Conversion between Box and DBox

[olcc]

Hello,
I expect Box to live in the dbu world, and DBox to live in the um world, but describe the same entity.
Therefore, I expect pya.Box(pya.DBox(5)).width() to give 5000 if the dbu is 1 nm, but it gives 6 (which is weird).
In the same way, I expect pya.DBox(pya.Box(5000)).width() to give 5 if the dbu is 1 nm, but it gives 5000.0.
Olivier

[klayoutmatthias]

Hi @olcc,

No, that is not how it works. Box uses integer coordinates and DBox uses float-point coordinates. The use for DBU and micron is convention, not something that is enforced by the Box or DBox object.

For example:

Cell.bbox -> gives a DBU-unit box
Cell.dbbox -> gives a micron-unit box

So the Cell does the conversion, not the box.

If you want to convert, you can use

dbox_in_um = CplxTrans(dbu) * box_in_dbu
box_in_dbu = CplxTrans(dbu).inverted() * dbox_in_um

But it's easier to just stay in the same coordinate system consistently. Most datapaths are supported for both floating-point and integer types. The only exception is the Region class which is only available in integer-units.