pakt00

See /software/p5js/pakt-februari/pakt00/ for a JavaScript version and /software/supercollider/februari-pakt/pakt00/ for accompanying sound code.

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

const N: u16 = 120;

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

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

  let rad = win.h();
  for angle in 0..360 {
    let angle = angle as f32;
    let mut points = Vec::with_capacity(3);
    points.push((pt2(0.0, 0.0), rgb(1.0, 1.0, 0.8)));

    let vx = angle.to_radians().cos();
    let vy = angle.to_radians().sin();
    points.push((pt2(vx, vy) * rad, rgb(0.0, 0.0, 0.0)));

    let next_vx = (angle + 1.0).to_radians().cos();
    let next_vy = (angle + 1.0).to_radians().sin();
    points.push((pt2(next_vx, next_vy) * rad, rgb(0.0, 0.0, 0.0)));

    draw.polygon().points_colored(points);
  }

  let index = app.time * 60.0;
  let mut builder = nannou::geom::path::Builder::new().with_svg();
  for i in 0..N {
    let i = i as f32;
    let start = ((index + i) * 0.006 + i).sin() * PI;
    let end = ((index + i) * 0.0123 + i).sin() * PI * 2.0;

    if start < end {
      let r = (index * 0.01 + i).sin() * 70.0 + 75.0;
      let x = start.sin() * r;
      let y = start.cos() * r;
      builder.move_to(lyon::math::point(x, y));
      builder.arc(
        lyon::math::point(0.0, 0.0),
        lyon::math::vector(r, r),
        lyon::math::Angle::radians(start - end),
        lyon::math::Angle::radians(0.0),
      );
    } else {
      let r = (index * 0.01 + i).sin() * 50.0 + 55.0;
      let ox = (i * 0.21).sin() * win.w() * 0.25;
      let oy = (i * 0.2).cos() * win.h() * 0.25;
      let x = start.sin() * r;
      let y = start.cos() * r;
      builder.line_to(lyon::math::point(x + ox, y + oy));
      builder.arc(
        lyon::math::point(ox, oy),
        lyon::math::vector(r, r),
        lyon::math::Angle::radians(end - start),
        lyon::math::Angle::radians(0.0),
      );
    }
    builder.move_to(lyon::math::point(0.0, 0.0));
  }
  builder.close();
  let path = builder.build();
  draw.scale_axes(vec3(1.0, -1.0, 1.0))
    .path()
    .stroke()
    .color(rgb(1.0, 1.0, 0.8))
    .events(path.iter());

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