Wavemaker

Adapted from https://p5js.org/examples/interaction-wavemaker.html

This illustrates how waves (like water waves) emerge from particles oscillating in place. Move your mouse to direct the wave. Contributed by Aatish Bhatia, inspired by Orbiters by Dave Whyte.

from proceso import Sketch


p5 = Sketch()
p5.describe(
    "A grid of green spirals on a black background. The spirals change their motion based on the mouse position."
)


def setup():
    p5.create_canvas(600, 600)
    p5.no_stroke()
    p5.fill(40, 200, 40)


def draw():
    p5.background(10, 10)  # translucent background (creates trails)

    # make a x and y grid of ellipses
    for x in range(0, p5.width, 30):
        for y in range(0, p5.height, 30):
            # starting point of each circle depends on mouse position
            x_angle = p5.remap(p5.mouse_x, 0, p5.width, -4 * p5.PI, 4 * p5.PI, True)
            y_angle = p5.remap(p5.mouse_x, 0, p5.height, -4 * p5.PI, 4 * p5.PI, True)
            # and also varies based on the particle's location
            angle = x_angle * (x / p5.width) + y_angle * (y / p5.height)

            # each particle moves in a circle
            t = p5.frame_count * 0.01
            my_x = x + 20 * p5.cos(2 * p5.PI * t + angle)
            my_y = y + 20 * p5.sin(2 * p5.PI * t + angle)

            p5.circle(my_x, my_y, 10)  # draw particle


p5.run_sketch(setup=setup, draw=draw)

View sketch