Pick a curve from a list.

Input parameters:

1. Cs → List of curves to pick from.
2. Pt → Picking point.
3. Mt → Picking method.
   • 0 → Nearest
   • 1 → Start Point
   • 2 → End Point
   • 3 → Nearest End
   • 4 → Midpoint

Output parameters:

1. Cr → Picked curve.
2. Ix → Index of picked curve.