What 'RT' and 'HDR' have to do with fixing obscure graphical issues in 20-year-old PS2 games

I hope you weren't expecting some special chocolates for Valentine's, folks, because instead I've got you the same thing I get you every other weekend: a heaping handful of emulation news!

Because I'm selfish, I did get a chocolate for myself the other day — on a short getaway to the scenic northern California coast, I couldn't resist the call of an Angela Lansbury, aka a dark chocolate truffle with orange-infused ganache on the inside. Mmm! Before wrapping up this issue, I disconnected from games for 24 hours to go smell the sea (touching grass for sophisticates) in Mendocino and Fort Bragg, highly recommended as quaint getaways full of cute shops and cuter inns.

To be honest, the chocolate truffle was only okay — I don't think it lived up to the Angela Lansbury name. If you got some Valentine's chocolate I hope it really blew your mind!

This week popular Android DS emulator DraStic made some ripples by, well, disappearing itself. It's gone from the Play store, now, after being available free for roughly the last 11 months. Before that it was paid; DraStic's developer made the change after the Yuzu lawsuit last year, and said at the time that they intended to remove it from the store. I'm surprised it ended up taking a year, but I suppose the urgency seemed to pass after the heat of the moment. While it's a shame to see it go, an 11 month warning makes this not exactly a shock.

The real sour point of DraStic's removal is that lead developer Exophase said they'd open source the code "in short order," and that has yet to happen. Hopefully it does, now that the emulator's no longer available.

In brighter news of once-exclusive information being made public: How would you like to trawl through an archive of 2,044 arcade machine manuals? Thanks to Peter Mount, and pointed out by the Internet Archive's Jason Scott, such a treasure trove is now on the archive. Go learn how a Zaxxon machine works or look at schematics for TMNT: Turtles in Time or appreciate the sweet-ass cover art for The Electric Yoyo or Super Bug. I don't know if any of these are rare or previously unscanned, but I have to imagine at least one or two of them will come in handy for MAME's developers!

And now for something completely different: this week's issue is focused on a recent improvement for PCSX2 that caught my eye, and we've also got another nice crop of fan translations to appreciate. That scene's been off to a hell of a start this year!

The Big Two

1. Coming out of retirement for one last job: Tackling some of PCSX2's problematic faves

Last time I talked to former lead PCSX2 dev Refraction, he was retiring from the emulator project after 19 years of service... or so he thought. But just when he thought he was out... well, he pulled himself back in. Sometimes it's hard to stay away, huh?

A few days ago, a fix from Refraction called "Reduce number of copies for HDR" was merged into PCSX2, resulting in huge frames per second performance boosts for a select list of games that includes Sly Cooper 2 & 3, Soul Calibur III, FromSoftware's Echo Night: Beyond, and the legendary Big Mutha Truckers.

You might already be confused by the mention of HDR for an early 2000s game console, so let me throw in a little more confusing terminology first before we explain everything.

"After 19 years I've decided I've had enough and want to move on to trying new things," Refraction told me this week. "However, RT in RT was one thing I was working on before I left. The problem was due to its complexity, I was worried it would get left to rot as other changes basically make it impossible to keep up to date, so I returned in order to finish it. There was a lot to do in terms of making sure it behaved correctly and the heuristics didn't explode on every other game which didn't need it, I have had a couple of months of whack-a-mole trying to make sure everything I have dumps for still works. The HDR thing happened in the meantime on a whim after a short conversation, it was just meant to be a proof of concept."

Quite a happy accident then, this little speed-up — but are we now talking about HDR and ray tracing? What gives? Let's tackle the HDR bit first, which is not the same as the high dynamic range you're used to on your TV.

The PS2's graphics processor performs a process called blending to achieve different graphical effects — transparency, for example — and its blending unit supports "9 bits of accuracy," which is "something PC GPUs don't do by default (we have 8 bits per channel for standard texture formats), so we convert the texture so it can do this," Refraction explains. So this fix is basically about converting color data from the broader 9-bit range that makes sense to the PS2 to the smaller 8-bit range that makes sense to your graphics card. That process was where the potential performance problem arose:

"As for reducing the number of copies, we were performing the conversion from a normal format to a Float16 format, then back again, every single draw that needed it. The change that was made basically tried to keep it converted to Float16 as long as it needed to be before converting back, to reduce those copies, since these slowed things down a lot, especially for DirectX renderers. That said, this was only required in a scenario where the colours were masked/looped instead of clamped to 0-255, so there's only a few games that benefit from it."

