Not so much hard but a hack. There is also no clear non-hackish way to implement sub-pixel rendering after 20 years of experience across at least three platform

Not so much hard but a hack. There is also no clear non-hackish way to implement sub-pixel rendering after 20 years of experience across at least three platforms. Also since we no longer have consistent sub-pixel layouts, sub-pixel rendered text is no longer portable to another screen, such as you get with an image containing text on a web page.