let tops;

let size = 200;

let startSand = 20000;

let clickAmountSlider;

let speedSlider;

​

function setup () {

​

    createP('Drop amount');

    clickAmountSlider = createSlider(100, 100000, 10000);

​

    createP('Speed');

    speedSlider = createSlider(1, 1000, 10);

​

    createCanvas(size, size);

    //frameRate(1);

    pixelDensity(1);

    initPiles();

​

}

​

function initPiles () {

​

    sandpiles = new Array (width);

    for (let x = 0; x < sandpiles.length; x++) {

        sandpiles[x] = new Array(height);

        for (let y = 0; y < sandpiles[x].length; y++) {

            sandpiles[x][y] = 0;

        }

    }

​

    let x = Math.floor(width/2);

    let y = Math.floor(height/2);

    sandpiles[x][y] = startSand;

    tops = new Array();

    tops.push(x + y*width);

​

}

​

function addIfNotExists(arr,  value) {

    if (!arr.includes(value)) {

        arr.push(value);

    }

}

​

function topple() {

​

    if (mouseclicks.length > 0) {

        for (var i = 0; i < mouseclicks.length; i++) {

            let index = mouseclicks[i];

            let y = Math.floor(index/width);

            let x = index % width;

            sandpiles[x][y] = clickAmountSlider.value();

            tops.push(index);

        }

        mouseclicks =  [];

    }

​

    tempTops = tops;

    tops = new Array();

​

    for (var i = 0; i < tempTops.length; i++) {

​

        index = tempTops[i];

        let y = Math.floor(index/width);

        let x = index % width;

​

        sandpiles[x][y] -= 4;

        if (sandpiles[x][y] > 3) {

            addIfNotExists(tops, x + y * width);

        } else {

            let where = tops.indexOf(x + y * width);

            if (where !== -1) {

              tops.splice(where, 1);

            }

        }

​

        if (x-1 >= 0) {

            sandpiles[x-1][y]++;

            if (sandpiles[x-1][y] == 4) {

                addIfNotExists(tops, x-1 + y * width);

            }

        }

​

        if (x+1 < width) {

            sandpiles[x+1][y]++;

            if (sandpiles[x+1][y] == 4) {

                addIfNotExists(tops, x+1 + y * width);

            }

        }

​

        if (y-1 >= 0) {

            sandpiles[x][y-1]++;

            if (sandpiles[x][y-1] == 4) {

                addIfNotExists(tops, x + (y-1) * width);

            }

        }

​

        if (y+1 < height) {

            sandpiles[x][y+1]++;

            if (sandpiles[x][y+1] == 4) {

                addIfNotExists(tops, x + (y+1) * width);

            }

        }

​

    } //for loop

​

}

​

let mouseclicks = [];

function mouseClicked() {

    mouseclicks.push(mouseY*width + mouseX);

}

​

function getColor (num) {

    switch (num) {

        case 0: return color(6, 65, 255);

        case 1: return color(127, 189, 255);

        case 2: return color(255, 222, 1);

        case 3: return color(103, 9, 2);

        default: return color(103, 9, 2);

    }

}

​

function setPixelColor (index, col) {

    pixels[index+0] = red(col);

    pixels[index+1] = green(col);

    pixels[index+2] = blue(col);

    pixels[index+3] = 255;

}

​

function draw() {

​

  loadPixels();

  for (let y = 0; y < height; y++) {

    for (let x = 0; x < width; x++) {

      let index = (x + y * width)*4;

            let col = getColor(sandpiles[x][y]);

            setPixelColor(index, col);

    }

  }

  updatePixels();

    for (var i = 0; i < speedSlider.value(); i++) {

        topple();

    }

​

​

}

​