34 lines
1.1 KiB
Plaintext
34 lines
1.1 KiB
Plaintext
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// The `ltag` table stores IETF BCP-47 language tags. It allows supporting
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// languages for which TrueType does not assign a numeric code.
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// https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6ltag.html
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// http://www.w3.org/International/articles/language-tags/
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// http://www.iana.org/assignments/language-subtag-registry/language-subtag-registry
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import check from '../check';
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import parse from '../parse';
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function parseLtagTable(data, start) {
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const p = new parse.Parser(data, start);
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const tableVersion = p.parseULong();
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check.argument(tableVersion === 1, 'Unsupported ltag table version.');
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// The 'ltag' specification does not define any flags; skip the field.
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p.skip('uLong', 1);
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const numTags = p.parseULong();
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const tags = [];
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for (let i = 0; i < numTags; i++) {
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let tag = '';
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const offset = start + p.parseUShort();
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const length = p.parseUShort();
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for (let j = offset; j < offset + length; ++j) {
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tag += String.fromCharCode(data.getInt8(j));
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}
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tags.push(tag);
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}
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return tags;
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}
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export default { parse: parseLtagTable };
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