Removing joystick ball support
Trackball support just gotta go y'all. :D
For a start, no-one making a game for 99.999999% of the PC game playing population will rely on it for input, because no-one else has a game controller which has a supported trackball, and that number maaay need more nines. :P
So it's basically intended for installations or personal prototypes, right?
Just imagine if it was requested that LÖVE support another piece of hardware which is as uncommon as game controllers with trackballs. The reaction would probably be "uh... you might want to compile that in yourself". So, I think it should be the same; if the need for having trackball support ever arises, whoever wants to use it can compile their own LÖVE build.
It might be tempting to say "but it's already there, and there's no reason not to have it, right?". I'd suggest that there is in fact a real cost to having it there. For a start, everyone who looks deeply enough into the API functionality will see it, wonder what it's about, maybe read about it, maybe try to understand it. And this adds up!
I'm reminded of this blog post at Programming in the 21st Century about vertical tabs: http://prog21.dadgum.com/76.html
Even the fact that some person is pressing keys on a keyboard to type this is because of
love.joystick.getBallCount, when I should be breaking out fresh/questionable dance moves instead.
On a related note, if anyone wants to add robot suit support to LÖVE, this is completely okay with me.