* I started translating

 * https://github.com/kimasendorf/ASDFPixelSort/blob/master/ASDFPixelSort.pde

 * to p5.js but I didn't finish :(

 */

​

let img;

let colorPixels = [];

​

function preload() {

  img = loadImage('sufjan.jpg'); 

}

​

function setup() {

  print(img.width);

  print(img.height);

  img.resize(img.width/2, img.height/2);

  createCanvas(img.width, img.height);

  noLoop();

}

​

function colorToInt(c) {

  return parseInt(c.toString('#rrggbb').substr(1), 16);

}

​

function copyPixelsToColors() {

  for (let i = 0; i < img.pixels.length; i += 4) {

    let r = img.pixels[i];

    let g = img.pixels[i+1];

    let b = img.pixels[i+2];

    let a = img.pixels[i+3];

    colorPixels.push(color(r,g,b,a)); 

  }

}

​

function copyColorsToPixels() {

  for (let i = 0; i < colorPixels.length; i+=1) {

    img.pixels[4*i] = red(colorPixels[i]);

    img.pixels[4*i+1] = green(colorPixels[i]);

    img.pixels[4*i+2] = blue(colorPixels[i]);

    img.pixels[4*i+3] = alpha(colorPixels[i]);

  }

}

​

function sortColorAsInt(a,b) {

    let ac = colorToInt(a);

    let bc = colorToInt(b);

    if (a < b) return -1;

    if (a > b) return 1;

    if (a === b) return 0;

}

​

function draw() {

  background(220);

  img.loadPixels();

  copyPixelsToColors();

  for (let y = 0; y < img.height; y +=1) {

    sortRow(y);

  }

  copyColorsToPixels();

  img.updatePixels();

  image(img, 0, 0);

}

​

function sortRow(y) {

  // print('row: ' + y);

  // black threshold

  // play around with this number!!

  let blackThreshold = 5999999;

  let brightnessThreshold = 60;

  let sortStart = -1;

  let sortEnd = -1;

  while (sortEnd < img.width-1) {

    sortStart = -1;

    let x = sortEnd + 1;

    for (; x < img.width; x +=1) {

      let c = colorPixels[x + y*width];

      // let brightnessValue = brightness(c);

      let colorAsInt = colorToInt(c);

      //print(colorAsInt);

      // let b = brightness(c);

      if (sortStart < 0) {

        // if (brightnessValue < brightnessThreshold) {

        if (colorAsInt > blackThreshold) {

          // print('sortStart: ' + colorAsInt);

          sortStart = x;

        }

      }

      if (sortStart > -1) {

        if (colorAsInt < blackThreshold || x === img.width - 1) {

          // print('sortEnd: ' + colorAsInt);

          sortEnd = x;

          break;

        }

      }

    }

    print(sortStart);

    print(sortEnd);

    if (sortStart < 0) break;

    let sortArray = colorPixels.slice(sortStart + y*width, sortEnd + y*width);

    // print('sorting row: ' + y);

    sortArray.sort(sortColorAsInt);

    for (let i = 0; i < sortArray.length; i += 1) {

      colorPixels[sortStart + y*width + i] = sortArray[i]; 

    }

  }

  // sort entire row

  // let sortStart = y*img.width;

  // let sortEnd = (y+1)*img.width - 1;

  // let sortArray = colorPixels.slice(sortStart, sortEnd);

  // sortArray.sort(sortColorAsInt);

  // for (let i = 0; i < sortArray.length; i += 1) {

  //   colorPixels[sortStart + i] = sortArray[i]; 

  // }

}