title: Draw line in picturebox and redraw on zoom
body: <p>I'm drawing a line in a picturebox this way:</p>
  
  <pre><code>horizontalstart = new Point(0, e.Y); //Start point of Horizontal line.
  horizontalend = new Point(picbox_mpr.Width, e.Y); //End point of Horizontal line.
  verticalstart = new Point(e.X, 0); //Start point of Vertical line
  verticalend = new Point(e.X, picbox_mpr.Height); //End point of Vertical line.
  </code></pre>
  
  <p>Then on the paint event I do this:</p>
  
  <pre><code>e.Graphics.DrawLine(redline, horizontalstart, horizontalend); //Draw Horizontal line.
  e.Graphics.DrawLine(redline, verticalstart, verticalend); //Draw Vertical line.
  </code></pre>
  
  <p>Pretty simple, now, my image can zoom and here's where I struggle..</p>
  
  <p>How do I keep the line in the same spot that was drawn even if I zoom the image?</p>