如前所述
here
,根据覆盖范围记录计算第一个字符。
let leadingCharacters = [];
subTable.coverage.rangeRecords.forEach((coverage) => {
for (let i = coverage.start; i <= coverage.end; i++) {
let character = font.stringsForGlyph(i)[0];
leadingCharacters.push(character);
}
});
然后,通过子表的索引访问这些字符
let ligatureSets = subTable.ligatureSets.toArray();
ligatureSets.forEach((ligatureSet, ligatureSetIndex) => {
let leadingCharacter = leadingCharacters[ligatureSetIndex];
ligatureSet.forEach(ligature => {
let character = font.stringsForGlyph(ligature.glyph)[0];
let characterCode = character.charCodeAt(0).toString(16).toUpperCase();
let ligatureText = ligature
.components
.map(x => font.stringsForGlyph(x)[0])
.join('');
ligatureText = leadingCharacter + ligatureText;
console.log(`${ligatureText} -> ${characterCode}`);
});
});