dotfiles/bin/color.js
2012-12-26 10:07:30 +04:00

111 lines
2.2 KiB
JavaScript
Executable File

#!/usr/bin/env node
/**
* HTML color converter
* Convert #hex colors to HSL/HSLA (by default) or RGB/RGBA (if `--rgb` key specified).
*
* Usage: color [--rgb] [#]dead00 [alpha]
*
* Author: Artem Sapegin, sapegin.me
* Based on https://github.com/LeaVerou/CSS.coloratum
*/
//jshint node:true
var format = 'hsl';
var args = process.argv.splice(2);
if (!args.length) helpme();
if (args[0] === '--rgb') {
format = 'rgb';
args = args.splice(1);
}
if (!args.length) helpme();
var rgb = hex2rgb(args[0]);
if (!rgb) helpme();
var alpha = args[1];
if (format === 'hsl') {
console.log(toHslString(rgb2hsl(rgb), alpha));
}
else {
console.log(toRgbString(rgb, alpha));
}
function helpme() {
console.log('Usage: color [--rgb] [#]dead00 [alpha]');
process.exit(1);
}
function hex2rgb(rgbString) {
// Remove leading `#`
rgbString = rgbString.replace(/^#/, '');
// Parse `dead00` and `f00`
var channels = [];
if (rgbString.length === 3) {
channels = rgbString.match(/([0-9a-f])/ig);
channels = channels.map(function(hex) {
return hex + hex;
});
}
else {
channels = rgbString.match(/([0-9a-f]){2}/ig);
}
if (channels.length !== 3) {
return null;
}
// Convert to integers
channels = channels.map(function(hex) {
return parseInt(hex, 16);
});
return channels;
}
function rgb2hsl(rgb) {
rgb = rgb.map(function(a) {
return a / 2.55;
});
var hsl = [];
var max = Math.max.apply(Math, rgb);
var min = Math.min.apply(Math, rgb);
hsl[2] = Math.round((min + max)/2);
var d = max - min;
if(d !== 0) {
hsl[1] = Math.round(d*100 / (100 - Math.abs(2*hsl[2] - 100))) + '%';
switch(max){
case rgb[0]: hsl[0] = (rgb[1] - rgb[2]) / d + (rgb[1] < rgb[2] ? 6 : 0); break;
case rgb[1]: hsl[0] = (rgb[2] - rgb[0]) / d + 2; break;
case rgb[2]: hsl[0] = (rgb[0] - rgb[1]) / d + 4;
}
hsl[0] = Math.round(hsl[0]*60);
}
else {
hsl[0] = 0;
hsl[1] = '0%';
}
hsl[2] += '%';
return hsl;
}
function toRgbString(rgb, alpha) {
return 'rgb' + (alpha < 1 ? 'a' : '') + '(' + rgb.join(',') + ((alpha < 1 ? ',' + alpha : '') + ')').replace(/\b0\./, '.');
}
function toHslString(hsl, alpha) {
return 'hsl' + (alpha < 1 ? 'a' : '') + '(' + hsl.join(',') + ((alpha < 1 ? ',' + alpha : '') + ')').replace(/\b0\./, '.');
}