Further reading
In the TikZ manual at https://texdoc.org/pkg/tikz, our topics are covered in Part III in the following sections:
- Section 14.3, The Curve-To Operation is about the curve syntax using control points. It’s online at https://tikz.dev/tikz-paths#sec-14.3.
- Section 22, Plots of Functions describes TikZ’s basic plotting syntax, including the
smoothoption. You can read it online at https://tikz.dev/tikz-plots.
https://en.wikipedia.org/wiki/B%C3%A9zier_curve in Wikipedia is a good starting point for reading about Bézier curves and finding further documents.
http://weitz.de/hobby is a JavaScript demonstration of the Hobby algorithm versus cubic splines, where you can define and move points by simple mouse clicks in a drawing.
The hobby library is explained at https://texdoc.org/pkg/hobby. For even more background, you can read the MetaPost manual at https://texdoc.org/pkg/metapost, particularly Section 4.2, Specifying Direction, Tension...
