Halftone revisit

I actually made this just to see if I could use fmod to make a tiling TexCoord, but using this is also a much more elegant solution than what I used in the previous post. It's probably a lot cheaper too.
(actually you can just use Frac instead, sort of forgot about that expression)

This has other uses too, for instance, if you packed textures into channels and need one clamped and one tiled, you can use this to tile a clamped texture.