Okay, so what does that last bit mean — "masked" vs. "clamping" and "0-255"? Those numbers refer to an RGB color range; in most games if the GPU performed a blend and the resulting texture color would fall outside that range — say 257 instead — it would be programmed to simply cap at 255. But some games used a technique called a bit mask to "wrap around" in the code back to the start of the range in such a way that the code indicates "1, but actually 257" (remember the range starts with zero) instead of just "eh, fuck it, 255 is close enough." Even a process as seemingly simple as telling your GPU what color to draw can be pretty dang complicated!

But as Refraction said, this nice jolt of found frames for a few games was really just a side benefit to his main task in the last few months, which was shipping a complicated feature he'd started last year and didn't want to see go to waste. The big one deals with "RT," which means Render Target, not ray tracing. This project is fixing some major graphical problems that have plagued games in PCSX2 forever:

"Anything we draw to in the hardware renderer is known as a 'Render Target.' When the hardware renderers were implemented, they were expected that the start addresses for the draws would identify the render target we want, anything else would be considered a new render target. However a lot of games will offset the start address inside a render target area for things such as texture/channel shuffles (techniques for swapping colour channels around or modulating based on a single colour channel (RGBA)). This was never implemented before because it brings further complexity, such as modifying the input coordinates to account for the offset, but there's also chances they really are new render target, and it's been misinterpreted. However fixing this resulted in a bunch of games having their post processing effects fixed, in some cases changing the games from completely unplayable in hardware rendering, to playable, such as Stolen and Hitman Contracts."

Check out some of these comparisons from the Github thread, showing the before and after of the fix:

There are tons more examples in the thread, with quite a few games that were busted in splitscreen now working, others that couldn't upscale beyond their native resolution now scaling properly, and more with distracting graphical issues cleared up. Here's an incomplete list of problems solved:

• Big Mutha Truckers - No longer requires a CRC hack for half screen shuffle
• Death by Degrees - Lighting and fog effects post-processing (top left corner) are fixed (CRC can be removed)
• Driv3r - Doesn't need such a cacophony of fixes, just CSBW 4/2 + Tex in RT
• Hitman Blood Money - Post-processing and shadows fixed (still needs CRC for weird corner uploading thing, but may be more fixable these days)
• Hitman Contracts - Graphics completely fixed
• Jak X - Player 2 now visible
• Peter Jackson's King Kong - The Official Game of the Movie - Pretty much fixed with RT in RT
• Knights of the Temple - Now needs tex in RT
• Manhunt 2 - Post-process (top left corner) lighting fixed
• Onimusha - Warlords - FMVs seem to not flicker (game currently uses SW FMV)
• Sniper Elite - Second player lighting overlay fixed
• Stolen - All graphics processing is fixed, lighting, etc. Speed is also not terrible
• Spiderwick Chronicles - Half screen problem in book fixed
• Suikoden III - Half screen black and white effect fixed
• SWAT - Global Strike Team - Player 2 colours corrected
• Taiko no Tatsujin Bang Tap - Lighting overlay (top left corner) fixed
• Tekken 5 - Fire effect can now be used upscaled and half screen fire effect problem is fixed
• TOCA Race Driver 2 - Shadows fixed
• Time Crisis 3 - Post-processing looks correct now
• Tomb Raider - Legends - Fixes for post lighting effects not covering the screen in some levels and goggles
• Wrath Unleashed - Fixes colours
• WRC 3 - Half screen fog effect fixed

Refraction's RT in RT support isn't merged into PCSX2 just yet, but it shouldn't be long before everyone can take advantage of these improvements, and in some cases play games that haven't really been viable to emulate for PCSX2's lifetime. If Refraction truly sails off into the sunset after this one, he'll be leaving behind a job well done.

2. Sega Saturn on MiSTer supports modern light guns, composite blend, and Titan

After that lengthy lesson in PCSX2 minutia I'm going to keep this one short, as Danthrax over at Sega Saturn, Shiro! has already written a fantastic breakdown of recent updates to the Sega Saturn MiSTer core. There's a lot going on here: core developer Sergiy Dvodnenko has recently gotten some help from other contributors to add some notable features:

• Suppport for modern light guns that work on flatscreen TVs, in addition to its existing support for the official Stunner on CRTs: Danthrax notes the Gun4IR, Sinden, and Wii Remotes can all be used by mapping them as virtual guns in the input menu
• Initial, in-progress support for ST-V Titan, the arcade version of the Saturn hardware. This is still early, but will eventually mean some exclusive arcade games will be playable on the core
• A composite blending graphical feature, if you wanna blur up them pixels

Beyond those marquee additions, there are also a lot of individual game fixes including Dead or Alive, Saturn Bomberman, Dark Savior, Radiant Silvergun, and Initial D.

