Assigning categories to game objects

Now that we have the physics categories, we need to go back through our existing game objects and assign the categories to the physics bodies. We will start with the Player class.

The player

Open Player.swift and add the following code at the bottom of the init function:

self.physicsBody?.categoryBitMask = 
    PhysicsCategory.penguin.rawValue 
self.physicsBody?.contactTestBitMask = 
    PhysicsCategory.enemy.rawValue | 
    PhysicsCategory.ground.rawValue | 
    PhysicsCategory.powerup.rawValue | 
    PhysicsCategory.coin.rawValue 
self.physicsBody?.collisionBitMask = 
    PhysicsCategory.ground.rawValue 

We assigned the penguin physics category to the Player physics body, and used the contactTestBitMask property to set up contact logic tests with enemies, the ground, Power-ups, and coins. We used the collisionBitMask to make the penguin only bounce off the ground while gliding through other game objects.

Also...