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4 years ago
/* MIT license */
var colorNames = require('color-name');
var swizzle = require('simple-swizzle');
var reverseNames = {};
// create a list of reverse color names
for (var name in colorNames) {
if (colorNames.hasOwnProperty(name)) {
reverseNames[colorNames[name]] = name;
}
}
var cs = module.exports = {
to: {},
get: {}
};
cs.get = function (string) {
var prefix = string.substring(0, 3).toLowerCase();
var val;
var model;
switch (prefix) {
case 'hsl':
val = cs.get.hsl(string);
model = 'hsl';
break;
case 'hwb':
val = cs.get.hwb(string);
model = 'hwb';
break;
default:
val = cs.get.rgb(string);
model = 'rgb';
break;
}
if (!val) {
return null;
}
return {model: model, value: val};
};
cs.get.rgb = function (string) {
if (!string) {
return null;
}
var abbr = /^#([a-f0-9]{3,4})$/i;
var hex = /^#([a-f0-9]{6})([a-f0-9]{2})?$/i;
var rgba = /^rgba?\(\s*([+-]?\d+)\s*,\s*([+-]?\d+)\s*,\s*([+-]?\d+)\s*(?:,\s*([+-]?[\d\.]+)\s*)?\)$/;
var per = /^rgba?\(\s*([+-]?[\d\.]+)\%\s*,\s*([+-]?[\d\.]+)\%\s*,\s*([+-]?[\d\.]+)\%\s*(?:,\s*([+-]?[\d\.]+)\s*)?\)$/;
var keyword = /(\D+)/;
var rgb = [0, 0, 0, 1];
var match;
var i;
var hexAlpha;
if (match = string.match(hex)) {
hexAlpha = match[2];
match = match[1];
for (i = 0; i < 3; i++) {
// https://jsperf.com/slice-vs-substr-vs-substring-methods-long-string/19
var i2 = i * 2;
rgb[i] = parseInt(match.slice(i2, i2 + 2), 16);
}
if (hexAlpha) {
rgb[3] = Math.round((parseInt(hexAlpha, 16) / 255) * 100) / 100;
}
} else if (match = string.match(abbr)) {
match = match[1];
hexAlpha = match[3];
for (i = 0; i < 3; i++) {
rgb[i] = parseInt(match[i] + match[i], 16);
}
if (hexAlpha) {
rgb[3] = Math.round((parseInt(hexAlpha + hexAlpha, 16) / 255) * 100) / 100;
}
} else if (match = string.match(rgba)) {
for (i = 0; i < 3; i++) {
rgb[i] = parseInt(match[i + 1], 0);
}
if (match[4]) {
rgb[3] = parseFloat(match[4]);
}
} else if (match = string.match(per)) {
for (i = 0; i < 3; i++) {
rgb[i] = Math.round(parseFloat(match[i + 1]) * 2.55);
}
if (match[4]) {
rgb[3] = parseFloat(match[4]);
}
} else if (match = string.match(keyword)) {
if (match[1] === 'transparent') {
return [0, 0, 0, 0];
}
rgb = colorNames[match[1]];
if (!rgb) {
return null;
}
rgb[3] = 1;
return rgb;
} else {
return null;
}
for (i = 0; i < 3; i++) {
rgb[i] = clamp(rgb[i], 0, 255);
}
rgb[3] = clamp(rgb[3], 0, 1);
return rgb;
};
cs.get.hsl = function (string) {
if (!string) {
return null;
}
var hsl = /^hsla?\(\s*([+-]?(?:\d*\.)?\d+)(?:deg)?\s*,\s*([+-]?[\d\.]+)%\s*,\s*([+-]?[\d\.]+)%\s*(?:,\s*([+-]?[\d\.]+)\s*)?\)$/;
var match = string.match(hsl);
if (match) {
var alpha = parseFloat(match[4]);
var h = (parseFloat(match[1]) + 360) % 360;
var s = clamp(parseFloat(match[2]), 0, 100);
var l = clamp(parseFloat(match[3]), 0, 100);
var a = clamp(isNaN(alpha) ? 1 : alpha, 0, 1);
return [h, s, l, a];
}
return null;
};
cs.get.hwb = function (string) {
if (!string) {
return null;
}
var hwb = /^hwb\(\s*([+-]?\d*[\.]?\d+)(?:deg)?\s*,\s*([+-]?[\d\.]+)%\s*,\s*([+-]?[\d\.]+)%\s*(?:,\s*([+-]?[\d\.]+)\s*)?\)$/;
var match = string.match(hwb);
if (match) {
var alpha = parseFloat(match[4]);
var h = ((parseFloat(match[1]) % 360) + 360) % 360;
var w = clamp(parseFloat(match[2]), 0, 100);
var b = clamp(parseFloat(match[3]), 0, 100);
var a = clamp(isNaN(alpha) ? 1 : alpha, 0, 1);
return [h, w, b, a];
}
return null;
};
cs.to.hex = function () {
var rgba = swizzle(arguments);
return (
'#' +
hexDouble(rgba[0]) +
hexDouble(rgba[1]) +
hexDouble(rgba[2]) +
(rgba[3] < 1
? (hexDouble(Math.round(rgba[3] * 255)))
: '')
);
};
cs.to.rgb = function () {
var rgba = swizzle(arguments);
return rgba.length < 4 || rgba[3] === 1
? 'rgb(' + Math.round(rgba[0]) + ', ' + Math.round(rgba[1]) + ', ' + Math.round(rgba[2]) + ')'
: 'rgba(' + Math.round(rgba[0]) + ', ' + Math.round(rgba[1]) + ', ' + Math.round(rgba[2]) + ', ' + rgba[3] + ')';
};
cs.to.rgb.percent = function () {
var rgba = swizzle(arguments);
var r = Math.round(rgba[0] / 255 * 100);
var g = Math.round(rgba[1] / 255 * 100);
var b = Math.round(rgba[2] / 255 * 100);
return rgba.length < 4 || rgba[3] === 1
? 'rgb(' + r + '%, ' + g + '%, ' + b + '%)'
: 'rgba(' + r + '%, ' + g + '%, ' + b + '%, ' + rgba[3] + ')';
};
cs.to.hsl = function () {
var hsla = swizzle(arguments);
return hsla.length < 4 || hsla[3] === 1
? 'hsl(' + hsla[0] + ', ' + hsla[1] + '%, ' + hsla[2] + '%)'
: 'hsla(' + hsla[0] + ', ' + hsla[1] + '%, ' + hsla[2] + '%, ' + hsla[3] + ')';
};
// hwb is a bit different than rgb(a) & hsl(a) since there is no alpha specific syntax
// (hwb have alpha optional & 1 is default value)
cs.to.hwb = function () {
var hwba = swizzle(arguments);
var a = '';
if (hwba.length >= 4 && hwba[3] !== 1) {
a = ', ' + hwba[3];
}
return 'hwb(' + hwba[0] + ', ' + hwba[1] + '%, ' + hwba[2] + '%' + a + ')';
};
cs.to.keyword = function (rgb) {
return reverseNames[rgb.slice(0, 3)];
};
// helpers
function clamp(num, min, max) {
return Math.min(Math.max(min, num), max);
}
function hexDouble(num) {
var str = num.toString(16).toUpperCase();
return (str.length < 2) ? '0' + str : str;
}