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Factor out orientation selection to a dedicated class
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| <?php | ||
| /** | ||
| * Box packing (3D bin packing, knapsack problem) | ||
| * @package BoxPacker | ||
| * @author Doug Wright | ||
| */ | ||
| namespace DVDoug\BoxPacker; | ||
|
|
||
| use Psr\Log\LoggerAwareInterface; | ||
| use Psr\Log\LoggerAwareTrait; | ||
|
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||
| /** | ||
| * Figure out orientations for an item and a given set of dimensions | ||
| * @author Doug Wright | ||
| * @package BoxPacker | ||
| */ | ||
| class OrientatedItemFactory implements LoggerAwareInterface | ||
| { | ||
| use LoggerAwareTrait; | ||
|
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| /** | ||
| * Get the best orientation for an item | ||
| * @param Box $box | ||
| * @param Item $item | ||
| * @param OrientatedItem|null $prevItem | ||
| * @param Item|null $nextItem | ||
| * @param int $widthLeft | ||
| * @param int $lengthLeft | ||
| * @param int $depthLeft | ||
| * @return OrientatedItem|false | ||
| */ | ||
| public function getBestOrientation(Box $box, Item $item, OrientatedItem $prevItem = null, Item $nextItem = null, $widthLeft, $lengthLeft, $depthLeft) { | ||
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| $possibleOrientations = $this->getPossibleOrientations($item, $prevItem, $widthLeft, $lengthLeft, $depthLeft); | ||
| $usableOrientations = $this->getUsableOrientations($possibleOrientations, $box, $item, $prevItem, $nextItem); | ||
|
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| $orientationFits = []; | ||
| /** @var OrientatedItem $orientation */ | ||
| foreach ($usableOrientations as $o => $orientation) { | ||
| $orientationFit = min($widthLeft - $orientation->getWidth(), $lengthLeft - $orientation->getLength()); | ||
| $orientationFits[$o] = $orientationFit; | ||
| } | ||
|
|
||
| if (!empty($orientationFits)) { | ||
| asort($orientationFits); | ||
| reset($orientationFits); | ||
| $bestFit = $usableOrientations[key($orientationFits)]; | ||
| $this->logger->debug("Selected best fit orientation", ['orientation' => $bestFit]); | ||
| return $bestFit; | ||
| } else { | ||
| return false; | ||
| } | ||
| } | ||
|
|
||
| /** | ||
| * Find all possible orientations for an item | ||
| * @param Item $item | ||
| * @param OrientatedItem|null $prevItem | ||
| * @param int $widthLeft | ||
| * @param int $lengthLeft | ||
| * @param int $depthLeft | ||
| * @return OrientatedItem[] | ||
| */ | ||
| public function getPossibleOrientations(Item $item, OrientatedItem $prevItem = null, $widthLeft, $lengthLeft, $depthLeft) { | ||
|
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| $orientations = []; | ||
|
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| //Special case items that are the same as what we just packed - keep orientation | ||
| if ($prevItem && $prevItem->getItem() == $item) { | ||
| $orientations[] = new OrientatedItem($item, $prevItem->getWidth(), $prevItem->getLength(), $prevItem->getDepth()); | ||
| } else { | ||
|
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| //simple 2D rotation | ||
| $orientations[] = new OrientatedItem($item, $item->getWidth(), $item->getLength(), $item->getDepth()); | ||
| $orientations[] = new OrientatedItem($item, $item->getLength(), $item->getWidth(), $item->getDepth()); | ||
|
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| //add 3D rotation if we're allowed | ||
| if (!$item->getKeepFlat()) { | ||
| $orientations[] = new OrientatedItem($item, $item->getWidth(), $item->getDepth(), $item->getLength()); | ||
| $orientations[] = new OrientatedItem($item, $item->getLength(), $item->getDepth(), $item->getWidth()); | ||
| $orientations[] = new OrientatedItem($item, $item->getDepth(), $item->getWidth(), $item->getLength()); | ||
| $orientations[] = new OrientatedItem($item, $item->getDepth(), $item->getLength(), $item->getWidth()); | ||
| } | ||
| } | ||
|
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||
| //remove any that simply don't fit | ||
| return array_filter($orientations, function(OrientatedItem $i) use ($widthLeft, $lengthLeft, $depthLeft) { | ||
| return $i->getWidth() <= $widthLeft && $i->getLength() <= $lengthLeft && $i->getDepth() <= $depthLeft; | ||
| }); | ||
| } | ||
|
|
||
| /** | ||
| * @param OrientatedItem[] $possibleOrientations | ||
| * @param Box $box | ||
| * @param Item $item | ||
| * @param OrientatedItem $prevItem | ||
| * @param Item $nextItem | ||
| * | ||
| * @return array | ||
| */ | ||
| protected function getUsableOrientations( | ||
| $possibleOrientations, | ||
| Box $box, | ||
| Item $item, | ||
| OrientatedItem $prevItem = null, | ||
| Item $nextItem = null | ||
| ) { | ||
| /* | ||
| * Divide possible orientations into stable (low centre of gravity) and unstable (high centre of gravity) | ||
| */ | ||
| $stableOrientations = []; | ||
| $unstableOrientations = []; | ||
|
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||
| foreach ($possibleOrientations as $o => $orientation) { | ||
| if ($orientation->isStable()) { | ||
| $stableOrientations[] = $orientation; | ||
| } else { | ||
| $unstableOrientations[] = $orientation; | ||
| } | ||
| } | ||
|
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| $orientationsToUse = []; | ||
|
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| /* | ||
| * We prefer to use stable orientations only, but allow unstable ones if either | ||
| * the item is the last one left to pack OR | ||
| * the item doesn't fit in the box any other way | ||
| */ | ||
| if (count($stableOrientations) > 0) { | ||
| $orientationsToUse = $stableOrientations; | ||
| } else if (count($unstableOrientations) > 0) { | ||
| $orientationsInEmptyBox = $this->getPossibleOrientations( | ||
| $item, | ||
| $prevItem, | ||
| $box->getInnerWidth(), | ||
| $box->getInnerLength(), | ||
| $box->getInnerDepth() | ||
| ); | ||
|
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| $stableOrientationsInEmptyBox = array_filter( | ||
| $orientationsInEmptyBox, | ||
| function(OrientatedItem $orientation) { | ||
| return $orientation->isStable(); | ||
| } | ||
| ); | ||
|
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| if (is_null($nextItem) || count($stableOrientationsInEmptyBox) == 0) { | ||
| $orientationsToUse = $unstableOrientations; | ||
| } | ||
| } | ||
|
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| return $orientationsToUse; | ||
| } | ||
| } | ||
|
|
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