day_17.js

// (c) 2021 Joseph HENRY
// This code is licensed under MIT license (see LICENSE for details)

let yellow, orange, pink;

let offset = 0;

function lines(x, y, size, nLines, offset, fromColor, toColor) {
  const slice = TWO_PI / nLines;
  const radius = size / 2;
  
  push();
  translate(x, y);
  
  for (let i = 0; i < nLines; i++) {
    randomSeed(i * 500);
    
    const angle = i * slice;
    const rotMultiplier = sin(angle / 2) + 1;
    const rotation = angle * rotMultiplier + offset;
    const color = lerpColor(fromColor, toColor, random(1));
    
    stroke(color);
    strokeWeight(map(sin(rotation * 2), -1, 1, size / 20, size / 5));
    
    push();
    translate(cos(angle) * radius, sin(angle) * radius);
    rotate(rotation);
    line(0, 0, size / 4, 0);
    pop();
  }
  
  pop();
}

function setup() {
  createCanvas(500, 500);
  
  yellow = color("#ff9900");
  orange = color("#ff5500");
  pink = color("#ff7c67");
}

function draw() {
  background("#003344");
  
  translate(width / 2, height / 2);
  
  noStroke();
  fill(pink);
  circle(0, 0, 120 + sin(offset) * 20);
  
  fill(orange);
  circle(0, 0, 100 + sin(offset + QUARTER_PI) * 10);
  
  fill(yellow);
  circle(0, 0, 50 + sin(offset) * 20);
  
  
  lines(0, 0, 250, 50, offset, yellow, orange);
  lines(0, 0, 150, 25, offset, orange, pink);
  
  offset += 0.03;
}