app.js

kEmptyIterationMillis = 4
kPutSpriteMillis = 40
kMainLoopMillis = 150
kRocketsLoopMillis = 150
kStatusBeamLoopMillis = 220


var SC=0, SH
var P, C
var H, G
var selectedCharacterImage = 0
var ratioX, ratioY;

function selectCharacter(character) {
  selectedCharacterImage = character;
  document.getElementById("selectCharacterDialog").style.display = "none";
  document.getElementById("character-selected-img").src = "img/characters/"+selectedCharacterImage+".png";
    document.getElementById("characterSelected").style.display = "block";
}

function changeRocket() {
  var rocket = document.getElementById("sprite0")
  document.getElementById("sprite3").src = 'img/rockets/r_jeff.png'
  if (selectedCharacterImage == 'elon') {
    rocket.src = 'img/rockets/elon.png'
  } else if (selectedCharacterImage == 'jeff') {
    rocket.src = 'img/rockets/jeff.png'
    document.getElementById("sprite3").src = 'img/rockets/r_elon.png'
  } else {
    rocket.src = 'img/rockets/rocket.png'
  }
}

function blastar() {
  document.getElementById('game').style.display = 'block';

  resizeHandler();

  canvas = document.getElementById("canvas");
  ctx = canvas.getContext("2d");
  ctx.font = "24px Commodore, Courier New";
  ctx.strokeStyle = "#BBBBBB";
  ctx.lineWidth = 3;
  ctx.fillRect(0, 0, 750 * ratioX, 600 * ratioY);

  fillTextStyle = "#BBBBBB"
  SH=5;SC=0
  screen(2)
  printTxt(Array(14).join(" ") + "BLASTAR")
  startGame()
}

function startGame() {
  cls()
  // Load Sprites
  sprite = [document.getElementById("sprite0"),
            null,
            document.getElementById("sprite2"),
            document.getElementById("sprite3"),
            document.getElementById("sprite4"),
            document.getElementById("sprite5"),
            document.getElementById("sprite6")]
  spriteBits = [
    [0x99, 0x99, 0x99, 0xe7, 0xc3, 0xc3, 0xc3, 0xc3],  // Ship
    [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00],
    [0x00, 0x00, 0x42, 0xa5, 0x42, 0x00, 0x00, 0x00],  // Rockets
    [0x18, 0x42, 0xe7, 0xbd, 0x5a, 0x24, 0x3c, 0x66],  // Freighter
    [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00],  // Explosion
    [0x00, 0x10, 0x38, 0x7c, 0x7c, 0x38, 0x10, 0x00]   // Status Beam
  ]
  changeRocket()
  mainProgram()
  moveFirstHalf()
}

function mainProgram() {
  cls()
  locate(0,0);
  printTxt("   SCORE" + SC + "       SHIPS " + SH)
  P = 120; C = 180
  H = 30; G = 15
  spriteOn()
  startLoop(mainLoop, kMainLoopMillis)
}

function mainLoop() {
  maybeMoveShip()
  putSprite(3, H, G)
  if (Math.abs(H-P) <= 1) {
    stopLoop()
    fireStatusBeam()
  } else {
    H+=3
    if (H>250) H = 10
    if (F) {
      stopLoop()
      shootRockets()
    }
  }
}

function maybeMoveShip() {
  F = strig()
  D = stick()
  putSprite(3, H, G)
  switch (D) {
    case 1: C-=4; break
    case 2: P+=2;C-=2; break
    case 3: P+=4; break
    case 4: P+=2;C+=2; break
    case 5: C+=4; break
    case 6: P-=2;C+=2; break
    case 7: P-=4; break
    case 8: P-=2;C-=2; break
  }
  putSprite(0, P, C)
  if (C<10) C=10
  if (C>190) C=180
  if (P<10) P=10
  if (P>240) P=240
}

function shootRockets() {
  U=P;W=C-5
  playSoundAndEnterRocketsLoop()
}

function playSoundAndEnterRocketsLoop() {
  play(4, 6, 50, "D", playRocketSound2)
}
function playRocketSound2() {
  play(4, 6, 30, "F", enterRocketsLoop)
}

function enterRocketsLoop() {
  startLoop(rocketsLoop, kRocketsLoopMillis)
}

function rocketsLoop() {
  putSprite(3, H, G)
  H += 4
  W -= 6
  putSprite(2, U, W)
  if (H == P) {
    stopLoop()
    fireStatusBeam()
  } else {
    maybeMoveShip()
    spriteOn()
    onSpriteGoSub(destroyFreighter)
    if (F) {
      stopLoop()
      shootRockets()
    } else if (W < -10) {
      stopLoop()
      startLoop(mainLoop, kMainLoopMillis)
    }
  }
}

