hexo/node_modules/stylus/lib/functions/adjust.js

31 lines
818 B
JavaScript

var utils = require('../utils');
/**
* Adjust HSL `color` `prop` by `amount`.
*
* @param {RGBA|HSLA} color
* @param {String} prop
* @param {Unit} amount
* @return {RGBA}
* @api private
*/
function adjust(color, prop, amount){
utils.assertColor(color, 'color');
utils.assertString(prop, 'prop');
utils.assertType(amount, 'unit', 'amount');
var hsl = color.hsla.clone();
prop = { hue: 'h', saturation: 's', lightness: 'l' }[prop.string];
if (!prop) throw new Error('invalid adjustment property');
var val = amount.val;
if ('%' == amount.type){
val = 'l' == prop && val > 0
? (100 - hsl[prop]) * val / 100
: hsl[prop] * (val / 100);
}
hsl[prop] += val;
return hsl.rgba;
};
adjust.params = ['color', 'prop', 'amount'];
module.exports = adjust;