mirror of https://github.com/bsnes-emu/bsnes.git
5 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Tim Allen
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bf70044edc |
Update to v102r05 release.
byuu says:
Changelog:
- higan: added Makefile option,
`build=(release|debug|instrument|optimize)` , defaults to release
- PCE: added preliminary PSG (sound) emulation
The Makefile thing is just to make it easier to build debug releases
without having to hand-edit the Makefile. Just say "gmake build=debug"
and you'll get -g, otherwise you'll get -O3 -s. I'll probably start
adding these build= blocks to my other projects. Or maybe I'll put it
into nall, in which case release will need a different name ... a stable
-01, and a fast -03 mode. I also want to add a mode to generate
profiling information (via gprof.)
Unfortunately, the existing documentation on the PCE's PSG is as
barebones as humanly possible.
Right now, I support waveform mode, direct D/A mode, and noise
generation mode. However for noise, I'm not actually generating a proper
square wave, and I don't know the PRNG algorithm used for choosing the
random values. So for now, I'm just feeding in nall::random() values to
it.
I'm also not sure about the noise mode's frequency counter. Magic Kit is
implying it's 64*~frequency, but that results in an 11-bit period. It
seems only logical that we'd want a 12-bit period. So my guess is that
it's actually 12-bit, and halfway through it alternates between two
randomly generated values every 32 samples, and the two values are
generated every time the period hits zero.
Next up, it's not clear when the period counter is reloaded, either for
the waveform or the noise mode. So for now, when enabling the channel, I
reload the waveform period. And when enabling noise mode, I reload the
noise period. I don't know if you need to do it when writing to the
frequency registers or not.
Next, it's not clear whether the period is a decrement-and-compare, or a
compare-and-decrement, and whether we reload with frequency,
frequency-1, or frequency+1. There's this cryptic note in
pcetext.txt:
> The PSG channel frequency is 12 bits, $001 is the highest frequency,
> $FFF is the next to lowest frequency, and $000 is the lowest frequency.
As best I can tell, he's trying to say that it's decrement-and-compare.
Whatever the case, there's periodic popping noises every few seconds. I
thought it might be because this is the first system with a fractional
sampling rate (~3.57MHz), but rounding the frequency to a whole number
doesn't help at all, and emulator/audio should be able to handle
fractional resampling rates anyway.
The popping noises could also be due to PSG writes being cycle-timed,
and my HuC6280 cycle timings not being very great yet. The PSG has no
kind of interrupts, so I think careful timing is the only way to do
certain things, especially D/A mode.
Next up, I really don't understand the frequency modulation mode at all.
I don't have any idea whatsoever how to support that. It also has a
frequency value that we'll need to understand how the period works and
reloads. Basic idea though is the channel 1 output turns into a value to
modulate channel 0's frequency by, and channel 1's output gets muted.
Next up, I don't know how the volume controls work at all. There's a
master volume left+right, per-channel volume left+right, and per-channel
overall volume. The documentation lists their effects in terms of
decibels. I have no fucking clue how to turn decibels into multiply-by
values. Let alone how to stack THREE levels of audio volume controls
>_>
Next, it looks like the output is always 5-bit unsigned per-channel, but
there's also all the volume adjustments. So I don't know the final
bit-depth of the final output to normalize the value into a signed
floating point value between -1.0 and +1.0. So for now, half the
potential speaker range (anything below zero) isn't used in the
generated output.
As bad as all this sounds, and it is indeed bad ... the audio's about
~75% correct, so you can definitely play games like this, it just won't
be all that much fun.
