Improve text rendering clarity in Avalonia UI compared to previous WPF frontend

[michael-damatov]

Description

After the migration from the WPF frontend to Avalonia in ILSpy 11, text appears noticeably less sharp on my system compared to previous ILSpy versions.

This is not a syntax-highlighting or color-contrast issue. The concern is the actual text rendering quality, which appears softer/blurrier than the WPF-based releases.

Environment

• ILSpy version: 11.0.0.9375+cdeae656fee6e184ff76cdc549edc7f9031dba09
• OS: Windows 11 25H2
• Monitor 1
  • Display resolution: 5120 x 1440
  • Windows scaling: 100%
• Monitor 2
  • Display resolution: 3654 x 2160
  • Windows scaling: 200%

Observed Behavior

• Decompiled code text appears less crisp than in ILSpy 10.x.
• Tree view and UI text may also appear softer.
• The effect is most noticeable during extended reading sessions.

Expected Behavior

Text rendering should be as sharp and readable as possible, ideally matching the clarity previously achieved by the WPF frontend.

Additional Information

The issue may be related to differences between WPF's ClearType-based text rendering and Avalonia's rendering pipeline.

Potential areas worth investigating:

• Text hinting configuration
• Pixel snapping/layout rounding
• Fractional scaling behavior
• Font rendering settings
• Avalonia rendering backend options

Comparison

A side-by-side comparison between:

• ILSpy 11.x (Avalonia)
  

• ILSpy 10.x (WPF)
  

on the same machine shows a visible difference in text clarity.

[christophwille]

Might that be font-specific? I am on Windows, use Consolas, and have no issues:

[siegfriedpammer]

The font you are using in WPF is definitely Consolas, while the one shown in the Avalonia screenshot looks nothing like it. Or maybe it's a different "style" like "Consolas Light" (no idea, if that even exists). Could also be that it's a non-standard/sub-point font size?

From your screenshots (Avalonia):

And WPF:

You can definitely see that it's not the same font: especially noticable when comparing the shape of S, p and y.

[christophwille]

Try Consolas 14pt. I'd be interested if that looks ok on your machine.

[michael-damatov]

"Consolas" looks slightly better. However, it doesn't support ligatures, so I use "JetBrains Mono". In any case, the tree view isn't as crisp as in the version 10.

ILSpy 11 with Consolas 14

ILSpy 10 with Consolas 9.5 (comparable font size)

ILSpy 11 with JetBrains Mono 14

ILSpy 10 with JetBrains Mono 10 (comparable font size)

[christophwille]

So it is less about the decompiled text view but menus / tree ("system font")?

Edit: Additionally, are the screenshots from 100% or 200% monitor?

[michael-damatov]

Both, actually: the decompiled text view as well as the menus/tree.

The screenshots are from the 100% monitor (the scaled rendering on the 200% monitor looks flawless).

[christophwille]

One more question: did you modify Accessibility > Text size? In #3987 I started experimenting with following that setting (because I myself have that set).

Binaries via https://github.com/icsharpcode/ILSpy/actions/workflows/build-ilspy.yml?query=branch%3Awin-a11y-textsize

[michael-damatov]

I didn't change the Accessibility > Text size.