payv 0.1.1

Pure-Dart OpenType shaping and vector PDF generation. Renders Kurdish Sorani, Arabic, Persian and Urdu by executing the font's own GSUB/GPOS tables. No FFI, no dependencies.

Changelog

0.1.1 — 2026-08-18

One correctness fix, plus packaging.

Fixed — a table's version tail could decode out of the NEXT table

OpenTypeFont now passes each table's directory-recorded length to the parsers whose format has a version tail: OS/2, post and maxp.

SfntFile.table() hands back a reader over the whole file positioned at the table — deliberately, because an OpenType offset may point backwards into a parent and slicing per table would break real fonts. The consequence was that a parser's own bounds check asked "does the FILE have room", and for any table that is not the last one the answer is always yes. A version word claiming more than its body holds was therefore believed, and the tail decoded out of whichever table happened to follow.

Measured on Vazirmatn with its OS/2 version word flipped to 5 over a 96-byte body: usLowerOpticalPointSize came back as 908, read out of post. On that path sCapHeight and sxHeight are fabricated the same way, and both go straight into the PDF /CapHeight and /XHeight. post was reading its glyph names — and maxp its outline limits — out of the following table under the same conditions.

Only malformed or unusually-truncated fonts reach it; a well-formed face is unaffected, and no output changes for one. doc/DEFECTS.md O3 has the full account, including why the parameter existing and being tested was not enough.

Packaging

• Shortened the pubspec description to the 60–180 characters pub.dev's analysis asks for.
• Dropped the documentation: field. pub.dev generates and links the API docs itself; pointing the field back at that same URL only created a link that is unreachable until the docs finish building.

0.1.0 — 2026-08-18

First release.

• Pure-Dart OpenType layout engine. GSUB types 1–8 and GPOS types 1–9, executed against the font's own tables, so glyphs that exist only as the output of a lookup — and have no Unicode codepoint at all — are reachable. This is what makes Kurdish Sorani render correctly: ڕ ڵ ە ێ have no presentation forms in Unicode, and neither does the ڵ+ا ligature.
• Arabic joining state machine with the transparent mark class, ZWJ/ZWNJ, tatweel, and the fin2/fin3/med2 features.
• UAX #9 bidi, including isolate formatting characters and paired brackets.
• Variable-font support — fvar/gvar/avar/HVAR, with static instancing, because a PDF cannot carry a variable font.
• Font subsetting with composite-glyph closure.
• PDF 1.7 writer — CIDFontType2 / Identity-H, embedded subsetted fonts, ToUnicode CMaps, and RTL text stored in visual order so every extractor reads it back correctly.
• Zero runtime dependencies. No FFI, no platform channels; runs on the VM, in Flutter, and on the web.
• Graded byte-exact against HarfBuzz: 53 corpus cases, 371 glyphs, 16 distinct GSUB-only glyphs.