Fonts and Shaping

Standard fonts

The 14 standard PDF fonts need no embedding, but only support Latin text (WinAnsi encoding):

import { StandardFonts } from 'happypdf';

const font = await pdfDoc.embedFont(StandardFonts.Helvetica);

For anything else — accents outside Latin-1, or any non-Latin script — embed a font.

Embedding a custom font

const font = await pdfDoc.embedFont(fs.readFileSync('Ubuntu-R.ttf'));

Accepts Uint8Array, ArrayBuffer, or a base64 string. TrueType and OpenType (including CFF) are supported.

Subsetting

const font = await pdfDoc.embedFont(bytes, { subset: true });

Only the glyphs you actually draw are embedded. For a large font used for a little text this is the difference between a 5 MB file and a 30 KB one.

Subsetting happens when the document is saved, so it accounts for every string you drew with that font.

Complex scripts

Nothing special is required — shaping is always on:

const khmer = await pdfDoc.embedFont(
  fs.readFileSync('NotoSansKhmer-Regular.ttf'),
);
page.drawText('សួស្តីពិភពលោក', { font: khmer, x: 50, y: 700, size: 24 });

The same applies to Thai, Lao, Arabic, Devanagari, Tamil and other scripts that need reordering or mark attachment. See the live demo.

OpenType features

const font = await pdfDoc.embedFont(bytes, {
  features: { liga: false, onum: true },
});

Feature tags are passed to HarfBuzz. Set a tag to false to disable a feature that is on by default, or true to enable an optional one.

Variable fonts

variations pins a variable font's axes:

const regular = await pdfDoc.embedFont(bytes, { variations: { wght: 400 } });
const bold = await pdfDoc.embedFont(bytes, { variations: { wght: 700 } });

Each combination produces a separately embedded instance, so use only the ones you need.

Axis ranges

Values are clamped to the axis range declared in the font's fvar table. A font whose wght runs 400–700 will treat { wght: 100 } as 400 — the request is silently clamped, not rejected.

Measuring text

font.widthOfTextAtSize('Hello', 24); // shaped advance width
font.heightAtSize(24); // line height
font.sizeAtHeight(30); // size that yields a given height

Widths come from the shaped run, so kerning and ligatures are accounted for.

Custom font names

const font = await pdfDoc.embedFont(bytes, { customName: 'MyFont' });

Overrides the name written into the PDF, which some workflows rely on for downstream processing.