The only catch? These changes aren't on the core's stable branch, so you're going to have to hop into the MiSTer FPGA Discord's Unstable Nightlies channel and download the latest build from there. Just in the last 24 hours as of this writing, contributor Kuba-J has added a new horizontal crop option to hide the visual artifacts that appear at the edges of some Saturn games, including Nights Into Dreams. They're keeping busy!

Patching In

PPSSPP sounds smarter – An overhaul to how volume control works in PPSSPP now means, among other things, that turning the volume up/down will just affect game volume, not menu sounds. The volume curve is now also "more intuitive" and there's a separate setting for UI sounds. I find overly loud menu bloops extremely annoying, so this is all appropriately quiet music to my ears.

RPCS3 gets online upgrades – The PS3 emulator's online matchmaking service (written about in a previous ROM!) now supports passworded rooms, private slots, and IPv6 support for connecting to multiplayer lobbies. Check the compatibility list for supported games!

Ares v142 runs the gamut – The dizzying number of systems Ares emulates means updates are wide-ranging, and that's certainly true of this one. Fixes for FM synth for the Sega Genesis leave no known audio issues; there's improved PC Engine performance; and support for a new arcade board, the SETA Aleck64. A couple nice higher level additions:

• Support for searching the game list for Arcade cores
• Adjust the “overscan” option to crop strictly to the “active frame” area that the emulated system renders game content onto, rather than the area one might see using typical contemporary hardware (Famicom, Super Famicom, SG-1000, Master System, ColecoVision, My Vision, MSX)

Core Report

ZX Spectrum on the Analogue Pocket? – Yep, it's a thing! Developer dave18 has been working to bring over the MiSTer core to the Pocket. It's in beta, but available now and seemingly making quick progress.

NES Analogizer Pocket core updated – A big update to the OpenFPGA core for the NES includes "many memory mappers fixes" as well as "added support for Analogizer configuration file, PSX SNAC gamecontrollers and NES SNAC Zapper lightgun." That's all for taking advantage of this adapter thingamajig, if you're not familiar.

Primal Rage 2, now in MAME – Or, rather, soon in MAME. The next release will get the arcade fighter working with "No more badly hacked up old ancient MAME versions needed," says longtime developer MameHaze, crediting the work to contributor smf. Unfortunately, the first game's tough security means it's not yet easily emulatable.

Translation Station

The Adventure of Little Ralph – Gosh I hate it when humanity's desperate resistance is virtually powerless before the power of darkness, don't you? Anyway, enough about current events, we've got a new PS1 platformer to play! This translation patch handle everything but the credits, and the game looks pretty alright! It doesn't singlehandedly disprove the ol' "Sony hated 2D graphics" nugget but is a good reminder that the PS1 did have some good 2D games, despite the push for 3D. My pal Ray Barnholt says The Adventure of Little Ralph is "Obscure PS1 Game You Must Play #1 for like 18 years now," so give it a look!

Appareden: The Sacrosanct Dragon – You know I love me some PC-98 pixel art, and here's a whole-ass RPG full of it from a veteran translation team that last put out a patch more than five years ago (you may have seen their translation of the very cool lookin' CRW Metal Jacket). Beauty:

Considering how few of these games are sold in original or re-released form, I don't have any qualms about pointing to a repository of pre-patched fan translated games (including Appareden) to use in the PC-98 emulator of your choice. Translation team 46okumen actually wrote a handy guide to getting it going. Hopefully someday Project Egg becomes more accessible in English, because I'd love to see easier access to old Japanese PC games. People will pay for them!

Kamen Rider SD: The Ambitions of Grand Shocker – If I had to guess, out of the 2000+ people who read this newsletter there are probably 2 who might actually play a superdeformed NES game about Kamen Rider. It looks like part board game, part RPG? I'm gonna be honest, I'm including this one specifically because a couple years ago I bought a Kamen Rider classic manga collection on a whim and discovered the art absolutely fuckin' rips. There's like 40 years of Kamen Rider TV shows and I've never watched any of them, but that B&W art, impeccable.

Good pixels

That Kamen Rider NES game got me curious how many adaptations of the series there have been over the years, so I went hunting for some screens. How many ways can you depict ol' bug eyes? Well, considering there have been 35 TV shows and a bunch of movies and all kinds of other media in addition to the manga, the answer is "a few!"

Henshin-a-go-go. 💽

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