title: How can I find the difference between two angles?
body: <p>Given 2 angles in the range -PI -> PI around a coordinate, what is the value of the smallest of the 2 angles between them?</p>
  
  <p>Taking into account that the difference between PI and -PI is not 2 PI but zero.</p>
  
  <p><strong>Example:</strong></p>
  
  <p>Imagine a circle, with 2 lines coming out from the center, there are 2 angles between those lines, the angle they make on the inside aka <strong>the smaller angle</strong>, and the angle they make on the outside, aka the bigger angle. Both angles when added up make a full circle. Given that each angle can fit within a certain range, <strong>what is the smaller angles value, taking into account the rollover</strong></p>