fletcher.paths.rounded-vertex()

Incoming leg and circular segments of a rounded corner.

Returns the line segment to point P and a single cubic Bézier segment to Q.

            ┌─── d ───┐
************P***──────@-[i-angle]
       ..   │   **   /
      .     r     * /
      .     ╵     */
      .           Q
       ..      ../
         ...... /
               /
          [o-angle]

@ = vertex
* = segments returned by this function

fletcher.paths.rounded-vertex(
  vertex,
  i-angle,
  o-angle,
  radius,
)