​

function arrayEquals(a, b) {

  return (

    Array.isArray(a) &&

    Array.isArray(b) &&

    a.length === b.length &&

    a.every((val, index) => val === b[index])

  );

}

​

function expandToNeighbours(queue, current) {

  x = current.x;

  y = current.y;

​

  if (x - 1 > 0) {

    queue.push(createVector(x - 1, y));

  }

​

  if (x + 1 < width) {

    queue.push(createVector(x + 1, y));

  }

​

  if (y - 1 > 0) {

    queue.push(createVector(x, y - 1));

  }

​

  if (y + 1 < height) {

    queue.push(createVector(x, y + 1));

  }

​

  return queue;

}

​

function floodSearch(img, seed, predicate) {

  let needle;

  img.loadPixels();

​

  index = 4 * (width * seed.y + seed.x);

  seedColor = [

    img.pixels[index],

    img.pixels[index + 1],

    img.pixels[index + 2],

    img.pixels[index + 3],

  ];

​

  let queue = [];

  queue.push(seed);

  let visited = new Set();

​

  while (queue.length) {

    let current = queue.shift();

    index = 4 * (width * current.y + current.x);

    let color = [

      img.pixels[index],

      img.pixels[index + 1],

      img.pixels[index + 2],

      img.pixels[index + 3],

    ];

​

    if (

      !arrayEquals(color, seedColor) ||

      visited.has(`${current.x},${current.y}`)

    ) {

      // not inside the area we want to fill

      continue;

    }

    visited.add(`${current.x},${current.y}`);

​

    const testResult = predicate(current.x, current.y);

    if (predicate(current.x, current.y)) {

      return testResult;

    }

​

    queue = expandToNeighbours(queue, current);

  }

}

​