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Tim Allen
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ee7662a8be |
Update to v102r04 release.
byuu says:
Changelog:
- Super Game Boy support is functional once again
- new GameBoy::SuperGameBoyInterface class
- system.(dmg,cgb,sgb) is now Model::(Super)GameBoy(Color) ala the PC
Engine
- merged WonderSwanInterface, WonderSwanColorInterface shared
functions to WonderSwan::Interface
- merged GameBoyInterface, GameBoyColorInterface shared functions to
GameBoy::Interface
- Interface::unload() now calls Interface::save() for Master System,
Game Gear, Mega Drive, PC Engine, SuperGrafx
- PCE: emulated PCE-CD backup RAM; stored per-game as save.ram (2KiB
file)
- this means you can now save your progress in games like Neutopia
- the PCE-CD I/O registers like BRAM write protect are not
emulated yet
- PCE: IRQ sources now hold the IRQ line state, instead of the CPU
holding it
- this fixes most SuperGrafx games, which were fighting over the
VDC IRQ line previously
- PCE: CPU I/O $14xx should return the pending IRQ bits even if IRQs
are disabled
- PCE: VCE and the VDCs now synchronize to each other; fixes pixel
widths in all games
- PCE: greatly increased the accuracy of the VPC priority selection
code (windows may be buggy still)
- HuC6280: PLA, PLX, PLY should set Z, N flags; fixes many game bugs
[Jonas Quinn]
The big thing I wanted to do was enslave the VDC(s) to the VCE. But
unfortunately, I forgot about the asynchronous DMA channels that each
VDC supports, so this isn't going to be possible I'm afraid.
In the most demanding case, Daimakaimura in-game, we're looking at 85fps
on my Xeon E3 1276v3. So ... not great, and we don't even have sound
connected yet.
We are going to have to profile and optimize this code once sound
emulation and save states are in.
Basically, think of it like this: the VCE, VDC0, and VDC1 all have the
same overhead, scheduling wise (which is the bulk of the performance
loss) as the dot-renderer for the SNES core. So it's like there's three
bsnes-accuracy PPU threads running just for video.
-----
Oh, just a fair warning ... the hooks for the SGB are a work in
progress.
If anyone is working on higan or a fork and want to do something similar
to it, don't use it as a template, at least not yet.
Right now, higan looks like this:
- Emulator::Video handles the platform→videoRefresh calls
- Emulator::Audio handles the platform→audioSample calls
- each core hard-codes the platform→inputPoll, inputRumble calls
- each core hard-codes calls to path, open, load to process files
- dipSettings and notify are specialty hacks, neither are even hooked
up right now to anything
With the SGB, it's an emulation core inside an emulation core, so
ideally you want to hook all of those functions. Emulator::Video and
Emulator::Audio aren't really abstractions over that, as the GB core
calls them and we have to special case not calling them in SGB mode.
The path, open, load can be implemented without hooks, thanks to the UI
only using one instance of Emulator::Platform for all cores. All we have
to do is override the folder path ID for the "Game Boy.sys" folder, so
that it picks "Super Game Boy.sfc/" and loads its boot ROM instead.
That's just a simple argument to GameBoy::System::load() and we're done.
dipSettings, notify and inputRumble don't matter. But we do also have to
hook inputPoll as well.
The nice idea would be for SuperFamicom::ICD2 to inherit from
Emulator::Platform and provide the desired functions that we need to
overload. After that, we'd just need the GB core to keep an abstraction
over the global Emulator::platform\* handle, to select between the UI
version and the SFC::ICD2 version.
However ... that doesn't work because of Emulator::Video and
Emulator::Audio. They would also have to gain an abstraction over
Emulator::platform\*, and even worse ... you'd have to constantly swap
between the two so that the SFC core uses the UI, and the GB core uses
the ICD2.
And so, for right now, I'm checking Model::SuperGameBoy() -> bool
everywhere, and choosing between the UI and ICD2 targets that way. And
as such, the ICD2 doesn't really need Emulator::Platform inheritance,
although it certainly could do that and just use the functions it needs.
But the SGB is even weirder, because we need additional new signals
beyond just Emulator::Platform, like joypWrite(), etc.
I'd also like to work on the Emulator::Stream for the SGB core. I don't
see why we can't have the GB core create its own stream, and let the
ICD2 just use that instead. We just have to be careful about the ICD2's
CPU soft reset function, to make sure the GB core's Stream object
remains valid. What I think that needs is a way to release an
Emulator::Stream individually, rather than calling
Emulator::Audio::reset() to do it. They are shared\_pointer objects, so
I think if I added a destructor function to remove it from
Emulator::Audio::streams, then that should work.
