Creates a new curve, formed by the points with parameterization:
p(t) = c(t) + d*n(t)/|n(t)|, with p(t) being a point of
the original curve, n(t) the normal of the curve, and |n| being the
norm of n.
A PolyCurve2D is a set of piecewise smooth curve arcs, such that the end of a
curve is the beginning of the next curve, and such that they do not intersect
nor self-intersect.
A PolyOrientedCurve2D is a set of piecewise smooth curve arcs, such that the
end of a curve is the beginning of the next curve, and such that they do not
intersect nor self-intersect.