[Uno WASM] Setting font crashes runtime

[mikernet]

Describe the bug
Changing the font from the default crashes the runtime when a chart is first drawn.

To Reproduce
Using:

    private static async Task<SKTypeface> LoadTypefaceFromApplicationUriAsync(Uri uri)
    {
        var file = await StorageFile.GetFileFromApplicationUriAsync(uri);
        var stream = await file.OpenStreamForReadAsync();
        return SKTypeface.FromStream(stream);
    }

    // App.xaml.cs OnLauched()

    var fontUri = new Uri(RootFrame.FontFamily.Source, UriKind.Absolute);
    DefaultSKTypeface = await LoadTypefaceFromApplicationUriAsync(fontUri);

The above code successfully loads the Open Sans font that is the default on Uno WASM into DefaultSKTypeface, but if it is used anywhere in LiveCharts, such as setting it on an axis label or setting it globally like:

    LiveCharts.Configure(config => {
        config.HasGlobalSKTypeface(DefaultSKTypeface);
    });

Then the runtime crashes as per above as soon as a page with a chart is shown. The code above works fine on WinUI and Desktop targets. Commenting out the line that sets the typeface stops the app from crashing and showing any of the errors indicated above in the console.

Expected behavior
A clear and concise description of what you expected to happen.

Desktop (please complete the following information):

• OS: Windows 11
• Browser: Edge

Additional context
Tested with both rc4.5 and rc5.1.

[mikernet]

I also tried embedding the Arial font into the project and using that with the same result.

[mikernet]

Doing config.HasGlobalSKTypeface(SKTypeface.Default); (which sets it to Noto Mono) also causes it to crash.

[mikernet]

The problem is here:

LiveCharts2/src/skiasharp/LiveChartsCore.SkiaSharp/Drawing/Geometries/LabelGeometry.cs

Line 72 in fc8320b

var shaper = paint.Typeface is not null ? new SKShaper(paint.Typeface) : null;

It crashes when it tries to load the harfbuzz library to create the SKShaper. Not sure what the fix is though.

[mikernet]

Adding this to the project fixed the issue:

  <ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'browserwasm'">
    <PackageReference Include="HarfBuzzSharp.NativeAssets.WebAssembly" Version="7.3.0.3" />
  </ItemGroup>

Out of curiosity - why does it need the shaper only for non-default fonts?