Ok, lets me discuss my ideas of algorithm for the Finding Tangent Support Points:
We generally have these cases:
1) Start is a point end is a point (arcseg -> arcseg, concave arc -> concave arc)
2) Start is a pont end is a convex arc. (arcseg -> convex arc, concave arc -> convex arc)
- Is is easy to compute tangent from point to circle (outward tangent because there are two)
- Next, we have tangent point on circle, togo have `contains` method to check the point is on the arc.
If it is not the point is on one of the arc's ends.
Similar in reverse, when the start is convex arc and the end is arc.
3) Start is on convex arc end is on convex arc (convex arc -> convex arc)
- Compute outward tangent to two circles
- Check end end is on the arcs using the `contains` method. If some/both ends are not on arcs,
use arcs endpoints and check from all combinations what support points create most outward line.