Surface runtime projecting Pure views across pixel, terminal, CLI, and web. http://git.yeowoo.org/vega/atom?h=master 2026-09-28T15:13:58Z 2026-09-28T15:13:58Z eunhhu necpition205@gmail.com 2026-09-28T15:13:58Z urn:sha1:ea6dbcf627e9a440590d0d35ff16ca7ae60d5719 The kern table's class subtables, OpenType's and Apple's, as HarfBuzz reads them (hb-aat-layout-kerx-table.hh, hb-ot-kern-table.hh): format 2's class tables give byte offsets into a kerning array, format 3's byte classes index a value list. Both go through the same pass as pairs (marks skipped, the kerning split between the pair). Format 2 filters the glyphs by the class tables' digests, as HarfBuzz's accelerator does, so a digest's false positive reads class 0 there too; what a subtable reads must lie within it, the last one's within the table. The build checks the subtables as HarfBuzz's sanitizer does, and still refuses state machines (format 1) and cross-stream kerning. text/test-kern.py makes fonts with format 2 and 3 subtables in every order, with the edge cases that reading has (value 1, glyphs outside a table, offsets below the array or odd, values past a subtable's or the table's end, classes and indexes past their counts): 24 fonts, 96 plans, the same as HarfBuzz. make check runs it where fontTools is. HarfBuzz's suite: 5017 of 5199 the same. 2026-09-28T15:07:05Z eunhhu necpition205@gmail.com 2026-09-28T15:07:05Z urn:sha1:cf6bcf8697589d2a6fc3c6d98bc52bf7eb1ea4ae The section now carries each sequence the font maps, a base and a selector, with the glyph HarfBuzz gives the pair (a default one's the base's own). As HarfBuzz's normalizer does, a sequence the font has becomes that one glyph, the two characters' clusters merged; one it lacks still passes on as two, the selector hidden. The header grows to 88 bytes for the table. The random check now mixes in the font's own sequences and stray selectors: 30000 runs over Noto Sans CJK's 14787 ideographic variation sequences are HarfBuzz's, and so are the installed fonts' and Noto's. HarfBuzz's suite: 5014 of 5199 the same, none different; what is left is what the build refuses and one run without a plan. 2026-09-28T15:04:05Z eunhhu necpition205@gmail.com 2026-09-28T15:04:05Z urn:sha1:960fa21762484d3014a6778a7673f15acf2d34bb The shaping section's character map came from hb_face_collect_unicodes. HarfBuzz's own suite showed where that list and its mapping part: it cuts a format 13 map short (AdobeBlank2's whole Unicode to one glyph), and a symbol map (3,0) it searches through the private use area, Latin and, in an old Arabic font, Arabic too. Now every code point is asked with hb_font_get_nominal_glyph (about 30 ms a font) and the map carried as groups: codes going to consecutive glyphs, or all to one (12 bytes each, so a format 13 map stays small). HarfBuzz's suite: 5011 of 5199 cases the same (1355 before). The installed fonts (213) and the Noto ones (21) still shape as HarfBuzz does on random runs. 2026-09-28T14:52:13Z eunhhu necpition205@gmail.com 2026-09-28T14:52:13Z urn:sha1:a4ca275ad1b5edc15474407e2852f8fe9abaac4e vega_layout takes fonts in order of preference (VegaFonts). A grapheme cluster goes to the first font that has all its characters (default ignorables aside: shaping hides them); a cluster of Common and Inherited characters stays in the font before it when that one has it, so the spaces between Arabic words stay in the Arabic font; failing that, the first font with its first character, else the first font. Runs split where the font changes too. Positions are in the first font's units, a run's pen scaled as a whole so rounding does not add up. Callers can narrow what a font has (a symbol file holds only the glyphs its codes reach). vega_default_ignorable is shape.c's HarfBuzz 10.2 set, now public. 2026-09-28T14:20:08Z eunhhu necpition205@gmail.com 2026-09-28T14:20:08Z urn:sha1:bafb710f0047751e26b87897eaf2a05609708536 The rest of HarfBuzz 10.2's Arabic shaper. Joining types now come from HarfBuzz's own table (Unicode 16, with Syriac's Alaph and Dalath-Rish groups the state machine's last two columns use), the general category deciding where it has none, so Syriac shapes with fin2, fin3 and med2. What stch multiplies is recorded and, after positioning, stretched under the word before it, repeating pieces copied as often as fit. A font with presentation forms but no Arabic features gets HarfBuzz's fallback lookups, which the build tool writes as OpenType and the runtime applies at their pause like any GSUB lookup. The generator now reads HarfBuzz's generated tables through their lookup functions' ranges and offsets: rows whose range starts mid-row have blank cells in front, which the row comments alone miscounted (Arabic Supplement); the Indic table, read again this way, did not change. Noto Sans Syriac, FreeSans's Syriac, Unifont's Arabic and Noto Sans Arabic shape as HarfBuzz does at 3,000 runs a plan; no installed font is refused any more (213 fonts, 1,822 plans). 