awaforge

tableGasp

AGPL-3.0-onlyRelease 2L4

Table gasp — grid-fitting/anti-aliasing per ppem (OT §6.4.18).

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

Indicates, for each ppem slice, how the rasteriser should handle hinting and smoothing. Version 0 or 1, format { rangeMaxPPEM, rangeGaspBehavior }.

Exports

Symbol Type Description
GASP_FLAG const Bitfield { GRIDFIT, DOGRAY, SYMMETRIC_GRIDFIT, SYMMETRIC_SMOOTHING }.
parseGasp function (bytes) => { version, ranges: Range[] }.
tableGasp factory Factory { name, dependencies, 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 { parseGasp, GASP_FLAG } = fw.runtime.resolve('tableGasp');
const gasp = parseGasp(sfnt.tables.gasp.bytes);
const useGridfit = gasp.ranges[0].rangeGaspBehavior & GASP_FLAG.GRIDFIT;

Notes

  • rangeMaxPPEM = 0xFFFF marks the last range (catch-all).
  • Version 1 adds SYMMETRIC_*; unknown bits are preserved.

See also