let playerSize = 100;

let bulletSize = 5;

let bullets = [];

let enemies = [];

let asteroids = [];

let spawnEnemyInterval, spawnAsteroidInterval;

let spaceship;

​

function preload(){

  spaceship = loadImage("spaceShip.png");

}

​

function setup() {

  createCanvas(400, 600);

  playerX = width / 2;

  playerY = height - 50;

  spawnEnemyInterval = setInterval(spawnEnemy, 1500);

  spawnAsteroidInterval = setInterval(spawnAsteroid, 2000);

}

​

function draw() {

  background(0);

​

  // move the player with arrow keys and wrap around the screen

  if (keyIsDown(LEFT_ARROW)) {

    playerX -= 5;

    if (playerX < 0) {

      playerX = width;

    }

  }

  if (keyIsDown(RIGHT_ARROW)) {

    playerX += 5;

    if (playerX > width) {

      playerX = 0;

    }

  }

​

  // draw the player

  fill(255);

    image(spaceship, playerX - playerSize / 2, playerY - playerSize / 2, playerSize, playerSize);

​

  // move and draw the bullets

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

    bullets[i].y -= 10;

    fill(255, 255, 0);

    ellipse(bullets[i].x, bullets[i].y, bulletSize);

    // remove the bullet if it goes off the screen

    if (bullets[i].y < 0) {

      bullets.splice(i, 1);

    } else {

      // check for collisions between bullet and enemy

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

        if (dist(bullets[i].x, bullets[i].y, enemies[j].x, enemies[j].y) < playerSize) {

          // bullet hit an enemy, remove both

          bullets.splice(i, 1);

          enemies.splice(j, 1);

          break;

        }

      }

    }

  }

​

  // move and draw the enemies

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

    enemies[i].y += 5;

    fill(255, 0, 0);

    ellipse(enemies[i].x, enemies[i].y, playerSize/4);

    // remove the enemy if it goes off the screen

    if (enemies[i].y > height) {

      enemies.splice(i, 1);

    } else {

      // check for collisions between player and enemy

      if (dist(playerX, playerY, enemies[i].x, enemies[i].y) < playerSize/4) {

        // game over

        textSize(32);

        textAlign(CENTER);

        fill(255);

        text("GAME OVER", width / 2, height / 2);

        noLoop();

        clearInterval(spawnEnemyInterval);

        clearInterval(spawnAsteroidInterval);

      }

    }

  }

​

  // move and draw the asteroids

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

    asteroids[i].y += 3;

    fill(255);

    ellipse(asteroids[i].x, asteroids[i].y, playerSize/4);

    // remove the asteroid if it goes off the screen

    if (asteroids[i].y > height) {

      asteroids.splice(i, 1);

    } else {

      // check for collisions between player and asteroid

      if (dist(playerX, playerY, asteroids[i].x, asteroids[i].y) < playerSize/4) {

        //player hit an asteroid, reduce player size and remove asteroid

playerSize -= 5;

asteroids.splice(i, 1);

}

}

}

}

​

function keyPressed() {

if (keyCode === 32) { // spacebar

bullets.push({

x: playerX,

y: playerY - playerSize / 2 - bulletSize / 2

});

}

}

​

function spawnEnemy() {

enemies.push({

x: random(width),

y: -playerSize

});

setTimeout(spawnEnemy, random(1500, 2000));

}

​

function spawnAsteroid() {

asteroids.push({

x: random(width),

y: -playerSize

});

setTimeout(spawnAsteroid, random(2000, 3000));

}

​

spawnEnemy();

spawnAsteroid();

​