How to extract spline in a .dwg file and draw it using lines? Is there a way to do it other that vectorize?

Check virtual OdResult OdDbCurve::getOdGeCurve ( OdGeCurve3d*& pGeCurve, const OdGeTol& tol = OdGeContext::gTol ) const;
use pGeCurve->getSamplePoints(...) and delete OdDbCurve;