let cols, rows; // Number of columns and rows in the grid

let cellSize = 20; // Size of each cell

let flowDirection = 0; // Variable to control the flow direction

​

function setup() {

  createCanvas(600, 600);

  cols = width / cellSize; // Calculate the number of columns

  rows = height / cellSize; // Calculate the number of rows

  grid = [];

​

  // Initialize the grid with Cell objects

  for (let i = 0; i < cols; i++) {

    grid[i] = [];

    for (let j = 0; j < rows; j++) {

      grid[i][j] = new Cell(i * cellSize, j * cellSize, cellSize); // Create a new cell for each position

    }

  }

}

​

function draw() {

  background(0); // Set a dark background

​

  // Draw each cell in the grid

  for (let i = 0; i < cols; i++) {

    for (let j = 0; j < rows; j++) {

      grid[i][j].update(); // Update the cell (change its color or motion)

      grid[i][j].display(); // Display the cell

    }

  }

}

​

function mousePressed() {

  // Change the flow direction when the mouse is pressed

  flowDirection = (flowDirection + 1) % 2;

}

​