> Example of who did: Metro apps in Windows 8 no longer use ClearType (RGB subpixel rendering), but plain greyscale antialiasing.
That's a victim of mobile-optimized toolkits. RGB subpixel rendering doesn't work on GPU-accelerated UIs that are on devices that are rotated. As in, it's expected to have the subpixel ordering change semi-frequently, and that change needs to happen as fast as possible. Since all the text is cached in GPU textures, that would require tearing down the font caches and re-building them every time the user rotates. That's prohibitively expensive, which means no RGB-subpixel rendering.
On mobile devices this hasn't been an issue because raw density saves the day. Your average phone's pixels are smaller than your typical desktop/laptop's subpixels. Maybe some day desktop/laptop will get a density boost, maybe...
Subpixel smoothing requires vector outlines to get good results, so scaling a bitmap won't work in practice. More importantly, font rendering is optimised to a specific size, i.e. the bitmap for 32x32 isn't just a scaled version of the 16x16 bitmap. The usual mechanism for this is hinting, but some engines use their own heuristics (e.g. CoreText, and maybe Metro?).
That's a victim of mobile-optimized toolkits. RGB subpixel rendering doesn't work on GPU-accelerated UIs that are on devices that are rotated. As in, it's expected to have the subpixel ordering change semi-frequently, and that change needs to happen as fast as possible. Since all the text is cached in GPU textures, that would require tearing down the font caches and re-building them every time the user rotates. That's prohibitively expensive, which means no RGB-subpixel rendering.
On mobile devices this hasn't been an issue because raw density saves the day. Your average phone's pixels are smaller than your typical desktop/laptop's subpixels. Maybe some day desktop/laptop will get a density boost, maybe...