How to test if a line segment intersects an axis-aligned rectange in 2D?

Question

How to test if a line segment intersects an axis-aligned rectange in 2D? The segment is defined with its two ends: p1, p2. The rectangle is defined with top-left and bottom-

Answer 1

Some sample code for my solution (in php):

// returns 'true' on overlap checking against an array of similar objects in $this->packed
public function checkForOverlaps(BinPack_Polygon $nItem) {
  $nX = $nItem->getLeft();
  $nY = $nItem->getTop();
  $nW = $nItem->getWidth();
  $nH = $nItem->getHeight();
  // loop through the stored polygons checking for overlaps
  foreach($this->packed as $_i => $pI) {
    if(((($pI->getLeft() - $nW) < $nX) && ($nX < $pI->getRight())) && ((($pI->getTop() - $nH) < $nY) && ($nY < $pI->getBottom()))) {
      return true;
    }
  }
  return false;
}