x2,

  scrollSpeed = 4; //values for scrolling background

let startTime,

  countdown,

  timeLimit = 60; //countdown timer

let atkCharge = 0,

  score = 0; //initial values for attack charge and score

var bestScore = 0; //high score

let gameState = "start"; //current game state

let serial;

let protagImg, copImg, copCarImg, vinylImg, cassetteImg, startScreenImg;

let gameBG; //background image

let bgm;

let powerUpSound;

let gameFont;

let cops = [],

  collectibles = [],

  projectiles = []; //arrays to store enemies, power-up collectibles and projectile attacks

let protag;

let enemySpawnTimer = 0,

  collectibleSpawnTimer = 0; //timer for spawning enemies and power-ups

let START = 0,

  ATTACK = 0,

  JUMP = 0; //input flags for actions from arduino

​

function preload() {

  //load images and music

  gameBG = loadImage("bg.png");

  protagImg = loadImage("protag.png");

  copImg = loadImage("cop.png");

  copCarImg = loadImage("copcar.png");

  vinylImg = loadImage("vinyl.png");

  cassetteImg = loadImage("cassette.png");

  startScreenImg = loadImage("startscreen.jpg");

  bgm = loadSound("fire-ex.mp3");

  gameFont = loadFont("Slackey-Regular.ttf");

}

​

function setup() {

  createCanvas(600, 400);

  x1 = 0; //intial position of first background segment

  x2 = width; //initial position of second background segment

  protag = new Protag(); //create protagonist object

  let savedBestScore = localStorage.getItem("bestScore"); //retrieve best saved score from previous games

  if (savedBestScore !== null) {

    //set best score

    bestScore = int(savedBestScore);

  }

}

​

function draw() {

  //display respective screens depending on game state

  if (gameState === "start") {

    drawStartScreen();

  } else if (gameState === "instruction") {

    drawInstructionScreen();

  } else if (gameState === "playing") {

    runGame();

  } else if (gameState === "end") {

    drawEndScreen();

  }

  //play background music

  bgm.playMode("untilDone");

  bgm.play();

}

​

function runGame() {

  // set up countdown timer

  let currentTime = millis();

  let elapsedTime = (currentTime - startTime) / 1000;

  countdown = timeLimit - floor(elapsedTime);

  if (countdown < 0) {

    gameState = "end";

  }

​

  // load background

  image(gameBG, x1, 0, width, height);

  image(gameBG, x2, 0, width, height);

  fill("rgb(71,97,113)");

  rect(0, height - height / 3.2, width, height / 3.2);

​

  // background scrolling

  x1 -= scrollSpeed;

  x2 -= scrollSpeed;

  if (x1 < -width) x1 = x2 + width;

  if (x2 < -width) x2 = x1 + width;

​

  // display protagonist

  protag.display();

  protag.move();

​

  spawnEntities(); //spawn enemies and power-ups

​

  // handle collisions between objects

  handleCollisions();

​

  // handle attacks

  handleAttacks();

​

  // draw attack charge bar and timer

  drawHUD();

}

​

function drawStartScreen() {

  image(startScreenImg, 0, 0, width, height);

​

  if (START === 1) {

    gameState = "instruction";

    START = 0; // reset START to prevent immediate state transition

  }

}

​

function drawInstructionScreen() {

  //display game instructions

  background("rgb(255,131,40)");

  fill(255);

  textFont(gameFont);

  textSize(16);

  textAlign(CENTER, CENTER);

  text("INSTRUCTIONS", width / 2, 50);

  textSize(14);

  text(

    "You wake up as a Taiwanese guitarist in the 1990s \n" +

      " and you're running late to a gig!\n" +

      "1. Use the controls to jump and attack.\n" +

      "2. Avoid contact with Cops and Cop Cars.\n" +

      "3. Collect Vinyl and Cassettes to charge attacks.\n" +

      "4. Press ATTACK to fire projectiles.\n" +

    "5. Cars take 2 attacks to destroy. Cops take just 1.\n" +

      "6. Score points by blasting enemies out of your way.\n" +

      "Your band awaits!",

    width / 2,

    height / 2

  );

  textSize(20);

  text("Press START to begin the game", width / 2, height - 50);

​

  if (START === 1) {

    startTime = millis();

    gameState = "playing"; //begin main game

    START = 0;

  }

}

​

function drawEndScreen() {

  background("rgb(253,144,98)");

  fill(255);

  textAlign(CENTER);

  textSize(35);

  textSize(20);

  text("Your Score: " + score, width / 2, height / 2);

  text("High Score: " + bestScore, width / 2, height / 2.5);

  text("Press START to return to the start screen", width / 2, height / 2 + 60);

