normalAt method
The normal vector of the curve at parameter value t
.
The return value is normalized. See derivativeAt for information about
the optional parameter cachedFirstOrderDerivativePoints
.
Implementation
Vector2 normalAt(double t,
{List<Vector2>? cachedFirstOrderDerivativePoints}) {
final d = derivativeAt(t,
cachedFirstOrderDerivativePoints: cachedFirstOrderDerivativePoints)
..normalize();
return Vector2(-d.y, d.x);
}