2026-09-28T14:07:51Z eunhhu necpition205@gmail.com 2026-09-28T14:07:51Z urn:sha1:218298bb16ef6c147aa6dafc3ea88f62c6fa6ef6 The Thai shaper, from HarfBuzz 10.2's source: SARA AM comes apart into NIKHAHIT and SARA AA, the NIKHAHIT moving back over the above-base marks (and counting as a mark when advances are zeroed). A font with no Thai script of its own (only DFLT or latn in GSUB) gets its marks shifted to its private-use glyphs, Windows' before the Mac's, as the stacking around the base asks; the planner records, as HarfBuzz's does, whether the font had the script under its own tag. Noto Sans Thai and Lao, TLWG Loma, FreeSerif's Thai, DejaVu Sans's Lao and Unifont shape as HarfBuzz does at 3,000 runs a plan, and Loma with its thai script taken out (so the private-use path runs) at 5,000. 2026-09-28T14:03:30Z eunhhu necpition205@gmail.com 2026-09-28T14:03:30Z urn:sha1:5788d7e5bd6a26421346d69ae517502527940a0b The USE shaper, from HarfBuzz 10.2's source, for Sinhala, Tibetan, Javanese, Balinese, Mongolian and the rest of its eighty-odd scripts (and Indic fonts with the new dev3-style tags). The syllable machine reads past CGJs and ZWNJs that marks follow; rphf goes on each syllable's first glyphs and records the repha it made, pref records its pre-base glyph, with substitution marks cleared between; a repha moves before the first post-base glyph and pre-base vowels move back. Scripts that join like Arabic take Arabic's forms (Mongolian's free variation selectors their base's), the others join syllable to syllable. Marks lose their advances before GPOS. text/syllabic.py carries HarfBuzz's compressed USE table over as it is, compiles the USE grammar with the others (100,000 random runs against Ragel's machine: no syllable differs), and checks at compile time that the categories syllabic.h names are the machines' own. Noto Sans Sinhala, Javanese, Balinese, Mongolian, Noto Serif Tibetan, FreeSerif's Sinhala and Unifont's five shape as HarfBuzz does at 5,000 runs a plan; all installed fonts (1,748 plans) and 21 Noto fonts too. 2026-09-28T13:53:40Z eunhhu necpition205@gmail.com 2026-09-28T13:53:40Z urn:sha1:9bb85cffb10e0d4bc007406d1487a6dede3db975 Two more shapers on the syllabic groundwork, from HarfBuzz 10.2's source. Khmer reorders before any lookup: a coeng and Ro go before the base, masked for pref, what follows them for cfar, a left matra goes first; split matras decompose with U+17C1. Myanmar finds the base after a kinzi, gives each glyph its place around it and sorts by place, and zeroes mark advances before GPOS rather than after. Noto Sans Khmer and Noto Sans Myanmar shape as HarfBuzz does at 20,000 runs a plan, and so do Unifont's Khmer and Myanmar (no GSUB). 2026-09-28T13:49:05Z eunhhu necpition205@gmail.com 2026-09-28T13:49:05Z urn:sha1:60a3c0232bbca8d5d8c1107ab8197d272212ef42 The Indic shaper, from HarfBuzz 10.2's source: syllables found by the Indic machine; each syllable's base consonant, its pre-base matras and reph moved around it and masked for the basic features, applied one at a time within the syllable; then matras, reph and pre-base-reordering consonants placed again by what the features made. Vowel constraints, Indic decompositions and compositions, dotted circles for broken syllables, and per-syllable matching come with it. Plans carry GSUB pauses (steps where the shaper does its part) and the stages of the features the shaper asks whether they would substitute; the runtime answers with each subtable's would_apply, as HarfBuzz does. Masks are now the common ones and each shaper's own. text/syllabic.py reads HarfBuzz's Ragel grammars (Indic, Khmer, Myanmar) and compiles each to a minimal DFA with Ragel's scanner semantics; beside the machines Ragel generated from the same grammars, 100,000 random runs each find no syllable that differs. It also reads HarfBuzz's Indic table (Unicode 16) cell for cell. Every installed font shapes as HarfBuzz does (213 fonts, 1,688 plans); the Indic ones at 20,000 runs a plan (FreeSerif's eight scripts, FreeSans, Unifont's nine without GSUB), and nine new-spec Noto Sans fonts at 5,000. 2026-09-28T12:54:31Z eunhhu necpition205@gmail.com 2026-09-28T12:54:31Z urn:sha1:88e16d6f971287afd0ab15d1cde73608cde43b1b The planner now picks who positions as HarfBuzz 10.2 does: GPOS, the old kern table when GPOS has no kern feature, and marks placed by combining class and ink boxes when there is no GPOS; the Hangul shaper composes syllables the font has whole, takes apart those it lacks into jamo for ljmo, vjmo and tjmo, and moves tone marks before their syllable. The section grows to an 80-byte header (the kern table, and each glyph's ink box when a plan places marks without GPOS) and 88-byte plans (the kern mask, the jamo masks). Kern tables are applied pair subtable by pair subtable with HarfBuzz's own binary search; state machines, class subtables and cross-stream kerning, which no installed font has, are refused. The check spells Hangul syllables every way text does. Every installed font Vega accepts shapes as HarfBuzz does (209 fonts, 1,520 plans, a thousand runs each), and the fonts refused before at 20,000 runs a plan: Noto Sans CJK KR and Baekmuk for Hangul, IPA Gothic and Noto Mono for marks without GPOS, FreeSans, FreeSerif, Liberation and DejaVu Sans ExtraLight for kern tables, Unifont's Latin, Greek, Cyrillic, Hebrew and Hangul.