node-font-measure

node-font-measure

Calculate metrics for a font in NodeJS.

let measure = requrie('font-measure')

measure('Roboto')

/*
{
  top: 0,
  median: 0.640625,
  middle: 0.640625,
  bottom: 1.3125,
  alphabetic: 1.03125,
  baseline: 1.03125,
  upper: 0.328125,
  lower: 0.515625,
  capHeight: 0.703125,
  xHeight: 0.515625
  ascent: 0.28125,
  descent: 1.234375,
  hanging: 0.203125,
  ideographic: 1.296875,
  lineHeight: 1.3125,
  overshoot: 0.015625,
  tittle: 0.28125,
}
 */

API

let metrics = measure(family, options?)

Get metrics data for a font family or CSS font string, possibly with custom options. Font can be a string or an array with fonts.

metrics:

options:

Property	Default	Meaning
origin	top	Origin for metrics. Can be changed to baseline or any other metric.
fontSize	64	Font-size to use for calculations. Larger size gives higher precision with slower performance.
fontWeight	normal	Font weight to use for calculations, eg. bold, 700 etc.
fontStyle	normal	Font style to use for calculations, eg. italic, oblique.
canvas	measure.canvas	Canvas to use for measurements.
tittle	i	Character to detect tittle. null disables calculation.
descent	p	Character to detect descent line. null disables calculation.
ascent	h	Character to detect ascent line. null disables calculation.
overshoot	O	Character to detect overshoot. null disables calculation.
upper	H	Character to detect upper line / cap-height. null disables calculation.
lower	x	Character to detect lower line / x-height. null disables calculation.
text	mmmmmmmmmmlli	String to meaureText

See also

• optical-properties − calculate image/character optical center and bounding box.
• detect-kerning − calculate kerning pairs for a font.

Related

There are many text / font measuring packages for the moment, but most of them don't satisfy basic quality requirements. Special thanks to @soulwire for fontmetrics as model implementation.