pakt23

See /software/p5js/pakt-februari/pakt23/ for a JavaScript version and /software/supercollider/februari-pakt/pakt23/ for accompanying sound code.

use nannou::lyon;
use nannou::prelude::*;

const N: usize = 250;

fn main() {
  nannou::sketch(view).size(640, 480).run();
}

fn view(app: &App, frame: Frame) {
  let draw = app.draw();
  let win = app.window_rect();

  let index = app.time * 60.0;

  let rx = (index * 0.0024).sin();
  let ry = (index * 0.0022 + 1.0).sin();
  let tx = (index * 0.0016 + 2.0).sin() + rx;
  let ty = (index * 0.0018 + 3.0).sin() + ry;

  if frame.nth() == 0 {
    frame.clear(BLACK);
  } else {
    draw.rect().wh(win.wh()).color(rgba(1.0, 1.0, 1.0, 0.02));
  }

  let mut p = lyon::math::point(0.0, 0.0);
  for i in 50..N {
    let t = i as f32 / N as f32;
    let x = t * PI * 2.0 * rx * tx;
    let y = t * PI * 2.0 * ry * ty;
    if i == 50 {
      p = lyon::math::point(x.cos() * win.w(), y.sin() * win.h()) * 0.495 * t;
    } else {
      let c = (t * PI * 2.0).sin() * 0.5 + 0.5;
      let mut builder = nannou::geom::path::Builder::new().with_svg();
      builder.move_to(p);
      p = lyon::math::point(x.sin() * win.w(), y.cos() * win.h()) * 0.495 * t;
      builder.line_to(p);
      p = lyon::math::point(x.cos() * win.w(), y.sin() * win.h()) * 0.495 * t;
      builder.line_to(p);
      builder.close();
      let path = builder.build();
      draw.scale_axes(vec3(1.0, -1.0, 1.0))
        .path()
        .stroke()
        .color(rgba(c, 0.0, 0.0, c))
        .events(path.iter());
    }
  }

  draw.to_frame(app, &frame).unwrap();
}