title: Selecting a series of line segments in C#
body: <p>I'm trying to create a very simple feature for a home-brew computer-aided-machining software application I'm working on.  Basically, I've drawn out some tool-paths that will tell a milling machine where to travel.  So, imagine I have 3 sets of line segments, each with say 100 individual line segments, each contained within its own List, as follows:</p>
  
  <pre><code>List&lt;PointF&gt; points = new List&lt;PointF&gt;();
  List&lt;PointF&gt; pointsOffsetHigh = new List&lt;PointF&gt;();  
  List&lt;PointF&gt; pointsOffsetLow = new List&lt;PointF&gt;(); 
  </code></pre>
  
  <p>Let's say they are criss-crossing one another on the screen, and I want each one to be treated as its own object when I click on any line segment within it.  How would I approach that?  I can already select an individual line segment using this excellent example from StackOverflow:<a href="https://stackoverflow.com/questions/10768570/graphic-drawline-draw-line-and-move-it">Graphic - DrawLine - draw line and move it</a></p>
  
  <p>Once I select a series of line segments, I'm going to see where it intersects with another series of line segments, and then erase one half of it.  It's something very basic to any CAD program, but something that looks so simple on the screen has so much complexity behind it.  </p>
  
  <p>If anyone can help, I'd appreciate it.  Code, general approach, I'll take anything.</p>