Cubic constructor Null safety
Creates a cubic curve.
Rather than creating a new instance, consider using one of the common cubic curves in Curves.
The a (x1), b (y1), c (x2) and d (y2) arguments must not be null.
Implementation
const Cubic(this.a, this.b, this.c, this.d)
: assert(a != null),
assert(b != null),
assert(c != null),
assert(d != null);