[Libretro] Black square and other issues when using the D3D11 renderer in some games

[bslenul]

Game or games this happens in

UCUS98737 - God of War: Ghost of Sparta

UCUS98653 - God of War: Chains of Olympus

What area of the game / PPSSPP

I saw the issue multiple times on the RetroArch discord server but looks like noone bother creating an issue for it, so here we go. When using the D3D11 renderer in the God of War: Ghost of Sparta with the Libretro core there's a black square appearing in the top-left corner of the screen:

Bisected to b09eb3dd239205e3241d1a7c5923cf30b829454b

edit: It's even worse in God of War: Chains of Olympus, it is just a black screen in-game.

What should happen

No black square.

Logs

No response

Platform

Windows

Mobile device model or graphics card (GPU)

RTX 3060 Ti

PPSSPP version affected

b09eb3d and above (up to ecbbadd while typing this)

Last working version

4ff642c

Graphics backend (3D API)

Direct3D 11

Checklist

• [x] Test in the latest git build in case it's already fixed.
• [x] Search for other reports of the same issue.
• [x] Try resetting settings or older versions and include if the issue is related.
• [x] Try without any cheats and without loading any save states.
• [x] Include logs or screenshots of issue.

[bslenul]

Medievil Resurrection seems affected as well, although it's not as bad as the GoW games:

[Felipefpl]

@hrydgard - Tested both games with D3D11 and i didnt have this problem, i have an intel hd 4000, i only got this error when i closed the emulator:

[bslenul]

To be clear that's only related with the Libretro core, no issue on standalone AFAICT.

At least 2 more games affected:

• LittleBigPlanet, again a black square but also missing effects:

With Vulkan as a comparison:

• GTA Chinatown Wars (screenshot if from a user on RetroArch's subreddit):

[msheehan79]

Another affected game is Ultimate Ghosts 'n Goblins. With D3D11 renderer selected as soon as any enemy sprites start to appear on screen the screen goes black. If the screen is clear of enemies it renders but there is also a black square in the corner. The black screen is very similar to #13737 except now updating the assets on the core wasn't enough to resolve it.

This was tested on RetroArch 1.21.0 using PPSSPP core build 9a50fa4 (Windows 10 x64)

[bslenul]

Oh yeah :x

https://github.com/user-attachments/assets/ae9c8a4b-36db-47b6-9d23-45db26fd2972

The screen turns black every time that weird purple effects appears on screen

https://github.com/user-attachments/assets/6174d773-0fe4-445b-ba1a-c114661f6db4

which doesn't seem normal in the first place and, as you can see from the video, it happens in standalone as well (opened a separate issue for this one: #20728).