(function() {
  if (typeof Mario === 'undefined')
  window.Mario = {};

  var Bcoin = Mario.Bcoin = function(pos) {
    Mario.Entity.call(this, {
      pos: pos,
      sprite: level.bcoinSprite(),
      hitbox: [0,0,16,16]
    });
  }

  Mario.Util.inherits(Bcoin, Mario.Entity);

  //I'm not sure whether it makes sense to use an array for vel and acc here
  //in order to keep with convention, or to just use a single value, since
  //it's literally impossible for these to move left or right.
  Bcoin.prototype.spawn = function() {
    sounds.coin.currentTime = 0.05;
    sounds.coin.play();
    this.idx = level.items.length;
    level.items.push(this);
    this.active = true;
    this.vel = -12;
    this.targetpos = this.pos[1] - 32;
  }

  Bcoin.prototype.update = function(dt) {
    if (!this.active) return;

    if (this.vel > 0 && this.pos[1] >= this.targetpos) {
      player.coins += 1;
      //spawn a score thingy.
      delete level.items[this.idx];
    }

    this.acc = 0.75;
    this.vel += this.acc;
    this.pos[1] += this.vel;
    this.sprite.update(dt);
  }

  Bcoin.prototype.checkCollisions = function() {;}

})();