font-measure

font-measure

Calculate metrics for a font.

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(font, options?)

Get metrics data for a font, 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.
size	64	Font-size to use for calculations. Larger size gives higher precision with slower performance.
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.

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.

License

© 2018 Dima Yv. MIT License

Development supported by plot.ly.