let centerY;

let radius;

let dotRadiusMin = 0.1;

let dotRadiusMax = 50;

let powerBase = 1.01;

let done;

let x;

let chunkSize = 10;

​

function setup()

{

  createCanvas(400, 400);

  Clear();

  Begin();

}

​

function keyPressed()

{

  switch (keyCode)

  {

    case 32: // Spacebar

      Begin();

      break;

    case BACKSPACE:

      Clear();

      break;

  }

}

​

function draw()

{

  if (done === true)

    return;

  for (let target = x + chunkSize; x < target; ++x)

  {

    for (let y = 0; y < height; ++y)

      DrawPoint(x, y);

    if (x >= width)

    {

      done = true;

      break;

    }

  }

}

​

function Clear()

{

  blendMode(BLEND);

  background(40);

  blendMode(ADD);

}

​

function Begin()

{

  done = false;

  x = 0;

  centerX = 400 * Math.random();

  centerY = 400 * Math.random();

  radius = (200 - 10) * Math.random() + 10;

}

​

function DrawPoint(x, y)

{

  let distance = dist(centerX, centerY, x, y);

  let delta = abs(distance - radius);

  let alpha = pow(powerBase, -8 * delta);

  alpha /= 4;

  stroke(alpha * 250, alpha * 180, alpha * 50);

  strokeWeight((dotRadiusMax - dotRadiusMin) * pow(Math.random(), 200) + dotRadiusMin);

  point(x, y);

}

​