Blaster Master Area 5 Boss AI

<uraniumanchor> All this time I figured the area 5 boss's pausing was based on the RNG seed... I mean it is, just not in the way that I thought
<uraniumanchor> I figured he read it as a timer to determine how long to hold still, but that's definitely NOT what he's doing
<uraniumanchor> Time to dig into this a bit more
<uraniumanchor> Yeah the problem is even if we know how he reads the RNG, manipulating the RNG is all but impossible
<uraniumanchor> Beacuse all of the gumdrop robots tweak the RNG a *lot*
<uraniumanchor> They read it like 4 times ta second to determine whether or not to shoot
<uraniumanchor> At best you could maybe watch for a certain shot pattern
<uraniumanchor> Ok so what I'm seeing now
<uraniumanchor> When he's holding still
<uraniumanchor> He hold still for 32 frames
<uraniumanchor> Then he has a... 3 out of 16 chance to not move for another 32 frames
<uraniumanchor> Actually wait maybe not
<uraniumanchor> Looks like he also has a chance to wait for 16 frames
<uraniumanchor> Ok, he DOES use the RNG value to determine how far to walk, with a range of 32 to 160 frames, in increments of 16
<shiningdragoon> hahahaha freaking crab
<shiningdragoon> why do you need to be so complicated
<uraniumanchor> With a 50/50 chance of going left or right
<uraniumanchor> When he starts walking
<mattrick_> crab for biggest a-hole game boss ever
<uraniumanchor> holy god this code
<mattrick_> ever since i was a kid i have HATED that thing
<uraniumanchor> He reads the RNG in so many different ways I'm having trouble following all of it
<uraniumanchor> It looks like he has several different states though, trying to see if I can figure out what each of them means
<shiningdragoon> so basically the programmer had a lot of fun on that boss
<uraniumanchor> Yeah he's basically doing an RNG poke at every state transition to determine what to do next
<uraniumanchor> And every state he's in, is some multiple of 16, with minimums and maximums
<uraniumanchor> ok so from what I'm seeing when I watch the memory values as well as trying to understand this code, when he pauses, it's always for 32 frames, but he has a small chance to pause again instead of moving
<uraniumanchor> And when he moves it's for anywhere from 32 to 144 frames in 16 frame intervals
<uraniumanchor> There seems to be some other stuff going on here too but I can't make sense of it
<uraniumanchor> So actually in theory it's possible to completely lock him into place
<uraniumanchor> By manipulating the RNG so that he never moves
<uraniumanchor> But since the TAS just glitches him out and that's the only way you'd realistically accomplish that, I wouldn't consider that useful
<shiningdragoon> lol the tas boss fight is hilarious
<shiningdragoon> abuses the fk out of grenades
<mattrick_> blaster master is a cruel mistress
<mattrick_> when she loves you
<mattrick_> its great
<mattrick_> when she hates you, you will SUFFER
<the_greenleaf_effect> @Mattrick_ makes a valid point
<uraniumanchor> Well even though I didn't discover any magic bullet, I have a greater understanding of how that boss works now
<uraniumanchor> So that makes me feel better :P
<uraniumanchor> Huh, there's some dead code in his subroutines it looks like
<uraniumanchor> HE's got a couple of bits of code that don't have any branches to them anywhere
<shiningdragoon> he was also supposed to spit fire
<shiningdragoon> but the devs said no
<uraniumanchor> hahah
<uraniumanchor> I was thinking maybe it had something to do with his bubbles, but his bubbles don't use the RNG whatsoever
<uraniumanchor> Bubbles are completely fixed
<uraniumanchor> hahah what the fuck
<uraniumanchor> So I'm messing with memory values trying to see if I Can figure out what the bosses various states are
<uraniumanchor> I set his little "am I moving or not" flag to a particular value and now not only is he not moving at all but his bubble patterns are completely wonky
<shiningdragoon> anyway to ever adjust that value in game?
<uraniumanchor> shining there IS a bit of code that sets his flag to that value, but I don't see any branches to it
<uraniumanchor> So I don't think there's a way to reach it in practice
<uraniumanchor> Dead code probably, there's definitely quite a bit of that in the cart
<uraniumanchor> If we could but figure out a way to have the CPU jump to address $A73F it would lock up the boss and we'd be home free :P
<shiningdragoon> might as well just credit warp (please never)
<uraniumanchor> hahah fuck that
<uraniumanchor> we'd make a new category for sure
<uraniumanchor> Also, boss has 128 hp, and he changes bubble patterns at 64 and 32 hp