copy method
Copies another name
object to this instance.
Implementation
@override
QuadraticBezierCurve copy(Curve source) {
if(source is QuadraticBezierCurve){
super.copy(source);
v0.setFrom(source.v0);
v1.setFrom(source.v1);
v2.setFrom(source.v2);
}
return this;
}