Text rendering regression with femtovg renderer

[bjorn]

While testing the current git master for the upcoming Slint 1.8 release, I noticed that the fonts look jagged. I started going back to older Slint versions until I arrived at Slint 1.4.1, which is the last version where fonts looked good (so it appears to be a regression in Slint 1.5.0).

Slint 1.4.1 (slightly blurry but smooth fonts):

Slint 1.5.0 to current git (fonts look jagged):

(notice how the right leg of the "n" is one pixel further down than the left leg)

I'm on Linux (Fedora), using the winit backend with the femtovg renderer.

[bjorn]

Just tested this with the todo example. I see it there as well when using renderer-femtovg. I also tested renderer-software, and then the fonts look fine.

renderer-femtovg (git):

renderer-software (git):

renderer-femtovg (1.4.1):

[Enyium]

(notice how the right leg of the "n" is one pixel further down than the left leg)

You seem to mean the n of "Transactions".

This is a screenshot of SlintPad (v1.7.2, using FemtoVG):

I find it very strange that the bars of the Ts that should be vertical aren't always perfectly vertical. This rendering issue depends on the font size, the preview box size etc.

[tronical]

This is likely a consequence of #5177 . Perhaps additional alignment is needed.

[expenses]

Possibly related to #9310?