mirror of https://github.com/thangisme/notes.git
31 lines
1.3 KiB
JavaScript
31 lines
1.3 KiB
JavaScript
module.exports = function CMYK(color) {
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color.installColorSpace('CMYK', ['cyan', 'magenta', 'yellow', 'black', 'alpha'], {
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rgb: function () {
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return new color.RGB((1 - this._cyan * (1 - this._black) - this._black),
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(1 - this._magenta * (1 - this._black) - this._black),
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(1 - this._yellow * (1 - this._black) - this._black),
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this._alpha);
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},
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fromRgb: function () { // Becomes one.color.RGB.prototype.cmyk
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// Adapted from http://www.javascripter.net/faq/rgb2cmyk.htm
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var red = this._red,
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green = this._green,
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blue = this._blue,
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cyan = 1 - red,
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magenta = 1 - green,
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yellow = 1 - blue,
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black = 1;
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if (red || green || blue) {
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black = Math.min(cyan, Math.min(magenta, yellow));
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cyan = (cyan - black) / (1 - black);
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magenta = (magenta - black) / (1 - black);
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yellow = (yellow - black) / (1 - black);
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} else {
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black = 1;
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}
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return new color.CMYK(cyan, magenta, yellow, black, this._alpha);
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}
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});
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};
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