let bullets = [];

let enemies = [];

let stars = [];

let powerups = [];

let gamestate;

let posterImage;

let fighter;

let player;

let laser;

let enemy;

let score = 0;

let title_screen_audio;

let playing_screen_audio;

let end_screen_audio;

let laser_sound_effect;

let enemySpawnRate =1;

let timeElapsed = 0;

​

​

function preload() {

  posterImage = loadImage('SpaceShooterBackground.png'); //Loading main menu

  fighter = loadImage('NicePng_spaceship-png_138961.png'); //Loading spaceship

  laser = loadImage('LaserBullet.png'); //Loading laser bullet

  enemy = loadImage('invader.png'); //Loading enemies

  font = loadFont('GameOverFont.ttf'); //Loading Game Over Screen Font

  title_screen_audio = loadSound("SkyFire (Title Screen).mp3");

  playing_screen_audio = loadSound("Battle in the Stars.mp3"); //Loading menu music

  end_screen_audio = loadSound("gameEndMusic.mp3");  //Load Game Over Screen Music

  laser_sound_effect = loadSound("lasershot.wav"); //Load laser sound effect

}

​

function setup() {

  createCanvas(400, 600);

  gamestate = 'menu'; //Setting gamestate menu

  player = new Spaceship(67, 61); //Initializing Sapceship class as the player

​

  for (let i = 0; i < 100; i++) {

    stars[i] = new Star(random(width), random(height), random(1, 5)); //Randomly generating stars

  }

}

​

function draw() {

  if (gamestate == 'menu') {

    image(posterImage, 0, 0, width, height); //Displaying menu screen if gamestate is menu

    if (!title_screen_audio.isPlaying())

      {

        title_screen_audio.play(); //Plays menu music

      }

  }

  if (gamestate == 'playing') {

    title_screen_audio.stop(); //Stops menu music when gamestate is playing

    if (!playing_screen_audio.isPlaying())

      {

        playing_screen_audio.play(); //Plays battle music

      }

    background(1, 22, 64);

    player.show();

​

    for (let star of stars) {

      star.show(); //Displaying stars

    }

​

    // Add enemies randomly

    if (frameCount % (60 / enemySpawnRate) == 0) {

      let enemy = new Enemy(random(width-50), -50, random(1, 4));

      enemies.push(enemy);

    }

​

    for (let i = 0; i < bullets.length; i++) {

      bullets[i].update(); //Adding velocity to bullets

      bullets[i].show(); //Displaying bullets

      for (let j = 0; j < enemies.length; j++) {

        let enemyHitbox = enemies[j].getHitbox(); //Initializing enemies with hitbox

        if (bullets[i].hits(enemyHitbox)) {

          bullets.splice(i, 1); //Remove bullets when it hits an enemy

          enemies[j].hits(); //Registers hit to enemy

          score += 1; //Incremements score on hit

          enemies.splice(j, 1); // remove the enemy object from the array

          break;

        }

      }

    }

​

    for (let i = 0; i < enemies.length; i++) {

      enemies[i].update(); //Makes enemies fall

      enemies[i].show(); //Displays enemies

    }

​

    let anyEnemyReachedBottom = false; // flag to indicate if any enemy has     reached the bottom

    for (let i = 0; i < enemies.length; i++) {

      if (enemies[i].reachedBottomFlag) {

        anyEnemyReachedBottom = true; //Turns true when enemy reaches bottom

        break;

      }

    }

​

    if (anyEnemyReachedBottom) {

      gamestate = 'gameover'; //Sets gamestate to gameover once enemy reaches the bottom

    }

​

    textSize(20);

    strokeWeight(1);

    textFont(font);

    fill(255);

    text("Score: " + score, 10, 30); //Displays score at top left

  }

​

  if (gamestate == 'gameover') {

    playing_screen_audio.stop(); //Stops battle music

    if (!end_screen_audio.isPlaying())

      {

        end_screen_audio.play(); //Plays defeat music

      }

    background(1, 22, 64);

    for (let star of stars) {

      star.show(); //Displays stars

    }

    textSize(30);

    strokeWeight(1);

    fill(255);

    textFont(font);

    text("Game Over", width / 2 - 80, height / 2 - 20);

    text("Score: " + score, width / 2 - 65, height / 2 + 20);

    text("Press Space to retry!", width / 2 - 150, height / 2 + 60);

  }

  timeElapsed += deltaTime / 1000;

  if (timeElapsed >= 30) { // increase spawn rate every 30 seconds

    enemySpawnRate++;

    timeElapsed = 0;

  }

}

function mouseClicked() {

  if (gamestate == 'menu') {

    gamestate = 'playing'; //Changes gameststate on mouseclick

  }

  if (gamestate == 'playing') {

    let bullet = new Bullet(mouseX + 3, height - 20, 10);

    bullets.push(bullet); //Fires bullet on every click

    laser_sound_effect.play(); //Plays laser sound on every click

  }

}

​

function keyPressed(){

  if (key == ' ' && gamestate == 'gameover'){

    score = 0;

    bullets = [];

    enemies = [];

    restartGame();

    end_screen_audio.stop(); //Restarts game by pressing space on game over screen

  }

}

​

function restartGame() {

  gamestate = 'playing';

  enemySpawnRate = 1;

}

​

class Bullet {

  //Setting variables

  constructor(x, y, velocity) {

    this.x = x;

    this.y = y;

    this.velocity = velocity;

    this.size = 20; 

  }

​

  update() {

    this.y -= this.velocity; //Fires bullet upward

  }

​

  show() {

    image(laser, this.x - this.size/2, this.y - this.size/2, this.size, this.size); //Laser image

  }

​

  hits(hitbox) {

    let d = dist(this.x, this.y, hitbox.x + hitbox.width/2, hitbox.y + hitbox.height/2);

    if (d < (this.size + hitbox.width)/2) {

      return true; //Hitbox registration

    } else {

      return false;

    }

  }

}

​

class Spaceship {

  constructor(x,y) {

    this.x = x;

    this.y = y; // Setting variables

  }

  show(){

    //Prevents fighter from going out of bounds

    if (mouseX - 30 < 0)

      {

        image(fighter,0,height-50,this.x,this.y);

      }

    else if (mouseX - 30 > width)

      {

        image(fighter,width - this.x,height-50,this.x,this.y);

      }

    else

      {

        image(fighter,mouseX-30,height-50,this.x,this.y);

      }

  }

}

//Creates stars in background

class Star {

  constructor(x, y, size) {

    this.x = x;

    this.y = y;

    this.size = size;

  }

​

  show() {

    stroke(255);

    strokeWeight(this.size);

    point(this.x, this.y);

  }

}

​

class Enemy {

  constructor(x, y, velocity) {

    this.x = x;

    this.y = y;

    this.velocity = velocity;

    this.size = 30;

    this.reachedBottomFlag = false; // flag to indicate if this enemy has reached the bottom

  }

​

  update() {

    this.y += this.velocity;

    if (this.y >= height) {

      this.reachedBottomFlag = true; //Detects if enemy has reached bottom

    }

  }

​

  show() {

    image(enemy, this.x, this.y, this.size, this.size); //Creating enemies images

  }

​

  hits() {

    this.velocity = 0; //Sets velocity to 0 on hit

  }

​

  getHitbox() {

    return {

      x: this.x,

      y: this.y,

      width: this.size,

      height: this.size //Creates hitbox of enemies

    }

  }

} 

​