ToUnicode fixture (not visual-order ActualText), cover an edit
  round-trip, logical ActualText in a legacy font, and a subset Noto font.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-12 08:18:37 -04:00
..