​

let islands = [];

let sandPile = [];

let img;

let startX = 50,

  startY = 10;

​

function preload() {

  img = loadImage("assets/train.png");

}

​

function setup() {

  createCanvas(500, 300);

​

  let v = [];

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

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

      let h = img.get(x, y);

      if (h[0] != 0)

        v.push(

          new Sand({

            x: startX + x,

            y: startY + y,

            w,

            h,

          })

        );

    }

​

  islands = groupConnectedByColorAndCoordinates(v, 0.0006, w);

}

​

function addIsland(startX, startY, sizeX, sizeY, h) {

  let island = [];

  for (let i = -sizeX; i < sizeX; i++) {

    for (let j = -sizeY; j < sizeY; j++) {

      island.push(new Sand({ x: startX + i * w, y: startY + j * w, w, h }));

    }

  }

  islands.push(island);

}

​

function draw() {

  background(0);

  // image(img, startX, startY);

​

  for (const island of islands) {

    for (const sand of island) {

      if (sand.updateStatus(sandPile)) {

        sandPile.push(sand);

      }

      sand.step();

      sand.draw();

    }

  }

​

  if (islands.length > 0)

    islands = islands

      .map((island) => island.filter((sand) => sand.status !== "stopped"))

      .filter((islands) => islands.length > 0);

​

  for (const sand of sandPile) sand.draw();

}

​

function mousePressed() {

  const islandIndex = getIslandByCoords(mouseX, mouseY);

​

  if (islandIndex === -1) return;

  for (let i = 0; i < islands[islandIndex].length; i++) {

    islands[islandIndex][i].pressed();

  }

}

​

function getIslandByCoords(x, y) {

  return islands.findIndex(

    (island) => island.findIndex((sand) => sand.isInside(x, y)) !== -1

  );

}

​

// ChatGPT Generated function below

function groupConnectedByColorAndCoordinates(objects, hueThreshold, distanceThreshold) {

    // Convert RGB to HSL to extract hue

    function rgbToHsl(rgb) {

        const r = rgb[0] / 255;

        const g = rgb[1] / 255;

        const b = rgb[2] / 255;

​

        const max = Math.max(r, g, b);

        const min = Math.min(r, g, b);

        let h, s, l = (max + min) / 2;

​

        if (max === min) {

            h = s = 0; // achromatic

        } else {

            const d = max - min;

            s = l > 0.5 ? d / (2 - max - min) : d / (max + min);

​

            switch (max) {

                case r:

                    h = ((g - b) / d + (g < b ? 6 : 0)) / 6;

                    break;

                case g:

                    h = ((b - r) / d + 2) / 6;

                    break;

                case b:

                    h = ((r - g) / d + 4) / 6;

                    break;

            }

        }

        return [h, s, l];

    }

​

    // Helper function to check if two hue values are close

    function areHuesClose(hue1, hue2) {

        return Math.abs(hue1 - hue2) <= hueThreshold;

    }

​

    // Helper function to check if two objects are close enough in coordinates

    function areObjectsClose(obj1, obj2) {

        const distance = Math.sqrt(Math.pow(obj1.x - obj2.x, 2) + Math.pow(obj1.y - obj2.y, 2));

        return distance <= distanceThreshold;

    }

​

    // Initialize visited flag for each object

    const visited = new Array(objects.length).fill(false);

​

    // Depth-first search to find connected objects

    function dfs(index, island) {

        visited[index] = true;

        island.push(objects[index]);

​

        // Check neighbors for connectivity

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

            if (!visited[i] && areHuesClose(rgbToHsl(objects[index].h)[0], rgbToHsl(objects[i].h)[0]) &&

                areObjectsClose(objects[index], objects[i])) {

                dfs(i, island);

            }

        }

    }

​

    const islands = [];

​

    // Find islands

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

        if (!visited[i]) {

            const island = [];

            dfs(i, island);

            islands.push(island);

        }

    }

​

    return islands;

}