Create a smooth blend curve connecting the end of one guide curve to the start of another, with custom bulge factors.

Input parameters:

1. C1 → Guide curve for the start of the blend curve.
2. C2 → Guide curve for the end of the blend curve.
3. Cn → Continuity at the ends of the blend.
   • 0 → Position
   • 1 → Tangency
   • 2 → Curvature
   • 3 → G3
   • 4 → G4
4. B1 → Bulge factor at the start of the blend.
5. B2 → Bulge factor at the end of the blend.

Output parameters:

1. Bc → Blend curve connecting both guide curves.