Overdrive 2 issues

[sergiobenrocha2]

No rain effect (and sky bugged), no proper sound after sometime and other things

https://www.youtube.com/watch?v=gWVmPtr9O0g

[ekeeke]

I know. We will see once they release their technical infos but I have high doubts this will ever be 100% correctly emulated , it seems to rely on undocumented VDP effects and possibly stuff in analog domain that would be hard to accurately replicate with pure emulation software so I would'nt hold my breath if I were you.

[sergiobenrocha2]

I think you already fount it, for who is interested: https://docs.google.com/document/u/1/d/1ST9GbFfPnIjLT5loytFCm3pB0kWQ1Oe34DCBBV8saY8/pub

[lab313ru]

Any updates?

[ekeeke]

Most of the effects have been working in my private build for quite some time by now (see this thread on spritesmind http://gendev.spritesmind.net/forum/viewtopic.php?f=22&t=2604) but it stills need to be finalized/commited when I got some time as I am not 100% happy with how it was implemented. Hard to find time and motivation to do it however.

[James-F2]

Hi ekeeke.
Do you think fixing GPGX for Overdrive II will make other games run more accurately?

[ekeeke]

What other games are you talking about ? Which ones are inaccurately emulated ?

The reason why Overdrive 2 demo fails in GPGX is precisely because it uses undocumented hardware features or tricks that no commercial games used or relied on and were therefore ignored by the emulator.

Emulating those features will make the emulation more accurate in regard to original hardware but won't change anything for games if they don't rely on them, obviously.

[James-F2]

My question was general, thanks for clarifying.
As far as I can see/hear there are no noticeable bugs/glitches/inaccuracies compared to the hardware with the current state of GPGX.

[lab313ru]

So, it won't be fixed at all?

As I know, every program that the Demo scene ever made just motivates emulator developers to improve their code to be able to play these demos.

[lab313ru]

Position that emulation core should support only commercial games is incorrect.
Because there are many homebrew games (and demos too), and they are playable by the hardware. And the emulator, as it designed, have to emulate hardware accurately.

[ekeeke]

Not sure what you are rambling about but nobody ever said compatibility should be limited to commercial games. Just like with Titan's Overdrive first demo for which the emulator was updated to get it working, it should eventually be modified to get this demo working fine. It's just that, as already explained, I have very limited free time for coding these days (also probably lost some of my motivation after all these years to be fair) so it's still on TODO list (hence why this is kept as an open issue so that anyone willing to improve this emulator can eventually submit fixes for this).

[lab313ru]

Im glad to hear that!:) Thank you)