Marginally better constants for ft_gray_for_premultiplied_srgb_bgra()
ft_gray_for_premultiplied_srgb_bgra()
in https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/src/base/ftbitmap.c#L478
https://accessibility.kde.org/hsl-adjusted.php is dead. Replacement link: http://www.brucelindbloom.com/index.html?WorkingSpaceInfo.html#SideNotes
Constants: 0.072186, 0.715158, 0.212656
Giving changed values at https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/src/base/ftbitmap.c#L491:
4731UL, 46869UL, 13937UL
I'm not using this function, so I don't mind if nobody else cares about it. Improvement is tiny at best.