Create tangent circles or arcs between a point and a curve.

Input parameters:

1. As → Start point for tangent arcs.
2. At → Start direction of tangent arcs.
3. Ct → Constraining curve for tangent arcs.
4. Mt → Tangent arc output method.
   • 0 → Any
   • 1 → Along
   • 2 → Against
   • 3 → Clear
   • 4 → Circle
   • 5 → Shortest
   • 6 → Longest

Output parameters:

1. Ar → Arcs from the given point to the constraint curve.
2. Lc → Constraint curve loci at arc end points.
3. Xd → Tangent angle error at the constraint curve.