The techniques presented in the paper could be extended to handle more complex vector graphics primitives by adapting the error metrics and approximation methods to suit the specific characteristics of elliptical arcs or parametric curves. For elliptical arcs, the error metric for flattening could be modified to account for the unique curvature properties of ellipses. The approximation of parallel curves for elliptical arcs could involve fitting circular arcs to segments of the ellipse and adjusting the error metric accordingly.
When it comes to parametric curves, the conversion from cubic Béziers to Euler spirals could be generalized to handle a wider range of curve types. This may involve developing new interpolation techniques or error metrics that are tailored to the specific properties of parametric curves. Additionally, the algorithm could be enhanced to support different types of parametric curves, such as splines or Bezier curves, by adjusting the control point calculations and curve fitting methods.