title: Difference between boundary fill and flood fill
body: <p>I'm quite confused as to how either flood fill or boundary fill color areas. Specifically when multiple colors are in play.</p>
  
  <p>Let's say we have a polygon with a green border and a checkered interior (black and white). Which algorithm would fill the area correctly with green and why?</p>
  
  <p>Definition of flood fill from the book:</p>
  
  <blockquote>
    <p>Sometimes we want to fill in (or recolor) an area that is not defined within a single color boundary. We can pain such areas by replacing a specified interior color instead of searching for a particular boundary color. This fill procedure is called a flood-fill algorithm.</p>
  </blockquote>