- Click on a circle, then release the mouse button to remove the circle.
- Click on the curve, move the mouse, then release the button to change the shape.
- I also made a version for closed loops.

Here is the theory behind some modifications.

- nodes (the circles) can be added or removed
*a correction of the calculation:*

The original calculation contained an error in the last node.

When it was applied to a spline of only 2 nodes, the result would be a curve, not a straight line

*an adaptation for small segments:*

originally, curves would look like this, if nodes were near each other:

I decided that for smaller segments, the control points of the Bézier curve should be near the nodes.

This adaptation required a bit of calculus, because the curvature (say, the 2nd derivative of the spline with respect to "length of path") had to remain continuous at a node. (Whether this is visible or not - I programmed it in that way).

The result is