function destroyFreighter() {
  SC += 80
  putSprite(4, H, G)
  setTimeout(newFreighter, 20*kPutSpriteMillis)
}

function newFreighter() {
  cls()
  locate(0, 0)  // (sic)
  printTxt("SCORE" + SC + "            SHIPS " + SH)
  spriteOff()
  G = 20 + Math.floor(Math.random() * 150)
  startLoop(mainLoop, kMainLoopMillis)
}

function fireStatusBeam() {
  OO=H;NN=G+5
  startLoop(statusBeamLoop, kStatusBeamLoopMillis)
}

function statusBeamLoop() {
  spriteOn()
  NN += 4
  PI=P;maybeMoveShip();P=PI
  locate(15, 15); printTxt("            STATUS BEAM")
  onSpriteGoSub(destroyShip)
  putSprite(5, OO, NN)
  play(2, 9, 15, "B", maybeEndStatusBeamLoop)
}
function maybeEndStatusBeamLoop() {
  if (NN > 205) {
    // goto 620
    stopLoop()
    startLoop(mainLoop, kMainLoopMillis)
  }
}

function destroyShip() {
  SH -= 1
  setTimeout(nextShip, 60*kEmptyIterationMillis)
}

function nextShip() {
  cls()
  locate(0, 0)
  printTxt("SCORE " + SC + "             SHIPS " + SH)
  putSprite(5, 128, 205)
  putSprite(6, P, C)
  G = 20 + Math.floor(170 * Math.random())
  H = 0
  spriteOff()
  if (SH >= 0) {
    stopLoop();
    startLoop(mainLoop, kMainLoopMillis)
  } else {
    cls()
    locate(0, 0)
    printTxt("                BLASTAR"); printTxt("")
    printTxt("             FLEET DESTROYED"); printTxt("")
    printTxt("      WOULD YOU LIKE ANOTHER GAME")
    inKey(maybeStartAnotherGame)
  }
}

function maybeStartAnotherGame(key) {
  if (key == 121 || key == 89) {
    blastar()
  } else {
    // TODO: how do I end?
    printTxt(">")
  }
}

/////////////////////////////////////////////////////////////////////////////////////
var currentInterval

function startLoop(loop, period) {
  function f() {
    try {
      loop()
    } catch(e) {}
  }
  currentInterval = setInterval(f, period)
}

function stopLoop() {
  clearInterval(currentInterval)
}

//////////////////////// just-enough BASIC emulation code ///////////////////////////

var lastKeyDownMillis = 0
var left = false
var right = false
var up = false
var down = false
var spacebar = false

var ctx
var fillTextStyle
var cursorRow = 0, cursorCol = 0
var textBuffers = []
var keyPressCallback = null

// TODO: clean up sprite vars.
var sprite = []
var spriteX = [-10,-10,-10,-10,-10,-10,-10,-10]
var spriteY = [-10,-10,-10,-10,-10,-10,-10,-10]
var spriteBits
var spriteStatus = false
var onSprite = null


function initBasicEnvironment() {
  for (var i = 0; i < 25; i++) textBuffers.push("");
  initSound();
  initEventHandling();
  inKey(function() {});
}

function putSprite(id, x, y) {
  spriteX[id] = x
  spriteY[id] = y
  redraw()
  if (spriteStatus) checkCollisions()
}

function redraw() {
  ctx.fillStyle = "#000000"
  ctx.fillRect(0, 0, 750 * ratioX, 600 * ratioY)
  ctx.fillStyle = fillTextStyle

  for (var i = 0; i < textBuffers.length; i++) {
    ctx.fillText(textBuffers[i], 0, (i + 2)*24 * ratioY, 750 * ratioY)
  }

  for (var i = 0; i < sprite.length; i++) {
    if (sprite[i]) ctx.drawImage(sprite[i], spriteX[i]*3 * ratioX, spriteY[i]*3 * ratioY, 24 * ratioY, 60 * ratioY)
  }
}

