Improved: Barcode scaling for PDF417 and Code128

[daanggc]

A DHL label that I use crashed on the PDF417 barcode and the Code128 barcodes are too long to fit on the page.

DHL uses ^BY2^B7N,6.7,5,,30,N that has the following issues PDF417:

• ^BY2 defines a width of 2 but the code was hard set to 3.
• 6.7 defines a rowHeight but as that is not an int, we default to 10.
• ,,30 defines no columns for 30 rows, which is hard for the library used.

DHL uses >5 in the Code128 barcode. They do that to select the limited Code128C charset for that part of the barcode to have a shorter result, but we don't support that. A good fallback is the TYPE.CODE128 option, which automatically optimizes the charset usage and comes very close to the expected result.

(Left: after with Labelary overlay, right: before)

EDIT 05-04-2024: After the last vertical scaling changes this is the result compared to the real print:

[daanggc]

Thanks to reportingissue I found more improvements for the vertical scaling, it looks even better now.

I also added a PDF417 barcode test in the list, here it is with the real print and the overlay:

As long as the rows and columns are defined, it's very good. The visible differences are basically always related to the ZXing library having to guess the row/column combination.

[daanggc]

Hardened the Code128 drawer code a bit more and improved GS1 support, added an example and this is the generated and printed result of that:

You can preview it here: https://binarykits.dvdg.nu/