Hi Kelvin If you only interested in subpixels shifts and intend to cache 3 positions, you can achieve using LCD rendering and https://freetype.org/freetype2/docs/reference/ft2-lcd_rendering.html#ft_library_setlcdgeometry. It is apparent that LCD rendering is essentially 3 traditional antialiased bitmaps produced for shifted outlines and stacked together. Therefore, you have it already for 1/3-pixel shifts by default. Because everything is periodic, you can continue with the LCD output and clever reading frame shifts for subpixel positioning too.
Theoretically, this should work. There is also https://freetype.org/freetype2/docs/reference/ft2-sizing_and_scaling.html#ft_set_transform . Perhaps you should wrap it into https://freetype.org/freetype2/docs/reference/ft2-cache_subsystem.html#ftc_face_requester. Alexei
