Prince of Persia - Rival Swords (USA) fire graphics glitch

[benderscruffy]

just as the screen is scrolling across the menu screen all the fires glitch up

DUMP DX11.ZIP

[unknownbrackets]

Hm, something is clearly buggy in the dump - might not have pulled the CLUT properly?

From 0x04088000, it does the RGB clut thing. First draw modulates vertex colors, looks fine. Second draw uses an R clut, looks fine. But then it uses a R clut with R masked out, so it essentially erases anything but red.

Hm.

Is the problem this issue is about (not the above dump bug) new or has it always happened?

-[Unknown]

[unknownbrackets]

It might help to see one from where there are no fires / no issues.

-[Unknown]

[hrydgard]

There are weird glitches with fire in the other Prince of Persia game too, Revelations. Fire sprites will suddenly glitch in various ways.

In that game, it looks like bogus texture coordinates coming all the way from the CPU. Could be that the game is mismanaging the data cache somehow...

[unknownbrackets]

Some notes about this here:
#16131 (comment)

A frame dump draws these artifacts so it seems like it's CPU/HLE/something... the values causing this are UVs that seem like they should be 0, but are set to s16 halves of a pointer instead, which is why you get the weird glitching.

-[Unknown]