Coder shows possible way in which some elements of Street Fighter 2 might be possible

[DanScott]

Originally Posted by alain.treesong

EDIT : and of course the blitter which is dedicated to the characters can of course flip some images to manage the double direction

Blitter can't flip horizontally, only vertically, and even that's not so easy when using interleaved bitplane mode... you have to do each bitplane seperately.

Flipping with the CPU is possible though, and could be done "ahead" of time... so when you trigger an animation sequence playing, the subsequent frames are flipped in advance into a buffer (could even be decompressed on the fly too... that's been talked about before with regards to this kind of game). Also masks need flipping too... this only needs to be done for one plane, and then the flipped data copied to the other planes. In fact, perhaps only one plane of mask needs storing anyway, and the full 4 plane massk can be constructed on the fly ahead of time too.

One thing that is definitely possible, is that the masks are not needed for one character... that character can be just blitted straight to the playfield quickly. Only the 2nd character would then need masking (assuming that one character is ALWAYS plotted first)

[Valken]

Just amazing what can be done with time, creativity and breaking walls to limits.

Bravo to the developer.

I mean the A1200 and 4000 existed at the same time. Imagine if developers said 2 or 4 meg fast RAM with 68020 or 68030 with this demo, back then...

Let's PUSH it a little to get the results we WANT vs limited by the lowest common denominator within a realizable goal.

Look at how "killer apps" sold a ton of gear in the past:

King's Quest, Wolfenstein - PC
Doom - 486, VGA
Monkey's Island, Wing Commander - VGA and Soundcards
Quake - Voodoo cards

I could see a revival if we just up the spec to a reasonable level while keeping the Amiga chipset for nostalgia.

[Neil79]

Originally Posted by tarr

http://www.indieretronews.com/2021/0...of-street.html

Thanks matey!!

[alain.treesong]

Originally Posted by DanScott

Blitter can't flip horizontally, only vertically, and even that's not so easy when using interleaved bitplane mode... you have to do each bitplane seperately.

Ah yes of course.
I was misled because the only language I know on the Amiga is Amos and the flip is associated with the definition of a bob. So this must be done effectively with the 68000. Thank you for the clarification :-)

In any case here with a 020 at 14Mhz, it probably seems feasible without too much trouble. There is still the possibility of having both senses in memory.This will reduce the number of different movements, which is not incompatible with standard amiga joysticks: so comes another question with the problem of the number of buttons.

Decidedly it's still quite funny to talk about these things in 2021 :-)


Edit : the idea of a single mask by putting always the same character first (because the 4 planes are empty, if I understand well) is a good idea. Moreover with a screen dedicated to the characters, the background doesn't need to be restored. I don't remember if it is said in the video (probably)

[mcgeezer]

If someone can come up with a video of the stock Amiga A1200 showing two players being controlled with all of the frames from the arcade then i’ll be suitably impressed ( dont even have to worry about any backgrounds)

Until then, all the copper waits in the world wont convince me that the a1200 can run street fighter 2 even close to the arcade.

The a1200 has too little memory and too few buttons to make it a viable port.

[Tsak]

Exciting project.
A couple clarifications: The narrator and author of this video isn't the coder (as the title of this thread suggests) but an artist, Pixel Shade (he's also working with me and KK in the Dread project btw). This demo started as an experiment, while trying to see what could be possible on an AGA machine.

Other than that the biggest problem with this going forwards would be to get the gameplay right. To me that's where the other ports failed completely. Graphical fidelity, colors on screen, parallax and animated backs are all pretty nice but secondary imho. Getting all the character frames in is much more important and implementing the logic as well as collision detection e.t.c. would be a monumental task, even if sources are found or reverse engineered.
Having said that it would be still interesting to just get the running demo out, with all the things Pixel Shade showcased in his video.

[DanScott]

Originally Posted by mcgeezer

two players being controlled with all of the frames

That's practically 50% of the game

[skyzoo73]

Originally Posted by mcgeezer

If someone can come up with a video of the stock Amiga A1200 showing two players being controlled with all of the frames from the arcade then i’ll be suitably impressed ( dont even have to worry about any backgrounds)

Until then, all the copper waits in the world wont convince me that the a1200 can run street fighter 2 even close to the arcade.

The a1200 has too little memory and too few buttons to make it a viable port.

I don't think a stock Amiga 1200 is enough, a lot of fastram will definitely be needed.

[mcgeezer]

Originally Posted by DanScott

That's practically 50% of the game

To clarify, two characters from the game.

Particularly, that one with the dangly long arms must feature.. daishu or whatever he’s called.

