[Bug] Resizing to 16/9 with `Page Size` leaves massive margins

[Vekhir]

Describe the bug

In the menu OpenBoard -> Page Size, there is an option to resize the page to 16/9. Using it on imported PDFs with that ratio (which still get a custom size) leads to large margins on each side. This happens on single and dual-monitor setups.

To Reproduce

1. Import test_resize (2 slides á 1920x1080)
2. Click on OpenBoard -> Page Size -> Wide Size (16/9)
3. Zoom out to see border

Expected behavior

The slides should fit exactly inside the border

Actual behavior

Resizing to 16/9, the slide has about a 10% margin on each side and is centered in the middle.

Resizing to 4/3 has a similar behaviour. The slide size does not change when resizing between 16/9 and 4/3 - only the border changes.

Additional resources

Test data: test_resize.zip

Screenshots

After 1. import:

After 2. resize wide (16/9):

After zooming out (16/9):

After resize regular (4/3):

After zooming out (4/3):

Context

• reproducibility : systematic
• OpenBoard version :
  • bug happens with : 1.7.1, 1665e2e570e5e76c75d9e8a4b7e9a3f0c5071736 (dev)
  • didn't check : 1.6.4 1.7.0
• OS :
  • bug happens with : Linux (own tests) Windows (inferred from https://github.com/OpenBoard-org/OpenBoard/issues/1006#issuecomment-2154739723)
  • didn't check :macOS
• Installation source : own build via AUR

Additional context

OS: Arch Linux Kernel: Linux 6.9.3-arch1-1

a) number and resolution of monitors : 2 x 1920x1080, b) number and resolution of monitors: 1 x 1920x1080

[gzavarise]

I got the same problem on MAC and a Wacom Cintiq 16. This bug is a real tragedy, since all my files now are not correctly visible. however the generated pdf ik still ok. I enclose a Cintiq 16 screen screenshot (wrong view), and the one of the pdf generated file (still ok).

[Vekhir]

@gzavarise I believe you are encountering a different issue, namely #846. Note how your image is cut off by grey borders, but no significant scaling is happening like in my screenshots above. If you are technically inclined, you may try out PR #901.