Inter Variable rendering incorrectly

[sowa705]

Hi, i'm trying to render text with the https://rsms.me/inter/ font but the result is not correct.

var fontFamily = fontCollection.Get("Inter Variable");
var font = fontFamily.CreateFont(96, FontStyle.Regular);

var img = new Image<Rgba32>(1960, 180, Rgba32.ParseHex("#FF0000FF"));
img.Mutate(g => {
    var textFont = font;
    var paths = TextBuilder.GenerateGlyphs("Inter variable", new TextOptions(textFont) {
        Origin = new Vector2(980, 90),
        VerticalAlignment = VerticalAlignment.Center,
        HorizontalAlignment = HorizontalAlignment.Center,
        TextAlignment = TextAlignment.Center,
        Font = textFont
    });
    g.Fill(Color.Black, paths);
});

img.Save("test.png");

Resulting image

Test environment

SixLabors.Fonts Version="2.0.1"
SixLabors.ImageSharp Version="3.1.1"
SixLabors.ImageSharp.Drawing Version="2.1.0"
OS: Windows 11 x64
Runtime: .NET 8.0.100

[JimBobSquarePants]

Sorry, I thought this was asking for support for the variable output. (I couldn’t see the detail on my phone)

If you use DrawText. It will render properly. There’s something not working with filling path generation for certain glyphs. @tocsoft would you have a clue why this would happen given it should be the same vectors?

[tocsoft]

I don't think that's a bug, the issue is that fonts expect to be rendered with the NoneZero Intersection Rule (which our drawText apis do for you) but the Fill api defaults to the EvenOdd Intersection Rule rule for rasterization.

[tocsoft]

FYI the DrawText APIs will be more efficient (at least for larger pieces text) you should generally only use the TextBuilder.GenerateGlyphs() path building base APIs if you need to transform/mutate vectors themselves.

[JimBobSquarePants]

Thanks @tocsoft !

[sowa705]

Thanks for help and explanation

[SpaceCheetah]

Is there a way to detect when a font needs NonZero or not, without visually looking at it? Surely there is somewhere, but I'm not seeing where DrawText deals with that (and for my situation I need transformations at the glyph level).

[SpaceCheetah]

On closer inspection, it looks like buried deep in RichTextGlyphRenderer it always uses NonZero, unless I'm reading something wrong. Is that just always correct?

[JimBobSquarePants]

Yeah TrueType and CFF fonts always use NonZero