title: Can't subtract two CGPoint operands in Swift 3 error
body: <p>I’m developing a game in <code>Swift 3</code> with <code>SpriteKit</code>.</p>
  
  <p>I’m having some problems with the conditional below. </p>
  
  <pre><code>if (personaje.position - lastTouchLocation).length() &lt; pjPixelsPerSecond * CGFloat(dt){
      velocity = CGPoint.zero
  } else {
    moveSprite(sprite: personaje, velocity: velocity)
  }
  </code></pre>
  
  <p>I get the following error:</p>
  
  <blockquote>
    <p>Binary operator '-' cannot be applied to two 'CGPoint' operands. </p>
  </blockquote>
  
  <p>How can I subtract these two variables?</p>
  
  <p>And I got:</p>
  
  <pre><code>var personaje = SKSpriteNode(imageNamed: "personajee")
  var velocity = CGPoint.zero
  var lastTouchLocation = CGPoint.zero
  … 
  
  func sceneTouched (touchLocation: CGPoint) {
      lastTouchLocation = touchLocation
      movePjToLocation(location: touchLocation)
  
  }
  </code></pre>