// author: Winston Smith, @sequentialchaos

// created: Aug. 5, 2020

// https://editor.p5js.org/sequentialchaos/sketches/OxlrTVclo

​

const NUM_TRIANGLES = 30;

let n = 2.192;

let d = 42.984;

let i = 0.959;

let j = 1.328;

let p, r;

let h1, h2, hrange, hinc;

​

function setup() {

  createCanvas(innerWidth, innerHeight);

  colorMode(HSB, 1, 1, 1, 1);

  noStroke();

​

  p = PI

  r = (width + height) / 2 * 0.75;

  hrange = 0.10

  h1 = 0

  h2 = h1 + hrange

  hinc = 0.00001

}

​

function draw() {

  translate(width / 2, height / 2);

  background(0, 0.05);

  for (let w = 0; w < NUM_TRIANGLES; w++) {

    let t = i + w;

    let p1 = maurer(t, n, d, r);

    let p2 = maurer(t + p, n, d, r);

    let p3 = maurer(t + p + 0.01, n, d, r);

    h1 = (h1 + hinc) % (1-hrange)

    h2 = (h1 + hrange) % 1

    h = map(w / NUM_TRIANGLES, 0, 1, h1, (h1 + h2))

    fill(h, 1, 1, 0.01);

    triangle(p1.x, p1.y, p2.x, p2.y, p3.x, p3.y);

  }

  i += PI / 100000;

  j += PI / 50000;

  p = map(easeInOutQuad((j % PI) / PI), 0, 1, PI, PI * 3);

  d += 0.0001;

  n += 0.00001;

  // showValues()

}

​

function maurer(t, n, d, rMax) {

  let k = t * d;

  let r = rMax * sin(n * k);

  let x = r * cos(k);

  let y = r * sin(k);

  return { x, y };

}

​

function showValues() {

  push()

  resetMatrix()

  fill(1)

  stroke(0)

  textSize(40)

  text(`n = ${n.toFixed(3)}`, 20, 50)

  text(`d = ${d.toFixed(3)}`, 20, 100)

  text(`i = ${i.toFixed(3)}`, 20, 150)

  text(`j = ${j.toFixed(3)}`, 20, 200)

  text(`p = ${p.toFixed(3)}`, 20, 250)

  pop()

}

​

function easeInOutQuad(t) {

  return t < 0.5 ? 2 * t * t : -1 + (4 - 2 * t) * t;

}

​