thelonious / kld-polynomial Goto Github PK

I subdivided a cubic bezier and created the two following cubic beziers:

const a = [
  { x: 162.48848597698444, y: 112.35319657757165 },
  { x: 163.95162031178776, y: 116.41373265436673 },
  { x: 165.52010700334841, y: 120.60494234401577 },
  { x: 167.20635691757136, y: 124.93096260181979 },
];

const b = [
  { x: 167.20635691757136, y: 124.93096260181979 },
  { x: 171.54020965581395, y: 136.04932328005688 },
  { x: 176.651945072729, y: 148.0581725463195 },
  { x: 182.75226034297538, y: 161.02774279216203 },
];

Running these beziers through intersectBezier3Bezier3 will produce this Polynomial.

var poly = new Polynomial(
  8.282089296964086e-38,
  1.3395768780405303e-26,
  7.222276683850399e-16,
  1.4410533333746558e-14,
  1.4180955129790285e-13,
  4.0776756971006023e-13,
  -1.3752193828153736e-13,
  -7.466249840604178e-14,
  -6.794564910705958e-14,
  -4.551914400963142e-15,
);

Calling poly.simplify() will result in a polynomial with the coefs being an empty array.

I'm not going to pretend to understand the math behind Polynomials, but in 61e809c, an empty Polynomial is referred to as unexpected. What makes an empty Polynomial unexpected?

I consistently run into this issue when intersecting different beziers that are the result of a bezier subdivision, but haven't seen this happen under any other circumstances.

Workaround

My current workaround this issue is:

var droots = this.getDegree() > 0
  ? deriv.getRootsInInterval(min, max)
  : [];

https://npmjs.org/doc/misc/npm-disputes.html

Don't squat on package names. Publish code or move out of the way.

Putting empty packages in the registry. Packages must have SOME functionality. It can be silly, but it can't be nothing. (See also: squatting.)

I was wondering why result is here:

svg-intersections depends on zeroErrorEstimate and it's not in the version there.

Thanks!