particular constraints

[Elyos59]

Hi!

To begin with, I wanted to congratulate you for this very good work.

I have some packing restriction and I don't know how to implement it.

I have 4 kind of item :
1/ Not stackable & keep flat
2/ Not stackable & 3D rotation (useless for the moment)
3/ Stackable & keep flat (useless for the moment)
4/ Stackable & 3D rotation

For the moment, I focus on the 1st and the 4th kind of item.

The 1st can't have another item on it.
The 4th can have one or more items on it only if :

• same dimensions or less (an item 2x2 can have 2 items 1x1 or 1 item 1x2 or 1 item 2x1 or 1 item 2x2 on it)
  AND
• same weight or less (an item of 20kgs can have on it 3 items of 20 kgs or less each)

I think I have to use ConstrainedPlacementItem Class but I don't know how to cause of item below (dimensions/orientations/weight...)

Thanks for any help ;)

[dvdoug]

Hello @Elyos59

https://boxpacker.io/en/stable/advanced-usage.html#example-don-t-allow-batteries-to-be-stacked would probably a good starting point - that example loops through the already packed items to find relevant items that would cause stacking issues. You'd need to modify that to add on your particular additional constraints

[Elyos59]

Ok.

I tried that :

<?php
declare(strict_types=1);

namespace DVDoug\BoxPacker\Test;

use DVDoug\BoxPacker\Box;
use DVDoug\BoxPacker\ConstrainedPlacementItem;
use DVDoug\BoxPacker\PackedBox;
use DVDoug\BoxPacker\PackedItem;
use DVDoug\BoxPacker\Test\TestItem;

class NotStackableTestItem extends TestItem implements ConstrainedPlacementItem
{

	/**
	 *
	 * @param  Box            $box
	 * @param  PackedItemList $alreadyPackedItems
	 * @param  int            $proposedX
	 * @param  int            $proposedY
	 * @param  int            $proposedZ
	 * @param  int            $width
	 * @param  int            $length
	 * @param  int            $depth
	 * @return bool
	 */
	public function canBePacked(
        PackedBox $packedBox,
        int $proposedX,
        int $proposedY,
        int $proposedZ,
        int $width,
        int $length,
        int $depth
    ): bool {
        return ($proposedZ === 0);
	}
}

<?php
declare(strict_types=1);

namespace DVDoug\BoxPacker\Test;

use DVDoug\BoxPacker\Box;
use DVDoug\BoxPacker\ConstrainedPlacementItem;
use DVDoug\BoxPacker\PackedBox;
use DVDoug\BoxPacker\PackedItem;
use DVDoug\BoxPacker\Test\TestItem;

class StackableTestItem extends TestItem implements ConstrainedPlacementItem
{

	/**
	 *
	 * @param  Box            $box
	 * @param  PackedItemList $alreadyPackedItems
	 * @param  int            $proposedX
	 * @param  int            $proposedY
	 * @param  int            $proposedZ
	 * @param  int            $width
	 * @param  int            $length
	 * @param  int            $depth
	 * @return bool
	 */
	public function canBePacked(
        PackedBox $packedBox,
        int $proposedX,
        int $proposedY,
        int $proposedZ,
        int $width,
        int $length,
        int $depth
    ): bool {
        $alreadyPackedType = array_filter(
            iterator_to_array($packedBox->getItems(), false),
            function (PackedItem $item) {
                return $item->getItem() instanceof StackableTestItem;
            }
        );
		if(!count($alreadyPackedType)){
			return true;
		}
		/** @var PackedItem $alreadyPacked */
		foreach ($alreadyPackedType as $alreadyPacked) {
			if (
				$alreadyPacked->getZ() + $alreadyPacked->getDepth() === $proposedZ &&
				$proposedX >= $alreadyPacked->getX() && $proposedX <= ($alreadyPacked->getX() + $alreadyPacked->getWidth()) &&
				($proposedX + $this->getWidth()) <= ($alreadyPacked->getX() + $alreadyPacked->getWidth()) &&
				$proposedY >= $alreadyPacked->getY() && $proposedY <= ($alreadyPacked->getY() + $alreadyPacked->getLength()) &&
				($proposedY + $this->getLength()) <= ($alreadyPacked->getY() + $alreadyPacked->getLength()) &&
				$this->getWeight() <= $alreadyPacked->getItem()->getWeight()
				) {
				return true;
			}
		}
		return false;
	}
}

My box : 175 x 280 x 180 (width x length x depth)
My items :

• 2 not stackable / keep flat : 100 x 120 x 20
• 6 stackable / best fit : 55 x 280 x 30
• 4 stackable / best fit : 60 x 80 x 90

And it doesn't work.
It gives me 8 boxes while it fits in one box...

[Elyos59]

In my StackableTestItem Class I've changed :

if(!count($alreadyPackedType){
by
if($proposedZ === 0){

and now items are in 3 boxes.