[Retro1234]

Super Street Fight 2 not Turbo got the gameplay right if you don't like the gameplay of this version don't even attempt a port.

[mcgeezer]

Originally Posted by skyzoo73

I don't think a stock Amiga 1200 is enough, a lot of fastram will definitely be needed.

And this is my point, the purpose of the video is to prove a stock a1200 could have done a very good version of street fighter. It can’t because there’s not enough memory.

[alain.treesong]

Hmmm, if we consider Shadow fighter (http://hol.abime.net/1888) which runs in dual playfied (so characters with 7 colors) and with 512K of chip ram, by analogy, isn't it possible to have 2 characters of SF2 in 16 colours with 2 mega ram chip? Personnaly, I think it is possible.

[Tsak]

Originally Posted by mcgeezer

If someone can come up with a video of the stock Amiga A1200 showing two players being controlled with all of the frames from the arcade then i’ll be suitably impressed ( dont even have to worry about any backgrounds)

Until then, all the copper waits in the world wont convince me that the a1200 can run street fighter 2 even close to the arcade.

The a1200 has too little memory and too few buttons to make it a viable port.

I think the controls shouldn't be a huge issue, there's the cd32 pad option which could facilitate such a game and also keyboard (because, why not? )
Getting it to work in anything less would be a challenge indeed and definitely a downgrade from the arcade.

I agree memory would be the biggest bottleneck for such a project though. Afaik the original arcade does reuse parts, so a similar approach could be taken here. Still compromises would have to be made though. Just have a look at these massive anim sheets : https://www.spriters-resource.com/fullview/38136/
Plus the work required to resize, recolor, manually repixel/tweak, crop and reassemble these frames into parts would be another massive task.

[neoman]

Nice to see your discussions here =)

Of course there will be compromises (if we continue, not sure yet). The aim is to do it as good as possible on the stock A1200. And if we need to omit an animation frame which is barely noticable because there are memory limits then we do it because the main aim is to achieve the same playability.

And again, helping hands with reversing the ROM to get access to hitboxes or internals about movements are welcome.

[Antiriad_UK]

I love the tech work - learning stuff too! But really worth spending more time on a live IP where they will definitely get the project taken down wasting all your time? I’d use it for something original

[Tigerskunk]

Originally Posted by skyzoo73

I don't think a stock Amiga 1200 is enough, a lot of fastram will definitely be needed.

Or playing it on MAME on any half decent PC.

Works like a charm here.

[Retro1234]

if Tsak is on board then I guess it's probably a sound project

this site has some info on ripping the HitBoxes
https://www.smwcentral.net/?p=viewthread&t=33039

iirc there was another site that has the A.I info but I can't find it.
ok A.I stuff https://sf2platinum.wordpress.com/20...the-ai-engine/

it might be worth some time looking to see how hard it would be to rip from SSF2 Amiga version the A.I.

[mcgeezer]

On the subject of the tech in the video, I would probably do it like this.

Dual Playfield mode with fetch mode x1 and 64 wide sprites.

Back playfield used for background image, Front playfield used for foreground animations. For animations I would probably just cut out the animated sections where needed and change the bitplane pointers per animation. Each scene would need some sort of driver to determine what animations need to be done and any copper effects (easy to do).

Dedicate all blitter and cpu time to reconstructing the player sprites from 16x16 tiles, 4 even sprites for the 1st player, 4 odd sprites for the 2nd player, this then allows for 16 colours dedicated per player (64 colours in total without copper effects), each player then has maxium 128x224 size.

No shifting is required because blits are placed in the hardware sprites and only copy mode is required, this negates the need to hold sprite masks and saves CPU/BLIT time massively. With hardware sprites you negate the need for double buffering - again, massive memory saver.

I'm not a fan of the genre or Street Fighter so some assumptions that I make are likely wrong. Firing objects across the playfield may be tricky, haven't thought that much ahead.

But keep in mind.... everything HAS to work in 2mb of CHIP ram otherwise - NOBODY WOULD HAVE PURCHASED THE GAME!!!!

[Retro1234]

one of the ideas I like about master464 demo was the players were sprites this ensured that you had a fast game with large characters but this method I always assumed because of the limited number of sprites you can't store the frames in reusable parts, only whole so taking up more memory.

[mcgeezer]

Originally Posted by Retro1234

one of the ideas I like about master464 demo was the players were sprites this ensured that you had a fast game with large characters but this method I always assumed because of the limited number of sprites you can't store the frames in reusable parts, only whole so taking up more memory.

You can store the frames in parts, you just need to reconstruct the hardware sprites with the parts using the CPU/Blitter.

As an aside, I wouldn't mind knowing how much memory of the A1200 was used up for this "technical demo".