fix gizmo bar wobbling

[buzzhuzz]

Description

Gizmo bar is wobbling at specific application window width range. This comes from a bar scaling calculations method: - new scale calculated for already scaled bar - scale stored as application settings loosing precision

Rework gizmo bar resizing code to remove feedback: - calculate scale factor based on unscaled bar size

Screenshots/Recordings/Graphs

Screen recording demonstrating the problem

https://github.com/user-attachments/assets/3c8de68d-ef6b-44e9-b41c-5f936047989d

Tests

Manual tests with different window sizes

[yw4z]

i saw many linux users complain about this on discord and reddit. maybe more testers needed also can you check icons are still pixel perfect on regular toolbar size on different window widths related commit with this https://github.com/SoftFever/OrcaSlicer/pull/4552

[igiannakas]

I've had a similar issue on MacOS. Will test this, thank you for the effort in fixing it!!!

[igiannakas]

It works but on Mac OS it makes the bar too small:

[buzzhuzz]

@igiannakas , thanks for your testing

@yw4z, thanks for your comment. Looking at your changes I see that windows builds are still broken.

I'll update PR once fix MacOS and Windows builds.

[buzzhuzz]

Upon code studying I found that #4552 only affects windows build. After that I've installed windows test VM, download Orca release bulid and found that gizmo bar icons are slightly smaller and much sharper:

• Current Linux implementation:
• Updated Linux implemenattion (windows-like):

Gizmo bar scaling code now unified across all platforms and shall produce exact result across all three.

[igiannakas]

Tested on MacOS - think its working well!

[buzzhuzz]

Added commentary. Slightly reorganized code to minimize diff output.

[SoftFever]

Hi @buzzhuzz

A heads up, both user and I found the flicking is worse after this change. I have reverted the change for now. I have also committed a workaround fix(cbda70a), it seems working fine now.