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Graphics bug in Hybris

Posted: Sun Jul 05, 2020 2:14 pm
by LamerDeluxe
bPQmPmE.jpg
bPQmPmE.jpg (2.02 MiB) Viewed 4084 times

It works correctly in WinUAE. ROM is from Amiga forever. Config is Amiga 500.

Can anyone here confirm the same problem?

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 3:42 pm
by LeftEmpty
Same little glitch here on two different versions.
Nice catch, might I add, I totally hadn't noticed it :O

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 3:49 pm
by LamerDeluxe
Thanks for confirming! I wonder what could be causing it.

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 8:17 pm
by LamerDeluxe
I've just found a clue in an interview:
The biggest effort on the sprites was the score sprites "on top of everything". The rest of the sprites are grouped in such a way that no problems occur in practice.

The score panel at the top of the screen uses a nice trick where sprites 0 and 1 have their sprite data set and are repositioned horizontally across the screen "racing the beam". Did you come up with that effect or had you seen it in another game?

Good description of what actually goes on technically :-)

This was Torben's idea and was not seen on the Amiga before. There was an immense amount of fiddling to make this fit. It is essentially timed down to the exact processor cycle ;-)
Seems like the score in Hybris serves as a nice CPU timing test.

EDIT: Ooh, I think I have figured it out, IIRC the clock frequency of the Minimig core isn't exactly the same as that of a real Amiga. That would cause a timing error when racing the beam.

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 8:24 pm
by LeftEmpty
You gotta report those cool findings on github!

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 8:58 pm
by Hodor
LeftEmpty wrote: Sun Jul 05, 2020 8:24 pm You gotta report those cool findings on github!
Agreed. It´s the best way to get this issues fixed eventually.

Re: Graphics bug in Hybris

Posted: Sun Jul 05, 2020 9:22 pm
by LamerDeluxe
LeftEmpty wrote: Sun Jul 05, 2020 8:24 pm You gotta report those cool findings on github!
Ah yes, good point, I'll do that tomorrow, it is already late over here.

Re: Graphics bug in Hybris

Posted: Mon Jul 06, 2020 7:17 am
by limi
For those wondering about which interview it was from:

https://codetapper.com/amiga/interviews ... -pedersen/

He was 16 years old at the time he wrote the game.

Re: Graphics bug in Hybris

Posted: Tue Jul 07, 2020 4:00 pm
by LamerDeluxe
limi wrote: Mon Jul 06, 2020 7:17 am For those wondering about which interview it was from:

https://codetapper.com/amiga/interviews ... -pedersen/

He was 16 years old at the time he wrote the game.
Yes, that is correct. Isn't it amazing that they made one of the most professional, polished, arcade-like games on the Amiga, in their spare time, at that age?

EDIT: I've just added an issue for this here: https://github.com/MiSTer-devel/Minimig ... /issues/73