These patterns result from the intersection of two sinusoidal curves, such as made by a harmonograph pendulum. The resulting "Lissajous patterns" are particularly interesting at ratios of 1/3, 1/2, 1, 2, 3, so we pause at those ratios. You'll see a parabola at 1/3, a circle at ratio of 1, with ellipses near ratio = 1. I use a second Lissajous drawing pen that echoes the first pen but which shows a slightly different angle.
Code redraws line after each gradual increase of the ratio of two variables for the x and y coordinates. I use a sine function to slow down near intervals of 1/3, 1/2, 1, 2, 3. Has a dreamy, or nightmarish effect, much like the opening of the 1958 movie Vertigo, which used a harmonograph pendulum. Bernard Hermann composed the music for the 1958 Vertigo title sequence, which inspired me to pursue this. Here I use a midi version of the title sequence music by Hermann. This is my 3rd variant of Lissajous patterns in Scratch in the last few days. I've been a bit obsessed. See also remixes by @papipupepappa who has helped me think about this film opening and what might be happening.
