script.js

//Global Constants
const clueHoldTime = 1000; //how long to hold each clue's light/sound
const cluePauseTime = 333; //how long to pause in between clues
const nextClueWaitTime = 1000; //how long to wait before starting playback of the clue sequence
const patternLength = 8;
//Global Variables
//var pattern = [2, 2, 4, 3, 2, 1, 2, 4];
var pattern = [];
var progress = 0;
var gamePlaying = false;
var tonePlaying = false;
var volume = 0.5; // must be between 0.0 and 1.0
var guessCounter = 0;

function randomButton(min, max){ // generates a random number from 1 - 4, representing a button
    min = Math.ceil(min);
    max = Math.floor(max);
    return Math.floor(Math.random() * (max - min + 1)) + min;
}
function generatePattern(){ // makes a random pattern every time the game is started
  for(let i = 0; i < patternLength; i++){
      pattern.push(randomButton(1,4));
  }
  return pattern;
}

function startGame(){
  //initialize game variables
  generatePattern();
  progress = 0;
  gamePlaying = true;
  //swap the Start and Stop Buttons
  document.getElementById("startBtn").classList.add("hidden");
  document.getElementById("stopBtn").classList.remove("hidden");
  playClueSequence();
}
function stopGame(){
  //Update game variables to stop the game
  gamePlaying = false;
  pattern = [];
  document.getElementById("startBtn").classList.remove("hidden");
  document.getElementById("stopBtn").classList.add("hidden");
  
}
function lightButton(btn){
  document.getElementById("button" + btn).classList.add("lit")
}
function clearButton(btn){
  document.getElementById("button" + btn).classList.remove("lit")
}
function playSingleClue(btn){
  if(gamePlaying){
    lightButton(btn);
    playTone(btn, clueHoldTime);
    setTimeout(clearButton, clueHoldTime, btn);
  }
}
function playClueSequence(){
  guessCounter = 0;
  let delay = nextClueWaitTime;
  for(let i = 0; i <= progress; i++){
    console.log("play single clue: " + pattern[i] + " in " + delay + "ms")
    setTimeout(playSingleClue, delay, pattern[i])
    delay += clueHoldTime
    delay += cluePauseTime;
  }
}
function guess(btn){
  console.log("user guessed: " + btn);
  if (!gamePlaying){
    return;
  }
  //game logic
  if(pattern[guessCounter] == btn){
    //Guess is correct
    if(guessCounter == progress){
      if(progress == pattern.length - 1){
        // Game is Won!
        winGame();
      }else{
        //Pattern correct. Add next segment
        progress++;
        playClueSequence();
      }
    }else{
      // so far so good, check the next guess
      guessCounter++;
    }
  }else{
    //Guess was incorrect and game is lost
    loseGame();
  }
}
function winGame(){
  stopGame();
  alert("Game Over. You won!");
}
function loseGame(){
  stopGame();
  alert("Game Over. You lost.");
}
// Sound Synthesis Functions
const freqMap = {
  1: 261.6,
  2: 329.6,
  3: 392,
  4: 466.2
}
function playTone(btn,len){ 
  o.frequency.value = freqMap[btn]
  g.gain.setTargetAtTime(volume,context.currentTime + 0.05,0.025)
  context.resume()
  tonePlaying = true
  setTimeout(function(){
    stopTone()
  },len)
}
function startTone(btn){
  if(!tonePlaying){
    context.resume()
    o.frequency.value = freqMap[btn]
    g.gain.setTargetAtTime(volume,context.currentTime + 0.05,0.025)
    context.resume()
    tonePlaying = true
  }
}
function stopTone(){
  g.gain.setTargetAtTime(0,context.currentTime + 0.05,0.025)
  tonePlaying = false
}

// Page Initialization
// Init Sound Synthesizer
var AudioContext = window.AudioContext || window.webkitAudioContext 
var context = new AudioContext()
var o = context.createOscillator()
var g = context.createGain()
g.connect(context.destination)
g.gain.setValueAtTime(0,context.currentTime)
o.connect(g)
o.start(0)