Pixl.js Multiplayer Pong Game

Based on this Pong Game for Pixl.js, this code uses the buttons instead of potentiometers, and adds wireless multiplayer using two Pixl.js boards. See the video above for full details.

This uses the Bluetooth LE UART module to handle communications.

Get connected to Espruino with the Web IDE, copy and paste the following code into the right-hand side of the IDE, and click the upload button!

Source Code

var BATSIZE = 8;
// Scores of players
var scorel = 0;
var scorer = 0;
// Bat and ball positions
var batl = 0;
var batr = 0;
var ball;
// Peripheral=the slave, Central=game host
var isPeripheral;
var isConnected;
// Bluetooth LE UART
var uart;

function newGame() {
  ball = {
    x : g.getWidth()/2,
    y : g.getHeight()/2,
    vx : ((Math.random()>0.5)?1:-1)*2,
    vy : (Math.random()-0.5)*4
  };
}

function status(text) {
  g.clear();
  g.setFontAlign(0,0);
  g.drawString(text,64,32);
  g.setFontAlign(-1,-1);
  g.flip();
}

function connect(device) {
  isPeripheral = false;
  isConnected = false;
  status("Connecting...");
  require("ble_uart").connect(device).then(function(u) {
    status("Connected!");
    isConnected = true;
    uart = u;
    uart.on('data', function(d) {
      uartd = d;
      batr = parseInt(d);
    });
    gameStart();
  }).catch(function(e) {
    print(e.toString());
    setTimeout(doScan, 4000);
  });
}

function waitConnect() {
  Pixl.menu();
  isPeripheral = true;
  Terminal.setConsole(1); // move the JS console out the way
  Bluetooth.on('data', function(d) {
    d = d.split(",");
    if (d.length==3) {
      ball.x = parseInt(d[0]);
      ball.y = parseInt(d[1]);
      batr = parseInt(d[2]);
    }
  });
  status("Waiting... ("+NRF.getAddress().substr(-5)+")");
}

function doScan() {
  Pixl.menu();
  status("Scanning...");
  NRF.findDevices(function (devices) {
    devices = devices.filter(x => x.name && x.name.substr(0,4)=="Pixl");
    var options = {
      "": {"title":"Select a device"},
      "Wait for connection": waitConnect,
      "Toggle Backlight": function() {
        LED.toggle();
      }
    };
    devices.forEach(function(dev) {
      options[dev.name] = function() {
        Pixl.menu();
        connect(dev);
      };
    });
    options["Rescan..."] = doScan;
    Pixl.menu(options);
  });
}

function onFrame() {
  if (BTN2.read()) resetGame();
  if (BTN1.read()) batl-=2;
  if (BTN4.read()) batl+=2;
  if (batl<BATSIZE) batl=BATSIZE;
  if (batl>g.getHeight()-BATSIZE) batl=g.getHeight()-BATSIZE;

  if (!isPeripheral) {
    ball.x += ball.vx;
    ball.y += ball.vy;
    if (ball.y<=0) ball.vy = Math.abs(ball.vy);
    if (ball.y>=g.getHeight()-1) ball.vy = -Math.abs(ball.vy);
    if (ball.x<5 &&
        ball.y>batl-BATSIZE && ball.y<batl+BATSIZE) {
      ball.vx = Math.abs(ball.vx);
    }
    if (ball.x>g.getWidth()-6  &&
        ball.y>batr-BATSIZE && ball.y<batr+BATSIZE) {
      ball.vx = -Math.abs(ball.vx);
    }
    if (ball.x<0) {
      scorer++;
      newGame();
    }
    if (ball.x>g.getWidth()-1) {
      scorel++;
      newGame();
    }
    uart.write(Math.round(128-ball.x)+","+Math.round(ball.y)+","+Math.round(batl));
  } else {
    if (isConnected) Bluetooth.print(batl);
  }

  g.clear();
  g.fillRect(0,batl-BATSIZE, 3,batl+BATSIZE);
  g.fillRect(g.getWidth()-4,batr-BATSIZE, g.getWidth()-1,batr+BATSIZE);
  g.fillRect(ball.x-1,ball.y-1,ball.x+1,ball.y+1);
  g.setFontAlign(-1,-1);
  g.drawString(scorel, 10,0);
  g.setFontAlign(1,-1);
  g.drawString(scorer, g.getWidth()-10,0);
  g.flip();
}

function gameStart() {
  scorel = 0;
  scorer = 0;
  newGame();
  setInterval(onFrame, 200);
}

function resetGame() {
  isConnected = false;
  if (uart) {
    uart.disconnect();
    uart = undefined;
  }
  status("Game Over");
  clearInterval(); // remove all intervals
  Bluetooth.removeAllListeners();
  if (isPeripheral) Terminal.setConsole(); // don't 'force' the console away any more
  doScan();
}

NRF.on('connect', function() {
  isConnected = true;
  gameStart();
});
NRF.on('disconnect', function() {
  isConnected = false;
  resetGame(); // when disconnected, leave the game
});

function onInit() {
  // at boot, re-enter scan mode
  doScan();
}

onInit();