[Elyos59]

Same items should be stacked together... =/

[Elyos59]

I've tried to pre-sort items like you said here : #218 (comment) and force NotStackableItem height to full box height but the result it's not better and NotStackableItem are not placed at first (even if they are first in my pre-sorted items array)

Result without my personnal classes :

These items fitted into 2 box(es)
Box : width 175 length 280 depth 180
Stackable Item was packed at co-ordinate (0, 0, 0) with width : 30, length : 280, depth : 55
Stackable Item was packed at co-ordinate (30, 0, 0) with width : 30, length : 280, depth : 55
Stackable Item was packed at co-ordinate (60, 0, 0) with width : 30, length : 280, depth : 55
Stackable Item was packed at co-ordinate (90, 0, 0) with width : 30, length : 280, depth : 55
Stackable Item was packed at co-ordinate (120, 0, 0) with width : 30, length : 280, depth : 55
Stackable Item was packed at co-ordinate (0, 0, 55) with width : 30, length : 280, depth : 55
Box : width 175 length 280 depth 180
Not Stackable Item was packed at co-ordinate (0, 0, 0) with width : 120, length : 100, depth : 180
Not Stackable Item was packed at co-ordinate (0, 100, 0) with width : 100, length : 120, depth : 180
Stackable Item was packed at co-ordinate (100, 100, 0) with width : 60, length : 80, depth : 90
Stackable Item was packed at co-ordinate (100, 100, 90) with width : 60, length : 80, depth : 90
Stackable Item was packed at co-ordinate (0, 220, 0) with width : 80, length : 60, depth : 90
Stackable Item was packed at co-ordinate (0, 220, 90) with width : 80, length : 60, depth : 90

[Elyos59]

I progress... a bit ...

<?php
declare(strict_types=1);

namespace DVDoug\BoxPacker\Test;

use DVDoug\BoxPacker\Box;
use DVDoug\BoxPacker\ConstrainedPlacementItem;
use DVDoug\BoxPacker\PackedBox;
use DVDoug\BoxPacker\PackedItem;
use DVDoug\BoxPacker\Test\TestItem;

class StackableTestItem extends TestItem implements ConstrainedPlacementItem
{

	/**
	 *
	 * @param  Box            $box
	 * @param  PackedItemList $alreadyPackedItems
	 * @param  int            $proposedX
	 * @param  int            $proposedY
	 * @param  int            $proposedZ
	 * @param  int            $width
	 * @param  int            $length
	 * @param  int            $depth
	 * @return bool
	 */
	public function canBePacked(
        PackedBox $packedBox,
        int $proposedX,
        int $proposedY,
        int $proposedZ,
        int $width,
        int $length,
        int $depth
    ): bool {
		$box = $packedBox->getBox();
		/* $boxWidth = $box->getInnerWidth();
		$boxLength = $box->getInnerLength(); */
		$boxDepth = $box->getInnerDepth();
		$weight = $this->getWeight();
        $stackablePackedType = array_filter(
            iterator_to_array($packedBox->getItems(), false),
            function (PackedItem $item) {
                return $item->getItem() instanceof StackableTestItem;
            }
        );
		if(count($stackablePackedType) == 0 && $proposedZ === 0){
			return true;
		}
		$stackablePositions = array();
		/** @var PackedItem $alreadyPacked */
		foreach ($stackablePackedType as $stackablePacked) {
			list($x_,$y_,$z_,$width_,$length_,$depth_,$weight_) = array($stackablePacked->getX(),$stackablePacked->getY(),$stackablePacked->getZ(),$stackablePacked->getWidth(),$stackablePacked->getLength(),$stackablePacked->getDepth(),$stackablePacked->getItem()->getWeight());
			if($width_>=$width && $length_>=$length && $weight_>=$weight && ($z_+$depth_+$depth)<=$boxDepth){
				foreach($stackablePositions as $s => $stackablePosition){
					if($stackablePosition[$s]["x"]==$x_ && $stackablePosition[$s]["y"]==$y_){
						if($stackablePosition[$s]["z"]>$z_+$depth_){
							$stackablePosition[$s]["z"]=$z_+$depth_;
						}
						continue;
					}
				}
				$stackablePositions[] = array("x"=>$x_,"y"=>$y_,"z"=>$z_+$depth_,"item"=>$stackablePacked);
			}
		}
		if(count($stackablePositions)){
			foreach($stackablePositions as $stackablePosition){
				if(
					$stackablePosition["z"] === $proposedZ &&
					$proposedX >= $stackablePosition["x"] && $proposedX <= ($stackablePosition["x"] + $stackablePosition["item"]->getWidth()) &&
					($proposedX + $width) <= ($stackablePosition["x"] + $stackablePosition["item"]->getWidth()) &&
					$proposedY >= $stackablePosition["y"] && $proposedY <= ($stackablePosition["y"] + $stackablePosition["item"]->getLength()) &&
					($proposedY + $length) <= ($stackablePosition["y"] + $stackablePosition["item"]->getLength())
				){
					return true;
				}
			}
		}else if($proposedZ === 0){
			return true;
		}
		return false;
	}
}

Always two boxes but the second one could fill the first. There is just one unfilled hole :

[Elyos59]

I'm tearing my hair out!

No way to understand why it doesn't work ?!