I don't claim to know much of anything about programming shaders. But, this seems more like a matter of resolution to be able to emulate the subtle effects of a CRT, at least to down to the masking and such. We are getting into an era of some pretty high pixel densities. Hopefully, that will translate into monitors and TVs (and projectors). A 4k monitor/TV might be on the cusp of being able to do this sort of emulation...?