manifold

let points = [];
let sigma, rho, beta;
function setup() {
  cnv = createCanvas((w = min(windowWidth, windowHeight) * 0.9), w);
  for (let i = 0; i < 5000; i++) {
    points[i] = {
      x: randomGaussian(0, w / 6),
      y: randomGaussian(0, w / 6),
      z: randomGaussian(0, w / 6)
    };
  }
  sigma = random(5, 15);
  rho = random(15, 40);
  beta = random(8 / 3, 20 / 3);
  noStroke();
}

function draw() {
  translate(w / 2, w / 2);
  t = frameCount / 100;
  rotate(t / 5);
  for (let i = 0; i < points.length; i++) {
    let dt = random(0.00001, 0.0002);
    let dx = sigma * (points[i].y - points[i].x) * dt;
    let dy = (points[i].x * (rho - points[i].z) - points[i].y) * dt;
    let dz = (points[i].x * points[i].y - beta * points[i].z) * dt;
    points[i].x += dx;
    points[i].y += dy;
    points[i].z += dz;
    push();
    x = points[i].x * sin(t / 2) + points[i].z * cos(t / 2);
    y = points[i].y * sin(t / 2) + points[i].x * cos(t / 2);
    fill(
      50 + 50 * sin(points[i].x / 90 - t),
      150 + 100 * sin(points[i].y / 90 - t),
      200 + 100 * sin(points[i].z / 90 + t / 2),
      10
    );
    circle(x, y, 5);
    fill(255, 255, 255, 120);
    circle(x, y, 1);
    pop();
  }
  for (let i = 0; i < 20; i++) {
    points.shift();
    points.push({
      x: randomGaussian(0, w / 5),
      y: randomGaussian(0, w / 5),
      z: randomGaussian(0, w / 5)
    });
  }
  push();
  rotate(-t / 5);
  noFill();
  stroke(255);
  rect(-w / 2 + w / 20, -w / 2 + w / 20, w - w / 10, w - w / 10);
  pop();
}

function keyPressed() {
  if (keyCode === 83) {
    save(cnv, "manifold", "png");
  }
  if (keyCode === 32) {
    setup();
    draw();
  }
  console.log(points.length);
}

function windowResized() {
  resizeCanvas((w = min(windowWidth, windowHeight) * 0.9), w);
}