subdivideLeft method

void subdivideLeft(double t)

Changes this curve in place to be the portion of itself from t, 1. @param {number} t The start of the desired portion of the curve.

Implementation

void subdivideLeft(double t)
{
  if (t == 1) {
    return;
  }

  // Step one - from 4 points to 3
  double ix0 = Algebra.lerp(this.x0, this.x1, t);
  double iy0 = Algebra.lerp(this.y0, this.y1, t);

  double ix1 = Algebra.lerp(this.x1, this.x2, t);
  double iy1 = Algebra.lerp(this.y1, this.y2, t);

  double ix2 = Algebra.lerp(this.x2, this.x3, t);
  double iy2 = Algebra.lerp(this.y2, this.y3, t);

  // Collect our new x1 and y1
  this.x1 = ix0;
  this.y1 = iy0;

  // Step two - from 3 points to 2
  ix0 = Algebra.lerp(ix0, ix1, t);
  iy0 = Algebra.lerp(iy0, iy1, t);

  ix1 = Algebra.lerp(ix1, ix2, t);
  iy1 = Algebra.lerp(iy1, iy2, t);

  // Collect our new x2 and y2
  this.x2 = ix0;
  this.y2 = iy0;

  // Final step - last point
  this.x3 = Algebra.lerp(ix0, ix1, t);
  this.y3 = Algebra.lerp(iy0, iy1, t);
}