/* Convert between Lab and XYZ
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/* ========================================================================== */
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export function lab2lch(labL, labA, labB) {
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const [ lchC, lchH ] = [
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Math.sqrt(Math.pow(labA, 2) + Math.pow(labB, 2)), // convert to chroma
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Math.atan2(labB, labA) * 180 / Math.PI // convert to hue, in degrees
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];
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return [ labL, lchC, lchH ];
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}
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export function lch2lab(lchL, lchC, lchH) {
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// convert to Lab a and b from the polar form
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const [ labA, labB ] = [
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lchC * Math.cos(lchH * Math.PI / 180),
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lchC * Math.sin(lchH * Math.PI / 180)
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];
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return [ lchL, labA, labB ];
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}
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/*
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References
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----------
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- https://www.w3.org/TR/css-color-4/#lch-to-lab
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- https://www.w3.org/TR/css-color-4/#color-conversion-code
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/* ========================================================================== */
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