A more advanced camera

Our current camera is functional, but a little boring. It focuses exclusively on the player, which works all right, but could be significantly improved. For starters, as the designers of Defender realized, it is more important to put the focus of the camera in the direction the player is moving, instead of directly on the player. To accomplish this, we will add projected focus to our camera. That will look at the current velocity of the player's ship, and will move the camera forward in the direction of that velocity. There are times, however, when you may still want the focus of your camera behind the player. To help with this, we will add some camera attractors. Camera attractors are objects that draw the camera's attention toward them. If the enemy appears behind the player, it may be more important to move the camera back somewhat to help keep...