Initial game code

game.coffee

enemies = null
land = null
bullets = null
explosions = null
fireRate = 500
nextFire = 0
nextEnemy0 = 0
enemyRate0 = 400

preload = ->
  game.load.image('sea', 'sea.png')
  game.load.image('bullet', 'bullet-small.png')
  game.load.image('enemy0', 'enemy0.png')
  game.load.spritesheet('explosion', 'explosion.png', 32, 32, 6)
  return

fire = ->
  if (game.time.now > nextFire && bullets.countDead() > 0)
    nextFire = game.time.now + fireRate
    bullet = bullets.getFirstExists(false)
    bullet.reset(400, 590)
    bullet.rotation = game.physics.arcade.moveToPointer(bullet, 100, game.input.activePointer)

collisionHandler = (bullet, enemy) ->
  bullet.kill()
  enemy.kill()
  explosion = explosions.getFirstExists(false)
  explosion.reset(enemy.body.x, enemy.body.y)
  explosion.play('explosion', 30, false, true)

create = ->
  land = game.add.tileSprite(0, 0, 800, 600, 'sea')

  enemies = game.add.group()
  enemies.enableBody = true
  enemies.physicsBodyType = Phaser.Physics.ARCADE
  enemies.createMultiple(30, 'enemy0', 0, false)
  enemies.setAll('anchor.x', 0.5)
  enemies.setAll('anchor.y', 0.5)
  enemies.setAll('outOfBoundsKill', true)
  enemies.setAll('checkWorldBounds', true)

  bullets = game.add.group()
  bullets.enableBody = true
  bullets.physicsBodyType = Phaser.Physics.ARCADE
  bullets.createMultiple(30, 'bullet', 0, false)
  bullets.setAll('anchor.x', 0.5)
  bullets.setAll('anchor.y', 0.5)
  bullets.setAll('outOfBoundsKill', true)
  bullets.setAll('checkWorldBounds', true)

  explosions = game.add.group()
  explosions.createMultiple(50, 'explosion')
  explosions.forEach(((explosion) ->
    explosion.anchor.x = 0
    explosion.anchor.y = 0
    explosion.animations.add 'explosion'
  ), this)
  return

update = ->
  fire() if game.input.activePointer.isDown
  land.tilePosition.y += 0.5
  game.physics.arcade.overlap(bullets, enemies, collisionHandler, null, this)

render = ->
  #console.log "#{game.time.now} #{nextEnemy0} #{enemies.countDead()}"
  if game.time.now > nextEnemy0 and enemies.countDead() > 0
    nextEnemy0 = game.time.now + enemyRate0
    enemy = enemies.getFirstExists(false)
    enemy.reset(20 + Math.random() * 760, 0)
    enemy.body.velocity.y = 30 + Math.random() * 30

  return


game = new Phaser.Game(800, 600, Phaser.AUTO, 'game-container', { preload: preload, create: create, update: update, render: render })