How to create a Bspline Segment parameterized in [0,1]

Hi Friends,

When I segment a bspline the parameters are not updated in range [0,1], how can I do that?

This is my code:

// This creates a long Bspline (firstParameter = 0.0, lastParameter = 1.0)
auto bspl = occt::makeBsplineByPointsApprox(pnts);

// Then I want only one segment
bspl->Segment(0.0, 0.5);

The problem is that the curve is the same but LastParameter is now 0.5
what I need is a new curve segment, parameterized from 0.0 to 1.0 on its own.

Any advice is appreciated.