Allow items to be stacked (fixes #11)

Packer.php

@@ -284,6 +284,23 @@ public function packIntoBox(Box $aBox, ItemList $aItems) {
  $layerWidth = max($itemLength, $layerWidth);
  }
  $layerDepth = max($layerDepth, $itemToPack->getDepth()); //greater than 0, items will always be less deep
+
+ //allow items to be stacked in place within the same footprint up to current layerdepth
+ $maxStackDepth = $layerDepth - $itemToPack->getDepth();
+ while(!$aItems->isEmpty()) {
+ $potentialStackItem = $aItems->top();
+ if ($potentialStackItem->getDepth() <= $maxStackDepth &&
+ $potentialStackItem->getWeight() <= $remainingWeight &&
+ $potentialStackItem->getWidth() <= $itemToPack->getWidth() &&
+ $potentialStackItem->getLength() <= $itemToPack->getLength()) {
+ $remainingWeight -= $potentialStackItem->getWeight();
+ $maxStackDepth -= $potentialStackItem->getDepth();
+ $packedItems->insert($aItems->extract());
+ }
+ else {
+ break;
+ }
+ }
  }
  else {
  if ($remainingWidth >= min($itemWidth, $itemLength) && $layerDepth > 0) {

tests/PackerTest.php

@@ -350,6 +350,17 @@ public function testIssue9() {
  self::assertEquals(1, $packedBoxes->count());
  }
 
+ public function testIssue11() {
+ $packer = new Packer();
+ $packer->addBox(new TestBox('4x4x4Box', 4, 4, 4, 4, 4, 4, 4, 100));
+
+ $packer->addItem(new TestItem('BigItem', 2, 2, 4, 1), 2);
+ $packer->addItem(new TestItem('SmallItem', 1, 1, 1, 1), 32);
+ $packedBoxes = $packer->pack();
+
+ self::assertEquals(1, $packedBoxes->count());
+ }
+
  public function testIssue13() {
  $packer = new Packer();
  $packer->addBox(new TestBox('Le petite box', 12, 12, 12, 10, 10, 10, 10, 1000));