Decent port of Street Fighter II possible?

[mcgeezer]

Originally Posted by sandruzzo

Yes. One background, and 2 static frames, with colors mapped like this: first 16 colors for background, second 16 for static frames

So you want them mixed down to 16 colours then?

[sandruzzo]

Originally Posted by mcgeezer

So you want them mixed down to 16 colours then?

No, no, just mapped like sf2 Amigas' colors which use 32 entries: 0-15 background, 16-31 players

[Tigerskunk]

Originally Posted by sandruzzo

No, no, just mapped like sf2 Amigas' colors which use 32 entries: 0-15 background, 16-31 players

It doesn't look like that in your Dpaint image.

[sandruzzo]

Originally Posted by Steril707

It doesn't look like that in your Dpaint image.

I would like to test speed with 2 big players and see if we can hit 50hz with 5 bitplanes

[britelite]

Originally Posted by sandruzzo

I would like to test speed with 2 big players and see if we can hit 50hz with 5 bitplanes

Why do you need any actual graphics to do a speed test?

[sandruzzo]

Originally Posted by britelite

Why do you need any actual graphics to do a speed test?

To have a decent visual test...

[britelite]

Originally Posted by sandruzzo

To have a decent visual test...

But isn't it the speed you want to test? Just check how large the sprites should be from the sprite sheets, open a 5bpl screen and copy two chunks of the desired size around the screen. No need to fiddle around with graphics.

[Tigerskunk]

Originally Posted by britelite

But isn't it the speed you want to test? Just check how large the sprites should be from the sprite sheets, open a 5bpl screen and copy two chunks of the desired size around the screen. No need to fiddle around with graphics.

But then there would be no entry on IndieRetroNews claiming "OMG! STREET FIGHTER 2 FOR AMIGA IS COMING!"...

[mcgeezer]

Here you go Sandruzo...

Knock yourself out.




Done in 8 colours (which I like)

http://www.siesmicminds.com/download...SAN1_8cols.iff


And 16 colours...

http://www.siesmicminds.com/download...AN1_16cols.iff

Enjoy.

Geezer

[sandruzzo]

Originally Posted by mcgeezer

Here you go Sandruzo...

Knock yourself out.




Done in 8 colours (which I like)

http://www.siesmicminds.com/download...SAN1_8cols.iff


And 16 colours...

http://www.siesmicminds.com/download...AN1_16cols.iff

Enjoy.

Geezer

thanks! On it!

[LongLifeA1200]

I've never played any other version of Street Fighter 2, so I'm none the wiser as to what I'm missing out on, all those years ago. I'm left with a happy memory of the game.

If this is just to prove that OCS/ECS can keep up with the big boys (arcade machines) of the day, then I hope it doesn't just stop at there. Adding more characters, locations and story-arcs would make all the effort so much more worthwhile.

[trixster]

Just has a play of Super Street Fighter 2 DX. Blimey, it’s surprisingly not awful the control are ok with 6 buttons, all the animations and speed is there. The music and sound is poor, the sprites look small compared to MD/SNES and the colours are weak but overall it’s massively better than SF2 or SSF2Turbo

[zero]

Originally Posted by trixster

Just has a play of Super Street Fighter 2 DX. Blimey, it’s surprisingly not awful the control are ok with 6 buttons, all the animations and speed is there. The music and sound is poor, the sprites look small compared to MD/SNES and the colours are weak but overall it’s massively better than SF2 or SSF2Turbo

It is, isn't it? The main things it gets right are the frame rate and timing.

SF2 actually runs at a different speed internally. The turbo modes just skip frames, in odd ratios like 3:5, so it has to run at 90+ FPS internally even if only 60 frames are drawn.

Even normal speed at 60 fps is quite an achievement.

[ReadOnlyCat]

Originally Posted by alpine9000

I guess what I’m saying is that the majority of people have one button sticks. A small percentage have two button sticks and a smaller still percentage have cd32 compatible pads.

This really limits the audience for an OCS game.

Frankly, I think these kittens should be whipped until they buy a proper modern controller rather than suffer with these stupid one button ones.
There was no reason to limit oneself to one button controllers back in the day and there is even less nowadays.

When my Amiga games ship, they will support MegaDrive 6 buttons controllers and I expect players to invest in proper gear to play them.

Originally Posted by zero

Also the CD32 controller is a pain to read. It's very slow, requiring multiple slow operations to read all buttons. If it was back in the day and I was expecting big sales I'd think about using a parallel port adapter for Megadrive 6 button pads.

Yup, moreover MegaDrive controllers adapters are very easy and inexpensive to make, MegaDrive controllers are cheap, plentiful and durable. There are no reasons not to use them instead of the CD32 joypads.

Originally Posted by roondar

I've thought about a better SFII port a while back and my idea was to have a number of 'key frames' for the fighter animations and pre-calculate the delta between these frames and the next ones in sequence. Either on a 16x16 grid base, or on a complete fighter base*.

Then, during the game you'd 'unpack' those delta's in real time. This might be a complicated affair, but it seemed doable to me from a Blitter/CPU overhead.