function checkCollisions() {
  if (!onSprite) return
  for (var i = 0; i < 4; i++) {
    if (spriteX[i] < 0 || spriteY[i] > 204) continue
    xi = spriteX[i]; yi = spriteY[i]
    for (var j = i + 1; j < 6; j++) {
      if (spriteX[j] < 0 || spriteY[j] > 204) continue
      if (i == 0 && j == 2) continue  // Friendly fire
      xj = spriteX[j]; yj = spriteY[j]
      if (Math.abs(xi - xj) < 8 && Math.abs(yi - yj) < 8) {
        for (var y = Math.max(yi, yj); y < Math.min(yi + 8, yj + 8); y++) {
          if (xj < xi) {
            if ((spriteBits[i][y - yi] << (xi-xj)) & spriteBits[j][y - yj]) collision()
          } else {
            if ((spriteBits[j][y - yj] << (xj-xi)) & spriteBits[i][y - yi]) collision()
          }
        }
      }
    }
  }
}

function collision() {
  stopLoop()
  tmpOnSprite = onSprite
  onSprite = null
  tmpOnSprite()
  throw "Interrupt"
}

function spriteOn() {
  spriteStatus = true
  checkCollisions()

  // Added
  spriteX[2] = -10
  spriteX[4] = -10
  spriteX[5] = -10
  spriteX[6] = -10
}

function spriteOff() {
  onSprite = null
  spriteStatus = false

  // Added
  spriteX = [-10,-10,-10,-10,-10,-10,-10,-10]
}

function onSpriteGoSub(sub) {
  onSprite = sub
  if (spriteStatus) checkCollisions()
}

function locate(row, col) {
  cursorRow = row
  cursorCol = col
}

function printTxt(txt) {
  oldText = textBuffers[cursorRow]
  pre = oldText.substr(0, cursorCol)
  pre += Array(cursorCol - pre.length + 1).join(" ")
  textBuffers[cursorRow] = pre + txt + oldText.substr(cursorCol + pre.length + txt.length)
  cursorRow++
  cursorCol = 0
  redraw()
}

function cls() {
  ctx.fillStyle = "#000000"
  ctx.fillRect(0, 0, 750 * ratioX, 600 * ratioY)
  for (var i = 0; i < textBuffers.length; i++) textBuffers[i] = ""
  spriteX = [-10,-10,-10,-10,-10,-10,-10,-10]
  locate(0, 0)
}

function screen(a, b) {
  cls()
}

function initEventHandling() {
  window.addEventListener("keypress", keyPress, false)
  // Prevents double-tap to zoom, runs at most one of (mouse, touch) events.
  function neuter(e) {
    e.stopPropagation();
    e.preventDefault();
  }
  function pressSpaceBar(e) {
    fakeKeyDown(32)
    fakeKeyUp(32)
    neuter(e)
  }
  //spcbar = document.getElementById("spcbar")
  //spcbar.addEventListener("mousedown", pressSpaceBar, false)
  //spcbar.addEventListener("touchstart", pressSpaceBar, false)

  function addKeyEvents(el, keyCode) {
    function genKeyDown(evt) {
      fakeKeyDown(keyCode);neuter(evt)
    }
    el.addEventListener("mousedown", genKeyDown, false)
    el.addEventListener("touchstart", genKeyDown, false)
    function genKeyUp(evt) {
      fakeKeyUp(keyCode);neuter(evt)
    }
    el.addEventListener("mouseup", genKeyUp, false)
    el.addEventListener("touchend", genKeyUp, false)
  }
  addKeyEvents(document.getElementById("left"), 37)
  addKeyEvents(document.getElementById("up"), 38)
  addKeyEvents(document.getElementById("right"), 39)
  addKeyEvents(document.getElementById("down"), 40)
  addKeyEvents(document.getElementById("spcbar"), 32)

  // Prevent double tap zoom on gamepad.
  var gamepad = document.getElementById("gamepad")
  gamepad.addEventListener("mousedown", neuter)
  gamepad.addEventListener("touchstart", neuter)
  gamepad.addEventListener("mouseup", neuter)
  gamepad.addEventListener("touchend", neuter)
}

function keyDown(evt) {
  lastKeyDownMillis = Date.now()
  switch (evt.keyCode) {
    case 37: left = true; break
    case 39: right = true; break
    case 40: down = true; break
    case 38: up = true; break
    case 32: spacebar = true; break
    default: return
  }
  evt.preventDefault()
}

var konamiCode = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65]
var konamiCodeIndex = 0

function keyUp(evt) {
  if (konamiCodeIndex < konamiCode.length) {
    if (evt.keyCode != konamiCode[konamiCodeIndex++]) {
      if (konamiCodeIndex == 3 && evt.keyCode == 38) {
        konamiCodeIndex = 2
      } else {
        konamiCodeIndex = 0
      }
    }
    if (konamiCodeIndex == konamiCode.length) {
      sprite[0] = document.getElementById("dragon")
    }
  }
  switch (evt.keyCode) {
    case 37: delayRelease(function() {left = false}); break
    case 39: delayRelease(function() {right = false}); break
    case 40: delayRelease(function() {down = false}); break
    case 38: delayRelease(function() {up = false}); break
    case 32: delayRelease(function() {spacebar = false}); break
    default: return
  }
  evt.preventDefault()
}

