Tiling an image

[yutannihilation]

Scene::fill() accepts peniko::BrushRef::Image as a brush, and I expect it fills the shape with repetition of the specified image if Extend::Repeated is specified. However, the following code doesn't fill. Is this the expected result? Is something wrong in my code?

    #[rustfmt::skip]
    let colors = [
        Color::RED,  Color::BLUE, Color::BLUE,
        Color::BLUE, Color::RED,  Color::BLUE,
        Color::BLUE, Color::BLUE, Color::RED,
    ];

    let mut blob: Vec<u8> = Vec::new();
    colors.iter().for_each(|c| {
        blob.push(c.r);
        blob.push(c.g);
        blob.push(c.b);
        blob.push(c.a);
    });

    let data = vello::peniko::Blob::new(Arc::new(blob));
    let image = vello::peniko::Image::new(data, vello::peniko::Format::Rgba8, 3, 3)
        .with_extend(vello::peniko::Extend::Repeat);
    let brush = vello::peniko::BrushRef::Image(&image);

    // Draw a filled circle
    let circle = Circle::new((400.0, 400.0), 200.0);
    scene.fill(
        vello::peniko::Fill::NonZero,
        Affine::IDENTITY,
        brush,
        None,
        &circle,
    );
    scene.stroke(
        &vello::kurbo::Stroke::new(10.0),
        Affine::IDENTITY,
        Color::WHITE,
        None,
        &circle,
    );

[DJMcNab]

This isn't yet implemented. See also discussion in #722 - we currently only properly support the Pad extend mode, and even then not properly. The code which would need to change would be in that same part of fine.

I don't think there's an existing issue for this, thanks for reporting.

[yutannihilation]

Oh, thanks for the explanation. I didn't catch up with the discussion in #722...!

[dfrg]

I have the code to get extend modes working in the fine shader but it’ll take more work to plumb it through the pipeline. I’d also like to support different extend modes for the x/y directions along with (at least) nearest neighbor sampling but those will require changes to peniko.

[marcpabst]

Just jumping in to say this is a super useful feature! It’d be awesome to see both better support for the current API and the addition of extend_x and extend_y.

[marcpabst]

@dfrg any chance you have a branch with the changes to the fine shader?