Update to bsnes v037r07? release.

New WIP.

The biggest news is that I've implemented what I was discussing
earlier, and it worked perfectly. The S-PPU enslavement to the S-CPU
is no more.

As of this point, all four processor cores, and all three of their
shared relationships, run completely independently of one another.

This required moving the inline timing code from the absolute most
timing-sensitive section of the emulator, to an entirely new external
class. It also required logging more state data, adding ~100k/second
more context switches, etc. It was unavoidable that the new approach
would be slower, but I was able to greatly mitigate the speed loss.
Right now, it stands at a ~6-8% speed loss from the previous release.

But there is good news:
1) aside from SuperFX / SA-1 support, which will require additional
processing inside the emulator core, no other changes should slow down
the emulator again. It can only get faster from here. Most
importantly, a range-based IRQ tester would offer a major speedup.
2) this approach will allow both a scanline-based and cycle-based
S-PPU core to work with only one S-CPU core. No need to subclass and
duplicate the timing code + scheduler as I was planning to before.
3) with this change, I was finally able to convert the scanline-based
S-PPU renderer to a hybrid that I've talked about with FitzRoy in the
past: this allowed me to finally cache OBSEL writes at (roughly) the
appropriate position, while still rendering the screen at a different
point. I render the screen at H=512, and cache OBSEL at H=1152. May
not be hardware accurate, but it allows Adv. of Dr. Franken + Winter
Olympics + Mega Lo Mania to all work as expected, all at the same
time.

It wasn't 100% exactly how I wanted to do things ... but I'm really
happy about this de-coupling. I've always been a purist when it comes
to implementing processor cores independently of one another, and it's
always bothered me greatly the way the CPU controlled the PPU and its
counters.

With the above changes, I've eliminated the four ppu.hack config
settings. I don't see much of a need for them.

I've also embedded the readme and license text files. FitzRoy, I
haven't had a chance to revise the readme as you were suggesting yet.
Not ignoring you there, it's just low on my priority list right now.

Lastly, I took FitzRoy's advice, and removed the WAV logger entirely.
I'm also going to leave the screenshot capture out. At least for now
... the UI is starting to get a bit too bloated for my tastes.

This is also the first uploaded WIP with the new debugging key-
bindings (tracing and memory export.) I don't expect anyone here to
have much use for them.

Anyway, testing would be appreciated. It's very likely that the OBSEL
cache position needs to be tweaked further. I recall LotR or something
also had issues with caching in the past ... but I couldn't find the
game at ::ahem:: the used game shop ... to test it.

I think there were other games that had different behavior based on
the old obsel_cache setting, too. Would be good to make sure they all
work as expected.

EDIT: Ah, "JRR Tolkein's LotR", bah. Yeah, no sprite flickering with
the new WIP. Also, speed hit only seems to affect Core 2's. No frame
drop on my Athlon. Probably something to do with locality of reference
or somesuch. Modern processors are too damned complicated :P

So then, assuming nobody spots any bugs ... how about a new release
tomorrow?

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This commit is contained in:
byuu
2008-12-14 05:31:00 +00:00
parent a721c7e91b
commit e370a35d7d
Update to bsnes v037r07? release.

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