function delayRelease(callback) {
  setTimeout(callback, Math.max(0, kMainLoopMillis - (Date.now() - lastKeyDownMillis)))
}

function fakeKeyDown(keyCode) {
  if (keyPressCallback == null) keyDown({keyCode: keyCode, preventDefault: function(){}})
}

function fakeKeyUp(keyCode) {
  evt = {keyCode: keyCode, preventDefault: function(){}}
  if (keyPressCallback == null) {
    keyUp(evt)
  } else {
    keyPress(evt)
  }
}

function strig() {
  return spacebar
}

function stick() {
  r = right && !left
  l = left && !right
  u = up && !down
  d = down && !up
  if (r) {
    if (u) {
      return 2
    } else if (d) {
      return 4
    }
    return 3
  } else if (l) {
    if (u) {
      return 8
    } else if (d) {
      return 6
    }
    return 7
  } else if (u) {
    return 1
  } else if (d) {
    return 5
  }
  return 0
}

function inKey(callback) {
  keyPressCallback = callback
  window.removeEventListener("keydown", keyDown, false)
  window.removeEventListener("keyup", keyUp, false)
  up = down = right = left = spacebar = false
}

function keyPress(evt) {
  if (keyPressCallback) {
    tmpKeyPressCallback = keyPressCallback
    keyPressCallback = null
    window.addEventListener("keydown", keyDown, false)
    window.addEventListener("keyup", keyUp, false)
    tmpKeyPressCallback(evt.keyCode || evt.which)
    evt.preventDefault()
  }
}


// SOUND SYNTHESIS

var samplingRate = 22050
var semiTones = {}
var speaker = []
var currentSpeaker = 0

function initSound() {
  semiTones["C"] = 0
  semiTones["C#"] = 1
  semiTones["D"] = 2
  semiTones["E-"] = 3
  semiTones["E"] = 4
  semiTones["F"] = 5
  semiTones["F#"] = 6
  semiTones["G"] = 7
  semiTones["G#"] = 8
  semiTones["A"] = 9
  semiTones["B-"] = 10
  semiTones["B"] = 11
  speaker[0] = document.getElementById("speaker0");
  speaker[1] = document.getElementById("speaker1");
  var mutedCheckbox = document.getElementById("muted");
  mutedCheckbox.checked = window.localStorage.getItem("muted");
  toggleMute(mutedCheckbox)
}

function toggleMute(muted) {
  window.localStorage.setItem('muted', muted.checked);
  speaker[0].muted = muted.checked
  speaker[1].muted = muted.checked
}

function encodeLong(value) {
  enc = "";
  for (var i = 0; i < 4; ++i) {
    enc += String.fromCharCode(value % 256);
    value = Math.floor(value / 256);
  }
  return enc
}

function wavHeader(n) {
  return ("RIFF" + encodeLong(36 + 2*n) + "WAVEfmt \x10\x00\x00\x00\x01\x00\x01\x00" +
          encodeLong(samplingRate) + encodeLong(2*samplingRate) + "\x02\x00\x10\x00data" +
          encodeLong(2*n))
}

function encodeWave(wave) {
  var n = wave.length;
  var raw = wavHeader(n)
  for (var i = 0; i < n; ++i) {
    var sample = Math.round(wave[i] * 32767);
    if (sample < 0) sample += 1<<16;
    raw += String.fromCharCode(sample % 256);
    raw += String.fromCharCode(Math.floor(sample / 256));
  }
  return "data:audio/wav;base64," + btoa(raw);
}

function addSoundWave(frequency, duration, amplitude, wave) {
  amplitude *= 0.25
  // Pulse wave, width=half period. A=0, D=0, S=amplitude, R=0.
  numSamples = Math.round(duration * samplingRate)
  periodSamples = Math.round(samplingRate * 1.0 / frequency)
  for (var i = 0, ii=0; i < numSamples; ++i, ++ii) {
    if (ii >= periodSamples) ii -= periodSamples
    if (ii < periodSamples / 2) {
      wave.push(amplitude)
    } else {
      wave.push(-amplitude)
    }
  }
  return wave
}

