pakt08

See /software/p5js/pakt-februari/pakt08/ for a JavaScript version and /software/supercollider/februari-pakt/pakt08/ for accompanying sound code.

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

const N: u16 = 25;

fn main() {
  nannou::app(model)
    .update(update)
    .simple_window(view)
    .size(640, 480)
    .run();
}
struct Model {
  d: f32,
  theta: f32,
  speed: f32,
  spread: f32,
  points: Vec<Point2>,
}
fn model(_app: &App) -> Model {
  let d = 0.0001;
  let theta = 0.0;
  let speed = 0.00002;
  let spread = 2.0;
  let mut points = vec![];
  for _i in 0..N {
    points.push(pt2(0.0001, 0.0001));
  }
  Model {
    d,
    theta,
    speed,
    spread,
    points,
  }
}
fn update(app: &App, model: &mut Model, _update: Update) {
  let win = app.window_rect();
  for (i, p) in model.points.iter_mut().enumerate() {
    let i = i as f32;
    let c = (model.theta + (i * model.d)).cos();
    let s = (model.theta + (i * model.d)).sin();
    let x = p.x / win.w();
    let y = p.y / win.h();
    p.x = ((c * x) - (s * y)) * win.w() + model.spread;
    p.y = ((c * y) + (s * x)) * win.h() + model.spread;
    model.theta += model.speed;
  }
}
fn view(app: &App, model: &Model, frame: Frame) {
  let draw = app.draw();
  frame.clear(BLACK);
  let mut builder = nannou::geom::path::Builder::new().with_svg();
  for p in model.points.iter() {
    builder.line_to(lyon::math::point(p.x, p.y));
  }
  builder.close();
  let path = builder.build();
  draw.scale_axes(vec3(1.0, -1.0, 1.0))
    .color_blend(BLEND_SUBTRACT)
    .path()
    .fill()
    .color(RED)
    .events(path.iter());

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