title: iOS7 Sprite Kit how to calculate node position when anchor point is changed?
body: <p>I have a node of <strong>width</strong> by <strong>height</strong> pixels, and I want to put it at <strong>(X,Y)</strong> position that I know.  However, I also need to shift the anchor point (<strong>anchorX</strong>, <strong>anchorY</strong>) of this node arbitrarily.</p>
  
  <p>If I proceed to add the child without accounting for the anchor point, the child node is shifted. I'm trying to compensate for this shift and put the node exactly where I want it to go.</p>
  
  <p><strong>What equation can I use to account for the anchor point change when adding a node as child?</strong></p>
  
  <p>So far I'm using something like this, but I'm not sure of the minus signs.</p>
  
  <pre><code> node.center =   CGPointMake(X-width*(0.5-anchorX) ,Y-height*(0.5-anchorY));
  </code></pre>