The power of the physics body

GameScene.swift

// omitted
class GameScene: SKScene {
    // omitted
    func setupPlayer() {
        // omitted
        
        // we create a physics body with the size of the player
        player.physicsBody = SKPhysicsBody(rectangleOfSize: player.size)
        
        // yes, it's that simple to be affected by gravity
        player.physicsBody?.affectedByGravity = true
        
        // make the player collide with the floor
        player.physicsBody?.categoryBitMask = Physics.Character
        player.physicsBody?.collisionBitMask = Physics.Character
        
        // this add the player to the scene in order to appear in the screen
        addChild(player)
    }
    
    func setupFloor() {
        // omitted
        
        // we create a physics body with the size of the floor
        floor.physicsBody = SKPhysicsBody(rectangleOfSize: floor.size)
        
        // the floor doesn't move, right? =)
        floor.physicsBody?.affectedByGravity = false
        
        // make the floor collide with the player
        floor.physicsBody?.categoryBitMask = Physics.Character
        floor.physicsBody?.collisionBitMask = Physics.Floor
        
        // this add the floor to the scene in order to appear in the screen
        addChild(floor)
    }
}