23 lines
485 B
JavaScript
23 lines
485 B
JavaScript
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import converter from './converter.js';
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/*
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WCAG luminance
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References:
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https://en.wikipedia.org/wiki/Relative_luminance
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https://github.com/w3c/wcag/issues/236#issuecomment-379526596
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*/
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export function luminance(color) {
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let c = converter('lrgb')(color);
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return 0.2126 * c.r + 0.7152 * c.g + 0.0722 * c.b;
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}
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/*
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WCAG contrast
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*/
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export function contrast(a, b) {
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let L1 = luminance(a);
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let L2 = luminance(b);
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return (Math.max(L1, L2) + 0.05) / (Math.min(L1, L2) + 0.05);
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}
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