About Solution.x_max and y_max in Irregular problem type

[bbeaulant]

Hello,

In irregular problem type, the solution propose 2 computed values : x_max and y_max. These values represents the max x and y of the last bin.

But these values ​​are only usable if the placement direction chosen by the algorithm is from Left to Right and from Bottom to Top. Otherwise, these maximums are set to bin max.

Several questions:

• Can't these values ​​be adapted to the direction? x_min and y_min ?
• Wouldn't it be interesting to have control over the possible directions?

[fontanf]

Hi,

Can't these values ​​be adapted to the direction? x_min and y_min ?

It's easy to add x_min and y_min values inside the Solution class. The question is "is it useful?". Considering how the bin-packing-with-leftovers objective is currently defined, solutions almost always have x_min = 0 and y_min = 0.

Wouldn't it be interesting to have control over the possible directions?

I don't know. Are enough people interested in this to make it worth adding and maintaining such an option?

[bbeaulant]

The question is "is it useful?"

Yes, it could be. If min represents the min coord of items in bin space as max does.
These values can be used to display the last bin items bounding box or compute its compactness. And with only maximums it can only be done if direction is LeftToRightAndBottomToTop.

Are enough people interested in this to make it worth adding and maintaining such an option?

Yes. Most of concurrent tools always align result in the same corner or offer the ability to configure it.
This could be useful for the operator on a CNC if the cut parts are always in the same corner. Even if this may degrade the surface optimization a little.

[fontanf]

One possibility is to add a parameter to the Instance that indicates how the leftover is computed with the BinPackingWithLeftover objective: right/top/left/bottom rectangle, top-right/top-left/bottom-right/bottom-left L-shape (current is top-right L-shape)

[bbeaulant]

That seems like an interesting idea.
So it would only change the alignment "direction" for the last bin?
Is this a complex idea to implement?

[bbeaulant]

Here is one example where x_min of forcing direction could be useful 😉

[fontanf]

I added the x_min and x_max methods in 6d83c0e

[bbeaulant]

Nice, I will check that 👍

[fontanf]

I close this issue because the x_min and x_max attributes have been added and the request to handle a user provided origin is tracked in issue #262