* Ranges between full brightness to half-brightness (50% of fullbright effect).
* Has both software and GL support (I think - GL needs to be doublechecked, but I think it's just GL being murky in general).
* Used by Rings.
* Backport FF_GLOBALANIM and FF_RANDOMANIM extensions to FF_ANIMATE from 2.2.
* Rings use the former instead of their own hacky solution to the problem.
* Also backport FF_VERTICALFLIP, because why not.
* Inverts sprite relative to gravity. I remember wanting this for the flipped death sprite for Jawz, but then Oni drew his own frame for that, so it doesn't matter.
* Refactor vissprite struct a tad, given I did so in internal where I pulled most of these improvements from.
* Should be no in-game affect; let me know if you notice any regressions.
* Speaking of, actively enforced not being able to be Super and NiGHTS at the same time.
* Also on that note - SPR2_TRNS is now the NiGHTS transformation. The Super transformation is (FF_SPR2SUPER|SPR2_TRNS).
* SPR2_NPAN is now SPR2_NSTN, since it matches Super Sonic's stun animation rather than the pain animation.
* Fixed a bunch of things where Super float was handled badly with 2AM brain.
* Fixed the R_ProjectSprite error going out of spr2names' bounds.
* Fixed order of FF's in dehackéd.
* Fixed that thing where Super Sonic was blue for 1 tic after transformation, and the life icon was a blue Super Sonic.
* Super sprites are now deliniated via an additional S_SUPER lump between S_START and S_END. Above are normal sprites, below are super sprites. Handled internally via FF_SPR2SUPER.
* Sprite2 numbers are now appropriately limited for the data type that stores them.
* SPR2_SPIN is now SPR2_ROLL, SPR2_DASH is now SPR2_SPIN and SPR2_PEEL is now SPR2_DASH. Makes more sense, right?
* flips the sprite ala MFE_VERTICALFLIP except you don't need to flip the direction of gravity for the object just to draw upside down
* stacks properly with reverse gravity
* FF_MIDDLESTARTCHANCE - has a 50% chance of starting the spr2 or FF_ANIMATE animation halfway in
* FF_SPR2ENDSTATE - if var1 == S_NULL, don't loop, just stop incrementing the frames. Otherwise, go to the state represented by var1.
The former is just something I did for fun, the latter is something that'll come in handy when porting in new-character-moves.