function addNote(o, v, l, note, wave) {
  cFreq = 32.7 * Math.pow(2, o)
  frequency = cFreq * Math.pow(Math.pow(2.0, 1/12), semiTones[note])
  addSoundWave(frequency, (2.0/l)*7/8, v/15, wave)
  return addSoundWave(frequency, (2.0/l)*1/8, 0, wave)
}

function playInSpeaker(wave) {
  if (!document.getElementById("muted").checked) {
    new Audio(encodeWave(wave)).play();
  }
  // speaker[currentSpeaker].src = encodeWave(wave)
  // speaker[currentSpeaker].play()
  // currentSpeaker = 1 - currentSpeaker
}

function play(o, v, l, notes, callback) {
  wave = []
  for (var i = 0; i < notes.length; ++i) {
    addNote(o, v, l, notes[i], wave)
  }
  playInSpeaker(wave)
  window.setTimeout(callback, 1000 * wave.length / samplingRate)
}

function beep() {
  wave = []
  addSoundWave(800, 0.25, 9/15, wave)
  playInSpeaker(wave)
}


var hasAlreadyMoved = false;
var kSecondsAfterTweet = 40;
var kFuelPercentangeForTweet = 0;
var kIntervalInMilisecondsLosing1Percent = (kSecondsAfterTweet / (100 - kFuelPercentangeForTweet)) * 1000;

function moveFirstHalf() {
  if (hasAlreadyMoved == false) {
    hasAlreadyMoved = true;
    var elem = document.getElementById("fuel-green");
    var widthPercentage = 100;
    var initialWidth = elem.getBoundingClientRect().width;
    var id = setInterval(frame, kIntervalInMilisecondsLosing1Percent);
    function frame() {
      if (widthPercentage <= kFuelPercentangeForTweet) {
        clearInterval(id);
        showTweet();
        return;
      }
      widthPercentage--;
      elem.style.width = initialWidth * (widthPercentage / 100) + "px";
    }
  }
}


var hasAlreadyMovedAfterCTA = false;
var kSecondsAfterCTA = 30;
var kFuelPercentangeForCTA = 0;
var kIntervalInMilisecondsLosing1PercentForCTA =
  (kSecondsAfterCTA / (100 - kFuelPercentangeForCTA)) *
  1000;

function moveSecondHalf() {
  document.getElementById('tweetScreen').style.display = 'none';
  if (hasAlreadyMovedAfterCTA == false) {
    hasAlreadyMovedAfterCTA = true;
    var elem = document.getElementById("fuel-red");
    var widthPercentage = 100;
    var initialWidth = elem.getBoundingClientRect().width;
    var id = setInterval(frame, kIntervalInMilisecondsLosing1PercentForCTA);
    function frame() {
      if (widthPercentage <= kFuelPercentangeForCTA) {
        clearInterval(id);
        displayRedirectCTA();
        stopLoop();
        return;
      }
      widthPercentage--;
      elem.style.width = initialWidth * (widthPercentage / 100) + "px";
    }
  }
}

function showTweet() {
  document.getElementById('tweetScreen').style.display = 'flex';
}


function displayCaptcha() {
  document.getElementById('characterSelected').style.display = 'none';
  document.getElementById('captcha').style.display = 'block';
}

const music = new Audio("alert_alarm.mp3");

function displayRedirectCTA() {
  document.getElementById('redirect_cta').style.display = 'block';
  document.getElementById('game').style.display = 'none';

  music.loop = true;
  if (!document.getElementById("muted").checked) {
    music.play();
  }
}

$(function() {
  $(".not-a-robot input").on('click', function() {
    document.getElementById('captcha').style.display = 'none';
    blastar();
  });

  $(".captcha-image").on("click", function () {
    $(this).toggleClass("checked");
  });

  $(".tweet-dialog").on('click', function() {
    moveSecondHalf();
  })
});

function resizeHandler() {
  var elem = document.getElementById("canvas-container");
  var bbox = elem.getBoundingClientRect();

  ratioX = bbox.width / 750;
  ratioY = bbox.height / 600;

  var canvas = document.getElementById("canvas");
  canvas.width = bbox.width;
  canvas.height = bbox.height;
}

$(function () {
  initBasicEnvironment();
  resizeHandler();
  window.addEventListener('resize', resizeHandler);
})

function stopMusic() {
  music.pause();
}

function restart() {
  window.location.reload(); 
}

function onHyperlinkClickPreventAppOpen(ev) {
  const el = ev.target;
  if(el.href) {
    ev.preventDefault();
    window.document.location.assign(el.href);
  }
}

function clickUltrahumanLink(ev) {
  stopMusic();
  onHyperlinkClickPreventAppOpen(ev);
}