awaforge

fontFixed

AGPL-3.0-onlyRelease 2L4

Fixed-point numeric helpers for OpenType — 16.16, F2Dot14, version16Dot16.

Module fontFixed | Source packages/front/office/fonts/src/primitives/fixed.js | Deps none | Worker-safe yes

Fixed-point encoded values used throughout OpenType. All represented as JS Number (no bigint) — 16.16 stays well under Number.MAX_SAFE_INTEGER.

Resolve

const { fixedFromInt32, fixedToInt32,
        f2dot14FromInt16, f2dot14ToInt16,
        decodeVersion16Dot16, encodeVersion16Dot16 } = runtime.resolve('fontFixed');

API

Method Signature Returns
fixedFromInt32 (i: number) => number Decodes a BE int32 into a Fixed 16.16.
fixedToInt32 (v: number) => number Encodes a Fixed 16.16 into an int32 (32-bit signed).
f2dot14FromInt16 (i: number) => number Decodes an int16 into F2Dot14.
f2dot14ToInt16 (v: number) => number Encodes an F2Dot14 — saturated to [-32768, 32767].
decodeVersion16Dot16 (i: number) => { major, minor } Splits a raw version16Dot16 value.
encodeVersion16Dot16 (major, minor) => number Inverse of decodeVersion16Dot16.

JS ↔ binary mapping

OT type Bytes JS via
Fixed (16.16) 4 int32 / 65536
F2Dot14 2 int16 / 16384
version16Dot16 4 { major: hi16, minor: lo16 } (never arithmetic)

Examples

16.16

const f = runtime.resolve('fontFixed');
f.fixedFromInt32(0x00010000);  // 1.0
f.fixedToInt32(1.5);           // 0x00018000

version16Dot16

f.decodeVersion16Dot16(0x00010000);  // { major: 1, minor: 0 }

Notes

  • version16Dot16 must NEVER be treated as an arithmetic number — use decodeVersion16Dot16.
  • f2dot14ToInt16 is saturating: values outside [-2, 2) are clamped without throwing.

See also