Crazy idea to improve speed on games for AGA machines

[jotd]

For some games that are slow, because lots of blitting / 32 colors / EHB and all, those could be sped up on AGA machines by changing FMODE = 0 to FMODE = 3 (and also adjusting modulo as possibly bitplane addresses)

I way trying to add FMODE=3 to my supercars 2 AGA hack (I lazily retained old FMODE=0 setting), and while testing on real hardware, I had the impression that the game was much smoother.

Paraj already did such work in Killing Cloud (besides rewriting the part of the 3D rendering engine ).

AGA games probably already use that mode (well, we could have surprises) but if you have ideas about games that are slow and could be made faster, please do tell.

[DanyPPC]

Great idea !

[Toni Wilen]

It should be relatively easy if game does not use horizontal scrolling.

Horizontal scrolling can make it very complex task. Bitplane pointers must be 8 bytes divisible, different BPLCON1 range (0-15 -> 0-63). Horizontal scrolling also requires smaller DDFSTRT (than OCS/ECS) = lost sprites.

[jotd]

Originally Posted by Toni Wilen

It should be relatively easy if game does not use horizontal scrolling.

Horizontal scrolling can make it very complex task. Bitplane pointers must be 8 bytes divisible, different BPLCON1 range (0-15 -> 0-63). Horizontal scrolling also requires smaller DDFSTRT (than OCS/ECS) = lost sprites.

okay, goodbye Silkworm 3D games not using the blitter (Red Zone) won't benefit from that at all either.

One difficult part is to find proper modulo settings and DDFSTART/STOP but also if bitplane is not 8-byte aligned, or number of lines is not divisible by 8, this means that more memory is required for the screens, so all the constants after the screen data will be overwritten unless they're shifted...

All this work is rather easy when you have the source, but without it, with all precompiled address calculations, this is not so trivial.

If anyone can share some (good) titles that notoriously crawl/could be faster (ex: Prince of Persia, but that one runs much faster with fastmem reloc already), please yell.

Maybe Bitmap Brothers games (Gods, Magic Pockets, Speedball 2). Not sure it would improve the framerate though.

[kremiso]

what about the slowdowns in Lotus3?

[jotd]

Lotus 3: one of the rare games of which I have the source code

When do those slowdowns occur?

[vroom6sri]

Am I right in thinking that Fighter Bomber uses the blitter in its 3D engine? Could that be made smoother?

[jotd]

Fighter Bomber was already heavily processed by paraj & me: relocation to fastmem and usage of fmode=3 if AGA chipset. Nothing to optimize further here. Game is just too ambitious or too badly written.

Maybe you didn't test the latest whdload version ? It "flies" at around 10 fps on my A1200/060. Not great but better than the previous slideshow of a game that it is originally.

[vroom6sri]

I had not seen that!!! Cool. I managed to get your new version working (never done a WHDload install before - always used pre-done ones) and it's a HUGE improvement over the original. It's actually nice to play!

I've got an A1200 with ACA 1230/56 and the FPS fluctuates between around 10 & 25! I loaded up the original to compare and it is hideous.

Thanks for this new version.

[nikosidis]

Could it work for Chaos Engine?

[jotd]

Originally Posted by vroom6sri

I had not seen that!!! Cool. I managed to get your new version working (never done a WHDload install before - always used pre-done ones) and it's a HUGE improvement over the original. It's actually nice to play!

I've got an A1200 with ACA 1230/56 and the FPS fluctuates between around 10 & 25! I loaded up the original to compare and it is hideous.

Thanks for this new version.

You're welcome. How could they publish that turd as-is back in the days? It's got good reviews, they probably played the PC version

Originally Posted by nikosidis

Could it work for Chaos Engine?

Yes, but not sure I want to do it. The CD32 version is AGA and runs in fastmem already from whdload. I just checked and in-game already uses 64-bit fastest fetch mode too.

Some argue that the ECS version is better color wise. It also runs from fastmem, but obviously doesn't use FMODE fetch optimization. Not sure if it's worth it.

[kremiso]

Originally Posted by jotd

Lotus 3: one of the rare games of which I have the source code

When do those slowdowns occur?

i think to remember when a track was longer than a certain size, or with a good amount of details, the engine suffered on A500

also with many tracks in the league, so pre-generated

iirc all the 'future' setting tracks had issues too?

too much time has passed from the last play with this one

[jotd]

On A500 I can't help. If it crawls on A1200 something could be done, specially running from fastmem (if CPU issue) & enabling fmode=3 (if DMA/blitter issue)

[robinsonb5]

I'm wondering whether Xenon 2 could be turbocharged? (And if so, would it become more or less playable?)

[nikosidis]

Originally Posted by jotd

You're welcome. How could they publish that turd as-is back in the days? It's got good reviews, they probably played the PC version




Yes, but not sure I want to do it. The CD32 version is AGA and runs in fastmem already from whdload. I just checked and in-game already uses 64-bit fastest fetch mode too.

Some argue that the ECS version is better color wise. It also runs from fastmem, but obviously doesn't use FMODE fetch optimization. Not sure if it's worth it.

Yes, exactly. The AGA version look horrible. That is not something I say cause I do not have AGA computers. Would love to see the OCS version without slowdowns.

[vulture]

@jotd

Maybe the ICE racers could benefit from this (Turbo Outrun, Cisco Heat, Chase HQ II, Hydra) and make decent games out of duds!

[jotd]

Originally Posted by vulture

@jotd

Maybe the ICE racers could benefit from this (Turbo Outrun, Cisco Heat, Chase HQ II, Hydra) and make decent games out of duds!

WinUAE is a good test as code running in chip or fast makes no difference in speed, and I can't say for sure but it's very likely that FMODE speed isn't emulated. FMODE is emulated because if you misalign bitplanes or sprites you get trashed graphics, but take Supercars 2 AGA for example, on WinUAE it's always been smooth even with FMODE=0 (ECS fetch).



There's one way to know: play them under WinUAE and see if they're any faster this way. If they still suck in WinUAE then it's no use. It usually helps to decide which game is worth working on.

[gimbal]

Originally Posted by vulture

@jotd

Maybe the ICE racers could benefit from this (Turbo Outrun, Cisco Heat, Chase HQ II, Hydra) and make decent games out of duds!

Is Turbo Outrun really going to be decent when the frame rate is improved? It's still going to be a racer with very short tracks and only 2 mediocre pieces of music Maybe JOTD can hack a turbo boost into Lotus 1

[alexh]

Originally Posted by robinsonb5

I'm wondering whether Xenon 2 could be turbocharged? (And if so, would it become more or less playable?)

It would be great to see a 50Hz FastMEM / AGA version BUT all the work involved and it's not a particularly good game.

[vulture]

Sure, gonna try them out.

Originally Posted by jotd

WinUAE is a good test as code running in chip or fast makes no difference in speed, and I can't say for sure but it's very likely that FMODE speed isn't emulated. FMODE is emulated because if you misalign bitplanes or sprites you get trashed graphics, but take Supercars 2 AGA for example, on WinUAE it's always been smooth even with FMODE=0 (ECS fetch).



There's one way to know: play them under WinUAE and see if they're any faster this way. If they still suck in WinUAE then it's no use. It usually helps to decide which game is worth working on.