@thi.ng/geom-splines/quadratic-split.js

nD cubic & quadratic curve analysis, conversion, interpolation, splitting

import { minError } from "@thi.ng/math/min-error";
import { distSq } from "@thi.ng/vectors/distsq";
import { mixQuadratic } from "@thi.ng/vectors/mix-quadratic";
import { mixN } from "@thi.ng/vectors/mixn";
import { set } from "@thi.ng/vectors/set";
const quadraticSplitAt = (a, b, c, t) => {
  if (t <= 0 || t >= 1) {
    const p2 = t <= 0 ? a : c;
    const c1 = [set([], p2), set([], p2), set([], p2)];
    const c2 = [set([], a), set([], b), set([], c)];
    return t <= 0 ? [c1, c2] : [c2, c1];
  }
  const ab = mixN([], a, b, t);
  const bc = mixN([], b, c, t);
  const p = mixN([], ab, bc, t);
  return [
    [set([], a), ab, p],
    [p, bc, set([], c)]
  ];
};
const quadraticSplitNearPoint = (p, a, b, c, res, iter) => quadraticSplitAt(
  a,
  b,
  c,
  minError(
    (t) => mixQuadratic([], a, b, c, t),
    distSq,
    p,
    res,
    iter
  )
);
export {
  quadraticSplitAt,
  quadraticSplitNearPoint
};