@capsizecss/unpack

@capsizecss/unpack

Unpack the capsize font metrics directly from a font file.

npm install @capsizecss/unpack

• Usage
  • fromBuffer
  • fromBlob
  • fromUrl
  • fromFile
• Options
  • postscriptName
• Font Metrics

Usage

fromBuffer

Takes a buffer and returns the resolved font metrics.

import { fromBuffer } from '@capsizecss/unpack';

const metrics = await fromBuffer(buffer);

fromBlob

Takes a file blob and returns the resolved font metrics.

import { fromBlob } from '@capsizecss/unpack';

const metrics = await fromBlob(file);

fromUrl

Takes a url string and returns the resolved font metrics.

import { fromUrl } from '@capsizecss/unpack';

const metrics = await fromUrl(url);

fromFile

Takes a file path string and returns the resolved font metrics.

import { fromFile } from '@capsizecss/unpack';

const metrics = await fromFile(filePath);

Options

All of the above APIs accept an optional second parameter with the following options:

postscriptName

Capsize can extract the metrics for a single font from a TrueType Collection (TTC) file by providing the postscriptName.

import { fromFile } from '@capsizecss/unpack';

const metrics = await fromFile('AvenirNext.ttc', {
  postscriptName: 'AvenirNext-Bold',
});

Font metrics

The font metrics object returned contains the following properties:

Property	Type	Description
familyName	string	The font’s family name as authored by font creator
fullName	string	The font’s full name as authored by font creator
postscriptName	string	The font’s unique PostScript name as authored by font creator
category	string	The style of the font: serif, sans-serif, monospace, display, or handwriting.
capHeight	number	The height of capital letters above the baseline
ascent	number	The height of the ascenders above baseline
descent	number	The descent of the descenders below baseline
lineGap	number	The amount of space included between lines
unitsPerEm	number	The size of the font’s internal coordinate grid
xHeight	number	The height of the main body of lower case letters above baseline
xWidthAvg	number	The average width of character glyphs in the font for the selected unicode subset. Calculated based on character frequencies in written text, falling back to the built in xAvgCharWidth from the OS/2 table.
subsets	{ [subset]: { xWidthAvg: number } }	A lookup of the xWidthAvg metric by subset (see supported subsets)

Thanks

• Devon Govett for creating Fontkit, which does all the heavy lifting of extracting the font metrics under the covers.
• SEEK for giving us the space to do interesting work.

License

MIT.