lib-font/src/opentype/tables/simple/OS2.js

A JS based OpenType font inspector

import { SimpleTable } from "../simple-table.js";

/**
 * The OpenType `OS/2` table.
 *
 * See https://docs.microsoft.com/en-us/typography/opentype/spec/OS2
 */
class OS2 extends SimpleTable {
  constructor(dict, dataview) {
    const { p } = super(dict, dataview);

    this.version = p.uint16;
    this.xAvgCharWidth = p.int16;
    this.usWeightClass = p.uint16;
    this.usWidthClass = p.uint16;
    this.fsType = p.uint16;
    this.ySubscriptXSize = p.int16;
    this.ySubscriptYSize = p.int16;
    this.ySubscriptXOffset = p.int16;
    this.ySubscriptYOffset = p.int16;
    this.ySuperscriptXSize = p.int16;
    this.ySuperscriptYSize = p.int16;
    this.ySuperscriptXOffset = p.int16;
    this.ySuperscriptYOffset = p.int16;
    this.yStrikeoutSize = p.int16;
    this.yStrikeoutPosition = p.int16;
    this.sFamilyClass = p.int16;
    this.panose = [...new Array(10)].map((_) => p.uint8);
    this.ulUnicodeRange1 = p.flags(32);
    this.ulUnicodeRange2 = p.flags(32);
    this.ulUnicodeRange3 = p.flags(32);
    this.ulUnicodeRange4 = p.flags(32);
    this.achVendID = p.tag;
    this.fsSelection = p.uint16;
    this.usFirstCharIndex = p.uint16;
    this.usLastCharIndex = p.uint16;
    this.sTypoAscender = p.int16;
    this.sTypoDescender = p.int16;
    this.sTypoLineGap = p.int16;
    this.usWinAscent = p.uint16;
    this.usWinDescent = p.uint16;

    if (this.version === 0) return p.verifyLength();

    this.ulCodePageRange1 = p.flags(32);
    this.ulCodePageRange2 = p.flags(32);

    if (this.version === 1) return p.verifyLength();

    this.sxHeight = p.int16;
    this.sCapHeight = p.int16;
    this.usDefaultChar = p.uint16;
    this.usBreakChar = p.uint16;
    this.usMaxContext = p.uint16;

    if (this.version <= 4) return p.verifyLength();

    this.usLowerOpticalPointSize = p.uint16;
    this.usUpperOpticalPointSize = p.uint16;

    if (this.version === 5) return p.verifyLength();
  }
}

export { OS2 };