awaforge

tableHvar

AGPL-3.0-onlyRelease 2L4

Table HVAR — Horizontal Metrics Variations (OT §10.6.6).

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

Deltas to apply to hmtx.advanceWidth / lsb / rsb depending on axis location. The ItemVariationStore table (deltas shared per region) is kept as raw bytes and not decoded.

Exports

Symbol Type Description
parseHvar function (bytes) => { majorVersion, minorVersion, itemVariationStoreOffset, advanceWidthMappingOffset, lsbMappingOffset, rsbMappingOffset, itemVariationStoreBytes }.
tableHvar factory Factory.

Usage

import fw from '@awacloud/fw';
import { fw_require, modules } from '@awacloud/fonts';

for (const m of [...fw_require, ...modules]) fw.runtime.register(m);
const { parseHvar } = fw.runtime.resolve('tableHvar');
const hvar = parseHvar(sfnt.tables.HVAR.bytes);

Notes

  • If a mapping offset is 0, the delta-set index is directly the glyph ID.
  • The ItemVariationStore is not decoded: only its raw bytes (itemVariationStoreBytes) are returned, so applying the deltas is up to the caller.

See also