osu!mania key images leave tiny gaps between columns about osu

[frenzibyte]

Please attach your skin.

[Saerdna123]

o2def2 (Saerdna).zip
here is my skin

[frenzibyte]

Isolated to a framework-level issue:

(white-texture.png is literally just a 512x512 block of white pixels).

code

// Copyright (c) ppy Pty Ltd <[email protected]>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using NUnit.Framework;
using osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Graphics.Textures;
using osuTK;

namespace osu.Framework.Tests.Visual.Containers
{
    public partial class TestSceneSpriteLayout : FrameworkTestScene
    {
        [Resolved]
        private TextureStore textures { get; set; } = null!;

        [Test]
        public void TestFillFlowContainer()
        {
            AddStep("add", () => Child = new FillFlowContainer
            {
                Anchor = Anchor.Centre,
                Origin = Anchor.Centre,
                AutoSizeAxes = Axes.Both,
                Direction = FillDirection.Horizontal,
                Scale = new Vector2(2f),
                Children = new[]
                {
                    new Sprite
                    {
                        Texture = textures.Get("white-texture.png"),
                    },
                    new Sprite
                    {
                        Texture = textures.Get("white-texture.png"),
                    },
                }
            });
        }
    }
}

Interestingly, this only happens with image-backed Sprites. It cannot be reproduced with Box sprites, or generally the white-pixel texture.

[frenzibyte]

After a period of investigation, it appears that the gaps are caused by the texture shader sampling beyond the texture's bounds, leaving a black/gray pixel between keys. Using WrapMode.ClampToEdge works around the issue.