split method

(Cubic, Cubic) split(double t)

Returns two Cubics, created by splitting this curve at the given distance of t between the original starting and ending anchor points.

Implementation

(Cubic, Cubic) split(double t) {
  // Cartesian optimization via the De Casteljau's algorithm.

  // Use barycentric interpolation.
  final u = 1.0 - t;

  // Interpolation 1.
  final p01X = anchor0X * u + control0X * t;
  final p01Y = anchor0Y * u + control0Y * t;

  final p12X = control0X * u + control1X * t;
  final p12Y = control0Y * u + control1Y * t;

  final p23X = control1X * u + anchor1X * t;
  final p23Y = control1Y * u + anchor1Y * t;

  // Interpolation 2.
  final p012X = p01X * u + p12X * t;
  final p012Y = p01Y * u + p12Y * t;

  final p123X = p12X * u + p23X * t;
  final p123Y = p12Y * u + p23Y * t;

  // Interpolation 3.
  final p0123X = p012X * u + p123X * t;
  final p0123Y = p012Y * u + p123Y * t;

  return (
    .from(anchor0X, anchor0Y, p01X, p01Y, p012X, p012Y, p0123X, p0123Y),
    .from(p0123X, p0123Y, p123X, p123Y, p23X, p23Y, anchor1X, anchor1Y),
  );
}