find when a word is within the current window

[Luca Ferrari]

Hi all,
I'm implementing a jump-to-label function that would split the current
window and scroll up/down within the same buffer to the point where a
label is defined. And it works! However, I'd like to have the split to
happen only when the label I'm searching for is not visible within the
current window (i.e., it makes sense to jump to it). How can I find if
a word is currently visible within the current window? I suspect,
since I already know at which line the label is, one way is to check
with window window boundaries against the label line number, but there
could be a smarter way.

Thanks,
Luca