Default value for “onscreen” = false.
1 - If top of char and bottom of char are equal (so both on screen, or both not on screen) do 2, else out whatever “onscreen” was already set to.
2 - if top of char is different from whatever “onscreen” was already set to, then set value of “onscreen” to the same as itself, else out whatever “onscreen” was already set to.
how is this complicated? 
I mean it already works. I was just wondering if it could be even simpler, like without those branches.
I don’t need to reset the value, just update whenever it changes