Surface blur causing visual glitches in darkroom.

[michelklaasen]

Describe the bug

When turning surface blur on and zooming in far into the image, usually at about 400%, visual glitches start to appear. Things like blacked out areas, pixelation, color distortion. The higher the parameters of the module are set, the earlier the glitches appear.

Steps to reproduce

1. Open image in darkroom
2. Turn on surface blur
3. Optional: set parameters to max values
4. Zoom in until 1600%

Expected behavior

Not produce visual glitches when applying surface blur.

Logfile | Screenshot | Screencast

Made a video about it:
https://youtu.be/3IdBJrZ-mt8

Screenshot:

Commit

I don't know

Where did you obtain darktable from?

downloaded from www.darktable.org

darktable version

4.8.1

What OS are you using?

Windows

What is the version of your OS?

Windows 11 Pro 22H2 Build 22621.4317

Describe your system?

Gigabyte Aorus Ultra Gaming x470
AMD Ryzen 9 5900X
32 GB RAM
AMD Radeon 6900XT

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

AMD Radeon 6900XT
Driver Version: 24.20.19.01-241011a-408380C-AMD-Software-Adrenalin-Edition
AMD Windows Driver Version: 32.0.12019.1028
16GB of memory

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

Running script manager with only OpenInExplorer enabled, everything else off.

I only have and use RAW CR3 files from Canon R6 Mark II.

Disabled openCL & openCL drivers in processing settings to see what'd happen. It still glitches, but they look different, more hexagonal.