title: Locating Bounding 2D Entities
body: <p>Given a point and a set of arbitrary 2D entities (circles, polygons, lines, polylines, arcs, etc.), does anyone know of existing strategies to:</p>
  
  <ol>
  <li><p>Determine if the point is enclosed (bounded) by any combination of entities? I know that it is easy enough to do an 'inside' test on the closed shapes, but this won't always give me what I want - particularly with nested or intersecting shapes.</p></li>
  <li><p>Find the smallest (closest?) set of lines / entities that form a closed polygon around my point? (think of a flood-fill, but without relying on colour)</p></li>
  </ol>