I have begun experimenting with Inkscape’s “spiro” mode for curves. Since I usually end up writing Python to create art that Inkscape just doesn’t have the tools to accomplish, I’m curious what the math behind the “spiro” curves is.
What formulas does Inkscape use to choose the Bézier handle points for Spiro paths?
The core curve of the spiro path is the Euler spiral. Although the implementation’s math may be flawless, I personally believe the input method may be suboptimal: The handles are ignored.