Missing colour support in Font atlases

[EVAST9919]

Currently any colour in font atlas will become white. Atlas example: Result:

[bdach]

Maybe what is really needed here is a way to achieve the same visual effect (so e.g. vertical gradient & shadow on text) without resorting to using bitmaps raw. It might even be possible to set gradient colour on text already? Not sure.

[EVAST9919]

Gradient is possible, yes. For this particular example the main problem is outline. Though it can be recreated using BufferedContainer, however there's a big performance hit once this container is being scaled (I mean transforms). Yes, you can use RedrawOnScale = false, but then visuals will suffer.

[bdach]

Ah right, I missed the outline due to dark theme. That does seem to be a bit of a problem...

Maybe this should exist alongside SpriteText as a RawSpriteText or similar and make that use source colour? Not sure.

[EVAST9919]

Can you please tell what should I change (if it's a simple one) so at very least I can use local framework? I can't really find the point where the colour is specified.

[peppy]

You have two options:

• Change RawCachingGlyphStore to save and read RGBA instead of A

https://github.com/ppy/osu-framework/blob/2b1dd17b9caae24d38a0075adad5db1b6c3759d3/osu.Framework/IO/Stores/RawCachingGlyphStore.cs#L77-L78

and

https://github.com/ppy/osu-framework/blob/2b1dd17b9caae24d38a0075adad5db1b6c3759d3/osu.Framework/IO/Stores/RawCachingGlyphStore.cs#L119-L126

• Use TimedExpiryGlyphStore

            Fonts.AddStore(new TimedExpiryGlyphStore(Resources, "font"));

Note that the second will take a touch longer to load (and will have a temporarily higher memory footprint) as it is no longer benefitting from caching the PNG content to disk. You'd probably want to only use this for the fonts you need to. But you can also use it without a local framework fork.

[smoogipoo]

If you want to fix it, you have to know that RawCachingGlyphStore caches the glyph pages as alpha maps.

The createCachedPageInfo() method creates the alpha map, specifically through the following code: https://github.com/ppy/osu-framework/blob/eca80e83b118de60b745300791ce3b448ab7985c/osu.Framework/IO/Stores/RawCachingGlyphStore.cs#L71-L95

The createTextureUpload() method reads the alpha map, and creates the resulting per-character texture upload.

[EVAST9919]

Thanks!