​

  if (START === 1) {

    restartGame();

    gameState = "start"; // return to start screen

    START = 0;

  }

​

}

​

function restartGame() {

  //reset variables for new game

  score = 0;

  startTime = millis();

  countdown = timeLimit;

  gameState = "start";

}

​

function spawnEntities() {

  //check if enough time (2 seconds) has passed to spawn an enemy so that they don't overlap

  if (millis() - enemySpawnTimer > 2000) {

    //spawn either cop or cop car

    if (random() > 0.5) {

      cops.push(new Cop());

    } else {

      cops.push(new CopCar());

    }

    //update spawn timer to current time

    enemySpawnTimer = millis();

  }

  if (millis() - collectibleSpawnTimer > 3000) {

    if (random() > 0.5) {

      collectibles.push(new Vinyl());

    } else {

      collectibles.push(new Cassette());

    }

    collectibleSpawnTimer = millis();

  }

}

​

function handleCollisions() {

  // handle collisions with cops and cop cars

  for (let i = cops.length - 1; i >= 0; i--) {

    cops[i].display();

    cops[i].move();

​

    if (protag.hits(cops[i])) {

      // decrease score on contact

      score = max(0, score - 1); // prevent negative score

​

      if (cops[i] instanceof CopCar) {

        cops[i].hitsRemaining--;

        if (cops[i].hitsRemaining <= 0) {

          cops.splice(i, 1); // remove CopCar if hit enough times

        }

      } else {

        cops.splice(i, 1); // remove Cop

      }

    }

  }

​

  // handle collisions with power-up collectibles

  for (let i = collectibles.length - 1; i >= 0; i--) {

    collectibles[i].display();

    collectibles[i].move();

​

    if (protag.hits(collectibles[i])) {

      if (collectibles[i] instanceof Cassette) {

        atkCharge = min(3, atkCharge + 1); // cap attack charge at 3

      } else if (collectibles[i] instanceof Vinyl) {

        atkCharge = min(3, atkCharge + 2);

      }

      collectibles.splice(i, 1); // remove collectible after contact

    }

  }

}

​

function handleAttacks() {

  if (ATTACK === 1 && atkCharge > 0) {

    projectiles.push(new Projectile(protag.x + 20, protag.y + 10));

    atkCharge -= 1; // decrease attack charge when an attack is used

    ATTACK = 0;

  }

​

  // move and display projectiles

  for (let i = projectiles.length - 1; i >= 0; i--) {

    projectiles[i].move();

    projectiles[i].display();

​

    // check for collisions with enemies

    for (let j = cops.length - 1; j >= 0; j--) {

      if (projectiles[i].hits(cops[j])) {

        if (cops[j] instanceof CopCar) {

          cops[j].hitsRemaining--;

          if (cops[j].hitsRemaining <= 0) {

            score += 2; // increase score for defeating cop car

            cops.splice(j, 1);

          }

        } else {

          score += 1; // increase score for defeating cop

          cops.splice(j, 1);

        }

        projectiles.splice(i, 1); // remove projectile upon hit

        break; // break out of loop since the projectile is gone

      }

    }

  }

}

​

function readSerial(data) {

  //read input from arduino

  if (data != null) {

    let fromArduino = split(trim(data), ",");

    if (fromArduino.length == 3) {

      JUMP = int(fromArduino[0]);

      ATTACK = int(fromArduino[1]);

      START = int(fromArduino[2]);

    }

  }

}

​

function windowResized() {

  print("resized to " + windowWidth + "," + windowHeight);

  resizeCanvas(windowWidth, windowHeight);

}

​

function keyPressed() {

  //press space bar to establish serial connection

  if (key === " ") {

    setUpSerial();

  }

}

​

function keyTyped() {

  if (key === "f") {

    toggleFullscreen();

  }

}

​

function toggleFullscreen() {

  let fs = fullscreen(); // Get the current state

  fullscreen(!fs); // Flip it!

}

​

function drawHUD() {

  // timer display

  fill(0);

  textSize(16);

  textFont(gameFont);

  textAlign(RIGHT, TOP);

  text("Time: " + countdown, width - 20, 10);

​

  // attack charge bar display

  let barX = width - 110;

  let barY = 40;

  let barWidth = 100;

  let barHeight = 20;

  let barFillWidth = (atkCharge / 3) * barWidth; // width based on atkCharge (max 3)

​

  // bar background

  noStroke();

  fill(200);

  rect(barX, barY, barWidth, barHeight);

  fill('red');

  rect(barX, barY, barFillWidth, barHeight);

​

  // score display

  fill(0);

  textAlign(LEFT, TOP);

  textSize(20);

  text("Score: " + score, 20, 10);

}

​