CanvasDrawingSession.DrawGlyphRun renders emojis in monochrome when using color font and CanvasDrawTextOptions.EnableColorFont option

[MaxWellHays]

I am currently working on a UWP application that requires custom text layouting logic. I have been experimenting with the CanvasDrawingSession.DrawGlyphRun method in Win2D to achieve this, as it provides more control over glyph positioning compared to the previous method I was using, CanvasDrawingSession.DrawTextLayout. However, I have encountered an issue where color emojis are not being rendered in color when using DrawGlyphRun.

To provide some context, I was previously using multiple instances of CanvasTextLayout with DrawTextLayout, but due to new requirements, I need more control over glyphs position. While I was able to convert all existing functionality from DrawTextLayout to DrawGlyphRun, the issue with color emoji rendering remains.

As a workaround, I am considering using DrawText in places where I need to render color emojis, but I would like to know if there is a better way to handle this or if I am missing something. Additionally, I am also considering implementing this logic directly in C++ like in the DWriteColorGlyph sample.

Below is a basic control implementation which renders text using all 3 available methods and shows that emoji rendered using DrawGlyphRun is shown in monochrome:

public sealed partial class BasicDrawGlyphRunControl : UserControl
{
    private const string Text = "😀";
    private readonly CanvasGlyph[] _glyphs;
    private readonly IReadOnlyList<KeyValuePair<CanvasCharacterRange, CanvasScaledFont>> _font;
    private readonly CanvasTextFormat _textFormat = new()
    {
        FontSize = 36,
        Options = CanvasDrawTextOptions.EnableColorFont,
    };
    private CanvasSolidColorBrush? _textBrush;

    public BasicDrawGlyphRunControl()
    {
        DataContext = this;
        InitializeComponent();

        var textAnalyzer = new CanvasTextAnalyzer(Text, CanvasTextDirection.LeftToRightThenTopToBottom);

        _font = textAnalyzer.GetFonts(_textFormat);
        var scripts = textAnalyzer.GetScript();
        _glyphs = textAnalyzer.GetGlyphs(_font[0].Key, _font[0].Value.FontFace, _textFormat.FontSize, isSideways: false, isRightToLeft: false, scripts[0].Value);
    }

    private void OnCanvasDraw(CanvasControl sender, CanvasDrawEventArgs args)
    {
        _textBrush ??= new CanvasSolidColorBrush(sender, Colors.Black);

        // DrawText
        args.DrawingSession.DrawText(Text, new Vector2(0, 0), _textBrush, _textFormat);

        // DrawTextLayout
        var textLayout = new CanvasTextLayout(sender, Text, _textFormat, float.PositiveInfinity, float.PositiveInfinity)
            {
                Options = CanvasDrawTextOptions.EnableColorFont,
            };
        args.DrawingSession.DrawTextLayout(textLayout, new Vector2(50, 0), _textBrush);

        // DrawGlyphRun
        var fontFace = _font[0].Value.FontFace;
        var position = new Vector2(100, (fontFace.Ascent + fontFace.LineGap) * _textFormat.FontSize);
        args.DrawingSession.DrawGlyphRun(position, fontFace, _textFormat!.FontSize, _glyphs!, false, 0, _textBrush);
    }
}

Here is a screenshot of result control:

[lgBlog]

private readonly CanvasTextFormat _textFormat = new()
{
FontSize = 36,
};

This property is assigned outside.
_textFormat.Options = CanvasDrawTextOptions.EnableColorFont;

[MaxWellHays]

private readonly CanvasTextFormat _textFormat = new() { FontSize = 36, };

This property is assigned outside. _textFormat.Options = CanvasDrawTextOptions.EnableColorFont;

This change doesn't fix the issue, unfortunatelly, the emoji is still rendered in monochrome for DrawGlyphRun.
Here is my modified sample.