This is very doable. Many people think that rendering SF 2 on the Amiga may be difficult but it is a piece of cake:
- sprites are not that big, easy for the blitter to blit them in and clear at 50Hz
- animations are actually *very* sparse, objects positions change between frames but the same keyframe is used from 5 to sometimes 20 frames! There is plenty of time in between keyframe changes to do a lot of things (unpack the next frame, flip it, etc.)

Originally Posted by Master484

I think the original Us Gold Street Fighter 2 World Warrior conversion got many things right.

Except for the crappy frame rate and gameplay. (agree on the technicalities!)

Originally Posted by Master484

So in a way it was a good conversion, because it had almost everything that people would want from a SF2 conversion. And it shows that the A500's small Chip RAM can handle this game in 32 colors.

I must disagree, the only criteria to judge a game on is "does it play well?", all the rest is just secondary fluff. If SF2 ECS was monochrome and otherwise playing exactly like the arcade it still would be a better game than what we got.

SF2 ECS does not play well, it is slow, collisions are fiddly, controls do not always respond correctly. Its pace has nothing to do with the arcade original.

Originally Posted by Master484

I wonder if the slowness was caused by the real time character X flipping? It could be, because how else could they manage to get all those frames into a 32 color game?

Flipping is not a problem, even if every animation key frame had to be flipped all the time and if there was no room for a 128KB flipping table, there would still be plenty of time to do it on a basic A500.
It is slow because like 99% of US Gold subcontracted games, it was coded like crap for the cheapest possible price by a second rate studio.

Originally Posted by Master484

But other games like Mortal Kombat 2 show how fast a 32 color game like this can run. So the higher running speed could have been possible to achieve, if they had more time to optimize the code.

This is not an optimization problem, this is really a "do not do stupid things in the first place" problem. 99% of games by US Gold suffer from the exact same speed and quality issues.

Originally Posted by sandruzzo

If someone is willing to give me one SF2 BAckround with 2 static players' frame I'm willing to see if we can get 50hz with 32 colors mode

Do not even bother testing: the SF2 sprites are not really that big that you could not move two of them at 50Hz.

Battle Squadron moves more pixel data every frame than SF2 does (if we exclude SF2 animated background).

[zero]

Originally Posted by ReadOnlyCat

Yup, moreover MegaDrive controllers adapters are very easy and inexpensive to make, MegaDrive controllers are cheap, plentiful and durable. There are no reasons not to use them instead of the CD32 joypads.

Is the Megadrive pad that much better though? You have to do multiple read cycles to get the additional buttons. It's not quite as bad as the CD32 bit it's not great either.

[Hewitson]

Originally Posted by zero

Is the Megadrive pad that much better though? You have to do multiple read cycles to get the additional buttons. It's not quite as bad as the CD32 bit it's not great either.

In terms of programming it may not be ideal, but it's a fantastic controller to play with. Extremely comfortable to use, unlike the CD32.

[roondar]

Originally Posted by Hewitson

In terms of programming it may not be ideal, but it's a fantastic controller to play with. Extremely comfortable to use, unlike the CD32.

This is extremely true. When I finally got access to a real Mega Drive a few years ago I was stunned by the difference in quality between its pad and that of the competition. It's not just better than the CD32 pad (which always was pretty awful, in no small part due to the terrible D-Pad) but also than the SNES one and the PC-Engine one.

The MD one just sits in the hand so much better than any of them. It seems designed for use by humans rather than for looking nice.

[str0m]

Vaguely on topic, I have one of the new 8bitdo M30 wireless MD pads and that works with no noticeable lag on my CD32 using one of the MD->CD32 adapters

https://www.amazon.co.uk/dp/B07HB1XF...740111_TE_item

[DanScott]

Originally Posted by ReadOnlyCat

Battle Squadron moves more pixel data every frame than SF2 does (if we exclude SF2 animated background).

Battle Squadron runs at 25fps... AFAIK only the hardware sprites and left / right scrolling are updated at 50fps

As for unpacking the animations, this is easily doable, however the 1st frame of an animation sequence would need to be available instantly to initiate the animation. Probably the first frame would need to be unpacked, or very simply packed so it can be decoded very quickly

[roondar]

Originally Posted by DanScott

Battle Squadron runs at 25fps... AFAIK only the hardware sprites and left / right scrolling are updated at 50fps

As for unpacking the animations, this is easily doable, however the 1st frame of an animation sequence would need to be available instantly to initiate the animation. Probably the first frame would need to be unpacked, or very simply packed so it can be decoded very quickly

Right, I agree. So in my idea the first frame/several key frames would be available 'instantly'/lightly packed/unpacked and then the delta's wouldn't be.

As for frame time use, I did a quick back-of-the-envelope calculation. A 80*96 sprite (which is roughly how big the SF2 sprites seem to be) would take roughly 17K DMA cycles if blit using a standard blitting algorithm*, a 5 bitplane display would take roughly 27K cycles and there are roughly 68K available on a PAL Amiga, after deducting audio/refresh but not sprites.

So displaying the screen + 2 character sprites would take some 90% of available DMA cycles unless tricks are used. Which is why I think an AGA version would probably be a better fit.

*) Sandruzzo is considering an algorithm that would allow at least one of the two characters to be blit significantly faster.