Function getTatLen

libraries/p5.js:30221–30233

(x1, y1, x2, y2, x3, y3, x4, y4, ll)

}

function getTatLen(x1, y1, x2, y2, x3, y3, x4, y4, ll) {
  if (ll < 0 || bezlen(x1, y1, x2, y2, x3, y3, x4, y4) < ll) {
    return;
  }
  var t = 1, step = t / 2, t2 = t - step, l, e = 0.01;
  l = bezlen(x1, y1, x2, y2, x3, y3, x4, y4, t2);
  while (Math.abs(l - ll) > e) {
    step /= 2;
    t2 += (l < ll ? 1 : -1) * step;
    l = bezlen(x1, y1, x2, y2, x3, y3, x4, y4, t2);
  }
  return t2;
}

function base3(t, p1, p2, p3, p4) {
  var t1 = -3 * p1 + 9 * p2 - 9 * p3 + 3 * p4,