Chart titles render as rectangles for non-Latin text

[Evan260]

Describe the bug
Chart titles fail to render Unicode text properly for many non-Latin texts, displaying rectangle placeholders (□□□□) instead of the actual characters. This affects Bengali, Hindi, Chinese, Japanese, Korean, Tamil, Telugu, Thai, Gujarati, Punjabi, and likely other languages / Unicode characters.

To Reproduce

1. Create a chart
2. Set the chart title to Bengali: বিক্রয় তথ্য চার্ট
3. Render the chart
4. Observe that title shows as □□□□□□□ instead of Bengali characters

Expected behavior
Chart titles should render Unicode text correctly, displaying the actual characters instead of rectangle placeholders.

Actual behavior
Non-Latin scripts render as rectangle placeholders (□□□□), indicating missing font support or text rendering issues.

Environment
OS: Windows 11
Framework: .NET 9
LiveCharts Version: 2.0.0-rc5.4
Platform: WinForms
Package: LiveChartsCore.SkiaSharpView.WinForms

Minimal Reproduction Code

csharpusing LiveChartsCore;
using LiveChartsCore.SkiaSharpView;
using LiveChartsCore.SkiaSharpView.WinForms;

var chart = new CartesianChart
{
    Title = new LabelVisual
    {
        Text = "বিক্রয় তথ্য চার্ট", // Bengali text - will show as rectangles
        TextSize = 24,
        Padding = new LiveChartsCore.Drawing.Padding(15)
    },
    Series = new ISeries[]
    {
        new LineSeries<double>
        {
            Values = new double[] { 10, 25, 15, 30, 20 }
        }
    }
};

Complete test case: Unicode Text Rendering Test

Impact
This significantly limits the international usability of LiveCharts2 for applications targeting:

• South Asian markets (Hindi, Bengali, Tamil, Telugu, Gujarati, Punjabi)
• East Asian markets (Chinese, Japanese, Korean)
• Southeast Asian markets (Thai)
• Middle Eastern markets (Arabic, Hebrew, Urdu)

Additional Context

• Other .NET WinForms text rendering (Labels, TextBoxes) works correctly with these scripts
• Issue specifically affects LiveCharts2 text rendering through SkiaSharp
• Similar font/Unicode issues also affect axis labels, legends, and tooltips

Related Issues: This may be related to broader SkiaSharp Unicode text rendering limitations or font configuration in the LiveChartsCore.SkiaSharp package.

EDIT:
I found a workaround.

Add this code in your application initialization:

/// <summary>
/// Configures LiveCharts font for proper Unicode text rendering, fixing the rendering of non-Latin languages.
/// </summary>
private static void SetLiveChartTitleFont()
{
    // I use "Segoe UI" for my app, but for some reason it doesn't work here. "Nirmala UI" seems to work for every language.
    LiveChartsCore.LiveCharts.Configure(config => config
        .AddSkiaSharp()
        .AddDefaultMappers()
        .HasGlobalSKTypeface(SKTypeface.FromFamilyName("Nirmala UI"))
    );
}

It works for most languages, but still not all.

[beto-rodriguez]

Hi

Currently you need to manually load the font for not-Latin based fonts, see the library installation instructions in the site, the good news is that to prevent this confusion, the library won't need this anymore since the next version of the library, labels will be smarter and much more performant.

[LeaFrock]

I’d like to know if the browser-side font issue can be resolved. Since rendering is currently handled by SkiaSharp, Blazor WASM can’t access the system fonts and falls back to the default “mono”. As a result, any non-Latin characters show up as empty squares.