title: How to get row and column from index?
body: <p>I'm drawing a <em>HUGE</em> blank here.</p>
  
  <p>Everything I've found is about getting an index from a given row and column, but how do I get a row and a column from an index?</p>
  
  <p>The row is easy: <code>(int)(index / width)</code>.</p>
  
  <p>My brain is suffering massive bleed trying to compute the column.</p>
  
  <p>Shame on me.</p>