assets/sass/bourbon/bourbon/utilities/_contrast-ratio.scss

   1 @charset "UTF-8";
   2
   3 /// Programatically determines the contrast ratio between two colors.
   4 ///
   5 /// Note that the alpha channel is ignored.
   6 ///
   7 /// @link https://goo.gl/54htLV
   8 ///
   9 /// @argument {color (hex)} $color-1
  10 ///
  11 /// @argument {color (hex)} $color-2
  12 ///
  13 /// @return {number (1-21)}
  14 ///
  15 /// @example scss
  16 ///   _contrast-ratio(black, white)
  17 ///
  18 /// @require {function} _lightness
  19 ///
  20 /// @access private
  21
  22 @function _contrast-ratio($color-1, $color-2) {
  23   $-local-lightness-1: _lightness($color-1) + 0.05;
  24   $-local-lightness-2: _lightness($color-2) + 0.05;
  25
  26   @if $-local-lightness-1 > $-local-lightness-2 {
  27     @return $-local-lightness-1 / $-local-lightness-2;
  28   } @else {
  29     @return $-local-lightness-2 / $-local-lightness-1;
  30   }
  31 }