['','',''],

  ['','',''],

  ['','',''],

];

​

// let player1 = 'X';//players

// let player2 = 'O';

​

let players = ['X','O'];

​

let currentPlayer;

let available = [];

​

// function setup() {

//   createCanvas(400, 400);

//   if (random(1) < 0.5) {

//     currentPlayer = players[0];

//   } else {

//     currentPlayer = players[1];

//   }

// }

function setup() {

  createCanvas(400, 400);

  frameRate(30);

  currentPlayer = floor(random(players.length));

  for(let j=0;j<3;j++) {

    for (let i = 0;i<3;i++) {

      available.push([i,j]);

    }

  }

}

​

​

function equals3(a,b,c) {

  return (a==b && b==c && a !='');

}

​

function checkWinner() {

  let winner = null;

  //horizontal

  for(let i=0; i<3; i++) {

    if(equals3(board[i][0], board[i][1],board[i][2])) {

      winner = board[i][0];

    }

  }

  //vertical

  for(let i=0;i<3;i++) {

    if(equals3(board[0][i], board[1][i], board[2][i])) {

      winner = board[0][i];

    }

  }

  //diagonal

  if(equals3(board[0][0], board[1][1], board[2][2])) {

    winner = board[0][0];

  }

  if(equals3(board[2][0], board[1][1], board[0][2])) {

    winner = board[2][0];

  }

  if(winner == null && available.length == 0) {

    return 'tie';

  } else {

    return winner;

  }

}

​

function nextTurn() {

  let index = floor(random(available.length));

  let spot = available.splice(index,1)[0];

  let i = spot[0];

  let j = spot[1];

  board[i][j] = players[currentPlayer];

  currentPlayer = (currentPlayer + 1) % players.length;

}

​

// function mousePressed() {

//   nextTurn();

// }

​

function draw() {

  background(255);

  let w = width / 3;

  let h = height / 3;

   strokeWeight(4);

  //nested loop to check every column

  line(w, 0, w, height);

  line(w * 2, 0, w * 2, height);

  line(0, h, width, h);

  line(0, h * 2, width, h * 2);

  for (let j = 0; j<3; j++) {

    for (let i =0 ; i<3;i++) {

      let x = w * i + w / 2;

      let y = h * j + h / 2;

      let spot = board[i][j];

      textSize(32);

      if( spot == players[1]) {

        noFill();

        ellipse(x, y, w / 2);

      } else if (spot == players[0]){

        let xr = w / 4;

        line( x - xr , y - xr, x + xr, y + xr);

        line( x + xr , y - xr, x - xr, y + xr);

      }

  }

  }

  let result = checkWinner();

  if (result !=null) {

    noLoop(); 

    let resultP = createP('');

  resultP.style('font-size','32pt');

    if(result == 'tie') {

      resultP.html("Tie!")

    } else {

      resultP.html(`${result} wins!`);

    }

    } else { 

  nextTurn();

}

}