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font rendering is poor #233
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I just came from the slint issue. I believe that the problem is poor handling of high or mixed window scale factors (aka DPI or how close the pixels are on a screen). I'm using Wayland with a scale factor of 1.566667. When the text demo first opens it draws the first frame then stalls for a second or so. The fonts looks fine albeit blurry, but then once it responds to the window scale factor (I think it just defaults to 1 until notified otherwise) then it looks bad.
Initial load. Fine but being upscaled 1.5x so it's blurry.
Subsequent draws. Really messed up.
and finally here's what it looks like when I set the scale factor in hyprland (my linux window manager) to 1. Looks fine :)
Looks like it might be snapping glyphs to logical pixels rather than physical pixels...
Up to version 0.17, fonts were rendered at high resolution, at least on macOS HiDPI displays, so I think this issue arose due to changes made after that point.
I recommend enabling the swash feature in Cargo to get swash rasterized glyphs, which looks significantly better.
Please give it a try and let us know. (Next Slint release also enables it)
Reacted by sumibi-yakitori and josefemtovg = "0.17"
femtovg = { version = "0.20", features = [ "swash" ] }
Unfortunately, it doesn't seem to be improving.
Skia:
Femtovg
As seen in the images. You can really see it with the word "Keyboard". The last release of cosmic-text was August last year. It might be worth trying their git directly as I recall cosmic desktop had similar issues but recently seems to be much better.