nearest.js•703 B
import { differenceEuclidean } from './difference.js';
/*
This works linearly right now, but we might get better performance
with a V-P Tree (Vantage Point Tree).
Reference:
* http://pnylab.com/papers/vptree/main.html
*/
const nearest = (colors, metric = differenceEuclidean(), accessor = d => d) => {
let arr = colors.map((c, idx) => ({ color: accessor(c), i: idx }));
return (color, n = 1, τ = Infinity) => {
if (isFinite(n)) {
n = Math.max(1, Math.min(n, arr.length - 1));
}
arr.forEach(c => {
c.d = metric(color, c.color);
});
return arr
.sort((a, b) => a.d - b.d)
.slice(0, n)
.filter(c => c.d < τ)
.map(c => colors[c.i]);
};
};
export default nearest;