title: How to work out the angle between two 2D vectors using cross product?
body: <p>So here's a link for the same question but the best answer doesn't explain it fully:</p>
  
  <p><a href="https://stackoverflow.com/questions/4859306/rotate-sprite-to-mouse-position">Rotate Sprite to Mouse Position</a></p>
  
  <p>It's the cross product that I'm stuck with, since the formula in that link can only be applied in mathematics outside of computing. </p>
  
  <p>What is the actual formula to calculate the cross product in computing form?
  If you can post it as C++ code that would be great.</p>
  
  <p>Keep in mind I'm looking for the cross product between 2 2D vectors, not 3D.</p>