43 lines
1.0 KiB
JavaScript
43 lines
1.0 KiB
JavaScript
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// Adapted from https://gist.github.com/mjackson/5311256
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function hueToRgb(p, q, t) {
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if (t < 0)
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t += 1;
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if (t > 1)
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t -= 1;
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if (t < 1 / 6)
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return p + (q - p) * 6 * t;
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if (t < 1 / 2)
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return q;
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if (t < 2 / 3)
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return p + (q - p) * (2 / 3 - t) * 6;
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return p;
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}
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function hslaToRgba({ hue, saturation, lightness, alpha }) {
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hue /= 360;
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saturation /= 100;
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lightness /= 100;
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let red = 0;
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let green = 0;
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let blue = 0;
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if (!saturation) {
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red = green = blue = lightness;
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}
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else {
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const q = lightness < 0.5
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? lightness * (1 + saturation)
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: lightness + saturation - lightness * saturation;
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const p = 2 * lightness - q;
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red = hueToRgb(p, q, hue + 1 / 3);
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green = hueToRgb(p, q, hue);
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blue = hueToRgb(p, q, hue - 1 / 3);
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}
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return {
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red: Math.round(red * 255),
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green: Math.round(green * 255),
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blue: Math.round(blue * 255),
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alpha,
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};
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}
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export { hslaToRgba };
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