flappybird.js

/** Simple Flappy Bird Game */

var SPEED = 0.5;
var BIRDIMG = {
  width : 8, height : 8, bpp : 1,
  transparent : 0,
  buffer : new Uint8Array([
    0b00000000,
    0b01111000,
    0b10000100,
    0b10111010,
    0b10100100,
    0b10000100,
    0b01111000,
    0b00000000,
  ]).buffer
};


var birdy, birdvy;
var wasPressed = false;
var running = false;
var barriers;
var score;

function newBarrier(x) {
  barriers.push({
    x1 : x-5,
    x2 : x+5,
    y : 10+Math.random()*(g.getHeight()-20),
    gap : 8
  });
}

function gameStart() {
  running = true;
  birdy = g.getHeight()/2;
  birdvy = 0;
  barriers = [];
  newBarrier(g.getWidth()/2);
  newBarrier(g.getWidth());
  score = 0;
  wasPressed = false;
  setInterval(onFrame, 50);    
}

function gameStop() {
  running = false;
  clearInterval();  
  setTimeout(function() {
    setWatch(gameStart, BTNA, {repeat:0,debounce:50,edge:"rising"});
  }, 1000);
  setTimeout(onFrame, 10);
}

function onFrame() {
  var buttonState = BTN.read();
  
  g.clear();
  if (!running) {
    g.drawString("Game Over!",25,10);
    g.drawString("Score",10,20);
    g.drawString(score,10,26);
    g.flip();
    return;
  }  
  
  if (buttonState && !wasPressed)
    birdvy -= 2;
  wasPressed = buttonState;
  
  score++;
  birdvy += 0.2;
  birdvy *= 0.8;
  birdy += birdvy;
  if (birdy > g.getHeight())
    return gameStop();
  // draw bird
  g.drawImage(BIRDIMG, 0,birdy-4);
  // draw barriers
  barriers.forEach(function(b) {
    b.x1-=SPEED;
    b.x2-=SPEED;
    var btop = b.y-b.gap;
    var bbot = b.y+b.gap;
    g.drawRect(b.x1+1, -1, b.x2-2, btop-5);
    g.drawRect(b.x1, btop-5, b.x2, btop);
    g.drawRect(b.x1, bbot, b.x2, bbot+5);
    g.drawRect(b.x1+1, bbot+5, b.x2-1, g.getHeight());
    if (b.x1<6 && (birdy-3<btop || birdy+3>bbot))
      return gameStop();
  });
  while (barriers.length && barriers[0].x2<=0) {
    barriers.shift();
    newBarrier(g.getWidth());
  }

  g.flip();
}

function onInit() {
  gameStart();
}

onInit();