awaforge

pdfType3

AGPL-3.0-onlyRelease 2L4

Typing of a Type 3 font (glyphs defined by content streams) — ISO 32000-2 §9.6.4.

Module pdfType3 | Source packages/front/office/pdf/src/font/type3.js | Deps pdfErrors, pdfParser | Worker-safe yes

Unlike Type1/TrueType/CIDFont (which delegate to @awacloud/fonts), Type 3 fonts are PDF-specific: each glyph is defined by a content stream in /CharProcs. That is why this module lives here rather than in @awacloud/fonts. The exposed record carries bbox, matrix (defaults to [0.001, 0, 0, 0.001, 0, 0]), charProcs, encoding, firstChar/lastChar/widths, fontDescriptor (optional in PDF 2.0), and resources (local to the glyphs).

Resolve

const t3 = runtime.resolve('pdfType3');
// Returns: { typeType3 }

API

Method Signature Returns
typeType3 (dict) => Type3Font Typing.

Shape Type3Font

{
    subtype: 'Type3',
    bbox:   [llx,lly,urx,ury] | null,
    matrix: [0.001,0,0,0.001,0,0],   // default
    charProcs:      { [glyphName]: PdfObject },   // stream | ref
    encoding:       PdfObject | null,
    firstChar:      int | null,
    lastChar:       int | null,
    widths:         number[] | null,
    fontDescriptor: PdfObject | null,
    resources:      PdfObject | null,
    raw:            object
}

Examples

Typing

const t3 = runtime.resolve('pdfType3');
const font = t3.typeType3(resources.Font.F1);
font.subtype;     // 'Type3'
font.bbox;        // [0, 0, 1000, 1000]
font.matrix;      // [0.001, 0, 0, 0.001, 0, 0]

Rendering a glyph stream

const procRef = font.charProcs.a;     // ref to a content stream
const proc = doc._raw.resolve(procRef);
const ops = runtime.resolve('pdfContentStream').parseContentStream(proc.raw);
// The first op is usually d0 or d1 (set glyph metrics)

Encoding via the dedicated module

const enc = runtime.resolve('pdfFontEncoding');
const table = enc.resolveEncoding(font.encoding, lookupNamed);

Errors

Code Class When
pdf/type3/not-dict ParseError Argument is not a typed dict.
pdf/type3/wrong-subtype ParseError /Subtype absent, not a name, or ≠ /Type3.

See also