let theCircle, circles;

​

function setup() {

  gfxs = [];

  angleMode(RADIANS);

  createCanvas(800,800);  

  pixelDensity(1);

  let step = TWO_PI/64;

  background(0);

  // gfx.translate(width/2,height/2);

    let gfx = createGraphics(width, height);

    for (let i = 0; i < 10; i++) {

    gfx.fill(color(255,0,255))

    gfx.noStroke();

    gfx.fill(color(random(255), random(255), random(255), random(255)));

    gfx.circle(random(width), random(height), random(1000));

    makeDithered(gfx,1);  

    }

  gfx.filter(GRAY);

  // makeDithered(gfx,1);  

  // image(gfx,0,0);

  for (let i = 0; i < gfxs.length; i++) {

    image(gfxs[i],0,0);

  }

  noLoop();

  console.log("done");

}

​

// function draw() {

//   noLoop();

//   // background(255);

//   // translate(width/2,height/2);

// }

​

function imageIndex(img, x, y) {

  return 4 * (x + y * img.width);

}

​

function getColorAtindex(img, x, y) {

  let idx = imageIndex(img, x, y);

  let pix = img.pixels;

  let red = pix[idx];

  let green = pix[idx + 1];

  let blue = pix[idx + 2];

  let alpha = pix[idx + 3];

  return color(red, green, blue, alpha);

}

​

function setColorAtIndex(img, x, y, clr) {

  let idx = imageIndex(img, x, y);

​

  let pix = img.pixels;

  pix[idx] = red(clr);

  pix[idx + 1] = green(clr);

  pix[idx + 2] = blue(clr);

  pix[idx + 3] = alpha(clr);

}

​

// Finds the closest step for a given value

// The step 0 is always included, so the number of steps

// is actually steps + 1

function closestStep(max, steps, value) {

  return round(steps * value / 255) * floor(255 / steps);

}

​

function makeDithered(img, steps) {

  img.loadPixels();

​

  for (let y = 0; y < img.height; y++) {

    for (let x = 0; x < img.width; x++) {

      let clr = getColorAtindex(img, x, y);

      let oldR = red(clr);

      let oldG = green(clr);

      let oldB = blue(clr);

      let newR = closestStep(255, steps, oldR);

      let newG = closestStep(255, steps, oldG);

      let newB = closestStep(255, steps, oldB);

​

      let newClr = color(newR, newG, newB);

      setColorAtIndex(img, x, y, newClr);

​

      let errR = oldR - newR;

      let errG = oldG - newG;

      let errB = oldB - newB;

​

      distributeError(img, x, y, errR, errG, errB);

    }

  }

​

  img.updatePixels();

}

​

function distributeError(img, x, y, errR, errG, errB) {

  addError(img, 7 / 16.0, x + 1, y, errR, errG, errB);

  addError(img, 3 / 16.0, x - 1, y + 1, errR, errG, errB);

  addError(img, 5 / 16.0, x, y + 1, errR, errG, errB);

  addError(img, 1 / 16.0, x + 1, y + 1, errR, errG, errB);

}

​

function addError(img, factor, x, y, errR, errG, errB) {

  if (x < 0 || x >= img.width || y < 0 || y >= img.height) return;

  let clr = getColorAtindex(img, x, y);

  let r = red(clr);

  let g = green(clr);

  let b = blue(clr);

  clr.setRed(r + errR * factor);

  clr.setGreen(g + errG * factor);

  clr.setBlue(b + errB * factor);

​

  setColorAtIndex(img, x, y, clr);

}