typerules/lib/_functions.styl

A typography toolkit that sets vertical rhythm and provides type functions.

/* REM function */
// Convert pixel units to rem units

rem($pixels)
  (floor($pixels/$base-font-size, 10))rem


// True if a number has a relative unit.
check-unit(number)
  if (unit(number) is 'px')
    warn('relative-font-sizing is false but a relative font size was passed to the rhythm function')

// Calculates rhythm units.
calculates-rhythm-units($lines = 1, $offset = 0)
  if (not $relative-font-sizing) and ($font-size is not $base-font-size)
    warn('relative-font-sizing is false but a relative font size was passed to the rhythm function')
  return rem($lines * $base-line-height - $offset)

// Calculates the minimum multiple of rhythm units needed to contain the font-size.
lines-for-font-size($font-size)
  $lines = $round-to-nearest-half-line ? ceil(2 * $font-size / $base-line-height) / 2 : ceil($font-size / $base-line-height)
  if $lines * $base-line-height - $font-size < $min-line-padding * 2
    $lines = $lines + ($round-to-nearest-half-line ? 0.5 : 1)
  return unit($lines, '')