【週刊p5js】work01

function setup() {
  createCanvas(windowWidth, windowHeight);
  pixelDensity(2);
  frameRate(1);
  // noLoop(); // mousePressed用
}

let ColorPattern = [
  ['#493548','#FFC145','#FF6B6C','#5B5F97','#4B4E6D'],
  ['#FFC145','#FF6B6C','#5B5F97','#4B4E6D','#493548'],
  ['#FF6B6C','#5B5F97','#4B4E6D','#493548','#FFC145'],
  ['#5B5F97','#4B4E6D','#493548','#FFC145','#FF6B6C'],
  ['#4B4E6D','#493548','#FFC145','#FF6B6C','#5B5F97']
];

let g = 7;

function grid(){
  let   w = width / g;
  let   h = height / g;

  // グリッド線
  for (let i = 1; i <= g - 1; i++) {
    stroke(150);
    strokeWeight(1);
    line(w * i, 0, w * i, height);
    line(0, h * i, width, h * i);
  }

  // ランダムで白塗り
  for (let i = 0; i < g; i++) {
    let col = int(random(g));
    let row = int(random(g));
    fill(200);
    rect(col * w, row * h, w, h);
  }
}

function grain() {
  for (let i = 0; i < 100000; i++) {
    fill(255, 30);
    circle(random(width), random(height), 2);
  }
}
 
function draw() {
  resizeCanvas(windowWidth, windowHeight);

  let l = ColorPattern.length;
  let p = int(random(l));

  colorP = ColorPattern[p];

  let ll = colorP.length;

  bgColor = colorP[0];
  background(bgColor);

  grid();

  for (let i = 0; i < 85; i++) {
    if (i < 15 || i % 2 == 0){
      continue;
    }

    let Cd = colorP[int(random(ll))];
    while (Cd == bgColor) {
      Cd = colorP[int(random(ll))];
    }
    r = i * 2;

    noStroke();
    
    // 外側の円
    fill(Cd);
    x = random(width);
    y = random(height);
    ellipse(x, y, r);

    // 内側の円2
    fill(bgColor);
    x_diff = x + random(-5,5);
    y_diff = y + random(-5,5);
    ellipse(x_diff, y_diff, r*0.6);
  }

  for(let i = 0; i < 20000; i++) {
    ellipse(random(width), random(height), random(0.75));
  }
}

function mousePressed() {
  redraw();
}