awaforge

tablePost

AGPL-3.0-onlyRelease 2L4

Table post — PostScript Information (OT §6.4.9), versions 1.0 / 2.0 / 3.0 / 4.0.

Module tablePost | Source packages/front/office/fonts/src/table/post.js | Deps fontErrors, fontReader, fontWriter | Worker-safe yes

Versions:

  • 1.0 — fixed header (32 bytes); glyph names implicitly = the Mac standard 258.
  • 2.0 — header + numGlyphs index + pascal strings.
  • 2.5 — not supported (deprecated, throws).
  • 3.0 — header only, no glyph names.
  • 4.0 — the version tag is recognised but decoding is not implemented: parsePost falls through with only the base header fields, no character-code array.

Resolve

const { parsePost, encodePost, MAC_GLYPH_NAMES } = runtime.resolve('tablePost');

API

Method Signature Returns
parsePost (bytes: Uint8Array, numGlyphs?: number) => PostTable numGlyphs required for v2.0.
encodePost (post: PostTable) => Uint8Array Emits the 32-byte header only, whatever post.version — glyph names are never encoded.
MAC_GLYPH_NAMES string[] The 258 standard Mac names (Apple TT Manual / OT spec post v1.0).

PostTable

version: number (decimal, e.g. 2.0), italicAngle, underlinePosition, underlineThickness, isFixedPitch, minMemType42, maxMemType42, minMemType1, maxMemType1, glyphNames?: string[].

Examples

const { parsePost } = runtime.resolve('tablePost');
const post = parsePost(sfnt.tables.post.bytes, maxp.numGlyphs);
console.log(post.version, post.glyphNames?.[42]);

Notes

  • v2.0 throws 'fonts/post-num-mismatch' if the internal numberOfGlyphs differs from maxp.numGlyphs, and 'fonts/post-need-numGlyphs' if numGlyphs was not passed.
  • v2.5 throws 'fonts/post-v2-5-unsupported' — no fallback.
  • Indices ≥ 258 in v2.0 point to the custom pascal strings following the index table.
  • v1.0 also accepts an optional numGlyphs to populate glyphNames (Mac standard names, glyphN beyond 258).
  • v4.0 is recognised but its character-code array is not decoded — treat it as unsupported for glyphNames.

See also

  • maxp — provides numGlyphs
  • fonts — font.getGlyphByIndex reads post.glyphNames[gid] there