TEXT4xBRZ produces black lines in Valkyria Chronicles 3's text bubbles in x3 resolution alone

[RafaelTrepaUnCarballo]

Game or games this happens in

ULJM-05781 - Valkyria Chronicles 3 Extra Edition

What area of the game / PPSSPP

During conversations in Valkyria Chronicles 3 (English patched), this texture shader produces black lines in the text bubbles.

This only happens with the specific combination of TEXT4xBRZ and resolution x3, any other filter or resolution will render the dialog textures fine.

What should happen

The background of text bubbles shouldn't show black lines

Logs

No response

Platform

Windows

Mobile device model or graphics card (GPU)

Nvidia Geforce RTX 2060

PPSSPP version affected

v1.17.1-1053

Last working version

No response

Graphics backend (3D API)

Vulkan

Checklist

• [X] Test in the latest git build in case it's already fixed.
• [X] Search for other reports of the same issue.
• [ ] 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.

[hrydgard]

This is a typical case of a game being rendered at a resolution it's not intended for, causing minor wrong texture sampling. I don't think this is likely to be practically solvable, other than picking a combination between texture and rendering upscaling that makes more sense.