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Tim Allen
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186f008574 |
Update to v102r03 release.
byuu says: Changelog: - PCE: split VCE from VDC - HuC6280: changed bus from (uint21 addr) to (uint8 bank, uint13 addr) - added SuperGrafx emulation (adds secondary VDC, plus new VPC) The VDC now has no concept of the actual display raster timing, and instead is driven by Vpulse (start of frame) and Hpulse (start of scanline) signals from the VCE. One still can't render the start of the next scanline onto the current scanline through overly aggressive timings, but it shouldn't be too much more difficult to allow that to occur now. This process incurs quite a major speed hit, so low-end systems with Atom CPUs can't run things at 60fps anymore. The timing needs a lot of work. The pixels end up very jagged if the VCE doesn't output batches of 2-4 pixels at a time. But this should not be a requirement at all, so I'm not sure what's going wrong there. Yo, Bro and the 512-width mode of TV Sports Basketball is now broken as a result of these changes, and I'm not sure why. To load SuperGrafx games, you're going to have to change the .pce extensions to .sg or .sgx. Or you can manually move the games from the PC Engine folder to the SuperGrafx folder and change the game folder extensions. I have no way to tell the games apart. Mednafen uses CRC32 comparisons, and I may consider that since there's only five games, but I'm not sure yet. The only SuperGrafx game that's playable right now is Aldynes. And the priorities are all screwed up. I don't understand how the windows or the priorities work at all from sgxtech.txt, so ... yeah. It's pretty broken, but it's a start. I could really use some help with this, as I'm very lost right now with rendering :/ ----- Note that the SuperGrafx is technically its own system, it's not an add-on. As such, I'm giving it a separate .sys folder, and a separate library. There's debate over how to name this thing. "SuperGrafx" appears more popular than "Super Grafx". And you might also call it the "PC Engine SuperGrafx", but I decided to leave off the prefix so it appears more distinct. |
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Tim Allen
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c40e9754bc |
Update to v102r01 release.
byuu says:
Changelog:
- MS, MD, PCE: remove controllers from scheduler in destructor
[hex_usr]
- PCE: no controller should return all bits set (still causing errant
key presses when swapping gamepads)
- PCE: emulate MDR for hardware I/O $0800-$17ff
- PCE: change video resolution to 1140x242
- PCE: added tertiary background Vscroll register (secondary cache)
- PCE: create classes out of VDC VRAM, SATB, CRAM for cleaner access
and I/O registers
- PCE: high bits of CRAM read should be set
- PCE: partially emulated VCE display registers: color frequency, HDS,
HDW, VDS, VDW
- PCE: 32-width sprites now split to two 16-width sprites to handle
overflow properly
- PCE: hopefully emulated sprite zero hit correctly (it's not well
documented, and not often used)
- PCE: trigger line coincidence interrupts during the previous
scanline's Hblank period
- tomoko: raise viewport from 320x240 to 326x242 to accommodate PC
Engine's max resolution
- nall: workaround for Clang compilation bug that can't figure out
that a char is an integral data type
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Tim Allen
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f500426158 |
Update to v101r34 release.
byuu says: Changelog: - PCE: emulated gamepad polling - PCE: emulated CPU interrupt sources - PCE: emulated timer - PCE: smarter emulation of ST0,ST1,ST2 instructions - PCE: better structuring of CPU, VDP IO registers - PCE: connected palette generation to the interface - PCE: emulated basic VDC timing - PCE: emulated VDC Vblank, Coincidence, and DMA completion IRQs - PCE: emulated VRAM, SATB DMA transfers - PCE: emulated VDC I/O registers Everything I've implemented today likely has lots of bugs, and is untested for obvious reasons. So basically, after I fix many horrendous bugs, it should now be possible to implement the VDC and start getting graphical output. |