### Compute a point on power basis curve
### The NURBS book p. 7
sub new {
my $class = shift;
$self = SUPER::new->(@_);
}
sub calculate {
my ($self, @a, $n, $u0, $C) = @_;
$C = @a[$n];
for (my $i = $n - 1; $i >= 0; $i--) {
$C = $C * $u0 + @a[$i];
}
return $C;
}