let texts = [

  "back and forth",

  "round and round",

  "the quick brown fox jumped over the lazy dog",

];

let _text;

let offset;

​

let circle_radius;

​

let maxR;

function drawArcs() {

  let retval = false;

​

  push();

  translate(width / 2, height / 2);

  strokeWeight(random(0.5, 2.0));

  // stroke(color(255,0,255));

  let startt = random(0, TWO_PI);

  for (

    let t = startt;

    t < startt + TWO_PI;

    t += TWO_PI / random([16, 32, 64, 128, 256])

  ) {

    stroke(color(0, random(20, 220), 0));

    point(currR * cos(t), currR * sin(t));

  }

  currR += random(1, 10);

  pop();

​

  if (currR >= maxR) retval = true;

​

  return retval;

}

​

function setup() {

  createCanvas(1000, 1000);

​

  offset = width * 0.05;

  textFont("Courier");

  textSize(48);

  textAlign(LEFT);

​

  textid = 0; //random(texts.length - 1) | 0;

  _text = texts[textid];

  // noStroke();

  fill(20);

​

  background(220);

  // text(_text, 100, 100, width / 2);

  stroke(20);

​

  maxR = width / 2;

​

  circle_radius = width / 4;

}

​

let step = 0;

let yDraw = 0;

let currR = 0;

function draw() {

  if (step == 0) {

    let xdist = map(yDraw, 0, height, 0.005, 0.5);

    for (let _ = 0; _ < width * xdist; _++) {

      let x = random(width);

      strokeWeight(random(0.1, 1.0));

​

      let bgColor = color(20);

      let circColor = lerpColor(

        color(20),

        color(255, 0, 255),

        map(yDraw, 0, height, 0.0, 1.0)

      );

​

      if (circCollision(x, yDraw, width / 2, height / 2, 1, circle_radius)) {

        stroke(circColor);

      } else {

        stroke(bgColor);

      }

      point(x, yDraw); // + random(-1, 1));

    }

    yDraw++;

    if (yDraw > height) step++;

  } else if (step == 1) {

    let done = true;//false;

    // if (textid == 0) done = drawArcs();

​

    if (done) step++;

  } else {

    //     stroke(20);

    //     strokeWeight(0.75);

    //     noFill();

​

    //     rect(offset, offset, width - 2 * offset, height - 2 * offset);

    noFill();

    stroke(0);

    circle(width/2,height/2,circle_radius*2);

    noLoop();

  }

}

​

//(x2-x1)^2 + (y2-y1)^2 <= (r1+r2)^2

function circCollision(x1, y1, x2, y2, r1, r2) {

  let l = (x2 - x1) ** 2 + (y2 - y1) ** 2;

  let r = (r1 + r2) ** 2;

​

  return l <= r;

}

​