Bad font rendering when fractionally scaled

[flukejones]

The screenshot demonstrates the issue. Fractional scaling is 125% here. It happens on most scales except integer.

Not sure what other info is valuable. This does happen in both KDE and Cosmic.

[XV-02]

Can you provide the version of Cosmic-Edit you're using?

This can be found on Pop!_OS, Ubuntu, and many other Debian derivatives by running the following in a terminal:

apt policy cosmic-edit

I just need the value next to Installed:

[flukejones]

@XV-02 I run fedora and install from git (just updated to today).

Details of my setup are:

Operating System: Fedora Linux 40
KDE Plasma Version: 6.0.0
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.8.0-0.rc6.49.fc40.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 20 × 13th Gen Intel® CoreT i7-13700H
Memory: 31.0 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: ROG Zephyrus M16 GU604VY_GU604VY_00130747B
System Version: 1.0

I run both KDE and Cosmic.

[flukejones]

Turned out I had a copy of cosmic-edit in my user bin dir, so i was never actually seeing updates when I rebuilt sysext.

[flukejones]

Re-opening as this is still true. Running bcc1ad8

[flukejones]

From what I can see the bad rendering is in set places (at default window size here)

[mmstick]

What graphics card and driver do you have? Does it look like this if you change the WGPU renderer, or disable GPU rendering by removing the wgpu feature from libcosmic?

[flukejones]

Hmm:

• __NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia WGPU_BACKEND=gl cosmic-edit
  This is nice and crisp, but on dgpu only
• WGPU_BACKEND=gl cosmic-edit draws blank squares
• RUST_LOG=info WGPU_BACKEND=vulkan WGPU_ADAPTER_NAME="GeForce" cosmic-edit is not selecting the nvidia like it should (tried a number of strings)

Using mesa 24.0.0 for Intel, 550.54.14 for nvidia. I'll try without wgpu feature if I have time.

[jackpot51]

The main reason for this is that the custom control cosmic-edit uses for text renders it to an image and the image size is calculated based on the logical size multiplied by the scale factor. When using a fractional size, that can sometimes end up being a size that doesn't exactly fit into integer logical pixels and then it scales incorrectly. I'm going to replace this workaround now that iced directly supports rendering cosmic_text buffers.

[flukejones]

Ah I see, that explains why resizing to a particular size helped.

[jackpot51]

This is partially improved by 2bfcfdf. It searches for a pixel size that is an integer in both the logical and physical coordinates. Unfortunately it does not work fully with the wgpu renderer. When I have more time I will switch to using a different rendering technique that will both improve performance and fix this issue when using the wgpu feature.